Nickel-silicide-induced crystallization of hydrogenated amorphous silicon thin films has been investigated. Intrinsic and doped films were deposited on glass substrates by HF-PECVD, and Ni was do Sputtered on top. Nucleation and growth of grains were followed by optical microscopy, scanning electron microscopy (SEM), UV reflectance and X-ray diffraction. Homogeneous, large and oriented grains, with diameters over 25 mu m, were obtained in intrinsic and lightly boron-doped films. Phosphorous-doped films presented a random needle-like growing mechanism, instead of the disk shape shown by the other samples. The effect of doping elements on the crystallization process is discussed. (C) 2008 Elsevier B.V. All rights reserved.