Disclosed is a semiconductor device having a precision-worked dual damascene
structure. A semiconductor substrate is obtained by forming at least a first interlayer
film, an etching stopper film, a second interlayer film, a first hard mask and
a second hard mask on a substrate in the order mentioned, the second hard mask
being formed to have a trench pattern. At least a light absorbing sacrificial film,
which has an etching rate different from that of a photoresist and is removable
by use of a stripping solution, is formed on the semiconductor substrate in such
a manner that the overall surface thereof will be flat. The photoresist is formed
on the light absorbing sacrificial film and has an aperture pattern whose opening
width is less than that of the trench pattern. At least the light absorbing sacrificial
film, the first hard mask and the second interlayer film are etched selectively,
one after the other, using the photoresist as an etching mask.
