InAsSb hybrid imager evaluation

Abstract

Current research on infrared hybrid focal planes is directed toward devices in which detection occurs in a p-n junction formed in an intrinsic narrow energy bandgap semiconductor, and signal processing is accomplished in a Si CCD multiplexer which is electrically interfaced to the detector array. A hybrid array such as this, where the detector format is a 32 × 32 matrix, has been fabricated. The active material is backside-illuminated InAsSb which has been planar processed and fully passivated. The cutoff wavelength is 4.0 µm at the operating temperature of 77K. The CCD is four phase with a two level polysilicon gate structure. The signal input is via direct injection with an option for dc suppression. Operation of the focal plane in a staring mode that uses dc suppression is discussed. Data derived from the video output is presented; this includes responsivity and detectivity. Off focal plane non-uniformity compensation is also discussed. Displays of thermal images utilizing processed data from the hybrid focal plane array will be shown.