Alignment mark strategy for oxide CMP

摘要

A method for generating alignment marks on the scribe lines in which alignment marks are generated only at oxide layers is described. An alignment mark is formed in an oxide layer on a scribe line of a wafer. The alignment mark is lined with a metal layer and filled with a dielectric layer which is planarized. The alignment mark is used in aligning a reticle to pattern the metal layer and is also used in aligning a reticle to pattern the dielectric layer wherein the step of lining the alignment mark with the metal layer protects the alignment mark.