Growth of strain relaxed Si1-yC y on Si buffer layer by gas-source MBE

We studied the growth of strain relaxed Si1-yC y films on Si(001) substrates. The critical thickness of Si1-yC y on Si was calculated using People's equation. The strain relaxed Si1-yC y films on Si substrates were grown by gas source MBE (GS-MBE) and it was found from cross sectional TEM analysis that the use of Si buffer layers was very important in order to obtain high quality Si1-yC y films. Lattice relaxation was clearly observed when the thickness of the Si1-yC y layers exceeded their critical thickness. The relaxation ratio of Si1-yC y films with a carbon concentration of 1.0% was 40% in the vertical direction when the film thickness was 1800 nm