Automated Mapping of Micropipes in SiC Wafers Using Polarized-Light Microscope

Abstract

We have developed a process that is able to detect, count, and map micropipes on SiC substrates. This process uses a polarized light microscope to scan the wafer. The pictures taken are analyzed with a program that produces a micropipe map as well as numerical defect distribution data in a text file. The results of the process were validated with x-ray topography measurement. The repeatability of this process is also studied and reported.

Observation of in-plane shear stress fields in off-axis SiC wafers by birefringence imaging

“…Therefore, it is important to characterize dislocations in SiC wafers. Among various kinds of characterization methods, including X-ray topography, photoluminescence imaging and molten potassium hydroxide (KOH) etching (Dudley et al, 2003;Tajima et al, 2006;Katsuno et al, 1999), birefringence imaging using polarized light is a promising method for nondestructive characterization of SiC wafers (Ma et al, 2002;Ouisse et al, 2010;McGuire et al, 2018;Kawata et al, 2021). Birefringence image contrast of dislocations in various kinds of crystals has been investigated since the first observation of the stress field of dislocations in Si by Bond and Andrus (Bond & Andrus, 1956;Bullough, 1958;Maiwa et al, 1989;Ming & Ge, 1990;Hoa et al, 2014;Tanaka et al, 2019).…”