Removal of hydrogen from 2H::Si(100) by sputtering and recoil implantation

In order to explore more completely the role of plasma ions in the epitaxial growth of silicon thin films by Remote Plasma Chemical Vapor Deposition (RPCVD), the energy dependent, absolute cross sections for the removal of hydrogen from the 2H::Si(100) surface by 100-200 eV Ar/sup +/ and He/sup +/ ions have been obtained. The measured integrated cross sections, on the order of 1/spl times/10/sup -17/ cm/sup 2/, demonstrate that Ar/sup +/ is more effective than He/sup +/ in the sputter removal of surface hydrogen. Recoil implantation removal of surface hydrogen could not be measured in the experiments, and was estimated by modeling. The modeling suggests that recoil implantation removal is of increasing importance at lower ion energies, and is larger for Ar/sup +/ bombardment than for He/sup +/. These results support the hypothesis that the generation of active sites through the removal of hydrogen from the passivated surface is an important step in the growth mechanism for RPCVD silicon epitaxy. They also explain the greater efficacy of Ar plasmas in RPCVD.