US6373553B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photo-lithographic method to print a line-space pattern with a pitch equal to half the pitch of the mask
Assignee: Intel Corp
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Filing: 1999-09-20
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Granted: 2002-04-16
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Expires: 2019-09-20
Abstract
Abstract An optical lithography system and method which utilizes a mask pattern and forms Talbot sub-images of an illuminated grating onto a photosensitive target to print an image pattern on the photosensitive target such that the image pattern printed has a pitch equal to half the pitch of the mask pattern.
Inventors
- 👤 Vivek K. Singh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:23
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70408; G03F7/70216; G03F7/70325; G03F7/7035; G03F7/0005; G03F7/001
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
135 words
A lithography method, comprising the steps of: utilizing a mask having a mask pattern for printing an image pattern; and forming Talbot sub-images of an illuminated grating on a photosensitive target to print said image pattern on the photosensitive target such that said image pattern printed has a pitch equal to half the pitch of the mask pattern, wherein said Talbot sub-images on the photosensitive target are formed by moving the photosensitive target away from an image plane by a Talbot distance obtained, during exposure of a light beam onto the photosensitive target via said mask, through one of a grating equation of L 2 /2λ where L represents the pitch of the mask pattern and λ represents a wavelength of the light beam selected for optical lithography, and the use of a lithography simulator.
Claim 2
Dependent Claim
135 words
A lithography method, comprising the steps of: utilizing a mask having a mask pattern for printing an image pattern; and forming Talbot sub-images of an illuminated grating on a photosensitive target to print said image pattern on the photosensitive target such that said image pattern printed has a pitch equal to half the pitch of the mask pattern, wherein said Talbot sub-images on the photosensitive target are formed by moving the photosensitive target away from an image plane by a Talbot distance obtained, during exposure of a light beam onto the photosensitive target via said mask, through one of a grating equation of L 2 /2λ where L represents the pitch of the mask pattern and λ represents a wavelength of the light beam selected for optical lithography, and the use of a lithography simulator.
Claim 3
Dependent Claim
37 words
The method as claimed in claim 1 , wherein said light beam corresponds to a source of partially coherent light having a wavelength selected for optical lithography, and said image pattern corresponds to a nested line-space pattern.
Claim 4
Dependent Claim
36 words
The method as claimed in claim 1 , further comprising a step of depositing a resist layer on said photosensitive target for forming said image pattern thereon upon exposure of said light beam via said mask.
Claim 5
Dependent Claim
36 words
The method as claimed in claim 3 , further comprising a step of forming an anti-reflective coating on said photosensitive layer underneath said resist layer with a refractive index matched to that of said resist layer.
Claim 6
Dependent Claim
36 words
The method as claimed in claim 3 , further comprising a step of optimizing said resist layer by post exposure bake to reduce tilt of resist lines after exposure of said light beam via said mask.
Claim 7
Dependent Claim
39 words
The method as claimed in claim 1 , further comprising a step of exposing a light beam from a source of partially coherent light having a wavelength selected for optical lithography via said mask to form said image pattern.
Claim 8
Dependent Claim
38 words
The method as claimed in claim 1 , wherein said mask has a 100 nm line in a pitch of 200 nm, and said image pattern printed has a 50 nm line in a pitch of 100 nm.
Claim 9
Independent Claim
107 words
A method of forming an image, comprising: forming an image pattern of a first pitch on an image plane of a target by illumination via a mask having a mask pattern of said first pitch; and forming a Talbot image pattern of a second pitch on the target by moving the target away from the image plane of the target by a Talbot distance obtained, during said illumination, through one of a grating equation of L 2 /2λ where L represents the pitch of the mask pattern and λ represents a wavelength of a light beam selected for optical lithography, and the use of a lithography simulator.
Claim 10
Independent Claim
107 words
A method of forming an image, comprising: forming an image pattern of a first pitch on an image plane of a target by illumination via a mask having a mask pattern of said first pitch; and forming a Talbot image pattern of a second pitch on the target by moving the target away from the image plane of the target by a Talbot distance obtained, during said illumination, through one of a grating equation of L 2 /2λ where L represents the pitch of the mask pattern and λ represents a wavelength of a light beam selected for optical lithography, and the use of a lithography simulator.
Claim 11
Dependent Claim
34 words
The method as claimed in claim 8 , wherein said step of forming a Talbot image pattern is performed by using said image pattern of said first pitch twice greater than said second pitch.
Claim 12
Dependent Claim
39 words
The method as claimed in claim 8 , further comprising: printing said Talbot image pattern of said second pitch on the target after the target is moved away from the image plane of the target by said Talbot distance.
Claim 13
Dependent Claim
44 words
The method as claimed in claim 8 , further comprising a step of exposing a light source of partially coherent light having a wavelength selected for optical lithography during said illumination to form said Talbot image pattern of said second pitch on the target.
Claim 14
Dependent Claim
30 words
The method as claimed in claim 8 , further comprising a step of forming a resist layer on the target for forming said Talbot image pattern thereon upon said illumination.
Claim 15
Dependent Claim
34 words
The method as claimed in claim 12 , further comprising a step of forming an anti-reflective on the target underneath said resist layer with a refractive index matched to that of said resist layer.
Claim 16
Dependent Claim
30 words
The method as claimed in claim 12 , further comprising a step of optimizing said resist layer by post exposure bake to reduce tilt of resist lines after said illumination.
Claim 17
Dependent Claim
49 words
The method as claimed in claim 8 , further comprising a step of exposing a light source of partially coherent light having a wavelength selected for optical lithography via said mask to form said image pattern of said first pitch and said Talbot image pattern of said second pitch.
Claim 18
Dependent Claim
39 words
The method as claimed in claim 8 , wherein said mask pattern has a 100 nm line in a pitch of 200 nm, and said image pattern printed has a 50 nm line in a pitch of 100 nm.
Claim 19
Dependent Claim
130 words
A lithography system, comprising: a radiation source; a mask having a mask pattern positioned between the radiation source and a target; and means for forming Talbot sub-images of an illuminated grating onto the target to print an image pattern on the target such that said image pattern printed has a pitch equal to half the pitch of the mask pattern, wherein said Talbot sub-images on the target are formed by moving the target away from an image plane by a Talbot distance obtained, during exposure of the radiation source onto the target via said mask, through one of a grating equation of L 2 /2λ where L represents the pitch of the mask pattern and λ represents a wavelength of the radiation source, and the use of a lithography simulator.
Claim 20
Dependent Claim
130 words
A lithography system, comprising: a radiation source; a mask having a mask pattern positioned between the radiation source and a target; and means for forming Talbot sub-images of an illuminated grating onto the target to print an image pattern on the target such that said image pattern printed has a pitch equal to half the pitch of the mask pattern, wherein said Talbot sub-images on the target are formed by moving the target away from an image plane by a Talbot distance obtained, during exposure of the radiation source onto the target via said mask, through one of a grating equation of L 2 /2λ where L represents the pitch of the mask pattern and λ represents a wavelength of the radiation source, and the use of a lithography simulator.
Claim 21
Dependent Claim
36 words
The system as claimed in claim 17 , wherein said radiation source is a source of partially coherent light having a wavelength selected for optical lithography, and said image pattern corresponds to a nested line-space pattern.
Claim 22
Dependent Claim
37 words
The system as claimed in claim 17 , wherein said target corresponds to a semiconductor substrate having a resist layer deposited for forming said image pattern thereon upon exposure of said radiation source via said mask pattern.
Claim 23
Dependent Claim
32 words
The system as claimed in claim 19 , wherein said semiconductor substrate includes an anti-reflective coating formed underneath said resist layer with a refractive index matched to that of said resist layer.
Claim 24
Dependent Claim
24 words
The system as claimed in claim 20 , wherein said resist layer is optimized by post exposure bake to reduce tilt of resist lines.
Claim 25
Dependent Claim
26 words
The system as claimed in claim 17 , wherein said radiation source is a source of partially coherent light having a wavelength selected for optical lithography.
Claim 26
Dependent Claim
29 words
The system as claimed in claim 17 , wherein said target is moved away from the image plane of said target by said Talbot distance by a moving mechanism.
Claim 27
Dependent Claim
39 words
The system as claimed in claim 17 , wherein said mask pattern has a 100 nm line in a pitch of 200 nm, and said image pattern printed has a 50 nm line in a pitch of 100 nm.
Claim 28
Dependent Claim
128 words
A lithography system, comprising: a radiation source; a mask having a mask pattern positioned between the radiation source and a target; and a moving mechanism which moves the target away from an image plane to form Talbot sub-images of an illuminated grating onto the target by a Talbot distance obtained, during exposure of the radiation source onto the target via said mask, through one of a grating equation of L 2 /2λ where L represents the pitch of the mask pattern and λ represents a wavelength of the radiation source selected for optical lithography, and the use of a lithography simulator, for printing print an image pattern on the target such that said image pattern printed has a pitch equal to half the pitch of the mask pattern.
Claim 29
Dependent Claim
128 words
A lithography system, comprising: a radiation source; a mask having a mask pattern positioned between the radiation source and a target; and a moving mechanism which moves the target away from an image plane to form Talbot sub-images of an illuminated grating onto the target by a Talbot distance obtained, during exposure of the radiation source onto the target via said mask, through one of a grating equation of L 2 /2λ where L represents the pitch of the mask pattern and λ represents a wavelength of the radiation source selected for optical lithography, and the use of a lithography simulator, for printing print an image pattern on the target such that said image pattern printed has a pitch equal to half the pitch of the mask pattern.
Claim 30
Dependent Claim
36 words
The system as claimed in claim 25 , wherein said radiation source is a source of partially coherent light having a wavelength selected for optical lithography, and said image pattern corresponds to a nested line-space pattern.
Claim 31
Dependent Claim
37 words
The system as claimed in claim 25 , wherein said target corresponds to a semiconductor substrate having a resist layer deposited for forming said image pattern thereon upon exposure of said radiation source via said mask pattern.
Claim 32
Dependent Claim
32 words
The system as claimed in claim 27 , wherein said semiconductor substrate includes an anti-reflective coating formed underneath said resist layer with a refractive index matched to that of said resist layer.
Claim 33
Dependent Claim
24 words
The system as claimed in claim 28 , wherein said resist layer is optimized by post exposure bake to reduce tilt of resist lines.
Claim 34
Dependent Claim
26 words
The system as claimed in claim 25 , wherein said radiation source is a source of partially coherent light having a wavelength selected for optical lithography.
Claim 35
Dependent Claim
29 words
The system as claimed in claim 25 , wherein said target is moved away from the image plane of said target by said Talbot distance by a moving mechanism.
Claim 36
Dependent Claim
39 words
The system as claimed in claim 25 , wherein said mask pattern has a 100 nm line in a pitch of 200 nm, and said image pattern printed has a 50 nm line in a pitch of 100 nm.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-04-15 | 2005-10-15 | 2006-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-04-15 | 2009-10-15 | 2010-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-04-15 | 2013-10-15 | 2014-04-16 | $7700.00 | Window Closed / Lapsed |