Silicon carbide single crystal is excellent materials for various application field such as high power, high temperature, high frequency operation of devices. Recently, in the semiconductor process, the ring shape SiC single crystal which fabricated via physical vapor transport (PVT) method is widely used to protect the electrostatic chuck, to guide the Si-wafer and to distribute the plasma uniformly. Therefore, the SiC single crystal ring is required to has low etch rate, and the electrical resistance as well. Recently, it is reported that the etch resistance had strong relation with the growth direction of SiC single crystal and showed 4H-SiC is more structural stability than 6H-SiC because of the maximum attractive interactions between the stacking layers.
In this study, we have investigated the correlation between growth direction and etch resistance in comparing etch depth by Ga+ ion beam. We confirmed the main growth direction of the SiC single crystal which growth by PVT method through electron back scattered diffraction (EBSD) and the etch rate comparison is conducted with ion beam irradiation in the focused ion beam (FIB) system.
As a result, 4H was higher than that of 15R and 6H in the indexing rate of SiC. Initially, most grains are oriented toward <0001> and all grains grow toward <0001> direction as they grow.
SiC single crystal was irradiated with different ion doses. Through this study, we compare the etch rate of the basal <0001> and the other sides to investigate the direction of the plane direction with a small etch rate and its relation to the growth direction.