Low-temperature chemical vapor deposition of epitaxial Si and SiGe layers at atmospheric pressure

Abstract

In an effort to determine the low-temperature limit for the growth of Si and Si1−xGex epitaxial layers in an atmospheric-pressure chemical vapor deposition (CVD) reactor, good quality material has been obtained at temperatures down to 600 °C, using SiH2Cl2 and GeH4 in H2 ambient. Si/Si1−xGex/Si heteroepitaxial structures are of good crystalline quality as well, showing abrupt interfaces. The Si-growth rate enhancement, caused by the addition of GeH4 to the gas flow at low temperatures, turns into growth-rate inhibition at higher temperatures. In this experiment oxygen and water partial pressures are several orders of magnitude higher than in ultrahigh vacuum CVD, without causing noticeable negative effects.