US5862058A
Expired / Lapsed
US
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Optical proximity correction method and system
Assignee: International Business Machines Corp
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Filing: 1996-05-16
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Granted: 1999-01-19
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Expires: 2016-05-16
Abstract
Abstract An optical proximity correction method and system are disclosed that allows for the correction of line width deviations caused by nonlinear lithography tools by calculating required chrome on glass line widths for a desired printed line. Line width correction is determined based only on the pitch of the line, defined as the width of the line and the distance to an adjacent line. Correction information is calculated from an aerial simulation and is then organized by pitch to provide a more efficient means of line correction.
Inventors
- 👤 Donald James Samuels
- 👤 Matthew R. Wordeman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:42
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70483; G03F7/70605; G03F7/70616; G03F7/70625; G03F7/70425; G03F7/70433; G03F7/70441; G03F1/00; G03F1/36
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
199 words
A method of correcting line element deviations during nonlinear operation of an optical lithography system by width adjusting a light blocking material on an optical mask, said method comprising the steps of: choosing a control grating for a predetermined circuit pattern and exposure system, said control grating represented by a control line and a control clear space width; generating expected line deviation information from an aerial simulation for a plurality of line/space gratings wherein said plurality of line/space gratings ranges from said control grating to a region where said optical lithography system operates linearly; generating line correction information from said expected line deviation information wherein said line correction information is grouped into subsets of information, each having a fixed pitch; for at least one line to be placed on said optical mask, determining a line width and distance to an adjacent line; for said at least one line to be placed on said optical mask, using said line correction information to determine a modified line width to correct for line element deviation; and for said at least one line to be placed on said optical mask, adjusting the width of each of said at least one line as necessary.
Claim 2
Independent Claim
199 words
A method of correcting line element deviations during nonlinear operation of an optical lithography system by width adjusting a light blocking material on an optical mask, said method comprising the steps of: choosing a control grating for a predetermined circuit pattern and exposure system, said control grating represented by a control line and a control clear space width; generating expected line deviation information from an aerial simulation for a plurality of line/space gratings wherein said plurality of line/space gratings ranges from said control grating to a region where said optical lithography system operates linearly; generating line correction information from said expected line deviation information wherein said line correction information is grouped into subsets of information, each having a fixed pitch; for at least one line to be placed on said optical mask, determining a line width and distance to an adjacent line; for said at least one line to be placed on said optical mask, using said line correction information to determine a modified line width to correct for line element deviation; and for said at least one line to be placed on said optical mask, adjusting the width of each of said at least one line as necessary.
Claim 3
Dependent Claim
15 words
The method of claim 1 wherein said lines on said optical mask are chrome lines.
Claim 4
Dependent Claim
17 words
The method of claim 1 wherein said lines on said optical mask comprise a light attenuating material.
Claim 5
Dependent Claim
47 words
The method of claim 1 wherein said line correction information is comprised of a look-up graph that includes a plurality of pitch curves, said look-up graph having a first axis representing a desired line width and a second axis representing a required light blocking material line width.
Claim 6
Independent Claim
36 words
The method of claim I wherein said line correction information is comprised of at least one look-up table that is categorized by pitch and provides a required light blocking material width for a desired line width.
Claim 7
Independent Claim
33 words
The method of claim I wherein said line correction information is comprised of at least one pitch specific polynomial equation that calculates a required light blocking material width for a desired line width.
Claim 8
Dependent Claim
54 words
The method of claim 1 further including the step of generating at least one predetermined line width graph having an edge correction curve wherein said at least one predetermined line width graph has a first axis that represents a distance to an adjacent line and a second axis that represents an edge adjustment value.
Claim 9
Dependent Claim
47 words
The method of claim 7 wherein the values on said second axis of said at least one predetermined line width graph are determined by calculating the difference of corresponding points on said second axis of said lookup graph and said desired line width, then dividing by two.
Claim 10
Independent Claim
118 words
A method of generating line width correction information within a computer aided design layout system to correct for printed line deviations caused by the nonlinear operation of an optical lithography system, said method comprising the steps of: selecting an environment, said environment to include at least one optical lithography system parameter and at least one circuit pattern parameter; simulating said environment to generate a plurality of predicted line deviation values as a function of corresponding line/space proportions; and transforming said plurality of predicted line deviation values into line width correction information, wherein the line width correction information is categorized by pitch, the pitch including the width of a printed line and a distance to an adjacent printed line.
Claim 11
Independent Claim
118 words
A method of generating line width correction information within a computer aided design layout system to correct for printed line deviations caused by the nonlinear operation of an optical lithography system, said method comprising the steps of: selecting an environment, said environment to include at least one optical lithography system parameter and at least one circuit pattern parameter; simulating said environment to generate a plurality of predicted line deviation values as a function of corresponding line/space proportions; and transforming said plurality of predicted line deviation values into line width correction information, wherein the line width correction information is categorized by pitch, the pitch including the width of a printed line and a distance to an adjacent printed line.
Claim 12
Dependent Claim
31 words
The method of claim 9 wherein said line width correction information includes a means for determining the required size of a light blocking material to achieve a desired line width size.
Claim 13
Dependent Claim
22 words
The method of claim 10 wherein said line width correction information appears as at least one pitch curve on a look-up graph.
Claim 14
Dependent Claim
15 words
The method of claim 10 wherein said line width correction information is in table format.
Claim 15
Dependent Claim
15 words
The method of claim 10 wherein said line width correction information is in polynomial format.
Claim 16
Dependent Claim
14 words
The method of claim 9 wherein said light blocking material comprises chrome on glass.
Claim 17
Dependent Claim
14 words
The method of claim 9 wherein said light blocking material comprises light attenuating material.
Claim 18
Dependent Claim
88 words
A computer aided design integrated circuit layout tool having an optical lithographic line deviation correction system, said system comprising: a simulation system that generates pitch-based line width correction information for a predetermined exposure system and control grating wherein a pitch includes line width and a distance to an adjacent line; and a calculation system that takes as input a desired line width and a desired distance to an adjacent line and utilizes said pitch-based line width correction information to calculate a required width of a light blocking material.
Claim 19
Dependent Claim
88 words
A computer aided design integrated circuit layout tool having an optical lithographic line deviation correction system, said system comprising: a simulation system that generates pitch-based line width correction information for a predetermined exposure system and control grating wherein a pitch includes line width and a distance to an adjacent line; and a calculation system that takes as input a desired line width and a desired distance to an adjacent line and utilizes said pitch-based line width correction information to calculate a required width of a light blocking material.
Claim 20
Dependent Claim
23 words
The lithographic line deviation correction system of claim 16 wherein said calculation system includes a look-up graph having a plurality of pitch curves.
Claim 21
Dependent Claim
28 words
The lithographic line deviation correction system of claim 16 wherein said calculation system includes a table look-up system for calculating said required width of said light blocking material.
Claim 22
Dependent Claim
27 words
The lithographic line deviation correction system of claim 16 wherein said calculation system includes a polynomial algorithm for calculating said required width of said light blocking material.
Claim 23
Dependent Claim
20 words
The lithographic line deviation correction system of claim 16 wherein said light blocking material is a chrome on glass material.
Claim 24
Dependent Claim
19 words
The lithographic line deviation correction system of claim 16 wherein said light blocking material is a light attenuating material.
Claim 25
Independent Claim
82 words
A method of correcting line element deviations in which line correction information is created for a particular optical lithography system, the method comprising the steps of: simulating operation of the particular optical lithography system to generate a plurality of predicted line deviation values; and converting the plurality of predicted line deviation values into line width correction information based on a combined element of line width and distance to an adjacent line, whereby accurate line correction information is obtained in a single iteration.
Claim 26
Independent Claim
82 words
A method of correcting line element deviations in which line correction information is created for a particular optical lithography system, the method comprising the steps of: simulating operation of the particular optical lithography system to generate a plurality of predicted line deviation values; and converting the plurality of predicted line deviation values into line width correction information based on a combined element of line width and distance to an adjacent line, whereby accurate line correction information is obtained in a single iteration.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-01-18 | 2002-07-20 | 2003-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-01-18 | 2006-07-20 | 2007-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-01-18 | 2010-07-20 | 2011-01-19 | $7700.00 | Window Closed / Lapsed |