The structural characteristics of single-crystal wurtzite epilayers (grown on sapphire substrates), bombarded with 300keV 197Au+ ions at room and liquid-N temperatures, were studied by using a combination of Rutherford back-scattering/channeling spectrometry and cross-sectional transmission electron microscopy. The results revealed an extremely strong dynamic annealing of ion-beam generated defects. Lattice amorphization was not observed, even after very large doses of keV heavy ions at liquid-N temperatures. An increase in irradiation temperature, from liquid-N temperatures to room temperature, had a relatively small effect upon the production of stable structural damage. In contrast to the case of AlxGa1–xN, with x values of up to 0.6, neither damage saturation in the crystal bulk (below the random level) nor preferential surface disordering was revealed in AlN. The results also showed that the structural lattice disorder produced in AlN by high-doses of keV heavy-ion bombardment was stable to rapid thermal annealing at up to 1000C.

Ion-Beam-Produced Damage and its Stability in AlN Films. S.O.Kucheyev, J.S.Williams, J.Zou, C.Jagadish, M.Pophristic, S.Guo, I.T.Ferguson, M.O.Manasreh: Journal of Applied Physics, 2002, 92[7], 3554-8