US4037111A
Expired / Lapsed
US
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Mask structures for X-ray lithography
Assignee: AT&T Inc
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Filing: 1976-06-08
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Granted: 1977-07-19
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Expires: 1996-06-08
Abstract
Abstract It has been observed that the deposition and patterning of metallic layers on a supported X-ray-transparent film to form a mask for X-ray lithography introduce stresses in the mask structure. In turn these stresses cause distortions of the film and of the high-resolution X-ray-absorptive pattern formed thereon. Various techniques, including new metallization systems, are proposed for minimizing the establishment of stresses in such structures.
Inventors
- 👤 Gerald Allan Coquin
- 👤 Juan Ramon Maldonado
- 👤 Dan Maydan
- 👤 Sasson Roger Somekh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:24
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/22; G21; G21K; G21K1/00; G21K1/10
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
37 words
A mask structure for X-ray lithography comprising a dimensionally stable support member, an X-ray-transparent film stretched over and bonded to said support member, and means including stress-compensating constituents for forming a very-low-stress X-ray-absorptive pattern on said substrate.
Claim 2
Dependent Claim
37 words
A mask structure for X-ray lithography comprising a dimensionally stable support member, an X-ray-transparent film stretched over and bonded to said support member, and means including stress-compensating constituents for forming a very-low-stress X-ray-absorptive pattern on said substrate.
Claim 3
Dependent Claim
71 words
A structure as in claim 1 wherein said forming means comprises a relatively thin patterned layer on said substrate, said layer comprising a mixture of metals characterized by respectively compensating stresses, a relatively thick correspondingly patterned X-ray-absorbent layer on said relatively thin layer, and another relatively thin correspondingly patterned layer on said relatively thick layer, said second-mentioned relatively thin layer also comprising a mixture of metals characterized by respectively compensating stresses.
Claim 4
Dependent Claim
24 words
A structure as in claim 2 wherein the metals included in each of said relatively thin layers comprise a mixture of tungsten and titanium.
Claim 5
Dependent Claim
24 words
A structure as in claim 2 wherein the metals included in each of said relatively thin layers comprise a mixture of tantalum and titanium.
Claim 6
Dependent Claim
92 words
A structure as in claim 1 wherein said forming means comprises two relatively thin patterned layers deposited on top of each other on said substrate, wherein said layers are metallic and are characterized by respectively compensating stresses, a relatively thick correspondingly patterned X-ray-absorbent layer deposited on top of the upper one of said two relatively thin patterned layers, and two additional relatively thin correspondingly patterned layers deposited on top of each other on said relatively thick layer, wherein said two additional layers are also metallic and also characterized by respectively compensating stresses.
Claim 7
Dependent Claim
27 words
A structure as in claim 5 wherein the two relatively thin layers below and above said relatively thick layer each are made of tungsten and titanium, respectively.
Claim 8
Dependent Claim
27 words
A structure as in claim 6 wherein the two relatively thin layers below and above said relatively thick layer each are made of tantalum and titanium, respectively.
Claim 9
Dependent Claim
36 words
A structure as in claim 1 further including an X-ray-transparent layer deposited on said pattern on one side of said film to protect the pattern from physical damage and to stop photoelectrons emitted from the pattern.
Claim 10
Dependent Claim
45 words
A structure as in claim 8 further including an additional X-ray-transparent layer deposited on top of said first-mentioned layer for capturing dirt particles, said additional layer being adapted to be periodically and easily removed from said structure to maintain the surface cleanliness of the structure.
Claim 11
Dependent Claim
26 words
A structure as in claim 9 further including an X-ray-transparent coating deposited on the other side of said film for increasing the stiffness of said film.
Claim 12
Dependent Claim
15 words
A structure as in claim 10 wherein said coating comprises a 2-μm-thick layer of beryllium.
Claim 13
Dependent Claim
16 words
A structure as in claim 10 wherein said coating comprises a 10-μm-thick layer of silicon nitride.
Claim 14
Dependent Claim
18 words
A structure as in claim 10 wherein said support member is formed in the shape of a ring.
Claim 15
Dependent Claim
17 words
A structure as in claim 13 wherein said ring-shaped support member is made of a borosilicate glass.
Claim 16
Dependent Claim
13 words
A structure as in claim 14 wherein said film is a polyimide film.
Claim 17
Dependent Claim
48 words
A mask structure for X-ray lithography comprising a dimensionally stable support member, an X-ray-transparent film stretched over and bonded to said support member, and an essentially stress-free X-ray-absorptive pattern disposed on said film in a uniformly distributed way, the peripheral portion of said pattern overlying said support member.
Claim 18
Dependent Claim
48 words
A mask structure for X-ray lithography comprising a dimensionally stable support member, an X-ray-transparent film stretched over and bonded to said support member, and an essentially stress-free X-ray-absorptive pattern disposed on said film in a uniformly distributed way, the peripheral portion of said pattern overlying said support member.
Claim 19
Dependent Claim
36 words
A structure as in claim 16 wherein said pattern comprises elements made of a relatively thick X-ray-absorptive material, first stress-compensated means adhering said elements to said film, and second stress-compensated means on top of said elements.
Claim 20
Dependent Claim
24 words
A structure as in claim 17 wherein each of said first and second stress-compensated means is made of a mixture of tungsten and titanium.
Claim 21
Dependent Claim
24 words
A structure as in claim 17 wherein each of said first and second stress-compensated means is made of a mixture of tantalum and titanium.
Claim 22
Dependent Claim
28 words
A structure as in claim 17 wherein each of said first and second stress-compensated means comprises two thin films, one made of tungsten and the other of titanium.
Claim 23
Dependent Claim
28 words
A structure as in claim 17 wherein each of said first and second stress-compensated means comprises two thin films, one made of tantalum and the other of titanium.
Claim 24
Dependent Claim
69 words
A mask structure for X-ray lithography comprising a dimensionally stable support member, an X-ray-transparent film stretched over and bonded to said support member, means including stress-compensating constituents for forming a very-low-stress X-ray-absorptive pattern on said substrate, and conductive means in contact with said film for equalizing charges acquired by said mask structure due to the ejection of photo-electrons from said forming means during irradiation of said structure by X-rays.
Claim 25
Dependent Claim
69 words
A mask structure for X-ray lithography comprising a dimensionally stable support member, an X-ray-transparent film stretched over and bonded to said support member, means including stress-compensating constituents for forming a very-low-stress X-ray-absorptive pattern on said substrate, and conductive means in contact with said film for equalizing charges acquired by said mask structure due to the ejection of photo-electrons from said forming means during irradiation of said structure by X-rays.
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) | 1980-07-18 | 1981-01-17 | 1981-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-18 | 1985-01-17 | 1985-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-18 | 1989-01-17 | 1989-07-19 | $7700.00 | Window Closed / Lapsed |