1.3 SiC Physical and Electrical Properties

SiC is a wide band-gap indirect semiconductor with high breakdown voltage and high saturation electron drift velocity. It is chemically inert and of high hardness. While all SiC modifications have quite the same mechanical and thermal properties, their electrical and optical properties differ greatly from polytype to polytype [10].

Electronic devices formed in SiC can operate at extremely high temperatures without suffering from intrinsic conduction effects ($10-35$ orders of magnitude lower than Si) because of the wide energy bandgap. SiC can withstand a voltage gradient (or electric field) 5 to 20 times greater than Si or GaAs without undergoing avalanche breakdown [11]. This high breakdown electric field enables the fabrication of high-voltage and high-power devices. Additionally, it allows the devices to be placed very close together, providing high device packing density for integrated circuits. SiC is an excellent thermal conductor. In fact, at room temperature, SiC has a higher thermal conductivity than any metal ($3-13$ times higher than Si) [12]. This property enables SiC devices to operate at extremely high power levels and still dissipate the large amounts of excess heat generated. SiC devices can operate at high frequencies (RF and microwave) because of the larger saturated electron drift velocity which is $2-2.5$ times that of Si [13].

T. Ayalew: SiC Semiconductor Devices Technology, Modeling, and Simulation