Patent ID: 8373202

Claim:
An integrated circuit chip comprising: a silicon substrate; a first analog circuit in said integrated circuit chip, wherein said first analog circuit comprises a digital-to-analog (D/A) converter; a dielectric structure over said silicon substrate; a first interconnecting structure over said silicon substrate and in said dielectric structure; a second interconnecting structure over said silicon substrate and in said dielectric structure; a first copper pad over said silicon substrate, wherein said first copper pad is connected to said first analog circuit through said first interconnecting structure; a second copper pad over said silicon substrate, wherein said second copper pad is connected to said second interconnecting structure; a separating layer over said dielectric structure, wherein said separating layer comprises a nitride layer, wherein a first opening in said separating layer is over a first contact point of said first copper pad, and said first contact point is at a bottom of said first opening, and wherein a second opening in said separating layer is over a second contact point of said second copper pad, and said second contact point is at a bottom of said second opening; and a third interconnecting structure over said separating layer and on said first and second contact points, wherein a first analog signal path is between said first analog circuit and said third interconnecting structure and passes through said first copper pad and said first interconnecting structure, wherein said first contact point is connected to said second contact point through said third interconnecting structure, wherein said third interconnecting structure is connected to said second interconnecting structure through said second copper pad, wherein said third interconnecting structure comprises a first metal layer and a second metal layer on said first metal layer, wherein said first metal layer is under said second metal layer, but is not at a sidewall of said second metal layer.