Дисертації з теми "GaN Power and THz Devices"
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Zhang, Yuhao Ph D. Massachusetts Institute of Technology. "GaN-based vertical power devices." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/112002.
Повний текст джерелаThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 163-170).
Power electronics based on Gallium Nitride (GaN) is expected to significantly reduce the losses in power conversion circuits and increase the power density. This makes GaN devices very exciting candidates for next-generation power electronics, for the applications in electric vehicles, data centers, high-power and high-frequency communications. Currently, both lateral and vertical structures are considered for GaN power devices. In particular, vertical GaN power devices have attracted significant attention recently, due to the potential for achieving high breakdown voltage and current levels without enlarging the chip size. In addition, these vertical devices show superior thermal performance than their lateral counterparts. This PhD thesis addresses several key obstacles in developing vertical GaN power devices. The commercialization of vertical GaN power devices has been hindered by the high cost of bulk GaN. The first project in this PhD thesis demonstrated the feasibility of making vertical devices on a low-cost silicon (Si) substrate for the first time. The demonstrated high performance shows the great potential of low-cost vertical GaN-on-Si devices for 600-V level high-current and high-power applications. This thesis has also studied the origin of the off-state leakage current in vertical GaN pn diodes on Si, sapphire and GaN substrates, by experiments, analytical calculations and TCAD simulations. Variable-range-hopping through threading dislocations was identified as the main off-state leakage mechanism in these devices. The design space of leakage current of vertical GaN devices has been subsequently derived. Thirdly, a novel GaN vertical Schottky rectifier with trench MIS structures and trench field rings was demonstrated. The new structure greatly enhanced the reverse blocking characteristics while maintaining a Schottky-like good forward conduction. This new device shows great potential for using advanced vertical Schottky rectifiers for high-power and high-frequency applications. Finally, we investigated a fundamental and significant challenge for GaN power devices: the lack of reliable and generally useable patterned pn junctions. Two approaches have been proposed to make lateral patterned pn junctions. Two devices, junction barrier Schottky devices and super-junction devices, have been designed and optimized. Preliminary experimental results were also demonstrated for the feasibility of making patterned pn junctions and fabricating novel power devices.
by Yuhao Zhang.
Ph. D.
Unni, Vineet. "Next-generation GaN power semiconductor devices." Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/11984/.
Повний текст джерелаNakazawa, Satoshi. "Interface Charge Engineering in AlGaN/GaN Heterostructures for GaN Power Devices." Kyoto University, 2019. http://hdl.handle.net/2433/244553.
Повний текст джерелаLui, Dawei. "Active gate driver design for GaN FET power devices." Thesis, University of Bristol, 2017. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.730883.
Повний текст джерелаKumar, Ashwani. "Novel approaches to power efficient GaN and negative capacitance devices." Thesis, University of Sheffield, 2018. http://etheses.whiterose.ac.uk/22492/.
Повний текст джерелаLi, Ke. "Wide bandgap (SiC/GaN) power devices characterization and modeling : application to HF power converters." Thesis, Lille 1, 2014. http://www.theses.fr/2014LIL10080/document.
Повний текст джерелаCompared to traditional silicon (Si) semiconductor material, wide bandgap (WBG) materials like silicon carbide (SiC) and gallium nitride are gradually applied to fabricate power semiconductor devices, which are used in power converters to achieve high power efficiency, high operation temperature and high switching frequency. As those power devices are relatively new, their characterization and modeling are important to better understand their characteristics for better use. This dissertation is mainly focused on those WBG power semiconductor devices characterization, modeling and fast switching currents measurement. In order to measure their static characteristics, a single-pulse method is presented. A SiC diode and a "normally-off" SiC JFET is characterized by this method from ambient temperature to their maximal junction temperature with the maximal power dissipation around kilowatt. Afterwards, in order to determine power device inter-electrode capacitances, a measurement method based on the use of multiple current probes is proposed and validated by measuring inter-electrode capacitances of power devices of different technologies. Behavioral models of a Si diode and the SiC JFET are built by using the results of the above characterization methods, by which the evolution of the inter-electrode capacitances for different operating conditions are included in the models. Power diode models are validated with the measurements, in which the current is measured by a proposed current surface probe
Brooks, Clive Raymond. "GaN microwave power FET nonlinear modelling techniques." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4306.
Повний текст джерелаENGLISH ABSTRACT: The main focus of this thesis is to document the formulation, extraction and validation of nonlinear models for the on-wafer gallium nitride (GaN) high-electron mobility (HEMT) devices manufactured at the Interuniversity Microelectronics Centre (IMEC) in Leuven, Belgium. GaN semiconductor technology is fast emerging and it is expected that these devices will play an important role in RF and microwave power amplifier applications. One of the main advantages of the new GaN semiconductor technology is that it combines a very wide band-gap with high electron mobility, which amounts to higher levels of gain at very high frequencies. HEMT devices based on GaN, is a fairly new technology and not many nonlinear models have been proposed in literature. This thesis details the design of hardware and software used in the development of the nonlinear models. An intermodulation distortion (IMD) measurement setup was developed to measure the second and higher-order derivative of the nonlinear drain current. The derivatives are extracted directly from measurements and are required to improve the nonlinear model IMD predictions. Nonlinear model extraction software was developed to automate the modelling process, which was fundamental in the nonlinear model investigation. The models are implemented in Agilent’s Advanced Design System (ADS) and it is shown that the models are capable of accurately predicting the measured S-parameters, large-signal singletone and two-tone behaviour of the GaN devices.
AFRIKAANSE OPSOMMING: Die hoofdoel van hierdie tesis is om die formulering, ontrekking en validasie van nie-lineêre modelle vir onverpakte gallium nitraat (GaN) hoë-elektronmobilisering transistors (HEMTs) te dokumenteer. Die transistors is vervaaardig by die Interuniversity Microelectronics Centre (IMEC) in Leuven, België. GaN-halfgeleier tegnologie is besig om vinnig veld te wen en daar word voorspel dat hierdie transistors ʼn belangrike rol gaan speel in RF en mikrogolf kragversterker toepassings. Een van die hoof voordele van die nuwe GaN-halfgeleier tegnologie is dat dit 'n baie wyd band-gaping het met hoë-elektronmobilisering, wat lei tot hoë aanwins by mikrogolf frekwensies. GaN HEMTs is 'n redelik nuwe tegnologie en nie baie nie-lineêre modelle is al voorgestel in literatuur nie. Hierdie tesis ondersoek die ontwerp van die hardeware en sagteware soos gebruik in die ontwikkeling van nie-lineêre modelle. 'n Intermodulasie distorsie-opstelling (IMD-opstelling) is ontwikkel vir die meting van die tweede en hoër orde afgeleides van die nie-lineêre stroom. Die afgeleides is direk uit die metings onttrek en moet die nie-lineêre IMD-voorspellings te verbeter. Nie-lineêre onttrekking sagteware is ontwikkel om die modellerings proses te outomatiseer. Die modelle word geïmplementeer in Agilent se Advanced Design System (ADS) en bewys dat die modelle in staat is om akkurate afgemete S-parameters, grootsein enkeltoon en tweetoon gedrag van die GaN-transistors te kan voorspel.
Borga, Matteo. "Characterization and modeling of GaN-based transistors for power applications." Doctoral thesis, Università degli studi di Padova, 2019. http://hdl.handle.net/11577/3422355.
Повний текст джерелаWaller, William Michael. "Optimisation of AlGaN/GaN power devices : interface analysis, fieldplate control and current collapse." Thesis, University of Bristol, 2018. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.743050.
Повний текст джерелаMurillo, Carrasco Luis. "Modelling, characterisation and application of GaN switching devices." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/modelling-characterisation-and-application-of-gan-switching-devices(a227368d-1029-4005-950c-2a098a5c5633).html.
Повний текст джерелаBaker, Bryant. "A 3.6 GHz Doherty Power Amplifier with a 40 dBm Saturated Output Power using GaN on SiC HEMT Devices." PDXScholar, 2014. https://pdxscholar.library.pdx.edu/open_access_etds/1781.
Повний текст джерелаPower, Máire. "Characterisation of temperature and mechanical stress in AlGaN/GaN devices designed for power electronic applications." Thesis, University of Bristol, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.715812.
Повний текст джерелаBajwa, Adeel Ahmad [Verfasser], and Jürgen [Akademischer Betreuer] Wilde. "New assembly and packaging technologies for high-power and high-temperature GaN and SiC devices." Freiburg : Universität, 2015. http://d-nb.info/1119327814/34.
Повний текст джерелаTsai, Kaichien. "EMI Modeling and Characterization for Ultra-Fast Switching Power Circuit Based on SiC and GaN Devices." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1385983252.
Повний текст джерелаStocco, Antonio. "Reliability and failure mechanisms of GaN HEMT devices suitable for high-frequency and high-power applications." Doctoral thesis, Università degli studi di Padova, 2012. http://hdl.handle.net/11577/3422493.
Повний текст джерелаQuesta tesi riassume i principali risultati ottenuti nello studio dell'affidabilità e dei principali meccanismi di guasto nei transistor ad alta mobilità basati su Nitruro di Gallio (GaN-HEMT). L'attività di ricerca dei tre anni di dottorato è stata incentrata (i) sulle principali problematiche affidabilistiche degli HEMT su GaN adatti sia alle applicazioni ad alta frequenza, come il campo delle telecomunicazioni o satellitare, sia alle applicazioni ad alta potenza, come il campo degli switch per alta potenza, (ii) sull'analisi fisica del degrado causato dall'applicazione di alti campi elettrici, (iii) e sull'analisi approfondita di alcuni effetti parassiti che influenzano le caratteristiche statiche e dinamiche di tale tecnologia. Il lavoro ha seguito le ultime fasi del progetto europeo KorriGaN e alcune collaborazioni con centri di ricerca europei e aziende private, integrando la possibilità di capire quali possano essere le problematiche attualmente considerate più critiche in ogni specifica applicazione degli HEMT su GaN, con l'opportunità di trasferire le conoscenze acquisite anche all'interno degli altri campi operativi. La prima parte della tesi riassume tutta l'attività svolta all'interno del progetto Task-Force, attività conclusiva del settore affidabilità del progetto europeo KorriGaN (Key ORganisation for Research on Integrated circuit in GaN technology). Scopo del progetto era individuare le condizioni di funzionamento più critiche nell'ultimo set di dispositivi sviluppati a partire dai risultati ottenuti durante i precedenti anni di progetto, dando particolare importanza ai meccanismi di guasto responsabili della riduzione delle principali prestazioni nel breve e nel medio periodo, e ai diversi comportamenti indotti dalle diverse qualità dei substrati utilizzati nella crescita di tali dispositivi. I test di affidabilità a canale chiuso hanno dimostrato un significativo miglioramento della robustezza rispetto ai dispositivi sviluppati nei precedenti anni di progetto, con tensioni critiche di rottura oltre i 100V. Tali risultati sono stati confermati in tutti i wafer, indipendentemente dalla qualità del substrato, sottolineando come un buon processing dei dispositivi possa completamente mascherare la scarsa qualità dell'epitassia o dei substrati utilizzati. A canale aperto invece, l'analisi dei principali meccanismi di guasto e dei fattori di accelerazione del degrado ha mostrato un particolare meccanismo di degradazione accelerato dagli elettroni caldi (hot electrons) presenti all'interno del canale, con una trascurabile influenza della temperatura di test. Questo risultato è uno dei primi che mostra chiaramente l'influenza degli elettroni caldi nei meccanismi di degrado degli HEMT basati su Nitruro di Gallio. Analoghi studi su affidabilità e meccanismi di guasto sono stati eseguiti all'interno dell'attività di collaborazione con l'Agenzia Spaziale Europea. In particolare, l'attività è stata sviluppata sia all'interno dei laboratori di microelettronica di Padova, sia presso il centro di ricerca dell'Agenzia Spaziale ESA-ESTEC in Olanda, per un periodo complessivo di mobilità di 5 mesi. Gli studi sono stati eseguiti su una tecnologia di dispositivi ormai abbastanza consolidata, adattata alle esigenze specifiche delle applicazioni satellitari. I risultati hanno mostrato una buona stabilità delle principali perfomance DC e RF dei dispositivi al variare delle temperatura, e una buona stabilità nei test di storage fino ai 350°C, temperatura critica alla quale i diodi di gate cominciano rapidamente a degradare. Una significativa affidabilità è stata inoltre rilevata sia nei test a breve termine, con ottima stabilità oltre i 100V di tensione di drain a temperatura ambiente e ad alte temperature, sia nei test a lungo termine, eseguiti sui dispositivi designati per l'applicazione spaziale con test ad elevate temperature di giunzione. La successiva parte della tesi tratta un'analisi approfondita dell'affidabilità a canale chiuso dei transistor su GaN, seguendo precedenti lavori volti allo stesso scopo. Molti studi sono stati eseguiti per comprendere meglio quali siano i meccanismi di guasto coinvolti nella degradazione del gate delle precedenti tecnologie di GaN-HEMT, a causa di alcune questioni ancora irrisolte sulle quali la letteratura non ha ancora dato una completa chiarificazione. Nonostante la definizione di "critical voltage" (tensione critica) ormai comunemente accettata, alcuni test sul comportamento del gate in polarizzazione inversa hanno evidenziato risultanti contrastanti, suggerendo un diverso meccanismo di guasto correlato alla difettosità iniziale del campione. Altre analisi in polarizzazione costante hanno mostrato lo stesso meccanismo di guasto a tensioni di gate ben al di sotto della tensione critica. In seguito, su alcuni campioni sono state eseguite approfondite indagini di guasto per meglio comprendere l'evoluzione fisica del meccanismo di rottura, seguendo alcuni studi recentemente riportati in letteratura. Guidati dalle misure di elettroluminescenza (EL) precedentemente ottenute, tali analisi hanno permesso di verificare la presenza di difetti pre-esistenti e solo in certi casi di identificare la comparsa di alcuni difetti indotti dallo stress, evidenziando l'enorme difficoltà e talvolta l'impossibilità di localizzare dei difetti con dimensioni di scala nanometrica nei diversi strati di semiconduttore (cracks), almeno durante le prime fasi di degrado del campione. L'ultima parte della tesi riporta alcune indagini approfondite su specifici effetti parassiti presenti negli HEMT su GaN, in particolar modo analizzando l'effetto kink e il collasso di corrente (current collapse). Questi studi sono stati svolti all'interno del progetto europeo MANGA (Manufacturable GaN), nel settore dedicato all'indagine dei livelli energetici responsabili degli effetti parassiti. Studiando alcuni dispositivi appartenenti a tecnologie meno recenti, è stato possibile correlare la presenza dell'effetto kink con un aumento inusuale dello spettro di elettro-luminescenza nel range della banda rosso-gialla, a sua volta correlato con un largo picco di emissione nel giallo rilevato durante misure di catodo-luminescenza negli stessi dispositivi. Tali studi confermano un precedente lavoro in cui si assume che l'effeto kink sia originato dall'interazione degli elettroni nel canale con due livelli energetici parassiti presenti all'interno dell'energy gap del GaN. Studiando invece alcuni dispositivi HEMT basati sull'eterostruttura AlGaN/GaN, ma con differenti composizioni dello strato barriera e drogaggio dello strato buffer, è stato possibile correlare la concentrazione del ferro, usato come drogante all'interno del buffer, con un incremento del current collapse nei punti di polarizzazione a maggior campo elettrico, identificando poi l'energia di attivazione della trappola responsabile di tale degrado delle caratteristiche dinamiche. L'uso combinato di misure SIMS (Secondary Ion Mass Spectroscopy) e simulazioni numeriche hanno permesso di dare una dimostrazione fisica dell'effetto osservato nelle misure di laboratorio, confermando sia i risultati ottenuti in termini di collasso di corrente, sia la valutazione sperimentale dell'energia di attivazione della trappola.
Perrin, Rémi. "Characterization and design of high-switching speed capability of GaN power devices in a 3-phase inverter." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI001/document.
Повний текст джерелаThe french industrial project MEGaN targets the development of power module based on GaN HEMT transistors. One of the industrial applications is the aeronautics field with a high-constraint on the galvanic isolation (>100 kV/s) and ambient temperature (200°C). The intent of this work is the power module block (3 phases inverter 650 V 30 A). The goal is to obtain a small footprint module, 30 cm2, with necessary functions such as gate driver, gate driver power supply, bulk capacitor and current phase sensor. This goal implies high efficiency as well as respect of the constraint of galvanic isolation with an optimized volume. This dissertation, besides the state of the art of power modules and especially the GaN HEMT ones, addressed a control signal isolation solution based on coreless transformers. Different prototypes based on coreless transformers were characterized and verified over 3000 hours in order to evaluate their robustness. The different studies realized the characterization of the different market available GaN HEMTs in order to mature a circuit simulation model for various converter topologies. In the collaborative work of the project, our contribution did not focus on the gate driver chip design even if experimental evaluation work was made, but a gate driver power supply strategy. The first gate driver isolated power supply design proposition focused on the low-voltage GaN HEMT conversion. The active-clamp Flyback topology allows to have the best trade-off between the GaN transistors and the isolation constraint of the transformer. Different transformer topolgies were experimentally performed and a novel PCB embedded transformer process was proposed with high-temperature capability. A lamination process was proposed for its cost-efficiency and for the reliability of the prototype (1000 H cycling test between - 55; + 200°C), with 88 % intrinsic efficiency. However, the transformer isolation capacitance was drastically reduced compared to the previous prototypes. 2 high-integrated gate driver power supply prototypes were designed with: GaN transistors (2.4 MHz, 2 W, 74 %, 6 cm2), and with a CMOS SOI dedicated chip (1.2 MHz, 2 W, 77 %, 8.5 cm2). In the last chapter, this dissertation presents an easily integrated solution for a phase current sensor based on the magnetoresistance component. The comparison between shunt resistor and magnetoresistance is experimentally performed. Finally, two inverter prototypes are presented, with one multi-level gate driver dedicated for GaN HEMT showing small switching loss performance
Ciarkowski, Timothy A. "Low Impurity Content GaN Prepared via OMVPE for Use in Power Electronic Devices: Connection Between Growth Rate, Ammonia Flow, and Impurity Incorporation." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/94551.
Повний текст джерелаDoctor of Philosophy
GaN is a compound semiconductor which has the potential to revolutionize the high power electronics industry, enabling new applications and energy savings due to its inherent material properties. However, material quality and purity requires improvement. This improvement can be accomplished by reducing contamination and growing under extreme conditions. Newly available bulk substrates with low defects allow for better study of material properties. In addition, very thick films can be grown without cracking on these substrates due to exact lattice and thermal expansion coefficient match. Through chemical and electrical measurements, this work aims to find optimal growth conditions for high purity GaN without a severe impact on growth rate, which is an important factor from an industry standpoint. The proposed thicknesses of these devices are on the order of one hundred microns and requires tight control of impurities.
Badawi, Nasser [Verfasser], Sibylle [Akademischer Betreuer] Dieckerhoff, Sibylle [Gutachter] Dieckerhoff, Andreas [Gutachter] Lindemann, and Nando [Gutachter] Kaminski. "Experimental investigation of GaN power devices : dynamic performance, robustness and degradation / Nasser Badawi ; Gutachter: Sibylle Dieckerhoff, Andreas Lindemann, Nando Kaminski ; Betreuer: Sibylle Dieckerhoff." Berlin : Technische Universität Berlin, 2019. http://d-nb.info/1174990295/34.
Повний текст джерелаYan, Ning. "High-frequency Current-transformer Based Auxiliary Power Supply for SiC-based Medium Voltage Converter Systems." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/101507.
Повний текст джерелаM.S.
Recently, 10 kV silicon carbide (SiC) MOSFET receives strong attention for medium voltage applications. Asit can switch at very high speed, e.g. > 50 V/ns, the converter system can operate at higher switching frequency condition with very small switching losses compared to silicon (Si) IGBT [8]. However, the fast dv/dt noise also creates the common mode current via coupling capacitors distributed inside the converter system, thereby introducing lots of electromagnetic interference (EMI) issues. Such issues typically occur within the gate driver power supplies due to the high dv/dt noises across the input and output of the supply. Therefore, the ultra-small coupling capacitor (<5 pF) of a gate driver power supply is strongly desired.[37] To satisfy the APS demands for high power modular converter system, a solution is proposed in this thesis. This work investigates the design of 1 MHz isolated APS using gallium nitride (GaN) devices with medium voltage insulation reinforcement. By increasing switching frequency, the overall converter size could be reduced dramatically. To achieve a low Ccm value and medium voltage insulation of the system, a current-based transformer with a single turn on the sending side is designed. By adopting LCCL-LC resonant topology, a current source is formed as the output of sending side circuity, so it can drive multiple loads importantly with a maximum of 120 W. At the same time, ZVS can use realized with different load conditions. The receiving side is a regulated stage, so the output voltage can be easily adjusted and it can operate in a load fault condition. Different insulation solutions will be introduced and their effect on Ccm will be discussed. To further reduce Ccm, shielding will be introduced. Overall, this proposed APS can achieve a breakdown voltage of over 20 kV and PDIV up to 16.6 kV with Ccm<5 pF. Besides, multi-load driving ability is able to achieve with a maximum of 120 W. ZVS can be realized. In the end, the experiment results will be provided.
Souguir-Aouani, Amira. "Conception d’une nouvelle génération de redresseur Schottky de puissance en Nitrure de Gallium (GaN), étude, simulation et réalisation d’un démonstrateur." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSEI093/document.
Повний текст джерелаThere is increasing interest in the fabrication of power semiconductor devices in home automation applications. Power semiconductor technology has been essentially confined to Si. Recently, new materials with superior properties are being investigated as potential replacements, in particular silicon carbide (SiC) and gallium nitride (GaN). The current state of development of SiC technology is much more mature than for GaN. However, the use of 4H-SiC is not a cost effective solution for realizing a medium and high voltage Schottky diode. Recent advances on the development of thick n-type GaN epilayers on Si substrate offer new prospects for the development of a low-cost Schottky rectifiers for at least medium voltage range 600 V. In the context of our thesis, two types of GaN based rectifier architectures have been studied. The first one is a pseudo-vertical architecture proposed during previous G2ReC project. The second one has a lateral structure with AlGaN/GaN heterojunction, derived from a HEMT structure. The optimization of the Schottky rectifiers has been achieved by finite element simulations. As a first step, the models are implemented in the software and adjusted with the parameters described in the literature. The influence of the geometrical and physical parameters on the specific on-resistance and on the breakdown voltage has been analysed. Finally, the test devices have been realized and characterized to optimize and to validate the parameters of these models. These studies lead to identify the limits of the structures and create a new generation of powerful structures
Wijewardane, M. Anusha. "Exhaust system energy management of internal combustion engines." Thesis, Loughborough University, 2012. https://dspace.lboro.ac.uk/2134/9829.
Повний текст джерелаNickerl, Georg, Irena Senkoska, and Stefan Kaskel. "Tetrazine functionalized zirconium MOF as an optical sensor for oxidizing gases." Royal Society of Chemistry, 2015. https://tud.qucosa.de/id/qucosa%3A36053.
Повний текст джерелаSoni, Ankit. "Physics Based Design & Development of Gallium Nitride High Electron Mobility Transistors (HEMTs) & Schottky Barrier Diodes for Power and RF Applications." Thesis, 2021. https://etd.iisc.ac.in/handle/2005/5177.
Повний текст джерелаTzou, An-Jye, and 鄒安傑. "The Study of Device Performance and Dynamic Characteristic Improvement for GaN-on-Si High Power Devices." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/p3z3u3.
Повний текст джерелаChen, Shang Cyun, and 陳尚群. "The Investigation of Various Fe Concentration in Buffer Layer of GaN Power Devices." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/3va7fg.
Повний текст джерелаLien, Yi-Wei, and 連羿韋. "Design, Fabrication, and Analysis of High Power and High Speed GaN-based Devices on The Si Substrate." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/62082565100219440059.
Повний текст джерела國立清華大學
電子工程研究所
102
This thesis focuses on high performance AlGaN/GaN heterojunction devices on Si substrate for high power and high frequency applications. For high voltage applications, the contact engineering was investigated to improve device off-state characteristics in GaN on Si devices by using two different approaches, including a selective Si diffusion structure for AlGaN/GaN SBDs and a hybrid Schottky-Ohmic drain electrode structure for AlGaN/GaN HEMTs. Both two approaches are proposed to alleviate the E-field peaks at the alloy spikes and further enhance the breakdown voltage by manipulating the E-field around Ohmic contact. First, a selective Si diffusion approach is proposed to reduce Schottky onset voltage from 1.3 V to 1.0 V and enhance the reverse blocking capability up to 20%simultaneously. With Si diffused layer underneath cathode, a low and stable contact resistance and relatively smooth ohmic metal morphology can be obtained. Second, a hybrid drain device shows nearly zero drain onset voltage and reduces drain leakage current by one order of magnitude, comparing with that of traditional ohmic drain devices. Both the gate-drain and buffer breakdown can be improved. We also investigated the impact of Schottky extension length Lext on device characteristics. After optimizing Lext, the breakdown voltage can be enhanced up to 60% without clear on-resistance RON degradation. For high frequency applications, we proposed a method to directly extract the more convergent results for parasitic substrate resistance and capacitance in small signal model of GaN-on-Si HEMTs by using derivative method. The model is verified by in-house 200-nm T-gate AlGaN/GaN HEMTs. Also, the simulation is performed to analyze the impact of substrate effect on device high frequency characteristics.
Liu, Shih-Chien, and 劉世謙. "Performance Enhancement Technologies for GaN Power Devices." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/86079432075505825410.
Повний текст джерелаLiu, Chung-Hsing, and 劉宗興. "Parameter Verification of High Speed Depletion-Mode GaN Power Devices." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/23960232368822795484.
Повний текст джерела國立中央大學
電機工程學系
105
Gallium Nitride (GaN) power transistors exist better material properties than Si-based transistors such as higher electron mobility, higher breakdown voltage, higher current density, lower on-state resistance, lower gate charge and smaller output capacitance. It is particularly suitable to function as high speed switches for power electronic circuit applications. The thesis aims to design a circuit module to measure three electrical parameters of depletion-mode GaN power transistors in order to provide information for power electronic circuit design. Three major parameters include switching time, gate charge, and DC-IV curve. A detailed description of the designed circuits is given and measurement results are compared to the estimation model. The measurement error is about 32% because of design issues of the circuit module.
Chou, Hsin-Ping, and 周歆苹. "Study on Thermal Performance of Packaged High Power GaN Devices." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/u6w998.
Повний текст джерела國立交通大學
機械工程系所
106
Work on wide band gap materials and devices has been going on for many years. One of the important wide band gap materials showing great promise for the future for both switching and power applications is Gallium Nitride (GaN). Heteroepitaxial GaN devices on Si is restricted to lateral device structures. The most common lateral device structure is the HEMT (High Electron Mobility Transistor). Wide band gap and high critical field give GaN an advantage when high power is a key desirable device feature. However, the relatively poor thermal conductivity of GaN makes heat management for GaN devices a challenge for system designers to contend with. This study presents the packaging development of high power AlGaN/GaN HEMTs on Si substrate. By foremost carrying out electro-thermal simulation with Silvaco TCAD and related thermal measurements with infrared thermography and Raman spectroscopy for basic 5 mm GaN HEMTs, the location of hot spot in operating device can be obtained. Based on the outcome, further packaged GaN HEMT is analyzed. The packaging structure is designed on the device periphery surface for enhancing Si substrate thermal dissipation. The effects of structure design and fabrication processes on the device performance were studied. In addition, this study investigates the thermal performance of packaged normally-on multi-finger AlGaN/GaN HEMTs that are cascaded with a low-voltage MOSFET and a SiC Schottky barrier diode (SBD). The analytical results are confirmed by comparing them with the infrared thermographic measurements and numerical results obtained from simulation using Ansys Icepak. To increase the output power, the GaN HEMTs are connected in parallel and the related researches are also displayed. Finally, the packaged GaN devices are applied in power conversion systems.
Acurio, Méndez Eliana Maribel, Felice Crupi, and Lionel Trojman. "Reliability of GaN-based devices for Energy Efficient Power Applications." Thesis, 2019. http://hdl.handle.net/10955/1717.
Повний текст джерелаThe wide spectrum of power electronics applications, including their role in renewable energy conversion and energy saving, require the innovation from conventional Silicon (Si) technology into new materials and architectures that allow the fabrication of increasingly lightweight, compact, efficient and reliable devices. However, the trade-off between long lifetime, high performance and low cost in the emerging technologies represents a huge limitation that has gained the attention of different research groups in the last years. Gallium Nitride (GaN) is a wide-bandgap semiconductor (WBGS) that constitutes an excellent candidate for high-power and high-frequency applications due to its remarkable features such as high operating temperature, high dielectric strength, high current density, high switching speed, and low on-resistance. Compared with its Silicon counterpart, GaN is superior in terms of high breakdown field ( 3 MV/cm), exceptional carrier mobility, and power dissipation. By taking into account other WBG materials such as SiC, GaN grown on Si substrates promises similar performance but at a much lower cost in the low to mid power and high-frequency range. Since GaN allows size and weight device reduction due to a better relationship between on-resistance and breakdown voltage, it is suitable for a variety of applications such as RF power amplifiers, power switching systems, sensors, detectors, etc. Especially, in the field of energy efficiency, GaN technology appears as a future successor of Si in power conversion circuits. However, some drawbacks related to technology cost, integration, and long-term reliability have to be overcome for its wide adoption in the power applications market. One of the worst inconveniences of AlGaN/GaN High Electron Mobility Transistors (HEMTs) is the normally-ON operation. Since a two-dimensional electron gas (2DEG) channel is formed at the AlGaN/GaN interface due to inherent material properties, a negative bias has to be applied at the gate to switch the device off. Among the proposed solutions to fabricate normally-OFF devices, the metaloxide/ insulator-semiconductor (MOS/MIS) structure with different insulators has shown remarkable improvements in gate leakage reduction and drain current increase. Also in AlGaN/GaN Schottky Barrier Diodes (SBDs), the introduction of a MOS structure to create a gated edge termination (GET) at the anode area has resulted in significant improvements in reverse diode leakage and forward diode voltage. Nevertheless, the improvement in the device performance by the introduction of a dielectric could seriously affect the device long-term reliability since additional degradation in this layer and at its interfaces with AlGaN or GaN occurs. In the case of conversion systems, power devices are continuously switched from an OFF-state condition at high drain bias to an ON-state condition at large drain current. Therefore, the reliability of GaN-based devices has to be proven for the complete ON/OFF operation. This dissertation focuses on providing a more comprehensive analysis of two main reliability issues related to the dielectric insertion under the gate/anode stacks by analyzing the use of different dielectric materials and device architectures. The first issue is the positive bias temperature instability (PBTI), which is related to the degradation of electrical parameters when high gate voltages and temperatures are applied and is especially observed during the ON-state operation of the transistor. By using MOS-HEMT structures with different gate dielectrics (SiO2, Al2O3, and AlN/Al2O3), the impact of the stress voltage, recovery voltage and temperature on the device reliability is analyzed including the role of oxide traps and the interface states to provide physical insights into this mechanism. The second phenomenon discussed in this thesis is the time-dependent dielectric breakdown (TDDB) observed on GET-SBDs during its OFF-operation. The percolation model and Weibull distribution are used to understand this degradation mechanism. As a result, it has been demonstrated that the time to breakdown tBD is influenced by the GET structure (single vs. double), the passivation thickness, the preclean process at the anode region before the GET dielectric deposition and the capping layer. Finally, by using 2D TCAD simulations, the long-term reliability improvement has been related to the reduction of the electric fie
University of Calabria
Hentschel, Rico. "Vertical Gallium Nitride Power Devices: Fabrication and Characterisation." 2020. https://tud.qucosa.de/id/qucosa%3A74885.
Повний текст джерелаBhoi, Kshirodra Kumar. "Performance Analysis of AlGaN/GaN HEMT and MOSHEMT Devices Towards Circuit Application." Thesis, 2018. http://ethesis.nitrkl.ac.in/10025/1/2018_MT_216EE1263_KKBhoi_Performance_Analysis_.pdf.
Повний текст джерелаShan, Li-Wei, and 單立偉. "Characterization study of high power GaN PIN devices grown on sapphire." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/h45ju3.
Повний текст джерела國立清華大學
電子工程研究所
107
In this study, MOCVD is used to grow GaN epitaxy layers on conventional sapphire substrate (CSS) and patterned Sapphire Substrate (PSS) of different size. Quasi-vertical GaN PIN diodes are made, edges of devices are protected by the PECVD grown SiO2 layer. After confirming the edge of the device is well-protected, characterization study is made. Study includes I-V, Ron (on resistance), C-V (capacitance-voltage), and DLTS measurement and analysis. The result shows that PSS is helpful to get a lower trap concentration in I-layer, and the size of PSS is also an important impact factor.
YU, CHENG-HSU, and 余政旭. "Design and Implementation of Totem-pole PFC with GaN Power Devices." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/zwxsd8.
Повний текст джерела國立臺北科技大學
電機工程系
107
The main theme of this thesis is design and implement a Totem-pole PFC with GaN power devices. The inducutor current is in continuous-conduction mode which is suitable for medium and high power application. The power device which is operated in high frequency requires or no less reverse recovery time to avoid short circuit and larger short-circuit current losses and even circuit damage. In this thesis, GaN power components are used, which has almost no reverse recovery current, thereby overcoming this problem. And use high frequency switch soft start technology to reduce the current spike, which occur at the zero cross point of input current. The specifications of the converter include: output power 800 W, input voltage 230 V/60 Hz, output voltage 380 VDC, switching frequency 100 kHz. Experimental results show: full load efficiency is 98.86 %, power factor is 0.974, and THDi is 6.921 %, the harmonics meet the requirement of IEC61000-3-2 Class A. By loss analysis, the total switching loss of high frequency switch is the highest.
Wang, Huan-Chung, and 王煥中. "Fabrication and Characterization of GaN-based Semiconductor Devices for High-Power and Microwave Power Applications." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/58nzjf.
Повний текст джерела國立交通大學
材料科學與工程學系所
107
Gallium nitride-based metal–insulator–semiconductor high electron mobility transistors (GaN MIS-HEMTs) are highly attractive for next-generation high-efficiency and high-voltage power applications. For the MIS-HEMT, dielectric materials play an important role in GaN-based heterojunction lateral devices as they are essential in surface passivation and gate stack. First, we improved the electrical performances of AlGaN/GaN MIS-HEMTs with high quality Al2O3 gate dielectric deposited by plasma enhanced atomic layer deposition (PEALD) using both H2O and remote O2 plasma as oxygen sources, indicating that incorporating remote O2 plasma in the ALD-Al2O3 deposition process is an effective and simple way to provide high quality gate dielectric. Then, we demonstrate the quaternary InAlGaN/GaN MIS-HEMTs with high quality SiNx gate dielectric and surface passivation layer deposited by low pressure chemical vapor deposition (LPCVD) at 780°C. The LPCVD-SiNx/InAlGaN/GaN MIS-HEMT device exhibited very high output current density, large gate voltage swing, low leakage current, high breakdown voltage, and low specific ON-resistance (RON,sp), yielding a high figure of merit (FOM) of 737 MW/cm^2. Furthermore, GaN-based HEMTs also have great potential in high power microwave applications owing to the superior material properties. We demonstrate the output power density at S-band for two different sizes of 0.2 mm and 1.2 mm AlGaN/GaN HEMTs on 4-inch SiC substrate.
Lin, Jhe-yu, and 林哲宇. "Using GaN Switching Devices for Common Mode EMI Reduction in Power Converters." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/wnxkgy.
Повний текст джерела國立臺灣大學
電機工程學研究所
105
The gallium nitride (GaN) cascode switch has received much attention recently for line-operated medium-high frequency (200 kHz to 500 kHz) applications. Because of its device structure, there are two package options available with regard to the tab internal connection; either the drain terminal or the source terminal is electrically connected to the metallic plate of the device package, unlike the conventional vertical power Si based MOSFET in which the drain terminal can be connected to the device metallic plate. It is proposed in the dissertation that taking advantage of the unique feature of GaN devices packages mentioned above and using a proper combination of the GaN devices in a converter circuit converter common mode noise can be reduced. As a result, the converter conducted EMI can be reduced. The theory is explained and the rule for proper package selection are described in the dissertertation. A 240-Watt LLC power converter with a front-end power-factor-correction (PFC) circuit was built for experimental verification. In the experiment, significant reduction in the conducted EMI was observed. The proposed strategy can be applied to other converter or inverter configurations. GaN devices provide an option, unavailable in power MOSFET devices to significantly reduce the converter conducted EMI.
Yueh, Wei-Lung, and 岳威龍. "The Study of GaN MIS-HEMT Power Device Instability and Electrical Reliability." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/r4b3ra.
Повний текст джерела國立交通大學
機械工程系所
107
Compared with the conventional silicon-based transistors, the AlGaN/GaN power transistor has the characteristics of high electron mobility and high breakdown voltage. , The AlGaN/GaN power transistor is also suitable for operation at high power and high frequency condition, and is one of the trends of semiconductors in the future. However, due to defects in the process and failure mechanism during operation, it is necessary to explore the reliability related issues and further improve performance of transistors effectively. There are many literatures on the reliability of traditional GaN-HEMTs, but the research on GaN MIS-HEMT (Metal-Insulator-Semiconductor High-IElectron-Mobility Transistor) has only gradually increased in recent years, while the reliability of traditional electronic power transistors It takes thousands of hours for the experiment to converge. Our laboratory has a considerable reliability study for GaN MIS-HEMT, and establishes a mathematical model for dynamic resistance (Dynamic RON) and life evaluation; therefore, this study will continue the experience of the predecessors, for the component's response performance and threshold voltage VTH (threshold voltage) offset and Gate-Lag effect on package device for more in-depth research. However, in the Gate-Lag experiment, a phenomenon was unintentionally discovered. When the pulse signal was used to measure the characteristic curve (pulse IV) of the package device, changing the pulse substrate caused a significant decrease in the channel current of the semiconductor device, and estimated it through various experiments. It exists in various semiconductors today, but it has not been found in the literature search. It is hereby established a chapter to explain the process of this phenomenon and compare it with commercially available device.
Tao, Tai-Ran, and 陶泰然. "The study of GaN MIS-HEMT power device with AlN stack layer." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/v574p3.
Повний текст джерела國立交通大學
國際半導體產業學院
107
In this thesis, a research of the application to the high power GaN metal-insulator-semiconductor HEMT (MIS-HEMT) was done. The result indicated that by using plasma enhanced ALD (PEALD) AlN as a stack layer deposition between oxide layer and semiconductor, the composite passivation structure could not only reach a higher current density, transconductance, and breakdown voltage, but also have the effect of suppressing leakage current and improving time-dependent dielectric breakdown (TDDB) reliability. We use ALD to deposit four kinds of passivation layer: Al2O3(12nm), HfO2(12nm), Al2O3+AlN(10+2nm), and HfO2+AlN(10+2nm), basing on the same AlGaN/GaN HEMTs epitaxial structure on Si, and we also discussed the difference between etching the passivation layer under the gate electrode or not. By comparing the DC characteristics, breakdown voltage, on-state and off-state leakage current ratio, CV measurement, and TDDB reliability between different passivation materials, we found that Al2O3 has the problem of insufficient effective dielectric constant, while HfO2 meets the difficulty in poor deposition quality. Both of the shortcomings could be traded-off by depositing a PEALD-AlN stack layer prior to the oxygen-related passivation, which is attributed to the quality improvement by nitrogen-related passivation effect and the high density positive fixed charges induced by PEALD-AlN.
Hong, Seung Jae. "Development of GaN-based power electronic devices using plasma-assisted molecular beam epitaxy /." 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3242872.
Повний текст джерелаSource: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6611. Adviser: Kyekyoon (Kevin) Kim. Includes bibliographical references (leaves 106-117) Available on microfilm from Pro Quest Information and Learning.
Wang, Chieh-An, and 王婕安. "Electro-Thermal Simulation and Heat Dissipation Analysis of Packaged GaN Power-HEMT Devices." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/80245632143150963673.
Повний текст джерела國立交通大學
機械工程系所
103
AlGaN/GaN high electron mobility transistors(HEMTs)are one of the prospective candidates for high switching frequency power electronics applications thanks to its wide band gap(3.4eV), high breakdown voltage, large critical electric field, high carrier mobility, and the inherent high speed characteristics. With the high power densities that AlGaN/GaN HEMTs are capable of reaching, heat dissipation is a crucial issue. This research presents an in depth thermal study of packaged GaN on Si power devices. The device is attached in a V-groove copper base, to enhance Si substrate thermal dissipation. The effects of structure design and fabrication processes on the device performance were studied. To improve the reliability and the performance of GaN power-HEMT devices, thermal management is one of the most critical aspects. Micro-Raman spectroscopy and Infrared(IR)thermography were used to identify temperature profiles and the hot spots of the devices. For the purpose of more precise temperature measurements, temperature vs. Raman shift curve fitting of experimental data of our device is illustrated. The measurements of longitudinal temperature have been acquired, so that the position of the hottest layer(2DEG)is realized. Then, Raman area temperature map measured over the lateral hottest layer depicted in this study. The comparison between Raman/IR experiment results and finite-element electro and thermal simulation has been shown.
Chang, Chi, and 張繼. "Research on GaN-based Power Devices Applied in Permanent Magnet Synchronous Motor Drive." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/763w44.
Повний текст джерела國立臺灣大學
工程科學及海洋工程學研究所
106
In this paper, wide-bandgap (WBG) gallium nitride (GaN)-based power devices were used to replace the traditional silicon power device to increase the switching speed of the power device and reduce the switching loss and conduction loss of the three-phase inverter. Therefore, we can use gallium nitride (GaN)-based power devices to increase the power conversion efficiency of the permanent magnet synchronous motor control system and improve the heat dissipation of the three-phase inverter. LTspice circuit simulation software were used to analyze the three-phase inverter circuits with traditional silicon power devices and gallium nitride (GaN) power devices. Gallium nitride (GaN) power devices can reduce switch on-time and switch-off time by 90%, and it also reduce the switching loss of 89% in the inverter when the load current is 8(A). By using MATLAB / Simulink, space vector pulse width modulation (SVPWM), vector control, permanent magnet synchronous machine (PMSM) and control system were combined to simulate the system response such as motor speed, voltage and current waveform of permanent magnet synchronous motor control system. We also use micro-control board and gallium nitride (GaN) power module to implement the permanent magnet synchronous motor control system. Verify that wide-bandgap (WBG) gallium nitride (GaN)-based power devices can be applied to the permanent magnet synchronous motor control system. We also compare the different between the GaN and Si motor control system. The GaN motor control system reduce the total power loss of 1440mW and up to 85.27% efficiency when the motor load is 0.2Nm. The GaN inverter also achieve 95.116% efficiency. Finally, the permanent magnet synchronous motor control system with higher switching speed and better power conversion efficiency is built.
Chen, Shi-Xuan, and 陳世軒. "The Study of GaN MIS-HEMT Power Device Electrical Reliability and Lifetime Evaluation." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/eckwzn.
Повний текст джерела國立交通大學
機械工程系所
106
AlGaN/GaN power transistor, compared to conventional silicon-based transistors, have characteristics of high electron mobility, high breakdown voltage, suitable for operating at high power and high frequency conditions. Due to the defects in the manufacturing process and the failure mechanism while the operation, it is necessary to discuss the reliability to improve the performance of the device effectively. If the buffer layer of the device is poorly insulated, some of the electrons can flow through the buffer layer to the Drain, the current which is not controlled by the Gate voltage is regarded as the leakage current. Therefore, the quality of buffer layer and the property of insulation would affect the cut-off characteristic of the device. It is known from the paper that GaN device will have Gate leakage current during operation and it would lead to the reduction of the efficiency. In order to reduce the leakage current, the device of this study insert the insulator (Si3N4) between the Gate and AlGaN layer to form MIS-HEMT (Metal-Insulator-Semiconductor High Electron Mobility Transistor) structure. In order to discuss the failure mechanism and structural degradation, this study defines the Critical Voltage as the voltage while the occurrence of significant electrical degradation. The 4-inch wafer was measured directly by probe station, and the electrical parameter were measured by Step-stress method, and the possibility and the reasons of failure mechanism will be defined. Additionally, the failure mechanism of Deep-Level-Transient of Dynamic-RON have been proposed by switch mode. The lifetime of the power transistor is also worth discussing, the lifetime evaluation and the choise of failure time, will use TDDB (time-dependent dielectric breakdown) method for the final step of the reliability experiment. Using the methods of statistics to analyze the data. The use of Weibull plot, curve fitting and other post-processing, can find the safely operating voltage for twenty years.
Hsu, Hao-Chiang, and 徐浩強. "Reliability and Transient Thermal Characteristics Analysis by Electrical Approach for GaN HEMTs Power Devices." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/98tbua.
Повний текст джерела國立交通大學
機械工程系所
105
The high power dissipation for AlGaN/GaN HEMT power device can result in a substantial self-heating effect on topside surface due to the lateral topologies, which will reduce the performance reliability. This paper proposes the fast static and transient thermal method which evaluates the thermal resistance constitution in the heat flow path. The method is based on the transient heating curve by the thermo-sensitive electrical parameters measurement for the cascode AlGaN/GaN HEMTs. The method is simple, non-invasive and not restricts by the device layout, package and geometry. With the help of structure function, the proposed process extracts the chip-level and junction to case thermal resistances. Furthermore, the thermal property of each package layer including contact thermal resistance is clearly shown in the graphical representation. This study also develops the short time transient measurement process which will tremendously reduce the measurement time comparing to the standard cooling curve method. Finally, the power cycle capability of Cascode GaN is investigated and use the structure function to reveal changes or failure in the thermal interface.
Tseng, Chien-Hua, and 曾建華. "High Power and High Gain Boost Converters in Comparison with GaN and MOS Devices." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/69208212110972472461.
Повний текст джерела輔仁大學
電機工程學系碩士在職專班
104
The thesis presents a technology that based on single-stage flyback converter with coupling inductance, switch-capacitor and diode-capacitor (DC) snubber. Using secondary side the transformer leakage inductance and secondary side DC snubber make to L-C series resonance for obtained the zero current switching and voltage clamped. Therefore this converter can increase at least five times voltage gains. Moreover, the total output power can increase and reduce ripple by using the interleaved converter method for four phase module. Also , this thesis presents the analysis of power semiconductor devices, components selection, transformer design and magnetic flux density calculation for the proposed converters. This can use material properties to achieve good performance, reduce PCB board size, save cost and achieve the best performance of converter. Finally, simulation and experimental results are employed to verify feasibility of the proposed converter under the different devices.
"Particle-Based Modeling of Reliability for Millimeter-Wave GaN Devices for Power Amplifier Applications." Doctoral diss., 2018. http://hdl.handle.net/2286/R.I.49331.
Повний текст джерелаDissertation/Thesis
Doctoral Dissertation Electrical Engineering 2018
Tsou, Chuan Wei, and 鄒權煒. "GaN-Based Devices on Silicon Substrate with Schottky Extension for High Power and RF Applications." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/q237ry.
Повний текст джерелаChang, Chia-Ta, and 張家達. "Fabrication and Characterization of GaN-based Semiconductor Devices for High Frequency and High Power Applications." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/59417888525137740170.
Повний текст джерела國立交通大學
材料科學與工程學系
99
GaN-based semiconductors are promising candidates for RF high frequency wireless, power electronics, and optoelectronics applications. This thesis focuses GaN-based High Electron Mobility Transistors (HEMTs) for high frequency and high power application. First of all, the characteristics of unpassivated AlGaN/GaN HEMTs under uniaxial tensile strain were investigated. Mechanical stress can produce additional charges resulting in the change of HEMT channel current. This phenomenon depends on gate orientation, and may be the result of the piezoelectric effect and changes in electron mobility due to the applied uniaxial stress. Additionally, results show that tensile strain reduces the transient current, which is likely due to the additional donor-like surface states created through the piezoelectric effect. Secondly, a 100-nm gate-recessed n-GaN/AlGaN/GaN HEMT with low noise properties at 30 GHz is demonstrated. The recessed GaN HEMT exhibits a low ohmic-contact resistance of 0.28?n?!!!@#8226;mm, and a low gate leakage current of 0.9 μA/mm when biased at VGS = −3 V and VDS = 10 V. At the same bias point, a minimum noise figure of 1.6 dB at 30 GHz and an associated gain of 5dB are achieved. To the best of our knowledge, this is the first and the best noise performance reported at 30 GHz for gate-recessed AlGaN/GaN HEMTs. Finally, a normally-off operation AlGaN/GaN HEMT with high threshold voltage is developed utilizing a Fluorine-based treatment technique combined with a metal-oxide-semiconductor gate architecture. Threshold voltage as high as 5.1 V was achieved using a 16-nm-thick Al2O3 gate oxide film. Additionally, the device performed a drain current density of 500 mA/mm and a peak transconductance of 100 mS/mm. These performances are comparable to the conventional normally-on devices.
Chang, Hao-Ming, and 張皓敏. "The characterization of AlGaN / GaN high-power transistor device structure in SiC and Si substrate." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/27078564942347333047.
Повний текст джерела中華大學
電機工程學系碩士班
99
In recent years, with the public demand for wireless products is growing, thus creating a high-power semiconductor device on the required output is also higher, although the traditional substrate materials have a process to produce cheap price stability and overall advantages of total . However, the elements subject to their own characteristics, the performance is not high-power family of elements with a few components compared to the material which is currently popular AlGaN / GaN transistors formed. GaN has a high power, high temperature, high breakdown voltage, high current density, high-frequency characteristics of good performance, wireless transmission products now required for high-power amplifier has great appeal. GaN transistors in the substrate self-heating caused by poor heat dissipation problems, resulting in reduced transistor performance. GaN transistors with different substrate materials such as SiC, Si, Sapphire for the combination can improve the heat dissipation and have different performance characteristics. The advantage of SiC substrate using a high heat capacity, the thermal conductivity of 4.9 W / cm K is three time for the GaN (1.5W/cm K). The temperature can up to 400°C or more. However, SiC substrates is too expensive. The silicon substrate is good candidate for GaN transistors due to its low cost, large area and high electrical conductivity (heat). GaN transistors with high-power, High temperature, high breakdown voltage and high current density on different substrate can further develop high efficiency, large area, low cost devices in the next generation. In this thesis, we used SiC and Si substrate to study the selft heating effect of GaN. Pulse IV and Load Pull measurements also be used to analysis the self heating effect and electrical degradation of GaN devices.
Hsieh, Ting-En, and 謝廷恩. "Fabrication and Characterization of GaN-based Semiconductor Devices on Si Substrates for High-Power Electronic Applications." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/17580540732119249671.
Повний текст джерела國立交通大學
材料科學與工程學系所
104
The integration of GaN-based High Electron Mobility Transistors (HEMTs) and a large diameter Si substrate are promising candidates for next-generation high power device applications owing to the high current, high breakdown, and low fabrication cost. This thesis focuses GaN-based HEMTs on Si with low current collapse by high quality gate insulator and development of gold free gate structure with high thermal stability. First of all, the stable electrical properties of Al2O3/AlN/AlGaN/GaN metal-insulator-semiconductor (MIS-HEMTs) by using an Al2O3/AlN stack layer as the gate insulator layer were investigated. The device exhibits a small threshold voltage hysteresis of ~200mV. Additionally, no obvious changes in the drain current were observed for the device during the drain voltage stress of 100V for 15 h. Secondly, a gate recessed normally-OFF Al2O3/AlN/AlGaN/GaN MIS-HEMT with low threshold voltage hysteresis is demonstrated. The device exhibits a threshold voltage of +1.5 V, with current density of 420mA/mm, an OFF-state breakdown voltage of 600V and high ON/OFF drain current ratio of ~109. Finally, a GaN HEMT with WNX/Cu gate for high power application is developed. The direct current (DC) characteristics of the device are comparable to a conventional Ni/Au gated GaN HEMT. The results of a high voltage stress test indicated that the device was stable after 200 V stress was applied for 42 hours. Additionally, the WNX/Cu gated GaN HEMTs exhibits no obvious change for DC characteristics and Schottky barrier height before and after 2500C annealing for 1 hour.
Chin, Ping-Chieh, and 金秉頡. "The Study of AlGaN/GaN HEMT Power Device Characteristics and Reliability Improvement Using Field Plate Approach." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/19585192913775694876.
Повний текст джерела國立交通大學
光電系統研究所
103
GaN has high mobility, high breakdown and low on-resistance, comparing with other electron device. It is more suitable for high power application. However, GaN is a piezoelectric material. It would create an inverse piezoelectric effect, which lead to current degradation further. This study applies a field plate structure to enhance the electric characteristics and reliability of device. DC measurement results are used to compare with conventional device. The results indicated that the field-plate HEMT has higher breakdown voltage, better threshold voltage Vth). It successfully reduced the current degradation and exhibited stable dynamic on-resistance (Ron). Besides, the small signal equivalent circuits are used to extract variation of the intrinsic capacitance. It can prove the mechanism of current degradation and reliability. These results would help solve the problem of current degradation in GaN high power devices.