Method for forming interconnect structure in semiconductor device

A method of fabricating a semiconductor device comprising the steps of:

• forming a first trench and a second trench having a width larger than a width of the first trench in a dielectric film overlying a semiconductor substrate after a trench pattern having a depth larger than that of the first trench is formed at a central portion of the second trench;
• depositing a conductive layer on the dielectric film including the first and the second trenches and the trench pattern;
• and
• polishing the conductive layer until a surface of the dielectric film is exposed by using a chemical-mechanical polishing to leave the conductive layer in the first and the second trenches and the trench pattern, thereby forming a damascene interconnect structure on the surface of the dielectric layer.

A method of fabricating a semiconductor device comprising the steps of:

• forming a first trench in a dielectric film overlying a semiconductor substrate and a plurality of dummy trenches having specified length, width and spacing on an open region;
• depositing a conductive layer on the dielectric film including the first trench and the dummy trenches;
• and
• polishing the conductive layer until a surface of the dielectric film is exposed by using a chemical-mechanical polishing to leave the conductive layer in the first trench and the dummy trenches, thereby forming a damascene interconnect structure on the surface of the dielectric layer.