Stitching design rules for forming interconnect layers

Abstract

A method for stitching a plurality of mask regions including the steps of (1) defining cut regions on the mask regions, wherein the cut regions adjoin the edges of the mask regions to be stitched, (2) implementing a first set of design rules in the cut regions, and (3) implementing a second set of design rules outside of the cut regions. The mask regions can be formed on a single reticle or on a plurality of separate reticles. In one embodiment, the first set of design rules specifies that trace patterns in the cut regions have widths greater than trace patterns outside of the cut regions. In another embodiment, the first set of design rules specifies that trace patterns in the cut regions have a minimum spacing greater than trace patterns outside of the cut regions. In yet another embodiment, the first set of design rules specifies that trace patterns can be formed entirely within the cut regions. The stitching method can also include the steps of (1) defining a cut line on a wafer, (2) aligning first and second mask regions with the cut line such that transparent regions of the first and second mask regions have a controlled amount of overlap with respect to the cut line, and (3) selecting the controlled amount of overlap such that a pattern formed by the first and second mask regions has a uniform width adjacent to the cut line.