| 摘要 |
PURPOSE:To prevent the breakdown of a capacitor insulating film, by forming at least one film of a memory capacitor so that the thickness of the film is thinner than those of other films, and providing a dummy cell, which does not have interconnection wiring for constituting a memory cell array on the upper part. CONSTITUTION:In a memory capacitor, insulating films 3, which are aligned between field oxide films 2 on a silicon substrate 1, are used as dielectric. A phosphorus doped polycrystalline silicon plate 4 is used as one electrode plane. One memory capacitor insulating film 3a is selectively made thinner than those of other films. A memory cell on the insulating film 3a does not have interconnection wiring for constituting a memory cell array. The thin memory capacitor insulating film 3a becomes the discharge path of electric charge, which is stored in the polycrystalline silicon plate 4. The film 3a acts to prevent the breakdown of the other memory capacitor insulating films 3, which function as the memory cell array. |
