Dislocation generation in GaN by dicing process

Abstract

In order to analyze effect of the dicing process on the GaN epitaxial layer, the GaN-wafer is cut in sizes of the 0.7 mm square and the 1.7 mm square. The crystal characteristics of the GaN-chips have been measured using X-ray measurements and Raman spectra measurements. The full-width half maximum (FWHM) values of the X-ray rocking curves of (0002), (10-13) and (10-12) of the 0.7 mm square GaN-chip become wider than that of before the dicing process. The E 2 (high) peak of Raman spectra at the edge in the 0.7mm square GaN-chip is shifted to lower wave number. In consideration of crystallography, we infer from these results that both the crystal strains and the screw dislocations have been generated during the dicing process.