EP1439419A2
Expired / Lapsed
EP
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Method and apparatus for providing optical proximity correction features to a reticle pattern for optical lithography
Assignee: ASML MaskTools Netherlands BV
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Filing: 2004-01-14
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Granted: —
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Expires: 2024-01-14
Abstract
Abstract A method of generating a mask design having optical proximity correction features disposed therein. The methods includes the steps of obtaining a desired target pattern having features to be imaged on a substrate; determining an interference map based on the target pattern, the interference map defining areas of constructive interference and areas of destructive interference between at least one of the features to be imaged and a field area adjacent the at least one feature; and placing assist features in the mask design based on the areas of constructive interference and the areas of destructive interference.
Inventors
- 👤 Douglas Van Den Broeke
- 👤 Jang Fung Chen
- 👤 Thomas Laidig
- 👤 Kurt E. Wampler
- 👤 Duan-Fu Stephen Hsu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 11:21
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/36; G03F1/68; G03F1/82; G03F1/84; G03F7/00; G03F7/70; G03F7/70425; G03F7/70433; G03F7/70441; G03F7/70483; G03F7/70491; G03F7/705
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
96 words
A method of generating a mask design having optical proximity correction
features disposed therein, said method comprising the steps of: obtaining a desired target pattern having features to be imaged on a substrate; determining an interference map based on said target pattern, said interference map
defining areas of constructive interference and areas of destructive interference between at
least one of said features to be imaged and a field area adjacent said at least one feature;
and placing assist features in the mask design based on the areas of constructive
interference and the areas of destructive interference.
Claim 2
Dependent Claim
95 words
A method according to claim 1, wherein the step of determining the interference
map comprising the steps of: reducing the size of the features contained in the desired target pattern such that the
size of the features are less than the resolution capability of an image system to be utilized
to image the mask, thereby generating a reduced size target pattern; and performing an optical simulation of the reduced size target pattern, said simulation
being performed such that the field area of the reduced size target pattern has percentage
transmission which is greater than zero.
Claim 3
Dependent Claim
49 words
A method according to claim 2, wherein the critical dimensions of the features
contained in the reduced size target pattern are less than λ/(2π•NA), where λ is the exposure
wavelength of the imaging tool and NA stands for the numerical aperture of a projection
lens of the image system
Claim 4
Dependent Claim
38 words
A method according to claim 1, 2 or 3 wherein said interference map also
defines neutral areas of interference, said neutral areas not resulting in either constructive
interference or destructive interference relative to the feature to be imaged.
Claim 5
Dependent Claim
30 words
A method according to claim 1, 2, 3 or 4 wherein said assist features to be
disposed in said mask design comprises scatter bars, anti-scatter bars and non-printing
assist features.
Claim 6
Dependent Claim
40 words
A method according to claim 5, wherein assist features which enhance the
printing of said feature to be imaged are disposed in constructive areas of interferences,
and assist features which negate destructive interference are disposed in destructive areas
of interference.
Claim 7
Independent Claim
94 words
A method according to any one of the preceding claims, wherein the
interference map defines intensity levels of the field relative to the featured to be images,
said interference map being capable of representing both positive and negative values of
intensity relative to a non-zero DC level, wherein regions of the field having intensity values which are positive relative to
said non-zero DC level correspond to constructive areas of interference, and regions of the
field having intensity values which are negative relative to said non-zero DC level
correspond to destructive areas of interference areas.
Claim 8
Independent Claim
23 words
A method according to any one of the preceding claims further comprising
the step of making a mask according to the mask design.
Claim 9
Independent Claim
32 words
A method according to any one of claims 1 to 7 further comprising the step
of generating a data file representing the mask design for use in controlling a
programmable patterning means.
Claim 10
Independent Claim
102 words
An apparatus for generating a mask design having optical proximity correction
features disposed therein, said apparatus comprising the steps of: means for obtaining a desired target pattern having features to be imaged on a
substrate; means for determining an interference map based on said target pattern, said
interference map defining areas of constructive interference and areas of destructive
interference between at least one of said features to be imaged and a field area adjacent
said at least one feature; and means for placing assist features in the mask design based on the areas of
constructive interference and the areas of destructive interference.
Claim 11
Dependent Claim
88 words
Apparatus according to claim 10, wherein determining the interference map
includes: reducing the size of the features contained in the desired target pattern such that the
size of the features are less than the resolution capability of an image system to be utilized
to image the mask, thereby generating a reduced size target pattern; and performing an optical simulation of the reduced size target pattern, said simulation
being performed such that the field area of the reduced size target pattern has percentage
transmission which is greater than zero.
Claim 12
Dependent Claim
48 words
Apparatus according to claim 11, wherein the critical dimensions of the
features contained in the reduced size target pattern are less than λ/(2π•NA), where λ is the
exposure wavelength of the imaging tool and NA stands for the numerical aperture of a
projection lens of the image system
Claim 13
Dependent Claim
37 words
Apparatus according to claim 10, 11 or 12 wherein said interference map also
defines neutral areas of interference, said neutral areas not resulting in either constructive
interference or destructive interference relative to the feature to be imaged.
Claim 14
Dependent Claim
29 words
Apparatus according to claim 10, 11, 12 or 13, wherein said assist features to
be disposed in said mask design comprises scatter bars, anti-scatter bars and non-printing
assist features.
Claim 15
Dependent Claim
39 words
Apparatus according to claim 14, wherein assist features which enhance the
printing of said feature to be imaged are disposed in constructive areas of interferences,
and assist features which negate destructive interference are disposed in destructive areas
of interference.
Claim 16
Dependent Claim
94 words
Apparatus according to any one of claims 10 to 15, wherein the interference
map defines intensity levels of the field relative to the featured to be images, said
interference map being capable of representing both positive and negative values of
intensity relative to a non-zero DC level, wherein regions of the field having intensity values which are positive relative to
said non-zero DC level correspond to constructive areas of interference, and regions of the
field having intensity values which are negative relative to said non-zero DC level
correspond to destructive areas of interference areas.
Claim 17
Dependent Claim
31 words
A computer program comprising code means that, when executed on a
computer system, instruct the computer system to effect the method of any one of claims 1
to 7 or 9.
References Cited (Backward Citations)
No citation records indexed.
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