The influence of surface structure on growth of Si(001)2 × 1 from the vapor phase

Recent results of a Monte Carlo simulation of crystal growth on the (001) face of diamond-structure semiconductors are presented. The simulation suggests a relationship of the morphology of growing Si(001) crystal surfaces to defect structures, diffusion anisotropy, and the structure of clusters on specular surfaces and terrace edges on vicinal surfaces. The reconstruction is predicted to contain domain boundaries which are shown to be sites for preferential growth of new layers. The rate at which the domains form and their size oscillates during the growth of new monolayers on flat surfaces. The simulation results are based on an entirely kinetic model; very few terms resulting in driving forces due to reduction of total system energy are included. Most experimental observations can thus be accounted for without the need to introduce energy differences favoring certain configurations. Some discrepancies between the model results and observed morphologies cannot be accounted for by the kinetic model suggesting, for example, that some form of energy difference for adatoms adjacent to different sides of reconstruction dimers does occur. The model results provide a method for estimating fundamental properties such as the importance of dimer and second-nearest-neighbor interactions in determining the surface morphology and the populations of surface vacancies, clusters, and multiple-height surface steps.