Silicon epitaxy on germanium using a SiH4 low-pressure chemical-vapor deposition process

Abstract

This work describes a process of Si epitaxy on a (100)Ge surface using a SiH4–H2 gas low-pressure chemical-vapor deposition (LPCVD) system. Germanium epitaxial film formed on (100)Si wafers using GeH4–H2 gas in a LPCVD reactor was used as the experimental substrates. It was found that Si grew epitaxially through a SiH4 thermal decomposition reaction on the clean Ge surface within a growth temperature range of 650 to 730 °C. By contrast, (110)-oriented polycrystalline Si grew at a higher temperature of 790 °C. It was clarified that the reason for this polycrystalline Si growth at 790 °C was that the Si epitaxy was disturbed by the Si oxide layer which forms immediately on the Ge surface through susceptor-induced SiO in the LPCVD reactor.