As the crystal size increased, the uniformity of the thermal field sharply decreased, resulting in two facet regions on the 8- inch crystal surface and an increase in the non-uniformity of the 8-inch chip resistivity. This study also confirmed through Raman testing that as the resistivity increases, the peak position of the LOPC mode shifts to higher wavelengths, the peak intensity decreases and the FWHM widens. Temperature-field optimization simulation of eight-inch silicon carbide crystal using VR-PVT software, and a special shelter structure obtained the thermal field with small radial temperature gradient and good dis tribution uniformity. Based on this temperature field, a nearly flat microconvex 8-inch silicon carbide crystal was obtained. After pro cessing the crystal into an 8-inch SiC wafer, the resistivity uniformity increased significantly, and the resistivity inhomogeneity was only 1.61 %. This provides a simple and feasible way to improve the resistivity uniformity of the 8-inch SiC single crystals grown by the PVT method.
Specific research can be found at the following links:
