High density metal cross-point laser linking

Laser-programmed inter-level metal connections have been developed as a means of achieving high-density linking for additive redundancy in restructurable logic and in wafer scale integration. The authors report on the successful linking of 8×8 cross-points of aluminium alloy lines separated by SiN_x insulation. Both processing and linking issues are addressed. The processing issues are extensions of the problems associated with any reliable two-level metal process with the added concerns of making structures for laser linking. The linking issues involve aiming a laser and forming a link with minimum peripheral damage to either the connecting metal lines or the underlying oxide and silicon