ORIENTATION-DEPENDENT PHASE EQUILIBRIA IN In, _,Ga,As: A MODEL INCLUDING SURFACE ENERGIES?

A~t~ct-~en~tion-de~ndent growth phenomena have been observed for liquid-phase epitaxial In,_Fa,As and other ternary and quatemary III-V semiconductors. The data cannot be explained by existing regular solution phase equilibria models. In this study we have used the quasi-regular solution formulation to derive a model which al= considers equilibrium between the growing surface and the bulk solid under it. Orientation-dependent parameters characterizing the growing surface in the (100) and (11 I) directions have been included. The model is demonstrated for growth of In,_XGa,As at 650 and 62 1 “C. Excellent agreement is obtained with data for growth of the ternary on ( 1ll)B InP substrates, whereas some adjustment of the parameters are necessary to obtain similar agreement in case of growth on (100).oriented substrates.