Effects of Gas Velocity on Deposition Rate and Amount of Cluster Incorporation into a-Si:H Films Fabricated by SiH4 Plasma Chemical Vapor Deposition

To deposit stable a-Si:H films at a high deposition rate (DR), we have studied time evolution of DR and amount of cluster incorporation (R) into films as a parameter of gas velocity, in the downstream region of a multi-hollow discharge plasma chemical vapor deposition reactor; because a-Si:H films containing less cluster incorporation show high stability. For a low gas velocity of 0.18 m/s, clusters are trapped between the multi-hollow electrode and the substrate and the trapped clusters absorb clusters and such absorption suppresses the cluster incorporation into films. By utilizing this phenomenon, we have realized a quite low R = 1.3 at a high DR = 0.06 nm/s.