Polycrystalline silicon (poly-Si) thin films were deposited by remote plasma chemical vapor deposition (RPCVD) using a gas mixture of SiF 4 -SiH 4 -H 2 . Structural and electrical properties were determined as a function of the substrate temperature T s (220-450°C). The deposition rate was found to decrease with increasing T s . The etch rate by F atoms increases with T s , which explains the observed behavior of the deposition rate. The polycrystalline volume fraction was found to be approximately 81% and the average grain size is 20-100 nm for the poly-Si films deposited between 220°C and 350°C. The optical band gap decreases (1.8 eV to 1.6 eV) with increasing T s . An exponential absorption edge in the optical absorption coefficient, i.e. the Urbach absorption edge, is observed in the poly-Si films. The Urbach energy, indicating the disorder of the material, increases (80-150 meV) with increasing T s .