US5455131A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for fabrication of lithography mask
Assignee: SK Hynix Inc
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Filing: 1994-04-25
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Granted: 1995-10-03
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Expires: 2014-04-25
Abstract
Abstract This invention relates to a method for fabrication of masks suitable for improving semiconductor wafers in resolution, which comprises processes for depositing a phases shifting layer and an opaque layer on a transparent substrate, defining an opaque area and a transparent area and removing the opaque layer from the transparent area selectively, forming side wall on the sides of the opaque layer, and removing the exposed phase shifting layer selectively using the side walls and the opaque layer as a mask.
Inventors
- 👤 Chan H. Kang
- 👤 Jun S. Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:04
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/26; G03F1/29
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
75 words
A method for fabricating a lithography mask, comprising the steps of: depositing a phase shifting layer on a transparent substrate; depositing an opaque layer on the phase shifting layer; defining an opaque area and a transparent area and selectively removing the opaque layer from the transparent area; forming sidewall spacers of sidewalls of the opaque layer; and using the sidewall spacers and the opaque layer as a mask, selectively removing the exposed phase shifting layer.
Claim 2
Independent Claim
75 words
A method for fabricating a lithography mask, comprising the steps of: depositing a phase shifting layer on a transparent substrate; depositing an opaque layer on the phase shifting layer; defining an opaque area and a transparent area and selectively removing the opaque layer from the transparent area; forming sidewall spacers of sidewalls of the opaque layer; and using the sidewall spacers and the opaque layer as a mask, selectively removing the exposed phase shifting layer.
Claim 3
Dependent Claim
24 words
The method as claimed in claim 1 wherein said opaque layer removing step and said phase shifting layer removing step both include vertical etching.
Claim 4
Dependent Claim
34 words
The method as claimed in claim 1 wherein the sidewall spacers are formed as the mask so as to obtain a pattern of the phase shifting layer which is wider than the opaque layer.
Claim 5
Dependent Claim
21 words
The method as claimed in claim 1 wherein the opaque area and the transparent area are defined on the opaque layer.
Claim 6
Dependent Claim
20 words
The method as claimed in claim 1 further comprising after said phase shifting layer removing step, removing the sidewall spacers.
Claim 7
Dependent Claim
17 words
The method as claimed in claim 1 wherein the sidewall spacers are formed of organic photosensitive material.
Claim 8
Independent Claim
108 words
A method for fabricating a lithography mask, comprising the steps of: depositing a phase shifting layer on a transparent substrate; depositing an opaque layer on the phase shifting layer; depositing a first organic photosensitive material on the opaque layer; selectively exposing and developing the first organic photosensitive material to define an opaque area and a transparent area; selectively removing the opaque layer of the transparent area; removing the first organic photosensitive material; forming second organic photosensitive material sidewall spacers of sidewalls of the opaque layer; and using the opaque layer and the second organic photosensitive material sidewall spacers as a mask, selectively removing the exposed phase shifting layer.
Claim 9
Independent Claim
108 words
A method for fabricating a lithography mask, comprising the steps of: depositing a phase shifting layer on a transparent substrate; depositing an opaque layer on the phase shifting layer; depositing a first organic photosensitive material on the opaque layer; selectively exposing and developing the first organic photosensitive material to define an opaque area and a transparent area; selectively removing the opaque layer of the transparent area; removing the first organic photosensitive material; forming second organic photosensitive material sidewall spacers of sidewalls of the opaque layer; and using the opaque layer and the second organic photosensitive material sidewall spacers as a mask, selectively removing the exposed phase shifting layer.
Claim 10
Dependent Claim
16 words
The method as claimed in claim 7 wherein the transparent substrate comprises a transparent quartz substrate.
Claim 11
Dependent Claim
28 words
The method as claimed in claim 7 wherein the first and the second organic photosensitive materials comprise materials photosensitive to ultra-violet rays, far ultra-violet rays and electron beams.
Claim 12
Dependent Claim
15 words
The method as claimed in claim 7 wherein the opaque layer is constructed of chrome.
Claim 13
Dependent Claim
15 words
The method as claimed in claim 7 wherein the opaque layer is constructed of aluminum.
Claim 14
Dependent Claim
17 words
The method as claimed in claim 7 wherein the phase shifting layer comprises a silicon oxide film.
Claim 15
Dependent Claim
16 words
The method as claimed in claim 7 wherein the phase shifting material comprises spin on glass.
Claim 16
Dependent Claim
15 words
The method as claimed in claim 7 wherein the phase shifting material comprises polymethyl methacrylate.
Claim 17
Dependent Claim
48 words
The method as claimed in claim 7 wherein a thickness T of the phase shifting layer is determined by the equation of T=λ/2 (n-1), where λ is a wavelength of an exposing light and n is a refractive index of the phase shifting layer against the exposing light.
Claim 18
Independent Claim
107 words
A method of fabricating a lithography mask, comprising the steps of: depositing a phase shifting layer on a transparent substrate; depositing an opaque layer on the phase shifting layer; depositing an organic photosensitive material on the opaque layer; exposing and developing the organic photosensitive material selectively to define an opaque area and a transparent area; selectively removing the opaque layer of the transparent area; forming sidewall spacers of the organic photosensitive material on opaque layer sidewalls by heat treatment of the organic photosensitive material; and using the opaque layer and the sidewall spacers of the organic photosensitive material as a mask, etching the exposed phase shifting layer.
Claim 19
Independent Claim
107 words
A method of fabricating a lithography mask, comprising the steps of: depositing a phase shifting layer on a transparent substrate; depositing an opaque layer on the phase shifting layer; depositing an organic photosensitive material on the opaque layer; exposing and developing the organic photosensitive material selectively to define an opaque area and a transparent area; selectively removing the opaque layer of the transparent area; forming sidewall spacers of the organic photosensitive material on opaque layer sidewalls by heat treatment of the organic photosensitive material; and using the opaque layer and the sidewall spacers of the organic photosensitive material as a mask, etching the exposed phase shifting layer.
Claim 20
Dependent Claim
20 words
The method as claimed in claim 16 wherein the heat treatment is carried out so as to cause thermal flow.
Claim 21
Dependent Claim
17 words
The method as claimed in claim 16 further comprising after said etching step, removing the sidewall spacers.
Claim 22
Dependent Claim
30 words
The method as claimed in claim 16 wherein the sidewall spacers are formed as a mask to obtain a pattern of the phase shifting layer wider than the opaque layer.
References Cited (Backward Citations)
US4707218A
Cited
US5268244A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-10-02 | 1999-04-03 | 1999-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-02 | 2003-04-03 | 2003-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-02 | 2007-04-03 | 2007-10-03 | $7700.00 | Window Closed / Lapsed |