Growth of HgCdTe films on 7x7.5 cm2 CdZnTe substrates for science grade H4RG-15 image sensor applications (Conference Presentation)

Abstract

HgCdTe films are grown by molecular beam epitaxy (MBE) on large area CdZnTe substrates to achieve low dark current, high quantum efficiency infrared image sensors with 1.7um and 2.5um cut-off respectively. We present the structural and optical characterization of our HgCdTe films with emphasis on spatial uniformity across 7x7.5cm2 wafer size. Science grade detectors are fabricated on these films and subsequently hybridized to our H4RG-15 4K x 4K readout integrated circuit (ROIC). Test results from these image sensors show low dark current ( 99%), less than 1.0% cross talk and a well capacity larger than 70,000e-. the operation temperature is between 80-110K. These image sensors are also responsive in the visible-IR region due removal of the CdZnTe substrate after hybridization. This feature enables spectrographs to use a single image sensor for both visible and IR regions. These image sensors are developed for extremely large telescopes and used in various telescopes around the world.