Patent US5897977A successfully refreshed from Google Patents.
US5897977A
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Attenuating embedded phase shift photomask blanks
Assignee: Tekscend Photomasks Inc
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Filing: 1997-02-10
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Granted: 1999-04-27
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Expires: 2017-02-10
Abstract
Abstract Attenuating embedded phase shift photomask blanks capable of producing a 180 DEG phase shift with an optical transmissivity of at least 0.0001 at wavelengths <400 nm comprise alternating layers, either periodic or aperiodic, of an optically transmissive material and an optically absorbing material and are made by depositing alternating layers of optically transmissive material and optically absorbing material on a substrate, preferably by vapor deopsition.
Inventors
- 👤 Peter Francis Carcia
- 👤 Roger Harquail French
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:34
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/26; G03F1/32
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
48 words
An attenuating embedded phase shift photomask blank capable of producing a phase shift of 180° with an optical transmissivity of at least 0.001 a selected lithographic wavelength <400 nm, said photomask blank comprising distinct alternating layers of an optically transparent material and layers of an optically absorbing material.
Claim 2
Dependent Claim
48 words
An attenuating embedded phase shift photomask blank capable of producing a phase shift of 180° with an optical transmissivity of at least 0.001 a selected lithographic wavelength <400 nm, said photomask blank comprising distinct alternating layers of an optically transparent material and layers of an optically absorbing material.
Claim 3
Dependent Claim
29 words
The photomask blank of claim 1, wherein the optically transparent material is selected from the group consisting of metal oxides, metal nitrides, alkaline earth metal flourides, and mixtures thereof.
Claim 4
Dependent Claim
47 words
The photomask blank of claim 1, wherein the optically transparent material is selected from the group consisting of (a) oxides of Hf, Y, Zr, Al, Si, or Ge; (b) nitrides of Al, Si, B, or C; (c) fluorides of Mg, Ba, or Ca, and (d) mixtures thereof.
Claim 5
Dependent Claim
27 words
The photomask blank of claim 1, wherein the optically absorbing material is selected from the group consisting of elemental metals, metal oxides, metal nitrides and mixtures thereof.
Claim 6
Dependent Claim
62 words
The photomask blank of claim 1, wherein the optically absorbing material is selected from the group consisting of (a) oxides of Cr, Ti, Fe, In, Co, Bi, Mn, Cu, Sn, Ni, V, Ta, Mo, Ru, metals in the lanthanide series, or W; (b) nitrides of Ti, Nb, Mo, W, Ta, Hf, Y, Zr, or Cr; (c) elemental metals; and (d) mixtures thereof.
Claim 7
Dependent Claim
24 words
The photomask blank of claim 1, comprising at least two layers of optically transparent material and at least two layers of optically absorbing material.
Claim 8
Dependent Claim
12 words
The photomask blank of claim 1, wherein the alternating layers are periodic.
Claim 9
Dependent Claim
12 words
The photomask blank of claim 1, wherein the alternating layers are aperiodic.
Claim 10
Dependent Claim
58 words
A process of making attenuating embedded phase shift photomask blanks capable of producing a phase shift of 180° with an optical transmissivity of at least 0.001 at a selected lithographic wavelength <400 nm, said process comprising the steps of depositing distinct alternating layers of an optically transparent material and layers of an optically absorbing material onto a substrate.
Claim 11
Dependent Claim
58 words
A process of making attenuating embedded phase shift photomask blanks capable of producing a phase shift of 180° with an optical transmissivity of at least 0.001 at a selected lithographic wavelength <400 nm, said process comprising the steps of depositing distinct alternating layers of an optically transparent material and layers of an optically absorbing material onto a substrate.
Claim 12
Dependent Claim
11 words
The process of claim 9, wherein the alternating layers are periodic.
Claim 13
Dependent Claim
11 words
The process of claim 9, wherein the alternating layers are aperiodic.
Claim 14
Dependent Claim
28 words
The process of claim 9, wherein at least two layers of optically transparent material are deposited and wherein at least two layers of optically absorbing material are deposited.
Claim 15
Dependent Claim
28 words
The process of claim 9, wherein the optically transparent material is selected from the group consisting of metal oxides, metal nitrides, alkaline earth metal fluorides, and mixtures thereof.
Claim 16
Dependent Claim
46 words
The process of claim 9, wherein the optically transparent material is selected from the group consisting of (a) oxides of Hf, Y, Zr, Al, Si, or Ge; (b) nitrides of Al, Si, B, or C; (c) fluorides of Mg, Ba, or Ca, and (d) mixtures thereof.
Claim 17
Dependent Claim
25 words
The process of claim 9, wherein the optically absorbing materials is selected from the group consisting ofelemental metals, metal oxides, metal nitrides, and mixtures thereof.
Claim 18
Dependent Claim
60 words
The process of claim 9, wherein the optically absorbing material is selected from the group consisting of (a) oxides of Cr, Ti, Fe, In, Co, Bi, Mn, Cu, Sn, Ni, V, Ta, Mo, Ru, metals in the lanthanide series, or W; (b) nitrides of Ti, Nb, Mo, W, Ta, Hf, Zr, or Cr; (c) elemental metals; and (d) mixtures thereof.
Claim 19
Dependent Claim
14 words
The process of claim 9, wherein the alternating layers are deposited by vapor deposition.
Claim 20
Dependent Claim
13 words
The process of claim 9, wherein the layers are deposited by sputter deposition.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-04-26 | 2002-10-26 | 2003-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-04-26 | 2006-10-26 | 2007-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-04-26 | 2010-10-26 | 2011-04-27 | $7700.00 | Window Closed / Lapsed |