Abstract: Multispectral infrared detectors are needed for advanced imaging systems with capabilities to discriminate actual targets against decoys. Simultaneous detection of the infrared radiation emitted by the target in more than one wavelength range has significant advantages for this purpose. In the current invention, a technology for producing a plurality of multi-color infrared sensing elements in a monolithic array format is provided. Each element has a multi-layer structure of mercury cadmium telluride (HgCdTe), a group II-VI semiconductor. The unit cell of the integrated detector consists of two co-located detectors, each sensitive to a different infrared wavelength. The prior art to produce such infrared device arrays is ‘hybrid technology’, meaning the infrared sensing elements and the read-out electronics are fabricated on two different materials-silicon and HgCdTe and joined together by indium pillars/bumps.

Abstract: An infrared sensing device including a multi-layer II-VI semiconductor material grown by molecular beam epitaxy on a readout circuit fabricated on silicon substrate having a orientation one degree tilted from the (100) direction is provided in this invention. A method to grow single crystalline mercury cadmium telluride multi-layer structure on custom-designed readout circuit (ROIC) is provided. Due to the height difference of more than 15 micron between the two planes containing the detector output gates and the ROIC signal input gates, a mesa with at least one sloped side is fabricated and the interconnecting metal electrodes running on them to connect the detector output to ROIC input. Planar photovoltaic junctions are fabricated selectively on the II-VI mesa structure formed on ROIC. At least one infrared detecting cell being formed in the mesa, with a conductor interconnect layer connecting the detection cell to the readout integrated circuit.