Effects of arsenic implantation and rapid thermal annealing on ZnO nanorods for p-type doping

Ion implantation is a useful method of fabricating p-type zinc oxide (ZnO) nanorods; however, it typically causes structural defects in the substrate material. Rapid thermal annealing (RTA) is a well-known annealing process in the semiconductor industry used to restore lattice defects, and it has the advantage of a fast processing time. Herein, we report on the effects of arsenic (As) implantation and RTA on ZnO nanorods for p-type doping. As⁺ ions were implanted using a mid-current ion implanter. A long-duration RTA of over 10 min that was used to activate the implanted As⁺ ions and recover the destroyed ZnO lattice changed the morphology of the As⁺-ion-implanted regions. The structural recovery after RTA at over 750 °C for 1 min was significant. In the low-temperature photoluminescence spectra, a new acceptor-bound exciton emission (A°X) peak associated with the As acceptor was observed. When RTA was conducted at 950 °C, p-type behavior of the As-doped ZnO nanorods could be observed, and the hole concentration was determined to be 6.311 × 10¹⁶ cm⁻³. This result indicates that the implanted As⁺ ions were activated as p-type dopants for 1 min.