Development of 10μm pitch XBn detector for low SWaP MWIR applications

Shrinking the pixel size in advanced infrared Focal Plane Array (FPA) detectors allows either a reduction in the system size for the same number of pixels, or an increase in the pixel count for the same focal plane area. Smaller pitch and increased pixel count enables new applications such as long range surveillance, advanced Search and Track, missile warning, persistent surveillance, and infrared spectroscopy. In the last two decades SCD has followed this path of reducing the pixel size in InSb detectors for Mid-Wave Infrared (MWIR) applications, developing and manufacturing FPAs from 30μm down to 10μm pitch. The Blackbird InSb detector with 1920×1536/10μm format was introduced in 2013. Modern electro-optical systems are also designed towards a more compact, low power, and lower cost solution compared with traditional systems. In order to meet these requirements, detectors are being developed to work at Higher Operating Temperatures (HOT). In the last few years SCD has introduced 15μm pitch MWIR detectors based on the novel XBn-InAsSb technology, which enables outstanding electro-optical performance at temperatures as high as 150K. Two XBn FPA formats were developed and are now in production: 640×512/15μm and 1280×1024/15μm. Following the above trends, SCD is currently developing a 10μm XBn pixel, designed to operate at 150K with performance similar to the mature 15μm pixel. In this paper we present results from XBn FPA test devices, where the XBn array is flip-chip bonded to a Readout Integrated Circuit (ROIC) with a 10μm pitch. Test measurements in a laboratory Dewar at 150K demonstrate dark currents of 250fA, quantum efficiency greater than 70%, pixel operability of higher than 99.5%, and excellent array uniformity.