Effect of ion species on implantation-produced disorder in GaN at liquid nitrogen temperature

The effect of ion species on the damage buildup behavior in wurtzite GaN under bombardment at liquid nitrogen temperature (LN2) is studied by a combination of Rutherford backscattering/channeling spectrometry and transmission electron microscopy. Results show that both the density of collision cascades and chemical effects of implanted species affect the damage buildup behavior during bombardment at LN2. In particular, an increase in the density of collision cascades (with increasing ion mass) strongly enhances the level of pre-amorphous lattice disorder in the crystal bulk at LN2, which is similar to the situation during bombardment at room temperature