SENSITIVITY CONTROL OF SNO2 BY MORPHOLOGY OF THIN-FILM

Gas sensing properties of SnO2 thin films with different microstructur es fabricated by RF magnetron sputtering method were investigated over the temperature range 623-773 K, using the same concentration of H-2 or CH4 containing dry air as test gases. The SnO2 thin film with dense structure gave much larger conductivity change in contact with 3600 p pm H-2 containing dry air than with the same concentration of CH4 over 623-773 K. The thin film with columnar structure showed that the cond uctivity in contact with 3600 ppm CH4 containing air was approximately equal to that with the same concentration of H-2 at 773 K. The morpho logical control of the thin film results in a notable change in gas se nsing properties of the SnO2 thin film. (C) 1997 Elsevier Science B.V.