US5728492A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mask for projection system using charged particle beam
Assignee: Nikon Corp
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Filing: 1996-05-17
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Granted: 1998-03-17
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Expires: 2016-05-17
Abstract
Abstract A mask is proposed which restrains thermal deformation caused by irradiation by a charged particle beam and thereby increases the accuracy of pattern projection. In order to do this, in this mask for projection system using a charged particle beam according to the present invention, which has a mask base plate which is made from a semiconductor material and which is formed with holes which allow passage of the charged particle beam, at least a specified region around the periphery of the through holes of the mask base plate is covered with a layer of diamond. It is desirable further to cover this diamond layer with a layer of an electroconductive material, in order to prevent static charging up upon it.
Inventors
- 👤 Shintaro Kawata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:59
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/20
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
72 words
A mask for a charged particle projection system comprising: a mask base plate which comprises a diamond layer; and a scattering element, disposed upon said mask base plate defining a pattern, wherein a first characteristic scale for absorption or scattering of a beam of charged particles in said scattering element is larger than a second characteristic scale for absorption or scattering of said beam of charged particles in said mask base plate.
Claim 2
Dependent Claim
72 words
A mask for a charged particle projection system comprising: a mask base plate which comprises a diamond layer; and a scattering element, disposed upon said mask base plate defining a pattern, wherein a first characteristic scale for absorption or scattering of a beam of charged particles in said scattering element is larger than a second characteristic scale for absorption or scattering of said beam of charged particles in said mask base plate.
Claim 3
Dependent Claim
20 words
A mask for a charged particle projection system according to claim 1, wherein said scattering element is made of tungsten.
Claim 4
Dependent Claim
35 words
A mask for a charged particle projection system according to claim 1, further comprising a reinforcement layer which is made from a material other than diamond and which is layered together with said diamond layer.
Claim 5
Dependent Claim
22 words
A mask for a charged particle projection system according to claim 3, wherein said reinforcement layer is made from a semiconductor material.
Claim 6
Dependent Claim
22 words
A mask for a charged particle projection system according to claim 4, wherein said semiconductor material of said reinforcement layer is silicon.
Claim 7
Dependent Claim
29 words
A mask for a charged particle projection system according to claim 5, wherein said diamond layer is formed upon said reinforcement layer by a process of vapor phase deposition.
Claim 8
Dependent Claim
25 words
A mask for a charged particle projection system according to claim 5, further comprising an electrically conducting layer which is layered over said diamond layer.
Claim 9
Dependent Claim
24 words
A mask for a charged particle projection system according to claim 7, wherein said electrically conducting layer is formed from a non-magnetic metallic material.
Claim 10
Dependent Claim
29 words
A mask for a charged particle projection system according to claim 4, wherein said diamond layer is formed upon said reinforcement layer by a process of vapor phase deposition.
Claim 11
Dependent Claim
25 words
A mask for a charged particle projection system according to claim 4, further comprising an electrically conducting layer which is layered over said diamond layer.
Claim 12
Dependent Claim
24 words
A mask for a charged particle projection system according to claim 10, wherein said electrically conducting layer is formed from a non-magnetic metallic material.
Claim 13
Dependent Claim
29 words
A mask for a charged particle projection system according to claim 3, wherein said diamond layer is formed upon said reinforcement layer by a process of vapor phase deposition.
Claim 14
Dependent Claim
25 words
A mask for a charged particle projection system according to claim 3, further comprising an electrically conducting layer which is layered over said diamond layer.
Claim 15
Dependent Claim
24 words
A mask for a charged particle projection system according to claim 13, wherein said electrically conducting layer is formed from a non-magnetic metallic material.
Claim 16
Dependent Claim
25 words
A mask for a charged particle projection system according to claim 1, further comprising an electrically conducting layer which is layered over said diamond layer.
Claim 17
Dependent Claim
24 words
A mask for a charged particle projection system according to claim 15, wherein said electrically conducting layer is formed from a non-magnetic metallic material.
Claim 18
Independent Claim
56 words
A method for manufacturing a mask for a charged particle projection system, comprising the steps of: forming a diamond layer on a surface of a silicon substrate; forming a lattice-shaped reinforcement on a rear surface of said silicon substrate by a lithographic process; and forming a scattering element for a forming pattern on said diamond layer.
Claim 19
Independent Claim
56 words
A method for manufacturing a mask for a charged particle projection system, comprising the steps of: forming a diamond layer on a surface of a silicon substrate; forming a lattice-shaped reinforcement on a rear surface of said silicon substrate by a lithographic process; and forming a scattering element for a forming pattern on said diamond layer.
Claim 20
Dependent Claim
30 words
A method for manufacturing a mask for a charged particle protection system according to claim 17, wherein said step of forming a diamond layer is a vapor phase deposition step.
References Cited (Backward Citations)
US4448865A
Cited
US5279925A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-03-16 | 2001-09-15 | 2002-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-03-16 | 2005-09-15 | 2006-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-03-16 | 2009-09-15 | 2010-03-17 | $7700.00 | Window Closed / Lapsed |