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dc.contributor.advisorTutuc, Emanuel, 1974-en
dc.creatorDillen, David Carlen
dc.date.accessioned2011-09-30T19:19:21Zen
dc.date.available2011-09-30T19:19:21Zen
dc.date.issued2011-08en
dc.date.submittedAugust 2011en
dc.identifier.urihttp://hdl.handle.net/2152/ETD-UT-2011-08-4360en
dc.descriptiontexten
dc.description.abstractSemiconductor nanowire field-effect transistors (NWFET) have been recognized as a possible alternative to silicon-based CMOS technology as traditional scaling limits are neared. The core-shell nanowire structure, in particular, also allows for the enhancement of carrier mobility through radial band engineering. In this thesis, we have evaluated the possibility of electron confinement in strained Si-Si1-xGex core-shell nanowire heterostructures. Cylindrical strain distribution was calculated analytically for structures of various dimensions and shell compositions. The strain-induced conduction band edge shift of each region was found using k•p theory coupled with a coordinate system shift to account for strain. A positive conduction band offset of up to 200 meV was found for a Si-Si0.2Ge0.8 structure. We have also designed and characterized a modulation doping scheme for p-type, Ge-SiGe core-shell NWFETs. Finite element simulations of hole density versus radial position were done for different combinations of dopant position and concentration. Three modulation doped nanowire samples, each with a different boron doping density in the shell, were grown using a combined vapor-liquid-solid and chemical vapor deposition process. Low temperature current-voltage measurements of bottom- and top-gate samples indicate that hole mobility is limited by the proximity of charged impurities.en
dc.format.mimetypeapplication/pdfen
dc.language.isoengen
dc.subjectCore-shellen
dc.subjectNanowireen
dc.subjectStrained heterostructureen
dc.subjectModulation-dopingen
dc.titleConfined electron systems in Si-Ge nanowire heterostructuresen
dc.date.updated2011-09-30T19:19:33Zen
dc.identifier.slug2152/ETD-UT-2011-08-4360en
dc.contributor.committeeMemberBanerjee, Sanjay K.en
dc.description.departmentElectrical and Computer Engineeringen
dc.type.genrethesisen
thesis.degree.departmentElectrical and Computer Engineeringen
thesis.degree.disciplineElectrical and Computer Engineeringen
thesis.degree.grantorUniversity of Texas at Austinen
thesis.degree.levelMastersen
thesis.degree.nameMaster of Science in Engineeringen


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