Temperature dependence of 1/f noise in Hg1-xCdx Te MIS infrared detectors

We measured 1/f noise on Hg_0.71Cd_0.29Te Metal-Insulator-Semiconductor (MIS) infrared detectors operated over the temperature range of 40 K to 90 K under 300 K Infrared (IR) radiation. The purpose of the study was to identify the sources of 1/f noise, especially in relation to the dark current. The devices were operated in the correlated double sampling mode where the voltage across the MIS capacitor was sampled at empty potential well and right after the accumulation of minority carriers in the well due to IR radiation generation. The noise power spectral density for the charge integrated in the MIS well was investigated in relation to the dominant component of dark current. At lower temperatures T⩽65 K, the charge noise power spectral density was found to depend quadratically on the dark current. At higher temperatures, this quadratic dependence did not exist. We attribute the dark current to a mixture of tunneling and depletion-region-originated minority carrier generation which seems to be responsible for 1/f fluctuations in these structures for temperatures below 65 K