Method using cadmium-rich CdTe for lowering the metal vacancy concentrations of HgCdTe surfaces

摘要

A hybrid focal plane array has p-n junction photodiodes formed in a substrate (10) of HgCdTe which is passivated by a cap layer (12) of Cd-rich CdTe. The active surface of the HgCdTe substrate is passivated by annealing at a temperature sufficient to support interdiffusion between the Cd-rich CdTe capping layer (12) and the HgCdTe substrate (10). Use of the CdTe capping layer (12) with a slight excess Cd maintains the surface of the HgCdTe substrate (10) in a metal-rich phase condition.