6.1 Introduction

Silicon carbide (SiC), one of the oldest known semiconductor materials, has received special attention in recent years because of its suitability for electronic and optoelectronic devices operating under high temperature, high power, high frequency, and/or strong radiation conditions, where the conventional semiconductor materials like Si, GaAs, and InP are considered to have reached their limits. SiC exists as a family of crystal with more than 200 polytypes and a bandgap range of 2.4 to 3.3 eV. As a wide bandgap material, SiC possesses many superior properties, such as a larger operating temperature range, a high critical breakdown field ( E _cr), high resistance to radiation and the ability to construct visible-range light-emitting devices [1]. It also distinguishes itself by a combination of high thermal conductivity (higher than that of copper), hardness second to diamond, high thermal stability, and chemical inertness. Some of the basic properties of SiC in comparison with many other semiconductor materials are presented in Table 6.1a, and the crystallographic unit cell parameters of the most common polytypes are listed in Table 6.1b. Owing to its outstanding properties, silicon carbide is expected to bring significant breakthroughs in the areas of high temperature applications, power devices, microwave devices, and LEDs. Some of the SiC-based devices and elements that have been developed thus far are listed in Table 6.2. Several review articles...