Abstract: There is described a semiconductor device having a copper fuse which prevents damage to a silicon substrate beneath the copper fuse, which would otherwise be caused by a laser beam radiated to blow the copper fuse. A light absorbing layer is formed on the copper fuse layer from material whose light absorption coefficient is greater than that of a copper wiring layer. Light absorbed by the light absorbing layer is transmitted, through heat conduction, to the copper wiring layer beneath the light absorbing layer and further to a barrier metal layer beneath the copper wiring layer. Even when the widely-used conventional laser beam of infrared wavelength is used, the copper fuse can be blown. Since a guard layer is formed below the fuse layer, there can be prevented damage to the silicon substrate, which would otherwise be caused by exposure to the laser beam of visible wavelength.

Abstract: On a silicon substrate, silicon oxide film is formed. On the silicon oxide film, a BPSG film is formed. On the BPSG film, a silicon oxide film which does not include at least phosphorus and has a thickness equal to or more than about 1 &mgr;m is formed as a protective film. On the silicon film, a fuse is formed. Covering the fuse, a silicon oxide film which does not include at least phosphorus is formed on the silicon oxide film. Thus, the corrosion of the fuse is prevented, whereby a semiconductor device with highly reliable metal interconnection can be obtained.

Abstract: A semiconductor device includes: an insulation layer; a fuse layer extending on the insulation layer in one direction and disconnected through light radiation to control a redundant circuit; a pseudo fuse layer on the insulation layer along at least one side of the fuse layer; another insulation layer covering the fuse layer and the pseudo fuse layer; and a protection film formed on another insulation layer and having an opening in a region opposite to the fuse layer. Fuse layers having a spacing of less than 4 &mgr;m or 4.5 to 5.5 &mgr;m. Such a structure allows a semiconductor device with a fuse layer capable of being disconnected reliably and providing a smaller blow trace.