Optical and electrical properties of silicon-implanted α-Al2O3

We report on the optical and electrical properties of silicon-implanted c-plane and m-plane α-Al2O3 substrates. A 100 nm deep box profile with a silicon concentration of 3 × 1019 cm−3 was obtained by multiple-energy silicon implantation. Photoluminescence measurements showed that the concentration of oxygen-vacancy-related defects increased due to ion implantation and decreased by annealing at 1300 °C. The silicon-implanted c-plane and m-plane α-Al2O3 samples had a surface roughness of less than 1 nm after thermal annealing below 1300 °C in a nitrogen ambient. Current–voltage measurements of the silicon-implanted m-plane α-Al2O3 sample after annealing at 1300 °C showed 0.6 μA at a bias of 100 V.