Method for etching a metal layer with dimensional control

摘要

A method for etching a metal layer on a substrate with dimensional control is disclosed. First, an anti-reflection layer is formed over the metal layer. A photoresist layer is then formed over the anti-reflection layer. A metal layer pattern is defined by patterning the photoresist layer. An etching process is performed to etch the anti-reflection layer with dimensional loss compared with the metal layer pattern, by using the photoresist layer as a mask. Another etching process is performed to etch the metal layer with dimensional gain compared with the anti-reflection layer, by using the anti-reflection layer as a mask. A metal layer with nearly zero-biased dimension is achieved.