STTR Phase I: Advanced Uncooled Infrared Detectors at the Nano-Scale

这个小型企业技术转移一期项目旨在开发高灵敏度和廉价的非冷却微辐射热计，使用超薄金属、金属氧化物或半金属薄膜。这些微辐射热计对于便携式夜视设备和其他需要噪声等效温差（NETD）小于20 mK的热成像应用具有吸引力。我们已经展示了由二氧化硅/Si3N4/SiO2悬臂上的钛薄膜微制造的金属微辐射热计，其负温度电阻系数（TCR）高达- 0.67%/K（高于体钛薄膜）。NETD约为18 mK，噪声比氧化钒膜低1/f。使用替代金属、金属氧化物或半金属，TCR可以进一步提高到大于2%/K的值。此外，薄膜金属或半金属微辐射热计具有低噪声特性和其他重要优点，包括简化的制造过程和较低的制造成本。该项目的更广泛的影响/商业潜力是实现低成本和高灵敏度的红外（IR）探测，这将允许在一些低端军事和民用应用中取代冷却的红外探测器，包括夜视、导航、生物辐射测量、目标识别、光谱学和热剖面。微辐射热计可以进一步缩小，以减少每个像素？在保持或提高机械强度的同时，可以更快地响应给定量的辐射。通过探索非制冷红外探测器的其他超薄膜材料，可以在制造过程中进一步提高制造成本、可靠性和均匀性。这项研究工作也将有助于我们进一步了解金属和半金属超薄膜的电学、光学、机械和热性能。拟议的活动扩大了代表性不足的群体的参与，因为参与的高级研究科学家属于代表性不足的群体。本科生参与该项目将提高国家科学基金？美国教育目标。最后，这个项目的结果将通过科学和工业杂志的出版物加以传播。

This Small Business Technology Transfer Phase I project aims to develop highly sensitive and inexpensive uncooled microbolometers using ultra-thin films of metals, metal oxides, or semi-metals. These microbolometers will be attractive for use in portable night vision devices and other thermal imaging applications that require a Noise Equivalent Temperature Difference (NETD) of less than 20 mK. We have already demonstrated metal microbolometers microfabricated from titanium thin films on SiO2/Si3N4/SiO2 cantilevers with a negative temperature coefficient of resistance (TCR) as high as - 0.67%/K (which is higher than that of bulk titanium films), with a NETD of approximately 18 mK and a 1/f noise lower than that of vanadium oxide films. The TCR can be further increased to values greater than 2%/K using alternative metals, metal oxides, or semimetals. Furthermore, thin film metallic or semimetallic microbolometers have low noise characteristics and other important advantages, including a simplified fabrication process and a lower manufacturing cost.The broader impact/commercial potential of this project is to achieve low-cost and high-sensitivity infrared (IR) detection with uncooled microbolometers, which will allow the replacement of cooled IR detectors in some low-end military and civilian applications, including night vision, navigation, biological radiometry, target discrimination, spectroscopy, and thermal profiling. Microbolometers can be further scaled down to reduce each pixel?s thermal mass, allowing a faster response to a given amount of radiation, while maintaining or improving mechanical strength. By exploring other ultra-thin film materials for uncooled IR detectors, the manufacturing cost, reliability, and uniformity can be further improved during the fabrication process. This research work will also help us further understand the electrical, optical, mechanical and thermal properties of ultrathin films of metals and semimetals. The proposed activity broadens the participation of underrepresented groups, since senior research scientists involved belong to underrepresented groups. Undergraduate involvement in this project will enhance NSF?s educational goals. Finally, the results of this project will be disseminated through publications in scientific and industry journals.