| 摘要 |
A damascene method of forming a C4 element includes forming a last level metal layer on a substrate, forming a TV ILD layer on the last level metal layer, forming a lithographically patterned UBM adhesion layer including one of Ti, TiW, Cr and Cu, forming a mandrel layer over the UBM adhesion layer, lithographically patterning the mandrel layer to form an aperture, depositing a solder layer by one of sputtering, evaporation, physical vapor deposition, solder wave or injection molding in the aperture, planarizing the solder layer by CMP, removing the mandrel layer, reflowing the solder to ball the solder to form a ball interconnect, and joining a second substrate with an I/O pad to the ball interconnect. |
