Js. Lee et al., FABRICATION OF A MICRO CATALYTIC GAS SENSOR USING THIN-FILM PROCESS AND SI ANISOTROPIC ETCHING TECHNIQUES, Sensors and actuators. B, Chemical, 45(3), 1997, pp. 265-269
A new micro catalytic gas sensor for detecting inflammable gases was f
abricated on a Si wafer by thin film deposition and Si anisotropic etc
hing. The size of the fabricated sensor was 3.25 x 2.20 mm(2). The sen
sor was designed to consist of a catalyst with high surface area and a
heater with high temperature coefficient of resistance (TCR) in order
to acquire high sensitivity to gases of interest. The TCR of the sens
or was found to be 3844 ppm degrees C-1. Sensitivities to methane and
butane gases were 2.2 mV 1000 ppm(-1) and 8.9 mV 1000 ppm(-1), respect
ively. The optimum applied Wheatstone bridge power was varied in the r
ange from 350 to 400 mW, being much smaller than those of commercial p
ellistors. It was also found that sensitivities to methane and butane
gas were decreased by increasing humidity. (C) 1997 Elsevier Science S
.A. All rights reserved.