Variation in the nanostructural features of Nc-Si:H films with radio frequency power conditions

The effect of radio frequency (RF) power on the variation in the nanostructures, chemical features and surface morphology of nc-Si:H thin films was investigated. SiH4 and H2 gases were used as source materials for the films. The films were prepared by plasma enhanced chemical vapor deposition (PECVD) techniques and the power ranged from 100 to 300 W. The average crystal size of the films varied from -1 to -12 nm and the highest crystalline volume fraction reached up to -33% when the applied RF power was 300 W. At the RF power of 300 W, the relative fraction of Si-H bond in the films (R(MONO) = Si-H/sigma[Si-H(n)]n = 1,2,3) was increased up to -29%. The variation in the nanostructures and surface features of the films with applied RF power can be interpreted by the change in the collision impact of the precursor on top of the growing films.