Abstract: A method of forming damascene structures. A substrate including a dielectric layer thereon is provided. The dielectric layer has a plurality of via holes. A gap filler is formed into each via hole. Subsequently, a first anti-reflective coating (ARC) film and a second ARC film are consecutively formed on the dielectric layer. A photoresist pattern for defining a trench pattern is formed on the second ARC film. Following that, an etching process is performed to remove an upper part of the dielectric layer left uncovered by the photoresist pattern to form a plurality of trenches.

Abstract: A substrate including a dielectric layer thereon is provided. The dielectric layer has a plurality of via holes. A gap filler is formed into each via hole. Subsequently, a first anti-reflective coating (ARC) film and a second ARC film are consecutively formed on the dielectric layer. A photoresist pattern for defining a trench pattern is formed on the second ARC film. Following that, an etching process is performed to remove an upper part of the dielectric layer left uncovered by the photoresist pattern to form a plurality of trenches.