Disordering and dopant behaviour inAu+-ion-irradiated AlN

Abstract

Single-crystal AlN films on SiC were irradiated at 145 K with 1.0 MeVAu+ ions in a wide range of ion fluences. The accumulation of disorder on both the Al and Nsublattices in AlN has been investigated in situ using conventional Rutherfordbackscattering spectrometry (RBS) and non-RBS along the -axial channelling direction. The results suggest that a disorder saturation stage isattained following an initial disorder increase at doses less than 10 displacements per atom(dpa). A continuously amorphized layer was not formed in AlN for doses up to 208 dpa.Similar disordering behaviour is observed for the Al and N sublattices. The lattice disorderproduced at 145 K is thermally stable at room temperature; further irradiation does notinduce disorder recovery. The microstructures in the irradiated AlN exhibit bothamorphous and crystalline domains at the stage of disorder saturation. The implanted Audoes not show significant redistribution during the ion irradiation or room-temperatureannealing.