US5300379A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of fabrication of inverted phase-shifted reticle
Assignee: Intel Corp
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Filing: 1992-08-21
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Granted: 1994-04-05
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Expires: 2012-08-21
Abstract
Abstract A phase-shifted reticle with patterns proximate each other having inverted phases for the features and phase-shifting elements, and methods of fabricating the reticle, are disclosed. In a preferred embodiment, the inverted reticle is used to form an array of closely spaced contact or via openings. For a first pattern on the reticle, the feature will be the 0° phase and the phase-shifting rim surrounding that feature will be the 180° phase. All patterns surrounding the first pattern have phase-shifting rims of the 0° phase and features of the 180° phase. In this way, each pattern can form below conventional resolution features in the resist. Additionally, there will not be exposure of the regions between the closely spaced features since radiation transmitted through the closely spaced phase-shifting rims of the two patterns is 180° out of phase.
Inventors
- 👤 Giang T. Dao
- 👤 Eng T. Gaw
- 👤 Nelson N. Tam
- 👤 Ruben A. Rodriquez
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:13
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: 31
Claim 1
Independent Claim
190 words
A method of fabricating a phase-shifted reticle for use on a printer having a numerical aperture (NA), an image reduction factor (IRF) and an exposing radiation wavelength (λ), comprising the steps of: a) providing a substrate with an opaque layer formed thereon, said substrate with said opaque layer having a first region, a second region, a third region and a fourth region, wherein said second region is proximate and between said first and said third regions, and said third region is proximate said fourth region, wherein said second region comprises a phase-shifting element for said first region and said third region comprises a phase-shifting element for said fourth region, and wherein said third region is disposed within approximately 0.55 IRF* λ/NA of said second region; b) removing said opaque layer from said first and said third regions; c) removing a thickness of said substrate from said first region, said thickness sufficient to shift the phase of radiation in the range of approximately 160 through 200 degrees; d) removing said thickness of said substrate from said third region; and, e) removing said opaque layer from said second and said fourth regions.
Claim 2
Independent Claim
190 words
A method of fabricating a phase-shifted reticle for use on a printer having a numerical aperture (NA), an image reduction factor (IRF) and an exposing radiation wavelength (λ), comprising the steps of: a) providing a substrate with an opaque layer formed thereon, said substrate with said opaque layer having a first region, a second region, a third region and a fourth region, wherein said second region is proximate and between said first and said third regions, and said third region is proximate said fourth region, wherein said second region comprises a phase-shifting element for said first region and said third region comprises a phase-shifting element for said fourth region, and wherein said third region is disposed within approximately 0.55 IRF* λ/NA of said second region; b) removing said opaque layer from said first and said third regions; c) removing a thickness of said substrate from said first region, said thickness sufficient to shift the phase of radiation in the range of approximately 160 through 200 degrees; d) removing said thickness of said substrate from said third region; and, e) removing said opaque layer from said second and said fourth regions.
Claim 3
Dependent Claim
103 words
The method as described in claim 1 wherein said steps b, c, d, and e are performed by: providing a first patterning layer; forming first openings in said first patterning layer to expose said first and said third regions; etching said opaque layer in said first and said third regions; etching said substrate in said first and said third regions; removing said first patterning layer; providing a second patterning layer; forming second openings in said second patterning layer to expose said second and said fourth regions; etching said opaque layer in said second and said fourth regions; and, removing said second patterning layer.
Claim 4
Dependent Claim
50 words
The method as described in claim 2 wherein said second region surrounds said first region, said fourth region surrounds said third region, wherein said first and second regions form a first opening pattern and said third and said fourth regions form a second opening pattern proximate said first opening pattern.
Claim 5
Dependent Claim
27 words
The method as described in claim 1 wherein said second region is adjacent to said first region, and said fourth region is adjacent to said third region.
Claim 6
Dependent Claim
51 words
The method as described in claim 4 wherein said second region surrounds said first region, said fourth region surrounds said third region, and wherein said first and second regions form a first opening pattern and said third and said fourth regions form a second opening pattern proximate said first opening pattern.
Claim 7
Dependent Claim
24 words
The method as described in claim 1 wherein said steps b and e are performed simultaneously and prior to said steps c and d.
Claim 8
Dependent Claim
100 words
The method as described in claim 6 wherein said steps b, c, d, and e are performed by: providing a first patterning layer; forming first openings in said first patterning layer to expose said first, said second, said third, and said fourth regions; etching said opaque layer in said first, said second, said third, and said fourth regions; removing said first patterning layer; providing a second patterning layer; forming second openings in said second patterning layer to expose said first and said third regions; etching said substrate in said first and said third regions; and, removing said second patterning layer.
Claim 9
Dependent Claim
50 words
The method as described in claim 7 wherein said second region surrounds said first region, said fourth region surrounds said third region, wherein said first and second regions form a first opening pattern and said third and said fourth regions form a second opening pattern proximate said first opening pattern.
Claim 10
Dependent Claim
51 words
The method as described in claim 6 wherein said second region surrounds said first region, said fourth region surrounds said third region, and wherein said first and second regions form a first opening pattern and said third and said fourth regions form a second opening pattern proximate said first opening pattern.
Claim 11
Independent Claim
201 words
A method of fabricating a phase-shifted reticle for use on a printer having a numerical aperture (NA), an image reduction factor (IRF) and an exposing radiation wavelength (λ), comprising the steps of: a) providing a substrate with an opaque layer formed thereon, said substrate with said opaque layer having a first region, a second region, a third region and a fourth region, wherein said second region is proximate and between said first and said third regions, and said third region is proximate said fourth region, wherein said second region comprsies a phase-shifting element for said first region and said third region comprises a phase-shifting element for said fourth region, and wherein said third region is disposed within approximately 0.55 IRF*λ/NA of said second region; b) removing said opaque layer from said second and said third regions; c) removing a thickness of said substrate from said second region, said thickness sufficient to shift the phase of radiation in the range of approximately 160-200 degrees; d) removing said thickness of said substrate from said third region; e) removing said opaque layer from said first and said fourth regions; and, f) removing said thickness of said substrate from said first and said second regions.
Claim 12
Independent Claim
201 words
A method of fabricating a phase-shifted reticle for use on a printer having a numerical aperture (NA), an image reduction factor (IRF) and an exposing radiation wavelength (λ), comprising the steps of: a) providing a substrate with an opaque layer formed thereon, said substrate with said opaque layer having a first region, a second region, a third region and a fourth region, wherein said second region is proximate and between said first and said third regions, and said third region is proximate said fourth region, wherein said second region comprsies a phase-shifting element for said first region and said third region comprises a phase-shifting element for said fourth region, and wherein said third region is disposed within approximately 0.55 IRF*λ/NA of said second region; b) removing said opaque layer from said second and said third regions; c) removing a thickness of said substrate from said second region, said thickness sufficient to shift the phase of radiation in the range of approximately 160-200 degrees; d) removing said thickness of said substrate from said third region; e) removing said opaque layer from said first and said fourth regions; and, f) removing said thickness of said substrate from said first and said second regions.
Claim 13
Dependent Claim
141 words
The method as described in claim 10 wherein said steps b, c, d, e, and f are performed by: providing a first patterning layer; forming first openings in said first patterning layer to expose said second and said third regions; etching said opaque layer in said second and said third regions; etching said substrate in said second and said third regions; removing said first patterning layer; providing a second patterning layer; forming second openings in said second patterning layer to expose said first and said fourth regions; etching said opaque layer in said first and said fourth regions; removing said second patterning layer; providing a third patterning layer; forming a third opening in said third patterning layer to expose said first and said second regions; etching said substrate in said first and said second regions; and, removing said third patterning layer.
Claim 14
Dependent Claim
50 words
The method as described in claim 11 wherein said second region surrounds said first region, said fourth region surrounds said third region, wherein said first and second regions form a first opening pattern and said third and said fourth regions form a second opening pattern proximate said first opening pattern.
Claim 15
Dependent Claim
27 words
The method as described in claim 10 wherein said second region is adjacent to said first region, and said fourth region is adjacent to said third region.
Claim 16
Dependent Claim
51 words
The method as described in claim 13 wherein said second region surrounds said first region, said fourth region surrounds said third region, and wherein said first and second regions form a first opening pattern and said third and said fourth regions form a second opening pattern proximate said first opening pattern.
Claim 17
Independent Claim
231 words
A method of fabricating a phase-shifted reticle for use on a printer having a numerical aperture (NA), an image reduction factor (IRF) and an exposing radiation wavelength (λ), comprising the steps of: a) providing a substrate with an opaque layer formed thereon, said substrate with said opaque layer having a first region, a second region, a third region and a fourth region, wherein said second region is proximate and between said first and said third regions, and said third region is proximate said fourth region, wherein said second region comprises a phase-shifting element for said first region and said third region comprises a phase-shifting element for said fourth region, and wherein said third region is disposed within approximately 0.55 IRF*λ/NA of said second region; b) forming a sacrificial layer on said opaque layer and said substrate; c) removing said sacrificial layer from said second region and said fourth region; d) removing said opaque layer from said second region and said fourth region; e) removing a thickness of said substrate from said second region, said thickness sufficient to shift the phase of radiation in the range of approximately 160-200 degrees; f) removing said thickness of said substrate from said fourth region; g) removing said sacrificial layer and said opaque layer from said first region; h) removing said opaque layer from said third region; and, i) removing the remainder of said sacrificial layer.
Claim 18
Independent Claim
231 words
A method of fabricating a phase-shifted reticle for use on a printer having a numerical aperture (NA), an image reduction factor (IRF) and an exposing radiation wavelength (λ), comprising the steps of: a) providing a substrate with an opaque layer formed thereon, said substrate with said opaque layer having a first region, a second region, a third region and a fourth region, wherein said second region is proximate and between said first and said third regions, and said third region is proximate said fourth region, wherein said second region comprises a phase-shifting element for said first region and said third region comprises a phase-shifting element for said fourth region, and wherein said third region is disposed within approximately 0.55 IRF*λ/NA of said second region; b) forming a sacrificial layer on said opaque layer and said substrate; c) removing said sacrificial layer from said second region and said fourth region; d) removing said opaque layer from said second region and said fourth region; e) removing a thickness of said substrate from said second region, said thickness sufficient to shift the phase of radiation in the range of approximately 160-200 degrees; f) removing said thickness of said substrate from said fourth region; g) removing said sacrificial layer and said opaque layer from said first region; h) removing said opaque layer from said third region; and, i) removing the remainder of said sacrificial layer.
Claim 19
Dependent Claim
158 words
The method as described in claim 15 wherein said steps c, d, e, f, g, and h are performed by: providing a first patterning layer; forming first openings in said first patterning layer to expose said second and said fourth regions; etching said sacrificial layer in said second and said fourth regions; etching said opaque layer in said second and said fourth regions; etching said substrate in said second and said fourth regions; removing said first patterning layer; providing a second patterning layer; forming second openings in said second patterning layer to expose said first region; etching said sacrificial layer in said first region; etching said opaque layer in said first region; removing said second patterning layer; providing a third patterning layer; forming a third opening in said third patterning layer to expose said second and said third regions; etching said opaque layer in said second region by performing an undercut etch; and, removing said third patterning layer.
Claim 20
Dependent Claim
50 words
The method as described in claim 16 wherein said second region surrounds said first region, said fourth region surrounds said third region, wherein said first and second regions form a first opening pattern and said third and said fourth regions form a second opening pattern proximate said first opening pattern.
Claim 21
Dependent Claim
27 words
The method as described in claim 15 wherein said second region is adjacent to said first region, and said fourth region is adjacent to said third region.
Claim 22
Dependent Claim
51 words
The method as described in claim 18 wherein said second region surrounds said first region, said fourth region surrounds said third region, and wherein said first and second regions form a first opening pattern and said third and said fourth regions form a second opening pattern proximate said first opening pattern.
Claim 23
Independent Claim
193 words
A method of fabricating a phase-shifted reticle for use on a printer having a numerical aperture (NA), an image reduction factor (IRF) and an exposing radiation wavelength (λ), comprising the steps of: a) providing a substrate with an opaque layer formed thereon, said substrate with said opaque layer having a first region, a second region, a third region and a fourth region, wherein said second region is proximate and between said first and said third regions, and said third region is proximate said fourth region, wherein said second region comprises a phase-shifting element for said first region and said third region comprises a phase-shifting element for said fourth region, and wherein said third region is disposed within approximately 0.55 IRF*λ/NA of said second region; b) removing said opaque layer from said first, said second, said third, and said fourth regions; c) removing a thickness of said substrate from said first region, said thickness sufficient to shift the phase of radiation in the range of approximately 160-200 degrees; d) removing said thickness of said substrate from said fourth region; and, e) removing said thickness of said substrate from said first and said second regions.
Claim 24
Independent Claim
193 words
A method of fabricating a phase-shifted reticle for use on a printer having a numerical aperture (NA), an image reduction factor (IRF) and an exposing radiation wavelength (λ), comprising the steps of: a) providing a substrate with an opaque layer formed thereon, said substrate with said opaque layer having a first region, a second region, a third region and a fourth region, wherein said second region is proximate and between said first and said third regions, and said third region is proximate said fourth region, wherein said second region comprises a phase-shifting element for said first region and said third region comprises a phase-shifting element for said fourth region, and wherein said third region is disposed within approximately 0.55 IRF*λ/NA of said second region; b) removing said opaque layer from said first, said second, said third, and said fourth regions; c) removing a thickness of said substrate from said first region, said thickness sufficient to shift the phase of radiation in the range of approximately 160-200 degrees; d) removing said thickness of said substrate from said fourth region; and, e) removing said thickness of said substrate from said first and said second regions.
Claim 25
Dependent Claim
118 words
The method as described in claim 20 wherein said steps b, c, d, and e are performed by: providing a first patterning layer; forming first openings in said first patterning layer to expose said first and said fourth regions; etching said opaque layer in said first and said fourth regions; etching said opaque layer in said second and said third regions by performing an undercut etch; etching said substrate in said first and said fourth regions; removing said first patterning layer; providing a second patterning layer; forming second openings in said second patterning layer to expose said first and said second regions; etching said substrate in said first and said second regions; and, removing said second patterning layer.
Claim 26
Dependent Claim
50 words
The method as described in claim 21 wherein said second region surrounds said first region, said fourth region surrounds said third region, wherein said first and second regions form a first opening pattern and said third and said fourth regions form a second opening pattern proximate said first opening pattern.
Claim 27
Dependent Claim
27 words
The method as described in claim 20 wherein said second region is adjacent to said first region, and said fourth region is adjacent to said third region.
Claim 28
Dependent Claim
51 words
The method as described in claim 23 wherein said second region surrounds said first region, said fourth region surrounds said third region, and wherein said first and second regions form a first opening pattern and said third and said fourth regions form a second opening pattern proximate said first opening pattern.
Claim 29
Dependent Claim
136 words
The method as described in claim 20 wherein said steps b, c, d, and e are performed by: providing a first patterning layer; forming first openings in said first patterning layer to expose said first, said second, said third, and said fourth regions; etching said opaque layer in said first, said second, said third, and said fourth regions; removing said first patterning layer; providing a second patterning layer; forming second openings in said second patterning layer to expose said first and said fourth regions; etching said substrate in said first and said fourth regions; removing said second patterning layer; providing a third patterning layer; forming third openings in said third patterning layer to expose said first and said second regions; etching said substrate in said first and said second regions; and, removing said third patterning layer.
Claim 30
Dependent Claim
27 words
The method as described in claim 25 wherein said second region is adjacent to said first region, and said fourth region is adjacent to said third region.
Claim 31
Dependent Claim
51 words
The method as described in claim 26 wherein said second region surrounds said first region, said fourth region surrounds said third region, and wherein said first and second regions form a first opening pattern and said third and said fourth regions form a second opening pattern proximate said first opening pattern.
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