Method for forming interconnect structure

A method for forming an interconnect structure, the method comprising:

• forming a first dielectric layer on a substrate;
• forming an opening in the first dielectric layer;
• forming a first metal layer, a second metal layer, and a third metal layer sequentially over the first dielectric layer, wherein the opening of the first dielectric layer is filled with the first metal layer to form a conductive via;
• and
• performing one or more etch operation to etch the first metal layer, the second metal layer, and the third metal layer, so as to form a metal line corresponding to the first metal layer, an intermediate metal layer corresponding to the second metal layer, and a metal pillar corresponding to the third metal layer, wherein a width of the metal line is greater than a width of the metal pillar.

A method for forming an interconnect structure, the method comprising:

• providing a substrate;
• depositing a first metal layer over the substrate;
• etching the first metal layer to form a metal line;
• and
• after etching the first metal layer, depositing a dielectric layer that surrounds the metal line.