Method for forming semiconductor device structure with conductive line

A method for forming a semiconductor device structure, comprising:

• forming a first mask layer over a dielectric layer, wherein the first mask layer has a first trench, and the first trench has a first inner wall and a bottom surface;
• forming an anti-bombardment layer over a top surface of the first mask layer and the first inner wall of the first trench, wherein the anti-bombardment layer over the top surface is thicker than the anti-bombardment layer over the first inner wall;
• forming a second mask layer over the anti-bombardment layer over the first inner wall;
• partially removing the dielectric layer through the first trench to form a second trench in the dielectric layer;
• and
• forming a conductive structure in the second trench.

A method for forming a semiconductor device structure, comprising:

• forming a first mask layer over a dielectric layer;
• forming a second mask layer over the first mask layer, wherein the second mask layer has a first trench, and the first trench has a first inner wall and a bottom surface;
• forming a third mask layer over the first inner wall, wherein the third mask layer has a second trench over a first portion of the first mask layer and a second portion of the dielectric layer;
• removing the first portion of the first mask layer, the second portion of the dielectric layer, the second mask layer, and the third mask layer to form a third trench in the dielectric layer;
• and
• forming a conductive structure in the third trench.