Source and mask optimization by changing intensity and shape of the illumination source and magnitude and phase of mask diffraction orders
First Claim
1. A method for obtaining a lithographic process for creating an image of a pattern at an image plane using a patterning device, the method comprising:
- by a hardware computer system,based on intensities determined for the subset of diffraction orders, selecting one or more illumination points in an illumination system and determining a transmission mask for the pattern, for which minimum image log slope is maximized in the image at each of a plurality of points, wherein determining the transmission mask comprises determining mask diffraction orders, and determining mask diffraction orders comprises performing a non-linear optimization to find optimal diffraction orders, andperforming a linear optimization by selecting quantized mask transmission to match the optimal diffraction orders,where the (a) illumination points, (b) the transmission mask, and/or (c) information derived from (a) and/or (b), is configured to design, control and/or modify the physical lithographic process involving the pattern and/or design, control and/or modify a physical object or apparatus to be used in the physical lithographic process.
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Accused Products
Abstract
An illumination source is optimized by changing the intensity and shape of the illumination source to form an image in the image plane that maximizes the minimum ILS at user selected fragmentation points while forcing the intensity at the fragmentation points to be within a small intensity range. An optimum mask may be determined by changing the magnitude and phase of the diffraction orders to form an image in the image plane that maximizes the minimum ILS at user selected fragmentation points while forcing the intensity at the fragmentation points to be within a small intensity range. Primitive rectangles having a size set to a minimum feature size of a mask maker are assigned to the located minimum and maximum transmission areas ad centered at a desired location. The edges of the primitive rectangle are varied to match optimal diffraction orders O(m,n). The optimal CPL mask OCPL(x,y) is then formed.
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Citations
23 Claims
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1. A method for obtaining a lithographic process for creating an image of a pattern at an image plane using a patterning device, the method comprising:
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by a hardware computer system, based on intensities determined for the subset of diffraction orders, selecting one or more illumination points in an illumination system and determining a transmission mask for the pattern, for which minimum image log slope is maximized in the image at each of a plurality of points, wherein determining the transmission mask comprises determining mask diffraction orders, and determining mask diffraction orders comprises performing a non-linear optimization to find optimal diffraction orders, and performing a linear optimization by selecting quantized mask transmission to match the optimal diffraction orders, where the (a) illumination points, (b) the transmission mask, and/or (c) information derived from (a) and/or (b), is configured to design, control and/or modify the physical lithographic process involving the pattern and/or design, control and/or modify a physical object or apparatus to be used in the physical lithographic process. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A non-transitory computer-readable storage medium having stored instructions therein, the instructions, upon execution by a computer system, configured to cause the computer system to at least:
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based on intensities determined for the subset of diffraction orders, select one or more illumination points in an illumination system and determine a transmission mask for a pattern to be imaged to an image plane in a lithographic process using a patterning device, for which minimum image log slope is maximized in the image at each of a plurality of points, wherein determination of the transmission mask comprises determination of mask diffraction orders, and determination of mask diffraction orders comprises performance of a non-linear optimization to find optimal diffraction orders, and perform a linear optimization by selecting quantized mask transmission to match the optimal diffraction orders, where the (a) illumination points, (b) the transmission mask, and/or (c) information derived from (a) and/or (b), is configured to design, control and/or modify the physical lithographic process involving the pattern and/or design, control and/or modify a physical object or apparatus to be used in the physical lithographic process. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A method for obtaining a lithographic process for creating an image of a pattern at an image plane using a patterning device, the method comprising:
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identifying fragmentation points; and by a hardware computer system, selecting one or more illumination points in an illumination system and determining a mask configuration for the pattern, by using a non-linear optimization in a spatial frequency domain, by using kernels derived from diagonalization of transmission cross coefficients of the lithographic process and for which minimum image log slope is maximized in the image at each of the fragmentation points, where the (a) illumination points, (b) the mask configuration, and/or (c) information derived from (a) and/or (b), is configured to design, control and/or modify the physical lithographic process involving the pattern and/or design, control and/or modify a physical object or apparatus to be used in the physical lithographic process. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22)
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23. A non-transitory computer-readable storage medium having stored instructions therein, the instructions, upon execution by a computer system, configured to cause the computer system to at least:
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identifying fragmentation points; and select one or more illumination points in an illumination system and determine a mask configuration for a pattern to be imaged using a lithographic process for creating an image of the pattern using a patterning device, by using a non-linear optimization in a spatial frequency domain, by using kernels derived from diagonalization of transmission cross coefficients of the lithographic process and for which minimum image log slope is maximized in the image at each of the fragmentation points, where the (a) illumination points, (b) the mask configuration, and/or (c) information derived from (a) and/or (b), is configured to design, control and/or modify the physical lithographic process involving the pattern and/or design, control and/or modify a physical object or apparatus to be used in the physical lithographic process.
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Specification