High temperature annealing of Europium implanted AlN

AlN was implanted with 300 keV Eu ions within a wide fluence range from 4 × 1014 to 1.4 × 1017 at/cm2. The damage build-up was investigated by Rutherford Backscattering/Channelling. Sigmoidal shaped damage build-up curves indicate efficient dynamic annealing. A regime with low damage increase for fluences below 1015 at/cm2 is followed by a strong increase for intermediate fluences. For the highest fluences the damage curve rises slowly until a buried amorphous layer is formed. High temperature annealing was performed in nitrogen atmospheres at low pressure (1300 °C, 105 Pa) or at ultra-high pressure (1450 °C, 109 Pa). Implantation damage was found to be extremely stable and annealing only resulted in slight structural recovery. For high fluences out-diffusion of Eu is observed during annealing. Nevertheless, photoluminescence (PL) measurements show intense Eu-related red light emission for all samples with higher PL intensity for the high temperature high pressure annealing.