A TECHNIQUE FOR SUPPRESSING ETHANOL INTERFERENCE EMPLOYING SEEBECK EFFECT DEVICES WITH CARRIER CONCENTRATION MODULATION

Thin sputtered indium oxide films with an additive deposited on the ha lf of their surface are considered as Seebeck effect devices for sensi ng of methane and ethanol. The electron concentration of the oxide fil m is controlled with an applied voltage perpendicular to the film with the use of a buried gate under it, in the same way the channel conduc tance in a MOS device is controlled by the gale voltage. Due to the di fferent chemisorption mechanisms of methane and ethanol, a gate voltag e modulating the free electron concentration of the oxide film enhance s sensitivity to methane, whereas it does not influence sensitivity to ethanol. (C) 1997 Elsevier Science S.A.