Optical proximity correction during wafer processing through subfile bias modification with subsequent subfile merging
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChia Hui Lin, San-De Tzu, Chih-Chiang Tu
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Abstract
Improvement in the quality of photoresist images has been achieved. The data file in which the full description of the photoresist image, including Optical Proximity Corrections, has been stored is split into two subfiles. The split is made on the basis of separating cell descriptions (where the density of lines is high) from peripheral area descriptions (where lines tend to be isolated). A suitable bias in the form of a small increase or decrease (as appropriate) of all dimensions in the subfile is then applied. After the application of bias, the subfiles are merged back into a single data file and processing proceeds as usual.
Claims15
A method for correcting the proximity effect in circuit patterns, comprising:
- storing a description of a circuit pattern in a data file that comprises cell areas and peripheral areas;
- modifying the data file by applying an Optical Proximity Correction to it;
- dividing the corrected data file into first and second subfiles whereby the first subfile contains data relating to the cell areas and the second subfile contains data relating to the peripheral areas;
- modifying the first subfile by applying a first bias to all data contained therein;
- modifying the second subfile by applying a second bias to all data contained therein;
- and
- combining said first and second subfiles into a single merged data file.
A method for forming a photoresist pattern on a substrate, comprising:
- coating the substrate with a layer of the photoresist;
- storing a description of a photoresist image in a data file that comprises cell areas and peripheral areas;
- modifying the data file by applying an Optical Proximity Correction to it;
- dividing the corrected data file into first and second subfiles whereby the first subfile contains data relating to the cell areas and the second subfile contains data relating to the peripheral areas;
- modifying the first subfile by applying a first bias to all data contained therein;
- modifying the second subfile by applying a second bias to all data contained therein;
- combining said first and second subfiles into a single merged data file;
- forming a photoresist mask using the merged file;
- exposing said layer of photoresist to radiation through the mask;
- and
- developing the exposed photoresist so as to form the pattern.
Dependencies are inferred from the claim text.