Patent ID: 8168527

Claim:
A method of forming a semiconductor chip, comprising: providing a silicon substrate, an active device in and on said silicon substrate, a first dielectric layer over said silicon substrate, a metallization structure over said first dielectric layer, wherein said metallization structure comprises a first metal layer and a second metal layer over said first metal layer, a second dielectric layer between said first and second metal layers, and a passivation layer over said metallization structure and said first and second dielectric layers, wherein a first opening in said passivation layer is over a contact point of said metallization structure, and said contact point is at a bottom of said first opening; forming a polymer bump on a first region of a top surface of said passivation layer and over said active device, wherein said polymer bump has a thickness between 5 and 50 micrometers and a width between 5 and 60 micrometers; after said forming said polymer bump, forming an adhesion layer over said contact point, on second and third regions of said top surface of said passivation layer, and on said polymer bump, wherein said second region is between said first region and said first opening, and said first region is between said second and third regions; after said forming said adhesion layer, forming a seed layer on said adhesion layer; after said forming said seed layer, forming a photoresist layer on said seed layer, wherein a second opening in said photoresist layer exposes a fourth region of said seed layer, wherein said second opening is vertically over said contact point, vertically over said first, second and third regions, and vertically over said polymer bump; after said forming said photoresist layer, forming a third metal layer on said fourth region, vertically over said contact point, vertically over said first, second and third regions, and vertically over said polymer bump, wherein said third metal layer has a same material as that of said seed layer, wherein said third metal layer is connected to said contact point through said first opening, wherein said forming said third metal layer comprises an electroplating process; after said forming said third metal layer, removing said photoresist layer; after said removing said photoresist layer, removing said seed layer not under said third metal layer; and after said removing said seed layer not under said third metal layer, removing said adhesion layer not under said third metal layer, wherein after said removing said adhesion layer not under said third metal layer, said third metal layer has a first portion vertically over said polymer bump, a second portion vertically over said second region and a third portion vertically over said third region, wherein said third portion is connected to said second portion through said first portion, wherein said first portion is connected to said contact point through said second portion.