A STOCHASTIC-MODEL FOR CRYSTAL-AMORPHOUS TRANSITION IN LOW-TEMPERATURE MOLECULAR-BEAM EPITAXIAL SI(111)

Molecular beam epitaxial Si (111) grown below a certain temperature re sult in amorphous structure due to the limited surface mobility of ato ms in finding correct epitaxial sites. In spite of many experimental a nd theoretical studies, the mechanism of crystal-amorphous transition and its dynamics related to the growth conditions are not well underst ood. In this article, we present a theoretical model based on the form ation of stacking fault like defects as a precursor to the amorphous t ransition of the layer. The model is simulated based on a stochastic m odel approach and the results are compared to that of experiments for temperatures in the range of 500-900 K and growth rate in the range of 0.1-3.0 Angstrom/s. The agreement between our results and experimenta l observations is excellent. (C) 1996 American Institute of Physics.