Piezoelectric Effect on Plasma Chemical Vapor Deposition of Hydrogenated Amorphous Silicon Films

As a potential method for controlling the surface reaction of plasma CVD, mechanical vibration generated by a piezoelectric device was applied on the substrate during glow discharge decomposition of SiH 4 . The application of 2MHz vibration dramatically improved the photoconductivity of a-Si:H films prepared at a substrate temperature of 120°C. IR and CPM spectra for the films revealed that the piezoelectric vibration remarkably modulated the amorphous network structure and reduced the defect density to 4.3x10 14 cm −3 which is the best among the values ever reported.