Study of radiation damage in InGaN and AlGaN films induced by 8.9 MeV Bi 33+ ions

Homogeneous radiation damage was induced in ∼250-nm-thick In0.18Ga0.82N and Al0.2Ga0.8N films by irradiation with 8.9MeV Bi33+ ions at room temperature. The ion fluence was in the range from 5×1011 to 5×1013cm−2. From the Rutherford backscattering/channeling (RBS/C) measurements, it is shown that Al0.2Ga0.8N had a radiation resistance at least one order of magnitude higher than In0.18Ga0.82N. When the ion fluence was increased from 1×1013 to 5×1013cm−2, enhanced surface peaks were observed in the RBS/C spectra for both the In0.18Ga0.82N and Al0.2Ga0.8N films, which may be attributed to the high charge state of the incident ions. Moreover, from the Raman spectra measurements, the evolution of the disorder-related B1 bands and TO-like peaks with the fluence was observed for the In0.18Ga0.82N and Al0.2Ga0.8N films, respectively.