长波碲镉汞p型掺杂机理和器件低频噪声研究进展

Research progress on p-type doping mechanism and low frequency noise of long wave HgCdTe devices

针对长波碲镉汞红外焦平面器件发展的需求,本文分别从材料的p型掺杂机理和器件的低频噪声两个方面概述了相关的研究进展.(1)理论上修正了经典的As掺杂p型激活模型,并提出了新的激活模型,即以复合缺陷(Te_(Hg)-V_(Hg))主导下的As迁移,最终形成AsTe2复合体而表现为p型.(2)理论上解释了Au原子在碲镉汞材料中呈现快扩散特性,是由间隙扩散机制所导致的,提出了通过Au杂质与Hg空位的相互作用,以Hg空位作为介质来调控Au杂质浓度分布的方法,可以实现可控的p型掺杂,并被实验所验证.(3)搭建了高灵敏低频噪声的测试系统,结合器件性能仿真,构建了低频噪声的分析评价方法,并研究了长波碲镉汞器件低频噪声与器件暗电流之间的关联性.

In order to meet the needs of the development of long wave HgCdTe infrared focal plane devices,this paper summarizes the related research progress from two aspects:the p-type doping mechanism of materials and the low-frequency noise of devices.It includes:(1)the classical p-type activation model of as doping is modified theoretically,and a new activation model is proposed,that is,as migration dominated by composite defect Te_(Hg)-V_(Hg) leads to the formation of AsTe2 complex,which shows p-type.(2)It is theoretically explained that the fast diffusion characteristics of Au doped HgCdTe are caused by the interstitial diffusion mechanism;a method is proposed to control the spatial distribution of Au impurities through the interaction between Au impurities and Hg vacancies,which can realize controllable p-type doping and is verified by experiments.(3)A high sensitivity and low frequency noise test system is built.Combined with the numerical calculation model,the evaluation method of low-frequency noise is established.At the same time,the origin of low-frequency noise of long wave HgCdTe device is analyzed.