Redundant memory device having a memory cell and electrically breakable circuit having the same dielectric film

Claim 1

A semiconductor device which comprises a dynamic random access memory (DRAM) unit and a redundancy circuit therefor, the DRAM unit being comprised of a MOS transistor and a capacitor connected to the MOS transistor, the capacitor being comprised of a dielectric film interposed between two electrodes, the dielectric film being comprised of a silicon oxide/silicon/nitride/silicon oxide composite layer, the redundancy circuit having an electrically breakable dielectric film interposed between two electrodes, the electrically breakable dielectric film being the same film as the dielectric film of a silicon/oxide/silicon nitride/silicon oxide composite layer and interposed at a connection between the DRAM unit and the redundancy circuit, whereby the application of a predetermined voltage to the two electrodes between which the breakable dielectric film is interposed breaks the breakable dielectric film and electrically connects the DRAM unit and the redundancy circuit.