US4632871A
Expired / Lapsed
US
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Anodic bonding method and apparatus for X-ray masks
Assignee: HP Inc
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Filing: 1984-02-16
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Granted: 1986-12-30
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Expires: 2004-02-16
Abstract
Abstract A structure for use in an X-ray membrane (pellicle) mask is provided in which anodic bonding of layers is employed. Anodic bonding as used here provides a permanent bond between the layers, has zero thickness and provides substantial improvements in the obtained flatness of the mask by eliminating conventional glue for attachment. By applying a voltage between a layer, such as silicon, and a glass plate, and simultaneously heating both elements a permanent bond is established which is extremely flat thus providing minimum misalignment of the mask during subsequent X-ray lithography fabrication.
Inventors
- 👤 Marcos Karnezos
- 👤 Howard H. Nakanos
- 👤 Armand P. Neukermans
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:22
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/22; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
116 words
A mask structure for X-ray lithography comprising: a thin flat X-ray transmissive membrane selected from the group consisting of boron nitride, boron carbide, silicon nitride, silicon carbide, including a working area for forming an absorber pattern and a peripheral area for support thereof; a rigid support frame having a flat surface for supporting said membrane outwardly of the working area; and interface means interposed between the membrane and the flat surface of the support frame for facilitating anodic bonding of the membrane to the support frame without the use of adhesive material so as to provide an extremely flat, stable membrane surface, said interface means being anodically bonded to the flat surface of the support frame.
Claim 2
Dependent Claim
116 words
A mask structure for X-ray lithography comprising: a thin flat X-ray transmissive membrane selected from the group consisting of boron nitride, boron carbide, silicon nitride, silicon carbide, including a working area for forming an absorber pattern and a peripheral area for support thereof; a rigid support frame having a flat surface for supporting said membrane outwardly of the working area; and interface means interposed between the membrane and the flat surface of the support frame for facilitating anodic bonding of the membrane to the support frame without the use of adhesive material so as to provide an extremely flat, stable membrane surface, said interface means being anodically bonded to the flat surface of the support frame.
Claim 3
Dependent Claim
17 words
The mask structure as defined in claim 1 wherein said interface means comprises a metal interface layer.
Claim 4
Dependent Claim
14 words
The mask structure as defined in claim 2 wherein said membrane comprises boron nitride.
Claim 5
Dependent Claim
22 words
The mask structure as defined in claim 3 wherein said membrane has a thickness in the range of 2 to 6 microns.
Claim 6
Dependent Claim
14 words
The mask structure as defined in claim 2 wherein said metal layer comprises aluminum.
Claim 7
Dependent Claim
51 words
The mask structure as defined in claim 2 wherein said metal layer comprises a first metal selected from the group consisting of chromium and titanium, said first metal being deposited on the membrane, said metal layer further comprising aluminum deposited on said first metal and anodically bonded to said support frame.
Claim 8
Dependent Claim
23 words
The mask structure as defined in claim 6 wherein the metal layer has a thickness in the range of 0.1 to 0.5 micron.
Claim 9
Dependent Claim
17 words
The mask structure as defined in claim 7 wherein the support frame comprises a borosilicate glass ring.
Claim 10
Dependent Claim
49 words
The mask structure as defined in claim 1 wherein said interface means comprises a silicon layer with said membrane deposited on a first surface thereof, and a metal layer interposed between a second surface of said silicon layer and said support frame and anodically bonded to the support frame.
Claim 11
Dependent Claim
40 words
The mask structure as defined in claim 9 wherein said metal layer comprises chromium deposited on the second surface of the silicon layer, said metal layer further comprising aluminum deposited on the chromium and anodically bonded to said support frame.
Claim 12
Dependent Claim
30 words
The mask structure as defined in claim 9 wherein said metal layer comprises aluminum deposited on the second surface of the silicon layer and anodically bonded to said support frame.
Claim 13
Dependent Claim
25 words
The mask structure as defined in claim 9 wherein said metal layer is selected from the group consisting of nickel, titanium, silicon and combinations thereof.
Claim 14
Dependent Claim
23 words
The mask structure as defined in claim 10 wherein said membrane is selected from the group consisting of boron nitride and silicon carbide.
Claim 15
Dependent Claim
56 words
The mask structure as defined in claim 1 wherein said interface means comprises a silicon layer with said membrane deposited on a first surface thereof, and a layer of the membrane material interposed between a second surface of the silicon and the support frame, said layer of membrane material being anodically bonded to the support frame.
Claim 16
Dependent Claim
27 words
The mask structure as defined in claim 14 wherein said membrane is selected from the group consisting of boron nitride silicon carbide, boron carbide and silicon nitride.
Claim 17
Dependent Claim
22 words
The mask structure as defined in claim 1 wherein said interface means comprises a silicon layer anodically bonded to said support frame.
Claim 18
Dependent Claim
23 words
The mask structure as defined in claim 16 wherein said membrane is selected from the group consisting of boron nitride and silicon carbide.
Claim 19
Dependent Claim
23 words
The mask structure as defined in claim 17 wherein a layer of silicon dioxide is interposed between the membrane and the silicon layer.
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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) | 1989-12-29 | 1990-06-30 | 1990-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-29 | 1994-06-30 | 1994-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-29 | 1998-06-30 | 1998-12-30 | $7700.00 | Window Closed / Lapsed |