Models for diffusion and island growth in metal monolayers

Abstract

We present a model which describes diffusion and island growth on FCC(001) metal substrates during molecular beam epitaxy. This model incorporates the essential characteristics of adatom hopping. To test it we performed Monte Carlo simulations for the growth of Cu on Cu(001) using semi-empirical potentials. We find that due to high edge mobility, islands are compact in the entire temperature range accessed by recent scanning tunneling microscopy experiments. The model predicts substantial dimer and trimer mobility and fast mobility of vacancies. Typeset using REVTEX 1 Recent experiments on thin film growth using molecular beam epitaxy have provided detailed information about growth kinetics and morphology. In particular the submonolayer regime has been studied extensively using both scanning tunneling microscopy (STM) and diffraction methods [1–8]. It was observed that for a variety of systems and a broad temperature range island nucleation is the dominant mechanism for crystal growth. A variety of