Fe implantation induced lattice defects and their recovery in GaN

A GaN thin film grown on sapphire substrate was implanted with Fe-57 and Fe-56 ions with energies of 60 keV, 160 keV and 370 keV and fluences selected to achieve a homogeneous concentration profile of approximately 2.6 at. % in the film. Implantation induced lattice damage was tracked with conversion electron Mossbauer spectroscopy (CEMS) after annealing the sample up to 900 degrees C. The spectral component due to Fe in lattice damage shows significant decrease on annealing above 700 degrees C, accompanied by a corresponding increase in the paramagnetic doublet component attributed to Fe substituting Ga in the wurtzite GaN lattice (Fe-Ga). After annealing at 900 degrees C, Fe-Ga accounts for 75% of the spectral area, in good agreement with the substitutional Fe-Ga fraction (80%) observed in emission channeling measurements on Fe implanted into GaN at extremely dilute concentration.

Automated summary

In this study, a GaN thin film grown on sapphire substrate was implanted with Fe-57 and Fe-56 ions to induce lattice damage. The results showed a significant increase in the spectral component of Fe-Ga and a decrease in the Fe lattice damage component during high-temperature annealing.