High-performance long-wave infrared HgCdTe scanning focal plane arrays for surveillance applications

This paper describes an advanced scanning long wavelength IR focal plane array fabricated in HgCdTe. Comprised of an array of front-side illuminated, planar n-on-p homojunction diodes mated to a Si CMOS readout integration circuit, the array has a measured average spectral cutoff wavelength of 10.8 micrometers at 65 K with an average quantum efficiency of 87%. The FPA's peak D* at temperatures of 65 and 78 K, in the absence of background radiation, exceeds 9.3 X 1011 and 2.6 X 1011 cm(root)Hz/W, respectively. No appreciable 1/f noise is evident even for reverse bias voltages as large as 50 mV. Both the spectral and the spatial responses of the diode are well-behaved; and the measured noise contribution due to background radiation agrees with theory.