MEMS微桥结构设计与光刻工艺参数优化

发布时间：2018-02-01 19:19

本文关键词： 非制冷红外探测器光刻对准系统微桥结构　出处：《电子科技大学》2016年硕士论文　论文类型：学位论文

【摘要】：非制冷红外探测器的发展是从20世纪80年代开始的,因其具有成本低、无需制冷、可靠性高、可集成、工艺兼容性好等优点,在民用和军用市场得到了广泛应用。非制冷红外探测阵列芯片主要包括读出电路、热敏材料及微桥结构,利用光-热-电转换原理工作。MEMS结构的探测微桥能够有效降低探测单元的热传导,从而保证探测器在室温环境下有较高的灵敏度。所以,开展低热导微桥结构的研究对高性能非制冷焦平面探测器的研制具有重要意义。微桥结构的每个层次图形均通过光刻工艺实现,并且光刻工艺决定了探测器的关键尺寸,因此实验探索一套优化的光刻工艺是微桥结构探测器件制备的关键。本文的目标是利用MEMS技术,基于氧化钒材料开展的非制冷红外探测阵列的设计与制备,并且对半导体工艺中的光刻工艺提出优化。主要内容是:(1)分析非制冷红外探测器的工作原理、微桥结构特征、热学以及力学性能,根据仿真分析设计出参数不同的微桥结构,运用IntelliSuite软件对设计的微桥结构进行力学和热学仿真,分析仿真结果;仿真最佳结果:像元尺寸为25×25μm2,桥腿宽度为0.9μm。(2)实际制备出所设计的微桥结构,并与仿真结果进行对比,观察其力学稳定性;本文所设计的微桥结构参考了改良后的传统L型桥腿模型,采用了L型双悬臂梁结构。(3)在制备微桥结构的工艺中进行的优化及对其中的光刻工艺做出的改善。通过对金属薄膜表面形貌的判断,选用不同对准方式提高套刻精确性;根据湿法腐蚀的特点,改善光刻工艺涂胶方法,改善横向腐蚀现象。本文设计的微桥结构制备工艺主要包括光刻、刻蚀、CVD、PECVD等,采用L-edit软件完成各层的版图设计,然后在超净间环境下进行红外探测阵列的制备。设计了十种像元尺寸不同或桥腿宽度不同的单元微桥结构,建立其有限元分析模型进行热学和力学仿真,制备出热学性能、力学性能稳定平衡的微桥结构和探测阵列。
[Abstract]:The development of uncooled infrared detectors began in 1980s, because of its advantages of low cost, no need of refrigeration, high reliability, integration, good process compatibility and so on. Uncooled infrared detection array chips mainly include readout circuits, thermosensitive materials and microbridge structures. Using the principle of photothermal-electric conversion, the micro-bridge of MEMS structure can effectively reduce the thermal conduction of the detection unit, thus ensuring the detector has a high sensitivity at room temperature. The research of low thermal conductivity microbridge structure is of great significance to the development of high performance uncooled focal plane detector. And photolithography technology determines the key size of the detector, so exploring a set of optimized lithography process is the key to the fabrication of micro-bridge structure detector. The goal of this paper is to use MEMS technology. The design and preparation of uncooled infrared detector array based on vanadium oxide materials and the optimization of lithography technology in semiconductor process are proposed. The main content is to analyze the working principle of uncooled infrared detector. According to the simulation analysis, the micro-bridge structure with different parameters is designed. The mechanical and thermal simulation of the designed micro-bridge structure is carried out by using IntelliSuite software. Analysis of simulation results; The optimal simulation results are as follows: the pixel size is 25 脳 25 渭 m ~ 2 and the bridge leg width is 0.9 渭 m 路m ~ 2) the designed micro-bridge structure is fabricated and compared with the simulation results, and its mechanical stability is observed. The microbridge structure designed in this paper refers to the modified traditional L-shaped bridge leg model. The L-type double cantilever beam structure. 3) was used to optimize the fabrication process of the microbridge structure and to improve the lithography process. The surface morphology of the metal film was judged. Choosing different alignment methods to improve the accuracy of sleeve etching; According to the characteristics of wet etching, the coating method of lithography process is improved, and the transverse corrosion phenomenon is improved. In this paper, the fabrication technology of micro-bridge structure mainly includes lithography, etching, CVDV / PECVD and so on. The layout of each layer is designed with L-edit software, and then the infrared detection array is fabricated in super-clean environment. Ten kinds of cell microbridge structures with different pixel sizes or leg width are designed. The finite element analysis model was established for thermal and mechanical simulation, and the microbridge structure and detection array with stable balance of thermal and mechanical properties were prepared.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN215

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