Regensburg 2004 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 40: SiC I
HL 40.1: Vortrag
Donnerstag, 11. März 2004, 15:15–15:30, H15
Homoepitaxial growth of 4H-SiC:Ge alloys on 4H-SiC (0001) substrates by Molecular Beam Epitaxy — •Petia Weih1, Thomas Stauden1, Lothar Spieß2, Henry Romanus2, Oliver Ambacher1, and Jörg Pezoldt1 — 1FG Nanotechnologie, Zentrum für Mikro- und Nanotechnologien, TU Ilmenau, PF100565, D-98693 Ilmenau, Germany — 2FG Werkstofftechnologie, Zentrum für Mikro- und Nanotechnologien, TU Ilmenau, PF100565, D-98693 Ilmenau, Germany
Up to date the only intrinsic heterostructures based on SiC are beta-SiC/alpha-SiC heterojunctions using different bandgaps of different polytypes, which could not be improved into commercial applications because of unsolved technological problems. The epitaxy of SiC:Ge alloys provides the opportunity of bandgap engineering and the realization of alternative SiC based heterostructures. The draw backs of SiC:Ge alloys are the thermodynamic instability and the immiscibility of Ge in SiC, which must be overcome by nonequilibrium material synthesis methods such as ion beam synthesis or molecular beam epitaxy. In this work for the first time SiC:Ge thin films were grown homoepitaxially by solid source molecular beam epitaxy applying (a) continuous fluxes of Si-, C- and Ge- flux or (b) atomic layer epitaxy (subsequent deposition of C and Si/Ge) on on-axis 4H-SiC (0001) substrates. The surface morphology, the chemical composition and the structure of the grown layers were analysed by atom force microscopy, scanning electron microscopy with accompanying energy dispersive X-ray analysis, secondary ion mass spectroscopy and transmission electron microscopy, respectively.