Patent ID: 8211791
Filing Date: 2012-07-03
Classification: H01L

Abstract:
1. A method for fabricating a chip, comprising: providing a wafer with a silicon substrate, a transistor on said silicon substrate, a first metal layer over said silicon substrate, a second metal layer over said silicon substrate and said first metal layer, a dielectric layer between said first and second metal layers, and a separating layer over said silicon substrate, said first and second metal layers and said dielectric layer, wherein a first opening in said separating layer is over a contact point of said second metal layer, and said contact point is at a bottom of said first opening; forming a first polymer layer on said separating layer, wherein a second opening passes vertically through said first polymer layer and is vertically over said contact point, said first opening and a first region of a top surface of said separating layer; forming a second polymer layer on said first polymer layer, wherein a third opening passes vertically through said second polymer layer and is vertically over said contact point, said first and second openings, said first region and a second region of a top surface of said first polymer layer; forming a third metal layer in said first, second and third openings, on a sidewall of said first opening, on a sidewall of said second opening, on a sidewall of said third opening, on a top surface of said second polymer layer, on said first and second regions, and over said separating layer; forming a fourth metal layer in said second and third openings, and over said top surface of said second polymer layer, said first and second regions, said third metal layer, and said separating layer using a process comprising an electroplating process; after said forming said fourth metal layer, removing said third and fourth metal layers over said top surface of said second polymer layer using a process comprising a polishing process; and forming a third polymer layer on said fourth metal layer, on said second polymer layer, and over said separating layer.