Monolithically Integrated Multi-color Large HgCdTe Focal Plane Arrays

The availability of large format, multicolor, high performance infrared focal plane arrays is of the utmost importance to future DoD missions. The semiconductor HgCdTe is the material of choice for multicolor arrays due to its bandgap tunabilitythroughout the infrared spectral range and its high quantum efficiency. Present day 2nd generation focal plane array technology, based on the hybridization of HgCdTe arrays with separate Si readout circuitry, is facing severe limitations to futuredevelopment due to thermal mismatches, vibration failures, and parasitic capacitances. We propose a low cost, 3d generation technology that will lead to the production of the necessary multicolor, large format, high performance focal plane arrays. Theapproach employs a monolithic architecture where the HgCdTe array is grown directly on the Si readout circuit, immediately eliminating the difficulties of the hybrid approach. Our successful Phase I effort had fully demonstrated the proof of concept. Inthis Phase II project, we propose the production of single and two color (short- and mid-wave infrared) monolithic array heterostructures will be grown and processed on the silicon circuitry( with intermediate CdTe buffer layers) and monolithic integrationwill be accomplished. The high performance, low cost, monolithic arrays to be produced will have many military and commercial applications. They include night vision and poor weather imaging for military operations, night driving, aircraft landing,commercial trucking, ship navigation and search and rescue; target identification; surveillance; fire rescue in smoke-filled environments; industrial applications such as process control, large area temperature monitoring and preventative maintenance;environmental monitoring for pipe leaks, hazardous material spills, automobile exhaust emissions, and the status of high power electrical systems; and non-invasive medical measurements of temperature for tumors and blood flow.