1. Introduction

The constituents of the earth are simple in that there are only about 118 elements that make up all the materials around us. However, our world is also very complex because almost unlimited types of matters (especially crystals and molecules) can be formed by combining these elements in different structural arrangements. In this respect, silicon carbide is unique as it has over two hundred crystalline forms and some polytypes of silicon carbide have been identified from presolar grains in meteorites. Silicon carbide is a wide bandgap semiconductor with excellent electronic characteristics that bode well for application to high-temperature, high-frequency, and high-power electronic devices. Moreover, silicon carbide is a superhard ceramic having a small density as well as superior thermal and mechanical properties.