HgCdTe (MCT) LWIR arrays by MOCVD on GaAs

MOCVD growth of MCT on GaAs or GaAs/Si provides a means of obtaining large areas of high quality material at low cost for IR array processing. The authors report results from LWIR arrays on MCT grown on GaAs via a CdTe buffer. The arrays were processed by a modified planar technology. The n on p junction is formed by Hg diffusion through a mask on p-type layers. Sputtered passivation layers were used to reduce surface recombination effects. Typical photodiodes had R/sub 0/A products of 10 Omega cm/sup 2/ at 77 K ( lambda /sub co/ 11 mu m). These were obtained with high quantum efficiencies (greater than 70%) and 77 K detectivities of 1.1*10/sup 11/ cmHz/sup 1/2//W. Results from arrays of photodiodes are included.<
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