Revisiting stacking fault identification based on the characteristic photoluminescence emission wavelengths of silicon carbide epitaxial wafers

Abstract

We revisited stacking fault identification based on the characteristic photoluminescence emission wavelengths of 4H–SiC epitaxial wafers, and we investigated 50 000 stacking faults in 70 4H–SiC wafers using wafer-level photoluminescence mapping. The characteristic photoluminescence spectra of each type of stacking fault were obtained and analyzed using high-angle annular dark-field (HAADF) high-resolution scanning transmission electron microscopy (HR-STEM) of the targeted stacking faults. Most stacking faults exhibited specific wavelengths that converged to wavelength bands when plotting all measured wavelengths against each stacking fault. Regardless of the manufacturer of the 4H–SiC epitaxial wafers, 4–6 apparent wavelength bands with a deviation of <0.5 nm from each band were observed. Double and quadruple Shockley-type stacking faults (6,2) and (4,4) and the multilayer Frank-type stacking fault (4,2) were detected at characteristic photoluminescence emission wavelengths similar to those reported in previous studies. However, the single Shockley-type stacking fault (3,1) and intrinsic Frank-type stacking fault (5,2) were detected at different characteristic photoluminescence emission wavelengths in previous studies. In the wavelength range 482–484 nm, most stacking faults investigated via HAADF HR-STEM were intrinsic Frank-type stacking faults (5,2) compared to the expected triple Shockley-type stacking faults (5,3), and we could not observe the (5,3) stacking fault. In addition, we could not observe the extrinsic Frank-type stacking fault (4,1) in the expected wavelength region based on the reported value. This study thus acts as a reference for the characteristic photoluminescence emission wavelengths of five types of stacking faults in SiC wafers and provides explanations regarding the stacking faults that are not observed.

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