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

这个小型企业技术转移第一阶段项目旨在开发使用金属、金属氧化物或半金属的超薄薄膜的高灵敏度和廉价的非制冷微测辐射热计。这些微测辐射热计非常适合用于便携式夜视设备和其他需要噪声当量温差(NETD)小于20MK的热成像应用。我们已经展示了在SiO_2/Si3N_4/SiO_2悬臂梁上由钛薄膜制成的金属微测辐射热计，其电阻负温度系数(TCR)高达-0.67%/K(高于块体钛薄膜)，NETD约为18mK，噪声比氧化钒薄膜低1/f。可以使用替代金属、金属氧化物或半金属将TCR进一步增加到大于2%/K的值。此外，薄膜金属或半金属微测辐射热计具有低噪声特性和其他重要优势，包括简化的制造工艺和较低的制造成本。该项目的更广泛的影响/商业潜力是利用非制冷微测辐射热计实现低成本和高灵敏度的红外探测，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、光谱和热成像。微测辐射热计可以进一步缩小尺寸，以减少每个像素的S热质量，从而在保持或提高机械强度的同时，对给定的辐射量做出更快的响应。通过探索其他用于非制冷红外探测器的超薄膜材料，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、机械和热学性质。拟议的活动扩大了任职人数不足的群体的参与，因为所涉高级研究科学家属于任职人数不足的群体。本科生参与这个项目将提高国家科学基金会S的教育目标。最后，该项目的成果将通过科学和工业期刊上的出版物传播。

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.