SiO_2钝化层对GaN基PIN结构核探测器漏电流的影响

The Influence of SiO_2 Layer Passivation on the Leakage Current of GaN-based PIN Radiation Detectors

成功地制备了有SiO2钝化层和无SiO2钝化层的GaN基PIN结构核辐射探测器,并对二者的I-V特性进行了测试。实验结果表明,SiO2钝化层的存在显著地降低了GaN基PIN结构核辐射探测器的反向漏电流,在-40V的反向偏压情况下,漏电流约有2个数量级的降低。实验过程中观测到随着反向偏压的增大,SiO2钝化层对器件反向漏电流的抑制效应更明显。建立了一种表面沟道模型解释了SiO2钝化层对漏电流的影响。

GaN-based PIN radiation detectors with and without SiO2layer passivation have been fabricated.The current-voltage（I-V） properties of the detections we observed in our experiment show that SiO2layer passivation significantly reduces the detectors reverse leakage current.The leakage current is reduced about two orders of magnitude at reverse bias of 40 V.We also observed that inhibitory effect of SiO2layer passivation on the detectors reverse leakage current is more and more obvious with the increase of reverse bias.And a surface channel model has been studied to explain this suppression of SiO2layer passivation for the reverse leakage currents.