GOALI: Systems Integration of Uncooled YBaCuO IR Detectors

9800062巴特勒这项建议涉及在室温下工作的高探测率热释电红外成像仪的研究和开发。国家科学基金和陆军研究室的前期工作表明，半导体薄膜YBaCuO在室温下具有很高的热释电系数，是其他薄膜材料的200倍。这使得高探测率热释电热探测器能够在集成在CMOS读出电路上的微机械热隔离结构上制造，因为用于这些成像器件的YBaCuO非晶态半导体相是在常温下沉积的，不需要高温后退火。南方卫理公会大学(SMU)的研究人员已经证明，表面微机械加工的Nb/YBaCuO/Nb电容器结构在没有外加电场和事先没有极化的情况下，能够在65nC/K cm2范围内表现出热释电系数。极化后，热释电系数增加到18(C/cm2-K)。如果与最先进的隔热结构相结合，可以实现背景有限的性能。通过将SMU热释电器件与雷神/TI系统公司生产的最先进的热隔离结构和读出电路相结合，将制造出高探测率热释电成像仪。必须处理和解决系统层面的各种问题，包括工艺兼容性、电气兼容性和系统品质因数。为了解决YBaCuO的电兼容性问题，可以通过调整其含氧量来降低YBaCuO的电阻损耗。工艺兼容性问题的解决方法是为YBaCuO找到与CMOS兼容的合适电极金属，并设计一种将YBaCuO沉积和光刻原理与雷神/TI系统公司为隔热结构开发的微机械加工技术相结合的制造工艺。几个品质因数，如热释电系数、热释电品质因数、响应率、比探测率、噪声，将用于评估焦平面阵列的性能。热释电特性和噪声机制，限制了探测器的探测率，是高隔热程度的独特特征，将被研究。在成功完成焦平面阵列一级的集成后，将尝试进行系统集成，以实现完整的红外相机。这项工作将实现从基础研究到设备概念再到系统集成的全方位工程流程，从而开发出性能和成本都无法超越的完整的非制冷红外成像仪。***

9800062 Butler This proposal concerns the investigation and development of high detectivity pyroelectric infrared imagers operating at room temperature. Previous work supported by the National Science Foundation and Army Research Office has shown that semiconducting, thin film YBaCuO possesses a high pyroelectric coefficient at room temperature, two hundred times greater than other thin film materials. This enables high detectivity pyroelectric thermal detectors to be fabricated on micromachined thermal isolation structures integrated on CMOS read-out circuitry, since the amorphous semiconducting phase of YBaCuO, used in these imaging devices, is deposited at ambient temperature with no need of high temperature post-annealing. It has been demonstrated by researchers at Southern Methodist University (SMU) that surfacemicromachined Nb/YBaCuO/Nb capacitor structures are capable of exhibiting pyroelectric coefficients in the range of 65 nC/K cm2 without an externally applied electric field and in the absence of prior poling. When poled, the pyroelectric coefficient was found to increase to 18 (C/cm2-K. If integrated with state-of-the-art thermal isolation structures, background limited performance is achievable. High detectivity pyroelectric imagers will be fabricated by combining the SMU pyroelectric devices with the state-of-the-art thermal isolation structures and read-out circuitry produced by Raytheon/TI Systems. Various issues at the systems level must be addressed and solved including process compatibility, electrical compatibility, and system figures of merit. To solve the electrical compatibility issue, the resistive loss of YBaCuO will be decreased by adjusting its oxygen content. Process compatibility issue will be addressed by finding an appropriate electrode metal for YBaCuO that is CMOS compatible and designing a fabrication process that incorporates the principles of YBaCuO deposition and lithography with micromachining technology developed for the thermal isolation structu res at Raytheon/TI Systems. Several figures of merit, such as pyroelectric coefficient, pyroelectric figure of merit, responsivity, specific detectivity, noise, will be used to assess performance at the focal plane array level. The pyroelectric properties and the noise mechanisms, which limit the detectivity and are uniquely characteristic of the high degree of thermal isolation, will be investigated. Upon successful completion of integration at the focal plane array level, a systems-integration will be attempted towards a complete IR camera. The proposed work will realize a full range of engineering processes from basic research to device concepts to systems integration, thereby developing a complete uncooled IR imager, unsurpassed in performance and cost. ***