Method of forming a novel top-metal fuse structure

A method of forming a top-metal fuse structure, comprising the steps of:

• providing a substrate having an intermetal dielectric layer formed thereover;
• the substrate including a fuse region and an RDL/bump/bonding pad region;
• the substrate being comprised of a substrate selected from the group consisting of a silicon substrate, a silicon-on-oxide substrate and a GaAs substrate;
• forming a composite metal layer over the intermetal dielectric layer;
• the composite metal layer including a second metal layer sandwiched between upper and lower first metal layers;
• patterning the upper first metal layer to form an upper metal layer portion within the RDL/bump/bonding pad region;
• and
• patterning the second metal layer and the lower first metal layer:
• within the RDL/bump/bonding pad region to form an RDL/bump/bonding pad;
• the RDL/bump/bonding pad having a patterned second metal layer portion/lower first metal portion with a width greater than that of the upper metal layer portion and forming a step profile;
• and
• within the fuse region to form the top-metal fuse structure.