A high electron density (> 10(11) cm(-3)) and low electron temperature (1-2 eV) plasma is produced by using a microwave plasma source utilizing a spoke antenna, and is applied for the high-rate synthesis of high quality microcrystalline silicon ([tc-Si) films, A very fast deposition rate of similar to 65 angstrom/s is achieved at a substrate temperature of 150 degrees C with a high Raman crystallinity and a low defect density of (1-2) x 10(16) cm(-3). Optical emission spectroscopy measurements reveal that emission intensity of SiH and intensity ratio of H-alpha/SiH are good monitors for film deposition rate and film crystallinity, respectively. A high flux of film deposition precursor and atomic hydrogen under a moderate substrate temperature condition is effective for the fast deposition of highly crystallized Itc-Si films without creating additional defects as well as for the improvement of film homogeneity. (C) 2007 Elsevier B.V. All rights reserved.