# US 8,465,655 B1 · Method of manufacturing polymer nanopillars by anodic aluminum oxide membrane and imprint process > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,465,655 B1 - Document ID: US8465655B1 - Status: Granted - Kind: B1 - Application number: 13/413,358 - Filed: 2012-03-06 - Granted: 2013-06-18 - Earliest claimed: 2012-03-06 - Assignees: University of Massachusetts - Applicants: Hongwei Sun; Sai Liu - Inventors: Hongwei Sun; Sai Liu - Web page: https://patentgrep.com/patent/US8465655B1 ## CPC - G03F 7/0002: {Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping} - B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic - B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites - B82Y 40/00: Manufacture or treatment of nanostructures - C25D 11/045: {for forming AAO templates} - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - C25D: PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR ## Abstract A fabrication method for forming polymer nanopillars using an anodic aluminum oxide (AAO) membrane and an imprint process. A substrate is cleaned and a water soluble tape is applied to the substrate to define a coating area. The substrate is spin-coated with a polymer solution and an AAO membrane is placed on top of the coated area on the substrate and turned over whereby a silicon wafer is attached onto the AAO membrane forming an AAO membrane assembly, which is pressed in an imprintor. Then, the AAO membrane assembly is removed from the imprintor, it is disassembled, and the AAO membrane is dissolved in a NaOH solution forming a polymer substrate with nanopillars. ## Claims ### Claim 1 A method for forming polymer nanopillars comprising the steps of: providing a first substrate; performing a spin-coating with a polymer solution on said first substrate; positioning an anodic aluminum oxide membrane on top of said first substrate of said coated polymer coating; turning over said first substrate with said anodic aluminum oxide membrane onto a second substrate forming an anodic aluminum oxide assembly; performing a nanoimprint process on said anodic aluminum oxide assembly with means for accurately controlling temperature and pressure; disassembling said anodic aluminum oxide assembly after said nanoimprint process; and dissolving said anodic aluminum oxide membrane in a NaOH solution leaving said polymer nanopillars formed on said first substrate. ### Claim 2 (depends on 1) The method as recited in claim 1 wherein said step of providing a first substrate includes the step of providing a quartz substrate. ### Claim 3 (depends on 1) The method as recited in claim 1 wherein said method comprises the step of cleaning said first substrate to remove any organic residue. ### Claim 4 (depends on 1) The method as recited in claim 1 wherein said step of providing a first substrate comprises the step of applying a water soluble tape over said first substrate to restrict an area of said first substrate being coated. ### Claim 5 (depends on 1) The method as recited in claim 1 wherein said method comprises the step of prebaking said spin coated first substrate at a predetermined temperature below a glass transition temperature of said polymer for removing a solvent in said polymer coating. ### Claim 6 (depends on 1) The method as recited in claim 1 wherein said method comprises the step of coating said second substrate with a release agent prior to forming said anodic aluminum oxide assembly. ### Claim 7 (depends on 1) The method as recited in claim 1 wherein said step of turning over said first substrate onto a second substrate forming an anodic aluminum oxide assembly comprises the step of providing a silicon wafer for said second substrate. ### Claim 8 (depends on 1) The method as recited in claim 1 wherein said step of performing said nanoimprint process on said anodic aluminum oxide assembly comprises the steps of: setting an imprint temperature at approximately 200° C.; setting an imprint chamber pressure at approximately 50 psia; and setting a nanoimprint time of approximately two (2) minutes. ### Claim 9 (depends on 1) The method as recited in claim 1 wherein said step of performing a spin-coating with a polymer solution comprises the step of providing said polymer solution from one of the group consisting of polymethyl methacrylate (PMMA), polyurethane (PU), polydimethylsiloxane, (PDMS) and polyacrylonitrile (PAN). ### Claim 10 A method for forming polymer nanopillars comprising the steps of: providing a first substrate, said first substrate having been cleaned to remove organic residue; applying a water soluble tape over said first substrate to restrict a coating, area; performing a spin-coating with a polymer solution onto said first substrate in said restricted coating area; prebaking said spin coated first substrate at a predetermined temperature below a glass transition temperature of said polymer coating for removing a solvent in said polymer coating; positioning an anodic aluminum oxide membrane on top of said first substrate in the area of said polymer coating; turning over said first substrate with said anodic aluminum oxide membrane onto a second substrate forming an AAO anodic aluminum oxide assembly; placing said anodic aluminum oxide assembly in a nanoimprintor at a predetermined glass transition temperature of said polymer coating and a predetermined pressure; removing said anodic aluminum oxide assembly from said nanoimprintor and disassembling said anodic aluminum oxide assembly; dissolving said anodic aluminum oxide membrane in a NaOH solution leaving said nanopillars formed on said first substrate. ### Claim 11 (depends on 10) The method as recited in claim 10 wherein said step of providing a first substrate includes the step of providing a quartz substrate. ### Claim 12 (depends on 10) The method as recited in claim 10 wherein said method comprises the step of cleaning said first substrate to remove any organic residue. ### Claim 13 (depends on 10) The method as recited in claim 10 wherein said method comprises the step of coating said second substrate with the release agent prior to forming said anodic aluminum oxide assembly. ### Claim 14 (depends on 10) The method as recited in claim 10 wherein said step of turning over said first substrate onto a second substrate forming an anodic aluminum oxide assembly comprises the step of providing a silicon wafer for said second substrate. ### Claim 15 (depends on 10) The method as recited in claim 10 wherein said step of performing said imprint process in said nanoimprintor on said anodic aluminum oxide assembly comprises the steps of: setting an imprint temperature at approximately 200° C.; setting an imprint chamber pressure at approximately 50 psia; and setting a nanoimprint time of approximately two (2) minutes. ### Claim 16 (depends on 10) The method as recited in claim 10 wherein said step of performing a spin-coating with a polymer solution comprises the step of providing said polymer solution from one of the group consisting of polymethyl methacrylate (PMMA), polyurethane (PU), polydimethylsiloxane, (PDMS) and polyacrylonitrile (PAN).