Structural and electrical characterizations of Si-implanted GaN with a high dose at elevated temperatures

Si implantation with a dose of 2×1015 cm−2 into GaN was performed at temperatures from 25 to 300°C, followed by annealing at 1200°C for 5 min. High resolution X-ray diffraction was used to monitor the implantation induced lattice strain after implantation and after annealing. The sheet concentrations and mobilities of electrons after activation annealing were measured by Hall measurement. Results show the effect of increasing implantation temperature on electrical activation of Si impurities in GaN is minor. Still, the lattice strain decreases with implantation temperature. The average electron concentration increases with implantation temperature from RT (6.26±0.76×1019 cm−3) to 250°C (8.06±0.98×1019 cm−3) and begins to show a trend of decrease as it increases to 300°C. The average electron mobility decreases with implantation temperature from RT (102.0±2.5 cm2 V−1·s−1) to 250°C (89.2±2.2 cm2 V−1·s−1) and begins to show a trend of increase as it increases to 300°C. The defects nature at elevated implantation temperatures and their correlation with electrical activation and scattering mechanism of carriers need further investigation.