US4388728A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Soft X-ray lithography system
Assignee: Varian Medical Systems Inc
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Filing: 1978-11-20
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Granted: 1983-06-14
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Expires: 1998-11-20
Abstract
Abstract A soft X-ray lithography system including an X-ray tube having an evacuated and sealed-off envelope provided with an X-ray transparent window made of beryllium material and enclosing a rotatable anode target made of graphite material, the target having an annular sloped surface carrying a focal track layer made of titanium carbide material and having a focal spot area aligned with an electron emitting cathode to generate characteristic titanium K alpha X-rays which pass in a beam through the window, a mask aligned with the window and having transparent portions which transmit the beamed X-rays, and a workpiece, such as a semiconductor wafer, for example, having a surface coated with a photoresist film disposed in alignment with the mask to have selected portions of the film irradiated by the X-rays transmitted through the transparent portions of the mask.
Inventors
- 👤 Saurabh D. Emmanuel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:05
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70008; G03F7/70033; G03F7/708; G03F7/70808; Y; Y10; Y10S; Y10S430/00; Y10S430/167; Y10S430/168
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
107 words
An X-ray lithography method comprising the steps of: disposing an X-ray source having a target made of a chemical compound material for emitting X-rays characteristic of the elements in said compound along a predetermined path; disposing in said path a filter made of material transmissive to X-rays characteristic of only one of said elements; disposing in alignment with said filter a mask having a portion transmissive to X-rays characteristic of said only one of said elements; and disposing in alignment with said portion of the mask a workpiece having a surface portion coated with a material sensitive to X-rays characteristic of said only one of said elements.
Claim 2
Dependent Claim
107 words
An X-ray lithography method comprising the steps of: disposing an X-ray source having a target made of a chemical compound material for emitting X-rays characteristic of the elements in said compound along a predetermined path; disposing in said path a filter made of material transmissive to X-rays characteristic of only one of said elements; disposing in alignment with said filter a mask having a portion transmissive to X-rays characteristic of said only one of said elements; and disposing in alignment with said portion of the mask a workpiece having a surface portion coated with a material sensitive to X-rays characteristic of said only one of said elements.
Claim 3
Dependent Claim
94 words
An X-ray lithography method comprising the steps of: disposing an X-ray source having a target made of chemical compound material for emitting a beam of desired characteristic X-rays having energy levels in the order of forty-five hundred electron volts and other characteristic X-rays having energy levels substantially less than forty-five hundred electron volts; disposing in said beam a mask having a portion transmissive to said desired characteristic X-rays; and disposing a workpiece having a surface portion coated with a material sensitive to said desired characteristic X-rays in alignment with said portion of the mask.
Claim 4
Dependent Claim
94 words
An X-ray lithography method comprising the steps of: disposing an X-ray source having a target made of chemical compound material for emitting a beam of desired characteristic X-rays having energy levels in the order of forty-five hundred electron volts and other characteristic X-rays having energy levels substantially less than forty-five hundred electron volts; disposing in said beam a mask having a portion transmissive to said desired characteristic X-rays; and disposing a workpiece having a surface portion coated with a material sensitive to said desired characteristic X-rays in alignment with said portion of the mask.
Claim 5
Dependent Claim
60 words
An X-ray lithographic method comprising the steps of: disposing an X-ray source for emitting X-rays characteristic of titanium along a predetermined path; disposing in said path a mask having a portion transmissive of X-rays; and disposing a workpiece having a surface portion coated with a layer of material sensitive to said X-rays in alignment with said portion of the mask.
Claim 6
Dependent Claim
60 words
An X-ray lithographic method comprising the steps of: disposing an X-ray source for emitting X-rays characteristic of titanium along a predetermined path; disposing in said path a mask having a portion transmissive of X-rays; and disposing a workpiece having a surface portion coated with a layer of material sensitive to said X-rays in alignment with said portion of the mask.
Claim 7
Dependent Claim
96 words
An X-ray lithography system comprising: X-ray means including an X-ray emissive target made of a chemical compound material having a plurality of elements chemically bound to one another for directing emitted X-rays characteristic of said elements along a predetermined path, one of said elements emitting characteristic X-rays having respective wavelengths between two and three angstroms; a mask disposed in said path and having an X-ray transmissive portion; and workpiece means having a surface portion coated with X-ray sensitive material and disposed in alignment with said portion of the mask for receiving X-rays passed through said portion.
Claim 8
Dependent Claim
96 words
An X-ray lithography system comprising: X-ray means including an X-ray emissive target made of a chemical compound material having a plurality of elements chemically bound to one another for directing emitted X-rays characteristic of said elements along a predetermined path, one of said elements emitting characteristic X-rays having respective wavelengths between two and three angstroms; a mask disposed in said path and having an X-ray transmissive portion; and workpiece means having a surface portion coated with X-ray sensitive material and disposed in alignment with said portion of the mask for receiving X-rays passed through said portion.
Claim 9
Dependent Claim
38 words
An X-ray lithography system as set forth in claim 4 wherein said X-ray source means includes an electron source disposed for directing electrons onto said target and generating said X-rays characteristic of said elements in the target material.
Claim 10
Dependent Claim
25 words
An X-ray lithography system as set forth in claim 5 wherein said chemical compound material has a melting temperature greater than three thousand degrees Centigrade.
Claim 11
Dependent Claim
67 words
An X-ray lithographic system as set forth in claim 5 wherein said X-ray source comprises an X-ray tube having an evacuated envelope wherein said target and said electron source are disposed in spaced relationship and said envelope includes a window portion made of material substantially transparent to X-rays characteristic of said one of said elements and substantially absorbent to X-rays characteristic of another one of said elements.
Claim 12
Dependent Claim
29 words
An X-ray lithographic system as set forth in claim 7 wherein the X-rays characteristic of said other one of the elements have respective wavelengths substantially longer than three angstroms.
Claim 13
Dependent Claim
151 words
An X-ray lithography system comprising: X-ray source means for emitting a beam of X-rays having energy values in the order of forty-five hundred electron volts and including an X-ray emissive target made of chemical compound material having at least two elements chemically bound to one another, one of said elements emitting characteristic X-rays having respective energy values in the order of forty-five hundred electron volts and the other of said elements emitting characteristic X-rays having energy values substantially less than forty-five hundred electron volts, and filter means disposed with respect to said target for permitting passage of said X-rays having energy values in the order of forty-five hundred electron volts; a mask disposed in said beam and having an X-ray transmissive portion; and workpiece means having a surface portion coated with X-ray sensitive material and disposed in alignment with said portion of the mask for receiving X-rays passed through said portion.
Claim 14
Dependent Claim
151 words
An X-ray lithography system comprising: X-ray source means for emitting a beam of X-rays having energy values in the order of forty-five hundred electron volts and including an X-ray emissive target made of chemical compound material having at least two elements chemically bound to one another, one of said elements emitting characteristic X-rays having respective energy values in the order of forty-five hundred electron volts and the other of said elements emitting characteristic X-rays having energy values substantially less than forty-five hundred electron volts, and filter means disposed with respect to said target for permitting passage of said X-rays having energy values in the order of forty-five hundred electron volts; a mask disposed in said beam and having an X-ray transmissive portion; and workpiece means having a surface portion coated with X-ray sensitive material and disposed in alignment with said portion of the mask for receiving X-rays passed through said portion.
Claim 15
Dependent Claim
142 words
A soft X-ray lithography system comprising: a soft X-ray tube having an evacuated envelope provided with a window made of soft X-ray transmissive material; an anode target having a soft X-ray emissive surface made of titanium carbide material and disposed within the envelope in alignment with the window; electron emitting cathode means spaced from the soft X-ray emissive surface in the envelope for directing electrons onto the surface and generating soft X-rays which pass in a beam through the window; a workpiece disposed externally of the tube and having an adjacent surface portion disposed in spaced alignment with the window; a film of soft X-ray sensitive material disposed on the surface portion of the workpiece; and a shadow mask disposed between the window and the film; the mask having a pattern of soft X-ray transparent portions and interposed soft X-ray opaque portions.
Claim 16
Dependent Claim
142 words
A soft X-ray lithography system comprising: a soft X-ray tube having an evacuated envelope provided with a window made of soft X-ray transmissive material; an anode target having a soft X-ray emissive surface made of titanium carbide material and disposed within the envelope in alignment with the window; electron emitting cathode means spaced from the soft X-ray emissive surface in the envelope for directing electrons onto the surface and generating soft X-rays which pass in a beam through the window; a workpiece disposed externally of the tube and having an adjacent surface portion disposed in spaced alignment with the window; a film of soft X-ray sensitive material disposed on the surface portion of the workpiece; and a shadow mask disposed between the window and the film; the mask having a pattern of soft X-ray transparent portions and interposed soft X-ray opaque portions.
Claim 17
Dependent Claim
29 words
A soft X-ray lithography system as set forth in claim 10 wherein the anode target comprises a rotatable disc having an outer peripheral surface made of titanium carbide material.
Claim 18
Dependent Claim
27 words
A soft X-ray lithography system as set forth in claim 10 wherein the mask comprise a sheet of soft X-ray transparent material having soft X-ray opaque portions.
Claim 19
Dependent Claim
19 words
A soft X-ray lithography system as set forth in claim 10 wherein the window is made of beryllium material.
Claim 20
Dependent Claim
26 words
A soft X-ray lithography system as set forth in claim 13 wherein the beryllium material has a thickness of five to ten thousands of an inch.
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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) | 1986-06-13 | 1986-12-13 | 1987-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-13 | 1990-12-13 | 1991-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-13 | 1994-12-13 | 1995-06-14 | $7700.00 | Window Closed / Lapsed |