A semiconductor device is disclosed, which includes at least two layers
superposed on each other in a stacking direction above a substrate, each
of the layers including an insulating film a conductive layer films, a
conductive plug electrically connected to the conductive layer, and at
least one dummy via chain provided in the insulating films and stacked in
the at least two layers, wherein the dummy via chain includes at least
two reinforcing metal layers and at least one reinforcing plug.