Research on Self-Test Method Based on Thermopile Infrared Sensor

In this paper, a self-test method is proposed for the thermopile infrared (IR) detector. To verify the validity of the self-test method, a high-performance thermopile infrared detector based on XeF2 front-side dry etching is designed, fabricated and characterized. And a platinum heater is fabricated in the absorption area of the thermopiles to replace the traditional IR radiation to monitor the IR performance of the detector. IR radiation sensing is carried out to characterize the $\mathbf{IR}$ performance of the thermopile IR detector. The testing results show that the detector achieves a relatively high responsivity of 160.03 V/W and detectivity of $\pmb{9.75\times 10^{7}}$ cm $\mathbf{Hz}^{\pmb{1/2}}\pmb{\cdot \mathrm{W}^{-1}}$ and an extremely short response time of 2.5 ms in the air at room temperature. Moreover, the self-test measurement is conducted by applying a voltage to the heater. Compared with the use of complex equipment such as blackbody and chopper to detect the performance of thermopile infrared detectors, this method has obvious convenience and simplicity, which provides an effective way for performance monitoring of thermal-based devices.