Rozprawy doktorskie na temat „Transistors HEMT”
Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych
Sprawdź 50 najlepszych rozpraw doktorskich naukowych na temat „Transistors HEMT”.
Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.
Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.
Przeglądaj rozprawy doktorskie z różnych dziedzin i twórz odpowiednie bibliografie.
Gonçalves, Cristiano Ferreira. "GaN HEMT transistors characterization for non–linear modelling". Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/21677.
Pełny tekst źródłaUltimamente, as redes de telecomunicações móveis estão a exigir cada vez maiores taxas de transferência de informação. Com este aumento, embora sejam usados códigos poderosos, também aumenta a largura de banda dos sinais a transmitir, bem como a sua frequência. A maior frequência de operação, bem como a procura por sistemas mais eficientes, tem exigido progressos no que toca aos transístores utilizados nos amplificadores de potência de radio frequência (RF), uma vez que estes são componentes dominantes no rendimento de uma estação base de telecomunicações. Com esta evolução, surgem novas tecnologias de transístores, como os GaN HEMT (do inglês, Gallium Nitride High Electron Mobility Transistor). Para conseguir prever e corrigir certos efeitos dispersivos que afetam estas novas tecnologias e para obter o amplificador mais eficiente para cada transístor usado, os projetistas de amplificadores necessitam cada vez mais de um modelo que reproduza fielmente o comportamento do dispositivo. Durante este trabalho foi desenvolvido um sistema capaz de efetuar medidas pulsadas e de elevada exatidão a transístores, para que estes não sejam afetados, durante as medidas, por fenómenos de sobreaquecimento ou outro tipo de fenómenos dispersivos mais complexos presentes em algumas tecnologias. Desta forma, será possível caracterizar estes transístores para um estado pré determinado não só de temperatura, mas de todos os fenómenos presentes. Ao longo do trabalho vai ser demostrado o projeto e a construção deste sistema, incluindo a parte de potência que será o principal foco do trabalho. Foi assim possível efetuar medidas pulsadas DC-IV e de parâmetros S (do inglês, Scattering) pulsados para vários pontos de polarização. Estas últimas foram conseguidas á custa da realização de um kit de calibração TRL. O interface gráfico com o sistema foi feito em Matlab, o que torna o sistema mais fácil de operar. Com as medidas resultantes pôde ser obtida uma primeira análise acerca da eficiência, ganho e potência máxima entregue pelo dispositivo. Mais tarde, com as mesmas medidas pôde ser obtido um modelo não linear completo do dispositivo, facilitando assim o projeto de amplificadores.
Lately, the wireless networks should feature higher data rates than ever. With this rise, although very powerful codification schemes are used, the bandwidth of the transmitted signals is rising, as well as the frequency. Not only caused by this rise in frequency, but also by the growing need for more efficient systems, major advances have been made in terms of Radio Frequency (RF) Transistors that are used in Power Amplifiers (PAs), which are dominant components in terms of the total efficiency of base stations (BSS). With this evolution, new technologies of transistors are being developed, such as the Gallium Nitride High Electron Mobility Transistor (GaN HEMT). In order to predict and correct some dispersive effects that affect these new technologies and obtain the best possible amplifier for each different transistor, the designers are relying more than ever in the models of the devices. During this work, one system capable of performing very precise pulsed measurements on RF transistors was developed, so that they are not affected, during the measurements, by self-heating or other dispersive phenomena that are present in some technologies. Using these measurements it was possible to characterize these transistors for a pre-determined state of the temperature and all the other phenomena. In this document, the design and assembly of the complete system will be analysed, with special attention to the higher power component. It will be possible to measure pulsed Direct Current Current-Voltage (DC-IV) behaviour and pulsed Scattering (S) parameters of the device for many different bias points. These latter ones were possible due to the development of one TRL calibration kit. The interface with the system is made using a graphical interface designed in Matlab, which makes it easier to use. With the resulting measurements, as a first step analysis, the maximum efficiency, gain and maximum delivered power of the device can be estimated. Later, with the same measurements, the complete non-linear model of the device can be obtained, allowing the designers to produce state-of-art RF PAs.
Grémion, Emile. "Transistor balistique quantique et HEMT bas-bruit pour la cryoélectronique inférieure à 4. 2 K". Paris 11, 2008. http://www.theses.fr/2008PA112017.
Pełny tekst źródłaNext generations of cryodetectors, widely used in physics of particles and physics of universe, will need in the future high-performance cryoelectronics less noisy and closer to the detector. Within this context, this work investigates properties of two dimensional electron gas GaAlAs/GaAs by studying two components, quantum point contact (QPC) and high electron mobility transistor (HEMT). Thanks to quantized conductance steps in QPC, we have realized a quantum ballistic transistor (voltage gain higher than 1), a new component useful for cryoelectronics thanks to its operating temperature and weak power consumption (about 1 nW). Moreover, the very low capacity of this component leads to promising performances for multiplexing low temperature bolometer dedicated to millimetric astronomy. The second study focused on HEMT with very high quality 2DEG. At 4. 2 K, a voltage gain higher than 20 can be obtained with a very low power dissipation of less than 100 μW. Under the above experimental conditions, an equivalent input voltage noise of 1. 2 nV/Hz^(1/2) at 1 kHz and 0. 12 nV/Hz^(1/2) at 100 kHz has been reached. According to the Hooge formula, these noise performances are get by increasing gate capacity estimated to 60 pF
Callet, Guillaume. "Caractérisation et modélisation de transistors HEMT AlGaN/GaN et InAlN/GaN pour l’amplification de puissance en radio-fréquences". Limoges, 2011. https://aurore.unilim.fr/theses/nxfile/default/3c0fde17-3720-49cd-9824-bd071826245e/blobholder:0/2011LIMO4033.pdf.
Pełny tekst źródłaThis report deals with the characterization of GaN HEMTs devices in order to create their model. An exhaustive characterization has been realized for AlInN/GaN and AlGaN/GAN based HEMTs. A special care has been given to the different thermal characterization methods, with the use of the 3ω method for the measurement of the thermal impedance. A study of scaling rules for small-signal model is presented. The non-linear model presented is developed in order to extend his application domain to the power amplification and power switches. Finally it is used in the design of the first poser amplifier base on AlInN technology in Ka-band
Yu, Tsung-Hsing. "Numerical studies of heterojunction transport and High Electron Mobility Transistor (HEMT) devices". Diss., Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/13035.
Pełny tekst źródłaChen, Lu. "Computerized evaluation of parameters for HEMT DC and microwave S parameter models". Ohio : Ohio University, 1995. http://www.ohiolink.edu/etd/view.cgi?ohiou1179518920.
Pełny tekst źródłaGreco, Giuseppe. "AlGaN/GaN heterostructures for enhancement mode transistors". Doctoral thesis, Università di Catania, 2013. http://hdl.handle.net/10761/1347.
Pełny tekst źródłaSadek-Hage, Chehade Sawsan. "Microcapteurs hybrides et monolithiques en technologies MESFETet HEMT : applications cinémométriques". Lille 1, 1996. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1996/50376-1996-133.pdf.
Pełny tekst źródłaKim, Hyeong Nam. "Qualitative and Quantative Characterization of Trapping Effects in AlGaN/GaN High Electron Mobility Transistors". The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1250612796.
Pełny tekst źródłaDivay, Alexis. "Etude de la fiabilité à long terme des transistors HEMT à base de GaN". Rouen, 2015. http://www.theses.fr/2015ROUES054.
Pełny tekst źródłaAlGaN/GaN HEMTs are on their way to become a reference technology for high power and high frequency applications. However, the lack of feedback regarding the reliability of such devices can be felt by the defense, automotive and telecommunications industrialists because of its lack of maturity. This study deals with the long term reliability of power AlGaN/GaN HEMTs in RADAR operating mode. It is based upon electrical characterizations, the development of an athermal measurement technique for traps and RF stresses on an ageing bench. The sum of all the characterizations before, during and after the ageing tests as well as micro-structural analyses allows to define hypotheses regarding the physical origin of the performance drift of such components
Fonder, Jean baptiste. "Analyse des mécanismes de défaillance dans les transistors de puissance radiofréquences HEMT AlGaN/GaN". Phd thesis, Université de Cergy Pontoise, 2012. http://tel.archives-ouvertes.fr/tel-00765251.
Pełny tekst źródłaFonder, Jean-Baptiste. "Analyse des mécanismes de défaillance dans les transistors de puissance radiofréquences HEMT AlGaN/GaN". Thesis, Cergy-Pontoise, 2012. http://www.theses.fr/2012CERG0576/document.
Pełny tekst źródłaAlGaN/GaN HEMTs are on the way to lead the radiofrequency power amplificationfield according to their outstanding performances. However, due to the relative youth of this technology, reliability studies in several types of operating conditions are still necessaryto understand failure mechanisms peculiar to these devices and responsible for their wearingout. This study deals with the failure analysis of power AlGaN/GaN HEMTs in RADARoperating mode (pulsed and saturated). This is based on the design of test amplifiers, theircharacterization and their stress on ageing benches. The setting up of a methodology aimingat discriminating predominant degradation modes, jointly with a micro-structural analysisof aged devices, permits to link the evolution of electrical performances with the physicalroots of these defects
ISLAM, MD SHAHRUL. "Can Asymmetry Quench Self-Heating in MOS High Electron Mobility Transistors?" OpenSIUC, 2020. https://opensiuc.lib.siu.edu/theses/2736.
Pełny tekst źródłaMrad, Mrad. "Epitaxie de couches d'alliages quaternaires à base d'InAIGaN pour les transistors de haute performance". Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALY023.
Pełny tekst źródłaCEA is dedicated to working on Atomic and Alternative Energy, to advance clean technologies using science and technology. As part of these developments, CEA-LETI is developing high power transistors and low energy LEDs with several major companies. For high power transistors, the goal is to have components working at high voltage, and passing a current of up to 100A. The properties of GaN and its alloys are particularly appropriate for these components, when compared with the more traditional transistor materials such as silicon. Currently, GaN devices typically use a heteo-structure, with an AlGaN barrier grown on GaN layers. However, due to the difference in lattice parameter between these two materials, the device performance can be limited. In order to further improve the devices, in terms of performance and reliability, we have started to develop new barrier materials based on InAlN, which has the same lattice parameter as GaN. This PhD is a continuation of these initial developments, with the intention of adapting and developing these layers for specific applications, including the growth of quaternary films composed of InGaAlN
Nouvel, Philippe. "Etude expérimentale des oscillations de plasma dans des transistors à effet de champ excitées optiquement". Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20189/document.
Pełny tekst źródłaThe terahertz range covers the electromagnetic spectrum for frequencies between 300 GHz and 30 THz. It presents a strong interest in the scientific community for several reasons: Terahertz carriers allow for high-speed free-space telecommunications; Terahertz radiations can be used for efficient and non-destructive characterization of various components and materials (minerals or organic); Terahertz detection is of major interest for astronomers as 98 % of photons emitted since the Big Bang are in this frequency domain. Unfortunately, the lack of adequate sources and detectors, i.e. room-temperature-operating, low-cost and integrated, strongly limits the use of terahertz radiations for the above-mentioned applications. A new physical phenomenon called plasma waves in nanotransistors is very promising for the realization of terahertz sources and detectors. This new phenomenon was proposed in the mid-1990s on the basis of analytical calculations, although the model was rather simplified and it did not take into account the actual experimental conditions. Recent experiments performed at low and room temperature demonstrated the feasibility to excite plasma waves in the channel of a high-electron-mobility transistor (HEMT), using a THz-radiation excitation.This work presents a different way to excite this plasma wave by using an optical beating excitation. A systematic study of nanometric transistors under optical excitation to better understand and exploit plasma waves is carried on. The effects of geometrical parameters such as transistor gate length or cap-layer length are investigated. The dependence of the plasma waves on different electrical parameters such as drain voltage and gate voltage is also presented. Along with this experimental work, a pseudo-two-dimensional hydrodynamic simulator was developed to analyze the physical processes in the transistors on a more rigorous theoretical basis than the simplified analytical model. As a result of this joint experimental and theoretical investigation, we achieved a better understanding and an accurate description of the complex mechanism of plasma waves excited in field-effect transistors. Finally, we propose new structures to be used, from one hand, as a monochromatic terahertz source based on a HEMT excited by an optical beating, and,from the other hand, a spectrally-resolved heterodyne detector based on the mixing between the terahertz radiation to be analyzed and an optical beating used as a tunable local oscillator
Seo, Sanghyun. "GaN-based heterostructure field effect transistors and MMICs for high frequency applications". Aachen Shaker, 2009. http://d-nb.info/999595059/04.
Pełny tekst źródłaYi, Congwen. "Reliability study of enhancement-mode AIGaN/GaN HEMT fabricated with fluorine plasma treatment technology /". View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?ECED%202008%20YI.
Pełny tekst źródłaHamady, Saleem. "Nouveaux concepts de transistors de puissance à haute mobilité électronique (HEMT) en nitrure de gallium (GaN)". Toulouse 3, 2014. http://thesesups.ups-tlse.fr/2635/.
Pełny tekst źródłaAlGaN/GaN HEMTs are very promising candidates for high frequency applications with high power and low noise. While switching applications strongly demand normally-off operation, conventional HEMTs attain a channel populated with electrons at zero gate voltage making them normally-on. For the sake of achieving normally-off HEMTs, several structures have been proposed such as recessed gate structures, fluorine ion treatment, pn junction gate structures, thin AlGaN barrier and Gate Injection transistor. The effectiveness of the agent used to obtain normally-off, whether it is recessing the gate, introducing a cap layer or implanting fluorine, increases as the agent comes closer to the AlGaN/GaN interface. Unfortunately, when introducing a cap layer or recessing the gate, coming closer to the interface means decreasing the barrier thickness, which strongly affects the density of the 2DEG. In the case of fluorine implantation, getting closer will increase the probability of fluorine ions getting into the channel and hence degrade the mobility of the 2DEG. In this work we propose two new concepts to achieve normally-off operation. We suggest the introduction of negative fluorine ions on one hand or a p-GaN region on the other hand, below the channel, under the AlGaN/GaN interface and away from high current density regions. After calibrating the simulator using experimental results from a normally-on HEMT device, we have shown that our proposed structures are more effective: the concentration required to achieve normally-off operation is lower than in the other existing solutions and the confinement of the two dimensional electron gas below the gate is better. The proposed ideas were also applied to Metal Insulator Semiconductor HEMT (MIS-HEMT) and Gate Injection Transistor (GIT), giving rise to a normally-off HEMT with high controllable threshold voltage
PALLA, RAMIRO. "Etude et realisation de transistors hemt alinas/gainas/inp pour circuits opto-electroniques a hauts debits". Paris 6, 1995. http://www.theses.fr/1995PA066684.
Pełny tekst źródłaCozette, Flavien. "Mesure de la température de transistors de type HEMT AlGaN/GaN en régime de fonctionnement hyperfréquence". Thesis, Lille 1, 2018. http://www.theses.fr/2018LIL1I074/document.
Pełny tekst źródłaPower microwave devices development is a challenge which leads to improve radars, spatial or telecommunications systems. AlGaN/GaN HEMTs have demonstrated their capabilities to be used in such systems. However, systems performances improvement leads to miniaturize size of transistors. Consequently, the transistors operating temperature increases. As a result, thermal management is very important. A high device operating temperature will deteriorate device performances and device reliability. Several methods such as the use of diamond substrate or the integration of micro-channel lead to improve component thermal dissipation. It has been highlighted that the proper thermal management of the transistor thermal behavior is necessary to obtain performant and reliable systems. In order to improve devices thermal management, transistors’ operating temperature must be determined accurately in real time. The thesis goal consists in developing a method to measure in real time AlGaN/GaN HEMT operating temperature under microwave power condition. This method will permit to study component reliability, to control device operating temperature and to assure systems preventive maintenance purpose. According to the literature, several methods are used to determine HEMT operating temperature. However, these methods cannot be employed to determined packaged components operating temperature. To solve this problem, the proposed method in this work consists in integrating a resistive temperature sensor in the HEMT active area. A design has been developed which permits to integrate a sensor in components for microwave power applications above that 10 GHz. An important part of the thesis work consisted in fabricating the devices (transistors and sensors) in clean room. After fabrication thermal characterizations have been performed under microwave power conditions
Maher, Hassan. "Transistors à effet de champ sur substrat InP à canaux composites : Structure, technologie et caractérisation". Paris 11, 1999. http://www.theses.fr/1999PA112412.
Pełny tekst źródłaThis thesis deals with composite channel InP HEMT devices in which a high mobility channel is used on top of a second channel characterized by a low impact ionization rate. Such structures are aiming at an improvement of the breakdown characteristics of InP HEMTs, while retaining their excellent high frequency properties. A first part is devoted to the device structure design, using numerical modeling tools; a 3-channel structure with a [delta]-doped quaternary layer sitting in the middle of the InGaAs/InP channel, has been identified as very promising. Improvements in the technological processes used for conventional HEMT structures are then presented, as required by the specific features of the structure. In particular optimizations have been carried out with respect to ohmic contacts, gate recess and Schottky contact. Fabricated devices have exhibited quite high cut-off frequency (Ft = 265 GHz at 0. 1 [mu]m gate length), and very good breakdown voltage characteristics (> 20 V and 4 V in pinched-off and open channel conditions respectively). In order to assess the possible degradation in breakdown voltage and high frequency voltage gain brought by the output conductance, an analysis of the excess gate current has been carried out. Two bumps in the gate current vs gate voltage characteristics are observed at moderate drain voltage. Analysis of these bumps vs temperature, gate-drain spacing and gate length shows that the bump observed in open channel conditions is associated to impact ionization in the channel, while the second bump, observed close to pinch-off, is attributable to electrons real space transfer from the channel to the buffer - substrate interface
Brosteaux, Christophe. "Etude de multiplicateurs de fréquence à HEMT : application à un tripleur 10-30 GHz". Lille 1, 1997. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1997/50376-1997-33.pdf.
Pełny tekst źródłaAltuntas, Philippe. "Fabrication et caractérisation de dispositifs de type HEMT de la filière GaN pour des applications de puissance hyperfréquence". Thesis, Lille 1, 2015. http://www.theses.fr/2015LIL10131/document.
Pełny tekst źródłaGallium Nitride (GaN) based High Electron Mobility Transistors (HEMTs) have emerged as the best candidate for high temperature, high voltage and high power operation in millimeter-wave range. The unique combination of high breakdown field, high electron velocity, and large sheet electron densities of III-N material permits outstanding performance. The work was performed within IEMN laboratory in Microwave Power Devices group. It relates the fabrication and the characterization of GaN HEMT devices for microwave power applications. The first part exposes the physical and electrical properties of gallium nitride as well as a review concerning the state of the art in terms of output power density related to GaN HEMTs. The second chapter deals with the technological processes with a particular attention on the process optimization regarding the ohmic contact and the T-gate technology. Despite outstanding properties, the HEMT performance remains inherently limited by physical and electrical parasitic phenomena. Thus, the third chapter presents the whole studies performed in other to understand these limitation effects (losses, traps, thermal effect). In the last chapter DC, RF, pulsed and large signal measurements are reported for HEMTs based on different heterostructures. In particular, the capability of AlGaN/GaN transistors on Si(111) substrate grown by MBE is demonstrated for high frequency microwave power applications at 40GHz with a continuous wave output power density of 2.7W/mm associated with a power added efficiency of 12.5% and a linear gain of 6.5dB corresponding to the highest saturated power density ever reported on Si(111) substrate to date
Wang, Ruonan. "Enhancement/depletion-mode HEMT technology for III-nitride mixed-signal and RF applications /". View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?ECED%202008%20WANG.
Pełny tekst źródłaBadirou, Mohamed Rilwanowlai. "Simulation Monte-Carlo en régimes statique et dynamique de HEMT de la filière InP". Lille 1, 1998. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1998/50376-1998-235.pdf.
Pełny tekst źródłaLe, Coustre Gwenael. "Contribution au développement d’une filière de transistor de forte puissance à base de technologie HEMT GaN pour applications télécoms et radar". Thesis, Lille 1, 2009. http://www.theses.fr/2009LIL10118/document.
Pełny tekst źródłaThe use of wide-gap materials is a solution for the generation of power at microwaves frequencies, and HEMTs processed on Gallium Nitride currently present the best world performances in this domain. However, the designers need to know their electrical limitations. More precisely, they need to know their electric characteristics in their areas of operation, and also to have at their disposal mathematical model for CAD tools. In a first part, electrical characterizations were carried out in order to determine the impact of the physical limitations on the generation of power: breakdown voltage, gate-lag and drain-lag related trapping effects, thermal resistance of interface in the epitaxy…In the second part of this thesis, the design and the realization of first demonstrators were carried out in band S (3 GHz). These demonstrators allow a first characterization of the power devices with several millimeters of gate development processed in the laboratory. These characterizations are not to be done on wafer, for thermal reasons as well as electrical connections issues. They allow determining the optimum impedances for power and/or PAE very close to the DUT terminals, i.e. with a good precision. These impedances will be used for the design of the amplifiers, presented in the first part. First, an analysis of the impact of the input and output loads on the reachable bandwidth has been done. Secondly, a presentation of the design and the characterization of 25W and 100W class HPA is presented. The measurements of these latter amplifiers have shown output power higher than 120W, with a power added efficiency and an associated power gain respectively of 40% and 22 dB. These results, in terms of power, PAE and temperature, make us very confident for the future design of GaN HEMTs based amplifiers in S-band for radar applications
Malela-Massamba, Ephrem. "Développement et caractérisation de modules Technologiques sur semiconducteur GaN : application à la réalisation de cathodes froides et de transistor HEMT AlGaN/GAN". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1078.
Pełny tekst źródłaThe results presented in this manuscript relate to technological developments and device processing on wide bandgap III-N semiconductor materials. They have been focused on III-N HEMT transistors and GaN cold cathodes. They have been realised within the III-V lab, which is a common entity between: Alcatel - Thales - CEA Leti. They have been financially supported by Thales Electron Devices company (TED) and the French National Research Agency ( ANR ). Regarding III-N HEMTs, our investigations have been focused on the development of device gate processing, which includes : the structuration of gate electrodes, the study of device passivation, and the realization of Metal-Insulator-Semiconductor High Mobility Electron Transistors ( MIS-HEMTs ). The “ Normally-off ” MOS-HEMT structures we have realized exhibit performances comparable to the state of the art, with a maximum drain current density between 270 and 400 mA / mm, a ION / IOFF ratio > 1.100, and a breakdown voltage > 200V. The threshold voltage values range between + 1,8 V and + 4V. We have also been able to demonstrate prototype GaN cold cathodes providing a maximum current density of 300 µA / cm2, emitted in vacuum for a bias voltage around 40 V
Echeverri, Duarte Andres. "Etude de la Fiabilité des Transistors HEMTs AIGaN/GaN de puissance en condition opérationnelle". Thesis, Normandie, 2018. http://www.theses.fr/2018NORMR014.
Pełny tekst źródłaThis PhD Thesis is about the reliability of enhancement Gallium Nitride high electron mobility power transistors, recently on the market. This work is focused on physics of failure analysis on aged devices under real mission switching profiles. A novel stress bench able of stablish real operating conditions on a transistor without using a load, so minimizing energy consumption. Also, the circuit has two additional devices that undergo separate current and voltage stresses and are used for better understanding of degradations on main device under test. Electric characterization of aged devices allows determination of failure modes. Decapsulation and sample preparation procedures at different scales were developed to access the active zone of the devices and perform micro-structural analyses by the means of spectral photoemission, scanning and transmission electronic microscopies. Then, failure mechanisms are correlated with the corresponding modes
Drouot, Virginie. "Elaboration par épitaxie par jets moléculaires et caractérisation d'hétérostructures pseudomorphiques Ga1-xInxAs/AlInAs sur InP pour transistors à haute mobilité d'électron (HEMT)". Ecully, Ecole centrale de Lyon, 1993. http://www.theses.fr/1993ECDL0035.
Pełny tekst źródłaHédoire, Jérôme. "Simulation hydrodynamique bidimensionnelle de transistors de type HEMT pseudomorphique : analyse physique et optimisation pour l'amplification de puissance hyperfréquence". Lille 1, 1997. http://www.theses.fr/1997LIL10224.
Pełny tekst źródłaBourcier, Eric. "Analyse de fonctionnement en amplification de puissance en bande Ka des transistors HEMT des filières AsGa et InP". Lille 1, 1998. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1998/50376-1998-9.pdf.
Pełny tekst źródłaAupetit-Berthelemot, Christelle. "Etude des effets parasites du transistor à haute mobilité électronique (HEMT) sur InP pour applications micro-optoélectroniques". Limoges, 1998. http://www.theses.fr/1998LIMO0042.
Pełny tekst źródłaElharizi, Malika. "Contribution à l’étude des modes de dégradation des transistors HEMT à base de GaN pour les applications de puissance". Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLN040/document.
Pełny tekst źródłaPower components based on GaN are known by the instability of their electrical characteristics, in particular the threshold voltage and the on-state resistance. This is due to the effects of trapping/de-trapping mechanisms in the structure. The work presented in this memoir consists of two main parts. At the first step, we highlight the effect of a number of switching parameters on the evolution of the dynamic resistance with successive switching cycles. In particular, we analyze the effect of blocking voltage, switching frequency and temperature on the evolution of dynamic resistance. In a second step, we present the results of power cycling tests performed using 80K of junction temperature swing on Normally-ON Al2O3/AlGaN/GaN MOS-HEMTs. Then, we perform trap characterizations, based on the analyses of transient current measurements, during the aging process. The results show that irreversible degradation affects threshold voltage with drift to negative values. These drifts were mainly attributed to cumulative trapping with power cycles, probably induced by hot electrons, in a progressive and non-recoverable way
El, Rafei Abdelkader. "Analyse des effets dispersifs dans les transistors radiofréquences par mesures électriques". Limoges, 2011. https://aurore.unilim.fr/theses/nxfile/default/381740cc-fba9-4386-9b9d-0e0dd1113527/blobholder:0/2011LIMO4037.pdf.
Pełny tekst źródłaPower amplifiers (PAs) are key elements of telecommunications and radar front ends at radio frequencies. The potential of the PA is limited by the phenomena of dispersion. In this context, we are interested in the characterization of thermal phenomena in the HBT transistors of different technology (GaAs, InP and SiGe) and characterization of thermal and traps effects in HEMT transistors based on GaN (AlGaN and AlInN) at low frequencies. A bench for low frequency S-parameters measurement [10 Hz, 40 GHz] is set up to enable us to study the behavior of the new components in the frequency range seat of nonlinear parasitic phenomena. A simple, yet accurate, method to experimentally characterize the thermal impedance of Hetero junction Bipolar Transistors (HBT) with different technologies proposed. This method relies on low frequency S-parameters measurements. A detailed study has been initiated to characterize the phenomena of low frequency dispersion in the HEMT transistors based on GaN. The thermal and traps effects are studied for both technologies (AlGaN/GaN and AlInN/GaN) with the method of admittance spectroscopy to quantify the levels of deep traps
Dessenne, François. "Etude théorique et optimisation de transistors à effet de champ de la filière InP et de la filière GaN". Lille 1, 1998. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1998/50376-1998-19.pdf.
Pełny tekst źródłaLayati, Bouchta. "Croissance par épitaxie par jets moléculaires d'hétérostructures AlInAs/Ga1-xInxAs/InP à dopage planaire pour application aux transistors HEMT". Lille 1, 1996. http://www.theses.fr/1996LIL10167.
Pełny tekst źródłaHerbecq, Nicolas. "Conception et réalisation de composants GaN innovants pour les applications de conversion de puissance au-delà du kilovolt". Thesis, Lille 1, 2015. http://www.theses.fr/2015LIL10152.
Pełny tekst źródłaGaN-based High Electron Mobility Transistors (HEMTs) on Silicon substrate (GaN-on-Si) are promising candidates for future generations of power converters. Today, technical limitations need to be overcome in order to allow the industrial commercialization of this technology, particularly for high-voltage applications (≥ 600 V). In this frame, this work constitutes a contribution to the development of innovative GaN-on-Si devices operating above 1kV. We mainly focused on the improvement of the blocking voltage of the transistors with the realization of a local substrate removal process with the aim of suppressing the parasitic conduction phenomena between the buffer layer and the substrate. Owing to an improved technological process and innovative epitaxial structures, we observed a drastic improvement of the electrical performances of the transistor under high voltages. In particular, we have been able to demonstrate for the first time a blocking voltage above 3kV for this emerging technology. These results, well beyond the state of the art, pave the way for higher voltage operation GaN-on-Si power devices
Abou, Daher Mahmoud. "Réalisation et optimisation de transistors HEMT GaN forte puissance et haute fréquence par technologie de transfert de couches sur substrat hôte". Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30046.
Pełny tekst źródłaWireless telecommunication market largely benefits from new nitride technologies, which reach outstanding performance compared with traditional technologies. Current research is opening up many new strategies and alternative solutions to address simultaneously antagonist considerations such as cost, performances and/or reliability. Most AlGaN / GaN HEMTs are fabricated on a low cost, highly resistive silicon substrate or on a much more expensive and supply sensitive SiC substrate. However, the electrical performance constraints required when these technologies are integrating into radar systems, satellites and in telecommunications systems make them dependent to the operating temperature parameter, mainly linked to the high power dissipation during static/dynamic energy transfer. Indeed, these components are capable of generating high power densities in the microwave range. However, the operating frequency increase leads an increase of the power dissipation, generating the self-heating phenomenon which influences the devices performance (ID,max,ft,fmax...). In this context, several solutions were already proposed in the literature (use of composite substrates, passivation of devices, etc.). Furthermore, the layer transfer technology to report HEMTs from growth substrate onto a host substrate with a good thermal conductivity (such as diamond substrate) is a promising solution, still poorly detailed to date. The objective of this thesis work is to improve the heat dissipation and thus the performance and reliability of high-frequency HEMT transistors by using a layer transfer technology. AlGaN / GaN heterostructures are grown on a silicon substrate by MOCVD at CHREA. After the fabrication of HEMTs on a silicon substrate, AlGaN / GaN devices (for which the silicon substrate has been removed) are transferred onto a CVD diamond substrate. This transfer is obtained by thermocompression bonding of sputtered AlN layers on each surface to be assembled (backside of the transistors and diamond substrate). This transfer process has not damaged the functionality of the transistors with short gate length (Lg = 80 nm). The AlGaN/GaN HEMTs with a 2x35 µm development transferred onto diamond of feature a current ID,max = 710 mA.mm-1, a cutoff frequency ft of 85GHz and an oscillation frequency fmax of 144GHz. However, this transfer technique requires optimization phases (especially to reduce thickness and improve the crystalline quality and thermal conductivity of AlN layers) in order to reduce the thermal resistance of this adhesion layer and to limit the self-heating phenomenon noted at the end of this thesis work
Diette, Frédéric. "Etude des transistors à effet de champ de type HEMT sur substrat GaAs et InP pour l'amplification de puissance en gamme millimétrique". Lille 1, 1998. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1998/50376-1998-267.pdf.
Pełny tekst źródłaDuszynski, Isabelle. "Réalisation et caractérisation électrique de transistors HEMTs AlInAs/GaInAs de longueur de grille sub-50 nanomètres et de transistors sans couche tampon". Lille 1, 2005. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2005/50376-2005-346.pdf.
Pełny tekst źródłaAinsi, en augmentant ce rapport à 1,5 (cas des transistors sur barrière fine), on obtient une fréquence ft de 253GHz et une fréquence fmax de 380GHz. La dernière structure, à barrière fine et mixte, nous a permis d'obtenir des fréquences ft de l'ordre de 270GHz rien qu'en augmentant légèrement l'épaisseur de la barrière (puisque la grille a été déposée sur la Couche d'InP). Ces premiers résultats indiquent les potentialités offertes par l'utilisation d'une barrière Schottky mixte. Ces résultats pourraient être améliorés par l'utilisation d'un "double recess", ce qui permettrait de diminuer les zones trop importantes d'extensions de recess, à l'origine de la dégradation des performances fréquentielles de ces composants ultimes. L'amélioration de certains paramètres électriques liée à l'utilisation d'un recess mieux adapté permettrait d'aboutir à une fréquence ft de 520GHz, proche de l'état de l'art. Néanmoins, la réduction des dimensions atteint des limites, c'est pourquoi nous avons envisagé d'étudier des composants en rupture technologique avec les précédents transistors appelés "transistors sans couche tampon". L'idée est de venir supprimer la couche tampon qui est à l'origine d'une augmentation de la conductance de sortie par l'injection de porteurs dans cette couche. La réalisation technologique de ces composants est basée sur la technique de report de substrat, qui a été mise au point et adaptée à la réalisation d'un HEMT sans couche tampon. Les premiers résultats électriques indiquent que la technique de report de substrat affecte peu les caractéristiques de la couche active. Bien que nous ayons réalisé les premiers transistors sans couche tampon de longueur de grille 100nm, les caractéristiques électriques observées ne sont pas celles escomptées. Toutefois l'origine de ces faibles performances a été identifïée, et des solutions d'amélioration sont proposées
Elias, Caroline. "Étude d'héterostructures HEMT ScAlN/GaN élaborées par épitaxie sous jets moléculaires assistée ammoniac". Electronic Thesis or Diss., Université Côte d'Azur, 2023. http://www.theses.fr/2023COAZ4137.
Pełny tekst źródłaScAlN is a wide bandgap III-Nitride semiconductor well known for its piezoelectric properties. Its spontaneous and piezoelectric polarisation properties are also interesting for achieving heterojunctions with GaN in view of fabricating high electron mobility transistors (HEMTs). In these heterojunctions, the replacement of the AlGaN alloy by ScAlN presents several advantages, among them the possibility to generate two-dimensional electron gases (2DEGs) with much more carriers. It permits also to maintain a high carrier density in the channel of HEMTs with ScAlN barriers as thin as few nanometers, which allows to keep low access resistances and large saturation currents while limiting short channel effects in the submicron gate length transistors of millimeter-wave power amplifiers. Furthermore, the Sc0.18Al0.82N alloy is lattice matched with GaN, which means that noticeably reduced stress can be induced in the devices, an advantage for their reliability.However, to benefit all these advantages, the good control of the crystal growth of ScAlN alloy on GaN is necessary in order to obtain heterojunctions with the best crystal quality and the desired electrical behavior. Recent literature has reported encouraging results on ScAlN/GaN HEMTs grown by plasma- assisted molecular beam epitaxy and metalorganic vapor phase epitaxy. In this thesis, we studied the ammonia-source molecular beam epitaxy, a technique mastered in the laboratory since more than twenty years for GaN and AlGaN compounds. For the first time to our knowledge, ScAlN alloys have been grown on GaN with this technique. The effect of growth temperature has been studied first on relatively thick (25 nm) films in the 600°C to 800°C range. An optimal structural quality has been obtained for a growth temperature around 670°C, whereas the amount of scandium around 14% and the thickness vary very slightly in comparison to what was reported with plasma-assisted molecular beam epitaxy. Then, the effect of barrier thickness on 2DEG concentration has been studied. A maximum concentration around 4x1013/cm2 has been obtained for a thickness of 15 nm and it remained close to 2x1013/cm2 for a nominal thickness of 5 nm. XPS, SIMS and atom probe tomography confirmed the absence of heterogeneities in alloy composition. However, X-ray diffraction and transmission electron microscopy revealed the presence of a critical thickness beyond which crystal lattice parameter modulations appear. Furthermore, this critical thickness is reduced for films grown with scandium amounts around 22% and 30%.We succeeded in elaborating ScAlN/GaN HEMTs on buffer layers developed in one hand on silicon substrates, and in the other hand on GaN-on-sapphire templates. Our technological work consisted in the achievement of ohmic contacts with acceptable resistances (Rc~1 Ω.mm), the device isolation with mesa etching, the fabrication of diodes, van der Paw patterns and transistors able to deliver drain current density superior to 1 A/mm. Hall effect measurements performed on Van der Paw devices confirmed the high carrier concentration of 2 to 3 x1013/cm2 associated to a mobility of 500-600 cm2/V.s in the 2DEGs of HEMTs grown on silicon. HEMTs grown on GaN-on-sapphire exhibited similar carrier densities with slightly enhanced mobility (~740 cm2/V.s)
Teyssandier, Charles. "Contribution à la modélisation non-linéaire de transistors de puissance HEMT pseudomorphiques sur substrat AsGa : analyse des effets parasites". Limoges, 2008. http://aurore.unilim.fr/theses/nxfile/default/2b4e5b8a-1794-4270-b002-13d46f51d3c2/blobholder:0/2008LIMO4004.pdf.
Pełny tekst źródłaThe main objective of this work is the accurate modeling of UMS PHEMTs transistors process. Our model is based on extensive characterizations and can be easily integrated into nonlinear simulators that make it possible to use it in an industrial context. For telecommunication applications such as power amplifier, dissipated high power often leads to the increase of the internal of device temperature and hence to device performance degradation. The Design of MMICs based on GaAs PHEMTs process requires transistor models which take into account thermal effects. In this study, several methods are investigated to determinate thermal resistance and two thermal models are developed: the first consists of RC cells and the second is a distributed model extracted from 3D thermal simulations. As trap effects, breakdown phenomena are a part of dispersive effects in microwave transistors. Their behavior analysis gives limits of these components. We have specially studied impact ionization modeling. Measurements and simulations of load cycles and pulsed Y-parameters have been compared to determinate a cutoff frequency for impact ionization phenomenon
Meliani, Chafik. "Circuits intégrés amplificateurs à base de transistors HEMT pour les transmissions numériques à très haut débit (≥40 Gbit/s)". Paris 7, 2003. http://www.theses.fr/2003PA077172.
Pełny tekst źródłaArehart, Aaron R. "Investigation of electrically active defects in GaN, AlGaN, and AlGaN/GaN high electron mobility transistors". The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1253626881.
Pełny tekst źródłaKolanowski, Christophe. "Conception, réalisation et analyse de mélangeurs millimétriques en technologies hybride et intégrée utilisant des transistors à effet de champ Hemt de types monogrille et bigrille". Lille 1, 1996. http://www.theses.fr/1996LIL10048.
Pełny tekst źródłaRavindran, Vinod. "Design and fabrication of boron-containing III-nitrides based high electron mobility transistors". Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47606.
Pełny tekst źródłaElkhou, Majda. "Modélisation hydrodynamique bidimensionnelle de transistors à effet de champ : analyse physique des limitations et des performances hyperfréquences des filières pHEMT sur GaAs et HEMT sur GaN pour l'amplification de puissance". Lille 1, 2004. https://pepite-depot.univ-lille.fr/RESTREINT/Th_Num/2004/50376-2004-49.pdf.
Pełny tekst źródłaFatimy, Abdelouahad El. "Détection et Emission Terahertz par les ondes de plasma dans des transistors HEMT à base d'hétérostructures GAN/AlGaN et InGaAs/InAlAs". Montpellier 2, 2007. https://tel.archives-ouvertes.fr/tel-00182726.
Pełny tekst źródłaWe report on detection of terahertz radiation by high electron mobility nanometer InGaAs/InAlAs transistors. The photovoltaic type of response was observed at the 1. 8–3. 1 THz frequency range, which is far above the cut-off frequency of the transistors. The experiments were performed in the temperature range from 10 to 80 K. The resonant response was observed and was found to be tunable by the gate voltage. The resonances were interpreted as plasma wave excitations in the gated two-dimensional electron gas. The minimum noise equivalent power was estimated, showing possible application of these transistors in sensing of terahertz radiation. Also, we report on the demonstration of room temperature, tuneable terahertz detection obtained by 50 nm gate length InGaAs/InAlAs High Electron Mobility Transistors (HEMT). We show that the physical mechanism of the detection is related to the plasma waves excited in the transistor channel and that the increasing of the drain current leads to the transformation of the broadband detection to the resonant and tuneable one. We also show that the cap layer regions significantly affect the plasma oscillation spectrum in HEMT by decreasing the resonant plasma frequencies. In addition we report on terahertz emission by two-dimensional electron plasma oscillations in nanometric transistors at room temperature. Previously, the THz emission was reported only at 4,2 K in a 60 nm InGaAs high electron mobility transistor. We observe the room temperature emission for transistors based on two types of heterostructures- InGaAs/InAlAs and AlGaN/GaN. For both types we obtain a well defined source drain voltage threshold for the integrated emission, which depends on the gate bias. For InGaAs/InAlAs, we observe only emission signal integrated over the total frequency range (0. 1 – 10 THz). High intensity of the Thz emission from GaN/AlGaN structures allowed analysing its spectral content. The emission is interpreted as resulting from a current driven plasma instability leading to oscillations in the transistor channel (Dyakonov–Shur instability)
Astre, Guilhem. "Fiabilité des dispositifs HEMT en technologie GaN". Phd thesis, Toulouse 3, 2012. http://thesesups.ups-tlse.fr/1980/.
Pełny tekst źródłaReliability in GaN based devices still motivates numerous studies because the involved degradation mechanisms are different from that in III-V narrow bandgap devices. Direct investigations on high electron mobility transistors (HEMT) are performed with low frequency noise (LFN) measurements, pulsed electrical characterization and deep level transient spectroscopy. The first part of this thesis deals with generalities on AlGaN/GaN High electron mobility transistors and their technological particularities. The second part deals with the presentation of the diagnostic tools used in this study. A low frequency noise bench developed in LAAS-CNRS allowing measurements from few hertz up to 1 MHz is described, an original method of electrical pulsed characterization has and current deep level spectroscopy bench. In the third part of this study, low frequency noise is used to assess effects of deuterium (H+ ions) in diffusion condition on the robustness of 0. 25 *2*75 µm² gate area AlGaN/GaN high electron mobility transistors (HEMT) grown on Si substrate. H+ Ions are diffused from the above AlGaN/GaN layer through the AlGaN/GaN interface and GaN layer, notably under the gated channel where the defects are located. In the fourth part, undoped AlGaN/GaN devices grown on silicon substrate have been stressed at a junction temperature of 175°C. Gate-lag and drain-lag measurements method have been performed versus different quiescent bias points and under different pulse conditions. This method allows the discrimination of each lag phenomenon as well as the thermal contribution. Thus it is possible to track and model the trapping mechanisms versus bias conditions. This electrical modeling is completed with LFN measurements and deep level transient spectroscopy, which is largely used for reliability investigations
Malonis, Andrew C. "Quantitative defect spectroscopy on operating AlGaN/GaN high electron mobility transistors". The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1259597046.
Pełny tekst źródłaMELIANI, Chafik. "Circuits intégrés amplificateurs à base de transistors HEMT pour les transmissions numériques à très haut débit (>=40 Gbit/s)". Phd thesis, Université Paris-Diderot - Paris VII, 2003. http://tel.archives-ouvertes.fr/tel-00007587.
Pełny tekst źródła