【作者】 王彬；

【导师】 陈四海； 赖建军；

【作者基本信息】 华中科技大学 ， 光学工程， 2012， 博士

【摘要】 非致冷红外探测器/微测辐射热计作为属于第三代的基于微机电系统MEMS技术的红外探测器,由于具有体积小、重量轻、功耗低、易携带、非致冷等优点,在工业、农业、国防、医疗、交通、环境保护等诸多领域具有非常广泛的应用前景。提高微测辐射热计的灵敏度和探测性能是从事这一领域的研究者一致努力追求的目标。本论文从微测辐射热计的工作原理、结构设计、仿真分析、材料制备、器件制作和性能测试等方面展开了一系列比较深入的研究。通过制备具有高电阻温度系数(TCR)的氧化钒薄膜、掺氮氧化钒薄膜和黑金吸收层并利用微加工技术手段分别将它们集成在探测器上,提高了微测辐射热计的性能。主要研究内容和成果综述如下：(1)探索和发现了采用脉冲直流磁控溅射法制备的氧化镍铬NiCr2O4薄膜所具有的电学特性和光学特性。该条件下制备的NiCr2O4材料特性不同于高压氧化等条件下所制备的材料特性。研究发现,该薄膜在室温到100摄氏度范围内具有半导体-绝缘体电学相变特性；在3-5μm高温红外波段有很好的红外吸收效果,具有潜在的红外市场领域应用价值。(2)开展了氧化钒热敏薄膜材料和器件研究。采用离子束溅射法制备了在室温附近具有高TCR氧化钒薄膜。利用扫描电镜、原子力显微镜和X射线衍射等技术手段对该薄膜进行了表面形貌、晶粒尺寸等属性观察和分析。设计和制作了基于多孔硅牺牲层的64×2阵列的氧化钒微测辐射热计。采用薄膜矩阵和有限元方法仿真分析了该探测器的光学、力学、热学、电学等性能。最后对该探测器进行了系统测试。(3)采用电阻蒸发方法制备了红外吸收黑金薄膜。对该薄膜进行了表面形貌研究并对其反射率进行了测试。通过建立黑金链状结构模型与复电介质函数Drude-Zener模型等效成等效电路,对黑金薄膜材料的光学性质进行了数值计算。通过对比集成和未集成黑金薄膜的氧化钒微测辐射热计证实集成该红外吸收层的探测器具有显著改善的探测性能的效果。(4)提出在制备过程中引入少量氮气制备掺氮氧化钒薄膜作为提高TCR的方法,并且采用脉冲磁控溅射法制备了与微测辐射热计兼容性较好的高TCR的掺氮氧化钒薄膜。设计和制作了64×2阵列的基于表面牺牲层技术的掺氮氧化钒微测辐射热计,通过薄膜矩阵和有限元方法仿真了该探测器的光学、力学、热学、电学等性能。最后对该探测器进行了的系统测试,测试得到的探测率达到1.39×109cmHz1/2/W。更多还原

【Abstract】 As the third-generation infrared detector based on Micro-Electro-Mechanical-System (MEMS) technology, uncooled infrared detector/microbolometer has a very wide application prospects in the many fields of industry, agriculture, defence, medical, transportation and environmental protection, owing to the advantages of small volume, light weight, low power consumption, portability and less expensive, etc. Improving the sensitivity and performance of uncooled infrared detectors is the goal that all researchers who engages in this aera keep pursuing. This thesis focuses on the key technologies of one kind of microbolometer based on vanadium dioxoide sensitive thin film. A series of intensive researches have been made including working principle, structural design, simulation and analysis, materials preparation, device fabrication and performance testing of the microbolometer. Bolometer performance has been improved by micromachining technology-the preparation and integration of high temperature coefficient of resistance (TCR) VOx, nitrogen-doped vanadium oxide and gold black of high infrared absorption, respectively. The main contents and achievements are summarized as follows:(1) The electrical and optical property of nickel chromium oxide-NiCr2O4thin film has been explored and prepared by using pulsed-dc magnetron sputtering method. The characteristic of NiCr2O4prepared by this method is different from those of material prepared under the conditions of high pressure oxidation. It’s been found that this thin film from room temperature to100degrees Celsius has properties of semiconductor-insulator electrical phase transition and good infrared absorption between3μm and5μm of high temperature infrared spectrum. It has potential application in the field of infrared market.(2) The thermal sensitive material and device of vanadium oxide thin film have been studied. The vanadium oxide thin film has high temperature coefficient of resistance at near room temperature which is prepared by ion beam sputtering. The properties of this film-surface morphology, grain size and other attributes are revealed by XRD, SEM and AFM technology.64×2array bolometer based on porous silicon sacrificial layer is designed and fabricated. The optical, mechanical, thermal and electrical performances of the detector are simulated and analyzed by the film matrix method and the finite element method. Finally, the detector system test is carried out.(3) Gold black thin film of high infrared absoption is prepared by resistive evaporation method. The surface morphology and reflectivity is measured. The optical property of gold black material is simulated by numerical computation by establishing model of gold black chain structure which is equivalent to the equivalent circuit of Drude-Zener model. Gold black film is integrated into vanadium oxide microbolometer as infrared absorber. Comparing with bolometer without gold black, this bolometer with gold black has a better detection.(4) In the preparation process of nitrogen-doped vanadium oxide thin film by introducing a small amount of nitrogen gas is put forward as a way to improve TCR. Nitrogen-doped vanadium oxide thin film of high TCR is prepared by pulsed-dc magnetron sputtering method.64×2array nitrogen-doped vanadium oxide microbolometer based on surface sacrificial layer technology is designed and fabricated. The optical, mechanical, thermal and electrical performances of the detector are simulated and analyzed by the film matrix method and the finite element method. The detector system testing shows that the detectivity of this bolometer has reached1.399×109cmHz1/2/W.更多还原