A high growth rate (> 10 mum/h) Chemical Vapour Deposition (CVD) process is investigated in a vertical hot-wall, or "chimney", reactor. By the use of increased temperatures (1650-1850degreesC) and concentrations of reactants, this process is shown to enable growth rates up to 50 mum/h and demonstrates a material quality comparable to established CVD techniques until growth rates of 25 mum/h. The gas flow dynamics, the growth rate and the thickness uniformity determining steps are investigated, and the role of homogenous nucleation is analysed. The growth rate is shown to be influenced by two competing processes: the supply of growth species and the etching of the hydrogen carrier gas. The exponential increase of the growth rate with temperature is related to a Si-vapour release from clusters homogeneously nucleated in the inlet of the susceptor and acting as a growth species reservoir. (C) 2002 Elsevier Science B.V. All rights reserved.