Sandupatla Abhinay, Arulkumaran Subramaniam, Ing Ng Geok, Nitta Shugo, Kennedy John, Amano Hiroshi
School of Electrical and Electronics Engineering, Nanyang Technological University, Singapore 639798, Singapore.
Temasek Laboratories in Nanyang Technological University, Research Techno Plaza, 50 Nanyang Drive, Singapore 639798, Singapore.
Micromachines (Basel). 2020 May 20;11(5):519. doi: 10.3390/mi11050519.
Among the different semiconductors, GaN provides advantages over Si, SiC and GaAs in radiation hardness, resulting in researchers exploring the development of GaN-based radiation sensors to be used in particle physics, astronomic and nuclear science applications. Several reports have demonstrated the usefulness of GaN as an α-particle detector. Work in developing GaN-based radiation sensors are still evolving and GaN sensors have successfully detected α-particles, neutrons, ultraviolet rays, x-rays, electrons and γ-rays. This review elaborates on the design of a good radiation detector along with the state-of-the-art α-particle detectors using GaN. Successful improvement in the growth of GaN drift layers (DL) with 2 order of magnitude lower in charge carrier density (CCD) (7.6 × 10/cm) on low threading dislocation density (3.1 × 10/cm) hydride vapor phase epitaxy (HVPE) grown free-standing GaN substrate, which helped ~3 orders of magnitude lower reverse leakage current () with 3-times increase of reverse breakdown voltages. The highest reverse breakdown voltage of -2400 V was also realized from Schottky barrier diodes (SBDs) on a free-standing GaN substrate with 30 μm DL. The formation of thick depletion width (DW) with low CCD resulted in improving high-energy (5.48 MeV) α-particle detection with the charge collection efficiency (CCE) of 62% even at lower bias voltages (-20 V). The detectors also detected 5.48 MeV α-particle with CCE of 100% from SBDs with 30-μm DL at -750 V.
在不同的半导体中，氮化镓（GaN）在辐射硬度方面比硅（Si）、碳化硅（SiC）和砷化镓（GaAs）具有优势，这促使研究人员探索开发用于粒子物理、天文学和核科学应用的基于GaN的辐射传感器。一些报告已经证明了GaN作为α粒子探测器的实用性。基于GaN的辐射传感器的开发工作仍在不断发展，并且GaN传感器已经成功检测到α粒子、中子、紫外线、X射线、电子和γ射线。本综述阐述了良好辐射探测器的设计以及使用GaN的最先进的α粒子探测器。在低位错密度（3.1×10/cm）的氢化物气相外延（HVPE）生长的自支撑GaN衬底上，成功地将GaN漂移层（DL）的生长改进为电荷载流子密度（CCD）低2个数量级（7.6×10/cm），这有助于将反向漏电流降低约3个数量级，同时反向击穿电压增加3倍。在具有30μm DL的自支撑GaN衬底上的肖特基势垒二极管（SBD）也实现了-2400 V的最高反向击穿电压。低CCD形成的厚耗尽宽度（DW）导致即使在较低偏置电压（-20 V）下，电荷收集效率（CCE）为62%时也能改善高能（5.48 MeV）α粒子检测。这些探测器还在-750 V下检测到来自具有30μm DL的SBD的CCE为100%的5.48 MeVα粒子。
