Efficient way to creating process window enhanced photomask layout
First Claim
1. A method of making a photomask, the method comprising:
- constructing a transmission cross coefficient (TCC) matrix representing an illumination source for supplying light to transmit through the photomask and a pupil for focusing the transmitted light onto a target substrate to produce a set of main features;
generating kernels through decomposition of the TCC matrix;
selecting ones of the kernels having odd symmetry;
generating a field map kernel as a sum of self-convolutions of the odd symmetry kernels;
generating a first field map by convolving an area of the photomask corresponding to the set of main features with the field map kernel; and
making the photomask corresponding to the first field map.
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Accused Products
Abstract
A method of making a photomask includes constructing a transmission cross coefficient (TCC) matrix representing an illumination source for supplying light to transmit through the photomask and a pupil for focusing the transmitted light onto a target substrate to produce a set of main features, generating kernels through decomposition of the TCC matrix, selecting ones of the kernels having odd symmetry, generating a field map kernel as a sum of self-convolutions of the odd symmetry kernels, generating a first field map by convolving an area of the photomask corresponding to the set of main features with the field map kernel, and making the photomask corresponding to the first field map. The method may include assigning first sub-resolution assist features (SRAFs) to those portions of the photomask area having corresponding said first field map values exceeding a nonnegative threshold, and making the photomask corresponding to the main features and first SRAFs.
10 Citations
20 Claims
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1. A method of making a photomask, the method comprising:
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constructing a transmission cross coefficient (TCC) matrix representing an illumination source for supplying light to transmit through the photomask and a pupil for focusing the transmitted light onto a target substrate to produce a set of main features; generating kernels through decomposition of the TCC matrix; selecting ones of the kernels having odd symmetry; generating a field map kernel as a sum of self-convolutions of the odd symmetry kernels; generating a first field map by convolving an area of the photomask corresponding to the set of main features with the field map kernel; and making the photomask corresponding to the first field map. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A system for making a photomask, the system comprising:
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a processor; a non-transitory physical medium, wherein the medium has instructions stored thereon that, when executed by the processor, causes the processor to; construct a transmission cross coefficient (TCC) matrix representing an illumination source for supplying light to transmit through the photomask and a pupil for focusing the transmitted light onto a target substrate to produce a set of main features; generate kernels through decomposition of the TCC matrix; select ones of the kernels having odd symmetry; generate a field map kernel as a sum of self-convolutions of the odd symmetry kernels; and generate a first field map by convolving an area of the photomask corresponding to the set of main features with the field map kernel; and a photomask fabricator configured to make the photomask corresponding to the first field map. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A method of making an integrated circuit (IC) chip on a silicon wafer, the method comprising:
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making one or more photomasks, the making of each of the one or more photomasks comprising; constructing a transmission cross coefficient (TCC) matrix representing an illumination source for supplying light to transmit through the photomask and a pupil for focusing the transmitted light onto a target substrate to produce a set of main features; generating kernels through decomposition of the TCC matrix; selecting ones of the kernels having odd symmetry; generating a field map kernel as a sum of self-convolutions of the odd symmetry kernels; generating a first field map by convolving an area of the photomask corresponding to the set of main features with the field map kernel; and making the photomask corresponding to the first field map; and using the one or more photomasks to fabricate the IC chip on the silicon wafer using photolithography. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification