The mechanism and kinetics of the deposition of cadmium telluride from the decomposition of dimethylcadmium and diethyltellurium are determined. Preliminary results indicate that deposition occurs by a catalytic reaction consisting of the adsorption of the organometallic molecules on the alkyl groups. In this study, the elementary kinetics of adsorption and decomposition of dimethylcadmium and diethyl tellurium on (2x8) gallium arsenide (100) are determined in ultrahigh vacuum. Internal-reflection infrared spectroscopy and X-ray photoelectron spectroscopy identify the adsorbed species and measure their surface coverages. Temperature-programmed desorption is used to characterize the decomposition kinetics. A kinetic parameters become available, they are incorporated into mathematical models suitable for the design, optimization, and control of organometallic vapor-phase epitaxy (OMVPE) reactors. This project provides the fundamental data needed for process and reactor models of OMVPE, and makes a start on developing these models. OMPVE is a very promising technology for producing layered structures of compound semiconductors, which form the active region of such electronic and photonic devices as high-speed field-effect transistors, light-emitting diodes, solid-state lasers, infrared detectors, and solar cells.
