Semiconductor device and method for forming the same

A semiconductor device, comprising:

• a first dielectric layer over a substrate and a conductive feature;
• a doped dielectric layer over the first dielectric layer;
• a second dielectric layer over the doped dielectric layer;
• and
• a first metal structure in the first dielectric layer, the doped dielectric layer, and the second dielectric layer, wherein the first metal structure comprises:
• a first metal portion in the first dielectric layer;
• a doped metal portion over the first metal portion, wherein the first metal portion and the doped metal portion comprise a same metal material, the doped dielectric layer and the doped metal portion comprise same dopants;
• and
• a second metal portion over the doped metal portion, wherein the second metal portion is a same material as the first metal portion.

A semiconductor device, comprising:

• a first dielectric layer over a substrate and a conductive feature;
• a doped dielectric layer in the first dielectric layer, at least a portion of the first dielectric layer over the doped dielectric layer being undoped;
• a first metal structure in the first dielectric layer and the doped dielectric layer, wherein the first metal structure comprises:
• a first metal portion in the first dielectric layer;
• and
• a doped metal portion over the first metal portion and in the doped dielectric layer, wherein the first metal portion and the doped metal portion comprise a same metal material, the doped dielectric layer and the doped metal portion comprise same dopants;
• and
• a second dielectric layer over the doped dielectric layer;
• and
• a second metal structure in the second dielectric layer, wherein the second metal structure contacts the first metal structure.