Patent US5556724A successfully refreshed from Google Patents.
US5556724A
Expired / Lapsed
US
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Phase shift photomask and method of producing same
Assignee: Dai Nippon Printing Co Ltd
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Filing: 1993-11-09
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Granted: 1996-09-17
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Expires: 2013-11-09
Abstract
Abstract A phase shift photomask is produced in the following manner. Before or after a light-shielding pattern is formed on a substrate, a transparent film serving as a phase shifter is coated onto the substrate, and the transparent film in a photomask-pattern-forming area exluding the peripheral area of the substrate is irradiated with energy rays. The irradiated portion of the transparent film is thus solidified. The unsolidified portion of the transparent film is removed by etching. A phase shifter pattern is thus formed on the substrate excluding the peripheral area of the substrate. Since the phase shifter pattern is not exposed at the peripheral area of the substrate, a dust which is usually made when the phase shifter pattern formed in this area cracks or peels off the substrate is not made. The number of defective photomasks to be produced can thus be reduced.
Inventors
- 👤 Norihiro Tarumoto
- 👤 Hiroyuki Inomata
- 👤 Takashi Tominaga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:21
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/26; G03F1/30; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24851; Y10T428/24868; Y10T428/24917; Y10T428/24926
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
73 words
A method for producing a phase shift photomask comprising the steps of: coating a transparent film serving as a phase shifter onto a substrate; solidifying the transparent film in a photomask-pattern-forming area excluding a peripheral area of the substrate, while leaving the transparent film in the area excluding the photomask-pattern-forming area unsolidified; and removing the unsolidified transparent film by etching in order to leave the solidified transparent film only in the photomask-pattern-forming area.
Claim 2
Independent Claim
73 words
A method for producing a phase shift photomask comprising the steps of: coating a transparent film serving as a phase shifter onto a substrate; solidifying the transparent film in a photomask-pattern-forming area excluding a peripheral area of the substrate, while leaving the transparent film in the area excluding the photomask-pattern-forming area unsolidified; and removing the unsolidified transparent film by etching in order to leave the solidified transparent film only in the photomask-pattern-forming area.
Claim 3
Dependent Claim
30 words
A method for producing a phase shift photomask as set forth in claim 1, wherein the transparent film serving as a phase shifter is formed by using a spin-on glass.
Claim 4
Dependent Claim
35 words
A method for producing a phase shift photomask as set forth in claim 1, wherein the transparent film serving as a phase shifter is solidified by irradiation of energy rays conducted through a light-shielding film.
Claim 5
Dependent Claim
21 words
A method for producing a phase shift photomask as set forth in claim 3, wherein the energy rays are ultraviolet rays.
Claim 6
Dependent Claim
20 words
A method for producing a phase shift photomask as set forth in claim 3, wherein the energy rays are X-rays.
Claim 7
Dependent Claim
26 words
A method for producing a phase shift photomask as set forth in claim 1, wherein the unsolidified transparent film is etched by using an organic solvent.
Claim 8
Dependent Claim
41 words
A method for producing a phase shift photomask as set forth in claim 1, wherein after a light-shielding pattern is formed on the substrate, the transparent film serving as a phase shifter is coated onto the substrate through the light-shielding pattern.
Claim 9
Dependent Claim
31 words
A method for producing a phase shift photomask as set forth in claim 7, wherein the solidified transparent film remaining in the photomask-pattern-forming area is made into a phase shifter pattern.
Claim 10
Dependent Claim
29 words
A method for producing a phase shift photomask as set forth in claim 1, wherein the transparent film serving as a phase shifter is directly coated onto the substrate.
Claim 11
Dependent Claim
58 words
A method for producing a phase shift photomask as set forth in claim 9, wherein a light-shielding film is provided on the substrate so as to cover the solidified transparent film remaining in the photomask-pattern-forming area, and made into a light-shielding pattern; and the solidified transparent film is made into a phase shifter pattern through the light-shielding pattern.
Claim 12
Independent Claim
93 words
A method for producing a phase shift photomask comprising the steps of: forming a resist layer on a substrate; leaving the resist layer only in a peripheral area of the substrate; providing a transparent film serving as a phase shifter on both the remaining resist layer and the surface of the substrate; and removing the remaining resist layer together with the transparent film formed thereon by applying a solvent to the remaining resist layer in order to leave the transparent film only in a photomask-pattern-forming area excluding the peripheral area of the substrate.
Claim 13
Independent Claim
93 words
A method for producing a phase shift photomask comprising the steps of: forming a resist layer on a substrate; leaving the resist layer only in a peripheral area of the substrate; providing a transparent film serving as a phase shifter on both the remaining resist layer and the surface of the substrate; and removing the remaining resist layer together with the transparent film formed thereon by applying a solvent to the remaining resist layer in order to leave the transparent film only in a photomask-pattern-forming area excluding the peripheral area of the substrate.
Claim 14
Dependent Claim
43 words
A method for producing a phase shift photomask as set forth in claim 11, wherein the resist layer in the peripheral area of the substrate is irradiated with energy rays and then developed in order to leave the resist layer in this area.
Claim 15
Dependent Claim
63 words
A phase shift photomask comprising: a substrate having a peripheral area along an outer peripheral edge thereof; a light-shielding pattern formed on the substrate and including a photomask pattern-forming area; and a phase shifter pattern formed on both the substrate and the light-shielding pattern, said phase shifter pattern being provided in an area including said photomask pattern-forming area and excluding said peripheral area.
Claim 16
Dependent Claim
63 words
A phase shift photomask comprising: a substrate having a peripheral area along an outer peripheral edge thereof; a light-shielding pattern formed on the substrate and including a photomask pattern-forming area; and a phase shifter pattern formed on both the substrate and the light-shielding pattern, said phase shifter pattern being provided in an area including said photomask pattern-forming area and excluding said peripheral area.
Claim 17
Dependent Claim
44 words
A phase shift photomask blank comprising: a substrate having a peripheral area along an outer peripheral edge thereof; and a transparent film serving as a phase shifter and formed on the substrate, said transparent film being provided in an area excluding said peripheral area.
Claim 18
Dependent Claim
44 words
A phase shift photomask blank comprising: a substrate having a peripheral area along an outer peripheral edge thereof; and a transparent film serving as a phase shifter and formed on the substrate, said transparent film being provided in an area excluding said peripheral area.
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) | 1999-09-17 | 2000-03-18 | 2000-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-17 | 2004-03-18 | 2004-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-17 | 2008-03-18 | 2008-09-17 | $7700.00 | Window Closed / Lapsed |