US6451490B1
Expired / Lapsed
US
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Method to overcome image shortening by use of sub-resolution reticle features
Assignee: GlobalFoundries Inc
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Filing: 2000-11-08
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Granted: 2002-09-17
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Expires: 2020-11-08
Abstract
Abstract Image shortening in a photolithographic process is substantially reduced by using sub-resolution reticle features to alter the aerial image in the shortened regions. The use of such sub-resolution reticle features is simple to implement in a design system, and allows for increased feature aspect ratio as well as overlap to other critical features.
Inventors
- 👤 William H. Advocate
- 👤 Scott J. Bukofsky
- 👤 Christopher Adam Feild
- 👤 Donald J. Samuels
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:50
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/36; G03F1/26; G03F1/30; G03F7/00; G03F7/70; G03F7/70425; G03F7/70433; G03F1/32
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
69 words
A method for substantially reducing image shortening of printed dense array patterns comprising the steps of: (a) providing a mask having a dense array pattern formed thereon; and (b) adding at least one sub-resolution reticle feature perpendicular to at least one feature of said dense array pattern, wherein each of said sub-resolution reticle features have a width smaller than the at least one feature of said dense array pattern.
Claim 2
Independent Claim
69 words
A method for substantially reducing image shortening of printed dense array patterns comprising the steps of: (a) providing a mask having a dense array pattern formed thereon; and (b) adding at least one sub-resolution reticle feature perpendicular to at least one feature of said dense array pattern, wherein each of said sub-resolution reticle features have a width smaller than the at least one feature of said dense array pattern.
Claim 3
Dependent Claim
22 words
The method of claim 1 wherein said mask is comprised of an opaque material on quartz or an attenuating phase shift material.
Claim 4
Dependent Claim
19 words
The method of claim 1 wherein said mask is comprised, of phase-shifted regions in an alternating phase shift mask.
Claim 5
Dependent Claim
17 words
The method of claim 1 wherein said features of said dense array patterns are rectangular in shape.
Claim 6
Dependent Claim
14 words
The method of claim 1 wherein said sub-resolution reticle features are rectangular in shape.
Claim 7
Dependent Claim
17 words
The method of claim 1 wherein both of said features are clear features on an opaque background.
Claim 8
Dependent Claim
17 words
The method of claim 1 wherein both of said features are opaque features on a clear background.
Claim 9
Dependent Claim
23 words
The method of claim 1 wherein said at least one sub-resolution feature is formed from phase-shifted regions in an alternating phase shifted mask.
Claim 10
Dependent Claim
24 words
The method of claim 1 wherein said added sub-resolution reticle features are attached to the at least one feature of said dense array pattern.
Claim 11
Dependent Claim
27 words
The method of claim 1 wherein said added sub- resolution reticle features are formed in spaces between said at least one feature of said dense array pattern.
Claim 12
Dependent Claim
18 words
The method of claim 1 further comprising employing said mask in an exposure step of a photolithography process.
Claim 13
Dependent Claim
53 words
A photomask comprising a dense array pattern formed on a surface of a mask and at least one sub-resolution reticle feature located perpendicular to at least one feature of said dense array pattern, wherein each sub-resolution reticle feature has a width smaller than the at least one feature of said dense array pattern.
Claim 14
Dependent Claim
53 words
A photomask comprising a dense array pattern formed on a surface of a mask and at least one sub-resolution reticle feature located perpendicular to at least one feature of said dense array pattern, wherein each sub-resolution reticle feature has a width smaller than the at least one feature of said dense array pattern.
Claim 15
Dependent Claim
22 words
The photomask of claim 12 wherein said mask is comprised of an opaque material on quartz or an attenuating phase shift material.
Claim 16
Dependent Claim
19 words
The photomask of claim 12 wherein said mask is comprised of phase-shifted regions in an alternating phase shift mask.
Claim 17
Dependent Claim
17 words
The photomask of claim 12 wherein said features of said dense array patterns are rectangular in shape.
Claim 18
Dependent Claim
14 words
The photomask of claim 12 wherein said sub-resolution reticle features are rectangular in shape.
Claim 19
Dependent Claim
17 words
The photomask of claim 12 wherein both of said features are clear features on an opaque background.
Claim 20
Dependent Claim
17 words
The photomask of claim 12 wherein both of said features are opaque features on a clear background.
Claim 21
Dependent Claim
23 words
The photomask of claim 12 wherein said at least one sub-resolution feature is formed from phase-shifted regions in an alternating phase shift mask.
Claim 22
Dependent Claim
24 words
The photomask of claim 12 wherein said added sub-resolution reticle features are attached to the at least one feature of said dense array pattern.
Claim 23
Dependent Claim
26 words
The photomask of claim 12 wherein said added sub-resolution reticle features are formed in spaces between said at least one feature of said dense array pattern.
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) | 2005-09-16 | 2006-03-18 | 2006-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-09-16 | 2010-03-18 | 2010-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-09-16 | 2014-03-18 | 2014-09-17 | $7700.00 | Window Closed / Lapsed |