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 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. The Czochralski method of approach for obtaining 100mm InSb substrates appears to hold promise for 150mm or greater InSb boule growth. During Phase I, 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, and cooling rates will be addressed. Particular focus will be on providing a pulling profile that carefully maintains a critical angle and melt/solid interface shape in order to eliminate slip and reduce the EPD to <20/cm2. The etch pit density of the larger diameter substrates will be examined, with feedback for further defect reduction processes. Phase II will fabricate FPAs made on the 150mm InSb substrates by Cincinnati Electronics and Raytheon for advanced MWIR detector demonstration capability. A high probability for successful commercialization is anticipated, as Galaxy Compound Semiconductors is singularly focused and committed to provide the best possible substrates to the military and commercial markets.