Polysilicon growth kinetics in a low pressure chemical vapour deposition reactor

Abstract A general analysis of the factors affecting a chemical vapour deposition (CVD) process in a low pressure reactor is presented. It is shown that for the deposition of polysilicon from SiH 4 there is no transport control of the growth and that the kinetic behaviour is explained by a Langmuir adsorption model in which the growth rate is linearly proportional to the SiH 4 concentration and where the adsorption of hydrogen is much greater than that of SiH 4 . The flow characteristics in a low pressure CVD reactor are also examined and it is shown that for low fractional conversions of SiH 4 the growth rate is independent of gas velocity.