Cutting of conductors on VLSI chips — A comparison between laser and focused ion beam removal

Abstract A comparison was made between laser evaporation-explosion and focused ion beam (FIB) sputter etching for cutting of conductors on VLSI chips. In laser cutting, thin film layers underlying the conductors and the neighboring area are liable to be damaged because of its evaporation-explosion mechanism. FIB etching has not only a submicron focusing ability but also little material dependence in its etching characteristics. Therefore, FIB cutting is more advantageous for applications to fine pattern and multilayer conductor systems in VLSIs. Under these considerations, FIB conductor cutting was successfully carried out for VLSI circuits debugging, and the effectiveness and usefulness of FIB cutting were demonstrated.