Effect of Hydrogen Plasma Treatments at very High Frequency on p-Type Amorphous and Microcrystalline Silicon Films
AbstractVery high frequency (100 MHz) hydrogen plasma treatments on a-Si:H deposited by plasma enhanced chemical vapour deposition were studied. Ex-situ optical measurements have shown that etching and chemical transport occur as competing phenomena. The one that prevails is determined by the plasma conditions. In particular, very efficient chemical etching is observed for high H2 flow rates, while, for low H2 flow rates, the equilibrium is shifted toward deposition, and a structural modification of the sample is observed. The experimental conditions were stressed in the direction of utilizing chemical transport from the cathode to deposit very thin (7 nm) microcrystalline films with a pure H2 plasma.
Connection between hydrogen plasma treatment and etching of amorphous phase in the layer-by-layer technique with very high frequency plasma excitation