Patent ID: 7563546
Filing Date: 2009-07-21
Classification: G03F

Abstract:
1. A method of forming a phase shift mask, said method comprising: forming an opaque layer on a transparent substrate; performing a first patterning of said opaque layer to expose a first region of said transparent substrate, wherein said first region comprises an uninterrupted rectangular shape: etching said first region of said transparent substrate to create a phase shift region comprising an uninterrupted rectangular surface within said transparent substrate; and performing additional patterning of said opaque layer to expose a second region of said transparent substrate, wherein said additional patterning includes said second region and first region, said additional patterning with one side of said first region, and said additional patterning exposes an uninterrupted rectangular shape in said second region on said opaque layer immediately adjacent and substantially similar in shape and size to said first region, and removing said opaque layer within said second region to create an uninterrupted rectangular surface on said transparent substrate, wherein said process enlarges an opening in said opaque layer formed in said first patterning process.