Fin field effect transistor (finfet) device structure with interconnect structure

A semiconductor device structure, comprising:

• a first metal layer formed over a substrate;
• a dielectric layer formed over the first metal layer;
• an adhesion layer formed in the dielectric layer and over the first metal layer;
• and
• a second metal layer formed in the dielectric layer, wherein the adhesion layer is formed between the second metal layer and the dielectric layer, and the second metal layer comprises a via portion and a trench portion above the via portion, and wherein
• the adhesion layer comprises a first portion adjacent to the trench portion of the second metal layer, the first portion has an extending tip, and the extending tip is located at a position which is lower than a highest point of the via portion of the second metal layer.

A semiconductor device structure, comprising:

• a first metal layer formed over a substrate;
• a dielectric layer formed over the first metal layer;
• and
• a second metal layer formed in the dielectric layer, wherein the second metal layer is electrically connected to the first metal layer, the second metal layer comprises an upper portion, an middle portion and a lower portion, the middle portion is between the upper portion and the lower portion and the middle portion has a pair of curved sidewalls.