CHEMICAL GAS-PHASE REACTIONS FOR A-SI-H AND MU-C-SI-H DEPOSITION

Gas-phase reactions are a critical parameter for the formation of hydr ogenated amorphous silicon (a-Si:H) and microcrystalline (mu c-Si:H) s ilicon films. On the example of the two important radicals SiH2 and Si H3, produced by different deposition methods, photo chemical vapour de position employing a CO2 laser, and the hydrogen abstraction method, t he role of the film precursors in the deposition mechanism of a-Si:H i s discussed. The transition from a-Si:H to mu c-Si:H material at diffe rent experimental parameters is correlated with the characteristic pre ssure p and is explained on the basis of SiH3 reactions.