US5700602A
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US
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Method and apparatus for precision determination of phase-shift in a phase-shifted reticle
Assignee: Intel Corp
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Filing: 1995-10-30
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Granted: 1997-12-23
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Expires: 2015-10-30
Abstract
Abstract A metrology pattern on a reticle comprising a phase-shifted feature and an additional phase-shifted feature and/or non phase-shifted feature is disclosed. The metrology pattern can be used to determine the target thickness for achieving 180° phase difference, i.e., zero phase error on a phase-shifted reticle. A test reticle having several such metrology patterns, with several different phase-shifter thickness differences is used to produce a CD versus defocus data for each of the phase-shifter thickness differences by performing an exposure matrix or series of aerial images. The data can be used to determine a target thickness for zero phase error. The data can also be used to determine a correlation between focal shift, phase error, and shifter thickness. The metrology pattern can be placed on reticles used for the fabrication of semiconductor devices, for example, so that an exposure matrix can be performed, to determine any focal shift, which can then be related to phase error.
Inventors
- 👤 Giang T. Dao
- 👤 Nelson N. Tam
- 👤 Gang Liu
- 👤 Jeffrey N. Farnsworth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:13
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/26; G03F1/29; G03F1/30; G03F7/00; G03F7/70; G03F7/70216; G03F7/70283; G03F7/70483; G03F7/70605; G03F7/70616; G03F7/70625; G03F7/70641
Claims Analysis
Total Claims: 58
Claim 1
Independent Claim
74 words
A method of determining phase-shift in a phase-shifted reticle comprising the steps of: providing on said reticle a first feature, said first feature being a phase-shifted feature; providing on said reticle a second feature; measuring a first dimension of a first image of said first feature and a second dimension of a second image of said second feature; and determining said phase-shift based upon a comparison of said first dimension and said second dimension.
Claim 2
Independent Claim
74 words
A method of determining phase-shift in a phase-shifted reticle comprising the steps of: providing on said reticle a first feature, said first feature being a phase-shifted feature; providing on said reticle a second feature; measuring a first dimension of a first image of said first feature and a second dimension of a second image of said second feature; and determining said phase-shift based upon a comparison of said first dimension and said second dimension.
Claim 3
Dependent Claim
73 words
The method as described in claim 1 wherein a plurality of said first features are provided on said reticle, wherein the magnitude of said phase-shift of at least one of said first features is different from the magnitude of said phase-shift of another of said first features, and wherein said method further comprises the step of measuring said first dimension of said first image for each of said plurality of said first features.
Claim 4
Dependent Claim
76 words
The method as described in claim 2 wherein said first dimension of said first feature is measured at a plurality focal distances for each of said plurality of said first features, to form a first dimension versus focal distance relationship for each of said first features, and wherein said second dimension of said second feature is measured at said plurality of focal distances to form a second dimension versus focal difference relationship for said second feature.
Claim 5
Dependent Claim
40 words
The method as described in claim 3 wherein a focal shift is determined for each of said plurality of first features by comparing each of said first dimension versus focal distance relationships to said second dimension versus focal distance relationship.
Claim 6
Dependent Claim
21 words
The method of claim 4 wherein said method further comprises the step of determining a focal shift versus phase error relationship.
Claim 7
Dependent Claim
104 words
The method as described in claim 5 wherein said phase-shift of said plurality of first features is created by a thickness of a material, and wherein said step of determining said focal shift versus phase error relationship is determined by: correlating said focal shift of each of said first features with said thickness of each of said first features; determining a zero phase error thickness value; and, determining phase error for each of said plurality of first features by comparing said thickness of each of said first features to said zero phase error thickness value to produce said focal shift versus phase error relationship.
Claim 8
Dependent Claim
66 words
The method as described in claim 6 further comprising the steps of: producing a correlation between said thickness and said phase error; providing a second reticle having a second reticle phase-shifted feature; measuring a second reticle thickness of said second reticle phase-shifted feature; and, determining a second reticle phase error by comparing said second reticle thickness to said correlation between said thickness and said phase error.
Claim 9
Dependent Claim
60 words
The method as described in claim 7 wherein each of said plurality of first features comprises a first reticle dimension corresponding to said first dimension of said first image, and said second feature comprises a second reticle dimension corresponding to said second dimension of said second image, wherein said first reticle dimension and said second reticle dimension are approximately equal.
Claim 10
Dependent Claim
152 words
The method as described in claim 6 further comprising the steps of: providing a second reticle having said first feature and said second feature; measuring said first dimension of said first feature and said second dimension of said second feature on said second reticle at a second plurality of focal distances to form a second reticle first dimension versus focal distance relationship for said first feature on said second reticle and a second reticle second dimension versus focal distance relationship for said second feature on said second reticle; determining a focal shift of said first feature by comparing said second reticle first dimension versus focal distance relationship for said first feature on said second reticle to said second reticle second dimension versus focal distance relationship for said second feature on said second reticle; and, determining a phase error of said second reticle by comparison to said focal shift versus phase error relationship.
Claim 11
Dependent Claim
60 words
The method as described in claim 6 wherein each of said plurality of first features comprises a first reticle dimension corresponding to said first dimension of said first image, and said second feature comprises a second reticle dimension corresponding to said second dimension of said second image, wherein said first reticle dimension and said second reticle dimension are approximately equal.
Claim 12
Dependent Claim
136 words
The method as described in claim 5 further comprising the steps of: providing a second reticle having said first feature and said second feature; measuring said first dimension of said first feature and said second dimension of said second feature on said second reticle at a second plurality of focal distances to form a second reticle first dimension versus focal distance relationship for said first feature on said second reticle and a second reticle second dimension versus focal distance relationship for said second feature on said second reticle; determining a focal shift of said first feature by comparing said second reticle first dimension versus focal distance relationship to said second reticle second dimension versus focal distance relationship; and, determining a phase error of said second reticle by comparison to said focal shift versus phase error relationship.
Claim 13
Dependent Claim
60 words
The method as described in claim 5 wherein each of said plurality of first features comprises a first reticle dimension corresponding to said first dimension of said first image, and said second feature comprises a second reticle dimension corresponding to said second dimension of said second image, wherein said first reticle dimension and said second reticle dimension are approximately equal.
Claim 14
Dependent Claim
60 words
The method as described in claim 2 wherein each of said plurality of first features comprises a first reticle dimension corresponding to said first dimension of said first image, and said second feature comprises a second reticle dimension corresponding to said second dimension of said second image, wherein said first reticle dimension and said second reticle dimension are approximately equal.
Claim 15
Dependent Claim
66 words
The method as described in claim 1 wherein said first dimension of said first feature is measured at a plurality of focal distances to form a first dimension versus focal distance relationship for said first feature, and wherein said second dimension of said second feature is measured at said plurality of focal distances to form a second dimension versus focal distance relationship for said second feature.
Claim 16
Dependent Claim
96 words
The method as described in claim 1 wherein said first dimension of said first feature and said second dimension of said second feature are measured at a plurality of focal distances to form a first relationship of dimension versus focal distance for said first feature, and a second relationship of dimension versus focal distance for said second feature, wherein said method comprises determining a focal shift by comparing said first relationship and said second relationship, and wherein said step of determining said phase-shift comprises comparing said focal shift to a focal shift versus phase error relationship.
Claim 17
Dependent Claim
56 words
The method as described in claim 1 wherein said first feature comprises a first reticle dimension corresponding to said first dimension of said first image, and said second feature comprises a second reticle dimension corresponding to said second dimension of said second image, wherein said first reticle dimension and said second reticle dimension are approximately equal.
Claim 18
Independent Claim
125 words
A method of determining phase-shift in a phase-shifted reticle comprising the steps of: providing on said reticle a first feature, said first feature being a phase-shifted feature; providing on said reticle a second feature; providing on said reticle a third feature, said third feature being a phase-shifted feature, wherein said phase-shift of said first feature is in an opposite direction of said phase-shift of said second feature; measuring a first dimension of a first image of said first feature, a second dimension of a second image of said second feature, and third dimension of a third image of said third feature; and, determining said phase-shift based upon a comparison of said third dimension to one or both of said first dimension and said second dimension.
Claim 19
Independent Claim
125 words
A method of determining phase-shift in a phase-shifted reticle comprising the steps of: providing on said reticle a first feature, said first feature being a phase-shifted feature; providing on said reticle a second feature; providing on said reticle a third feature, said third feature being a phase-shifted feature, wherein said phase-shift of said first feature is in an opposite direction of said phase-shift of said second feature; measuring a first dimension of a first image of said first feature, a second dimension of a second image of said second feature, and third dimension of a third image of said third feature; and, determining said phase-shift based upon a comparison of said third dimension to one or both of said first dimension and said second dimension.
Claim 20
Dependent Claim
108 words
The method as described in claim 17 wherein a plurality of sets of said first features and said third features are provided on said reticle, wherein the magnitude of said phase-shift of said first feature and said third feature in each of said plurality of sets is approximately equal, and wherein the magnitude of said phase-shift of at least one of said sets is different from the magnitude of said phase-shift of another of said sets, and wherein said method further comprises the step of measuring said first dimension of said first image and said third dimension of said third image for each of said plurality of sets.
Claim 21
Dependent Claim
115 words
The method as described in claim 18 wherein said first dimension of said first feature is measured at a plurality of focal distances for each of said plurality of first features to form a first dimension versus focal distance relationship for each of said first features, wherein said second dimension of said feature is measured at said plurality of focal distances to form a second dimension versus focal distance relationship for said second feature, and wherein said third dimension of said third feature is measured at said plurality of focal distances for each of said plurality of said third features to form a third dimension versus focal distance relationship for each of said third features.
Claim 22
Dependent Claim
96 words
The method as described in claim 19 wherein a focal shift is determined for each of said plurality of first features by comparing each of said first dimension versus focal distance relationships to one or both of said second dimension versus focal distance and said third dimension versus focal distance relationships, and wherein a focal shift is determined for each of said plurality of third features by comparing each of said third dimension versus focal shift relationships to one or both of said first dimension versus focal distance and said second dimension versus focal distance relationships.
Claim 23
Dependent Claim
20 words
The method as described in claim 20 wherein said method further comprises determining a focal shift versus phase error relationship.
Claim 24
Dependent Claim
121 words
The method as described in claim 21 wherein said phase-shift of said plurality of first features is created by a thickness of a material, and wherein said step of determining said focal shift versus phase error relationship is determined by: correlating said focal shift of each of said first features and said third feature with said thickness of each of said first features and said third features, respectively; determining a zero phase error thickness value; and, determining phase error for each of said plurality of first features and said third features by comparing said thickness of each of said first features and said third features to said zero phase error thickness value to produce said focal shift versus phase error relationship.
Claim 25
Dependent Claim
66 words
The method as described in claim 22 further comprising the steps of: producing a correlation between said thickness and said phase error; providing a second reticle having a second reticle phase-shifted feature; measuring a second reticle thickness of said second reticle phase-shifted feature; and, determining a second reticle phase error by comparing said second reticle thickness to said correlation between said thickness and said phase error.
Claim 26
Dependent Claim
85 words
The method as described in claim 22 wherein each of said plurality of first features comprises a first reticle dimension corresponding to said first dimension of said first image, said second feature comprises a second reticle dimension corresponding to said second dimension of said second image, and each of said plurality of third features comprises a third reticle dimension corresponding to said third dimension of said third image, wherein said first reticle dimension, said second reticle dimension, and said third reticle dimension are approximately equal.
Claim 27
Dependent Claim
85 words
The method as described in claim 21 wherein each of said plurality of first features comprises a first reticle dimension corresponding to said first dimension of said first image, said second feature comprises a second reticle dimension corresponding to said second dimension of said second image, and each of said plurality of third features comprises a third reticle dimension corresponding to said third dimension of said third image, wherein said first reticle dimension, said second reticle dimension, and said third reticle dimension are approximately equal.
Claim 28
Dependent Claim
85 words
The method as described in claim 20 wherein each of said plurality of first features comprises a first reticle dimension corresponding to said first dimension of said first image, said second feature comprises a second reticle dimension corresponding to said second dimension of said second image, and each of said plurality of third features comprises a third reticle dimension corresponding to said third dimension of said third image, wherein said first reticle dimension, said second reticle dimension, and said third reticle dimension are approximately equal.
Claim 29
Dependent Claim
85 words
The method as described in claim 18 wherein each of said plurality of first features comprises a first reticle dimension corresponding to said first dimension of said first image, said second feature comprises a second reticle dimension corresponding to said second dimension of said second image, and each of said plurality of third features comprises a third reticle dimension corresponding to said third dimension of said third image, wherein said first reticle dimension, said second reticle dimension, and said third reticle dimension are approximately equal.
Claim 30
Dependent Claim
95 words
The method as described in claim 17 wherein said first dimension of said first feature is measured at a plurality of focal distances to form a first dimension versus focal distance relationship for said first feature, wherein said second dimension of said second feature is measured at said plurality of focal distances to form a second dimension versus focal distance relationship for said second feature, and wherein said third dimension of said third feature is measured at said plurality of focal distances to form a third dimension versus focal distance relationship for said third feature.
Claim 31
Dependent Claim
77 words
The method as described in claim 17 wherein said first feature comprises a first reticle dimension corresponding to said first dimension of said first image, said second feature comprises a second reticle dimension corresponding to said second dimension of said second image, and said third feature comprises a third reticle dimension corresponding to said third dimension of said third image, wherein said first reticle dimension, said second reticle dimension, and said third reticle dimension are approximately equal.
Claim 32
Independent Claim
101 words
A method of determining phase error in a phase-shifted reticle comprising the steps of: providing on said reticle a first feature, said first feature being a phase-shifted feature; providing on said reticle a second feature, said second feature being a phase-shifted feature, wherein said phase-shift of said first feature is in an opposite direction of said phase-shift of said second feature; measuring a first dimension of a first image of said first feature and a second dimension of a second image of said second feature; and determining said phase-shift based upon a comparison of said first dimension and said second dimension.
Claim 33
Independent Claim
101 words
A method of determining phase error in a phase-shifted reticle comprising the steps of: providing on said reticle a first feature, said first feature being a phase-shifted feature; providing on said reticle a second feature, said second feature being a phase-shifted feature, wherein said phase-shift of said first feature is in an opposite direction of said phase-shift of said second feature; measuring a first dimension of a first image of said first feature and a second dimension of a second image of said second feature; and determining said phase-shift based upon a comparison of said first dimension and said second dimension.
Claim 34
Dependent Claim
108 words
The method as described in claim 30 wherein a plurality of sets of said first features and said second features are provided on said reticle, wherein the magnitude of said phase-shift of said first feature and said second feature in each of said plurality of sets is approximately equal, and wherein the magnitude of said phase-shift of at least one of said sets is different from the magnitude of said phase-shift of another of said sets, and wherein said method further comprises the step of measuring said first dimension of said first image and said second dimension of said second image for each of said plurality of sets.
Claim 35
Dependent Claim
87 words
The method as described in claim 31 wherein said first dimension of said first feature is measured at a plurality of focal distances for each of said plurality of first features to form a first dimension versus focal distance relationship for each of said first features, and wherein said second dimension of said second feature is measured at said plurality of focal distances for each of said plurality of said second features to form a second dimension versus focal distance relationship for each of said second features.
Claim 36
Dependent Claim
33 words
The method as described in claim 32 wherein a focal shift is determined for each of said first dimension versus focal distance relationships by reference to said second dimension versus focal distance relationship.
Claim 37
Dependent Claim
20 words
The method as described in claim 33 wherein said method further comprises determining a focal shift versus phase error relationship.
Claim 38
Dependent Claim
104 words
The method as described in claim 34 wherein said phase-shift of said plurality of first features is created by a thickness of a material, and wherein said step of determining said focal shift versus phase error relationship is determined by: correlating said focal shift of each of said first features with said thickness of each of said first features; determining a zero phase error thickness value; and, determining phase error for each of said plurality of first features by comparing said thickness of each of said first features to said zero phase error thickness value to produce said focal shift versus phase error relationship.
Claim 39
Dependent Claim
66 words
The method as described in claim 35 further comprising the steps of: producing a correlation between said thickness and said phase error; providing a second reticle having a second reticle phase-shifted feature; measuring a second reticle thickness of said second reticle phase-shifted feature; and, determining a second reticle phase error by comparing said second reticle thickness to said correlation between said thickness and said phase error.
Claim 40
Dependent Claim
134 words
The method as described in claim 34 further comprising the steps of: providing a second reticle having said first feature and said second feature; measuring said first dimension of said first feature and said second dimension of said second feature on said second reticle at plurality of focal distances to form a second reticle first dimension versus focal distance relationship for said first feature on said second reticle and a second reticle second dimension versus focal distance relationship for said second feature on said second reticle; determining a focal shift of said first feature by comparing said second reticle first dimension versus focal distance relationship to said second reticle second dimension versus focal distance relationship; and, determining a phase error of said second reticle by comparison to said focal shift versus phase error relationship.
Claim 41
Dependent Claim
64 words
The method as described in claim 34 wherein each of said plurality of first features comprises a first reticle dimension corresponding to said first dimension of said first image, and each of said plurality of second features comprises a second reticle dimension corresponding to said second dimension of said second image, wherein said first reticle dimension and said second reticle dimension are approximately equal.
Claim 42
Dependent Claim
64 words
The method as described in claim 33 wherein each of said plurality of first features comprises a first reticle dimension corresponding to said first dimension of said first image, and each of said plurality of second features comprises a second reticle dimension corresponding to said second dimension of said second image, wherein said first reticle dimension and said second reticle dimension are approximately equal.
Claim 43
Dependent Claim
64 words
The method as described in claim 31 wherein each of said plurality of first features comprises a first reticle dimension corresponding to said first dimension of said first image, and each of said plurality of second features comprises a second reticle dimension corresponding to said second dimension of said second image, wherein said first reticle dimension and said second reticle dimension are approximately equal.
Claim 44
Dependent Claim
66 words
The method as described in claim 30 wherein said first dimension of said first feature is measured at a plurality of focal distances to form a first dimension versus focal distance relationship for said first feature, and wherein said second dimension of said second feature is measured at said plurality of focal distances to form a second dimension versus focal distance relationship for said second feature.
Claim 45
Dependent Claim
56 words
The method as described in claim 30 wherein said first feature comprises a first reticle dimension corresponding to said first dimension of said first image, and said second feature comprises a second reticle dimension corresponding to said second dimension of said second image, wherein said first reticle dimension and said second reticle dimension are approximately equal.
Claim 46
Dependent Claim
33 words
A phase-shifted reticle comprising a metrology pattern, said metrology pattern comprising: a first feature, said first feature being a phase-shifted feature; and, a second feature, said second feature being a non phase-shifted feature.
Claim 47
Dependent Claim
33 words
A phase-shifted reticle comprising a metrology pattern, said metrology pattern comprising: a first feature, said first feature being a phase-shifted feature; and, a second feature, said second feature being a non phase-shifted feature.
Claim 48
Dependent Claim
20 words
The reticle as described in claim 43 wherein said first feature and said second feature have an approximately equal dimension.
Claim 49
Dependent Claim
38 words
The reticle as described in claim 44 further comprising a third feature, said third feature being a phase-shifted feature, wherein said phase-shift of said third feature is in an opposite direction of said phase-shift of said first feature.
Claim 50
Dependent Claim
38 words
The reticle as described in claim 43 further comprising a third feature, said third feature being a phase-shifted feature, wherein said phase-shift of said third feature is in an opposite direction of said phase-shift of said first feature.
Claim 51
Dependent Claim
51 words
A phase-shifted reticle comprising a metrology feature, said metrology feature comprising: a first feature, said first feature, being a phase-shifted feature; and, a second feature, said second feature being a phase-shifted feature wherein said phase-shift of said first feature is in an opposite direction of said phase-shift of said second feature.
Claim 52
Dependent Claim
51 words
A phase-shifted reticle comprising a metrology feature, said metrology feature comprising: a first feature, said first feature, being a phase-shifted feature; and, a second feature, said second feature being a phase-shifted feature wherein said phase-shift of said first feature is in an opposite direction of said phase-shift of said second feature.
Claim 53
Dependent Claim
20 words
The reticle as described in claim 47 wherein said first feature and said second feature have an approximately equal dimension.
Claim 54
Dependent Claim
70 words
A phase-shifted reticle comprising: a plurality of first features, wherein said plurality of first features are phase-shifted features having a first feature phase-shift, and wherein the magnitude of said first feature phase-shift of one of said plurality of first features is different from the magnitude of said first feature phase-shift for another of said plurality of first features; and, a second feature, said second feature being a non phase-shifted feature.
Claim 55
Dependent Claim
70 words
A phase-shifted reticle comprising: a plurality of first features, wherein said plurality of first features are phase-shifted features having a first feature phase-shift, and wherein the magnitude of said first feature phase-shift of one of said plurality of first features is different from the magnitude of said first feature phase-shift for another of said plurality of first features; and, a second feature, said second feature being a non phase-shifted feature.
Claim 56
Dependent Claim
109 words
The reticle as described in claim 49 further comprising: a plurality of third features, wherein said plurality of third features are phase-shifted features having a second feature phase-shift, and wherein said first feature phase-shift is in an opposite direction of said third feature phase-shift, and wherein the magnitude of said third feature phase-shift for one of said plurality of third features is approximately equal to that of said one of said plurality of said first features, and wherein the magnitude of said third feature phase-shift for another of said plurality of said second features is approximately equal to that of said another of said plurality of said first features.
Claim 57
Dependent Claim
159 words
A phase-shifted reticle comprising: a plurality of first features, wherein said plurality of first features are phase-shifted features having a first feature phase-shift, and wherein the magnitude of said first feature phase-shift of one of said plurality of first features is different from the magnitude of said first feature phase-shift for another of said plurality of first features; and, a plurality of second features, wherein said plurality of second features are phase-shifted features having a second feature phase-shift, and wherein said first feature phase-shift is in an opposite direction of said second feature phase-shift and wherein the magnitude of said second feature phase-shift for one of said plurality of second features is approximately equal to that of said one of said plurality of said first features and wherein the magnitude of said second feature phase-shift for another of said plurality of said second features is approximately equal to that of said another of said plurality of said first features.
Claim 58
Dependent Claim
159 words
A phase-shifted reticle comprising: a plurality of first features, wherein said plurality of first features are phase-shifted features having a first feature phase-shift, and wherein the magnitude of said first feature phase-shift of one of said plurality of first features is different from the magnitude of said first feature phase-shift for another of said plurality of first features; and, a plurality of second features, wherein said plurality of second features are phase-shifted features having a second feature phase-shift, and wherein said first feature phase-shift is in an opposite direction of said second feature phase-shift and wherein the magnitude of said second feature phase-shift for one of said plurality of second features is approximately equal to that of said one of said plurality of said first features and wherein the magnitude of said second feature phase-shift for another of said plurality of said second features is approximately equal to that of said another of said plurality of said first features.
References Cited (Backward Citations)
US4360586A
Cited
US4231811A
Cited
EP0090924A2
Cited
US4881257A
Cited
US4890309A
Cited
US5045417A
Cited
EP0395425A2
Cited
US5049925A
Cited
WO1991020018A1
Cited
US5135609A
Cited
EP0492630A2
Cited
US5229255A
Cited
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| 3.5 Years (Year 4) | 2000-12-22 | 2001-06-23 | 2001-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-12-22 | 2005-06-23 | 2005-12-23 | $3760.00 | Window Closed / Lapsed |
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