EPITAXIAL-GROWTH OF SIGE ON AL2O3 USING SI2H6 GAS AND GE SOLID SOURCEMOLECULAR-BEAM EPITAXY

SiGe films were epitaxially grown on sapphire (0001), (011(2)over bar> ) and gamma-Al2O3(111)/Si(111) using Si2H6 gas and Ge solid source mol ecular beam epitaxy (Si2H6-Ge MBE) for the first time. The orientation relationship between SiGe and Al2O3 was investigated, by reflection h igh-energy electron diffraction, as a function of the growth temperatu re. Epitaxial growth of SiGe films on Al2O3 was possible at low temper atures in comparison with the epitaxial growth of Si. From X-ray photo electron spectroscopy, it is considered that the low-temperature growt h of SiGe was achieved by the suppression of surface reaction by-produ cts during the initial growth, because the continuous layer of SiGe wa s grown earlier due to short incubation times and a high growth rate. High nucleation densities and the high Ge contents of SiGe films at th e heterointerface were observed and is considered to be due to the dif ference of the initial growth between Si2H6 gas and Ge atoms.