Enhancement of the steady state minority carrier lifetime in HgCdTe photodiode using ECR plasma hydrogenation

Abstract

This paper reports the effects of electron cyclotron resonance (ECR)H₂ plasma hydrogenation on the characteristics of HgCdTe devices for the first time. We compared the characteristics of photodiodes and n-channel enhancement type field effect transistors (FETs) in the hydrogenated regions with those in the unhydrogenated regions on the same wafer. From the measurement of the photodiodes, it was found that the steady-state minority carrier diffusion length was increased from 19 to 28 urn by the hydrogenation. The surface mobility of the n-channel FET was about 5800 cm²Vs and was not varied by hydrogénation. From these facts, the steady-state minority carrier lifetime is increased about two times by the ECR H₂ plasma hydrogenation. We believe that the ECR hydrogenation can effectively reduce the surface trap-states which results in increasing the minority carrier lifetime and improving the characteristics of HgCdTe devices.