Quality improvement of SiC single crystal by modification of hot zone design adoption with denser graphite insulation in PVT growth

Abstract

The density of graphite insulation largely affects a temperature gradient of the horizontal direction of the hot-zone in SiC crystal growth using the physical vapor transport (PVT) method. Three types of stacking configurations of graphite insulation with different densities were implemented to graphite hot-zone. The stacking configuration adoption with denser graphite insulation at the seed region gives rise positive effect on the achievement of a convex crystal shape, no polytype inclusion, improvement of crystal quality as well as lower defect density due to maintainance of constant temperature gradient during the SiC crystal growth. These results were investigated using ultraviolet fluorescence (UVF) images, map of Full width at half maximum (FWHM) and shift of an X-ray rocking curve (Omega scan), and surface morphology analysis after molten KOH etching. Optimization of hot-zone design adopting with stacking configuration of graphite insulation led to high-quality SiC crystal through the PVT method.