Electronic properties of SiC surfaces and interfaces: some fundamental and technological aspects

The wide band gap semiconductor silicon carbide (SiC) is the first-choice material for power electronic devices operating at high voltages, high temperatures, and high switching frequencies. Due to their importance for crystal growth, processing, and device fabrication, the electronic properties of SiC surfaces and interfaces to other materials such as metals and dielectrics are of particular interest. Unreconstructed, H-terminated SiC surfaces which are passivated in a chemical as well as an electronic sense are obtained in a thermal hydrogenation process. It is demonstrated that deposition of Al2O3 on H-terminated SiC(0001) leads to an interface which is lower in defects than the thermally grown SiO2/SiC interface. Furthermore, starting from hydrogenated SiC{0001} surfaces it is possible to prepare unreconstructed (1x1) surfaces with one dangling bond per unit cell. These surfaces show indications for strong electron correlation effects.