Analysis and Design of Thermoelectric Infrared Microsensor

In this study, a novel thermoelectric infrared microsensor (TIMS) is designed by using commercial CMOS IC processes with subsequent bulk-micromachining process. This microsensor has the advantages of high fill factor, low noise equivalent temperature difference (NETD), and simple fabrication process. The key feature is that thermocouple cantilever beams with low solid thermal conductance have been placed under the membrane of thermoelectric infrared microsensor. In order to improve the performance of the infrared sensor, the basic physical characteristics of this sensor have been analyzed. Finite element analysis is used to simulate the electro-thermo-mechanical behavior of the device and to demonstrate the feasibility of our design. Besides, a method for manufacturing the infrared microsensor is also provided and the performance of the presented design has been examined. The analytical results concluded that lowering down the number of the thermocouples does not affect the responsivity but do reduce the total resistance. Also, the detectivity and responsivity are obviously increased for the proposed TIMS. Finally, the deviation between the theoretical and the simulated results is discussed.© 2003 ASME