| 摘要 |
PURPOSE:To protect a condenser which uses the first capacity unit in a semiconductor device which employs a capacitor and a field effect transistor as an information memory unit by providing the second capacity unit having an insulating layer of low insulating withstand strength. CONSTITUTION:A field effect transistor operates as source and drain at an impurity diffused layer 2 and an inversion layer 3, and constructs as a gate the second conductive layer 6 through the gate insulating film 7 of dioxidized silicon film. The first capacity unit I is formed of the layer 6 and the first conductive layer 5 through a dielectric layer 8 of dioxidized silicon film, and the second capacity unit II is formed between the second conductive layer 6 through a dioxidized silicon film 9 thinner than the region I and an inversion layer 3'. If charge is induced at the layer 5, an insulation breakdown occurs in the second unit II weaker in the insulating withstand strength, the charge of the layer 5 flows to a semiconductor substrate 1, the charge-up more than it is prevented, and the first unit I which operates as the information memory section is protected. |
