Monte Carlo simulation of the growth of semiconductor materials

We have developed a new Monte Carlo model for the simulation of growth of semi-conductor materials. Apart from the explicit incorporation of surface dimerization, the tetrahedral lattice structure, and atom-atom interactions out to second-nearest-neighbors, we extended MC model by allowing the formation of bulk vacancies and overhangs into the growing crystal.; We have obtained the results of Monte Carlo simulation study of epitaxial growth dynamics of Si(001) over a wide range of deposition rates, {dollar}Rsb{lcub}d{rcub}{dollar}, varying from 0.001 to 100 monolayers per second, and substrate temperatures, T, from 500 to 1000 K. We have studied the role of each of two driving forces controlling the growth of semiconductors--substrate temperature and deposition rate. We have demonstrated that increasing the deposition rate from 0.001 to 100 monolayer/second moves the temperature range for the change of growth mode from rough three-dimensional growth to smooth two-dimensional growth toward higher temperatures: from 650 K ({dollar}Rsb{lcub}d{rcub}{dollar} = 0.001 ML/s) to 950 K ({dollar}Rsb{lcub}d{rcub}{dollar} 100 ML/s). We have also investigated the effect of the formation of vacant sites and overhangs on the quality of growing semiconductor material. We have found that this effect is pronounced only at low temperatures, where there are no active hopping processes of atoms, while at high temperatures this effect is washed out by intensive hopping of lattice atoms. The results of the simulation of the relaxation of Si(001) surface toward equilibrium after the growth interruption have been discussed as well. We have demonstrated that there are two different mechanisms of recovery. The recovery of surface, which at low temperatures (500-600 K) is the result of hops of surface atoms located in the vicinity of vacant sites, at higher temperatures is caused by the activity of all surface atoms.; We have also simulated the growth of silicon on (111) and (411) crystallographic planes. Comparison of the results of the growth on (001) and (111) growth show that the transition from rough to smooth growth mode for (111) surface occurs at lower temperatures than in the growth on (001) surface indicating higher diffusion coefficient of adatoms on (111) surface in comparison with (001). The results of the simulation of the growth on (411) surface do not show substantial difference from (001) growth. They combine the features of the growth on (001) and (111) planes.; We have studied the formation of low-dimensional structures on the top of ridges formed on (001) and (411) planes. We have found that (111) side walls are flat in both cases due to the substrate temperature high enough to ensure high mobility of adatoms on (111) surface. The (001) and (411) surfaces on the top of the ridges are of approximately the same quality, and the only difference was obtained in their shape being symmetric in (001), and not symmetric in (411) case. Our simulations have also shown the possibility of the growth of SiGe/Si quantum wires by the deposition through shadowing mask.