Berlin 2005 – scientific programme

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HL: Halbleiterphysik

HL 58: Poster IIb

HL 58.64: Poster

Tuesday, March 8, 2005, 16:30–19:00, Poster TU F

Size Reduction of Silicon / Silicon Dioxide Nanowires — •Florian M. Kolb, Herbert Hofmeister, Margit Zacharias, and Ulrich Gösele — Max-Planck-Institut für Mikrostrukturphysik, 06120 Halle (Saale)

Nanowires consisting of a crystalline silicon core and an amorphous silicon dioxide shell can be obtained by combining thermal evaporation of silicon monoxide with the vapor-liquid-solid (VLS) process. The resulting nanowires show silicon core diameters between 15 nm and 75 nm and lengths up to several micrometers. In order to reach the quantum size regime even smaller diameters are necessary. It is possible to remove the oxide shell and further reduce the silicon core by a thermal dry oxidation step. We will present results on how the thickness of the oxide shell depends on the duration and temperature of the oxidation process as well as the core diameter. In addition, we observe the formation of silicon nanocrystals embedded in silicon dioxide nanowires after the oxidation process. A model for the Rayleigh instability-based formation of these nanocrystals will be presented and the results will be compared to morphological instabilities that can be observed during the growth of the nanowires.