CONVECTIVE-TRANSPORT AND INTERFACE KINETICS IN LIQUID-PHASE EPITAXY

This paper presents a time-dependent, two-dimensional model which acco unts for convective and diffusive transport, and surface kinetics in l iquid phase epitaxial crystal growth. The governing equations are solv ed numerically and the model is applied to investigate the roles of na tural convection and interface kinetics during growth under constant c ooling rate. During the initial phase, growth is found to proceed acco rding to the diffusion-reaction rate model of Ghez and Lew. Thereafter , a complex, transient natural convection pattern develops predominant ly in the upper region of the growth cell. Convection is found to enha nce mass transport considerably along the top substrate, and results i n the formation of wavy, irregularly shaped upper substrates with up t o twice the thickness of the lower ones. Another remarkable consequenc e of convection is a change in the process at large times from what wo uld be, in the case of pure diffusion, a bulk transport limited proces s, to one where interface kinetics becomes an important rate-limiting mechanism.