Plasma parameters in the fabrication of mu c-Si thin films using 915 MHz ECR plasma with SiH4/H-2 mixtures were investigated experimentally. Plasma parameters such as electron temperature and ion density were measured by a heated Langmuir probe. The deposition rate and the volume fraction of mu c-Si were measured by spectrophotometer and Raman spectroscopy, respectively. As a result, it was observed that the characteristics of plasma parameters in SiH4/H-2 plasma were different with those in H-2 plasma although the concentration of SiH4 was only about 0.1. In addition, it was found that relatively high deposition rate can be realized even under the condition of both low gas pressure and low gas flow rate. (c) 2005 Elsevier B.V. All rights reserved.