Role of adsorption kinetics in the low-temperature Si growth by gas-source molecular beam epitaxy:: In situ observations and detailed modeling of the growth

The growth rate and surface hydrogen coverage during Si gas-source molecular beam epitaxy using disilane have been obtained as functions of both the growth temperature and the source-gas pressure. The activation energy of the low-temperature (< 600 degreesC) growth rate was found to increase with the source-gas pressure, indicating a contribution by the adsorption process in these low-temperature growth kinetics. Several growth models have been constructed based on the results, among which the two-site/four-site-adsorption model [M. Suemitsu , Jpn. J. Appl. Phys., Part 2 36, L625 (1997)] showed the best fit to both the growth rate and the hydrogen coverage. (C) 2001 American Institute of Physics.