Semiconductor device with common contact coupling gate wiring integrated with gate electrode of antifuse to diffusion layer

Abstract

An antifuse whose internal written information cannot be analyzed even by utilizing methods to determine whether there is a charge-up in the electrodes. The antifuse includes a gate insulation film, a gate electrode, and a first diffusion layer. A second diffusion layer is isolated from the first diffusion layer by way of a device isolator film, and is the same conduction type as the first diffusion layer. The gate wiring is formed as one integrated piece with the gate electrode, and extends over the device isolator film. A common contact couples the gate wiring to the second diffusion layer. The gate electrode is comprised of semiconductor material such as polysilicon that is doped with impurities of the same conduction type as the first diffusion layer. The second diffusion layer is coupled only to the common contact.