Investigation of 4H and 6H-silicon carbide thin films and Schottky diodes using depth-dependent cathodoluminescence spectroscopy

Replacing Si with wide band gap (WBG) semiconductors in power electronics is expected to have a major technological impact in the energy and transport industries. SiC-based devices have already been introduced, but their performance and development has been challenged by the material degradation and problems in further producing reliable contacts and high-quality interfaces.; This dissertation investigates the native defects on SiC surfaces and interfaces using nanoscale sensitive techniques. The effect of such defects on the performance of the devices is also investigated. The effect of the processing steps on the defect formation and structural changes is studied. Critical annealing conditions and doping levels are established for the spontaneous formation of stacking faults and associated deep level defects. Localized states at the metal-semiconductor interfaces are studied for both reactive and non-reactive metals. Analogous nanoscale studies of SiC defects and their correlation with Schottky diode electrical properties are planned on a diode-per-diode basis.; This research is expected to produce greater understanding of localized interface state formation and methods to control them. Such control is required for the SiC devices to achieve their expected performance.