US 12,266,693 B2
SiC epitaxial wafer, and method of manufacturing the same
Yoshitaka Nishihara, Chichibu (JP); and Keisuke Fukada, Chichibu (JP)
Assigned to Resonac Corporation, Tokyo (JP)
Filed by SHOWA DENKO K.K., Tokyo (JP)
Filed on Nov. 4, 2022, as Appl. No. 17/981,138.
Application 17/981,138 is a division of application No. 16/781,294, filed on Feb. 4, 2020, abandoned.
Claims priority of application No. 2019-020075 (JP), filed on Feb. 6, 2019.
Prior Publication US 2023/0055999 A1, Feb. 23, 2023
Int. Cl. H01L 21/02 (2006.01); C30B 25/02 (2006.01); C30B 25/20 (2006.01); C30B 29/36 (2006.01); H01L 29/16 (2006.01); H01L 29/36 (2006.01)
CPC H01L 29/1608 (2013.01) [C30B 25/02 (2013.01); C30B 25/20 (2013.01); C30B 29/36 (2013.01); H01L 21/02378 (2013.01); H01L 21/02529 (2013.01); H01L 29/36 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method of manufacturing a SiC epitaxial wafer in which a SiC epitaxial layer is formed on a SiC single crystal substrate, comprising:
a step of forming a SiC epitaxial layer on a SiC single crystal substrate,
a step of obtaining microscopic and photoluminescence images of the SiC epitaxial wafer using an inspection apparatus,
a step of identifying large-pit defects caused by micropipes in the SiC single crystal substrate and large-pit defects caused by substrate carbon inclusions, both of which are contained in the SiC epitaxial layer, using the microscopic and photoluminescence images,
a step of distinguishing the large-pit defects caused by micropipes in the substrate and the large-pit defects caused by substrate carbon inclusions by comparing the microscopic and photoluminescence images of the SiC epitaxial wafer with microscopic and the photoluminescence images of a SiC single crystal substrate in the same ingot as the SiC single crystal substrate,
a step of identifying a total number of the large-pit defects caused by micropipes in the SiC single crystal substrate and the large-pit defects caused by substrate carbon inclusions based on the distinguishing step,
wherein a total density of the large-pit defects caused by micropipes in the SiC single crystal substrate and the large-pit defects caused by substrate carbon inclusions is 1 defect/cm2 or less.