2.3.3.1 Epitaxial Growth

There are many techniques for forming epitaxial layers in SiC each with its own advantages and disadvantages, ranging from vapor phase epitaxy, hot-wall epitaxy, sublimitation epitaxy, liquid-phase epitaxy, molecular beam epitaxy, and chemical vapor deposition (CVD) [61]. The clear choice at this time for low-cost, reproducibility, high quality, and throughput required for mass production, however, is CVD. In the simplest terms, variations of SiC CVD are carried out by heating SiC substrates in a chamber with flowing silicon and carbon containing gases that decompose and deposit Si and C onto the wafer allowing an epilayer to grow in a well-ordered single-crystal fashion under well-controlled conditions. Conventional SiC CVD epitaxial growth processes are carried out at substrate growth temperatures between 1450 to 1700$~^{\circ}$C at pressures from 0.1 to 1 atmosphere resulting in growth rates in the order of a micrometer per hour [27]. Higher-temperature (up to 2000$~^{\circ}$C) SiC CVD growth processes are also being pioneered to obtain higher SiC epilayer growth rates on the order of hundreds of micrometers per hour [62].

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