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Mattia BORGARINO

Professore Associato
Dipartimento di Ingegneria "Enzo Ferrari"

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Pubblicazioni

2023 - Quantum Gates for Electronics Engineers [Articolo su rivista]
Borgarino, Mattia; Badiali, Alessandro
abstract

The design of a solid-state quantum processor is nowadays a hot research topic in microelec-tronics. Like the logic gates in a classical processor, quantum gates serve as the fundamental building blocks for quantum processors. Main goal of the present paper is to deduce the matrix of the main one- and two-qubits quantum gates from the Schrödinger equation. The mathemati-cal formalism is kept as comfortable as possible for electronics engineers. The paper does not cover topics as dissipations, state density, coherence, and state purity. In a similar manner, the paper also deals with the quantum nature of a quantum processor by leveraging on the concept of finite state machine, which is a background notion for any electronics engineer.

2022 - Circuit-Based Compact Model of Electron Spin Qubit [Articolo su rivista]
Borgarino, M.
abstract

Today, an electron spin qubit on silicon appears to be a very promising physical platform for the fabrication of future quantum microprocessors. Thousands of these qubits should be packed together into one single silicon die in order to break the quantum supremacy barrier. Microelectronics engineers are currently leveraging on the current CMOS technology to design the manipulation and read-out electronics as cryogenic integrated circuits. Several of these circuits are RFICs, as VCO, LNA, and mixers. Therefore, the availability of a qubit CAD model plays a central role in the proper design of these cryogenic RFICs. The present paper reports on a circuit-based compact model of an electron spin qubit for CAD applications. The proposed model is described and tested, and the limitations faced are highlighted and discussed.

2021 - Indoor field-trial in X band of a photonics-based multiband radar on a packaged silicon chip [Relazione in Atti di Convegno]
Scotti, F.; Porzi, C.; Ghelfi, P.; Falconi, F.; Haris Amir, M. M.; Maresca, S.; Borgarino, M.; Bogoni, A.
abstract

The paper reports the advancements on a recently presented silicon photonic chip implementing a photonics-based coherent multiband radar transceiver. In this work, the chip has been packaged and engineered for its use in a complete radar system capable of operating up to the X band. The electronic RF frontend and the digital baseband equipment have been developed in order to guarantee performance aligned with the state of the art of conventional radars. A first indoor field trial has been carried out in X band. Range/Velocity acquisitions allow to confirm the radar system effectiveness, posing the base for the next step: the multiband field trial and coherent data fusion.

2021 - On the VCO/Frequency Divider Interface in Cryogenic CMOS PLL for Quantum Computing Applications [Articolo su rivista]
Gira, G.; Ferraro, E.; Borgarino, M.
abstract

The availability of quantum microprocessors is mandatory, to efficiently run those quantum al-gorithms promising a radical leap forward in computation capability. Silicon-based nanostruc-tured qubits appear today as a very interesting approach, because of their higher information density, longer coherence times, fast operation gates, and compatibility with the actual CMOS technology. In particular, thanks to their phase noise properties, the actual CMOS RFIC Phase-Locked Loops (PLL) and Phase-Locked Oscillators (PLO) are interesting circuits to synthe-size control signals for spintronic qubits. In a quantum microprocessor, these circuits should op-erate close to the qubits, that is, at cryogenic temperatures. The lack of commercial cryogenic Design Kits (DK) may make the interface between the Voltage Controlled Oscillator (VCO) and the Frequency Divider (FD) a serious issue. Nevertheless, currently this issue has not been sys-tematically addressed in the literature. The aim of the present paper is to investigate the VCO/FD interface when the temperature drops from room to cryogenic. To this purpose, physi-cal models of electronics passive/active devices and equivalent circuits of VCO and the FD were developed at room and cryogenic temperatures. The modeling activity has led to design guide-lines for the VCO/FD interface, useful in the absence of cryogenic DKs.

2019 - Clock-less 8-bit SAR-ADC with delay-line based digital control circuit [Articolo su rivista]
Borgarino, M.; Giacomini, L.; Luppi, G.; Digiaro, F.; Begueret, J. B.; Verrascina, N.
abstract

Aim of the present paper is to propose an 8 bit SAR-ADC architecture where no external clock signals or on-chip clock generation circuits are used. The digital control circuitry is designed around a delay line constituted by a cascade of monostables. The circuit was implemented in a bulk 350nm CMOS technology. The core of the integrated circuit is about 1500m x 1500m. Post layout simulations for both static (DNL, INL) and dynamic (ENOB, SINAD, THD) Figure-of-Merits are reported. The obtained performance are well aligned with others claimed in the literature for clocked SAR-ADC architectures.

2018 - 130nm CMOS SAR-ADC with Low Complexity Digital Control Logic [Articolo su rivista]
Borgarino, M.; Verrascina, N.; Begueret, J. B.
abstract

This paper reports on an original approach to design the digital control logic of a Successive Approximation Register Analog to Digital Converter, where no sequencers or code registers are used. It turns out a low complexity digital circuitry, which is applied to the design of a 130nm CMOS 8-bit SAR ADC. The simulations demonstrate that the proposed digital control logic correctly works leading to an Analog to Digital Converter exhibiting performances well aligned with the literature in terms of linearity, dissipated power, and energy spent per bit generation.

2017 - On the Transimpedance Amplifiers in the Low frequency Noise Characterizarion [Capitolo/Saggio]
Borgarino, M.; Salvaterra, M.
abstract

The book chapter reports on the troubles may arise when a transimpedance amplifier is applied to the low frequency noise characterization of microelectronics devices. After a short review on the possible approaches to design a transimpedance amplifier, the discussion focused on the issues may arise when a resistive feedback transimpedance amplifier is employed to characterize a noisy two-terminal device. Each issue was described, discussed, and a possible solution was proposed.

2016 - An ULP and Very Efficient Adaptively Biased LDO Regulator for Harvesting Application [Relazione in Atti di Convegno]
Verrascina, Nicola; Begueret, Jean Baptiste; Borgarino, Mattia
abstract

This paper presents an ultra-low power (ULP), low quiescent current, low-dropout regulator with a class-AB and an adaptively biased error amplifier (EA). The high slew rate (SR) and the closed loop bandwidth improve the regulator transient response. Adapting the quiescent current regarding the transient response permits a high current efficiency at steady state. The stability is ensured for the entire output current range (1 µA – 3 mA) and for a maximum output capacitor of 100 pF by the current buffer compensation technique and the standard Miller capacitor compensation. The output voltage is set to 0.8 V with a minimum supply voltage of 0.92 V and a maximum quiescent current of 3.2 µA.

2015 - Mélamgeur résistif à sous-échantillonnage dans la bande 46-65 GHz intégré en technologie BiCMOS 0.13 µm [Relazione in Atti di Convegno]
Viallon, Cristophe; Magnani, Alessandro; Borgarino, Mattia; Parra, Thierry
abstract

Ce papier présente la conception d’un mélangeur résistif doublement-équilibré à sous-échantillonnage optimisé pour fonctionner en bande millimétrique. La puce conçue intègre un générateur d’impulsion analogique sur la voie OL ainsi qu’un amplificateur sur la sortie FI fournissant la charge capacitive nécessaire au bon fonctionnement du mélangeur. Pour une fréquence RF de 58 GHz, le circuit affiche un gain de conversion de 4 dB, soit −8 dB pour le seul mélangeur, ainsi qu’un facteur de bruit de 9,7 dB. Le gain de conversion est constant sur toute la plage 46–65 GHz, ce qui correspond à une gamme de fréquence OL allant de 15 à 21 GHz.

2014 - A K-band BiCMOS low duty-cycle resistive mixer [Relazione in Atti di Convegno]
Magnani, Alessandro; Viallon, C.; Burciu, I.; Epert, T.; Borgarino, Mattia; Parra, T.
abstract

This paper presents a double-balanced down-converter based on a low duty-cycle passive mixer that translates a 18.8 GHz RF signal into a 1 GHz IF signal. The resistive mixer is driven by two analog specially designed pulse generators in order to provide very low conversion losses at high frequencies. The chip has been processed using a 0.13μm BiCMOS technology. With a −1.2dBm input LO power, the overall measured conversion gain is 13.2 dB with an estimated contribution of only −2.1 dB from the passive mixer. The measured noise figure is 6.3 dB. The input-referred 1 dB compression point, hardly limited by the IF amp, is −25.7 dB, with −5dBm for the mixer itself. Total power consumption is 109mW.

2014 - A Low Power Ku Phase Locked Oscillator in Low Cost 130nm CMOS Technology [Articolo su rivista]
Magnani, Alessandro; Borgarino, Mattia; Viallon, C; Parra, T; Jacquemod, G.
abstract

This paper reports on a Ku-band low-power integer N phase locked oscillator designed to investigate the potentialities of a low-cost 130nm CMOS technology for videobroadcasting and radiometryapplications. The design and the characterization of the prototype are described and the main performances are reported and compared to literature. The PLO generates an output tone in the 14.2GHz–15.1GHz frequency range. The phase noise is 68.9dBc/Hz for an offset frequency of 100kHz from a 15GHz carrier, and can be enhanced of about 20dB. The circuit core sinks 23.7mA from 1.2V supply.

2014 - On the limitations of transipedance amplifiers as tools for low-frequency noise characterization [Articolo su rivista]
Borgarino, Mattia; BETTI BENEVENTI, Giovanni; Doga, Valerio; Pavan, Paolo
abstract

An experimental set-up for the characterization of low-frequency noise on two terminal devices is reported. The experimental set-up is based on the use of the commercial transimpedance amplifier (TA) EG&G5182. This paper addresses the influence of the TA on the noise characterization process by describing the TA as a non-ideal operational amplifier with a feedback resistor. The impact of the TA finite input resistance and voltage gain is highlighted through comparison with measurements carried out on resistors and diodes.

2013 - Convertisseur des fréquences BiCMOS en band K basé sur un mélange passif à faibles pertes [Relazione in Atti di Convegno]
A., Magnani; T., Esper; C., Viallon; Borgarino, Mattia; T., Parra
abstract

Ce papier présente la conception d’un convertisseur de fréquences doublement équilibré en bande K pour une conversion de 21GHz vers 1GHz. Pour piloter efficacement le mélangeur résistif constitué de 4 transistors nMOS « froids », le signal d’oscillateur local (OL) est mis en forme par deux générateurs d’impulsion fonctionnant à 20GHz. Ce principe conduit à de faibles pertes de conversion, simulées au niveau du dessin des masques à -2.2dB pour le mélangeur et à 12.7dB pour le convertisseur complet. Ce convertisseur a été réalisé avec la technologie SiGe 0.13 μm BiCMOS de IBM.

2012 - A 12GHz 30mW 130nm CMOS Rotary Travelling Wave Voltage Controlled Oscillator [Articolo su rivista]
G., Jacquemod; F., Ben Abdeljelil; L., Carpineto; W., Tatinian; Borgarino, Mattia
abstract

This paper reports a 12GHz Rotary Travelling Wave (RTW) Voltage Controlled Oscillator designed in a 130nm CMOS technology. The phase noise and power consumption performances were compared with the literature and with telecommunication standards for broadcast satellite applications. The RTW VCO exhibits a -106dBc/Hz@1MHz and a 30mW power consumption with a sensibility of 400 MHz/V. Finally, requirements are given for a PLL implementation of the RTW VCO and simulated results are presented.

2012 - A Phase Noise Performance Study of 15 GHz Phase Locked Loop in 130nm CMOS Technology for DVB-S Application [Relazione in Atti di Convegno]
Magnani, Alessandro; P., Lucchi; T., Parra; G., Jacquemod; Borgarino, Mattia
abstract

The paper investigates the possibility to realize in a low cost 130nm CMOS technology a direct conversion architecture wherethe LNB receives the composite signal from the satellite and provides at the output in one step the I and Q bit stream at the base band. A phase locked loop is investigate to realizethe local oscillator of the receiver. Thetechnology capabilities are investigated for the groundreceiver (e.g. in the DVB-S the down-linkfrequency band is 10.7 – 12.75 GHz) as far as forthe on-satellite receiver (e.g. in the DVB-S the uplink frequency band is 12.9 – 18.4 GHz).

2012 - Comparison between RTW VCO and LC QVCO 12 GHz PLLs [Articolo su rivista]
G., Jacquemod; F., Benabdeljelil; W., Tatinian; Lucchi, Paolo; Borgarino, Mattia; L., Carpineto
abstract

This paper reports comparisons between RTWVCO and LC QVCO 12 GHz PLLs, designed in a 130 nmCMOS technology for satellite communication applications.The phase noise at 1 MHz offset from the carrier is-102 dBc/Hz for the RTW VCO PLL and -98 dBc/Hz forthe LC QVCO PLL, and the power consumption is 39 and17 mW, respectively.

2012 - Esercizi di Elettronica Digitale [Monografia/Trattato scientifico]
Borgarino, Mattia
abstract

Il volume è una raccolta di esercitazioni relative all'analisi di circuiti multivibratori CMOS. L'impostazione del testo è fortemente metodologica con grande rilevanza data al raggiungimento di equazioni di progetto.

2011 - 15 GHz quadrature voltage controlled oscillator in 130 nm CMOS technology [Articolo su rivista]
Lucchi, Paolo; D., Dermit; G., Jacquemod; J. B., Begueret; Borgarino, Mattia
abstract

This paper reports a 15 GHz quadrature voltage controlled oscillator (QVCO) designed in a 130 nm CMOS technology. The phase noise performance of the QVCO and of a phase locked loop (PLL) where the QVCO was inserted were compared with the literature and with telecom standards and commercial products for broadcast satellite applications.

2011 - Comparison between RTW VCO and LC QVC 12 GHz PLLs [Relazione in Atti di Convegno]
F., Benabdeljelil; G., Jacquemod; W., Tatinian; Lucchi, Paolo; Borgarino, Mattia; L., Carpineto
abstract

This paper reports comparisons between RTW VCO and LC QVCO 12 GHz PLLs, designed in a 130 nm CMOS technology. The phase noise at 1MHz offset from the carrier is -102 dBc/Hz for the RTW VCO PLL and -98 dBc/Hz for the LC QVCO PLL, and the power consumption is 39mW and 17 mW, respectively.

2011 - Low phase noise 130nm CMOS ring VCO [Relazione in Atti di Convegno]
Lucchi, Paolo; Borgarino, Mattia; J. B., Begueret; G., Jacquemod
abstract

This paper reports on a voltage controlled ring oscillator fabricated in a 130nm CMOS technology. The oscillator was obtained cascading three delay cells. The schematic of the single delay cell was kept as simple as possible by avoiding the use of cross-coupled pairs. The achieved low phase noise makes the presented ring VCO useful for the design of a correlation radar to be used in medicine for short distance vital signal detection.

2010 - X-band silicon integrated radiometer [Relazione in Atti di Convegno]
Borgarino, Mattia
abstract

The demonstration will be focused on a silicon integrated radiometer working in the X-band. The chip, fabricated in a low cost 0.35um BiCMOS technology, was bonded on a test board. The carried out experiment allows to estimate the temperature sensitivity of the radiometer.

2009 - 15GHz Dual-modulus 130nm CMOS Digital Frequency Divider [Relazione in Atti di Convegno]
F., Chiesi; Dermit, Davide; Lucchi, Paolo; Borgarino, Mattia; G., Jacquemod
abstract

A dual-modulus (2/3) frequency divider working in the Ku band was designed in a 130nm CMOS technology. The fabricated prototype was successfully tested on wafer.

2009 - A 130nm CMOS Tunable Digital Frequency Divider for Dual-Band Microwave Radiometer [Relazione in Atti di Convegno]
Dermit, Davide; F., Ducati; D., Balsamo; Lucchi, Paolo; Borgarino, Mattia; G., Jacquemod
abstract

An inductorless, divide-by-256 fixed-modulus digital frequency divider with programmable input sensitivity, fabricated in 130 nm CMOS bulk process, is presented. Both the absence of inductors and the architecture used allow to obtain a small sized chip. The fabricated frequency divider exhibits two minima in sensitivity at 4.4 GHz and 6.25 GHz consuming about 5.4 mW from a 1.2 V voltage supply. The total active area of the frequency divider is 360umx 115um.

2009 - A 5.2mW Ku-Band CMOS Injection-Locked Frequency Doubler with Differential Input / Output [Relazione in Atti di Convegno]
Monaco, Enrico; Borgarino, Mattia; F., Svelto; Mazzanti, Andrea
abstract

Frequency multipliers in CMOS are key blocks in new emerging applications at μ-waves and mmwaves. Classical solutions, in bipolar technology, exploit the steep non-linear I-V characteristic in order to generate output harmonics at multiples of the input signal frequency. This solution would lead to a very limited gain(or even loss) in CMOS. In this paper we propose a novel circuit topology where a differential pair, in push-push configuration, locks an LC oscillator over a wide frequency range. A behavioral model of the circuit is presented and simple design equations for locking range and output swing are derived. Prototypes, realized in a standard 0.13μm CMOS technology, show 30% locking rangearound 13GHz with 3dBm input power. Suppression of the unwanted input signal and its 3rd harmonic is better than 45dBc. Core power dissipation is 5.2mW only, less than half compared with state of the art.

2009 - Low-Cost Integrated Microwave Radiometer Front-End for Industrial Applications [Articolo su rivista]
Borgarino, Mattia; Polemi, Alessia; Mazzanti, Andrea
abstract

In this paper, a low-cost integrated X-band microwave radiometerfor ground-based applications is presented. The microwave frequencies offer the advantage with respect to the infrared wavelenghts of penetrating all materials, except of metals, allowing detection also through thick smoke and vapor. The design and the characterization of the radiofrequencyelectronics front-end and of the antenna are described. On the basis of the experimental findings, some estimations are reported to evaluate the capabilities of the radiometer in the real practice.

2008 - 65 nm CMOS SSB mixer for UWB synthesiser [Articolo su rivista]
Chiesi, Fabio; Borgarino, Mattia; Mazzanti, Andrea; E., Sacchi; G., Albasini; W., Audoglio
abstract

The present work addresses the design of a 65 nm CMOS wide-band singlesideband mixer for UWB synthesiser. The circuit has been designed inductorless and with few capacitors, in order to save silicon area and, at the same time, to get a mixer independent of the adopted frequency plan and synthesiser architecture.Particular attention has been paid to reducing the spurs as much as possible. In order to address a realistic investigation, the design has accounted also for the corner cases and the possible impairments in the input signals. A comparison with the state-of-the-art of the SSB mixers shows the low power consumption of the present work.

2008 - A broadband RF 65nm CMOS front-end for cable TV reception [Articolo su rivista]
Pifferi, Marco; Ducati, Fabio; H., Brekelmans; L., Tripodi; K., Doris; Borgarino, Mattia
abstract

A novel broadband RF front-end in 65nm CMOS technology is presented. The front-end serves to precondition the incoming RFspectrum for further processing in a cable TV receiver architecture where RF channel selection and down conversion are done in digitaldomain. The analog front-end consists of a broadband highly linear low-noise amplifier followed by a variable gain RF amplifier. An original broadband circuit topology for the amplifiers is adopted.The fabricated front-end exhibits a bandwidth of 50–1050 MHz, a variable gain, which spans from 12 to 37 dB with a 0.2 dB step, anOIP3 of 28.4 dBm (77.5 dBmV), an OIP2 of 65dBm (114 dBmV), and a noise figure of 5.8 dB, dissipating 125mW at 1.2V supply, and a core silicon area of 0.4mm2.

2008 - Ku-Band PLL functional blocks [Relazione in Atti di Convegno]
Ducati, Fabio; Chiesi, Fabio; Dermit, Davide; G., Manni; P., Lucchi; F. B., Abdeljelil; F., Sala; Borgarino, Mattia; G., Jacquemod; W., Tatinian
abstract

Different design solutions in a 130nm CMOS technology for the implementation of critical building blocks for a Ku-band PLL are investigated. In particular, the focus is on the phase-frequency detector, the voltage controlled oscilaltor, and the pre-scaled in the form pf a dual-modulus digital frequency divider.

2008 - Ku-Band Radiometer Antenna Characterization in University Test Facilities [Relazione in Atti di Convegno]
Manni, G; Polemi, Alessia; Borgarino, Mattia; Vincetti, Luca
abstract

2008 - Ku-Band receiver functional blocks [Relazione in Atti di Convegno]
Ducati, Fabio; Chiesi, Fabio; N., Corciulo; Borgarino, Mattia; G., Jacquemod
abstract

The design in 130nm CMOS technology of a Low Noise Amplifier and of a down conversion mixer are presented.

2008 - Self-Oscillation Free 0.35um Si/SiGe BiCMOS X-Band Digital Frequency Divider [Articolo su rivista]
Ducati, Fabio; Pifferi, Marco; Borgarino, Mattia
abstract

This paper reports a divide-by-512 frequency divider designed in a 0.35µm Si/SiGe BiCMOS technology. The 600x1200um2 circuit operates up to 9.5 GHz dissipating 120mW. Self-oscillations are avoided thanks to an original solution based on the use of an RF carrier detector.

2008 - Self-oscillation free 0.35 μm Si/SiGe BiCMOS X-band digital frequency divider [Articolo su rivista]
Ducati, F.; Pifferi, M.; Borgarino, M.
abstract

This letter reports a digital master-slave D-type register divide-by-512 frequency divider designed in a 0.35 μm Si/SiGe BiCMOS technology. The 600 x 1200 μm2 circuit operates up to 9.5 GHz dissipating 120 mW. Self-oscillations are avoided by the use of a radio frequency carrier detector that controls the bias of the last six registers. © 2008 IEEE.

2008 - SiGe BiCMOS X-Band Integrated Radiometer [Relazione in Atti di Convegno]
Ducati, Fabio; Mazzanti, Andrea; Borgarino, Mattia; M., Pifferi
abstract

The paper reports on the design in a 0.35μm SiGe BiCMOS technology, fabrication, and test of a monolithic RF front-end useful for the fabrication of a miniaturized, low cost X-band radiometer. The obtained prototype occupies a silicon area lower than 5mm2, dissipated about 0.5W, and is able to detect a signal as low as -90dBm up to 10GHz.

2008 - System-on-Chip Microwave Radiometer for Thermal Remote Sensing and its Application to the Forest Fire Detection [Relazione in Atti di Convegno]
F., Alimenti; D., Zito; A., Boni; Borgarino, Mattia; A., Fonte; A., Carboni; S., Leone; M., Pifferi; L., Roselli; B., Neri; R., Menozzi
abstract

This research activity focuses on the opportunities offered bythe latest advances in silicon technologies for realizing systemon-chip microwave radiometer. Such a highly integrated, lowcost,radiometer chip could be applied to the environmentalremote sensing and, in particular, to the forest fire detection.The feasibility study is carried-out in two steps. First, a proof ofthe concept is given by means of a discrete-componentradiometer operating at 12.65 GHz. This radiometer exploitsTV-SAT components such as low-noise down-converter and dishantenna. On-field measurements shows a radiometric contrast(increase of the antenna noise temperature due to the fire withrespect to the background) of about 8 K for a wooden fire of0.38 m2 placed 30 m away from the antenna. Then, a single-chip13 GHz radiometer has been designed exploiting a CMOS 90 nmstandard process. The sensor is based on a direct-conversionarchitecture with integrated LNA, Gilbert’s cell mixer and PLLfrequency synthesizer. The IF chain includes an active (gm-C)low-pass filter and a CMOS square-law detector. The circuitsimulations show a total receiver gain of 72 dB, an equivalentinput noise temperature of 105 K and an IF bandwidth of100 MHz.

2007 - 0.35um SiGe BiCMOS X-Band PLO [Relazione in Atti di Convegno]
Pifferi, Marco; Ducati, Fabio; Mazzanti, Andrea; Borgarino, Mattia
abstract

The present paper reports on a X-band PLO designed in a 0.35um SiGe BiCMOS low-cost technology. All blocks of the PLL are integrated in the same chip. The output power is about -7 dBm and the in-band and out-band phase noise resulted to be –75dBc/Hz at an offset frequency of 10kHz and –95dBc/Hz at an offset frequency of 500kHz, respectively. The circuit area is 1350x1100 μm2 and the drained current is 116mA.

2007 - Empirical Nonlinear Noise Models of Field Effect Devices for Microwave Circuit Large-Signal Noise Analysis [Relazione in Atti di Convegno]
Florian, C; TRAVERSO P., A; Borgarino, Mattia; Filicori, F.
abstract

Non linear modeling of state-of-the-art device technologiesboth bipolar and III-VFET-based.

2007 - Low Frequency Noise in Microelectronics [Relazione in Atti di Convegno]
Borgarino, Mattia
abstract

Aim of the tutorial is an overview of the low frequency noise in semiconductor devices as bipolar and MOS transistors under a point of view interesting for people working in the field of integrated circuit design and device model card development. The tutorial is organised in three main sections addressing different facets of the low frequency noise in microelectronics: characterization, modelling, and application.

2006 - A Non-linear Noise Model of Bipolar Transistors for the Phase-Noise Performance Analysis of Microwave Oscillators [Relazione in Atti di Convegno]
Florian, C; TRAVERSO P., A; Borgarino, Mattia; Filicori, F.
abstract

An empirical nonlinear noise model for bipolar transistors, deriving from the charge-controlled nonlinear noise (CCNN) modelling approach, has been developed and implemented. The noise model of a GaInP-GaAs HBT device has been experimentally characterized on the basis of both bias-dependent low-frequency noise data and a set of phase-noise measurements. To this aim, a special-purpose laboratory set-up has been implemented, which allows for phase-noise measurements on an on-wafer device sample under a wide set of different large-signal oscillating conditions. Good agreement was found between the predicted performance and the phase-noise measurements carried out on a MMIC VCO designed by using the proposed non-linear noise model.

2006 - A Single-Chip 5GHz WLAN Transmitter in 0.35um Si/SiGe BiCMOS Technology [Relazione in Atti di Convegno]
F., Alimenti; Borgarino, Mattia; R., Codeluppi; V., Palazzari; M., Pifferi; L., Roselli; A., Scorzoni; Fantini, Fausto
abstract

The paper deals with the design of a 5GHz WLAN heterodyne transmitter for domotic applications. The transmitter has been realized in commercial 0.35mum Si/SiGe BiCMOS technology with the purpose to reduce cost while achieve an high integration level. Measurements on a prototype, wire-bonded on a low-cost FR4 printed circuit board, have been carried-out showing an overall linear gain of 14dB an input referred compression point of -6.5dBm and a third-order input intercept point of +2.7dBm

2006 - An empirical bipolar device nonlinear noise modeling approach for large-signal microwave circuit analysis [Articolo su rivista]
Pa, Traverso; C., Florian; Borgarino, Mattia; F., Filicori
abstract

An empirical bipolar transistor nonlinear noise model for the large-signal (LS) noise analysis of microwave circuits is described. The model is derived according to the charge-controlled nonlinear noise behavioral modeling approach, and includes nonlinearly controlled equivalent noise (EN) generators describing the low-frequency (LF) noise up-conversion encountered in LS RF operation. LS-modulated shot-noise sources and parametric LF noise in parasitic resistors are also taken into account for improved model accuracy. Details for the implementation of the. proposed cyclostationary EN generators in the framework of a computer-aided design tool are presented. As an application example, a simplified version of the proposed nonlinear noise model for two GalnP-GaAs HBTs has been formulated and empirically characterized on the basis of both bias-dependent LF noise and phase-noise measurements. Measured and simulated noise performance of a monolithic voltage-controlled oscillator over a set of different operating conditions is shown for the validation of the proposed approach.

2006 - Bias Dependent, Compact Low-Frequency Noise Model of GaInP/GaAs HBT: Experimental Identification and CAD Implementation [Relazione in Atti di Convegno]
Borgarino, Mattia; N., Corciulo; C., Florian; P. A., Traverso; Fantini, Fausto; F., Filicori
abstract

In the present paper, the experimental identification of a compact low-frequency noise model of GaInP/GaAs Heterojunction Bipolar Transistors and its implementation in a widely employed RF CAD software is described. The model is analytical so that its CAD implementation does not require look-up tables. In addition to the usual control of the noise sources through the DC or the mean value of the base current, the model reported in the present work is flexible enough to allows for the control of the noise sources through the instantaneous value of the base current.

2006 - High linearity CMOS mixer for domotic 5 GHz WLAN sliding-IF receivers [Articolo su rivista]
M., Pifferi; Borgarino, Mattia; R., Codeluppi; F., Alimenti
abstract

The present paper describes the design of a 1.1 GHz CMOS, fully differential, down conversion mixer to be used as a second down conversion mixer in an integrated transceiver for 5 GHz domotic WLAN. The circuit was implemented in a 0.35um SiGe BiCMOS technology and designed with the aim of getting high linearity without excessive reduction in the conversion gain. The obtained circuit exhibits a conversion gain of -1 dB and a third-order input intercept point of +10 dBm. Biased at 3 V, it dissipates 45 mW. (c) 2006 Elsevier Ltd. All rights reserved.

2006 - Microstrip Array Antenna Design for a Radiometric Ground-Based Fire Detection Application [Relazione in Atti di Convegno]
Vincetti, Luca; G., Borsari; Maini, Moreno; Polemi, Alessia; Borgarino, Mattia
abstract

In this paper, a first investigation on critical issues for a fire-detection ground-based Ku-band radiometer design is addressed. A printed technology with standard dielectrics has been employed, in order to reach low cost, simplicity in realization and easy integrability with the electronic front-end. The antenna has been designed as an arrays of patches, where number of elements, spacings and feeding currents have been optimized to fulfill requirements of low side lobe level and good crosspolarization.For the radio frequency front-end, the receiver architecture is a direct-conversion topology, because it is well suited to be monolithically integrated in a single chip.

2006 - Microwave large-signal effects on the low-frequency noise characteristics of GaInP/GaAs HBTs [Articolo su rivista]
Borgarino, Mattia; C., Florian; P. A., Traverso; F., Filicori
abstract

This paper addresses both experimentally and through simulations the effects of a microwave tone on the low-frequency noise properties of GaInP/GaAs heterojunction bipolar transistors. The aim is to contribute to the still unsolved controversy on which modulation strategy should be adopted for the low-frequency noise sources when they should face large signal conditions, as in the cases of oscillators and mixers. An approach similar but not equal to the modulated stationary noise model has been adopted for three different kinds of noise source modulation strategy in the frame of a bias-dependent compact low-frequency noise model.

2006 - Non-linear Measurement-Based Noise Models of Electron Devices for Low Phase-Noise Oscillator Design [Relazione in Atti di Convegno]
C., Florian; P., A: Traverso; F., Filicori; Borgarino, Mattia
abstract

The shortcourse addresses the non-linear modeling of the low frequency noise properties of microwave transistors for oscillator design purposes.

2005 - Building Blocks for a 5GHz WLAN Transmitter in 0.35mm Si/SiGe BiCMOS [Relazione in Atti di Convegno]
F., Alimenti; Borgarino, Mattia; R., Codeluppi; Palazzari, V.; M., Pifferi; L., Roselli; A., Scorzoni
abstract

The work deals with the basic building blocks of a 5GHz WLAN transmitter for domotic applications. These building blocks have been designed exploting commercial 0.35um Si/SiGe BiCMOS technology with the purpose to avoid the necessity of external components. On-wafer measurements have been carried out on the realized prototypes showing a good agreement with simulated performances.

2005 - Design of RFIC's in 0.35um Si/SiGe BiCMOS Technology for a 5GHz Domotic Transmitter [Relazione in Atti di Convegno]
F., Alimenti; Borgarino, Mattia; R., Codeluppi; V., Palazzari; Pifferi, Marco; L., Roselli; A., Scorzoni; Fantini, Fausto
abstract

The work deals with the basic building blocks of a 5GHz WLAN transmitter for domotic applications. These building blocks have been designed exploiting a commercial 0.35um Si/SiGe BiCMOS technology with the purpose to avoid the necessity of external components. On-wafer measurements have been carried-out on the realized prototypes showing a good agreement with simulatedperformances.

2005 - Design of RFICs in 0.35μm Si/SiGe BiCMOS technology for a 5 GHz domotic transmitter [Relazione in Atti di Convegno]
Alimenti, F.; Borgarino, M.; Codeluppi, R.; Palazzari, V.; Pifferi, M.; Roselli, L.; Scorzoni, A.; Fantini, F.
abstract

This paper deals with the basic building blocks of a 5GHz WLAN transmitter for domotic applications. These building blocks have been designed exploiting a commercial 0.35μm Si/SiGe BiCMOS technology with the purpose to avoid the necessity of external components. On-wafer measurements have been carried-out on the realized prototypes showing a good agreement with simulated performances.

2005 - Design of RFICs in 0.35μm Si/SiGe BiCMOS technology for a 5GHz domotic transmitter [Relazione in Atti di Convegno]
Alimenti, F.; Borgarino, M.; Codeluppi, R.; Palazzari, V.; Pifferi, M.; Roselli, L.; Scorzoni, A.; Fantini, F.
abstract

This paper deals with the basic building blocks of a 5GHz WLAN transmitter for domotic applications. These building blocks have been designed exploiting a commercial 0.35μm Si/SiGe BiCMOS technology with the purpose to avoid the necessity of external components. On-wafer measurements have been carried-out on the realized prototypes showing a good agreement with simulated performances.

2005 - Full direct low frequency noise characterization of GaAs heterojunction bipolar transistors [Articolo su rivista]
Borgarino, Mattia
abstract

The present paper focuses on solutions of the experimental difficulties rising up when a full low frequency noise characterization of bipolar transistors exhibiting high noise levels and low input dynamic input impedances is carried out using a direct characterization technique. First, a typical direct characterization experimental set-up is introduced pointing out the difficulties to be faced when a high noise, low input impedance transistor is addressed. Then, an improved version of the experimental set-up is proposed and successfully applied to AlGaAs/GaAs heterojunction bipolar transistors.

2005 - Low Noise, Low Interference Automated Bias Networks for Low Frequency Noise Characterization Set-Up's [Relazione in Atti di Convegno]
Borgarino, Mattia; M., Rossi; Fantini, Fausto
abstract

The work reports on the implementation of electromechanical bias networks to be employed in an automated experimental set-up for the low frequency noise characterization of bipolar transistors. The obtained bias networks allowed to improve theautomatization degree of the experimental set-up, reducingtherefore the time and the efforts for the systematic characterization necessary for the identification of nonlinearlow frequency noise models. The electromechanical bias networks were successfully applied to the systematic characterization at wafer level of microwave GaInP/GaAs heterojunction bipolar transistors.

2004 - C Band DROs Using Microwave Bipolar Devices [Relazione in Atti di Convegno]
C., Florian; M., Pirazzini; G., Vannini; A., Santarelli; C., Angelone; M., Paparo; Borgarino, Mattia; F., Filicori
abstract

A silicon self-aligned-emitter bipolar process from STMicroelectronics for very high efficiency handsets power applications has been used to build two Dielectric Resonator Oscillators. Despite this technology addresses the mobile telephony frequency range at 1.8GHz, the oscillators generate a stable reference at 6GHz and 7.5GHz with good phase noise performance. A low frequency noise model has been identified and implemented in a Gummel Poon BJT nonlinear model. A design technique to optimize stability and phase noise performances has been used. The DROs exhibit phase noise of -116dBc/Hz and -107dBc/Hz at 10KHz offset from the carrier at 6GHz and 7.5GHz, respectively.

2004 - Hydrogen induced degradation in GaInP/GaAs HBTs revealed by low frequency noise measurements [Relazione in Atti di Convegno]
J. G., Tartarin; L., Escotte; Borgarino, Mattia; R., Plana; J., Graffeuil
abstract

One of today’s challenges to enable the improved electrical performances and reliability of microelectronic devices consists in controlling impurities contamination : hydrogen appears to be present in most (if not all) the processes steps of the devices making (ambient atmosphere, or associated with AsH3 -VPE or AsCl3 -VPE for example in GaAs based devices, …). Hydrogen induced reliability has already been investigated for many technologies Si or GaAs based ((C)MOS, FET, HEMT, PHEMT as well as HBT devices). These effects of hydrogen on electrical behavior and on long term reliability are very difficult to understand because of the different nature and ionic association of hydrogen (H, H+, H-, H2, or associated with impurities (Ge-H, Be-H, C-H, …). Most of these studies make use of IR, SIMS, Hall measurements : in this paper, we use low frequency noise measurements, associated with static as well as dynamic characterization to identify the degradation process in GaInP/GaAs Heterojunction Bipolar Devices (HBT provided by Thomson LCR). Firstable, we will present the influence of passivation (SiN and GaInP ledge) on the reliability associated with Hydrogen : low frequency noise measurements will be performed in the range of 250Hz to 100 kHz. The noise spectra evolutions (current and voltage noise sources at the input of the device, and their correlation) will allow us to identify the activation process responsible of the static and dynamic rise and fall of the HBT’s current gain. C-H complexes have been proved to be the process responsible of this degradation. Additive reliability tests have been performed on two sets of devices (featuring different emitter length) under two distinct stocking conditions (temperature and biasing of the devices) leading to different junctions temperatures : low frequency and high frequency noise measurements, associated with static and dynamic S parameters measurements will lead to the same conclusions about the hydrogen chemical reaction. C-H complexes breaking, and diffusion of H towards the extrinsic surface of the device have been observed. Sealed devices have proved to get the same degradation signature than on wafer devices : Hydrogen is assumed to be present in high concentration levels in the device layers, and reacts under thermal and electrical stress. This study will also present the emitter orientation effects on the reliability, i.e. of the piezoelectric contribution both to electrical performances and reliability level of the device.

2004 - Identification procedures for the charge-controlled nonlinear noise model of microwave electron devices [Relazione in Atti di Convegno]
F., Filicori; P. A., Traverso; C., Florian; Borgarino, Mattia
abstract

The basic features of the recently proposed Charge-Controlled Non-linear Noise (CCNN) model for the prediction of low-to-high-frequency noise up-conversion in electron devices under large-signal RF operation are synthetically presented. It is shown that the different noise generation phenomena within the device can be described by four equivalent noise sources, which are connected at the ports of a "noiseless" device model and are non-linearly controlled by the time-varying instantaneous values of the intrinsic device voltages. For the empirical identification of the voltage-controlled equivalent noise sources, different possible characterization procedures, based not only on conventional low-frequency noise data, but also on different types of noise measurements carried out under large-signal RF operating conditions are discussed. As an example of application, the measurement-based identification of the CCNN model for a GaInP heterojunction bipolar microwave transistor is presented. Preliminary validation results show that the proposed model can describe with adequate accuracy not only the low-frequency noise of the HBT, but also its phase-noise performance in a prototype VCO implemented by using the same monolithic GaAs technology.

2004 - Semi-Automated Experimental Set-Up CAD-oriented Low Frequency Noise Modeling of Bipolar Transistors [Relazione in Atti di Convegno]
Borgarino, Mattia; A., Bogoni; Fantini, Fausto; M., Peroni; C. A., Cetronio
abstract

The present work addresses the hardware and software development of a semi-automated experimental set-up devoted to the extraction of low frequency noise compact models of bipolar transistors for microwave circuit applications (e.g. oscillators). The obtained experimental setup is applied to GaInP/GaAs Heterojunction Bipolar Transistors.

2003 - High electric field induced degradation of the DC characteristics in Si/SiGe HEMT's [Articolo su rivista]
J., Kuchenbecker; Borgarino, Mattia; M., Zeuner; U., Konig; R., Plana; Fantini, Fausto
abstract

We report, for the first time, results on the reliability of Si/SiGe HEMT´s. The present work addresses the high electric field stress effects on the DC characteristics. In particular, we report the variations of the output characteristics (drain and gate current), of the transconductance, of the threshold voltage, and of the breakdown voltage. Subsequently, possible degradation mechanisms are presented. The observed variations are discussed in comparison with similar experiments carried out on PHEMT´s issued of the III-V technology. Keywords: HEMT´s, Reliability, SiGe, DC Characteristics

2003 - Topology investigation for the low frequency noise compact modelling of bipolar transistors [Articolo su rivista]
Borgarino, Mattia
abstract

The low frequency noise (LFN) properties of bipolar transistors are investigated in terms of equivalent input referred, partially correlated noise generators. These properties are studied as a function of the intrinsic noise sources and of the small-signal model topology. Topology invariance and identity properties are identified and their practical implications on the LFN modelling of bipolar transistors are assessed. (C) 2003 Elsevier Science Ltd. All rights reserved.

2002 - Appunti di Microelettronica [Monografia/Trattato scientifico]
Fantini, Fausto; Borgarino, Mattia
abstract

Il testo fornisce un quadro sintetico delle tecnologie impiegate in microelettronica.

2002 - Degradation based long-term reliability assessment for electronic components in submarine applications [Articolo su rivista]
V., Lista; P., Garbossa; T., Tomasi; Borgarino, Mattia; Fantini, Fausto; L., Gherardi; A., Righetti; M., Villa
abstract

Submarine Communication Systems require usage of high-rel components to guarantee long term reliability. A standard reliability assessment, based on observed failures during test, may be achieved only employing a very large number of component-hour, which is often unaffordable. An alternative reliability technique is proposed in this paper, based on the degradation monitoring of the components most relevant electrical parameters, subjected to different test flows. This analysis leads to a quantitative estimate of the components failure rate. (C) 2002 Elsevier Science Ltd. All rights reserved.

2002 - Low frequency noise characterization and modeling of microwave bipolar devices : application to the design of low phase noise oscillator [Relazione in Atti di Convegno]
L., Bary; G., Cibiel; I., Telliez; J., Rayssac; A., Rennane; C., Boulanger; O., Llopis; Borgarino, Mattia; R., Plana; J., Graffeuil
abstract

This paper addresses advanced low frequency noise measurements and modeling of SiGe HBTs. Results have been implemented into a nonlinear Gummel Poon model which has been validated through the design of a DRO made of an integrated SiGe negative resistance in the 10 GHz range. We have obtained phase noise of -105 dBc/Hz at 10 kHz offset, which is close to the state of the art, and we have demonstrated a design technique that provides an accurate phase noise prediction.

2002 - Low frequency noise characterization and modeling of microwave bipolar devices: Application to the design of low phase noise oscillator [Relazione in Atti di Convegno]
Bary, L.; Cibiel, G.; Telliez, I.; Rayssac, J.; Rennane, A.; Boulanger, C.; Llopis, O.; Borgarino, M.; Plana, R.; Graffeuil, J.
abstract

This paper addresses advanced low frequency noise measurements and modeling of SiGe HBTs. Results have been implemented into a non linear Gummel Poon model which has been validated through the design of a DRO made of an integrated SiGe negative resistance in the 10 GHz range. We have obtained phase noise of -105 dBc/Hz at 10 kHz offset, which is close to the state of the art, and we have demonstrated a design technique that provides an accurate phase noise prediction.

2002 - Low-Frequency Noise Characterisation of AlGaAs/GaAs HBT’s [Relazione in Atti di Convegno]
Borgarino, Mattia; M., Peroni; A., Cetronio; Fantini, Fausto
abstract

In the present paper we evaluated the fabrication process of AlGaAs/GaAs heterojunction Bipolar Transistors (HBT's) by means of low frequency noise characterizations carried out in the 100Hz-100kHz frequency range. We investigated the spectra of the base current fluctuations. The obtained results are compared with the data reported in the literature. The fabrication technology and the experimental set-up are briefly described.

2002 - The Correlation Resistance for Low-Frequency Noise Compact Modeling of Si/SiGe HBT's [Articolo su rivista]
Borgarino, Mattia; L., Bary; D., Vescovi; R., Menozzi; A., Monroy; M., Laurens; R., Plana; Fantini, Fausto; J., Graffeuil
abstract

The measurement of the correlation between the noise generators is a mandatory issue for the low-frequency noise modeling of bipolar transistors, and it is recognized as a very hard experimental task. In the present work, we introduce the concept of correlation resistance and we demonstrate that it can be usefully employed as a guideline for the low-frequency noise modeling in terms of intrinsic noise sources. As a proof of concept, the investigation technique is applied to submicron, BiCMOS-compatible Si/SiGe heterojunction bipolar transistors. It is pointed out that a satisfactory description of the transistor low-frequency noise behavior can be obtained by taking into account noise sources associated with surface recombination/fluctuation in the extrinsic base region.

2001 - Comprehensive experimental and numerical assessment of hot electron reliability of power HFETs [Abstract in Atti di Convegno]
R., Menozzi; G., Sozzi; Verzellesi, Giovanni; Borgarino, Mattia; Canali, Claudio; C., Lanzieri
abstract

The technology of III-V FETs is nowadays mature, and traditional wear-out mechanisms are no longer a reliability bottleneck. On the other hand, field related degradation and failures have gained increasing relevance. However, the physical understanding of these degradation mechanisms and their relationship with FET design is still underdeveloped. The aim of this paper is to contribute to the comprehension of high-field reliability issues in GaAs power HFETs by coupling experiments with numerical simulations.

2001 - Experimental/numerical investigation of the physical mechanisms behind high-field degradation of power HFETs and their implications on device design [Relazione in Atti di Convegno]
R., Menozzi; G., Sozzi; Verzellesi, Giovanni; Borgarino, Mattia; C., Lanzieri; Canali, Claudio
abstract

In a previous paper we showed how simple drift-diffusion simulations backed up the hypothesis of electron trapping at the device surface between gate and drain as a mechanism able to consistently explain all of the experimentally observed degradation modes following a high-field (hot carrier) stress. This paper expands on such previous findings by showing: (i) simulation results of HFETs with different recess geometries, and their implications on breakdown voltage and reliability; (ii) a detailed experimental and numerical investigation of surface trapping effects such as gate lag, transconductance frequency dispersion, and drain current kink, and their relationship with device degradation.

2001 - Failure mechanisms in compound semiconductor electron devices [Capitolo/Saggio]
Fantini, Fausto; R., Menozzi; Borgarino, Mattia; L., Cattani; D., Dieci
abstract

In this chapter, we review the main failure mechanisms that affect advanced compound semiconductor electron devices such as high electron mobility transistors (HEMTs) and heterostructure bipolar transistors (HBTs).

2001 - Gate-lag effects in AlGaAs/GaAs power HFET's [Articolo su rivista]
Borgarino, Mattia; G., Sozzi; Mazzanti, Andrea; Verzellesi, Giovanni
abstract

Gate-lag effects have been characterized in as-fabricated and hot-carrier-stressed power AlGaAs/GaAs HFET's and then compared with transconductance frequency dispersion measurements and studied by means of numerical simulations accounting for the occupation dynamics of surface deep-acceptor traps. We have found a clear direct correlation between the amount of gate-lag and of transconductance dispersion. The gate-lag tam-off transients of increasingly degraded devices have been accurately simulated by suitably increasing the surface trap density. (C) 2001 Elsevier Science Ltd. All rights reserved.

2001 - Hot Carrier Effects in Si/SiGe HBT's [Articolo su rivista]
Borgarino, Mattia; J., Kuchenbecker; Jg, Tartarin; L., Bary; T., Kovacic; R., Plana; Fantini, Fausto; J., Graffeuil
abstract

Life tests were performed at room temperature on Si-SiGe HBTs by reverse biasing the base-emitter junction under open collector conditions. The effects on the DC, the low-frequency noise, and the microwave characteristics were investigated both by the analysis of experimental data and by simulations and analytical models. The stress-induced surface damage close to the emitter perimeter was identified to be the degradation mechanism mainly responsible for the variations observed, in all the investigated parameters

2001 - Impact of gamma irradiation on the RF phase noise capability of UHV/CVD SiGe HBTs [Articolo su rivista]
G., Niu; J. B., Juraver; Borgarino, Mattia; Z., Jin; J. D., Cressler; R., Plana; O., Llopis; S., Mathew; S., Zhang; S., Clark; A. J., Joseph
abstract

This work investigates the effects of gamma irradiation on the residual phase noise of SiGe HBTs. The excellent phase noise capabioity of SiGe HBT is retained after 1Mrad(si) irradiation. The observed radiation hardness is attributed to the minor changes in the low frequency noise and device nonlinearities after irradiations, as well as the nonlinearity cancellation mechanism. The radiation-induced defects do not significantly add to the low frequency noise in these SiGe HBTs, even though they produce a large space-charge-region recombination component in the base current. The inherent excellent linearity of these SiGe HBTs makes the up-conversion from device low frequency noise to phase noise inefficient, and helps to retain the low pahse noise after irradiations.

2001 - Investigation of the Hot-Carrier Degradation in Si/SiGe HBT’s by Intrinsic Low Frequency Noise Source Modeling [Relazione in Atti di Convegno]
Borgarino, Mattia; Kuchenbecker, J.; Tartarin, J. C.; Bary, L.; Kovacic, S.; Plana, R.; Menozzi, R.; Fantini, Fausto; Graffeuil, J.
abstract

The characterization of the excess low-frequency noise (LFN) properties of electronic devices is a useful tool in the field of reliability physics, because LFN is related to the interactions between charge carriers and material imperfections and defects. The LFN behavior of a bipolar transistor can be described in terms of extrinsic or intrinsic noise sources. The noise representation based on intrinsic noise sources allows more insight, because each source is associated with a particular transistor region. The availability of an intrinsic noise source model therefore allows to locate the degradation occurring during a life test.

2001 - Low Phase Noise, Fully Integrated Monolithic VCO in X Band Based on HBT Technology [Relazione in Atti di Convegno]
Z., Ouarch; F., Arlot; Borgarino, Mattia; M., Prigent; L., Bary; M., Camiade
abstract

This paper presents a very low phase noise wide band fully integrated VCO in X band. It is based on UMS HBT technology (HB20P process). This circuit has been realized in the frame of ARGOS project in order to carry out a low phase noise frequency synthesizer. HB20P transistor and varactor nonlinear models have been extracted from pulsed measurements. Furthermore, HBT low frequency noise measurements have been performed to evaluate noise sources and then to optimize the operating point in the design. According to these characterizations, we have realized a fully MMIC VCO providing good phase noise performances -(90 dBc/Hz @ 100 KHz), in a wide frequency band (15%) and in a wide temperature range -(40°C<+65°C).

2001 - Noise behavior in SiGe devices [Articolo su rivista]
M., Regis; Borgarino, Mattia; L., Bary; O., Llopis; J., Graffeuil; L., Escotte; U., Koenig; R., Plana
abstract

This paper presents an overview of SiGe technologies and their corresponding noise properties both in the high frequency and low frequency range. We demonstrate that SiGe bipolar technology exhibits impressive low frequency noise performance with an excess corner noise frequency in the 1kHz range. These results have been validated by low phase noise microwave oscillators based on SiGe material.

2001 - Reliability investigation in SiGe HBT’s [Relazione in Atti di Convegno]
J., Kuchenbecker; Borgarino, Mattia; L., Bary; G., Cibiel; O., Llopis; J. G., Tartarin; J., Graffeuil; S., Kovacic; J. L., Roux; R., Plana
abstract

This paper addresses some reliability properties of SiGe HBTs. We first verified that no major problems were related to the SiGe layer through DC life tests. In the second step, we investigated the hot carrier influence on the DC, noise and microwave properties of these devices. We found that some degradation was occurring at the extrinsic base region in the vicinity of the emitter associated with some surface recombination. These assumptions have been described by physical simulations and confirmed by low frequency noise characterization. Finally, it has been demonstrated that microwave properties are affected by the mechanism and we propose a bias method that results in its minimization.

2001 - Reliability physics of compound semiconductor transistors for microwave applications [Articolo su rivista]
Borgarino, Mattia; R., Menozzi; D., Dieci; L., Cattani; Fantini, Fausto
abstract

This paper reviews the reliability problems of compound semiconductor transistors for microwave applications. These devices suffer from specific failure mechanisms, which are related to their limited maturity, with the exception of the GaAs MESFETs, which exhibit a stable technology and an assessed reliability. The metallizations employed in high electron mobility transistors (HEMTs) already benefit from this assessment. However, HEMT are affected by concerns related to hot carriers and impact ionization. The trapping of carriers and the generation of defects in the different layers are responsible for the observed instabilities. The stability of the base dopant is the main reliability concern for heterojunction bipolar transistors (HBTs). Beryllium outdiffuses from the base into the emitter and causes device degradation. Carbon has a lower diffusivity, but is affected by the presence of hydrogen, which prompts gain variations. Finally the hot carriers reliability concern in SiGe HBTs is briefly reviewed. (C) 2001 Elsevier Science Ltd. All rights reserved.

2001 - Surface effects on turn-off characteristics of AlGaAs/GaAs HFETs [Articolo su rivista]
E., Tediosi; Borgarino, Mattia; Verzellesi, Giovanni; R., Menozzi; G., Sozzi
abstract

The gate-lag turn-off transient of as-fabricated and hut-carrier stressed power AlGaAs/GaAs HFETs is addressed by quantitatively comparing experimental data with device simulations accounting for the occupation dynamics of surface deep-acceptor trays. Gate-lag waveforms of increasingly degraded devices can be accurately simulated by suitably increasing the surface trap density.

2001 - The low frequency noise in electron devices: an engineering sight [Relazione in Atti di Convegno]
Borgarino, Mattia; Fantini, Fausto
abstract

Not available

2001 - Transimpedance amplifier based full low frequency noise characterization set-up for Si/SiGe HBTs [Articolo su rivista]
L., Bary; Borgarino, Mattia; R., Plana; T., Parra; S., Kovacic; H., Lafontaine; J., Graffeuil
abstract

An experimental setup, based on current/voltage conversion through transimpedance amplifiers (TAs), has been implemented for the direct full low-frequency noise (LFN) characterization of Si/SiGe heterojunction bipolar transistors (HBTs) in terms of base and collector short-circuit current noise sources. This setup performs a full characterization, as it measures simultaneously the two noise current sources and their correlation, thanks to an original technique based on the specific properties of a specially designed buffer amplifier using a low-noise common-base bipolar transistor (CB BJT). By means of translation formulae, the obtained measurements are compared with those carried out with a multi-impedance technique. They show a good agreement both for the noise sources spectral densities and for their correlation. The TA-based setup provides enhanced capabilities in terms of measurement speed and remote control potentialities.

2000 - Dynamic thermal characterization and modeling of packaged AlGaAs/GaAs HBT's [Articolo su rivista]
M., Busani; R., Menozzi; Borgarino, Mattia; Fantini, Fausto
abstract

In this work we show a method for the thermal dynamic modeling of packaged HBT's, The method employs a calibration step featuring pulsed measurements at different temperatures, and is based upon a 3-stage thermal resistance-capacitance model that describes the chip-solder-case system. A current pulse generator was designed and assembled in-house for pulsed characterization down to the microsecond range. The model was used to simulate the thermal transients of the collector current from the microsecond range to hundreds of seconds, for several different bias points in the forward active region, consistently showing a good match with the measured characteristics.

2000 - Evaluation of the hot carrier/ionizing radiation induced effects on the RF characteristics of low-complexity SiGe heterojunction bipolar transistors by numerical simulation [Articolo su rivista]
J., Kuchenbecker; Borgarino, Mattia; A., Coustou; R., Plana; J., Graffeuil; Fantini, Fausto
abstract

The hot carriers (HC)/ionizing radiation (IR) effects on the DC and RF characteristics of Si/SiGe HBTs have been investigated by numerical simulations. Once reproduced the typical DC degradation modes, the changes in the scattering (S) parameters were investigated up to 30 GHz. The degradation is caused by the increase of the Shockley-Hall-Read (SHR) surface recombination located around the emitter perimeter. Simulations were carried out by keeping the base or the collector current as they were before introducing the degradation mechanism. When the base current is kept constant, the most relevant effect is a reduction of \ S-21\ while the other S-parameters exhibit only minor changes. On the other hand, no remarkable hot carrier/ionizing radiation effects on the RF characteristics were observed when the collector current was kept constant. (C) 2000 Elsevier Science Ltd. All rights reserved.

2000 - Excess noise modelling of SiGe BicMOS devices [Relazione in Atti di Convegno]
Ibarra, J.; Vescovi, D.; Bary, L.; Borgarino, M.; Kovacic, S.; Lafontaine, H.; Graffeuil, J.; Plana, R.
abstract

This paper presents an exhaustive characterization of the low frequency noise behavior of SiGe HBT which is used to locate the 1/f noise sources within the device. We demonstrate that 1/f noise sources are present at the emitter base junction, at the collector terminal and at the base and emitter resistance.

2000 - Hot carrier effects on the correlation resistance in Si/SiGe heterojunction bipolar transistors [Relazione in Atti di Convegno]
Borgarino, M.; Bary, L.; Kuchenbecker, J.; Tartarin, J. G.; Lafontaine, H.; Kovacic, T.; Plana, R.; Graffeuil, J.; Fantini, F.
abstract

In this paper the effects of hot carrier on the correlation resistance in SiGe HBT's are investigated. Before the stress the correlation resistance was found to be comparable with the access series resistance while, after the stress, the correlation resistance decreases and the access series resistance increases. This increase suggests that the stress degrades the access regions of the transistor. On the other hand, the observed behaviour of the correlation resistance is explained in terms of an intrinsic noise source, Π-topology based low frequency noise model. It is shown that the correlation resistance is a useful indicator of surface recombination mechanisms. In particular, one intrinsic noise source in the model is associated with the degradation of the extrinsic base surface around the emitter perimeter.

2000 - Hot carriers Effects on the correlation resistance in Si/SiGe Heterojucntion Bipolar Transistors [Relazione in Atti di Convegno]
Borgarino, Mattia; L., Bary; J., Kuchenbecker; J. G., Tartarin; H., Lafontaine; S., Kovacic; R., Plana; J., Graffeuil; Fantini, Fausto
abstract

In this paper the effects of hot carrier on the correlation resistance in SiGe HBT's are investigated. Before the stress the correlation resistance was found to be comparable with the access series resistance while, after the stress, the correlation resistance decreases and the access series resistance increases. This increase suggests that the stress degrades the access regions of the transistor. On the other hand, the observed behaviour of the correlation resistance is explained in terms of an intrinsic noise source, Π-topology based low frequency noise model. It is shown that the correlation resistance is a useful indicator of surface recombination mechanisms. In particular, one intrinsic noise source in the model is associated with the degradation of the extrinsic base surface around the emitter perimeter.

2000 - Low frequency noise behavior of SiGe BICMOS HBT and their related phase noise performances [Relazione in Atti di Convegno]
Regis, M.; Flotats, E.; Borgarino, M.; Kovacic, S.; Lafontaine, H.; Llopis, O.; Tournier, E.; Bary, L.; Plana, R.
abstract

This paper deals with low frequency noise investigation in SiGe BiCMOS devices. We found that five 1/f sources are involved. When appropriate design is done 1/f corner noise frequency lower than 1/kHz has been obtained. These results have been validated through 4 GHz oscillator featuring very low phase noise magnitude.

2000 - Low frequency noise behaviour of InP/InGaAs heterojunction bipolar waveguide phototransistors [Articolo su rivista]
Borgarino, M.; Plana, R.; Fendler, M.; Vilcot, J. P.; Mollot, F.; Barette, J.; Decoster, D.; Graffeuil, J.
abstract

In this paper we report on both the DC and low frequency noise (LFN) properties of InP/InGaAs heterojunction bipolar phototransistors (HPTs) featuring waveguide type illumination. Both DC and LFN measurements demonstrate the good quality of these devices. In particular, they exhibit a 1/f noise figure-of-merit of 2.10-8 μm2, which is exceptionally very good in the field of the compound semiconductor HBTs, where values around 10-7 μm2 are usually reported.

2000 - Low-temperature spectrally resolved cathodoluminescence study of degradation in opto-electronic and microelectronic devices [Articolo su rivista]
C., Zanotti Fregonara; G., Salviati; Borgarino, Mattia; L., Lazzarini; Fantini, Fausto
abstract

This study reports on the microcharacterization of devices for optoelectronic and for microelectronic applications using low temperature (T 5 and 77 K) spectrally resolved cathodoluminescence (SCL). The mechanisms leading to compositional inhomogeneities in the regrowth regions of InP-based butt-coupled laser-waveguide devices for semiconducting optical amplifiers (SOAs) and for defect generation in the active and cladding layers of GaAs based pump lasers for erbium-doped optical fibre amplifiers (EDFAs) were studied. Beryllium outdiffusion in the base regions of GaAs-based heterojunction bipolar transistors (HBTs) after bias ageing was also studied. By comparing the CL results with TEM, SIMS and HRXRD studies and with the existing literature, the observed growth and operation induced defects were attributed, respectively, to the following mechanisms: recombination-enhanced defect glide (REDG) in the pump lasers, recombinationenhanced impurity diffusion (REID) in the HBTs and electrostatically induced growth flux instabilities in the butt-coupled laser-waveguide devices.

2000 - Non-linear noise mechanisms in SiGe BiCMOS devices [Relazione in Atti di Convegno]
Regis, M.; Borgarino, M.; Kovacic, S.; Lafontaine, H.; Llopis, O.; Tournier, E.; Bary, L.; Plana, R.
abstract

In this paper, we have proposed some guidelines to achieve a low phase noise design using SiGe BiCMOS commercial technology. First, we observed that the excess noise is l/f type with an excess noise corner frequency in the 1 kHz range, close to the state-of-the-art. Secondly, the measurement correlation between the noise generators indicates that more than one 1/f noise source are present in these devices. We have implemented a low frequency noise model based on the intrinsic noise sources that resulted in good accuracy. Finally, the good LF noise capabilities have been confirmed by residual phase noise measurements at 10 GHz and phase noise at 4 GHz. We demonstrated that an appropriate intrinsic LF noise modelling gives quite a good phase noise prediction. This provides the opportunity of performing low phase noise design of RF and microwave oscillators.

2000 - On the effects of hot carriers on the RF characteristics of Si/SiGe heterojunction bipolar transistors [Articolo su rivista]
Borgarino, Mattia; J. G., Tartarin; J., Kuchenbecker; T., Parra; H., Lafontaine; H., Kovacic; R., Plana; J., Graffeuil
abstract

This work for the first time experimentally investigates the hot carrier effects on the RF characteristics (up to 30 GHz) of Si/SiGe heterojunction bipolar transistors (HBT's). Reverse base-emitter voltage stresses were applied at room temperature on BiCMOS compatible, sub-micron transistors. The main observed degradation is a decrease of S 21. It was found that this degradation is minimized (maximized) when biasing at constant collector (base) current. These results may be valuable indications also for degradations induced by ionizing radiations.

2000 - SiGe bipolar technologies for low phase noise RF and microwave applications [Relazione in Atti di Convegno]
Regis, M.; Borgarino, M.; Bary, L.; Llopis, O.; Graffeuil, J.; Gruhle, A.; Kovacic, S.; Plana, R.
abstract

This paper presents an overview of the low frequency noise performances of both 'abrupt' and 'gradual' SiGe HBTs. We demonstrated that when appropriate device is used, 1/f corner noise frequency in the 1 kHz is obtained. We further presented a correlation with phase noise performances which outperform those reported with III-V devices.

2000 - SiGe bipolar technologies for low phase noise RF and microwave applications (invited) [Relazione in Atti di Convegno]
Regis, M.; Borgarino, M.; Bary, L.; Llopis, O.; Graffeuil, J.; Gruhle, A.; Kovacic, S.; Plana, R.
abstract

This paper presents an overview of the low frequency noise performances of both 'abrupt' and 'gradual' SiGe HBTs. We demonstrated that when appropriate device is used, 1/f corner noise frequency in the 1 kHz is obtained. We further presented a correlation with phase noise performances which outperform those reported with III-V devices.

2000 - SiGe technologies for the new information society [Relazione in Atti di Convegno]
Regis, M.; Bary, L.; Coustou, A.; Sadowy, J.; Tournier, E.; Borgarino, M.; Llopis, O.; Grafeuil, J.; Plana, R.
abstract

This paper presents an overview on the SiGe technology that could be used to design the future communications systems. Both bipolar and unipolar technology are available. Nevertheless bipolar technology are very successful in term of noise, linearity power and reliability and they will outperform the III-V devices for applications at least up to 20 GHz.

1999 - Influence of surface recombination on the burn-in effect in microwave GaInP/GaAs HBT's [Articolo su rivista]
Borgarino, Mattia; R., Plana; S. L., Delage; Fantini, Fausto; J., Graffeuil
abstract

In this paper, we report on the early increase of the de current gain (burn-in effect) due to the electrical stress of carbon doped GaInP/GaAs heterojunction bipolar transistors (HBT's). Devices featuring different passivation layers, base doping, and emitter widths were investigated. The obtained data demonstrate that the burn-in effect is due to a reduction of the surface recombination located at the extrinsic base surface, around the emitter perimeter. It is concluded that the recombination centers are related to defects at the passivation/semiconductor interface and that, during the stress, they are passivated by hydrogen atoms released from C-H complexes.

1999 - Investigation of the burn-in effect in microwave GaInP/GaAs HBTs by means of numerical simulations [Relazione in Atti di Convegno]
A., Rusani; J., Kuchenbecker; Borgarino, Mattia; R., Plana; J., Graffeuil; M., Vanzi
abstract

The GaInP/GaAs HBTs demonstrate outstadning long-term reliability performance. Nevrtheless they still suffer from a short-term DC current gain instability, known as the Burn-in effect. Even if the effect is usually attributed to Hydrogen contamination passivating the Carbon atoms employed as base dopant, the underlying physical mechanism is still unclear.The present work addresses the Burn-in effect by means of numerical simulations performed with the device simulation software BLAZE by Silvaco. The rsults give support to the hypothesis that the Burn-in effect is a surface related phenomenon. The simulations reveal that a fixed surface charge located near the edge of the emitter mesa should be introduced. The work points out also that simultaneous variations of both this charge and of the surface recombination velocity should be taken into account. This simulation approach could be a useful tool, in order to develop a chemical/physical model of the Burn-in effect.

1999 - Low Noise Considerations in SiGe BiCMOS Technology for RF Applications [Relazione in Atti di Convegno]
Borgarino, Mattia; S., Kovacic; H., Lafontaine; Z. F., Zhou; R., Plana
abstract

This paperfocuses on the noise trends that must be characterized in order to design low-noise, low-cost RF circuits in a commercial SiGe BiCMOS technology. We present low frequency noise and high frequency behavior associated with this technology and the design of a broad band active balun, which has been optimized with respect to the noise and the phase drift.

1999 - Noise properties in SiGe BiCMOS devices [Relazione in Atti di Convegno]
J. G., Tartarin; R., Plana; Borgarino, Mattia; H., Lafontaine; M., Regis; O., Llopis; S., Kovacic
abstract

This paper deals with the investigation of the noise properties of a commercially available SiGe BiCMOS technology. We present some results related with the high frequency noise behavior of these devices and we defined some geometrical rules allowing the design of low noise amplifier. Concerning their low frequency noise performances, the devices exhibit 1/f noise source with an excess corner noise frequency in the 1 kHz range which is close to the state of the art for a monolithic technology. We further developed a scaleable non linear low frequency noise model implementable in a commercial microwave software. Finally, additional residual phase noise measurements confirmed the impressive capabilities of SiGe HBT technology for low noise RF applications

1999 - On the correlation between drain-gate breakdown voltage and hot-electron reliability in InP HEMT's [Articolo su rivista]
Menozzi, R.; Borgarino, M.; Van Der Zanden, K.; Schreurs, D.
abstract

By comparing devices with different recess widths, we show that the off-state drain-gate breakdown voltage (BVDG) may give totally misleading indications on the reliability of lattice-matched InP HEMT's under hot-electron (HE) and impact ionization conditions, from both standpoints of gradual and catastrophic degradation. Since the hot-electron degradation effects observed in our HEMT's are quite common, we believe that our results should be considered as a general caveat whenever indications on HE HEMT robustness are inferred from BVDG measurements.

1999 - On the short and long term degradation of GaInP/GaAs heterojunction bipolar transistors [Articolo su rivista]
Borgarino, Mattia; R., Plana; S., Delage; Fantini, Fausto; J., Graffeuil
abstract

This work deals with the short and long term effects of a current stress performed at room temperature on Carbon doped GaInP/GaAs heterojunction bipolar transistors, The investigation has been carried out by means of DC characterizations and low frequency noise (LFN) measurements in the 250 Hz-100 kHz frequency range. During the stress the devices were biased in the forward active region, a collector-emitter voltage of 7.7 V and a collector current density of 2.2 x 10(4) A/cm(2) were imposed. The effect of the stress on the DC and LFN characteristics were compared and discussed in terms of two recombination mechanisms, The discussion points out that both extrinsic and intrinsic recombination processes have to be taken into account in order to justify the short and long term effects of the electrical stress. (C) 1999 Elsevier Science Ltd. All rights reserved.

1999 - Propriétés electriques des transistors bipolaires à hétérojonction sur InP pour des applications optoélectroniques monolithiques [Relazione in Atti di Convegno]
Borgarino, Mattia; R., Plana; M., Fendler; J. P., Vilcot; F., Mollot; J., Barette; D., Decoster; J., Graffeuil
abstract

Les transistors bipolaires à hètèrojonction (TBHs) sur substrat InP sont des composants trés prometteurs pour la fabrication des circuits rapides à bas niveau de puissance dissipée. Ils trouvent des appliactions très attractives dans le domaine de l'optoélectronique integrée monolithique. Les résultats présentés dans ce travail démontrent que des InP/InGaAs opto-TBH de type guide d'onde, peuvent etre fabriqués avec un comportement preque idéal et un niveau du bruit aux basse fréquence très rèduit.

1999 - Reliability issues in compound semiconductor heterojunction devices [Relazione in Atti di Convegno]
Fantini, Fausto; Borgarino, Mattia; L., Cattani; P., Cova; R., Menozzi; G., Salviati; C., Canali; G., Meneghesso; E., Zanoni
abstract

The failure mechanisms affecting electron devices based on compound semiconductors are reviewed.

1999 - Reliability testing of InP HEMT's using electrical stress methods [Articolo su rivista]
Van Zanden, K. D.; Schreurs, D. M. M. -P.; Menozzi, R.; Borgarino, M.
abstract

In this paper, we discuss the results of three different electrical stress tests on InP-based HEMT's and their implications toward reliability. These are hot electron (HE) stress, transmission line pulse (TLP) measurements, and RF overdrive stress. Some processing parameters have been varied to investigate their influence on reliability issues. HE stress is performed on a set of Si3N4 passivated devices with increasing recess width. Degradation is observed to be largely dependent on recess width, due to changes at the InAlAs-Si3N4 interface. With TLP measurements, an ESD-like reliability study is performed on devices with different types of Schottky barriers. Although epilayers with In0.40Al0.60 as Schottky material show improved breakdown and leakage characteristics over In0.52Al0.48As, pulsed stress tests reveal an earlier breakdown. Finally, the degradation under large-signal RF overdrive stress is determined with a nonlinear network measurement system (NNMS). Both on- and off-state degradation are studied with this set-up. Results appeared to be strongly dependent on the phase difference between the stress voltage waves applied at the device ports.

1998 - A comparison between HBt small-signal model optimization using a genetic algorithm and direct parametric extraction [Relazione in Atti di Convegno]
Borgarino, Mattia; R., Menozzi; J., Tasselli; A., Marty
abstract

This work for the first time shows that physically meaningful, wideband, multi-bias small-signal modeling of HBTs can be efficiently and accurately achieved using a genetic Algorithm (GA). The physical significance of the equivalent circuit parameters extracted by the GA was checked using a Direct Extraction Technique (DET). The two procedures were applied to HBT S-parameters measured at different bias points. The simulated S-parameters match very well with the measured ones over the whole frequency range investigated. For each point we obtained quite a good agreement between the parameters extracted by the DET and by the GA, which demonstartes the ability of the GA to efficiently extract a physically significant HBT small-signal model.

1998 - Cathodoluminescence evidence of stress-induced outdiffusion of beryllium in AlGaAs/GaAs heterojunction bipolar transistors [Articolo su rivista]
Borgarino, Mattia; G., Salviati; L., Cattani; L., Lazzarini; C., Zanotti Fregonara; Fantini, Fausto; A., Carnera
abstract

Cathodoluminescence spectroscopy has been used for the first time in order to detect the base-dopant outdiffusion induced by current stress in AlGAs/GaAs Be-doped heterojunction bipolar transistors. The results show that diffusion of base dopant along the growth direction of the HBT structure occurs during the stress and this conclusion is confirmed by SIMS analysis. Integrated CL intensity variations induced by the stress suggest that the mechanism of recombination-enhanced impurity diffusion is responsible for diffusion of Be.

1998 - Correlation between burn-in effect and emitter orientation in GaInP/GaAs HBTs [Relazione in Atti di Convegno]
Borgarino, M.; Plana, R.; Tartarin, J. G.; Graffeuil, J.; Fantini, F.; Delage, S.
abstract

The burn-in f!ffict has been studied in C and IniC doped GaInPIGaAs HETs jeaturing [OllJ and [011] emitter orientations. The investigation has been carried out by means of DC, and Low Frequency Noise (LFN) (250Hz-100kHz) characterizations. We found that the [011] emitter orientation minimizes the burn-in effect.

1998 - Early Variations of the Base Current in In/C-doped GaInP/GaAs HBT's [Relazione in Atti di Convegno]
Borgarino, Mattia; R., Plana; S., Delage; H., Blank; Fantini, Fausto; J., Graffeuil
abstract

This paper reports on the early variations of the base current (burn-in effect) in SiN passivated, double-mesa processed, In/C-doped GaInP/GaAs HBT's induced by stressing the devices at room temperature and under different bias conditions

1998 - Experimental evaluation of the minimum detectable outdiffusion length for AlGaAs/GaAs HBTs [Articolo su rivista]
Borgarino, Mattia; C., Voltolini; Fantini, Fausto; J., Tasselli; A., Marty
abstract

Triple mesa, Be-doped AlGaAs/GaAs HBTs were stressed at low temperature by forcing an emitter current density while the devices were biased in the forward active region. The effect on the d.c. characteristics was investigated and the results demonstrated that a base dopant outdiffusion is the degradation mechanism.By merging the experimental data with numerical simulations we obtained for the first time an experimental evaluation of the minimum detectable outdiffusion length. The measured value is in fair agreement with the theoretical value reported in the literature.

1998 - HBT small-signal model extraction using a genetic algorithm [Relazione in Atti di Convegno]
R., Menozzi; Borgarino, Mattia; J., Tasselli; A., Marty
abstract

This work shows that physically meaningful wideband, multi-bias small-signal modeling of HBTs can be efficiently and accurately achieved using a genetic algorithm (GA). The physical significance of the equivalent circuit parameters extracted by the GA is checked using a direct extraction technique (DET). For each point we obtained a good agreement between the parameters extracted by the DET and by the GA, which demonstrates the ability of the GA to efficiently extract a physically significant small-signal model.

1998 - Hot electron degradation of the DC and RF characteristics of AlGaAs/InGaAs/GaAs PHEMT’s. [Articolo su rivista]
Borgarino, Mattia; R., Menozzi; Y., Baeyens; P., Cova; Fantini, Fausto
abstract

This paper reports on hot electron (HE) degradation of 0.25-μm Al0.25Ga0.75As/In0.2Ga0.8 As/GaAs PHEMT's by showing the effects of the hot electron stress on both the dc and rf characteristics. The changes of dc and rf behavior after stress turn out to be strongly correlated. Both can be attributed to a decrease of the threshold voltage yielding different effects on the device gain depending on the bias point chosen for device operation and on the bias circuit adopted: a fixed current bias scheme will minimize the changes induced by the stress. The work also presents a study of the dependence of device degradation on the stress bias condition.

1998 - Pulsed current stress of Berillium doped AlGaAs/GaAs HBTs [Articolo su rivista]
L., Cattani; Borgarino, Mattia; Fantini, Fausto
abstract

The major concern for reliability of Berillium doped HBTs is the diffusion of the base dopant towards the emitter. This degradation can be enhanced by the device self-heating and/or by REID mechanism. In order to separate the thermal and REID components to the Berillium outdiffusion we performed a pulsed current stress on AlGaAs/GaAs HBTs. In this paper we report on results obtained with different values of the duty cycles for this current.

1998 - Reliability of Gaas-based HBTs [Relazione in Atti di Convegno]
Fantini, Fausto; Borgarino, Mattia; L., Cattani; R., Menozzi
abstract

Most of the applications of the Heterojunction Bipolar Transistors (HBTs) are in the field of telecommunications, where device reliability is a key issue. This work reports on a major HBT reliability issue: base dopant stability. In particualr, the most two widely employed base dopnats are addressed: Beryllium and Carbon. The instability phenomena typical of each doping impurity, and their effects on the HBT cahracteristics are briefly overviewed in this paper.

1998 - Study of degradation mechanisms in compound semiconductor based devices by SEM-cathodoluminescence [Articolo su rivista]
Salviati, G.; Zanotti-Fregonara, C.; Borgarino, M.; Lazzarini, L.; Cattani, L.; Cova, P.; Mazzer, M.
abstract

This papers reports on the microcharacterization of devices for optoelectronic and high-speed electronic applications by spectrally resolved cathodoluminescence. The advantages offered by the high lateral resolution, monochromatic imaging and depth resolved spectral analysis of the technique are presented. In particular, InP based semiconducting optical amplifiers and GaAs based pump lasers for optical fiber communications are characterized from the point of view of compositional inhomogeneities and defect generation in the active regions. GaAs based heterqjunction bipolar transistors and high electron mobility transitors are studied to respectively reveal Be outdiffusion from the base and break down walkout after bias aging. GaAs based solar cells are also investigated to show the correlation between dislocations and impurity gettering. Finally the limits of the technique are briefly discussed. © 1998 Elsevier Science Ltd. All rights reserved.

1998 - The influence of the emitter orientation on the DC and low frequency noise characteristics of GaInP/GaAs HBTs [Relazione in Atti di Convegno]
Borgarino, Mattia; J. G., Tartarin; R., Plana; S., Delage; J., Graffeuil; Fantini, Fausto
abstract

The present paper focuses on the influence of the emitter orientation on the electrical characteristics of GaInP/GaAs HBTs. The investigations was carried out by means of DC and Low Frequency Noise (LFN) measurements in the 250Hz-100kHz frequency range. Samples featuring a conventional Carbon-doped base and Indium-codoped/Carbon-doped base were available. We demonstrated that the emitter orientation has an impact on the DC and LFN characteristics of HBTs. This behaviour has been attributed to piezoelectric effects and surface recombinations in the extrinsic base region around the emitter perimeter.

1997 - Cathodoluminescence investigation of stress-induced Berillium outdiffusion in AlGaAs/GaAs HBTs [Relazione in Atti di Convegno]
Cattani, Laura; Salviati, Giancarlo; Borgarino, Mattia; Menozzi, Roberto; Fantini, Fausto; Lazzarini, Laura; Fregonara Carlo, Zanotti
abstract

In this study Cathodoluminescence spectroscopy has been used for the first time in order to detect the base dopant outdiffusion induced by current stress in AlGaAs/GaAs Be-doped HBTs. The results evidence a base dopant diffusion along the growth direction of the HBT structure and suggest that the REID mechanism can be responsible of that. Therefore Cathodoluminescence can be used as a non destructive technique to study Berillium outdiffusion.

1997 - Correlation between the burn-in effect and the extrinsic base surface quality in C-doped GaInP/GaAs HBTs [Relazione in Atti di Convegno]
Borgarino, M.; Tartarin, J. G.; Delage, S.; Plana, R.; Fantini, F.; Graffeuil, J.
abstract

The present work compares two sets of Carbon doped GaInP/GaAs HBTs. The only difference between the device sets resides in the technology employed to passivate the extrinsic base surface region. The results demonstrate that the burn-in effect is a surface related phenomenon and that the ledge passivation technology is very promising to improve device reliability.

1997 - Effect of passivation on the hot electron degradation of lattice-matched InAlAs/InGaAs/InP HEMTs [Relazione in Atti di Convegno]
Menozzi, R.; Borgarino, M.; Baeyens, Y.; van der Zanden, K.; Van Hove, M.; Fantini, F.
abstract

Passivated devices show a permanent decrease of drain current and transconductance at high gate bias. The degradation is attributed to negative charge accumulation at the surface leading to cap depletion, and tends to be weaker in selectively etched gate devices, where the cap is laterally etched away much more. This dc effect is mirrored by a reduction of the current gain cutoff frequency in the same bias range. Some devices experience as a consequence of the stress, a permanent threshold voltage increase and a transconductance compression similar to that of the passivated samples. Others show a temporary reduction of the threshold voltage resulting in an increase of the drain current for fixed gate and drain bias.

1997 - Electrical and thermal simulation of local effects for electromigration [Articolo su rivista]
Borgarino, Mattia; V., Petrescu; L., Brizzolara; I., De Munari; Fantini, Fausto
abstract

The aim of this work is to investigate the distribution of the local current density and temperature gradients along the tests patterns employed for the evaluation of the electromigration phenomena in metal tracks.

1997 - On the effects of hot electrons on the DC and RF characteristics of lattice-matched InAlAs/InGaAs/InP HEMT's [Articolo su rivista]
R., Menozzi; Borgarino, Mattia; Y., Baeyens; M., Van Hove; Fantini, Fausto
abstract

The authors for the first time present results of hot electron stressing of InAlAs/InGaAs/InP high electron mobility transistors (HEMTs). High drain bias, room temperature stress cycles have been applied to 0.3 μm, SiN-passivated, lattice-matched devices, and the changes of the DC and RF (up to 50 GHz) characteristics have been studied. Both the DC and RF device gain degrade after stressing; the effect of the stress on the unity current gain cutoff frequency fT is studied under different bias conditions. Results indicate that surface degradation may be responsible for the observed changes

1997 - Study of the DC and RF degradation of Be-doped AlGaAs/GaAs HBTs under constant current stress [Relazione in Atti di Convegno]
Borgarino, M.; Menozzi, R.; Tasselli, J.; Marty, A.; Fantini, F.
abstract

AlGaAs/GaAs HBTs play a significant role in the market of wireless products. Using HBT devices fabricated at LAAS and tested on-wafer, the effects of BE diffusion on the device RF characteristics, and their correlation with the DC degradation mode are documented. The stress time and current dependences of the degradation are also resolved.

1997 - The effect of Hot Electron Stress on the DC and Microwave Characteristics of GaAs-PHEMTs and InP-HEMTs [Relazione in Atti di Convegno]
R., Menozzi; Borgarino, Mattia; P., Cova; Y., Baeyens; M., Van Hove; Fantini, Fausto
abstract

This work reports on hot electron stress experiments performed on SiN passivated AlGaAs/InGaAs/ GaAs pseudomorphic HEMTs and InAlAs/InGaAs/InP lattice-matched HEMTs.

1997 - The effect of the base dopant concentration on the stability of Be-doped AlGaAs/GaAs HBTs devices [Articolo su rivista]
Borgarino, Mattia; R., Losi; Fantini, Fausto; M., Schussler; H. L., Hartnagel; S., Franchi; A., Bosacchi
abstract

The impact of the base dopant lavel on the stability of Be-doped AlGaAs/GaAs HBTs is investigated by means of forward current stress carried out at room temperature. The results show that the degradation mechanism is due to the Beryllium outdiffusion: the higher is the base dopant concentration, the larger the degradation.

1996 - Electrical and thermal local effects simulation for electromigration [Relazione in Atti di Convegno]
Borgarino, M.; Castagnini, A.; De Munari, I.; Fantini, F.
abstract

In partictular, the thermal flux crowding effect and the conditions under which a temperature gradient peak builds up are reported. The influeilce of the bending radius of the structure is also taken into account. © 1996 Editions Frontieres.This work reports on the results obtained from numerical simulations of cturrent density, temperature and temperature gradient distributions along test strtuctures designed for the evaluation of electromigration.

1996 - Hot electron degradation of the DC and microwave performance of InAlAs/InGaAs/InP HEMTs [Relazione in Atti di Convegno]
Menozzi, R.; Borgarino, M.; Baeyeans, Y.; Van Hove, M.; Fantini, F.
abstract

This work for the first time describes the results of hot electron stress experiments performed on InAlAs/InGaAs/InP HEMTs. Both DC and RF device degradation have been studied. The main effect observed is a reduction of the DC transconductance at high gate bias; at RF this results in a decrease of current and power gain, hence of the device cutoff frequencies.

1996 - Negative Vbe shift due to base dopant outdiffusion in DHBT [Articolo su rivista]
Borgarino, Mattia; F., Paorici; Fantini, Fausto
abstract

By applying a light electrical stress at room temperature to an ALE grwon double mesa processed DHBT and comparing the experimental data with numerical simulations new interesteing results are obtained.

1996 - On the stability of the DC and RF gain of GaInP/GaAs HBTs [Relazione in Atti di Convegno]
Borgarino, M.; Plana, R.; Tartarin, J. G.; Delage, S.; Blanck, H.; Fantini, F.; Graffeuil, J.
abstract

In the present work the reliability of Carbon-doped GaInP/GaAs HBTs is evaluated by means of a current stress performed at room temperature. The impact of the stress on DC and RF characteristics and low frequency noise is reported, and a correlation between DC, RF, and noise variations is demonstrated. The effects observed are explained in terms of Carbon passivation by Hydrogen atoms released from passivation/semiconductor interface during the stress.

1996 - The effect of hot electron stress on the DC and microwave characteristics of AlGaAs/InGaAs/GaAs PHEMTS [Articolo su rivista]
R., Menozzi; Borgarino, Mattia; P., Cova; Y., Baeyens; Fantini, Fausto
abstract

The work reports on hot electron reliability of 0.25 micron Al(0.25)Ga(0.75)As/In(0.2)Ga(0.8)As/GaAs PHEMTs from the viewpoint of both DC and RF characteristics.

1995 - High base current ideality factors due to trap-assisted band-to-band tunneling in AlGaAs/GaAs HBTs [Articolo su rivista]
Borgarino, Mattia; R., Menozzi; Fantini, Fausto; M., Schussler; H. L., Hartnagel
abstract

Anomalous (>3) ideality factors in the base current of AlGaAs/GaAs HBTs, resulting in poor current gain performance, are modeled assuming a tunneling mechanism in the base-emitter space charge region assisted by centers in the forbidden gap. The model is validated by means of measurement of forward I-V characteristics as a function of temperature.