Xd. Wang et al., MONOLITHIC THIN-FILM METAL-OXIDE GAS-SENSOR ARRAYS WITH APPLICATION TO MONITORING OF ORGANIC VAPORS, Sensors and actuators. B, Chemical, 28(1), 1995, pp. 63-70
This paper presents the study of eight-element gas-microsensor arrays
that have been developed by silicon-based microfabrication and microma
chining techniques combined with the reactive sputtering and etching o
f tin(IV) oxide or tin dioxide, zinc oxide, and tungsten trioxide. The
mixed metal-oxide array has been fabricated on a 3 mm x 3 mm silicon
chip. The process-compatibility problem encountered when delineating m
ultiple sensing materials into a single device is resolved by combinin
g ion-beam milling, 'lift-off', and wet chemical etching methods. The
microsensor arrays are used to monitor benzene, toluene, and methanol
and to analyze benzene-toluene mixtures with various multivariate cali
bration methods. The range of sensitivity of the arrays is tested with
concentrations between 50 and 500 ppm of the organic vapors. Predicti
on errors for benzene-toluene mixtures are 29.8 ppm and 17.0 ppm, resp
ectively, using projection pursuit regression.