Pulsed excimer laser processing of AlN/GaN thin films

A KrF (248 nm) excimer laser with a 38 ns pulse width was used to study pulsed laser annealing of AlN/GaN bi-layers and dopant activation of Mg-implanted GaN thin films. For the AlN/GaN bi-layers, cathodoluminescence (CL) showed an increase in the intensity of the GaN band-edge peak at 3.47 eV after pulsed laser annealing at an energy density of 2000 mJ/cm². Rutherford backscattering spectrometry of a Mg-implanted AlN (75 nm thick)/GaN (1.0 μm thick) thin-film heterostructure showed a 20% reduction of the ⁴He⁺ backscattering yield after laser annealing at an energy density of 400 mJ/cm². CL measurements revealed a 410 nm emission peak indicating the incorporation of Mg after laser processing.