ATOMISTIC ASPECTS OF DIFFUSION AND GROWTH ON THE SI AND GE (111) SURFACES

The stability of interfaces and the mechanisms of thin film growth on semiconductors are issues of central importance in electronic devices. These can be understood through detailed study of the relevant micros copic processes. Experimental studies are able to provide detailed, at omic-scale information for model systems. Theoretical analysis of expe rimental results in essential in explaining certain surprising observa tions and in providing guidance for optimizing conditions and methods of growth. We review recent theoretical work on the diffusion of adato ms, the structure of adsorbate monolayers, and their implications for growth on the Si and Ge(111) surfaces. The theoretical analysis consis ts of first-principles calculations of the total-energy and entropy fa ctors for stable, metastable and saddle-point configuration. These cal culations are supplemented by Monte Carlo simulations of simple models that afford direct contact with experimental observations.