Thermal stability of F ion-implant isolated AlGaN/GaN heterostructures

• 来源期刊: 中国科学:物理学 力学 天文学（英文版）
• 年，卷（期）: 2018,（12）
• 页码范围: 84-88
• 页数: 5页
• 语种: 英文

摘要

The thermal stability of F ion-implanted isolated AlGaN/GaN heterostructures was investigated,with B ion-implanted isolation shown for comparison.The sheet resistance of as-implanted samples with F ions was lower than that with B ions due to enhanced hopping conduction.The leakage current for both implanted samples initially decreased and then increased with increases in post-annealing temperature,indicating a damage-induced isolation mechanism.Leakage reached a minimum value after 400℃ annealing,which was over 108 times lower than the saturated current (Isat) of the as-grown structure,suggesting a successful isolation.After relatively high-temperature annealing,the leakage for F implantation showed a small change,whereas that for B implantation showed significant increase,suggesting that F-implanted isolation exhibited excellent thermal stability.Leakage current measured at 300℃ for F ion-implantation was 103 times lower than the Isat of the as-grown structure,demonstrating that F ion isolation was applicable up to 300℃.Differences in current and activation energy (Ea) between the high-resistance GaN layer and F or B ion-implanted samples indicated that the leakage current originated from the region above the high-resistance GaN layer.Variation in Ea revealed that the optimal contributing states for conduction changed with operating temperature,annealing temperature,and ion species.