Micro ethanol sensors with a heater fabricated using the commercial 0.18 μm CMOS process.
The study investigates the fabrication and characterization of an ethanol microsensor equipped with a heater. The ethanol sensor is manufactured using the commercial 0.18 µm complementary metal oxide semiconductor (CMOS) process. The sensor consists of a sensitive film, a heater and interdigitated electrodes. The sensitive film is zinc oxide prepared by the sol-gel method, and it is coated on the interdigitated electrodes. The heater is located under the interdigitated electrodes, and it is used to supply a working temperature to the sensitive film. The sensor needs a post-processing step to remove the sacrificial oxide layer, and to coat zinc oxide on the interdigitated electrodes. When the sensitive film senses ethanol gas, the resistance of the sensor generates a change. An inverting amplifier circuit is utilized to convert the resistance variation of the sensor into the output voltage. Experiments show that the sensitivity of the ethanol sensor is 0.35 mV/ppm.
Department of Mechanical Engineering, National Chung Hsing University, Taichung 402, Taiwan. cldai@dragon.nchu.edu.tw.
Wei-Zhen
WZ
Liao
Ching-Liang
CL
Dai
Ming-Zhi
MZ
Yang
D003217:Conductometry / Q000295:instrumentation*; D017097:Electric Impedance; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D000431:Ethanol / Q000032:analysis* / Q000737:chemistry; D006361:Heating / Q000295:instrumentation*; D008904:Miniaturization; D012666:Semiconductors; D014159:Transducers
D000431:Ethanol