| 摘要 |
PURPOSE:To obtain a sensor for gaseous NOx which can be used at a room temp. as well by installing a Langmuir-Blodgett film for adsorbing the gaseous NOx between a gate insulating film and gate electrode of an insulated gate type FET. CONSTITUTION:The MOSFET is prepd. and the gate part is held formed with only the insulating film 1 consisting of an SiO2 film. A thin film of Si3N4 or org. high polymer is usable in place of SiO2. The Langmuir-Blodgett film is built-up on the film 1 and is rested in the flow of iodine vapor diluted by the gaseous nitrogen. This resting is executed dividedly several times for about several tens seconds until the film exhibits a prescribed resistance value to form the sensitive film 3. The gate electrode 2 is formed on the film 3. The gaseous NOx diffuses into the gate electrode 2 and is adsorbed in the sensitive film 3 when such gas sensor is rested in a gas contg. the NOx. The interfacial potential corresponding to the amt. of the gas adsorbed is generated between the insulating film 1 and the sensitive film 3.
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