US4870452A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Projection exposure apparatus
Assignee: Nikon Corp
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Filing: 1988-07-01
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Granted: 1989-09-26
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Expires: 2008-07-01
Abstract
Abstract A projection exposure apparatus is provided with an optical member, capable of transmitting the exposure light of a first wavelength, placed between a projection optical system and a wafer. The alignment light of a second wavelength for pattern detection is introduced obliquely to the wafer surface through the optical member. A pattern in the projection exposure area or in the vicinity thereof, particularly an alignment mark can be detected by means of the reflection and transmission characteristics.
Inventors
- 👤 Akikazu Tanimoto
- 👤 Issei Tanaka
- 👤 Akira Miyaji
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:29
CPC Classifications
G; G03; G03F; G03F9/00; G03F9/70; G03F9/7073; G03F9/7076; G03F9/7049
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
131 words
A projection exposure apparatus comprising: a projection optical system for projecting the image of an object on a first plane onto a work piece on a second plane: first radiation means for emitting the light of a first wavelength for illuminating said object; an optical member positioned between said projection optical system and said second plane, and having a portion transmitting the light of said first wavelength emitted from said projection optical system toward said second plane; second radiation means for emitting the light of a second wavelength, different from said first wavelength, obliquely to said second plane through said optical member; and detector means for receiving the light of said second wavelength, which is obliquely emitted from the work piece on said second plane and passes through said optical member.
Claim 2
Dependent Claim
131 words
A projection exposure apparatus comprising: a projection optical system for projecting the image of an object on a first plane onto a work piece on a second plane: first radiation means for emitting the light of a first wavelength for illuminating said object; an optical member positioned between said projection optical system and said second plane, and having a portion transmitting the light of said first wavelength emitted from said projection optical system toward said second plane; second radiation means for emitting the light of a second wavelength, different from said first wavelength, obliquely to said second plane through said optical member; and detector means for receiving the light of said second wavelength, which is obliquely emitted from the work piece on said second plane and passes through said optical member.
Claim 3
Dependent Claim
34 words
A projection exposure apparatus according to claim 1, wherein said optical member is provided with a light control layer showing mutually different reflection and transmission characteristics for said lights of first and second wavelengths.
Claim 4
Dependent Claim
23 words
A projection exposure apparatus according to claim 1, wherein said optical member is positioned across the optical axis of said projection optical system.
Claim 5
Dependent Claim
39 words
A projection exposure apparatus according to claim 1, wherein said second radiation means is adapted to emit the light of said second wavelength from a position between said projection optical system and said second plane into said optical member.
Claim 6
Dependent Claim
36 words
A projection exposure apparatus according to claim 4, wherein said second radiation means is adapted to form a light spot of said second wavelength in the field of said projection optical system on said second plane.
Claim 7
Dependent Claim
30 words
A projection exposure apparatus according to claim 1, wherein said optical member comprises a flat plate with parallel surfaces positioned perpendicular to the optical axis of said projection optical system.
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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) | 1992-09-25 | 1993-03-27 | 1993-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-25 | 1997-03-27 | 1997-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-25 | 2001-03-27 | 2001-09-26 | $7700.00 | Window Closed / Lapsed |