Low-Temperature Silicon Homoepitaxy by Hot-Wire Chemical Vapor Deposition with a Ta Filament

Growth of 400 nm epitaxial silicon films on (1 0 0) silicon wafers at temperatures as low as 280 °C is demonstrated by use of a tantalum filament in hot-wire chemical vapor deposition. Systematic studies on the effects of substrate temperature and filament current show that the thickest epitaxial layers (450 nm) are grown at temperatures of ∼380 °C and that the epitaxial thickness before breakdown (h_epi) decreases when the filament current (and growth rate) is increased. Higher substrate temperatures reduce the strain in the epitaxial layer. There are significant differences in film quality when films are grown with tantalum versus tungsten filaments, suggesting that growth chemistry is sensitive to the filament material.