The growth of polycrystalline Si films onto Al-coated Corning 7059 glass substrates using hot-wire chemical vapor deposition (HW-CVD) was investigated. The crystalline fraction, grain structure and average grain size of the films were compared as a function of the growth rate and the Si/Al thickness ratio. Micrometre-size Si grains were achieved with a Si/Al ratio of 2 and Si thickness of 2 mum at a growth rate of 1 mum h(-1). It was found that the films had a bimodal grain size distribution, which included nanocrystalline Si, and that the growth of micrometre-size crystallites does not continue as the thickness of Si film increases. At a growth rate of 5 mum h(-1), films are similar to those grown on glass with an average grain size less than 60 urn and crystalline fraction of similar to75%. (C) 2003 Elsevier Science B.V. All rights reserved.