Key Laboratory of Infrared Imaging Materials and Detectors,Shanghai Institute of Technical Physics,Chinese Academy of Sciences
In this paper, the crystal quality of materials in key avalanche region of Mercury Cadmium telluride (HgCdTe) avalanche photodiode detector(APD) with medium wave PIN structure is studied. By simulating the entire process of the PIN APD device on the experimental material, and using differential Hall and differential minority lifetime test to characterize the material, the real crystal quality of the key avalanche area was evaluated. It is found that the crystal quality of the avalanche region under the optimized process is good, and its SRH lifetime can reach 20.7μs, which can reach the SRH lifetime of the primary material. This meets the development requirements of high quality medium-wave mercury cadmium telluride avalanche devices. At the same time, based on the obtained SRH lifetime in the avalanche region, we conducted corresponding two-dimensional numerical simulations on HgCdTe APD structural devices to obtain the theoretically optimal dark current density of 8.7×10-10A/cm2.