6HSiC

6H-SiC is a silicon carbide polytype with a hexagonal crystal structure and a six-layer repeating stacking sequence per unit cell. It belongs to the wurtzite-like family of SiC polytypes and is one of the common forms used in semiconductor devices, alongside 4H-SiC and 3C-SiC.

The material has a wide energy bandgap of about 3.0 eV at room temperature, a high breakdown electric field, and high thermal conductivity relative to silicon. These characteristics support operation at high voltages and temperatures with a low intrinsic carrier concentration, making 6H-SiC suitable for high-temperature and high-power applications. Carrier mobilities and conduction properties depend on crystal orientation, doping, and defect content, but overall the material enables efficient high-frequency switching and power conversion.

Crystal growth and fabrication involve both bulk and epitaxial techniques. Bulk 6H-SiC crystals are produced by high-temperature sublimation methods, historically including the Lely process, from silicon carbide feedstock. Epitaxial layers are grown by chemical vapor deposition (CVD) on 6H-SiC substrates. Doping is used to tailor electronic properties, with nitrogen or phosphorus for n-type conduction and boron or aluminum for p-type conduction.

Applications include power electronics such as diodes and transistors, high-temperature sensors, and robust RF and UV photonic devices. The hexagonal 6H polytype offers a distinct stacking arrangement and electronic structure compared with other SiC polytypes, contributing to its specific device performance and suitability for harsh-environment operation.