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

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 TeHg-VHg 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.