Swift heavy ions effects in III-V nitrides

Four III-V nitrides, BN, AlN, GaN and InN have been irradiated under normal incidence at 300 K at GANIL (Caen, France) accelerator with 132 MeV 209Pb32+ swift heavy ions. Specimens were ion thinned for TEM observations before irradiation. Boron and aluminium nitrides were undamaged by the irradiation unlike the two others. In gallium and indium nitrides, ion impacts are found, forming circular areas. Their diameters are 3 and 8 nm, respectively. In fact, two regions may be distinguished around the ion impact: the inner part attributed to the section of the track formed along the ion path and corresponding to re-crystallized material and the external part to a strained material. For InN, structural defects, dislocations or interstitial loops are localised at the interface between the two regions and in the inner part.