Hydrogenated microcrystalline silicon (mu c-Si:H) thin films were deposited at a high rate of 1.6 nm/s by very high frequency (VHF, 146 MHz) assisted RF (13.56 MHz) plasma enhanced chemical vapor deposition (PECVD) from a different silane concentration. The effects of the additional high excitation frequency plasma and silane concentration on the deposition rate and microstructure of films were investigated. The main reasons for the improved deposition rate and crystallinity of the mu c-Si:H thin films were discussed in terms of plasma parameters. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.