基于三维有限元模型的微测辐射热计TCR及电学性能研究

Research on TCR and Electrical Characteristics of Microbolometer Based on 3D Finite Element Analysis Model

摘要:

微测辐射热计结构的电阻温度系数（TCR）及其电阻值对非致冷红外焦平面探测器的性能有极大影响。基于精确的微测辐射热计三维模型，采用热电偶合有限元方法，分析了其电学特性，针对所建立模型，加载0.5~10μA的直流偏置电流，得到各偏置下的温度及电势相应特性，并由此获取了不同温度下结构的电阻值，进而推导出一定温度内整个模型的TCR，从而为后端读出电路的设计提供参考。最后对实际制备的器件进行测试，验证了该方法的可靠性。

Abstract:

Temperature coefficient of resistance (TCR) and its electrical characteristics of a microbolometer significantly affect its performance. In this paper, a three-dimensional model of a 25μm×25μm VO2 microbolometer was eatablished, and then its electrical characteristics were studied by dynamic thermoelectricity field-coupling Finite element analysis (FEA) method. DC bias current ranging from 0.5~10μA was loaded on the model so as to obtain the tempeature and electric potential characteristics under different biases. And also the resistance under different temperatures was gained and TCR of the whole model in a certain temperature range was derived. Tests were performed on facricated devices and the realiability of the proposed FEA method was verified.