Roughness, Impurities and Strain in Low-Temperature Epitaxial Silicon Films Grown by Tantalum Filament Hot-Wire Chemical Vapor Deposition

摘要

We grow epitaxial silicon films onto (100) silicon wafers from pure silane by hotwire chemical vapor deposition (HWCVD). The films grow epitaxially for a thickness h{sub}(epi) before a-Si:H cones nucleate and expand. We study the dependence of h{sub}(epi) on growth rate and the differences between Ta and W filaments. The surface morphology of thin but completely epitaxial films are studied in order to correlate the surface roughness during growth with the eventual epitaxial breakdown thickness. Surface roughness, strain and H at the wafer/film interface are not likely to cause the observed breakdown.