| 摘要 |
PURPOSE:To prevent deterioration of an FET part, by using the metallic oxide film gate FET, inserting an ion-sensitive part at the end of dielectric material connected to a gate electrode and a comparing electrode in electrolyte solution or electrolytic gel and providing a gas-permeable film on the top of the ion- sensitive part. CONSTITUTION:A long support 2 composed of insulating material is connected to a substrate 1 bearing an MOSFET3 and a wire-shaped sensor electrode 8 connected to the comparing electrode wiring 7 and gate electrode of FET3 are installed on the support 2. A silver electrode 11 for comparing electrode and the sensor electrode 8 covered with an ion-sensitive film 12 are formed in a recess at the end of the support 2 and the end part of the support 2 is covered with the gas permeable film 10 by filling the recess with inside gel 13. By disclosing the substrate 1 and the end part 20 of the support 2, the support 2 is put into a case 21 to fix with resin 24. Thus, separation of the ion-sensitive part 9 from the FET3 prevents deterioration of the FET3 and a durable gas sensor available for a small medical sensor can be obtained. |
