Pattern size effect on source supply process for sub-micrometer scale selective area growth by organometallic vapor phase epitaxy

Abstract

The effect of mask pattern size on source supply process was investigated for selective area growth (SAG) by organometallic vapor phase epitaxy, and for sub-micrometer scale mask patterns in particular. Theoretical expressions of the growth rate were formulated with respect to two separate processes: surface diffusion and vapor phase diffusion. The dominant process was found to depend on the size of the mask pattern. When the mask pattern size is comparable to the surface diffusion length on the mask, the surface diffusion process is dominant. However, when the mask pattern size is much larger than the surface diffusion length, the vapor phase diffusion process becomes dominant. Experiments on SAG of InP were conducted using a sub-micrometer scale mask pattern and the experimental data growth rate agreed well with that predicted theoretically for the surface diffusion process. The theoretical predictions of this study correctly explain the size effects observed experimentally and are also consistent with other studies that use large-size mask patterns in which the vapor phase diffusion process is dominant.