For fast deposition of microcrystalline silicon (mu c-Si:H) films, a microwave-induced high-density plasma source is developed. By using this plasma source, highly crystallized pc-Si:H films can be deposited from SiH(4)+He plasma without even using H(2) dilution and substrate heating. A systematic deposition study shows that the film deposition rate increases with increase in the input microwave power and the SiH(4) flow rate. The film crystallinity also improves with power but degrades with increase in the SiH(4) flux. After optimizing the plasma conditions. the deposition of a highly crystallized pc-Si film has been realized at an ultrafast deposition rate higher than 700 nm/s. (C) 2008 Elsevier B.V. All rights reserved.