| 摘要 |
PURPOSE:To obtain a small-sized and long-life gaseous oxygen sensor by laminating a solid electrolyte film consisting of a material which generates the electromotive force corresponding to the amt. of oxygen ions at a room temp. on a gate insulating film. CONSTITUTION:An impurity is diffused on a silicon substrate to form drain 2 and source 3 regions. The silicon surface between the drain 2 and the source 3 is a channel of an FET. An SiO2 oxide film 4 and an Si3N4 insulating film 5 are formed as the gate insulating film on said channel and further, the solid electrolyte film 6 is laminated thereon, then a metallic catalyst film 7 is formed as a gate electrode. The film thickness of the solid electrolyte 6 is preferably thinner to improve the electrical characteristics of the FET; for example, 1,000-2,000Angstrom is preferably used. A material which has high oxygen ion conductivity at a room temp. and generates large electromotive force in relation to oxygen partial pressure is preferable as the solid electrolyte 6. The metallic catalyst film 7 is required to be a material having the high catalyst power at a room temp.; for example, noble metals such as polatinum and palladium or laminates or alloys of some thereof are preferable. |
