Low leakage current in isolated AlGaN/GaN heterostructure on Si substrate by N ion implantation performed at an elevated temperature

Electrical characterizations of AlGaN/GaN heterojunctions isolated by N implantation at elevated temperatures were investigated. Three-terminal measurements were carried out to characterize leakage paths, and crystal lattice damage due to implantation was monitored by high-resolution x-ray diffraction. Compared with room temperature implantation, the current leakage was reduced by similar to 10(3) times by the implantation at 300 ?. The low leakage was attributed to low acceptor-like energy levels due to low crystal lattice damage by the "dynamic annealing " effect at high-temperature implantation. The post-annealing process increased the current leakage by two orders of magnitude. This indicates that the implantation isolation process should be conducted after higher temperature processes (> 450 ?) in the fabrication of GaN devices. These results can provide valuable information for the fabrication, reliability, and mass production of various GaN-based photonics and electronics.