Optimization of CMOS-MEMS Thermopile Infrared Microsensors
| Autor: | Wei-Jiun Chen, 陳威竣 |
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| Rok vydání: | 2014 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 102 This study presents the optimization of the signal-to-noise ratio of 0.8 μm standard CMOS polysilicon/Al thermopile infrared sensors with the same area of 1.2 mm x 1.2 mm and the same post MEMS process. The performance of the sensors were also evaluated by the measurement results of completed thermopile sensors and the simulated results of ANSYS FEA simulation. The thermopile with different length thermocouples and the thermopile with different thermocouple pairs were simulated by using ANSYS FEA simulation to evaluate temperature distributions and temperature difference between hot junction and cold junction. The completed thermopile sensors consist of 64, 96, 160 poly/Al thermocouple pairs were fabricated by COMS-MEMS process. The solid conductance of each sensor was evaluated according to the ANSYS simulation of the temperature distribution on the thermopiles. The trend of sensor output voltage was expected by the simulation and measurement. The SNR of the thermopiles was estimated as the ratio of sensor output voltage and noise. Finally, the optimization of the thermopiles with different thermocouple pairs could be found out by the SNR trend of the thermopiles The completed thermopile sensors consist of 64, 96, 160 poly/Al thermocouple pairs with the resistance of 39.5, 85.4, 230 kΩ, respectively. The corresponding responsivity and thermal time constant were 31.27, 45.9, 71.05(V/W), 11ms in atmosphere and 61.07, 88.69, 137.56(V/W), 22ms at the pressure of 37 mTorr as target temperature is 200℃, respectively. According to the measurement and the ANSYS simulation results, it shows that the thermopile sensor with 64 pairs has relatively higher SNR among the different thermopiles. The D* of 64 pairs thermopile are 1.47×108 in atmosphere and 2.87×108(cm Hz1/2/W) at the pressure of 37 mTorr, respectively. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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