Sol-Gel Zinc Oxide Humidity Sensors Integrated with a Ring Oscillator Circuit On-a-Chip
The study develops an integrated humidity microsensor fabricated using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS) process. The integrated humidity sensor consists of a humidity sensor and a ring oscillator circuit on-a-chip. The humidity sensor is composed of a sensitive...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2014-10-01
|
| Series: | Sensors |
| Subjects: | |
| Online Access: | http://www.mdpi.com/1424-8220/14/11/20360 |
| _version_ | 1811304044728156160 |
|---|---|
| author | Ming-Zhi Yang Ching-Liang Dai Chyan-Chyi Wu |
| author_facet | Ming-Zhi Yang Ching-Liang Dai Chyan-Chyi Wu |
| author_sort | Ming-Zhi Yang |
| collection | DOAJ |
| description | The study develops an integrated humidity microsensor fabricated using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS) process. The integrated humidity sensor consists of a humidity sensor and a ring oscillator circuit on-a-chip. The humidity sensor is composed of a sensitive film and branch interdigitated electrodes. The sensitive film is zinc oxide prepared by sol-gel method. After completion of the CMOS process, the sensor requires a post-process to remove the sacrificial oxide layer and to coat the zinc oxide film on the interdigitated electrodes. The capacitance of the sensor changes when the sensitive film adsorbs water vapor. The circuit is used to convert the capacitance of the humidity sensor into the oscillation frequency output. Experimental results show that the output frequency of the sensor changes from 84.3 to 73.4 MHz at 30 °C as the humidity increases 40 to 90%RH. |
| first_indexed | 2024-04-13T07:58:54Z |
| format | Article |
| id | doaj.art-46efabb0b4f0435b9832be16892c3000 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-13T07:58:54Z |
| publishDate | 2014-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-46efabb0b4f0435b9832be16892c30002022-12-22T02:55:19ZengMDPI AGSensors1424-82202014-10-011411203602037110.3390/s141120360s141120360Sol-Gel Zinc Oxide Humidity Sensors Integrated with a Ring Oscillator Circuit On-a-ChipMing-Zhi Yang0Ching-Liang Dai1Chyan-Chyi Wu2Department of Mechanical Engineering, National Chung Hsing University, Taichung 402, TaiwanDepartment of Mechanical Engineering, National Chung Hsing University, Taichung 402, TaiwanDepartment of Mechanical and Electro-Mechanical Engineering, Tamkang University, Tamsui 251, TaiwanThe study develops an integrated humidity microsensor fabricated using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS) process. The integrated humidity sensor consists of a humidity sensor and a ring oscillator circuit on-a-chip. The humidity sensor is composed of a sensitive film and branch interdigitated electrodes. The sensitive film is zinc oxide prepared by sol-gel method. After completion of the CMOS process, the sensor requires a post-process to remove the sacrificial oxide layer and to coat the zinc oxide film on the interdigitated electrodes. The capacitance of the sensor changes when the sensitive film adsorbs water vapor. The circuit is used to convert the capacitance of the humidity sensor into the oscillation frequency output. Experimental results show that the output frequency of the sensor changes from 84.3 to 73.4 MHz at 30 °C as the humidity increases 40 to 90%RH.http://www.mdpi.com/1424-8220/14/11/20360humidity sensorring oscillator circuitzinc oxide nanowire |
| spellingShingle | Ming-Zhi Yang Ching-Liang Dai Chyan-Chyi Wu Sol-Gel Zinc Oxide Humidity Sensors Integrated with a Ring Oscillator Circuit On-a-Chip Sensors humidity sensor ring oscillator circuit zinc oxide nanowire |
| title | Sol-Gel Zinc Oxide Humidity Sensors Integrated with a Ring Oscillator Circuit On-a-Chip |
| title_full | Sol-Gel Zinc Oxide Humidity Sensors Integrated with a Ring Oscillator Circuit On-a-Chip |
| title_fullStr | Sol-Gel Zinc Oxide Humidity Sensors Integrated with a Ring Oscillator Circuit On-a-Chip |
| title_full_unstemmed | Sol-Gel Zinc Oxide Humidity Sensors Integrated with a Ring Oscillator Circuit On-a-Chip |
| title_short | Sol-Gel Zinc Oxide Humidity Sensors Integrated with a Ring Oscillator Circuit On-a-Chip |
| title_sort | sol gel zinc oxide humidity sensors integrated with a ring oscillator circuit on a chip |
| topic | humidity sensor ring oscillator circuit zinc oxide nanowire |
| url | http://www.mdpi.com/1424-8220/14/11/20360 |
| work_keys_str_mv | AT mingzhiyang solgelzincoxidehumiditysensorsintegratedwitharingoscillatorcircuitonachip AT chingliangdai solgelzincoxidehumiditysensorsintegratedwitharingoscillatorcircuitonachip AT chyanchyiwu solgelzincoxidehumiditysensorsintegratedwitharingoscillatorcircuitonachip |