6.3 Oxidation and Oxide/SiC Interface Characteristics
A unique advantage of SiC is that it is the only compound semiconductor that can be thermally oxidized to give high-quality . Therefore, thermal oxides of SiC are utilized as a gate dielectric in metal-oxide-semiconductor (MOS) devices as well as to passivate the SiC surface. However, the most striking difference from Si technology is, of course, carbon atoms, which are one of the host elements in SiC. A number of review papers on SiC MOS have been published [146–156]. In spite of continuous improvement of the SiC MOS interface, the quality, and the community's understanding of the factors which control this quality, is still at far from a satisfactory level. This subsection describes the common features, present understanding, and problems in SiC MOS technology.
6.3.1 Oxidation Rate
Thermal oxidation of SiC is expressed by the following simple equation:
Therefore, a thermal oxide of SiC is , the formation of which can be confirmed by X-ray photoelectron spectroscopy (XPS), electron energy loss spectroscopy (EELS), and Auger electron spectroscopy (AES). Taking into account the Si density in SiC, the amount consumed during ...