Berlin 2005 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 58: Poster IIb

HL 58.65: Poster

Dienstag, 8. März 2005, 16:30–19:00, Poster TU F

Gas-source C Predeposition and Ge Dot Formation on Si(001): Effects of Anneal Temperature for Hydrogen Desorption — •Takeshi Murata, Yuzuru Narita, and Maki Suemitsu — CIR, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai 980-8578 Japan

Self-assembled Ge dots on Si(001) surface attract much attention for their possible applications in electronics and optoelectronics. Knowing that submonolayer C predeposition is effective in minimizing and densifying the Ge dots and that gas-source processings are much favored in actual device fabrications, we have conducted Ge dot deposition with C predeposition using monomethylsilane (MMS) and germane as the C and Ge source, respectively. While the Ge growth temperature was fixed at 500C, the anneal temperature for hydrogen desorption after MMS adsorption was varied for 500, 700 and 900C. The dots were a mixture of mounds and domes, with the former being most densified after annealed at 500C. Infrared absorption spectroscopy in multiple-internal-reflection geometry as well as reflection-high-energy-electron-diffraction observation have shown that C atoms from MMS molecules diffuse into the subsurface below 500C and nucleate as SiC at around 900C. These results indicate importance of uniform distribution of C atoms in the subsurface in obtaining densified Ge dots on Si(001).