Fabrication of Micromachined SnO2 Based MOS Gas Sensor with Inbuilt Microheater for Detection of Methanol
This paper presents a simple method to fabricate a vertical closed membrane structured gas sensor on silicon substrate using micromachining technology for methanol detection at lower concentration. An undoped tin dioxide thin film is deposited by DC magnetron sputtering technique on a pair of gold i...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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IFSA Publishing, S.L.
2016-09-01
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| Series: | Sensors & Transducers |
| Subjects: | |
| Online Access: | http://www.sensorsportal.com/HTML/DIGEST/september_2016/Vol_204/P_2860.pdf |
| Summary: | This paper presents a simple method to fabricate a vertical closed membrane structured gas sensor on silicon substrate using micromachining technology for methanol detection at lower concentration. An undoped tin dioxide thin film is deposited by DC magnetron sputtering technique on a pair of gold interdigitated microelectrodes of dimension 820 µm ´ 925 µm. A meander shaped platinum micro heater of dimension 1025 µm ´ 1000 µm is incorporated to provide optimum operating temperature (about 350 0C) for sensing operation. Energy dispersive X-ray spectroscopy is done to confirm the chemical composition of the sensor. Temperature coefficient of resistance of the inbuilt micro heater is found to be 0.0941 /0C. The sensor resistance shows significant change when micro heater voltage is varied from 1.5 V-3 V. I-V analysis of the sensor is carried out at 25 0C, 50 0C and 75 0C, and shifts in current through the sensor at different temperatures are observed. I-V characterization is also carried out at different methanol concentration levels (50-110 ppm) and it is found that at minimum 80 ppm, the sensor exhibits promising result. The response time and recovery time of the sensor is found to be 160 s and 167 s respectively. |
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| ISSN: | 2306-8515 1726-5479 |