光导型碲镉汞探测器的氢化研究

Hydrogenation on HgCdTe photoconductive detectors

为了提高碲镉汞红外探测器的性能,对ZnS钝化的碲镉汞光导型探测器进行了氢化处理研究,发现处理效果与氢等离子体密度和ZnS钝化层的厚度密切相关。对于ZnS层厚度固定的器件,通过改变氢等离子体密度发现低等离子体密度条件氢化处理更有利于提高器件的性能,表现在处理后器件响应信号提高且噪声下降,从光谱响应上表现为器件短波方向的响应抬高;对于同样的氢化处理条件,通过改变ZnS钝化层的厚度,发现具有较大厚度ZnS层的器件的氢化效果更好。SIMS测试发现氢化过程中氢离子可以穿过ZnS层到达ZnS与碲镉汞的界面处,分析认为氢离子对界面态起到了钝化作用,降低了界面态密度,提高了器件的性能。

In order to improve the performance of HgCdTe infrared detector,the hydrogenation of HgCdTe photoconductive （PC） detectors by H-plasma had been investigated.It was shown that the hydrogenation effect was closely correlated with the H-plasma density and the thickness of ZnS passivation layer. For detectors with same thickness of ZnS layer, the lower density of plasma could obtain higher signal and lower noise after hydrogenation. And the spectrum responsivity in the short wavelength direction was improved. For the same hydrogenation condition, the detectors with larger thickness of ZnS could obtain a better hydrogenation effect. It is found that , H~ penetrates through ZnS and reaches the interface between ZnS and HgCdTe by SIMS testing. It is analyzed that H＋ passivates the interface, reduces the density of interface states and improves the performance of detector.