Patent ID: 8629058

Claim:
A method, comprising: forming a first conductor over a semiconductor substrate; forming a first dielectric layer over the first conductor; forming a second dielectric layer over the first dielectric layer; forming a via opening extending through the second dielectric layer and the first dielectric layer and extending to a top surface of the first conductor; forming a trench in the second dielectric layer that includes the via opening in the second dielectric layer and that extends over the via opening in the first dielectric layer; patterning the via opening in the first dielectric layer by removing the first dielectric layer at the upper corners of the via opening in the first dielectric layer, wherein the via opening has a tapered profile with a width of the via opening gradually increasing substantially throughout from a bottom end to a top end, wherein the corners formed at the intersection of the top of the via opening in the first dielectric material and the trench in the second dielectric layer are rounded; forming a via recess extending from the top surface of the first conductor to form a recess of a predetermined depth in the first conductor; filling the via opening with a conductor to form a via structure, and wherein the via structure includes the conductor that further extends into the via recess in the first conductor; and forming a second conductor in the trench over the first dielectric layer and adjoining the via structure at the top end.