Step-Growth Anisotropy on Thin Film Epitaxial Process
Kohei KUNIZAWA, Masahiro YAMAMOTO, Shigenobu OGATA and Yoji SHIBUTANI
Abstract:Anisotropic growth process of two kinds of steps on Al(111) substrates is performed using kinetic Monte Carlo (kMC) method. Employed kMC parameters of activation energy and attempt frequency are estimated by nudged elastic band (NEB) method and transition state theory. Obtained set of results suggest that degree of the anisotropic growth clearly depends on substrate temperature and deposition rate. We find microscopic origin of the isotropic growth is difference of diffusion rates along {111} and {100}steps, and there is a particular growth condition in which strong anisotropy is observed. At high deposition rate and low temperature, new islands which are easily generated on terraces, hinder the growth anisotropy weaker. Key Words:Kinetic monte carlo, Film growth, Anisotropy, Aluminum surface, Diffusion