PURPOSE: To prevent effects detrimental to device characteristics by a method wherein an anti-laser shield is provided beforehand between a fuse and a substrate when a polycrystalline Si fuse provided on a substrate is subjected to a laser beam for fusing, in a semiconductor memory wherein a redundancy circuit needs to be electrically activated or faulty parts need to be deactivated.

CONSTITUTION: A p+ type field doped layer 11, a field oxide film 20, and then a layer 23 of polycrystalline Si or a high melt point metal exemplifiedly Mo are laid down on an Si substrate 10. On the lamination, a fuse forming polycrysralline Si layer 30 is formed with a part of its periphery surrrounded with an oxide film 21. Next, a coating of an oxide film 21 is further added, the fuse layer 30 exposed in the periphery thereof provided with a metal wiring 40 across a contact layer 45 for the formation of memory. A laser beam 60 is applied as necessary through the film 21 for the fusing of the layer 30 into a prescribed pattern. Before laser application, a shield 32 composed of polycrystalline Si is provided between the layers 20 and 23 to stop the laser beam 60.