Investigation of Inhomogeneity in Single Crystal SiC Wafers Using C-Scan Acoustic Scanning Microscopy

In this work, C-Scan Acoustic Scanning Microscopy (ASM) is used to map the defects of three SiC samples. The acoustic images indicate that numerous defects with different shapes and area sexist in the wafers. Some of the defects have areas of more than 100,000 μm2. The number of defects ranges from 1 to 50 defects/wafer. Defect mapping is essential for defect repairing or avoidance. This work shows that ASM can locate the precise positions of the crystallographic defects, which enables defects repair and yield enhancement.