The mainstream semiconductor devices have conventionally been ones that use a silicon (Si) substrate. In recent years, hexagonal semiconductor materials such as silicon carbide (SiC) and gallium nitride (GaN) are attracting attention in the field of power semiconductor devices, and are being developed.
Power semiconductor devices are semiconductor elements for uses in which a large amount of current flows at a high voltage, and are required to be low in loss. For instance, silicon carbide (SiC) and gallium nitride (GaN), which are materials whose dielectric breakdown voltage itself is higher than that of silicon (Si) by approximately one digit, have a feature that the reverse breakdown voltage is maintained even when a depletion layer is thin in a p-n junction portion or a Schottky junction portion. Using SiC or GaN therefore enables manufacturing a thin device and raising the doping concentration. A power semiconductor device low in on-resistance, high in breakdown voltage, and low in loss is consequently formed. SiC and GaN are also steadier in high temperature operation than Si. Great expectations are put on the use of SiC, GaN, and other hexagonal semiconductor materials which have these characteristics.