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Étude et extraction des paramètres de bruit dans un transistor MesfetEddini, Abdel-ilah. January 2001 (has links)
Thèses (M.Sc.A.)--Université de Sherbrooke (Canada), 2001. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.
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Développement d'un procédé de fabrication de transistors en technologie MESFETLanglois, Pierre L. January 2004 (has links)
Thèses (M.Sc.A.)--Université de Sherbrooke (Canada), 2004. / Titre de l'écran-titre (visionné le 20 juin 2006). Publié aussi en version papier.
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GaAs MESFET modeling and its applicationsHo, Wai January 1993 (has links)
No description available.
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Developing low distortion linear and nonlinear circuits with GaAs FETs using the Parker Skellern modelWebster, Danny Richard January 1996 (has links)
No description available.
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ZnO-based metal-semiconductor field-effect transistors / ZnO-basierte Metall-Halbleiter FeldeffekttransistorenFrenzel, Heiko 03 November 2010 (has links) (PDF)
Die vorliegende Arbeit befasst sich mit der Entwicklung, Herstellung und Untersuchung von ZnO-basierten Feldeffekttransistoren (FET). Dabei werden im ersten Teil Eigenschaften von ein- und mehrschichtigen Isolatoren mit hohen Dielektrizitätskonstanten betrachtet, die mittels gepulster Laserabscheidung (PLD) dargestellt wurden. Die elektrischen und kapazitiven Eigenschaften dieser Isolatoren innerhalb von Metall-Isolator-Metall (MIM) bzw. Metall-Isolator-Halbleiter (MIS) Übergängen wurden untersucht. Letzterer wurde schließlich als Gate-Struktur in Metall-Isolator-Halbleiter-FET (MISFET) mit unten (backgate) bzw. oben liegendem Gate (topgate) genutzt. Der zweite Teil konzentriert sich auf Metal-Halbleiter-FET (MESFET), die einen Schottky-Kontakt alsGate nutzen. Dieser wurde mittels reaktiver Kathodenzerstäubung (Sputtern) von Ag, Pt, Pd oder
Au unter Einflußvon Sauerstoff hergestellt. ZnO-MESFET stellen eine vielversprechende Alternative zu den bisher in der Oxid-basierten Elektronik verwendeten MISFET dar. Durch die Variation des
verwendeten Gate-Metalls, Dotierung, Dicke und Struktur des Kanals und Kontakstruktur, wurde ein Herstellungsstandard gefunden, der zu weiteren Untersuchungen herangezogen wurde. So wurde die
Degradation der MESFET unter Belastung durch dauerhaft angelegte Spannung, Einfluss von Licht und erhöhten Temperaturen sowie lange Lagerung getestet. Weiterhin wurden ZnO-MESFET auf industriell
genutztem Glasssubstrat hergestellt und untersucht, um die Möglichkeit einer großflächigen Anwendung in Anzeigeelementen aufzuzeigen. Einfache integrierte Schaltungen, wie Inverter und
ein NOR-Gatter, wurden realisiert. Dazu wurden Inverter mit sogenannten Pegelschiebern verwendet, welche die Ausgangsspannung des Inverters so verschieben, dass eine logische Aneinanderreihungvon Invertern möglich wird. Schließlich wurden volltransparente MESFET und Inverter, basierend auf neuartigen transparenten gleichrichtenden Kontakten demonstriert.
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Concurrent mixed mode modelling of active strip antennasMcDowall, David Stewart January 1993 (has links)
No description available.
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Zinc Oxide MESFET TransistorsTurner, Gary Chandler January 2009 (has links)
Zinc oxide is a familiar ingredient in common household items including sunscreen and medicines. It
is, however, also a semiconductor material. As such, it is possible to use zinc oxide (ZnO) to make
semiconductor devices such as diodes and transistors. Being transparent to visible light in its
crystalline form means that it has the potential to be the starting material for so-called 'transparent
electronics', where the entire device is transparent. Transparent transistors have the potential to
improve the performance of the electronics currently used in LCD display screens.
Most common semiconductor devices require the material to be selectively doped with specific
impurities that can make the material into one of two electronically distinct types – p- or n-type.
Unfortunately, making reliable p-type ZnO has been elusive to date, despite considerable efforts
worldwide. This lack of p-type material has hindered development of transistors based on this
material.
One alternative is a Schottky junction, which can be used as the active element in a type of transistor
known as a metal-semiconductor field effect transistor, MESFET. Schottky junctions are traditionally
made from noble metal layers deposited onto semiconductors. Recent work at the Canterbury
University has shown that partially oxidised metals may in fact be a better choice, at least to zinc
oxide.
This thesis describes the development of a fabrication process for metal-semiconductor field effect
transistors using a silver oxide gate on epitaxially grown zinc oxide single crystals. Devices were
successfully produced and electrically characterised. The measurements show that the technology has
significant potential.
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Magneto-transport properties of GaAs microstructures near the metal-insular transitionGriffiths, Timothy Giles d'Arcy January 1997 (has links)
No description available.
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The Use of Voltage Compliant Silicon on Insulator MESFETs for High Power and High Temperature Pulse Width Modulated Drive CircuitsJanuary 2010 (has links)
abstract: Silicon Carbide (SiC) junction field effect transistors (JFETs) are ideal for switching high current, high voltage loads in high temperature environments. These devices require external drive circuits to generate pulse width modulated (PWM) signals switching from 0V to approximately 10V. Advanced CMOS microcontrollers are ideal for generating the PWM signals but are limited in output voltage due to their low breakdown voltage within the CMOS drive circuits. As a result, an intermediate buffer stage is required between the CMOS circuitry and the JFET. In this thesis, a discrete silicon-on-insulator (SOI) metal semiconductor field effect transistor (MESFET) was used to drive the gate of a SiC power JFET switching a 120V RMS AC supply into a 30Ω load. The wide operating temperature range and high breakdown voltage of up to 50V make the SOI MESFET ideal for power electronics in extreme environments. Characteristic curves for the MESFET were measured up to 250°C.; To drive the JFET, the MESFET was DC biased and then driven by a 1.2V square wave PWM signal to switch the JFET gate from 0 to 10V at frequencies up to 20kHz. For simplicity, the 1.2V PWM square wave signal was provided by a 555 timer. The JFET gate drive circuit was measured at high temperatures up to 235°C.; The circuit operated well at the high temperatures without any damage to the SOI MESFET or SiC JFET. The drive current of the JFET was limited by the duty cycle range of the 555 timer used. The SiC JFET drain current decreased with increased temperature. Due to the easy integration of MESFETs into SOI CMOS processes, MESFETs can be fabricated alongside MOSFETs without any changes in the process flow. This thesis demonstrates the feasibility of integrating a MESFET with CMOS PWM circuitry for a completely integrated SiC driver thus eliminating the need for the intermediate buffer stage. / Dissertation/Thesis / M.S. Electrical Engineering 2010
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Optimizing the Design of Partially and Fully Depleted MESFETs for Low Dropout RegulatorsJanuary 2010 (has links)
abstract: The constant scaling of supply voltages in state-of-the-art CMOS processes has led to severe limitations for many analog circuit applications. Some CMOS processes have addressed this issue by adding high voltage MOSFETs to their process. Although it can be a completely viable solution, it usually requires a changing of the process flow or adding additional steps, which in turn, leads to an increase in fabrication costs. Si-MESFETs (silicon-metal-semiconductor-field-effect-transistors) from Arizona State University (ASU) on the other hand, have an inherent high voltage capability and can be added to any silicon-on-insulator (SOI) or silicon-on-sapphire (SOS) CMOS process free of cost. This has been proved at five different commercial foundries on technologies ranging from 0.5 to 0.15 μm. Another critical issue facing CMOS processes on insulated substrates is the scaling of the thin silicon channel. Consequently, the future direction of SOI/SOS CMOS transistors may trend away from partially depleted (PD) transistors and towards fully depleted (FD) devices. FD-CMOS are already being implemented in multiple applications due to their very low power capability. Since the FD-CMOS market only figures to grow, it is appropriate that MESFETs also be developed for these processes. The beginning of this thesis will focus on the device aspects of both PD and FD-MESFETs including their layout structure, DC and RF characteristics, and breakdown voltage. The second half will then shift the focus towards implementing both types of MESFETs in an analog circuit application. Aside from their high breakdown ability, MESFETs also feature depletion mode operation, easy to adjust but well controlled threshold voltages, and fT's up to 45 GHz. Those unique characteristics can allow certain designs that were previously difficult to implement or prohibitively expensive using conventional technologies to now be achieved. One such application which benefits is low dropout regulators (LDO). By utilizing an n-channel MESFET as the pass transistor, a LDO featuring very low dropout voltage, fast transient response, and stable operation can be achieved without an external capacitance. With the focus of this thesis being MESFET based LDOs, the device discussion will be mostly tailored towards optimally designing MESFETs for this particular application. / Dissertation/Thesis / Ph.D. Electrical Engineering 2010
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