Tin oxide micro gas sensor for detecting CH3SH

doi:10.1016/0925-4005(95)85102-X

Sensors and Actuators B: Chemical

Volume 25, Issues 1–3, April 1995, Pages 478-481

https://doi.org/10.1016/0925-4005(95)85102-X Get rights and content

Abstract

Highly sensitive and mechanically stable micro gas sensors have been made using microfabrication and micromachining techniques. The sensing material used to detect offensive CH₃SH gas is 1 wt.% Pd-doped, 2000A˚thick SnO₂ deposited by r.f. magnetron sputtering. The optimum operating temperature of the sensor is 250°C, and the corresponding heater power is about 55 mW. Excellent thermal insulation of the membrane is achieved by the use of a double-layer structure of 0.2 μm thick silicon nitride and 1.4 μm thick phosphosilicate glass (PSG) prepared by low-pressure chemical-vapour deposition (LPCVD) and atmospheric-pressure chemical-vapour deposition (APCVD), respectively. The sensors are mechanically stable enough to endure at least 43 200 heat cycles between room temperature and 350°C.

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