Method of forming dual damascene structure

Abstract

A method of forming a dual damascene structure. A first dielectric layer and a second dielectric layer are sequentially formed over a substrate. A first photoresist layer is formed over the second dielectric layer. Photolithographic and etching operations are conducted to remove a portion of the second dielectric layer and the first dielectric layer so that a via opening is formed. A conformal third dielectric layer is coated over the surface of the second dielectric layer and the interior surface of the via opening. The conformal third dielectric layer forms a liner dielectric layer. A second photoresist layer is formed over the second dielectric layer and then the second photoresist layer is patterned. Using the patterned second photoresist layer as a mask, a portion of the second dielectric layer is removed to form a trench. The patterned second photoresist layer is removed. Conductive material is deposited over the substrate to fill the via opening and the trench. Finally, chemical-mechanical polishing is conducted to remove excess conductive material above the second dielectric layer.

Dependencies are inferred from the claim text.