Investigation of the 6-Folded Pattern in the Facetted Region of 4° Off-Axis 4H-SiC

Abstract

We demonstrate 4o off-axis 4H-SiC bulk crystal growth using physical vapor transport method (PVT). A radial 6-folded pattern is discovered in the facetted region of the growth surface by differential interference contrast microscopy. SICA88 Wafer Inspection/Review System was used to further inspect such 6-folded pattern with photoluminescence channel for wafers cut from that 4H-SiC crystal. It was found that the 6-folded pattern exists in all the wafers from the bottom to the top of that crystal. Several radial 6-folded patterns are found in the bottom wafer near the seed, but there is only one in the other two wafers. Defects distribution of these wafers after etched were also researched to find out the relationship between the radial 6-folded pattern and the defects. Based on the results, the formation and evolution mechanism of the radial 6-folded pattern on 4o off-axis 4H-SiC crystal is discussed.