Surface Chemistry and Kinetics of the Metalorganic Chemical Vapor Deposition of II-VI Materials

点击翻译按钮获取中文摘要

ABSTRACT CTS-9631785 This is a study of the surface chemistry underlying the deposition of cadmium zinc telluride alloy films by metallorganic chemical vapor deposition (MOCVD). It includes characterizing the atomic structure and composition of the film as it nucleates and grows on a gallium arsenide or a germanium (001) surface. Alloy growth kinetics are determined by a combination of ultrahigh vacuum (UHV) surface-science experiments, macroscopic measurements of film deposition rates, and numerical simulations of the MOCVD process. The heteroepitaxy of cadmium zinc telluride on gallium arsenide or germanium (001) is studied using a UHV scanning tunneling microscope to monitor the evolution of the interface structure as each layer of atoms is deposited. The quality of the films is evaluated using transmission electron microscopy and photoluminescence measurements. Epitaxial thin films of II-VI compounds such as cadmium zinc telluride are used in a variety of optoelectronic and magentic devices. Metallorganic chemical vapor deposition (MOCVD) is a promising method for depositing these films. However, it is a challenging process in a manufacturing environment because the film growth rate and composition depend on the intrinsic reaction kinetics, making them very sensitive to the operating conditions. This effort provides the basic knowledge needed to provide reproducible growth of thin films of II-VI compound semiconductors. ***