Low-Temperature Si Epitaxy by Photochemical Vapor Deposition with SiH2Cl2

Abstract
Epitaxial Si films were successfully grown by the mercury-sensitized photochemical vapor deposition (photo-CVD) method with SiH2Cl2 at a substrate temperature of as low as 200° C. The electrical and optical properties of the obtained films were characterized by Hall measurement, IR and Raman spectroscopy and transmission electron microscopy. Furthermore, the n-type doping was carried out by the addition of PH3 gas, and the electron concentration was varied from 1016 cm-3 to 1018 cm-3 by varying the PH3/SiH4 gas ratio. It was found from the experiments that there was a strong correlation between the SiH2Cl2 and H2 flow rates for obtaining the epitaxial Si films at a low temperature.