热机偏转红外探测关键技术研究

发布时间：2018-02-07 16:28

  本文关键词： 红外探测 微悬臂梁 有基底的红外焦平面阵列 氮化硅　出处：《西安工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：红外探测器在军事和民用、医疗、安全防卫等领域应用非常广泛,成为各国高科技成像追逐的热点,尤其是近年来对采用光学读出系统同时选用微悬臂梁结构焦平面阵列的红外成像技术做了多项研究。本文提出的是一种使用光学读出方式的热型红外探测系统,其中红外探测器件是基于双材料的热机偏转原理设计出一种微悬臂梁结构的探测敏感单元。文中重点对氮化硅薄膜进行了应力特性和红外特性方面的研究,同时研究了红外探测器件的制作工艺。获得主要结果如下；1)设计基于双材料梁热机偏转的红外探测器件：以K9玻璃为基底,器件阵列为120×120,单元尺寸为40μm×40μm。红外探测器件的结构较简单,增加了反光板的面积和红外辐射的吸收面积。2)研究氮化硅薄膜的应力特性、红外吸收特性和刻蚀特性：实验中改变PECVD的射频功率、反应压强等工艺参数,氮化硅薄膜表现出不同的应力。薄膜厚度约为600nm时,压应力的最小值是65MPa;调整PECVD射频功率、反应时间等工艺参数,氮化硅厚度约600nm时,薄膜的相对吸收强度最大约为4.0；调整ICP的功率、反应压强等工艺参数,薄膜最大刻蚀速率达到14.5nm/s, Si3N4/EPG533最大刻蚀选择比接近4.25。3)研究探测器件的制造工艺：采用光刻技术、磁控溅射技术和PECVD技术、ICP刻蚀技术等多种MEMS工艺分别制备牺牲层、反光层和红外吸收层。实验中最佳工艺参数为：制备金膜层时,溅射功率80W,氩气流量85mL/min,气压1Pa；制备氮化硅薄膜时,PECVD沉积温度250℃C,射频功率180W,反应压强60Pa, SiH4流量40mL/min, N2流量60mL/min;刻蚀氮化硅薄膜时,ICP功率300W、偏压功率70W、反应压强30mTrr、SF6流量30mL/min、O2流量13 mL/min。
[Abstract]:Infrared detectors are widely used in military, civil, medical, security and defense fields, and have become a hot spot for high-tech imaging in various countries. In particular, in recent years, many studies have been done on infrared imaging technology with optical readout system and microcantilever structure focal plane array. In this paper, a thermal infrared detection system using optical readout mode is proposed. The infrared detector is based on the thermal mechanical deflection principle of two materials to design a kind of detection sensitive unit of the micro-cantilever structure. The stress and infrared characteristics of the silicon nitride thin film are studied in this paper. At the same time, the fabrication technology of infrared detector is studied. The main results are as follows: (1) the infrared detector based on bimaterial beam thermal mechanical deflection is designed, which is based on K9 glass. The device array is 120 脳 120 and the unit size is 40 渭 m 脳 40 渭 m. The structure of the infrared detector is simple, which increases the area of the reflector and the absorption area of infrared radiation. Infrared absorption and etching characteristics: the silicon nitride film exhibits different stresses by changing the RF power and reaction pressure of PECVD. When the thickness of the film is about 600 nm, the minimum compressive stress is 65 MPA, and the RF power of PECVD is adjusted. When the thickness of Si _ 3N _ 4 is about 600nm, the maximum relative absorption intensity of the film is about 4.0, and the process parameters such as the power of ICP, reaction pressure and so on are adjusted. The maximum etching rate of the thin film is 14.5 nm / s and the maximum etching selection ratio of Si3N4/EPG533 is nearly 4.25.3) the fabrication process of the detector is studied. The sacrificial layers are prepared by various MEMS processes, such as photolithography, magnetron sputtering and PECVD etching. Reflective layer and infrared absorption layer. The optimum technological parameters in the experiment are: when the gold film is prepared, Sputtering power is 80W, ar flow rate is 85mL / min, pressure is 1Pa.The deposition temperature of silicon nitride film is 250 鈩，

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