Chemical beam, gas-source molecular beam, and molecular beam epitaxial growth of III/V compound semiconductor materials

Abstract

A new and unique high vacuum crystal growth system has been developed. The gas source molecular beam/chemical beam epitaxial growth system features a 7000 l/s diffusion pumping system mounted directly beneath a molecular beam epitaxial growth chamber. After careful thermal cleaning of the new growth chamber, p-type GaAs of higher purity than previously reported has been grown by diffusion pumped molecular beam epitaxy. The purity of GaAs grown by this method increases directly from increased pumping. The system has also been used for growth of GaAs by gas-source molecular beam epitaxy and chemical beam epitaxy and the effects of a number of growth parameters on background carrier concentration are reported.

High quality InGaP has been grown by gas-source molecular beam epitaxy. The differential thermal expansion coefficient of InGaP on GaAs has been determined directly from variable temperature x-ray measurements. InGaP has also been grown by chemical beam epitaxy. Although the quality of the layers is inferior to those grown by gas-source molecular beam epitaxy, the work presented here is one of the first reports of InGaP grown by chemical beam epitaxy.

The results of these investigations are presented and the problems and advantages of the system are discussed.