Low temperature silicon thermal CVD epitaxy using dichlorosilane and difluorosilane as reactant gas

Abstract

The effect of adding difluorosilane (SiH 2F 2) to dichlorosilane (SiH 2Cl 2) on low temperature silicon epitaxy was investigated using the conventional barrel type epitaxial reactor. It was shown that the crystalline quality was improved by the addition of difluorosilane at low temperature epitaxy. With about 7% difluorosilane in silicon source gas (dichlorosilane), and under reduced pressure, the epitaxial growth temperature for excellent crystal can be lowered to 800°C. It is thought that the added difluorosilane acts to remove the native oxide on the surface of silicon substrates.