DEPOSITION TECHNIQUE FOR PRODUCING HIGH QUALITY COMPOUND SEMICONDUCTOR MATERIALS

摘要

Deposited layers are advantageously obtained by utilizing a specific hydride vapour phase epitaxy deposition procedure. In this procedure, a vertical growth cell structure with extended diffusion layer, a homogenising diaphragm, sidewall purging gases, anal independent gas and substrate heaters is used for the deposition of III-V and VI compound semiconductors. This gas flow is uniformly mixed through the extended diffusion layer and directed so that it contacts the full surface of the substrate to produce high quality and uniform films. Exemplary of such gas flow configurations are the positioning of a substrate at a distance from the gas outlets to allow the extended diffusion and a diaphragm placed in a short distance above the substrate to minimise the impact of the convection effect and to improve the uniformity. This symmetrical configuration allows easy scale up from a single wafer to multi-wafer system. This vertical configuration allows the quick switching between different reactive gas precursors so that time modulated growth and etch processes can be employed to further minimise the defects density of the deposited materials.