| 摘要 |
PURPOSE:To obtain an ion sensor which has a long life and is hardly affected by disturbing components by forming an ion sensitive part consisting of a metallic salt, etc. forming a salt which is hardly soluble with anions to be inspected on an insulating film constituting the gate part of an FET. CONSTITUTION:The FET is constituted by forming a gate part 28, source 22 and drain 23 on a silicon substrate 21 and double coating the surface thereof with an SiO2 film 24 and an Si3N4 film 25. An Ag layer 26 which acts as a conductive layer is provided by a vacuum deposition method on the gate part 28 positioned between the source 22 and the drain 23 of the FET. The surface of the Ag layer 26 is thereafter chlorinated to form the ion sensitive part consisting of AgCl to form the FET ion sensor. The miniaturization of the sensor is thus made possible and since the ion sensitive part is constituted of the salt hardly soluble with the ions to be detected, there is no deterioration in the ion sensitivity by leak current and the sensor is less affected by the disturbing components such as protein and liquid contained in a bodily fluid such as blood or urine. The sensor having the excellent sensitivity for a long period of time is thus obtd. |
