Patent ID: 8263496

Claim:
A method for forming a stepped structure on a substrate, comprising: preparing a multi-layer film stack on a substrate having alternating layers of differing composition, wherein said alternating layers of differing composition include one or more layers of a first composition and one or more layers of a second composition; preparing a mask layer on said multi-layer film stack and forming a mask pattern in said mask layer to expose a portion of said one or more layers of said first composition; and preparing a stepped structure having one or more steps using a process sequence comprising the following: transferring said mask pattern to said one or more layers of said first composition to form a first layer pattern in said one or more layers of said first composition using a first etch process and stopping on said one or more layers of said second composition, trimming said mask pattern to expose another portion of said one or more layers of said first composition using a mask trim process, and following said trimming, transferring said first layer pattern to said one or more layers of said second composition using a second etch process and stopping on said one or more layers of said first composition.