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US 11,960,204 B2Granted
Microlithographic fabrication of structures
AssigneeMolecular Imprints, Inc.
InventorVikramjit Singh
Life of this patent
Estimating the term…
Abstract
Asymmetric structures formed on a substrate and microlithographic methods for forming such structures. Each of the structures has a first side surface and a second side surface, opposite the first side surface. A profile of the first side surface is asymmetric with respect to a profile of the second side surface. The structures on the substrate are useful as a diffraction pattern for an optical device.
Claims18
A microlithographic method of forming asymmetric structures, the method comprising:
- forming a plurality of discrete structures extending from a common surface on a substrate;
- applying a masking material over the plurality of discrete structures under first conditions that cause the masking material to asymmetrically cover the plurality of discrete structures such that at least a portion of one side of each discrete structure of the plurality of discrete structures is free of the masking material, wherein the first conditions that cause the masking material to asymmetrically cover the plurality of discrete structures comprise inclining the substrate at a first non-normal angle to a deposition direction from which the masking material is applied by a deposition system;
- applying a metal catalyst layer for metal assisted chemical etching (MACE) over the plurality of discrete structures under second conditions that cause the metal catalyst layer to asymmetrically cover the plurality of discrete structures such that at least a second portion of one side of each discrete structure of the plurality of discrete structures is free of the metal catalyst layer, wherein the second conditions that cause the metal catalyst layer to asymmetrically cover the plurality of discrete structures comprise inclining the substrate at a second non-normal angle to the deposition direction from which the metal catalyst layer is applied by the deposition system, wherein the second non-normal angle is different from the first non-normal angle;
- etching an area of the plurality of discrete structures that is not covered by the masking material and that is covered by the metal catalyst layer;
- and
- stripping the masking material from the plurality of discrete structures.
3 more elements
An optical device comprising:
- a substrate;
- and
- a diffraction pattern on the substrate, the diffraction pattern comprising a plurality of asymmetric structures, wherein the plurality of asymmetric structures are formed by a process comprising:
- forming a plurality of discrete structures extending from a common surface on the substrate;
- applying a masking material over the plurality of discrete structures under first conditions that cause the masking material to asymmetrically cover the plurality of discrete structures such that at least a portion of one side of each discrete structure of the plurality of discrete structures is free of the masking material, wherein the first conditions that cause the masking material to asymmetrically cover the discrete structures comprise inclining the substrate at a first non-normal angle to a deposition direction from which the masking material is applied by a deposition system;
- applying a metal catalyst layer for metal assisted chemical etching (MACE) over the plurality of discrete structures under second conditions that cause the metal catalyst layer to asymmetrically cover the plurality of discrete structures such that at least a second portion of one side of each discrete structure of the plurality of discrete structures is free of the metal catalyst layer, wherein the second conditions that cause the metal catalyst layer to asymmetrically cover the plurality of discrete structures comprise inclining the substrate at a second non-normal angle to the deposition direction from which the metal catalyst layer is applied by the deposition system, wherein the second non-normal angle is different from the first non-normal angle;
- etching an area of the plurality of discrete structures that is not covered by the masking material and that is covered by the metal catalyst layer;
- and
- stripping the masking material from the plurality of discrete structures.
6 more elements
Dependencies are inferred from the claim text.