Phosphorus doping of epitaxial Si and Si1−xGex at very low pressure

Abstract

We report on the in situ P doping of Si1−xGex(SiH4/GeH4) and Si(SiH4) epitaxial films with 1–100 ppm PH3 at 620 °C in a very low pressure chemical vapor deposition reactor. The epitaxial growth rates were found to decrease with P doping. The growth rate reduction is a function of Ge composition and is less pronounced as the Ge content increases. In addition, P incorporation into the growing film is affected by Ge, which improves the concentration range and profile definition of P. A simple model that attempts to explain the results is discussed.