Solid phase crystallization of protocrystalline silicon films (pc-Si:H) deposited by radio frequency plasma enhanced chemical vapor deposition and annealed at 600 degrees C in a vacuum furnace has been investigated. The structural, optical and electrical properties are studied for the as-deposited protocrystalline films. The effects of variation of deposition power on the properties of protocrystalline (initial) and crystallized (after annealing) films have been investigated. The dependence of the structure of the crystallized films on the properties of as-deposited films has been studied. It has been observed that the surface morphology of the crystallized films obtained by scanning electron microscopy is highly influenced by the bonded hydrogen content of the as-deposited protocrystalline films. It is also observed that the rate of crystallization during annealing is much faster for pc-Si films than a-Si. X-ray diffraction study, Raman spectroscopy and transmission electron microscopy reveal formation of smooth, large grained crystallized silicon films by solid phase crystallization of protocrystalline films deposited at medium plasma power regime, (c) 2007 Elsevier B.V. All rights reserved.