HgCdTe infrared linear arrays for 3-5- and 8-12-μm wavelength regions

Hg 1-x Cd x Te (x approximately equal to 0.205, 0.27) 64 photodiode hybrid linear arrays for spectral regions (lambda) approximately equal to 3 - 5 and 8 - 12 micrometer have been designed. The p + -n-diodes were As-diffused n-type indium doped single crystals (n approximately equal to (2 - 5) 10 15 cm -3 ) delineated with standard wet photolithography technique. Surface leakage current at T equals 80 K seems to be the dominant current mechanism for the diodes with no passivation coating. At higher temperatures the generation-recombination mechanism was found to be the principal one. Diodes had mean detectivity values D * (10.5 micrometer, 500, 1) approximately equal to 2 10 10 and D * (6.0 micrometer, 500, 1) approximately equal to 6 10 10 cm Hz 1/2 W -1 at 80 K. The arrays were interconnected to silicon direct injection readout devices with CCD multiplexers which consist of input circuits, shift register and output circuits. The dynamical range was estimated to be of the order of 60 dB at T equals 80 K. The two-phase p-channel CCD shift register was designed with clock frequency operation $less than or equal to 5 MHz. Transfer efficiency without fat zero was 0.99985 at 1.0 MHz frequency. The control interface based on 16-channel, 10-bit A/D converter was developed for computer data recording and signal processing.