Annealing behavior and lattice site location of Er implanted InGaN

Single crystalline InGaN epilayers with different In content were implanted with Er$^{+}$ fluences in the range of 1 $\times 10^{13}$ to 5 $\times 10^{15}$ cm$^{-2}$ at room temperature. The structural changes and lattice site location were studied with emission channeling and RBS/channeling. Photoluminescence measurements were also performed to study the optical properties of the implanted samples. After implantation of 1 $\times 10^{13}$ Er$^{+}$ cm$^{-2}$, the emission channeling results show the incorporation of a significant fraction of Er in substitutional Ga/In sites. For fluences of 1 $\times 10^{15}$ Er$^{+}$ cm$^{-2}$ the aligned RBS spectrum along the [0001] direction reveals the displacement of the Er ions into random sites in the entire implanted region. Proximity cap annealing at 400°C and 500°C leads to some damage recovery on the samples implanted with lowest fluence accompanied by an increase of the substitutional fraction of Er. Despite the lattice disorder, a fraction of the Er ions are incorporated into optically active sites and luminescence emission was observed at 1.54 micrometer after annealing at 400°C.