Indium Antimonide Substrate Growth for Affordable Large-Format Mid-Infrared (IR) Imagers

A key component for stealth defense is the megapixel InSb based infrared focal plane arrays (IRFPAs) used for fighter aircraft support and protection. A significant aspect inhibiting widespread military and commercial application of InSb IRFPAs is the size of the substrates. During Phase I, the Czochralski method was highly successful in growing larger diameter InSb boules that resulted in 149.2mm InSb substrates using existing equipment. At a 50% greater diameter than what is presently available worldwide, the IR substrates were ultra-low doped (n~4-4.5x1014/cm3). During Phase II, modifications to an existing Czochralski Si puller to accommodate 150mm InSb seed holding and reduced vibration will be implemented. The thermal profile of the melt, the crystal pulling rates, meniscus angle, and cooling rates will be addressed. Particular focus will be on providing a suitable final polish and modifying existing equipment to accommodate the larger diameter wafers. Phase II Goals include 150mm Insb, a uniform EPD to <5/cm2, and a device-ready surface. In addition, the Phase II program will fabricate and test FPA components made on the 150mm InSb substrates by FLIR, L3Communications, Raytheon-Vision for advanced IRFPA detector capability analysis. Phase III commercialization probability for 150mm InSb is high, with established customers expressing commitment.