US5459002A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photomask blanks
Assignee: DU PONT CHEMICAL AND ENERGY OPERATIONS Inc
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Filing: 1994-03-28
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Granted: 1995-10-17
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Expires: 2014-03-28
Abstract
Abstract Transmissive embedded phase shifter-photomask blanks are disclosed which comprise an optically inhomogeneous attenuating film which has a transmission of at least 0.001 and consists essentially of a combination of a metallic component and a dielectric component. One surface of the film has a higher content of metallic component than the other surface and the profile of change in extinction coefficient is gradual through the film thickness. The profile of change in extinction coefficient and the film thickness are selected to provide a phase shift of about 180 DEG (or an odd multiple thereof) at a selected wavelength.
Inventors
- 👤 Hakki U. Alpay
- 👤 Roger H. French
- 👤 Franklin D. Kalk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:17
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/26; G03F1/32; G03F1/54
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
99 words
A transmissive embedded phase shifter-photomask blank for a selected wavelength comprising an optically inhomogeneous attenuating film having a transmission of at least 0.001 and consisting essentially of a combination of a metallic component and a dielectric component; wherein one surface of the film has a higher content of metallic component than the other surface, and the profile of change in the extinction coefficient is gradual through the film thickness; and wherein said profile of change and the film thickness are selected to provide a phase shift of about 180° , or an odd multiple thereof, at the selected wavelength.
Claim 2
Dependent Claim
99 words
A transmissive embedded phase shifter-photomask blank for a selected wavelength comprising an optically inhomogeneous attenuating film having a transmission of at least 0.001 and consisting essentially of a combination of a metallic component and a dielectric component; wherein one surface of the film has a higher content of metallic component than the other surface, and the profile of change in the extinction coefficient is gradual through the film thickness; and wherein said profile of change and the film thickness are selected to provide a phase shift of about 180° , or an odd multiple thereof, at the selected wavelength.
Claim 3
Dependent Claim
17 words
The transmissive embedded phase shifter-photomask blank of claim 1 wherein the phase shift is about 180° .
Claim 4
Dependent Claim
21 words
The transmissive embedded phase shifter-photomask blank of claim 2 wherein the reflectivity is within the range of from 0 to 0.5.
Claim 5
Dependent Claim
38 words
The transmissive embedded phase shifter-photomask blank of claim 3 wherein the metallic component is from 85% to 5% of the film by volume and wherein the dielectric component is from 15% to 95% of the film by volume.
Claim 6
Dependent Claim
27 words
The transmissive embedded phase shifter-photomask blank of claim 1, claim 2, claim 3, or claim 4 wherein the selected wavelength is from 110 nm to 1000 nm.
Claim 7
Dependent Claim
48 words
The transmissive embedded phase shifter-photomask blank of claim 5 wherein the metallic component and dielectric component are M--O--C--N materials, M--Cl--O--C--N materials, M--Cl--F--O--C--N materials or M--F--O--C--N materials where M is selected from the group consisting of Cr, Fe, Mo, Zn, Co, Nb, Ta, W, Ti, Al, Mg, and Si.
Claim 8
Dependent Claim
13 words
The transmissive embedded phase shifter-photomask blank of claim 6 wherein M is Cr.
Claim 9
Dependent Claim
19 words
The transmissive embedded phase shifter-photomask blank of claim 7 wherein the metallic component and dielectric component are Cr-0-C--N materials.
References Cited (Backward Citations)
US4415262A
Cited
EP0203563A2
Cited
US4890309A
Cited
JPH02242252A
Cited
JPH04125643A
Cited
US5230971A
Cited
US5187726A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-10-16 | 1999-04-17 | 1999-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-16 | 2003-04-17 | 2003-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-16 | 2007-04-17 | 2007-10-17 | $7700.00 | Window Closed / Lapsed |