Rapid Characterization of SiC Crystals by Full-wafer Photoluminescence Imaging under Below-gap Excitation

We demonstrated the rapid and nondestructive observation of structural defects in SiC wafers by full-wafer photoluminescence (PL) imaging under below-gap excitation. The use of visible light emitting diode arrays as an excitation source is essential to the simplification of an optical system and the light excitation covering the whole wafer. We were able to observe the defect-related intensity patterns similar to those obtained by conventional laser-scanning PL mapping. The measurement time of the PL imaging was more than fifty times faster than that of the PL mapping.