Patent ID: 8304842

Claim:
An interconnection structure comprising: a first gate electrode having a first portion of a first work-function metal layer under a first portion of a signal metal layer; a second gate electrode having a second portion of the first work-function metal layer interposed between a second work-function metal layer and a second portion of the signal metal layer, wherein the second portion of the signal metal layer is over the second portion of the first work-function metal layer, wherein the second portion of the signal metal layer and the first portion of the signal metal layer are continuous, wherein a maximum thickness of the second portion of the signal metal layer is less than a maximum thickness of the first portion of the signal metal layer; a first barrier layer between the first work-function metal layer and the second work-function metal layer and extending along a sidewall of the first work-function metal layer; and a second barrier layer between the signal metal layer and the first work-function metal layer.