A 256*256-Element HgCdTe Hybrid Infrared Focal Plane Array for the 10.MU.m Band.

Abstract

We have developed a 256×256-element HgCdTe hybrid infrared focal plane array for 8-10μm band that is both large scale and highly sensitive. Three new techniques were used to achieve the large scale array. First, a thin silicon readout circuit on a sapphire substrate reduced thermal stress between the HgCdTe diode array on CdZnTe and the Si readout circuit. Second, we optimized cutoff wavelength for maximum sensitivity. Third, a CMOS type readout circuit with an interlace scheme enabled a large handling capacity. We also used a HgCdTe diode array with anodic sulfide (CdS) passivation to reduce dark current and nonuniformity of the photocurrent. Our infrared focal plane array has a noise equivalent temperature difference 0.06 K with F 2.5 optics.