Tesis sobre el tema "Silicon carbide"
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte los 50 mejores tesis para su investigación sobre el tema "Silicon carbide".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Explore tesis sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.
Wang, Jue. "Silicon carbide power devices". Thesis, Heriot-Watt University, 2000. http://hdl.handle.net/10399/579.
Texto completoFuentes, Ricardo I. "Sintering of silicon carbide". Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/14208.
Texto completoVita.
Includes bibliographical references (leaves 152-159).
by Ricardo I Fuentes.
Ph.D.
Pehlivanoglu, Ibrahim Engin. "SILICON CARBIDE MEMS OSCILLATOR". Case Western Reserve University School of Graduate Studies / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=case1196372276.
Texto completoPellegrino, Paolo. "Point Defects in Silicon and Silicon-Carbide". Doctoral thesis, KTH, Microelectronics and Information Technology, IMIT, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3133.
Texto completoRazzell, Anthony Gordon. "Silicon carbide fibre silicon nitride matrix composites". Thesis, University of Warwick, 1992. http://wrap.warwick.ac.uk/110559/.
Texto completoGao, Wei. "Oxidation of nitride-bonded silicon carbide (NBSC) and hot rod silicon carbide with coatings". Thesis, University of Strathclyde, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366751.
Texto completoAnthony, Carl John. "Oxide interface studies on silicon and silicon carbide". Thesis, University of Newcastle Upon Tyne, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.424150.
Texto completoGodard, Hilary Tony. "Aspects of the silicon carbide filament - silicon interface /". The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487322984313654.
Texto completoWu, Huann-Der. "Vapor synthesis of silicon and silicon carbide powders /". The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487330761217513.
Texto completoIwata, Hisaomi. "Stacking faults in silicon carbide /". Linköping : Univ, 2003. http://www.bibl.liu.se/liupubl/disp/disp2003/tek817s.pdf.
Texto completoDusatko, Tomas A. "Silicon carbide RF-MEM resonators". Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100250.
Texto completoSeveral different clamped-clamped beam resonator designs were successfully fabricated and tested using a custom built vacuum system, with measured frequencies ranging from 5MHz to 25MHz. A novel thermal tuning method is also demonstrated, using integrated heaters directly on the resonant structure to exploit the temperature dependence of the Young's modulus and thermally induced stresses.
Pedersen, Henrik. "Chloride-based Silicon Carbide CVD". Doctoral thesis, Linköpings universitet, Materiefysik, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-15428.
Texto completoKiselkarbid (SiC) är ett fascinerande material som samtidigt är mycket enkelt och mycketkomplicerat. Det är enkelt eftersom det byggs upp av bara två sorters atomer, kisel och kol.Atomerna bygger upp kristallens struktur genom att bilda Si-C bindningar och man kan beskrivakristallstrukturen som uppbyggd av tetraedrar med en kiselatom (eller kolatom) i mitten och enkolatom (eller kiselatom) i varje hörn på tetraedern. Samtidigt är SiC komplicerat eftersomberoende på hur man staplar dessa tetraedrar kan man få olika varianter på kristallstrukturen, såkallade polytyper. Det finns drygt 200 kända polytyper av kiselkarbid, men det är dock bara enhandfull av dessa polytyper som är tekniskt intressanta. Kiselkarbid är intressant eftersom det ärett hårt material som inte heller påverkas nämnvärt av kemiskt aggressiva miljöer ellertemperaturer upp till 2000 °C; dessutom är SiC en halvledare och tack vare dess tålighet är det ettmycket bra material för elektriska komponenter för högspänningselektronik eller för användningi aggressiva miljöer. För att kunna tillverka dessa komponenter måste man kunna odla kristaller av kiselkarbid. Detfinns i princip två typer av kristallodling; i) odling av bulkkristaller, där stora kristaller odlas föratt sedan kan skivas och poleras till kristallskivor (dessa skivor benämns oftast substrat), och ii)odling av epitaxiella skikt, där man odlar ett tunt lager kristall med mycket hög renhet ovanpå ettsubstrat (ordet epitaxi kommer från grekiskans epi = ovanpå och taxis = i ordning, epitaxiellaskikt odlas alltså ovanpå ett substrat och kopierar den kristallina ordningen hos substratet). I detepitaxiella skiktet, eller epilagret som det även kallas, kan man styra den elektriskaledningsförmågan med mycket hög precision genom att blanda in små mängder orenheter iepilagret, man pratar här om att dopa halvledarkristallen. För att odla epilager av SiC använderman CVD, CVD betyder Chemical Vapor Deposition, någon riktigt bra svensk översättningfinns inte men det är en teknik för att framställa ett tunt lager av ett material genom kemiskareaktioner med gaser som startmaterial. I standard CVD-processen för odling av SiC epilager använder man silan (SiH4) som kiselkälla och lätta kolväten som eten (C2H4) eller propan (C3H8) som kolkälla. Dessa gaser späds kraftigtut i vätgas och man odlar epilagret vid ungefär 1500-1600 °C. Med denna process kan man odlaca 5 mikrometer (mikrometer = miljondelsmeter) epilager på en timme. Men för vissakomponenter behöver man ett epilager som är över 100 mikrometer tjockt, vilket görtillverkningen av sådana komponenter både tidsödande och kostsam. Ett problem som manmåste lösa för att få högre tillväxthastighet i processen är att när man ökar mängden silan,kommer kiseldroppar att bildas i gasfasen och om de kommer i kontakt med substratet blirepilagret förstört. I denna avhandling undersöks ett sätt att lösa problemet med kiseldropparnaoch därmed kunna tillåta höga tillväxthastigheter för SiC epilager. Idén är att man kan lösa uppkiseldropparna genom att tillsätta något i gasblandningen som binder starkare till kisel än kisel.En mycket bra atom att använda för detta ändamål är klor eftersom klor binder mycket starkt tillkisel. Man kallar denna process för klorid-baserad CVD. Till att börja med använde vi molekylen metyltriklorsilan (MTS), som innehåller både kol, kiseloch klor, för klorid-baserad tillväxt av SiC epilager. Genom att använda MTS lyckades vi fåtillväxthastigheter mellan 2 och 104 mikrometer i timmen. Vi har även visat att det är möjligtanvända MTS för att odla 200 mikrometer tjocka epilager med en tillväxthastighet på 100mikrometer i timmen utan att den kristallina kvalitén på epilagren försämras. Ett alternativ till attanvända MTS är att addera saltsyra (HCl) i gasform till standard processen. För att förstå denklorid-baserade processen bättre, jämfördes de olika alternativen med litteraturdata från enprocess där man istället för vanlig silan hade använt triklorsilan (TCS) för att få en klorid-baserad process. Det visade sig att MTS- och TCS-processerna krävde mindre kiselhalt i gasfasen för attfå en hög tillväxthastighet, med andra ord var de mer effektiva. Vi förklarade detta med atteftersom dessa startmolekyler har tre kisel-kol bindningar är det enkelt att bilda SiCl2 molekylen,som har visat sig vara ett viktigt mellansteg i den klorid-baserade processen, eftersom man dåbara behöver bryta kemiska bindningar. Om man istället börjar från silan och saltsyra måstekemiska reaktioner ske för att skapa kisel-kol bindningar och därmed SiCl2. När man odlar kristaller underlättar man tillväxten genom att preparera ytan på substratet medatomära steg. Om man tittar på ytan med atomär förstoring kan säga att ytan liknar en trappa,detta är bra eftersom atomerna som bygger upp epilagret gärna fastnar vid atomära steg eftersomde kan binda in till kristallen både neråt och åt sidan. Vi har optimerat standard processen för attfå bättre morfologi, alltså en finare yta, när man odlar på substrat som har mindre andel atomärasteg på ytan och visat att denna optimering går att överföra till en klorid-baserad process medhög tillväxthastighet . Vi har även visat att man kan använda den klorid-baserade processen föratt odla epilager med hög tillväxthastighet på substrat helt utan atomära steg. Slutligen har vi studerat doping av kiselkarbid vid höga tillväxthastigheter med den kloridbaseradeprocessen, både n-typ doping (där man dopar med ämnen som har fler valenselektronerän kol och kisel så att man får ett överskott av elektroner i materialet) med kväve och fosfor, ochp-typ doping (där man dopar med ämnen som har färre valenselektroner än kol och kisel så attman får ett underskott av elektroner i materialet) med bor och aluminium.
Lee, Te-Hao. "Silicon Carbide High Temperature Logic". Case Western Reserve University School of Graduate Studies / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=case1283437983.
Texto completoShih, Chienchung James. "Dynamic deformation of silicon carbide /". Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1998. http://wwwlib.umi.com/cr/ucsd/fullcit?p9824655.
Texto completoPowell, Keith Neil. "Integrated Photonics in Silicon Carbide". Thesis, The University of Sydney, 2022. https://hdl.handle.net/2123/29620.
Texto completoNorén, Olof. "Epitaxial and bulk growth of cubic silicon carbide on off-oriented 4H-silicon carbide substrates". Thesis, Linköpings universitet, Halvledarmaterial, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-121637.
Texto completoMartinelli, Antonio Eduardo. "Diffusion bonding of silicon carbide and silicone nitride to molybdenum". Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=40191.
Texto completoSiC was solid-state bonded to Mo at temperatures ranging from 1000$ sp circ$C to 1700$ sp circ$C. Diffusion of Si and C into Mo resulted in a reaction layer containing two main phases: $ rm Mo sb5Si sb3$ and Mo$ sb2$C. At temperatures higher than 1400$ sp circ$C diffusion of C into $ rm Mo sb5Si sb3$ stabilized a ternary phase of composition $ rm Mo sb5Si sb3$C. At 1700$ sp circ$C, the formation of MoC$ rm sb{1-x}$ was observed as a consequence of bulk diffusion of C into Mo$ sb2$C. A maximum average shear strength of 50 MPa was obtained for samples hot-pressed at 1400$ sp circ$C for 1 hour. Higher temperatures and longer times contributed to a reduction in the shear strength of the joints, due to the excessive growth of the interfacial reaction layer. $ rm Si sb3N sb4$ was joined to Mo in vacuum and nitrogen, at temperatures between 1000$ sp circ$C and 1800$ sp circ$C, for times varying from 15 minutes to 4 hours. Dissociation of $ rm Si sb3N sb4$ and diffusion of Si into Mo resulted in the formation of a reaction layer consisting, initially, of $ rm Mo sb3$Si. At 1600$ sp circ$C (in vacuum) Mo$ sb3$Si was partially transformed into $ rm Mo sb5Si sb3$ by diffusion of Si into the original silicide, and at higher temperatures, this transformation progressed extensively within the reaction zone. Residual N$ sb2$ gas, which originated from the decomposition of $ rm Si sb3N sb4,$ dissolved in the Mo, however, most of the gas escaped during bonding or remained trapped at the original $ rm Si sb3N sb4$-Mo interface, resulting in the formation of a porous layer. Joining in N$ sb2$ increased the stability of $ rm Si sb3N sb4,$ affecting the kinetics of the diffusion bonding process. The bonding environment did not affect the composition and morphology of the interfaces for the partial pressures of N$ sb2$ used. A maximum average shear strength of 57 MPa was obtained for samples hot-pressed in vacuum at 1400$ sp circ$C for 1 hour.
Tatli, Zafer. "Silicon nitride and silicon carbide fabrication using coated powders". Thesis, University of Newcastle Upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394640.
Texto completoToal, Shane J. "Nanocrystalline silicon carbide growth on silicon using ECR-PACVD". Thesis, London South Bank University, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434446.
Texto completoNichtawitz, Anthony. "Thermal conductivity of reaction-infiltrated silicon-silicon carbide composites". Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/41399.
Texto completoTuran, Servet. "Microstructural characterisation of silicon nitride-silicon carbide particulate composites". Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627653.
Texto completoColclough, Anthony Finbar. "The indentation and erosion behaviour of a silicon carbide and a silicon carbide-titanium diboride composite". Thesis, University of Surrey, 1994. http://epubs.surrey.ac.uk/843564/.
Texto completoSwanson, Kyle. "Epitaxial growth of silicon carbide on on-axis silicon carbide substrates using methyltrichlorosilane chemical vapor deposition". Thesis, Manhattan, Kan. : Kansas State University, 2008. http://hdl.handle.net/2097/719.
Texto completoJackson, Stacey Michael. "Optical characterisation of cubic silicon carbide". Thesis, University of Surrey, 1998. http://epubs.surrey.ac.uk/842961/.
Texto completoBrennan, Daniel Richard. "Silicon carbide technology for extreme environments". Thesis, University of Newcastle upon Tyne, 2016. http://hdl.handle.net/10443/3154.
Texto completoFerro, Alberto Eduardo Morao Cabral. "Aluminium brazes for silicon carbide ceramics". Thesis, University of Oxford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317212.
Texto completoBlackwood, I. P. "Investigation of nickel-silicon carbide formation". Thesis, Swansea University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636108.
Texto completoJiang, H. "Tensile creep of sintered silicon carbide". Thesis, Swansea University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.637429.
Texto completoCranstone, Wayne Robert Ian. "The fabrication of silicon carbide fibres". Thesis, University of Sheffield, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296812.
Texto completoMacLean, Heather J. (Heather Jean) 1974. "Silver transport in CVD silicon carbide". Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/17745.
Texto completoIncludes bibliographical references.
Ion implantation and diffusion couple experiments were used to study silver transport through and release from CVD silicon carbide. Results of these experiments show that silver does not migrate via classical diffusion in silicon carbide. Silver release is, however, likely dominated by vapor transport through cracks in SiC coatings. The results of silver ion implantation in silicon carbide and subsequent annealing at 1500ʻC place an upper limit on the silver diffusion coefficient in SiC of 5x10-21 m2/s, a value which is roughly 6 orders of magnitude less than the previous values reported in the literature. Silver diffusion should have been easily observable, but was not detected in SiC plates after heat treatments at 1500ʻC for times ranging between 200 h and 500 h. A detailed investigation of the silver morphology within the SiC both before and after heating showed that silver was immobilized at SiC grain boundaries and did not diffuse along them as expected. Novel spherical diffusion couples were fabricated containing silver inside shells of either graphite or SiC which were coated with CVD SiC. Mass measurements clearly revealed silver release from the diffusion couples after heating, but no silver was detected during concentration profile measurements in the SiC. Leak testing results, however, gave evidence of the presence of cracks in many of the SiC coatings, which may have provided pathways for silver escape. A simple vapor flow model was applied to estimate crack sizes that would account for silver release from SiC coatings in the current diffusion couples and coated fuel particle tests from the literature.
(cont.) These calculated crack sizes are small enough that they would not have been detected during normal investigation or post-irradiation examination. A diffusive mechanism has been assumed to control silver transport in silicon carbide based on silver release observations reported previously in the literature, but no direct evidence of silver diffusion has been offered. Additionally, variations in silver release from particle to particle indicate that silver transport does not occur equally in all silicon carbide samples and is not consistent with diffusion. The findings presented in this dissertation are important to coated particle fuel design and fabrication because they indicate that SiC can successfully retain silver but that some SiC coatings permit silver release. Future work must be directed at identifying the pathways for silver release and their root causes in order to prevent silver release from coated fuel particles.
by Heather J. MacLean.
Ph.D.
Habib, Hassan. "Complementary JFET logic in silicon carbide". Thesis, University of Newcastle upon Tyne, 2013. http://hdl.handle.net/10443/2233.
Texto completoBesnard, Cyril. "Silicon doped boron carbide for armour". Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/54830.
Texto completoKarbovnyk, I., P. Savchyn, A. I. Popov, A. Huczko, M. C. Guidi y Ch Mirri. "Infrared characterization of silicon carbide nanowires". Thesis, Sumy State University, 2011. http://essuir.sumdu.edu.ua/handle/123456789/20632.
Texto completoNing, Xian Jie. "TEM study of silicon carbide fibers". Case Western Reserve University School of Graduate Studies / OhioLINK, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=case1056400648.
Texto completoJanz, Stefan. "Amorphous Silicon Carbide for Photovoltaic Applications". [S.l. : s.n.], 2006. http://nbn-resolving.de/urn:nbn:de:bsz:352-opus-32019.
Texto completoDe, Genua Francesca. "Engineered Alumina / Silicon Carbide Laminated Composites". Doctoral thesis, Università degli studi di Trento, 2014. https://hdl.handle.net/11572/368173.
Texto completoDe, Genua Francesca. "Engineered Alumina / Silicon Carbide Laminated Composites". Doctoral thesis, University of Trento, 2014. http://eprints-phd.biblio.unitn.it/1219/1/PhD_Thesis_DE_GENUA_FRANCESCA.pdf.
Texto completoKortegaard, Nielsen Hanne. "Capacitance transient measurements on point defects in silicon and silicol carbide". Doctoral thesis, KTH, Microelectronics and Information Technology, IMIT, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-211.
Texto completoElectrically active point defects in semiconductor materials are important because they strongly affect material properties like effective doping concentration and charge carrier lifetimes. This thesis presents results on point defects introduced by ion implantation in silicon and silicon carbide. The defects have mainly been studied by deep level transient spectroscopy (DLTS) which is a quantitative, electrical characterization method highly suitable for point defect studies. The method is based on measurements of capacitance transients and both standard DLTS and new applications of the technique have been used.
In silicon, a fundamental understanding of diffusion phenomena, like room-temperature migration of point defects and transient enhanced diffusion (TED), is still incomplete. This thesis presents new results which brings this understanding a step closer. In the implantation-based experimental method used to measure point defect migration at room temperature, it has been difficult to separate the effects of defect migration and ion channeling. For various reasons, the effect of channeling has so far been disregarded in this type of experiments. Here, a very simple method to assess the amount of channeling is presented, and it is shown that channeling dominates in our experiments. It is therefore recommended that this simple test for channeling is included in all such experiments. This thesis also contains a detailed experimental study on the defect distributions of vacancy and interstitial related damage in ion implanted silicon. Experiments show that interstitial related damage is positioned deeper (0.4 um or more) than vacancy related damage. A physical model to explain this is presented. This study is important to the future modeling of transient enhanced diffusion.
Furthermore, the point defect evolution in low-fluence implanted 4H-SiC is investigated, and a large number of new defect levels has been observed. Many of these levels change or anneal out at temperatures below 300 C, which is not in accordance with the general belief that point defect diffusion in SiC requires high temperatures. This thesis also includes an extensive study on a metastable defect which we have observed for the first time and labeled the M-center. The defect is characterized with respect to DLTS signatures, reconfiguration barriers, kinetics and temperature interval for annealing, carrier capture cross sections, and charge state identification. A detailed configuration diagram for the M-center is presented.
Åberg, Denny. "Capacitance Spectroscopy of Point Defects in Silicon and Silicon Carbide". Doctoral thesis, KTH, Microelectronics and Information Technology, IMIT, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3205.
Texto completoWhipple, Steven G. "Fabrication and characterization of hybrid silicon-on-silicon carbide wafers". Diss., Connect to online resource, 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:3219025.
Texto completoSimner, Steven Philip. "The reaction bonding of silicon carbide using alloyed silicon infiltrants". Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670249.
Texto completoYang, Nanying. "Characterization and modeling of silicon and silicon carbide power devices". Diss., Virginia Tech, 2010. http://hdl.handle.net/10919/29643.
Texto completoPh. D.
Kim, Hyoun-Ee. "Gaseous corrosion of silicon carbide and silicon nitride in hydrogen /". The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487327695622538.
Texto completoWilliams, T. "Development Of pressureless sintered silicon carbide-boron carbide composites for armour applications". Thesis, University of Surrey, 2016. http://epubs.surrey.ac.uk/810348/.
Texto completoRaghavan, Srikanth. "Comparative studies of 6H-SiC surface preparation". Morgantown, W. Va. : [West Virginia University Libraries], 2008. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5766.
Texto completoTitle from document title page. Document formatted into pages; contains xii, 56 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 51-53).
Choudhury, Arnab. "Process development for a silicon carbide micro four-point probe". Thesis, Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04082004-180116/unrestricted/choudhury%5Farnab%5F200312%5Fms.pdf.
Texto completoRurali, Riccardo. "Theoretical studies of defects in silicon carbide". Doctoral thesis, Universitat Autònoma de Barcelona, 2003. http://hdl.handle.net/10803/3355.
Texto completoEl proceso de transient enhanced diffusion del boro ha sido estudiado y se ha propuesto una descripción microscópica del mismo: el kick-out realizado por un auto-intersticial de silicio cercano ha resultado ser el responsable de la metaestabilidad del de otra forma altamente estable boro sustitucional.
El mecanismo de difusión de la vacante de carbono y de silicio ha sido discutido y caracterizado; se ha demostrado que la vacante de carbono migra solamente a través de un mecanismo de difusión a los segundos vecinos, mientras que la vacante de silicio es metaestable con respecto a la formación del par vacante-antisito y entonces el camino de difusión será mediado por la formación de dicha configuración.
El dopaje de tipo n en las condiciones de alta dosis obtenidas con nitrógeno y/o fósforo ha sido estudiado; se ha mostrado que la formación de complejos de nitrógenos eléctricamente inactivos hace que el fósforo sea la elección mas adecuada para obtener dopaje de tipo n bajo estas condiciones.
Electronic structure calculations have been used to study the structure, the diffusivity and the electrical activity of point defects in silicon carbide. Particularly, p-type and n-type impurities have been considered, namely boron, nitrogen and phosphorus, together with intrinsic defects, specifically vacancies of the host crystal.
The transient enhanced diffusion of boron have been approached and a microscopic picture of this process have been proposed; the kick-out operated by a nearby silicon self-interstitial have turned out to be the responsible of the induced metastability of the otherwise highly stable boron substitutional.
The diffusion mechanism of the carbon and the silicon vacancy have been discussed and characterised; it has been shown that the carbon vacancy can only migrate by means of a second neighbour diffusion mechanisms, while the silicon vacancy is metastable with respect to the formation of a vacancy-antisite pair, and therefore the diffusion path will be mediated by the formation of such configuration.
The n-type high-dose doping regime obtained with nitrogen and / or phosphorus have been studied; it has been demonstrated that the formation of electrically inactive nitrogen aggregate in the high-dose regime makes phosphorus the preferred choice to achieve n-type doping under such conditions.
Dahlquist, Fanny. "Junction Barrier Schottky Rectifiers in Silicon Carbide". Doctoral thesis, KTH, Microelectronics and Information Technology, IMIT, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3367.
Texto completoWolborski, Maciej. "Termination and passivation of Silicon Carbide Devices". Licentiate thesis, KTH, Microelectronics and Information Technology, IMIT, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-439.
Texto completoSilicon carbide rectifiers are commercially available since 2001, and MESFET switches are expected to enter the market within a year. Moreover, three inch SiC wafers can be purchased nowadays without critical defects for the device performance and four inch substrate wafers are announced for the year 2005. Despite this tremendous development in SiC technology, the reliability issues like device degradation or high channel mobility still remain to be solved.
This thesis focuses on SiC surface passivation and termination, a topic which is very important for the utilisation of the full potential of this semiconductor. Three dielectrics with high dielectric constants, Al2O3, AlN and TiO2, were deposited on SiC with different techniques. The structural and electrical properties of the dielectrics were measured and the best insulating layers were then deposited on fully processed and well characterised 1.2 kV 4H SiC PiN diodes. For the best Al2O3 layers, the leakage current was reduced to half its value and the breakdown voltage was extended by 0.5 kV, reaching 1.6 kV, compared to non passivated devices.
As important as the proper choice of dielectric material is a proper surface preparation prior to deposition of the insulator. In the thesis two surface treatments were tested, a standard HF termination used in silicon technology and an exposure to UV light from a mercury lamp. The second technique is highly interesting since a substantial improvement was observed when UV light was used prior to the dielectric deposition. Moreover, UV light stabilized the surface and reduced the leakage current by a factor of 100 for SiC devices after 10 Mrad γ ray exposition. The experiments indicate also that the measured leakage currents of the order of pA are dominated by surface leakage.
Ndzane, Nolufefe Muriel. "Electron microscopy characterisation of polycrystalline silicon carbide". Thesis, Nelson Mandela Metropolitan University, 2014. http://hdl.handle.net/10948/d1020634.
Texto completo