Research On High Absorption Heat Conduction MEMS Thermopile Infrared Detector Technology

Infrared detection technology has a wide and important application in military and civil fields.In the COVID-19 Novel Coronavirus epidemic,in the face of the temperature measuring equipment with MEMS thermopile infrared detector as the core device in the sensor accuracy,output,performance and other bottlenecks,as well as the current situation of the late start of domestic infrared detector research,this paper proposed the research significance of MEMS thermopile infrared detector.The advantages of MEMS thermopile infrared detector,such as non-contact temperature measurement at room temperature,low cost,no chopper,no external bias voltage and simple output circuit,are summarized.The important role of MEMS thermopile infrared detector in epidemic prevention and control is defined.In this paper,a MEMS thermopile infrared detector with high absorption-thermal conductivity membrane structure is designed.The main characteristics of the detector are: the two-layer thermocouple stacking structure is used to improve the duty ratio of the device;the thermal conduction structure of the detector is designed,and the low thermal conductor-electrically insulating silicon nitride material is directly introduced to the hot end of the double-layer thermocouple.An additional wide spectrum and high absorption nanoforest absorber is introduced into the detector,and its detection performance is significantly enhanced after the addition of the absorber.Then,based on the process involved in the research and development of thermally-conducting MEMS thermopile infrared detector,the design integration and optimization of the overall process flow are carried out,and finally a set of completed process flow scheme is formed.The mapping work needed for this flow sheet is completed by L-Edit layout drawing software.Then,we work on the research and development of MEMS thermopile infrared detector performance parameter test,VT response characteristic test.And based on the problems existing in the traditional blackbody test system,we put forward a laser testing solution.Final,the experimental verification shows that the laser test plan is a good way to avoid error introduced by chopper.Finally,from the aspect of infrared absorption layer,based on plasma polymerization technology,we design and process a nanoforest absorber with wide spectrum and advantage of highly compatible with CMOS.By using FDTD for spectrum simulation of this structure,we know the output voltage of the thermopile detector after the integration of nanoforest absorber is obviously higher than that of the original thermopile detector.