Amplified Detection of Threading Dislocations in n-Type 4H-SiC Epilayers Enabled by Time-Resolved Photoluminescence Mapping

Abstract

Threading dislocations (TDs) in epitaxial layers of silicon carbide (SiC) exert a negative impact on the device performance, thereby hampering the commercialization of SiC power devices. Therefore, inspection of TD defects is a crucial step in the fabrication of SiC wafers. In this work, we reported a time-resolved photoluminescence (PL) mapping technique for detecting TDs by extracting PL images at different delay times after pulse excitation along the lifetime decay curve. The results indicate a 2-fold enlargement of the TD PL quenching spot at a later delay time compared to the full delay time, enhancing the precision of TD defect imaging in 4H-SiC epitaxial layers. We postulate that our time-resolved PL mapping technique holds promise for the industrial evaluation of TD defects in SiC epitaxial layers.