ABSTRACT CTS-9319770 James Edgar Localized, confined-area epitaxy is developed to reduce the defect density of silicon-carbide (SiC) films on silicon (Si) substrates. The hypothesis is to eliminate defect propagation through the necking process, in which defects terminate on the side planes of the SiC; epitaxial silicon carbide deposited after the necking process should contain fewer defects. Both selective silicon carbide growth on silica-masked silicon and anisotropic growth on nonplanar patterned silicon are examined as methods of confining epitaxy to small areas. New source chemistries using chlorinated hydrocarbons and silanes with helium as a carrier gas are explored in attempts to selective epitaxial growth at reduced temperatures and to increase growth anisotropy on various crystal planes. The shape and orientation of the window pattern, the chlorine content of the source materials, the operating pressure, and temperature are varied to minimize the propagation of defects. Silicon carbide is an attractive semiconductor for many electronic and optoelectronic applications, including high-speed, high-power devices, devices that must operate at elevated temperatures, microelectromechanical sensors, and solar-blind ultraviolet detectors. However, such applications are hampered by the difficulty of obtaining low-defect silicon-carbide films on other semiconductors. It is this issue that is addressed in this research.
