US 8,411,253 B2Granted

Computer readable medium and exposure method

AssigneeCanon Kabushiki Kaisha

InventorsYoshiyuki Sekine, Kenji Yamazoe

Life of this patent

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Abstract

A computer readable medium containing computer-executable instructions which cause a computer to execute processing steps that calculate a light intensity distribution formed on an image plane of a projection optical system. When executed, the medium causes a computer to execute the steps of dividing an effective light source into the plurality of areas, generating, for each of the plurality of areas, a plurality of shifted pupil functions by shifting a pupil function in accordance with a position of each of divided point sources, defining, for each of the plurality of areas, a matrix including the plurality of pupil functions, calculating, for each of the plurality of areas, eigenvalues and eigenfunctions by performing singular value decomposition of the matrix, and calculating, for each of the plurality of areas, the light intensity distribution based on a diffracted light distribution from the mask and the eigenvalues and the eigenfunctions.

Claims11

Dependent claims

A non-transitory computer readable medium containing computer-executable instructions which cause a computer to execute processing steps that calculate a light intensity distribution formed on an image plane of a projection optical system when illuminating a mask using an illumination optical system and projecting an image of a pattern of the mask onto a substrate through the projection optical system, the computer readable medium comprising:

computer-executable instructions that determine whether to divide an effective light source into a plurality of areas, the effective light source being formed on a pupil plane of the projection optical system when the mask is not arranged on an object plane of the projection optical system;
computer-executable instructions that divide the effective light source into the plurality of areas upon determining to divide the effective light source into the plurality of areas;
computer-executable instructions that generate, for each of the plurality of areas, a plurality of shifted pupil functions by shifting a pupil function representing a pupil of the projection optical system in accordance with a position of each of divided point sources;
computer-executable instructions that define, for each of the plurality of areas, a matrix including the plurality of shifted pupil functions generated in the generating step by arranging each of the plurality of shifted pupil functions generated in the generating step in each row or each column of the matrix;
computer-executable instructions that compress the defined matrix, for each of the plurality of areas, by deleting a row or a column of the matrix in which all elements are 0;
computer-executable instructions that calculate, for each of the plurality of areas, eigenvalues and eigenfunctions by performing singular value decomposition of the compressed matrix;
computer-executable instructions that calculate, for each of the plurality of areas, the light intensity distribution formed on the image plane of the projection optical system based on a diffracted light distribution of light diffracted by the pattern of the mask and the eigenvalues and the eigenfunctions calculated in the step of calculating the eigenvalues and the eigenfunctions;
and
computer-executable instructions that composite the light intensity distributions of the plurality of areas which are calculated in the step of calculating the light intensity distributions.

6 more elements

A computer-implemented method of calculating a light intensity distribution formed on an image plane of a projection optical system when illuminating a mask using an illumination optical system and projecting an image of a pattern of the mask onto a substrate through the projection optical system, the method comprising:

determining whether to divide an effective light source into a plurality of areas, the effective light source being formed on a pupil plane of the projection optical system when the mask is not arranged on an object plane of the projection optical system;
dividing the effective light source into the plurality of areas upon determining to divide the effective light source into the plurality of areas;
generating, for each of the plurality of areas, a plurality of shifted pupil functions by shifting a pupil function representing a pupil of the projection optical system in accordance with a position of each of divided point sources;
defining, for each of the plurality of areas, a matrix including the plurality of shifted pupil functions generated in the generating step by arranging each of the plurality of shifted pupil functions generated in the generating step in each row or each column of the matrix;
compressing the defined matrix, for each of the plurality of areas, by deleting a row or a column of the matrix in which all elements are 0;
calculating, for each of the plurality of areas, eigenvalues and eigenfunctions by performing singular value decomposition of the compressed matrix;
calculating, for each of the plurality of areas, the light intensity distribution formed on the image plane of the projection optical system based on a diffracted light distribution of light diffracted by the pattern of the mask and the eigenvalues and the eigenfunctions calculated in the step of calculating the eigenvalues and the eigenfunctions;
and
compositing the light intensity distributions of the plurality of areas which are calculated in the step of calculating the light intensity distributions.

6 more elements

dividing an effective light source into a plurality of areas, and dividing the effective light source into a plurality of point sources in each of the plurality of areas, the effective light source being formed on a pupil plane of the projection optical system when the mask is not arranged on an object plane of the projection optical system;
generating , for each of the plurality of areas, a plurality of shifted pupil functions by shifting a pupil function representing a pupil of the projection optical system in accordance with a position of each of the point sources;
defining , for each of the plurality of areas, a matrix including the plurality of shifted pupil functions generated in the generating step by arranging each of the plurality of shifted pupil functions generated in the generating step in each row or each column of the matrix;
compressing the defined matrix, for each of the plurality of areas, by deleting a row or a column of the matrix in which all elements are 0;
calculating, for each of the plurality of areas, eigenvalues and eigenfunctions by performing singular value decomposition of the compressed matrix;
calculating , for each of the plurality of areas, the light intensity distribution formed on the image plane of the projection optical system based on a diffracted light distribution of light diffracted by the pattern of the mask and the eigenvalues and the eigenfunctions calculated in the step of calculating the eigenvalues and the eigenfunctions;
and
compositing the light intensity distributions of the plurality of areas which are calculated in the step of calculating the light intensity distributions.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/492,736Filed 26 Jun 2009
Priority: JP 2008-18415215 Jul 2008
Published: US 2010/0053580 A14 Mar 2010
Granted: 2 Apr 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification3 codes

G03F 7/70666
Metrology techniques: aerial image, i.e. measuring the image of the patterned exposure light at the image plane of the projection system
G03F 7/705
Information management, e.g. software; Active and passive control, e.g. details of controlling exposure processes or exposure tool monitoring…:…
G03F
Photomechanical production of textured or patterned surfaces