Patent ID: 8906244

Claim:
A method of forming a device having nanopillar and cap structures on a substrate comprising the steps of: coating the substrate with a first negative electron beam resist and baking said first resist to form a first resist layer having a first exposure dose to electron beam radiation, coating the first resist layer with a second negative electron beam resist and baking said second resist to form a second resist layer having a second exposure dose to electron beam radiation which is less than said first exposure dose, performing electron beam lithography at a first level dose in the areas of the nanopillars to thereby expose the first resist layer, performing electron beam lithography at a second level dose substantially lower than the first level dose in the areas of the caps to thereby expose the second resist layer, whereby the first resist layer is substantially unaffected by the second level dose, thereafter developing both the first and second resist; wherein the nanopillar structure and the cap structure of the formed device each comprise a cross sectional width, and the cross sectional width of the cap structure is greater than the cross sectional width of the nanopillar structure.