Reactions of atomic hydrogen in the deposition of hydrogenated amorphous silicon by glow discharge and reactive sputtering

Three reactions of atomic hydrogen with hydrogenated amorphous silicon (a-Si:H) are proposed in analogy with known gas-phase reactions. These reactions can explain the different rates of hydrogen addition and dangling bond passivation in the deposition of a-Si:H by reactive sputtering; the presence of columnar microstructure and high spin density in a-Si:H deposited by glow discharge from argon-silane mixtures at high power and low silane concentration; and the microcrystalline nature of silicon films deposited by transport in a hydrogen discharge, and from high-power silane-hydrogen mixtures.