Analysis of a time-dependent supply mechanism in selective area growth by MOCVD

Abstract

In this work, we study the growth evolution of InP stripes deposited between dielectric masks aligned to [0 1 1] on (1 0 0) InP substrates. Ridge formations are observed adjacent to the mask, which cannot be quantitatively described by existing selective area growth models. We present a model that includes the migration of precursors from the ridge sidewall at the edge of the mask to the (1 0 0) plane via surface diffusion. Time-dependent boundary conditions are used to describe the number of precursors available for migration. Using the model in conjunction with a vapor phase diffusion model reported earlier, simulated growth rate enhancement profiles are generated and compared with experimental data obtained from surface profilometry. For films thicker than 4000 Å, inclusion of the time-dependent supply mechanism is shown to significantly improve the simulation accuracy. The new model is also used to extract the (1 0 0) surface diffusion length from experimental data.