ABSTRACT

Development of Radiation Hardened Anti-Reflection Coatings for Long Wavelength HgCdTe Detector Arrays

Recent interest in developing system, sub-system and related technologies to defeat incoming hostile missile threats is of great interest to MDA for acquisition, tracking and discriminating various targets. Long wavelength infrared (LWIR) focal planes arerequired for high performance surveillance systems. Reliable LWIR focal plane arrays are needed for these applications that can perform in space environment without any degradation.There has been significant progress in HgCdTe detector array technology for developing LWIR HgCdTe focal plane arrays .This progress has been fueled by the many military and space applications for which HgCdTe photodiode technology has been the nearlyideal solutionBy far the most important application of HgCdTe photodiodes is in large two-dimensional electronically scanned hybrid arrays, referred to as focal plane arrays (FPAs). A hybrid HgCdTe FPA consists of a two-dimensional HgCdTe photovoltaic detector arraythat is interfaced electrically, thermally and mechanically with a matching two-dimensional array of input circuits in silicon CMOS Readout Integrated Circuit (ROIC) chip. Each HgCdTe detector element in the array has one electrical connection to itsmatching input circuit node in the silicon ROIC.These detectors tend to degrade in space environment due to solarization effects. Magnolia proposes to develop and provide MDA with improved Anti-reflection coatings that will enhance the life of these LWIR detectors. IR photo-detectors and FPA's areuseful in a wide variety of industrial, military, and scientific applications where detection of IR radiation plays a role. Most of these applications for detection and/or measurement require high performance IR detectors either as linear arrays or astwo-dimensional arrays. The market for non-defense based IR photo-detectors is expected to grow rapidly over the next 10 years.The characteristics that make multi-color IR photo-detectors suitable for defense applications also benefit many industrial and scientific applications.Several applications in environmental monitoring and control use IR sensors. For example, IR based systems can be used for chem-bio detection. In addition, IR detectors play a key role in IR spectroscopy in several medical and scientific applications.