Sciuto Antonella, Calcagno Lucia, Di Franco Salvatore, Pellegrino Domenico, Selgi Lorenzo Maurizio, D'Arrigo Giuseppe
CNR-Institute for Microelectronic and Microsystems, VIII Strada No. 5, 95121 Catania, Italy.
Department of Physics and Astronomy, University of Catania, 95123 Catania, Italy.
Materials (Basel). 2021 Dec 30;15(1):264. doi: 10.3390/ma15010264.
4H-SiC based p-n junction UV photo-detectors were irradiated with 600 keV He in the fluence range of 5 × 10 ÷ 5 × 10 ion/cm in order to investigate their radiation hardness. The effects of irradiation on the electro-optical performance were monitored in dark condition and in the UV (200 ÷ 400 nm) range, as well as in the visible region confirming the typical visible blindness of unirradiated and irradiated SiC photo-sensors. A decrease of UV optical responsivity occurred after irradiation and two fluence regimes were identified. At low fluence (<10 ions/cm), a considerable reduction of optical responsivity (of about 50%) was measured despite the absence of relevant dark current changes. The presence of irradiation induced point defects and then the reduction of photo-generated charge lifetime are responsible for a reduction of the charge collection efficiency and then of the relevant optical response reduction: point defects act as recombination centers for the photo-generated charges, which recombine during the drift/diffusion toward the electrodes. At higher irradiation fluence, the optical responsivity is strongly reduced due to the formation of complex defects. The threshold between low and high fluence is about 100 kGy, confirming the radiation hardness of SiC photo-sensors.
为了研究基于4H - SiC的p - n结紫外光电探测器的辐射硬度，用能量为600 keV的氦离子以5×10¹⁵÷5×10¹⁶离子/cm²的注量范围对其进行辐照。在黑暗条件下、紫外（200÷400 nm）范围以及可见光区域监测辐照对电光性能的影响，证实了未辐照和辐照后的SiC光电探测器具有典型的可见光盲特性。辐照后紫外光响应率下降，并确定了两种注量状态。在低注量（<10¹⁵离子/cm²）下，尽管暗电流没有明显变化，但仍测量到光响应率大幅降低（约50%）。辐照诱导的点缺陷的存在以及光生电荷寿命的缩短导致电荷收集效率降低，进而导致相关光响应降低：点缺陷充当光生电荷的复合中心，光生电荷在向电极漂移/扩散过程中发生复合。在较高的辐照注量下，由于复杂缺陷的形成，光响应率大幅降低。低注量和高注量之间的阈值约为100 kGy，证实了SiC光电探测器的辐射硬度。
