Minimum Groundrule, Electrically Blown Tungsten/Aluminum Fuse by Electromigration
Original Publication Date: 1988-Oct-01
Included in the Prior Art Database: 2005-Feb-15
A method is shown for integrating mixed electromigration resistance materials in VLSI semiconductor wiring, thereby promoting the practice of electrically blowing fuses utilized to engage circuit design redundancy. The utilization of a laser to blow fuses in VLSI semiconductors for the purpose of engaging redundancy has the disadvantage of minimum imaging ability of the laser's spot size. Lasers can only image efficiently through thin oxides; therefore, additional masking defined by large groundrules is required to open up terminal metals. Laser fuse blowing destroys the fuse link and explodes fragments a considerable distance away from the fuse area. To accommodate this problem, minimum distance ground rules are utilized, resulting in a circuit density impact.