Annealing behavior of impurities and defects in keV Er-implanted ZnO bulk single crystals

We have investigated the effect of implantation and annealing temperatures on crystalline quality, disorder recovery and dopant distribution in ZnO bombarded with Er ions using Rutherford backscattering/channeling spectrometry. The channeling results indicate that the damage retains a low level in as-implanted samples due to the dynamic annealing effect during implantation at 600 °C. It is also found that the implantation disorder is well recovered when the samples are annealed at 1000 °C for 30 min. The results also demonstrate that many Er ions diffuse towards the surface during the whole annealing program. In particular, Er is distributed almost randomly after annealing at 1000 °C for 30 min.