Electrical isolation of ZnO by ion irradiation

We demonstrate the formation of highly resistive single-crystal ZnO epilayers as a result of irradiation with MeV Li, O, and Si ions. Results show that the ion doses necessary for electrical isolation close-to-inversely depend on the number of ion-beam-generated atomic displacements. However, in all the cases studied, defect-induced electrical isolation of ZnO is unstable to rapid thermal annealing at temperatures above about 300 C . No significant improvement of thermal stability is found by varying ion mass, dose, and irradiation temperature (up to 350 C). Finally, a comparison of implant isolation in ZnO with that in GaN is presented.