Effect of substrate material on the rate of growth and the optical parameters of a-C : H layers

a-C : H layers were grown by dc magnetron reactive sputtering of a graphite target in Ar + H-2 plasma. Ellipsometric measurements were carried out and analyzed at a wavelength of 6328 Angstrom for three sets of a-C : H layers with different thicknesses (different sputtering times) on silicon, fused quartz, and glass-ceramic substrates. It was shown that the substrate mater ial had a substantial effect upon a-C : H growth: a-C : H layers on Si subs trates were uniform up to similar to 7000 Angstrom thickness; for thin laye rs (< 1000 Angstrom) the growth rate was greater on quartz than on Si; the refractive index values of a-C : H were slightly different on quartz and Si substrates (1.60-1.65 and 1.65-1.72, respectively); a-C : H layers on glas s-ceramic substrates were not uniform and had variable refractive index. (C ) 1999 American Institute of Physics. [S1063-7826(99)02506-5].