US3742230A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Soft x-ray mask support substrate
Assignee: Massachusetts Institute of Technology
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Filing: 1972-06-29
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Granted: 1973-06-26
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Expires: 1992-06-29
Abstract
Abstract A soft X-ray mask support substrate including a thick peripheral support structure; a thin, taut membrane, transparent to soft Xrays and carried by the support structure covering the area within the periphery; and a soft X-ray absorber layer arranged in a predetermined pattern on the membrane within the periphery of the support structure.
Inventors
- 👤 D Spears
- 👤 H Smith
- 👤 E Stern
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:07
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/22; G21; G21K; G21K1/00; G21K1/10; Y; Y10; Y10S; Y10S430/00; Y10S430/167; Y10S430/168
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
16 words
The substrate of claim 1 in which said membrane is formed integrally with said support structure.
Claim 2
Dependent Claim
28 words
The substrate of claim 1 in which said absorber layer includes an absorber element and an intermediate element for improving adherence between said membrane and said absorber element.
Claim 3
Dependent Claim
87 words
A soft X-ray support substrate comprising: a thick silicon peripheral support structure; and a thin, taut, silicon membrane transparent to soft X-rays and carried by said support structure covering the area within the periphery of said support structure for carrying a soft X-ray absorber layer arranged in a predetermined pattern on said membrane within said periphery of said support structure; said membrane being doped with boron having a smaller covalent bond radius than silicon to shrink said membrane to produce tension in it and make it taut.
Claim 4
Dependent Claim
87 words
A soft X-ray support substrate comprising: a thick silicon peripheral support structure; and a thin, taut, silicon membrane transparent to soft X-rays and carried by said support structure covering the area within the periphery of said support structure for carrying a soft X-ray absorber layer arranged in a predetermined pattern on said membrane within said periphery of said support structure; said membrane being doped with phosphorous having a smaller covalent bond radius than silicon to shrink said membrane to produce tension in it and make it taut.
Claim 5
Dependent Claim
90 words
A soft X-ray support substrate comprising: a thick silicon peripheral support structure, and a thin, taut silicon membrane transparent to soft X-rays and carried by said support structure covering the area within the periphery of said support structure for carrying a soft X-ray absorber layer arranged in a predetermined pattern on said membrane within said periphery of said support structure; said support structure being doped with a material having a larger covalent bond radius than silicon to expand said support structure and produce tension in said membrane making it taut.
Claim 6
Dependent Claim
89 words
A soft X-ray support substrate comprising: a thick silicon peripheral support structure, and a thin, taut silicon membrane transparent to soft X-rays and carried by said support structure covering the area within the periphery of saiD support structure for carrying a soft X-ray abosrber layer arranged in a predetermined pattern on said membrane within said periphery of said support structure; said support structure being doped with anitmony having a larger covalent bond radius than silicon to expand said support structure and produce tension in said membrane making it taut.
Claim 7
Dependent Claim
89 words
A soft X-ray support substrate comprising: a thick silicon peripheral support structure, and a thin, taut silicon membrane transparent to soft X-rays and carried by said support structure covering the area within the periphery of said support structure for carrying a soft X-ray absorber layer arranged in a predetermined pattern on said membrane within said periphery of said support structure; said support structure being doped with gallium having a larger covalent bond radius than silicon to expand said support structure and produce tension in said membrane making it taut.
Claim 8
Dependent Claim
89 words
A soft X-ray support substrate comprising: a thick silicon peripheral support structure, and a thin, taut silicon membrane transparent to soft X-rays and carried by said support structure covering the area within the periphery of said support structure for carrying a soft X-ray absorber layer arranged in a predetermined pattern on said membrane within said periphery of said support structure; said support structure being doped with arsenic having a larger covalent bond radius than silicon to expand said support structure and produce tension in said membrane making it taut.
Claim 9
Dependent Claim
89 words
A soft X-ray support substrate comprising: a thick silicon peripheral support structure, and a thin, taut silicon membrane transparent to soft X-rays and carried by said support structure covering the area within the periphery of said support structure for carrying a soft X-ray absorber layer arranged in a predetermined pattern on said membrane within said periphery of said support structure; said support structure being doped with aluminum having a larger covalent bond radius than silicon to expand said support structure and produce tension in said membrane making it taut.
Claim 10
Independent Claim
133 words
A method of making a soft X-ray mask support substrate comprising: doping a first surface of a silicon substrate with boron to a predetermined thickness to shrink that doped portion of said silicon substrate; providing an etch resistant layer on the second surface of said substrate except in the area corresponding to the area on the first surface for carrying a predetermined pattern in soft X-ray absorber material; and subjecting the exposed said area of said second surface to an etchant which attacks the silicon of the support substrate and which is ineffective in etching the boron doped silicon and the etch resistant layer to create a window in the silicon substrate covered by a membrane formed from the boron doped silicon and kept taut by the shrinking of the boron doped silicon.
Claim 11
Independent Claim
133 words
A method of making a soft X-ray mask support substrate comprising: doping a first surface of a silicon substrate with phosphorous to a predetermined thickness to shrink that doped portion of said silicon substrate; providing an etch resistant layer on the second surface of said substrate except in the area corresponding to the area on the first surface for carrying a predetermined pattern in soft X-ray absorber material; and subjecting the exposed said area of said second surface to an etchant which attacks the silicon of the support substrate and which is ineffective in etching the phosphorous doped silicon and the etch resistant layer to create a window in the silicon substrate covered by a membrane formed from the phosphorous doped silicon and kept taut by the shrinking of the phosphorous doped silicon.
Claim 12
Independent Claim
132 words
A method of making a soft X-ray support substrate comprising: doping a wafer of silicon with antimony to expand said wafer; depositing a layer of silicon on a first surface of said wafer; providing an etch resistant layer on the second surfacE of said wafer except in the area corresponding to the area on the first surface for carrying a predetermined pattern in soft X-ray absorber material; and subjecting said exposed area of said second surface to an etchant which attacks said silicon wafer doped with antimony and which is ineffective in etching the silicon layer and the etch resistant layer to create a window in the antimony doped silicon wafer covered by a membrane formed from the silicon layer and kept taut by the expansion of the antimony doped silicon wafer.
Claim 13
Independent Claim
132 words
A method of making a soft X-ray support substrate comprising: doping a wafer of silicon with gallium to expand said wafer; depositing a layer of silicon on a first surface of said wafer; providing an etch resistant layer on the second surface of said wafer except in the area corresponding to the area on the first surface for carrying a predetermined pattern in soft X-ray absorber material; and subjecting said exposed area of said second surface to an etchant which attacks said silicon wafer doped with gallium and which is ineffective in etching the silicon layer and the etch resistant layer to create a window in the gallium doped silicon wafer covered by a membrane formed from the silicon layer and kept taut by the expansion of the gallium doped silicon wafer.
Claim 14
Independent Claim
132 words
A method of making a soft X-ray support substrate comprising: doping a wafer of silicon with arsenic to expand said wafer; depositing a layer of silicon on a first surface of said wafer; providing an etch resistant layer on the second surface of said wafer except in the area corresponding to the area on the first surface for carrying a predetermined pattern in soft X-ray absorber material; and subjecting said exposed area of said second surface to an etchant which attacks said silicon wafer doped with arsenic and which is ineffective in etching the silicon layer and the etch resistant layer to create a window in the arsenic doped silicon wafer covered by a membrane formed from the silicon layer and kept taut by the expansion of the arsenic doped silicon wafer.
Claim 15
Independent Claim
132 words
A method of making a soft X-ray support substrate comprising: doping a wafer of silicon with aluminum to expand said wafer; depositing a layer of silicon on a first surface of said wafer; providing an etch resistant layer on the second surface of said wafer except in the area corresponding to the area on the first surface for carrying a predetermined pattern in soft X-ray absorber material; and subjecting said exposed area of said second surface to an etchant which attacks said silicon wafer doped with aluminum and which is ineffective in etching the silicon layer and the etch resistant layer to create a window in the aluminum doped silicon wafer covered by a membrane formed from the silicon layer and kept taut by the expansion of the aluminum doped silicon wafer.
References Cited (Backward Citations)
US3637380A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-25 | 1976-12-25 | 1977-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-25 | 1980-12-25 | 1981-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-25 | 1984-12-25 | 1985-06-26 | $7700.00 | Window Closed / Lapsed |