Measuring strain caused by ion implantation in GaN

The reaction of GaN to ion implantation was studied in thin films grown on the a-plane (non-polar) and on the c-plane (polar). 300 keV argon ions were implanted at room temperature to fluences ranging from 5 × 1012 atoms/cm2 to 8 × 1015 atoms/cm2. The structural analysis was performed using Rutherford Backscattering/Channeling and X-Ray Diffraction. The results allow to reinforce the suggestion that perpendicular strain caused by ion implantation is the driving force behind defect transformation processes inside the lattice. Furthermore, they confirm a lower relative damage level for a-plane GaN implanted with the highest fluence, in comparison with c-plane GaN, as reported previously for low temperature implantation.