The extension of a previous investigation of plasma-film interactions in a-Si:H rf sputtered in He/H2, Ar/H2, and Xe/H2, at a target-to-substrate gap d = 1", to include higher gaps and rf sputtered a-Ge:H, is described and discussed. As expected, the interactions are weakened at d≥2", and the resulting films appear to be more relaxed than at d = 1". The analysis of the IR stretch and bending mode bands in annealed films sheds new light on relaxation processes and the relation between the stretch mode structure and the optoelectronic quality of a-Si:H films. In a-Ge:H, the deposition rate increases with increasing rf power in a manner similar to that in a-Si:H, and decreases exponentially with increasing d. The dihydride and trihydride bonding configuration densities decrease and the photoconductivity increases with increasing rf power (as in a-Si:H) and increasing d. These phenomena are discussed in relation to the dependence of the plasma-film interactions on these parameters.
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