DESIGN LAYOUT PATTERN PROXIMITY CORRECTION THROUGH FAST EDGE PLACEMENT ERROR PREDICTION
First Claim
1. A method of generating a look-up table (LUT) associating, for a plurality of features on a semiconductor substrate surface, values of one or more quantities characteristic of an edge placement error (EPE) with values of one or more quantities characteristic of in-feature plasma flux (IFPF), the features to be etched into a material stack on said substrate via a plasma-based etch process performed in a processing chamber under a set of process conditions, the method comprising:
- (a) receiving the set of process conditions and the material stack composition;
(b) receiving a pattern of photoresist defining a set of features;
(c1) calculating a first IFPF-characteristic (IFC) value, the first IFC value corresponding to a first quantity characteristic of IFPF during the etch, under the set of process conditions, of a first selected feature from the set of features;
(c2) calculating a second IFC value, the second IFC value corresponding to the first characteristic of IFPF during the etch, under the set of process conditions, of a second selected feature from the set of features;
(d1) including a first entry in the LUT associated with an edge of the first selected feature, the first entry comprising;
the first IFC value; and
a first EPE-characteristic (EPC) value corresponding to a quantity characteristic of an EPE of the edge of the first selected feature, said first EPC value generated by running a computerized etch profile model (EPM) to simulate etching under the set of process conditions of the material stack as overlaid with at least the portion of the pattern of photoresist corresponding to the first selected feature; and
(d2) determining to not include an entry in the LUT associated with an edge of the second selected feature and comprising the second IFC value, the determining based, at least in part, on the similarity of the second IFC value to the first IFC value.
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Accused Products
Abstract
Disclosed are methods of generating a proximity-corrected design layout for photoresist to be used in an etch operation. The methods may include identifying a feature in an initial design layout, and estimating one or more quantities characteristic of an in-feature plasma flux (IFPF) within the feature during the etch operation. The methods may further include estimating a quantity characteristic of an edge placement error (EPE) of the feature by comparing the one or more quantities characteristic of the IFPF to those in a look-up table (LUT, and/or through application of a multivariate model trained on the LUT, e.g., constructed through machine learning methods (MLM)) which associates values of the quantity characteristic of EPE with values of the one or more quantities characteristics of the IFPF. Thereafter, the initial design layout may be modified based on at the determined quantity characteristic of EPE.
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Citations
30 Claims
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1. A method of generating a look-up table (LUT) associating, for a plurality of features on a semiconductor substrate surface, values of one or more quantities characteristic of an edge placement error (EPE) with values of one or more quantities characteristic of in-feature plasma flux (IFPF), the features to be etched into a material stack on said substrate via a plasma-based etch process performed in a processing chamber under a set of process conditions, the method comprising:
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(a) receiving the set of process conditions and the material stack composition; (b) receiving a pattern of photoresist defining a set of features; (c1) calculating a first IFPF-characteristic (IFC) value, the first IFC value corresponding to a first quantity characteristic of IFPF during the etch, under the set of process conditions, of a first selected feature from the set of features; (c2) calculating a second IFC value, the second IFC value corresponding to the first characteristic of IFPF during the etch, under the set of process conditions, of a second selected feature from the set of features; (d1) including a first entry in the LUT associated with an edge of the first selected feature, the first entry comprising; the first IFC value; and a first EPE-characteristic (EPC) value corresponding to a quantity characteristic of an EPE of the edge of the first selected feature, said first EPC value generated by running a computerized etch profile model (EPM) to simulate etching under the set of process conditions of the material stack as overlaid with at least the portion of the pattern of photoresist corresponding to the first selected feature; and (d2) determining to not include an entry in the LUT associated with an edge of the second selected feature and comprising the second IFC value, the determining based, at least in part, on the similarity of the second IFC value to the first IFC value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A look-up table (LUT) comprising a plurality of entries corresponding to a plurality of edges of a plurality of features to be etched into a material stack on a semiconductor substrate surface via a plasma-based etch process performed in a processing chamber under a set of process conditions, the entries comprising a plurality of fields, the fields comprising:
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an EPE field holding a value of a quantity characteristic of an edge placement error (EPE); and one or more IFPF fields holding values of one or more quantities characteristic of an in-feature plasma flux (IFPF), the fields selected from; an IFPIF field for holding a value of a quantity characteristic of in-feature plasma ion flux (IFPIF); an IFPNF field for holding a value of a quantity characteristic of in-feature plasma neutral flux (IFPNF); and an IFPDF field for holding a value of a quantity characteristic of in-feature passivant deposition flux (IFPDF); wherein the average relative difference between pairs of nearest values held in fields of the table corresponding to each quantity characteristic of IFPF is greater than 5%.
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24. A method of identifying a subset of entries from a set of potential entries for use in a look-up table (LUT) or other framework for characterizing an etch process, the entries corresponding to a plurality of edges of a plurality of features to be etched into a material stack on a semiconductor substrate surface via a plasma-based etch process performed in a processing chamber under a set of process conditions, each entry comprising:
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a value of a quantity characteristic of an edge placement error (EPE) of an edge of a feature; and a value of a quantity characteristic of an in-feature plasma flux (IFPF) during said etching of the feature; the method comprising; for each potential entry, calculating a sensitivity metric for the entry, the sensitivity metric indicative of the magnitude of the partial derivative of the quantity characteristic of EPE with respect to the quantity characteristic of IFPF (d[EPE]/d[IFPF]) evaluated at the value of the quantity characteristic of IFPF; and selecting a subset of entries from the set of potential entries such that the average of the sensitivity metric over the subset is higher than the average of the sensitivity metric over the full set. - View Dependent Claims (25, 26, 27, 28, 29)
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30. A method of detecting high sensitivity regions in a plurality of features to be etched into a material stack on a semiconductor substrate surface via a plasma-based etch process performed in a processing chamber under a set of process conditions, a high sensitivity region corresponding to an edge of a feature which is particularly sensitive to etch process conditions, the method comprising:
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choosing a plurality of potential high sensitivity regions in the plurality of features, each potential high sensitivity region corresponding to a particular edge of a feature; for each potential high sensitivity region, calculating a sensitivity metric corresponding to the particular edge associated with the potential high sensitivity region, the sensitivity metric indicative of the magnitude of an estimated partial derivative of a quantity characteristic of an edge placement error (EPE) corresponding to the edge with respect to a quantity characteristic of an in-feature plasma flux (IFPF) corresponding to the feature, said partial derivative estimated with respect to a value of said quantity characteristic of IFPF corresponding to the feature and chosen process conditions; and identifying high sensitivity regions in the plurality of potential high sensitivity regions based on the sensitivity metric.
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Specification