Modeling an arbitrarily polarized illumination source in an optical lithography system
AssigneeSynopsys, Inc.
InventorsQiaolin Zhang, Hua Song
Life of this patent
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Abstract
One embodiment of the present invention provides a system that accurately models polarization states of an illumination source in an optical lithography system for manufacturing integrated circuits. During operation, the system starts by receiving a two-dimensional (2D) grid map for an illumination source pupil in the optical lithography system. The system then constructs a source-polarization model for the illumination source by defining a polarization state at each grid point in the grid map. Next, the system enhances a lithography model for the optical lithography system by incorporating the source-polarization model into the lithography/OPC model.
Claims20
A method for accurately modeling polarization states of an illumination source in an optical lithography system for manufacturing integrated circuits, the method comprising:
- receiving a two-dimensional (2D) grid map for a modified illumination source in the optical lithography system, wherein the 2D grid map comprises a 2D array of grid points, wherein each grid point represents a location in the modified illumination source;
- constructing a source-polarization model for the modified illumination source by defining a polarization state at each grid point in the 2D grid map to facilitate a point-by-point description of the modified illumination source;
- decomposing the modified illumination source at each grid point into an unpolarized component and a completely polarized component;
- and
- enhancing a lithography model for the optical lithography system by incorporating the source-polarization model into the lithography model, which involves separately applying a transfer matrix associated with the optical lithography system to the unpolarized component and to the completely polarized component.
A non-transitory computer readable storage medium storing instructions that when executed by a computer cause the computer to perform a method for accurately modeling polarization states of an illumination source in an optical lithography system for manufacturing integrated circuits, the method comprising:
- receiving a 2D grid map for a modified illumination source in the optical lithography system, wherein the 2D grid map comprises a 2D array of grid points, wherein each grid point represents a location in the modified illumination source;
- constructing a source-polarization model for the modified illumination source by defining a polarization state at each grid point in the 2D grid map to facilitate a point-by-point description of the modified illumination source;
- decomposing the modified illumination source at each grid point into an unpolarized component and a completely polarized component;
- and
- enhancing a lithography model for the optical lithography system by incorporating the source-polarization model into the lithography model, which involves separately applying a transfer matrix associated with the optical lithography system to the unpolarized component and to the completely polarized component.
An apparatus that accurately models polarization states of an illumination source in an optical lithography system for manufacturing integrated circuits, comprising:
- a computer;
- a receiving mechanism implemented on the computer and configured to receive a 2D grid map on a modified illumination source in the optical lithography system, wherein the 2D grid map comprises a 2D array of grid points, wherein each grid point represents a location in the modified illumination source;
- a constructing mechanism implemented on the computer and configured to construct a source-polarization model for the modified illumination source by defining a polarization state at each grid point in the 2D grid map to facilitate a point-by-point description of the modified illumination source;
- a decomposition mechanism implemented on the computer and configured to decompose the modified illumination source at each grid point into an unpolarized component and a completely polarized component;
- and
- an incorporating mechanism implemented on the computer and configured to enhance a lithography model for the optical lithography system by incorporating the source-polarization model into the lithography model which involves separately applying a transfer matrix associated with the optical lithography system to the unpolarized component and to the completely polarized component.
A method for accurately modeling polarization states of an illumination source in an optical lithography system for manufacturing integrated circuits, the method comprising:
- receiving a two-dimensional (2D) grid map for a modified illumination source in the optical lithography system, wherein the 2D grid map comprises a 2D array of grid points, wherein each grid point represents a location in the modified illumination source;
- constructing a source-polarization model for the modified illumination source by defining a polarization state at each grid point in the 2D grid map to facilitate a point-by-point description of the modified illumination source;
- decomposing the modified illumination source at each grid point into an unpolarized component and a completely polarized component;
- building a first model for the unpolarized component;
- and
- building a second model for the completely polarized component;
- wherein an image intensity on a wafer due to an arbitrarily polarized illumination source is a sum of contributions from the first and second models.
Dependencies are inferred from the claim text.