New approach to the kinetics of silicon vapor phase epitaxy at reduced temperature

The rate of silicon homoepitaxy from SiH4/H2 mixtures has been studied between 750 and 850 °C using a new ultrahigh-vacuum-compatible low pressure reactor. The analysis of the experimental data is novel in including the effects of both nonepitaxial deposition within the reactor and of gas pumping speed. Epitaxy by pyrolysis of SiH4/H2 mixtures on clean Si substrates between 800 and 850 °C is first order in SiH4 pressure but zero order in H2 pressure at least to 1 mm Hg. The results do not support models of growth mechanism derived from previous studies.