一种交叉式圆形MEMS热电堆红外探测器

Crossover Circular MEMS Thermopile Infrared Detector

微电子机械系统(MEMS)热电堆红外探测器是非接触测温仪、光谱仪、气体传感器等现代信息探测系统的核心工作器件。研制了一种交叉式排布的圆形热电堆结构,其热偶条形状由传统矩形调整为直角梯形以降低探测器电阻,热端通过交叉式排布延伸至中心温度集中区,同时增大冷端欧姆接触面积并覆盖反射层以降低冷端温度,有效地增大了冷热端温度梯度。测试结果显示,优化后的交叉式圆形MEMS热电堆探测器距黑体辐射面3 cm处响应电压为22.673 mV,响应率为47.5 V/W,探测率为1.01×10^(8)cm·Hz^(1/2)·W^(-1),相对于传统圆形热电堆探测器的18.649 mV、39.1 V/W和0.852 cm·Hz^(1/2)·W^(-1)分别提升了21.57%、21.48%和18.5%。给出了热电堆探测器结构设计、仿真结果、制作工艺以及测试结果,为热电堆红外探测器的优化设计提供了参考。

Micro-electromechanical system(MEMS)thermopile infrared detectors are the core working devices for modern information detection systems such as non-contact thermometer,spectrometer and gas sensor.A cross-arranged circular thermopile structure was developed.The thermocouple strip shape of the thermopile was adjusted from traditional rectangle to right-angle trapezoid to reduce the detector resistance,and the hot end was extended to the central temperature concentration area by cross arrangement,while the cold end Ohmic contact area was increased and the detector was covered with a reflective layer to reduce the cold end temperature,effectively increasing the temperature gradient between the hot and cold ends.The test results show that the optimized crossed circular MEMS thermopile detector has a response voltage of 22.673 mV,a responsivity of 47.5 V/W and a detectivity of 1.01×10^(8)cm·Hz^(1/2)·W^(-1)at a distance of 3 cm from the blackbody radiation surface.Compared with 18.649 mV,39.1 V/W and 0.852 cm·Hz^(1/2)·W^(-1)of the conventional circular thermopile detector,the increases are 21.57%,21.48%and 18.5%,respectively.The structural design,simulation results,fabricating process and test results of the thermopile detector were presented,providing a reference for the optimal design of thermopile infrared detectors.