4H-SiC肖特基二极管γ射线探测器的模型与分析

Model and analysis of 4H-SiC Schottky diode as γ-ray detector

在研究反偏压4H-SiC肖特基二极管作为γ射线探测器工作机理的基础上建立了数值模型,模拟了不同偏压和辐照剂量率下探测器的暗电流、工作电流和灵敏度。模拟结果表明:探测器的灵敏度随反向偏压的增加而上升;对于Au/SiC肖特基二极管,有源区掺杂数密度为2.2×1015cm-3时,0 V偏压下探测器的灵敏度为13.9×10-9C/Gy,100 V偏压下为24.5×10-9C/Gy。计算结果与实验数据符合得较好。

In this paper, a numerical model is proposed based on the investigation of the operational mechanism of reversely biased 4H-SiC Schottky diode as y-ray detector. The detector characteristics of dark current, current response and sensitivity at different bias voltages and irradiation doses are simulated. The sensitivity increases linearly with the square root of the total voltage across the Schottky diode. When the doping concentration in the epitarial layor is 2.2 × 10^15 cm^-3 , the sensitivity is 13.9× 10^-9 C/Gy at zero bias, 24.5 × 10^-9 C/Gy at.bais of 100 V. The results from simulation agree very well with the experimental data.