Patents by Inventor Rafael C. Howell

Rafael C. Howell 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: 20180120709
    Abstract: A method including: determining a first simulated partial image formed, by a lithographic projection apparatus, from a first radiation portion propagating along a first group of one or more directions; determining a second simulated partial image formed, by the lithographic projection apparatus, from a second radiation portion propagating along a second group of one or more directions; and determining an image by incoherently adding the first partial image and the second partial image, wherein the first group of one or more directions and the second group of one or more directions are different.
    Type: Application
    Filed: May 13, 2016
    Publication date: May 3, 2018
    Applicant: ASML Netherlands B.V.
    Inventors: Duan-Fu Stephen HSU, Rafael C. HOWELL, Jianjun JIA
  • Publication number: 20170176864
    Abstract: Embodiments of the present invention provide methods for optimizing a lithographic projection apparatus including optimizing projection optics therein. The current embodiments include several flows including optimizing a source, a mask, and the projection optics and various sequential and iterative optimization steps combining any of the projection optics, mask and source. The projection optics is sometimes broadly referred to as “lens”, and therefore the optimization process may be termed source mask lens optimization (SMLO). SMLO may be desirable over existing source mask optimization process (SMO) or other optimization processes that do not include projection optics optimization, partially because including the projection optics in the optimization may lead to a larger process window by introducing a plurality of adjustable characteristics of the projection optics.
    Type: Application
    Filed: March 6, 2017
    Publication date: June 22, 2017
    Applicant: ASML Netherlands B.V.
    Inventors: Duan-Fu HSU, Luoqi Chen, Hanying Feng, Rafael C. Howell, Xinjian Zhou, Yi-Fan Chen
  • Patent number: 9588438
    Abstract: Embodiments of the present invention provide methods for optimizing a lithographic projection apparatus including optimizing projection optics therein. The current embodiments include several flows including optimizing a source, a mask, and the projection optics and various sequential and iterative optimization steps combining any of the projection optics, mask and source. The projection optics is sometimes broadly referred to as “lens”, and therefore the optimization process may be termed source mask lens optimization (SMLO). SMLO may be desirable over existing source mask optimization process (SMO) or other optimization processes that do not include projection optics optimization, partially because including the projection optics in the optimization may lead to a larger process window by introducing a plurality of adjustable characteristics of the projection optics.
    Type: Grant
    Filed: November 9, 2011
    Date of Patent: March 7, 2017
    Assignee: ASML NETHERLANDS B.V.
    Inventors: Duan-Fu Hsu, Luoqi Chen, Hanying Feng, Rafael C. Howell, Xinjian Zhou, Yi-Fan Chen
  • Publication number: 20170038692
    Abstract: A method to improve a lithographic process for imaging a portion of a design layout onto a substrate using a lithographic projection apparatus having an illumination system and projection optics, the method including: obtaining an illumination source shape and a mask defocus value; optimizing a dose of the lithographic process; and optimizing the portion of the design layout for each of a plurality of slit positions of the illumination source.
    Type: Application
    Filed: February 13, 2015
    Publication date: February 9, 2017
    Applicant: ASML Netherlands B.V.
    Inventors: Duan-Fu Stephen HSU, Rafael C. HOWELL, Xiaofeng LIU
  • Publication number: 20160231654
    Abstract: A method to improve a lithographic process for imaging a portion of a design layout onto a substrate using a lithographic projection apparatus having an illuminator and projection optics, the method including: computing a multi-variable cost function of a plurality of design variables that are characteristics of the lithographic process, at least some of the design variables being characteristics of the illumination produced by the illuminator and of the design layout, wherein the multi-variable cost function is a function of a three-dimensional resist profile on the substrate, or a three-dimensional radiation field projected from the projection optics, or both; and reconfiguring one or more characteristics of the lithographic process by adjusting the design variables until a predefined termination condition is satisfied.
    Type: Application
    Filed: September 11, 2014
    Publication date: August 11, 2016
    Applicant: ASML NETHERLANDS B.V.
    Inventors: Duan-Fu Stephen HSU, Rafael C. HOWELL, Feng-Liang LIU
  • Publication number: 20150378262
    Abstract: A method for improving a lithographic process for imaging a portion of a design layout onto a substrate using a lithographic projection apparatus, the method including: calculating a discrete pupil profile based on a desired pupil profile; selecting a discrete change to the discrete pupil profile; and applying the selected discrete change to the discrete pupil profile. The methods according to various embodiments disclosed herein may reduce the computational cost of discrete optimization from O(an) to O(n) wherein a is constant and n is the number of knobs that can generate discrete change in the pupil profile.
    Type: Application
    Filed: February 4, 2014
    Publication date: December 31, 2015
    Inventors: Xiaofeng LIU, Rafael C. HOWELL
  • Patent number: 8898599
    Abstract: Described herein is a method for a lithographic process for imaging a portion of a design layout onto a substrate using a lithographic imaging apparatus, the lithographic process having a plurality of design variables, the method comprising: calculating a gradient of each of a plurality of evaluation points or patterns of the lithographic process, with respect to at least one of the design variables; and selecting a subset of evaluation points from the plurality of evaluation points or patterns based on the gradient.
    Type: Grant
    Filed: May 29, 2013
    Date of Patent: November 25, 2014
    Assignee: ASML Netherlands B.V.
    Inventors: Xiaofeng Liu, Rafael C. Howell
  • Publication number: 20130326437
    Abstract: Described herein is a method for a lithographic process for imaging a portion of a design layout onto a substrate using a lithographic imaging apparatus, the lithographic process having a plurality of design variables, the method comprising: calculating a gradient of each of a plurality of evaluation points or patterns of the lithographic process, with respect to at least one of the design variables; and selecting a subset of evaluation points from the plurality of evaluation points or patterns based on the gradient.
    Type: Application
    Filed: May 29, 2013
    Publication date: December 5, 2013
    Applicant: ASML NETHERLANDS B.V.
    Inventors: Xiaofeng LIU, Rafael C. Howell
  • Publication number: 20120113404
    Abstract: Embodiments of the present invention provide methods for optimizing a lithographic projection apparatus including optimizing projection optics therein. The current embodiments include several flows including optimizing a source, a mask, and the projection optics and various sequential and iterative optimization steps combining any of the projection optics, mask and source. The projection optics is sometimes broadly referred to as “lens”, and therefore the optimization process may be termed source mask lens optimization (SMLO). SMLO may be desirable over existing source mask optimization process (SMO) or other optimization processes that do not include projection optics optimization, partially because including the projection optics in the optimization may lead to a larger process window by introducing a plurality of adjustable characteristics of the projection optics.
    Type: Application
    Filed: November 9, 2011
    Publication date: May 10, 2012
    Applicant: ASML Netherlands B.V.
    Inventors: Duan-Fu Hsu, Luoqi Chen, Hanying Feng, Rafael C. Howell, Xinjian Zhou, Yi-Fan Chen