4H-SiC探测器的γ辐照影响研究

Study of gamma irradiation effect on the 4H-SiC detector

为研究4H-SiC探测器的抗γ辐照性能,使用40万Ci级的60Co源对4H-SiC探测器进行了数次辐照,累积辐照剂量最大为1MGy(Si),并在辐照后对4H-SiC的性能进行了测试。随着累积辐照剂量增加,4H-SiC探测器的正向电流增大,而反向电流恰好相反;根据4H-SiC探测器的正向I-V曲线可提取理想因子和肖特基势垒,理想因子从1.87增加到2.18,肖特基势垒从1.93V减小至1.69V;4H-SiC探测器对241Am源产生的α粒子进行探测时,探测器的电荷收集率从95.65%退化到93.55%,测得能谱的能量分辨率由1.81%退化到2.32%。4H-SiC探测器在受到1MGy(Si)的γ辐照后,与未受到辐照时相比,在探测能量为5.486MeV的α粒子时能量分辨率和电荷收集率仅退化了28.18%和2.2%,仍具备优良的探测性能。

To investigate 4H-SiC detector’s resistance to gamma irradiation, the detector was irradiated by 60 Co gamma-ray(about 4×10 5 Ci), and the maximum cumulative dose was 1 MGy. The detector’s I-V characteristics and its performance in detecting charged particles were tested after gamma irradiation. The forward current increased and the reverse current decreased as the cumulative dose was increased. The ideal factor and Schottky barrier height were extracted from forward I-V curves, and the result showed that ideal factor increased and Schottky barrier height decreased after irradiation. The detector was exposed to 241 Am source, and it was found that the detector’s performance degraded slightly after gamma irradiation. However, the detector behaved well in detection after it received gamma exposures at a dose of 1 MGy:its charge collection efficiency was 93.55% and its energy resolution was 2.32% in detecting alpha particles of 5.486 MeV. Therefore it has been proved that 4H-SiC detector has good resistance to gamma irradiation.