Characterization of SiC Wafers by Photoluminescence Mapping

The effectiveness of room-temperature photoluminescence (PL) mapping wasdemonstrated for nondestructive detection of structural defects, such as dislocations, micropipes andstacking faults, in SiC wafers. PL spectra of bulk wafers were dominated by deep-level emissionsdue to Si vacancies, vanadium a...
Ausführliche Beschreibung

The effectiveness of room-temperature photoluminescence (PL) mapping wasdemonstrated for nondestructive detection of structural defects, such as dislocations, micropipes andstacking faults, in SiC wafers. PL spectra of bulk wafers were dominated by deep-level emissionsdue to Si vacancies, vanadium and undefined centers like UD-1 at room temperature, while thosefrom epitaxial wafers involved near band-edge emission. We developed a whole-wafer PL intensitymapping system with a capability of zooming in on the area of interest with a spatial resolution ashigh as 1 μm, and showed that the mapping patterns agree well with the etch-pit patterns originatingfrom the structural defects both on a wafer scale and on a microscopic scale. The intensity contrastaround the defects varied depending on the emission band, suggesting differences in their interactionswith impurities and point defects Ausführliche Beschreibung