双端梁MEMS热电堆红外探测器关键技术研究

发布时间：2018-04-18 10:38

本文选题：热电堆 + 双端梁结构　；参考：《中北大学》2016年博士论文

【摘要】：红外探测技术在军事和民用领域中有着广泛而重要的应用。红外探测技术的核心是红外探测器。热电堆红外探测器是红外探测器中的重要一种,是根据赛贝克效应原理工作的,由于其室温工作非制冷、光谱响应范围宽、无需斩波、成本低、输出电路简单等优势已成为当前红外技术领域的研究热点之一。本论文以红外探测器国内外发展现状为起点,总结分析出当前热电堆红外探测器在结构设计和制备加工工艺方面存在的问题；另以红外辐射理论为切入点,热电堆红外探测器工作原理为手段,深入分析器件的结构和材料组成等相关参数分别对探测器性能的影响；最后基于以上分析和总结提出一种高占空比的MEMS热电堆红外探测器,具体情况如下：(1)针对传统的基于四端梁结构的热电堆红外探测器占空比低的问题,论文提出一种基于双端梁结构的热电堆红外探测器,与传统的基于四端梁结构的探测器相比,基于双端梁结构的探测器器件尺寸可进一步缩小同时保持相对较高的响应率和探测率；(2)建立了基于热导通-电绝缘结构的热电堆红外探测器理论分析模型,从理论角度分析出接触热阻会降低探测器的性能。利用氮化硅(SiNx)材料高热导-电绝缘的特性,在探测器热结与吸收区之间及冷结与热沉之间设计并实现了双热导通结构,提高探测器的性能；(3)论文中的热电堆红外探测器采用氟化氙(XF2)干法各向同性刻蚀技术以形成微绝热腔体结构,然而此技术在过释放时容易导致探测器冷结和输出电极悬空而损坏器件,针对此问题在探测器中设计并实现了一种刻蚀阻挡结构以防止此情况的发生：经过以上努力,最终完成探测器的版图设计和流片加工工作,测试结果显示论文所提出的热电堆红外探测器的响应率和探测率远高于已报道的的基于四端梁结构的探测器,其响应率、探测率和响应时间分别达1151.14 V/W、4.15×108 cm Hz1/2/W、14.46 ms。同时论文对探测器的真空特性和温度响应特性也进行了测试,测试结果显示探测器具有较宽的响应范围和较高的温度响应灵敏度,因此该探测器也可作为真空度和温度传感器使用。此外利用等离子体再聚合技术制备出了不同形貌的纳米纤维森林结构；并探索了基于等离子体再聚合技术制备的黑硅作为红外吸收层材料的可行性,这种方法流程简单,又具有高度的灵活性、可调控性和可重复性,并且还与热电堆红外探测器的加工工艺有着高度的兼容性。
[Abstract]:Infrared detection technology has a wide range of important applications in military and civil fields.The core of infrared detection technology is infrared detector.Thermoelectric stack infrared detector is an important kind of infrared detector, which works according to the principle of Seebeck effect. Because of its uncooled temperature, wide spectrum response range, no chopping and low cost,The advantages of simple output circuit have become one of the research hotspots in the field of infrared technology.Based on the development of infrared detectors at home and abroad, this paper summarizes and analyzes the problems existing in the structure design and fabrication process of infrared detectors in thermoelectric reactor, and takes the infrared radiation theory as the breakthrough point.Based on the working principle of the thermoelectric reactor infrared detector, the influence of the structure and material composition of the device on the detector performance is analyzed. Finally, based on the above analysis and summary, a high duty cycle MEMS thermoelectric reactor infrared detector is proposed.The specific situation is as follows: (1) aiming at the problem of low duty cycle of traditional thermoelectric stack infrared detector based on four-end beam structure, this paper proposes a dual-end structure based thermoelectric reactor infrared detector, which is compared with the traditional four-end beam structure detector.A theoretical analysis model of thermoelectric stack infrared detector based on thermal-on-electric insulation structure is established, which can further reduce the size of detector devices and maintain a relatively high responsivity and detectivity.From the theoretical point of view, the contact thermal resistance will reduce the performance of the detector.Based on the characteristics of high thermal conductivity and electrical insulation of silicon nitride (SiNx) material, a double thermal conduction structure is designed and realized between the thermal junction and absorption zone of the detector and between the cold junction and the heat sink.In this paper, the thermoelectric stack infrared detector adopts xenon fluoride XF2) dry isotropic etching technique to form a micro-adiabatic cavity structure.However, this technique can easily cause the detector cold junction and the output electrode to be suspended and damage the device when it is overreleased. To solve this problem, a etching barrier structure is designed and implemented in the detector to prevent this from happening.Finally, the layout design of the detector and the fabrication of the wafer are finished. The test results show that the response rate and detection rate of the infrared detector proposed in this paper is much higher than that of the reported detector based on the four-end beam structure, and the response rate of the detector is much higher than that of the infrared detector based on the four-end beam structure.The detectivity and response time are 1151.14 V / W / W = 4.15 脳 10 ~ 8 cm Hz / 2 / W ~ (14. 46) Ms respectively.At the same time, the vacuum and temperature response characteristics of the detector are also tested. The test results show that the detector has a wide response range and a higher temperature response sensitivity.Therefore, the detector can also be used as vacuum and temperature sensors.In addition, nanofiber forest structures with different morphologies were prepared by plasma repolymerization, and the feasibility of using black silicon prepared by plasma repolymerization as infrared absorption layer material was explored.It also has high flexibility, controllability and repeatability, and has high compatibility with the processing technology of thermoelectric stack infrared detector.
【学位授予单位】：中北大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN215

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