Lithography with reduced feature pitch using rotating mask techniques
AssigneeRolith, Inc.
InventorsBoris Kobrin, Mark Brongersma, Edward Barnard
Life of this patent
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Abstract
Embodiments of the present invention are directed to techniques for obtaining patterns of features. One set of techniques uses multiple-pass rolling mask lithography to obtain the desired feature pattern. Another technique uses a combination of rolling mask lithography and a self-aligned plasmonic mask lithography to obtain a desired feature pitch.
Claims19
A method for printing a pattern of features, the method comprising:
- contacting a photoresist on a substrate with a surface of a cylindrical mask having a pattern formed on the surface, transmitting radiation from inside the cylindrical mask through the pattern formed on the surface to the surface;
- rotating the cylindrical mask, while translating the substrate and maintaining contact between the mask and the photoresist in two or more passes of the substrate past the cylindrical mask to expose the photoresist to two or more corresponding patterns of features.
The method of claim 9, wherein the first and second cylindrical masks are arranged in tandem with the substrate passing both the first and second cylindrical masks in the same direction with both cylindrical masks rotating in the same corresponding sense.
A method for printing a pattern of features characterized by a given pitch and feature size, the method comprising:
- contacting a first photoresist layer on a substrate with a surface of a cylindrical mask having a pattern of features formed on the surface, transmitting radiation from inside the cylindrical mask through the pattern formed on the surface of the cylindrical mask to the first photoresist layer;
- rotating the cylindrical mask, while translating the substrate and maintaining contact between the mask and the first photoresist layer to expose the first photoresist layer to a corresponding first pattern of features, wherein the first pattern of features is characterized by the given pitch and feature size;
- developing the first photoresist layer to expose portions of the substrate to openings in the photoresist corresponding to the pattern of features;
- depositing metal through the openings onto the substrate, thereby forming a corresponding first pattern of metal features on the substrate;
- removing the first photoresist layer;
- forming a spacer layer over the substrate and the first pattern of metal features;
- forming a second photoresist layer over the spacer layer;
- illuminating the metal features through the substrate with radiation characterized by a wavelength and intensity configured to generate a pattern of plasmons within the metal features, wherein the pattern of plasmons results in portions of the second photo resist layer between the metal features being soluble;
- developing the second photoresist to form openings at the soluble portions thereby forming a second pattern of features, wherein features in the second pattern are located in spaces between features in the first pattern of metal features;
- etching portions of the spacer layer through the openings in the second photo resist layer to expose corresponding portions of the substrate;
- and
- depositing metal through the openings in the second photoresist layer to form a second pattern of metal features.
Dependencies are inferred from the claim text.