Carbon doping effect on strain relaxation during Si1−x−yGexCy epitaxial growth on Si(1 0 0) at 500 °C

Abstract

On strain relaxation during Si1−x−yGexCy epitaxial growth on Si(1 0 0) using an ultraclean hot-wall low-pressure chemical vapour deposition system at 500 °C, the carbon doping effect has been investigated. The depth profile of the strain in Si1−x−yGexCy films is measured by x-ray diffraction and Raman scattering spectroscopy combined with a wet etching technique. It is confirmed that the strain relaxation of Si1−xGex films (x = 0.45) occurs uniformly at every depth from the surface to the heterointerface. On the other hand, strain relaxation occurs partially in the surface part of Si1−x−yGexCy films (x = 0.45, y = 0.016), although the bottom part near the heterointerface is still strained.