By zone melting using a scanned cw frequency doubled Nd:YAG laser beam multicrystalline silicon films on glass have been produced with grains of 100 mu m in size. These films are useful for solar cells and for thin film transistors (TFTs). In the paper the possibilities and limitations of cw laser crystallization of amorphous silicon thin films on glass are discussed. Particularly an industrial relevant high throughput process using a high power diode laser is presented. (C) 2005 Elsevier B.V. All rights reserved.