FUNDAMENTAL-ASPECTS OF VAPOR GROWTH AND EPITAXY

Vapor phase growth processes have become standard for many applications. This paper will deal specifically with the vapor phase growth (mainly epitaxial) of III/V semiconductor materials. This process has increased in importance in direct proportion to the need for elaborately structured materials such as heterojunctions, quantum wells, and superlattices for the fabrication of advanced electronic and photonic devices. As the vapor growth techniques become more advanced, and more stringent requirements on uniformity and reproducibility are imposed by the move to the production environment, it has become evident that only the techniques giving sufficient control of growth will be useful. This demand for increased control can be met only if we thoroughly understand the fundamental aspects of the growth processes. Thus, the emphasis of this paper will be a review of our current understanding of the fundamental aspects of vapor phase growth. Emphasis is on the design and selection of precursor materials and the thermodynamics and the kinetics of growth. The latter topic includes both the reaction mechanisms and rates of the pyrolysis of the precursor molecules as well as the physical surface processes, including the attachment of atoms at steps on the surface.