Surface-diffusion model in selective metalorganic chemical vapor deposition

Abstract

Selective epitaxial growth of GaAs was carried out by atmospheric pressure-metalorganic chemical vapor deposition using W and SiO2 masks, and a deposition-free region was clearly observed along the edge of the masks. The surface concentration of the reactant species on the masks was analyzed by a surface-diffusion model and a new method to estimate the surface-diffusion length on the masks was proposed. The surface-diffusion length on SiO2 and W masks were 0.45 and 0.07 μm at 610 °C, respectively. The surface-diffusion length increased with decreasing the substrate temperature and became longer on the masks irradiated by an atom beam.