Analytical evaluation of growth process in a sub-micron scale selective-area growth by OMVPE

We investigated the effect of the mask pattern size on the source supply process of selective-area growth (SAG) by organometallic vapor phase epitaxy, especially focusing growth with a sub-micrometer mask pattern. We considered two theoretical models; a vapor phase diffusion model and a surface diffusion model, and solved the analytical expressions of the growth rate due to the models, individually. Comparison of the theoretical models shows that the predominant process changes from the surface diffusion model to the other with increasing the mask pattern size. The SAG experiments with sub-micrometer mask pattern were performed. The predominant process was found to be the surface diffusion model. In contrast, the other studies considering mask pattern over several- or several ten-micrometers often conclude the vapor phase diffusion process is dominant. The comprehensive conclusion agrees with the prediction of the size dependence indicated by the present theoretical consideration.