Optical proximity correction method
AssigneeUnited Microelectronics Corp.
InventorChin-Lung Lin
Life of this patent
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Abstract
An optical proximity correction method. Assist features, such as scattering bars, are added to a main pattern to be transferred. Calculations are performed on the entire two-dimensional original pattern using model-based optical proximity correction. A series of features are added according to the specific reference indexes of the coordinate system. The original pattern is altered to form a corrected pattern. The process of calculation and correction, however, does not include the scattering bars.
Claims14
An optical proximity correction method comprising the steps of:
- providing a layout pattern having at least a feature;
- inspecting each feature's line width;
- adding an assist feature to those features on the layout pattern whose line width is smaller than the wave-length of a light source used for exposure;
- and
- calculating and correcting the layout pattern to which assist features have been added, using a model-based optical proximity correction method, wherein calculations and corrections using the model-based optical proximity correction method are performed on the layout pattern but not on the assist features.
A method for designing a photomask using a simulator comprising:
- providing a layout pattern having at least a feature;
- inspecting each feature's line width;
- adding an assist feature to those features on the layout pattern whose line width is smaller than the wave-length of a light source used for exposure;
- calculating and correcting the layout pattern to which assist features have been added, using the model-based optical proximity correction method, wherein calculations and corrections using the model-based optical proximity method are performed are performed on the layout pattern but not on the assist features;
- and
- manufacturing a photomask using the corrected layout pattern.
A method for designing a photomask using a simulator comprising:
- providing a layout pattern having at least one feature;
- inspecting a line width of each feature;
- adding assist features to each features on the layout pattern whose line width is smaller than the wave-length of a light source used for exposure;
- calculating and correcting the layout pattern to which assist features have been added, using the model-based optical proximity correction method;
- and
- manufacturing a photomask using the corrected layout pattern.
Dependencies are inferred from the claim text.