| 摘要 |
PURPOSE:To arbitrarily and simply vary the capacity of a semiconductor variable capacitance element by forming a floating electrode insulated externally and covered with an insulating film on a semiconductor substrate and charging the electrode. CONSTITUTION:A floating electrode 3 insulated externally and covered with oxidized insulating film 2 is formed on a semiconductor substrate 1, and an electrode 4 capacitively coupled with the electrode 3 is formed on the electrode 3. An impurity diffused layer 6 of reverse conductive type to the substrate 1 is formed on the substrate 1, and is contacted partly of the electrode 3 via an insulating oxidized film 5. The surface of the substrate 1 can be inverted, depleted, or stored in accordance with the charging amount of the electrode 3. The capacity between the electrode 4 and the substrate 1 is varied in accordance with the inverted, depleted or stored state of the surface of the substrate 1. |
