Patents by Inventor Weijun Liu

Weijun Liu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20170285463
    Abstract: A pattern is formed on a substrate with forming a layer of a curable composition (A1) containing a component (a1) serving as a polymerizable compound (a1) and a component (b1) serving as a photopolymerization initiator on a surface of the substrate, then dispensing droplets of a curable composition (A2) containing a component (a2) serving as a polymerizable compound (a2) and a component (b2) serving as a photopolymerization initiator dropwise discretely onto the layer of the curable composition (A1), subsequently sandwiching a mixture layer of the curable composition (A1) and the curable composition (A2) between a mold and the substrate, then irradiating the mixture layer with light to cure the mixture layer, and releasing the mold from the mixture layer after the curing.
    Type: Application
    Filed: March 8, 2017
    Publication date: October 5, 2017
    Inventors: Toshiki Ito, Weijun Liu, Timothy Brian Stachowiak, Niyaz Khusnatdinov, Tomonori Otani, Masayuki Tanabe
  • Publication number: 20170285479
    Abstract: A nanoimprint lithography method includes disposing a pretreatment composition on a nanoimprint lithography substrate to form a pretreatment coating, and disposing discrete portions of imprint resist on the pretreatment coating, each discrete portion of the imprint resist covering a target area of the nanoimprint lithography substrate. The imprint resist is a polymerizable composition and includes a polymerization initiator. A composite polymerizable coating is formed on the nanoimprint lithography substrate as each discrete portion of the imprint resist spreads beyond its target area. The composite polymerizable coating is contacted with a nanoimprint lithography template. The polymerization initiator is activated, and the composite polymerizable coating is polymerized to yield a composite polymeric layer and an uncured portion of the pretreatment coating on the nanoimprint lithography substrate.
    Type: Application
    Filed: March 24, 2017
    Publication date: October 5, 2017
    Inventors: Timothy Brian Stachowiak, Weijun Liu
  • Patent number: 9778562
    Abstract: An imprint lithography template or imprinting stack includes a porous material defining a multiplicity of pores with an average pore size of at least about 0.4 nm. A porosity of the porous material is at least about 10%. The porous template, the porous imprinting stack, or both may be used in an imprint lithography process to facilitate diffusion of gas trapped between the template and the imprinting stack into the template, the imprinting stack or both, such that polymerizable material between the imprinting stack and the template rapidly forms a substantially continuous layer between the imprinting stack and the template.
    Type: Grant
    Filed: November 21, 2008
    Date of Patent: October 3, 2017
    Assignee: Canon Nanotechnologies, Inc.
    Inventors: Frank Y. Xu, Weijun Liu, Edward Brian Fletcher, Sidlgata V. Sreenivasan, Byung Jin Choi, Niyaz Khusnatdinov, Anshuman Cherala, Kosta S. Selinidis
  • Patent number: 9651862
    Abstract: Imprint lithography methods that incorporate depositing droplets of polymerizable material in patterns that improve fill time performance when employing directionally-oriented imprint templates. The patterns are based on grid arrays formed of repeating sets of rows of droplets oriented along fast and slow axes, with droplets of each row offset along the slow axis relative to droplets in adjacent rows.
    Type: Grant
    Filed: July 11, 2014
    Date of Patent: May 16, 2017
    Assignee: Canon Nanotechnologies, Inc.
    Inventors: Edward Brian Fletcher, Gerard M. Schmid, Se-Hyuk Im, Niyaz Khusnatdinov, Yeshwanth Srinivasan, Weijun Liu, Frank Y. Xu
  • Publication number: 20170068159
    Abstract: A nanoimprint lithography method includes disposing a pretreatment composition on a substrate to form a pretreatment coating. The pretreatment composition includes a polymerizable component. Discrete imprint resist portions are disposed on the pretreatment coating, with each discrete portion of the imprint resist covering a target area of the substrate. A composite polymerizable coating is formed on the substrate as each discrete portion of the imprint resist spreads beyond its target area. The composite polymerizable coating includes a mixture of the pretreatment composition and the imprint resist. The composite polymerizable coating is contacted with a template, and is polymerized to yield a composite polymeric layer on the substrate. The interfacial surface energy between the pretreatment composition and air exceeds the interfacial surface energy between the imprint resist and air or between at least a component of the imprint resist and air.
    Type: Application
    Filed: January 22, 2016
    Publication date: March 9, 2017
    Inventors: Niyaz Khusnatdinov, Timothy Brian Stachowiak, Weijun Liu
  • Publication number: 20170066208
    Abstract: A nanoimprint lithography method includes disposing a pretreatment composition on a substrate to form a pretreatment coating. The pretreatment composition includes a polymerizable component. Discrete imprint resist portions are disposed on the pretreatment coating, with each discrete portion of the imprint resist covering a target area of the substrate. A composite polymerizable coating is formed on the substrate as each discrete portion of the imprint resist spreads beyond its target area. The composite polymerizable coating includes a mixture of the pretreatment composition and the imprint resist. The composite polymerizable coating is contacted with a template, and is polymerized to yield a composite polymeric layer on the substrate. The interfacial surface energy between the pretreatment composition-and air exceeds the interfacial surface energy between the imprint resist and air or between at least a component of the imprint resist and air.
    Type: Application
    Filed: June 28, 2016
    Publication date: March 9, 2017
    Inventors: Niyaz Khusnatdinov, Timothy Brian Stachowiak, Weijun Liu
  • Publication number: 20170068161
    Abstract: A nanoimprint lithography method includes contacting a composite polymerizable coating formed from a pretreatment composition and an imprint resist with a nanoimprint lithography template defining recesses. The composite polymerizable coating is polymerized to yield a composite polymeric layer defining a pre-etch plurality of protrusions corresponding to the recesses of the nanoimprint lithography template. The nanoimprint lithography template is separated from the composite polymeric layer. At least one of the pre-etch plurality of protrusions corresponds to a boundary between two of the discrete portions of the imprint resist, and the pre-etch plurality of protrusions have a variation in pre-etch height of ±10% of a pre-etch average height. The pre-etch plurality of protrusions is etched to yield a post-etch plurality of protrusions having a variation in post-etch height of ±10% of a post-etch average height, and the pre-etch average height exceeds the post-etch average height.
    Type: Application
    Filed: September 8, 2016
    Publication date: March 9, 2017
    Inventors: Timothy Stachowiak, Weijun Liu, Fen Wan, Gary Doyle
  • Patent number: 9323143
    Abstract: A nano-imprint lithography process includes forming a multiplicity of hydroxyl groups on a surface of a substantially inorganic nano-imprint lithography template, heating the template, and reacting a pre-selected percentage of the hydroxyl groups on the surface of the template with a mono-functional, non-fluorinated compound to form a monolayer coating on the surface of the nano-imprint lithography template. The coated template may be contacted with a polymerizable composition disposed on a nano-imprint lithography substrate, and the polymerizable composition solidified to form a patterned layer. The coated template is separated from the patterned layer.
    Type: Grant
    Filed: February 3, 2009
    Date of Patent: April 26, 2016
    Assignees: Canon Nanotechnologies, Inc., Molecular Imprints, Inc.
    Inventors: Frank Y. Xu, Weijun Liu
  • Patent number: 9063409
    Abstract: Porous nano-imprint lithography templates may include pores, channels, or porous layers arranged to allow evacuation of gas trapped between a nano-imprint lithography template and substrate. The pores or channels may be formed by etch or other processes. Gaskets may be formed on an nano-imprint lithography template to restrict flow of polymerizable material during nano-imprint lithography processes.
    Type: Grant
    Filed: June 5, 2013
    Date of Patent: June 23, 2015
    Assignees: Canon Nanotechnologies, Inc., Molecular Imprints, Inc.
    Inventors: Niyaz Khusnatdinov, Weijun Liu, Frank Y. Xu, Edward Brian Fletcher, Fen Wan
  • Publication number: 20150017329
    Abstract: Imprint lithography methods that incorporate depositing droplets of polymerizable material in patterns that improve fill time performance when employing directionally-oriented imprint templates. The patterns are based on grid arrays formed of repeating sets of rows of droplets oriented along fast and slow axes, with droplets of each row offset along the slow axis relative to droplets in adjacent rows.
    Type: Application
    Filed: July 11, 2014
    Publication date: January 15, 2015
    Applicants: Toshiba Corporation, Canon Nanotechnologies, Inc.
    Inventors: Edward Brian Fletcher, Gerard M. Schmid, Se-Hyuk Im, Niyaz Khusnatdinov, Yeshwanth Srinivasan, Weijun Liu, Frank Y. Xu
  • Publication number: 20140212534
    Abstract: An imprint lithography template includes a porous material defining a multiplicity of pores with an average pore size of at least about 0.4 nm. The porous material includes silicon and oxygen, and a ratio of Young's modulus (E) to relative density of the porous material with respect to fused silica (?porous/?fused silica) is at least about 10:1. A refractive index of the porous material is between about 1.4 and 1.5. The porous material may form an intermediate layer or a cap layer of an imprint lithography template. The template may include a pore seal layer between a porous layer and a cap layer, or a pore seal layer on top of a cap layer.
    Type: Application
    Filed: January 30, 2013
    Publication date: July 31, 2014
    Applicant: MOLECULAR IMPRINTS, INC.
    Inventors: Edward B. Fletcher, Frank Y. Xu, Weijun Liu, Fen Wan, Marlon Menezes, Kosta S. Selinidis
  • Patent number: 8637587
    Abstract: Release agents with increased affinity toward nano-imprint lithography template surfaces interact strongly with the template during separation of the template from the solidified resist in a nano-imprint lithography process. The strong interaction between the surfactant and the template surface reduces the amount of surfactant pulled off the template surface during separation of a patterned layer from the template in an imprint lithography cycle. Maintaining more surfactant associated with the surface of the template after the separation of the patterned layer from the template may reduce the amount of surfactant needed in a liquid resist to achieve suitable release of the solidified resist from the template during an imprint lithography process. Strong association of the release agent with the surface of the template facilitates the formation of ultra-thin residual layers and dense fine features in nano-imprint lithography.
    Type: Grant
    Filed: September 7, 2011
    Date of Patent: January 28, 2014
    Assignee: Molecular Imprints, Inc.
    Inventors: Frank Y. Xu, Weijun Liu
  • Publication number: 20130266682
    Abstract: Porous nano-imprint lithography templates may include pores, channels, or porous layers arranged to allow evacuation of gas trapped between a nano-imprint lithography template and substrate. The pores or channels may be formed by etch or other processes. Gaskets may be formed on an nano-imprint lithography template to restrict flow of polymerizable material during nano-imprint lithography processes.
    Type: Application
    Filed: June 5, 2013
    Publication date: October 10, 2013
    Inventors: Niyaz Khusnatdinov, Weijun Liu, Frank Y. Xu, Edward Brian Fletcher, Fen Wan
  • Patent number: 8415010
    Abstract: A nano-imprint lithography stack includes a nano-imprint lithography substrate, a non-silicon-containing layer solidified from a first polymerizable, non-silicon-containing composition, and a silicon-containing layer solidified from a polymerizable silicon-containing composition adhered to a surface of the non-silicon-containing layer. The non-silicon-containing layer is adhered directly or through one or more intervening layers to the nano-imprint lithography substrate. The silicon-containing layer includes a silsesquioxane with a general formula (R?(4-2z)SiOz)x(HOSiO1.5)y, wherein R? is a hydrocarbon group or two or more different hydrocarbon groups other than methyl, 1<z<2, and x and y are integers.
    Type: Grant
    Filed: October 19, 2009
    Date of Patent: April 9, 2013
    Assignee: Molecular Imprints, Inc.
    Inventors: Weijun Liu, Frank Y. Xu
  • Publication number: 20120288686
    Abstract: A multi-layer stack for imprint lithography is formed by applying a first polymerizable composition to a substrate, polymerizing the first polymerizable composition to form a first polymerized layer, applying a second polymerizable composition to the first polymerized layer, and polymerizing the second polymerizable composition to form a second polymerized layer on the first polymerized layer. The first polymerizable composition includes a polymerizable component with a glass transition temperature less than about 25° C., and the first polymerized layer is substantially impermeable to the second polymerizable composition.
    Type: Application
    Filed: July 11, 2012
    Publication date: November 15, 2012
    Applicant: MOLECULAR IMPRINTS, INC.
    Inventors: Frank Y. Xu, Weijun Liu, Cynthia B. Brooks, Dwayne L. LaBrake, David J. Lentz
  • Patent number: 8142702
    Abstract: A solid layer is formed by applying a multiplicity of discrete portions of a fluid composition onto a surface of an imprint lithography substrate, and allowing the discrete portions of the composition to spontaneously spread on the surface of the substrate to form a substantially continuous layer. The composition includes a solvent and a solid or a solvent and a polymerizable material. The composition can be a solution or a dispersion. At least some of the solvent is evaporated from the composition, and a solid layer is formed (e.g., polymerized or dried) on the substrate. The solid layer is substantially free of interstitial voids.
    Type: Grant
    Filed: June 16, 2008
    Date of Patent: March 27, 2012
    Assignee: Molecular Imprints, Inc.
    Inventors: Weijun Liu, Frank Y. Xu, Edward Brian Fletcher
  • Publication number: 20110319516
    Abstract: Release agents with increased affinity toward nano-imprint lithography template surfaces interact strongly with the template during separation of the template from the solidified resist in a nano-imprint lithography process. The strong interaction between the surfactant and the template surface reduces the amount of surfactant pulled off the template surface during separation of a patterned layer from the template in an imprint lithography cycle. Maintaining more surfactant associated with the surface of the template after the separation of the patterned layer from the template may reduce the amount of surfactant needed in a liquid resist to achieve suitable release of the solidified resist from the template during an imprint lithography process. Strong association of the release agent with the surface of the template facilitates the formation of ultra-thin residual layers and dense fine features in nano-imprint lithography.
    Type: Application
    Filed: September 7, 2011
    Publication date: December 29, 2011
    Applicant: MOLECULAR IMPRINTS, INC.
    Inventors: Frank Y. Xu, Weijun Liu
  • Publication number: 20110189329
    Abstract: An ultra-compliant nanoimprint lithography template having a backing layer and a nanopatterned layer adhered to the backing layer. The nanopatterned layer includes nanoscale features formed by solidifying a polymerizable material in contact with a mold. The polymerizable material includes a fluoroelastomer and a photoinitiator. The backing layer has a higher elastic modulus than the nanopatterned layer. The ultra-compliant nanoimprint lithography template can be used to form multiple high fidelity imprints.
    Type: Application
    Filed: January 31, 2011
    Publication date: August 4, 2011
    Applicant: MOLECULAR IMPRINTS, INC.
    Inventors: Michael N. Miller, Weijun Liu, Frank Y. Xu
  • Publication number: 20110180127
    Abstract: Fabricating a solar cell stack includes forming a nanopatterned polymeric layer on a first surface of a silicon wafer and etching the first surface of the silicon wafer to transfer a pattern of the nanopatterned polymeric layer to the first surface of the silicon wafer. A layer of reflective electrode material is formed on a second surface of the silicon wafer. The nanopatterned first surface of the silicon wafer undergoes a buffered oxide etching. After the buffered oxide etching, the nanopatterned first surface of the silicon wafer is treated to decrease a contact angle of water on the nanopatterned first surface. Electron donor material is deposited on the nanopatterned first surface of the silicon wafer to form an electron donor layer, and a transparent electrode material is deposited on the electron donor layer to form a transparent electrode layer on the electron donor layer.
    Type: Application
    Filed: January 28, 2011
    Publication date: July 28, 2011
    Applicant: MOLECULAR IMPRINTS, INC.
    Inventors: Fen Wan, Shuqiang Yang, Frank Y. Xu, Weijun Liu, Edward Brian Fletcher, Sidlgata V. Sreenivasan, Michael N. Miller, Darren D. Donaldson
  • Publication number: 20100109201
    Abstract: A nano-imprint lithography template includes a non-porous base layer, a cap layer, and a porous layer between the base layer and the cap layer. The porous layer defines a multiplicity of pores and has an ordered pore structure. The cap layer is permeable to helium, and the pores in the porous layer are configured to accept gas passing through the cap layer during an imprint lithography process. The porous layer provides high porosity with a Young's modulus and hardness that are advantageous for imprint lithography processes.
    Type: Application
    Filed: October 30, 2009
    Publication date: May 6, 2010
    Applicant: MOLECULAR IMPRINTS, INC.
    Inventors: Edward Brian Fletcher, Frank Y. Xu, Weijun Liu, Marlon Menezes