HETEROEPITAXIAL GROWTH OF SI ON GAP AND GAAS-SURFACES BY REMOTE, PLASMA-ENHANCED CHEMICAL-VAPOR-DEPOSITION

Heteroepitaxial thin films of Si have been deposited onto GaP and GaAs substrates at low temperatures, <400-degrees-C, by remote plasma-enha nced chemical vapor deposition. Cleaning and passivation of the GaP an d GaAs surfaces, by ex situ wet chemistry, and in situ exposure to ato mic-H at temperatures from 400 to 530-degrees-C, were found to be crit ical in promoting epitaxial growth. The exposure to atomic-H was effec tive in removing surface oxides and hydrocarbon contamination. After t he H-exposure, low energy electron diffraction (LEED) measurements rev ealed an ordered 1 X 1 structure for the GaP(111) surface, and a c(8 X 2)Ga structure for the GaAs(100) surface. Heteroepitaxial films of Si have been deposited at temperatures from 300 to 400-degrees-C and pre ssures between 50 and 500 mTorr, with the highest quality epitaxial gr owth proceeding on vicinal GaP(100) surfaces. In contrast, for the gro wth of Si on GaP(111) and GaAs(100) surfaces, LEED measurements indica te the onset of strain-induced disorder within the first few monolayer s of the Si overgrowth.