光导型碲镉汞红外器件的曲面延伸电极工艺评价

摘要

HgCdTe IR photoconductive detector with curved extended-electrode has been fabricated, and the ability to prevent the electrode from breaking in the liquid nitrogen was studied.The electrode was normal and there were no evident changes of the resistance of the devices when the devices were taken from normal temperature into nitrogen temperature for 9 times.Nevertheless, topography of the extended electrodes imaged by SEM showed that there were some holes in the sidewall of the step of the extended electrode film.It is indicated that the resistance characterization is not sensitive to the microdefects, the characterization of the electrode stability needs to be performed in conjunction with micro morphology characterization, and the SEM is a efficient means to evaluate the stability of electrode.%制备了一种带有曲面延伸电极结构的碲镉汞光导型红外探测器,对曲面延伸电极的抗低温冲击能力进行了研究,在9次的液氮直接冲击下曲面延伸电极完好,器件电阻无大变化.通过扫描电子显微镜(SEM)对曲面延伸电极的台阶侧面微观形貌进行观察,发现在延伸台阶的侧面有孔洞出现.通过改进镀膜工艺,延伸台阶侧面的金属薄膜致密无孔洞.这表明宏观的电阻表征对微观缺陷不敏感,对电极可靠性的表征要结合微观形貌表征进行;同时适当的薄膜制备条件可以使大台阶侧面获得致密的金属薄膜,从而获得良好的台阶覆盖性.