AlGaN/GaN P-I-N紫外探测器的电子辐照效应

Effect of Electron Irradiation on the AlGaN/GaN P-I-N UV Detector

制备了Al0.1Ga0.9N/GaN异质结P-I-N结构可见盲正照射紫外探测器。用能量为0.8MeV的电子对器件依次进行注量为5×1014,5×1015和5×1016n/cm2的辐照。通过测量辐照前后器件的I-V曲线和光谱响应曲线,讨论了不同注量的电子辐照对Al0.1Ga0.9N/GaN异质结P-I-N器件性能的影响。实验表明,小注量的电子辐照对器件的反向暗电流影响不大,当电子注量≥5×1016n/cm2时才使器件的暗电流增大一个数量级。为了分析器件的辐照失效机理,制备SiN/GaN的MIS结构,并对其进行电子辐照,发现SiN/GaN之间的界面态随着电子辐照注量的增加而增加。这表明,器件的暗电流的增大的原因之一为钝化层与GaN材料之间因为辐照诱生的界面态。辐照前后器件的光谱响应曲线表明,电子辐照对器件的响应率没有产生明显的影响。

Al0.1Ga0.9N/GaN heterostructure front illuminated visible-blind UV photodetectors were fabricated,The diodes were irradiated with 0.8 MeV electrons at fluences of 5×10^13,5×10^14 and 5×10^15 n/cm-2 in turn.I-V characterization and response spectrum of the detectors were measured before and after irradiation to analyze the irradiation effect.After higher electron fluence of irradiation,the reverse leakage current is enlarged with one order.Then the SiN/n-GaN metal insulator semiconductor diodes were fabricated to study the effect on the electrical properties of SiN/n-GaN interface.The results showed that the electron irradiation induces new interface density between the SiN and GaN.The response spectrum after irradiation is slightly smaller than before irradiation which shows the radiation hardness of the AlGaN photodetector.