High performance 256 x 256 hybrid HgCdTe MWIR focal plane arrays

Abstract

Hybrid HgCdTe 256 x 256 MWIR focal plane arrays have been developed to meet the sensitivity, resolution, and field-of-view requirements of advanced infrared imaging systems. The best devices have RMS response nonuniformities less than 3% of the mean. They have been characterized over the temperature range 80-160K. For tactical infrared backgrounds, the FPA is photon noise limited at operating temperatures up to 130K With standard two-point correction, spatial fixed pattern noise is reduced below the background photon noise. Detector arrays are fabricated on sapphire substrates using the PACE-1 (Producible Alternative to CdTe for Epitaxy) process. PACE material growth techniques have been improved to optimize detector yield, uniformity, and performance in the MWIR band. The readouts in the hybrid FPAs are CMOS switched-FET silicon integrated circuits processed with 1.5 arm design rules. The charge capacity of each 40 pm x 40 pm unit cell is 4 x 107 electrons. The video output is capable of data rates exceeding 10 MHz.