The Latest Developments of HgCdTe e-APDs at SITP

摘要

HgCdTe has been shown to be the first semiconductor exhibiting single-carrier multiplication in avalanche photodiodes (APDs) up to gain values larger than 1000 and with close to zero excess noise. These results have opened a new windows for low-flux and versatile imaging. In this paper, we report the latest results on a 50μm pitch 128×128 array HgCdTe APDs with x_(cd)=0.307 manufactured at SITP. Through optimizing the implantation parameters and annihilation parameters, the designed PIN junction structure could be obtained, and then the performance of APD device was improved. The APDs display a gain of 728 around 10V reverse bias, and the standard deviation of the gain was 18.3% of the mean gain of 113 at 7.8V. The GNDC is less than 100nA/cm~2 at the bias＜9V,but the dark current starts increasing significantly faster than the gain at high bias, and then the device becomes dark current noise limited. The excess noise factor F is less than 1.8 up to gain of 700, and the F factor of 94.75% pixels is less than 1.4 at gain of 126. The Noise Equivalent Photon (NEPh) is 16 photons at gain of 500, and a demonstration imaging was shown.