The Deposition of Polycrystalline SiGe with Different Ge Precursors

Abstract

This paper reports on the development of poly-SiGe deposition in single wafer CVD systems. First silane and germane are used as precursors. The deposition temperature ranges from 500ºC to 610ºC. The film composition, texture, deposition rate, and surface morphology have been studied for a range of deposition conditions. Since the cracking temperature of GeH4 is much lower than that of SiH4, it is not straightforward to reach higher than 70% Ge. A new Ge precursor, Dimethyl (Amino) Germanium Trichloride (DMAGeCl), is developed to extend the Ge concentration range. The deposition of poly-SiGe with silane and the new Ge precursor, DMAGeCl, is studied. The results about the film composition, texture and deposition rate are reported. Poly-SiGe films with Ge content up to 80% are easily achieved.