A semiconductor device comprises a multiple insulation layer structure in
which multiple insulation layers each having interconnection layer are
built up and either one of the interconnection layer forming a fuse is
blown in order to select a spare cell to relieve a defective cell; and an
opening area corresponding to said fuse, the opening being formed on one
or more insulation layers disposed above the layer which includes the
fuse, wherein a side wall position corresponding to the opening of the
first protective insulation film formed on the top layer of the multiple
layers and a side wall position corresponding to the opening of the
second protective insulation film formed on the first protective
insulation film are continuous at the boundary thereof.