The variation of the C/Si ratio between 0.6 and 1, keeping a Si/H2 ratio of 0.25% and a (Cl or Br)/Si ratio of 4, also shows the classical dependence of growth rate on C/Si where the growth rate decreases with more silicon rich conditions and evens out with more carbon-rich conditions, 29  for both Br- and Cl-based chemistry, Figure 4.