title: Fabrication and Characterization of a Micro Methanol Sensor Using the CMOS-MEMS Technique.
abstract: A methanol microsensor integrated with a micro heater manufactured using the complementary metal oxide semiconductor (CMOS)-microelectromechanical system (MEMS) technique was presented. The sensor has a capability of detecting low concentration methanol gas. Structure of the sensor is composed of interdigitated electrodes, a sensitive film and a heater. The heater located under the interdigitated electrodes is utilized to provide a working temperature to the sensitive film. The sensitive film prepared by the sol-gel method is tin dioxide doped cadmium sulfide, which is deposited on the interdigitated electrodes. To obtain the suspended structure and deposit the sensitive film, the sensor needs a post-CMOS process to etch the sacrificial silicon dioxide layer and silicon substrate. The methanol senor is a resistive type. A readout circuit converts the resistance variation of the sensor into the output voltage. The experimental results show that the methanol sensor has a sensitivity of 0.18 V/ppm.
authors.affiliation: Department of Mechanical Engineering, National Chung Hsing University, Taichung 402, Taiwan. fongjeff@livemail.tw.
authors.forename: Chien-Fu
authors.initials: CF
authors.lastname: Fong
authors.affiliation: Department of Mechanical Engineering, National Chung Hsing University, Taichung 402, Taiwan. cldai@dragon.nchu.edu.tw.
authors.forename: Ching-Liang
authors.initials: CL
authors.lastname: Dai
authors.affiliation: Department of Mechanical and Electro-Mechanical Engineering, Tamkang University, Tamsui 251, Taiwan. ccwu@mail.tku.edu.tw.
authors.forename: Chyan-Chyi
authors.initials: CC
authors.lastname: Wu
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry; D000432:Methanol / Q000737:chemistry*; D055617:Micro-Electrical-Mechanical Systems / Q000379:methods*; D010087:Oxides / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D010087:Oxides; D013440:Sulfides; C034939:cadmium sulfide; D000432:Methanol
keywords: cadmium sulfide; heater; methanol sensor; tin dioxide