METHOD AND APPARATUS FOR PERFORMING MODEL-BASED LAYOUT CONVERSION FOR USE WITH DIPOLE ILLUMINATION
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Accused Products
Abstract
A method of generating complementary masks for use in a multiple-exposure lithographic imaging process. The method includes the steps of: identifying a target pattern having a plurality of features comprising horizontal and vertical edges; generating a horizontal mask based on the target pattern; generating a vertical mask based on the target pattern; performing a shielding step in which at least one of the vertical edges of the plurality of features in the target pattern is replaced by a shield in the horizontal mask, and in which at least one of the horizontal edges of the plurality of features in the target pattern is replaced by a shield in the vertical mask, where the shields have a width which is greater that the width of the corresponding feature in the target pattern; performing an assist feature placement step in which sub-resolution assist features are disposed parallel to at least one of the horizontal edges of the plurality of features in the horizontal mask, and are disposed parallel to at least one of the vertical edges of the plurality of features in the vertical mask, and performing a feature biasing step in which at least one of the horizontal edges of the plurality of features in the horizontal mask are adjusted such that the resulting feature accurately reproduces the target pattern, and at least one of the vertical edges of the plurality of features in the vertical mask are adjusted such that the resulting feature accurately reproduces the target pattern.
30 Citations
45 Claims
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1-24. -24. (canceled)
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25. A method for preparing masks for printing a pattern on a substrate utilizing multiple exposure lithography imaging comprising dipole illumination, the dipole illumination comprising first and second different poles, the pattern being intended to be an accurate reproduction of a design comprising a target pattern having a plurality of features, the method comprising:
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initializing first and second masks for use with the first and second poles of the dipole illumination, respectively, with the plurality of features; and determining shielding to be applied to the initialized first and second masks, including; identifying at least a first one of the plurality of features in the target pattern for treatment with a first shield in the first mask, the first feature having an edge which extends in a direction in the mask that is substantially parallel to the first pole, and using an OPC model to determine dimensions of the first shield. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34)
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36. A method for preparing masks for printing a pattern on a substrate utilizing multiple exposure lithography imaging comprising dipole illumination, the dipole illumination comprising horizontal and vertical poles, the pattern being intended to be an accurate reproduction of a design comprising a target pattern having a plurality of features, the method comprising:
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initializing horizontal and vertical masks for use with the vertical and horizontal poles of the dipole illumination, respectively, with the plurality of features; and determining shielding to be applied to the initialized horizontal and vertical masks, including; identifying at least a first one of the plurality of features in the target pattern for treatment with a first shield in the horizontal mask, the first feature having an edge which extends in a substantially vertical direction in the mask, and using an OPC model to determine dimensions of the first shield. - View Dependent Claims (37, 38, 39, 40, 41, 42, 43, 44)
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45. The method of claim 365, wherein the shielding determination step further includes:
determining not to apply a shield to at least a first different one of the plurality of features in the target pattern in the horizontal mask, the determination being made using the OPC model.
Specification