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).
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Patent number: 11054750Abstract: 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: GrantFiled: September 11, 2014Date of Patent: July 6, 2021Assignee: ASML Netherlands B.V.Inventors: Duan-Fu Stephen Hsu, Rafael C. Howell, Feng-Liang Liu
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Patent number: 11016395Abstract: A method including: obtaining a thin-mask transmission function of a patterning device and a M3D model for a lithographic process, wherein the thin-mask transmission function represents a continuous transmission mask and the M3D model at least represents a portion of M3D attributable to multiple edges of structures on the patterning device; determining a M3D mask transmission function of the patterning device by using the thin-mask transmission function and the M3D model; and determining an aerial image produced by the patterning device and the lithographic process, by using the M3D mask transmission function.Type: GrantFiled: December 6, 2017Date of Patent: May 25, 2021Assignee: ASML Netherlands B.V.Inventors: Yu Cao, Yen-Wen Lu, Peng Liu, Rafael C. Howell, Roshni Biswas
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Patent number: 10990003Abstract: A method to determine a mask pattern for a patterning device. The method includes obtaining a target pattern to be printed on a substrate, an initial continuous tone image corresponding to the target pattern, a binarization function (e.g., a sigmoid, an arctan, a step function, etc.) configured to transform the initial continuous tone image, and a process model configured to predict a pattern on the substrate from an output of the binarization function; and generating a binarized image having a mask pattern corresponding to the initial continuous tone image by iteratively updating the initial continuous tone image based on a cost function such that the cost function is reduced. The cost function (e.g., EPE) determines a difference between a predicted pattern determined by the process model and the target pattern.Type: GrantFiled: February 15, 2019Date of Patent: April 27, 2021Assignee: ASML Netherlands B.V.Inventors: Duan-Fu Stephen Hsu, Jingjing Liu, Rafael C. Howell, Xingyue Peng
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Publication number: 20210048753Abstract: A method to determine a curvilinear pattern of a patterning device that includes obtaining (i) an initial image of the patterning device corresponding to a target pattern to be printed on a substrate subjected to a patterning process, and (ii) a process model configured to predict a pattern on the substrate from the initial image, generating, by a hardware computer system, an enhanced image from the initial image, generating, by the hardware computer system, a level set image using the enhanced image, and iteratively determining, by the hardware computer system, a curvilinear pattern for the patterning device based on the level set image, the process model, and a cost function, where the cost function (e.g., EPE) determines a difference between a predicted pattern and the target pattern, where the difference is iteratively reduced.Type: ApplicationFiled: February 28, 2019Publication date: February 18, 2021Applicant: ASML NETHERLANDS B.V.Inventors: Quan ZHANG, Been-Der CHENG, Rafael C. HOWELL, Jing SU, Yi ZOU, Yen-Wen LU
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Publication number: 20200380362Abstract: Methods of training machine learning models related to a patterning process, including a method for training a machine learning model configured to predict a mask pattern. The method including obtaining (i) a process model of a patterning process configured to predict a pattern on a substrate, wherein the process model comprises one or more trained machine learning models, and (ii) a target pattern, and training the machine learning model configured to predict a mask pattern based on the process model and a cost function that determines a difference between the predicted pattern and the target pattern.Type: ApplicationFiled: February 20, 2019Publication date: December 3, 2020Applicant: ASML NETHERLANDS B.V.Inventors: Yu CAO, Ya LUO, Yen-Wen LU, Been-Der CHEN, Rafael C. HOWELL, Yi ZOU, Jing SU, Dezheng SUN
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Publication number: 20200363713Abstract: A method to determine a mask pattern for a patterning device. The method includes obtaining a target pattern to be printed on a substrate, an initial continuous tone image corresponding to the target pattern, a binarization function (e.g., a sigmoid, an arctan, a step function, etc.) configured to transform the initial continuous tone image, and a process model configured to predict a pattern on the substrate from an output of the binarization function; and generating a binarized image having a mask pattern corresponding to the initial continuous tone image by iteratively updating the initial continuous tone image based on a cost function such that the cost function is reduced. The cost function (e.g., EPE) determines a difference between a predicted pattern determined by the process model and the target pattern.Type: ApplicationFiled: February 15, 2019Publication date: November 19, 2020Applicant: ASML NETHERLANDS B.V.Inventors: Duan-Fu Stephen HSU, Jingjing LIU, Rafael C. HOWELL, Xingyue PENG
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Publication number: 20200073260Abstract: A method including: obtaining a thin-mask transmission function of a patterning device and a M3D model for a lithographic process, wherein the thin-mask transmission function represents a continuous transmission mask and the M3D model at least represents a portion of M3D attributable to multiple edges of structures on the patterning device; determining a M3D mask transmission function of the patterning device by using the thin-mask transmission function and the M3D model; and determining an aerial image produced by the patterning device and the lithographic process, by using the M3D mask transmission function.Type: ApplicationFiled: December 6, 2017Publication date: March 5, 2020Applicant: ASML NETHERLANDS B.V.Inventors: Yu CAO, Yen-Wen LU, Peng LIU, Rafael C. HOWELL
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Patent number: 10558124Abstract: 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: GrantFiled: January 25, 2019Date of Patent: February 11, 2020Assignee: ASML Netherlands B.V.Inventors: Xiaofeng Liu, Rafael C. Howell
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Publication number: 20190369498Abstract: Methods of constructing a process model for simulating a characteristic of a product of lithography from patterns produced under different processing conditions. The methods use a deviation between the variation of the simulated characteristic and the variation of the measured characteristic to adjust a parameter of the process model.Type: ApplicationFiled: January 24, 2018Publication date: December 5, 2019Applicant: ASML NETHERLANDS B.V.Inventors: Mu FENG, Mir Farrokh SHAYEGAN SALEK, Dianwen ZHU, Leiwu ZHENG, Rafael C. HOWELL, Jen-Shiang WANG
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Patent number: 10459346Abstract: 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: GrantFiled: July 16, 2018Date of Patent: October 29, 2019Assignee: ASML Netherlands B.V.Inventors: Duan-Fu Stephen Hsu, Rafael C. Howell, Xiaofeng Liu
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Patent number: 10401732Abstract: 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: GrantFiled: March 6, 2017Date of Patent: September 3, 2019Assignee: ASML Netherlands B.V.Inventors: Duan-Fu Hsu, Luoqi Chen, Hanying Feng, Rafael C. Howell, Xinjian Zhou, Yi-Fan Chen
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Publication number: 20190155165Abstract: 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: ApplicationFiled: January 25, 2019Publication date: May 23, 2019Applicant: ASML Netherlands B.V.Inventors: Xiaofeng LIU, Rafael C. Howell
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Patent number: 10191384Abstract: 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: GrantFiled: February 4, 2014Date of Patent: January 29, 2019Assignee: ASML Netherlands B.V.Inventors: Xiaofeng Liu, Rafael C. Howell
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Publication number: 20180341186Abstract: 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: ApplicationFiled: July 16, 2018Publication date: November 29, 2018Applicant: ASML Netherlands B.V.Inventors: Duan-Fu Stephen HSU, Rafael C. HOWELL, Xiaofeng LIU
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Patent number: 10025201Abstract: 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: GrantFiled: February 13, 2015Date of Patent: July 17, 2018Assignee: ASML Netherlands B.V.Inventors: Duan-Fu Stephen Hsu, Rafael C. Howell, Xiaofeng Liu
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Publication number: 20180120709Abstract: 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: ApplicationFiled: May 13, 2016Publication date: May 3, 2018Applicant: ASML Netherlands B.V.Inventors: Duan-Fu Stephen HSU, Rafael C. HOWELL, Jianjun JIA
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Publication number: 20170176864Abstract: 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: ApplicationFiled: March 6, 2017Publication date: June 22, 2017Applicant: ASML Netherlands B.V.Inventors: Duan-Fu HSU, Luoqi Chen, Hanying Feng, Rafael C. Howell, Xinjian Zhou, Yi-Fan Chen
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Patent number: 9588438Abstract: 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: GrantFiled: November 9, 2011Date of Patent: March 7, 2017Assignee: ASML NETHERLANDS B.V.Inventors: Duan-Fu Hsu, Luoqi Chen, Hanying Feng, Rafael C. Howell, Xinjian Zhou, Yi-Fan Chen
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Publication number: 20170038692Abstract: 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: ApplicationFiled: February 13, 2015Publication date: February 9, 2017Applicant: ASML Netherlands B.V.Inventors: Duan-Fu Stephen HSU, Rafael C. HOWELL, Xiaofeng LIU
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Publication number: 20160231654Abstract: 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: ApplicationFiled: September 11, 2014Publication date: August 11, 2016Applicant: ASML NETHERLANDS B.V.Inventors: Duan-Fu Stephen HSU, Rafael C. HOWELL, Feng-Liang LIU