Semester

Summer

Date of Graduation

2004

Document Type

Dissertation

Degree Type

PhD

College

Statler College of Engineering and Mineral Resources

Department

Chemical and Biomedical Engineering

Committee Chair

Charter D. Stinespring.

Abstract

Large area and high quality SiC substrates are required for many applications. The goal of this research is to develop novel methods of growing epitaxial silicon carbide (SiC) on 6H-SiC and silicon (Si) substrates while extending our understanding of the growth mechanisms and the effects of key growth parameters. High temperature hydrogen-etching procedures for preparing atomically-stepped 6H-SiC substrates suitable for epitaxial growth were also developed.;This dissertation presents results of both homoepitaxial SiC growth on 6H-SiC substrates and heteroepitaxial growth on Si substrates by gas source molecular beam epitaxy. The experimental variables included gas species, molecular flux, growth time, and substrates growth temperature. In particular, the growth species considered here were methylsilane and dimethylsilane, and the substrate temperatures were 700°C and 800°C. The thin films grown in these studies were characterized by Auger electron spectroscopy, reflection high Energy electron diffraction, field emission scanning electron microscopy, and atomic force microscopy.;Homoepitaxial films grown on 6H-SiC substrates showed little to no change in surface chemical composition, surface crystal structure, and RMS roughness. Compared to the substrates, reductions in step height were detected consistent with previous observations for chemical vapor desposition of SiC. Thick heteroepitaxial films could be grown on Si using methylsilane as the gas source at 800°C, but voids caused by Si out-diffusion from the substrate were a problem still. Dimethylsilane produced thick epitaxial films at 800°C without substrate voids. In this case, however, the surface was terminated by C-C bonds.

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