Lattice damage produced in GaN by swift heavy ions.

Wurtzite GaN epilayers bombarded at 300 K with 200 MeV 197 Au 16+ ions are studied by a combination of transmission electron microscopy (TEM) and Rutherford backscattering/channeling spectrometry (RBS/C). Results reveal the formation of near-continuous tracks propagating throughout the entire∼ 1.5-µ m-thick GaN film. These tracks,∼ 100Å in diameter, exhibit a large degree of structural disordering but do not appear to be amorphous. Throughout the bombarded epilayer, high-resolution TEM reveals planar defects which are parallel to the basal plane of the GaN film. The gross level of lattice disorder, as measured by RBS/C, gradually increases with increasing ion fluence up to∼ 10 13 cm-2. Based on these results, physical mechanisms of the formation of lattice disorder in GaN in such a high electronic stopping power regime are discussed. [ABSTRACT FROM AUTHOR]