| abstract |
A semiconductor device includes a wiring, a stack of first, second, and third films, and a contact plug. The stack of first, second, and third films is located over the wiring. The first, second, and third films are stacked in this order. The stack has an opening. The first film is made of the same material as the third film. The contact plug is in the opening. The contact plug is in contact with the wiring. |