Defect Mapping of Wafers for Increasing Yield and Operability of Infrared Focal Plane Arrays

The yield and operability of high performance infrared detectors, particularly those based on HgCdTe, are severely compromised by materials defects. Recently, ARI has demonstrated during its UV hydrogenation process that deuterium effectively ‘decorates’ defects in materials such as ZnCdTe and HgCdTe. In essence, the distribution of deuterium in the sample directly ‘maps’ defects in the material. This finding provides a revolutionary tool for materials assessment during HgCdTe FPA processing and production. In particular, when the ‘deuterium decoration’ process is used in conjunction with Nuclear Resonance analysis it will allow for defect ‘maps’ of ZnCdTe substrates, epilayer/buffer ZnCdTe and HgCdTe films to be obtained non-destructively. The impact that this technology, when fully developed, on processing, yield rates, and operability of HgCdTe FPA’s cannot be overstated. In this SBIR Phase I project, ARI will demonstrate a prototype system for wafer mapping for use by the FPA production houses. To this end, ARI has teamed with BAE, Raytheon Vision Systems, Teledyne Imaging Sensors, DRS and Lockheed Martin in order to ensure as rapid a transfer as possible of this manufacturing technology to MDA platforms.