Sulfur incorporation and thickness variation in vapor-phase-epitaxial GaAs layers for FET’s

Publisher Website
Google Scholar
Abstract
Significant nonuniformities in thickness and carrier concentration were observed in thin GaAs layers grown by VPE on semi‐insulating substrates placed parallel to the gas flow in a flat temperature deposition zone. The existence of a boundary layer was taken into account to explain the variation of the growth rate along the flow direction. Since sulfur incorporation showed a linear increasing dependence on the growth rate, it was also influenced by the same mechanism. A modified reactor geometry was employed to improve thickness and doping uniformity up to an overall variation of ±2.5 and ±4%, respectively, over a useful area of about 4 cm2.