An interlayer insulation film is etched to form contact holes in an
integrated circuit part. At this time, a trench is not formed in a guard
ring part. Subsequently, ion implantation is carried out in source/drain
regions in a peripheral circuit part for contact compensation, and
high-temperature annealing is carried out in order to activate implanted
impurities. Subsequently, an interlayer insulation film, a storage
capacitor, and another interlayer insulation film are formed in sequence.
Then, contact holes reaching a part of wiring layers are formed in the
peripheral circuit part while, in the guard ring part, a trench reaching
a diffusion layer is formed. Next, a barrier metal film is formed in each
of the contact holes and the trench, and further, a contact plug
comprising, for example, a W film is buried therein.