Effects of Si source gases (SiH4 and Si2H6) on polycrystalline-Si1-xGex deposited on oxide by RTCVD

The deposition behavior of polycrystalline-Sil-xGex films formed on oxide b y rapid thermal chemical vapor deposition (RTCVD) using Si2H6, GeH4, and B2 H6 gases was investigated and compared to that of the commonly used SiH4, G eH4, and B2H6 gas mixture. At a fixed gas flow ratio of GeH4 to total sourc e gas, the efficiency of Ge incorporation into the poly-Si1-xGex film is hi gher using SiH4 when compared to Si2H6 as the Si source gas. Also, the depo sition rate for films using Si2H6 as a Si source gas was enhanced as the Ge content was increased, and is higher for SiH4 as Si source gas with the sa me Ge content in the poly-Si1-xGex film. In addition, resistivity was found to be lower for the films using Si2H6 gas with a fixed Ge content in the d eposited polySi(1-x)Ge(x) layer. (C) 1998 The Electrochemical Society. S109 9-0062(98)03-021-1. All rights reserved.