US5805344A
Expired / Lapsed
US
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Projection optical system and projection exposure apparatus
Assignee: Nikon Corp
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Filing: 1996-10-11
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Granted: 1998-09-08
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Expires: 2016-10-11
Abstract
Abstract In the projection optical system that projects an image of the first object onto the second object with a fixed reduction ratio and a projection aligner equipped therewith, said projection optical system comprises, viewed from said first object side, in order of succession, the first group of lenses with positive refractive power, and the second group of lenses virtually consists of afocal system, and the third group of lens with positive refractive power, and if the focal length of the overall system is represented by F, the projection magnification ratio of said projection optical system is represented by B, the distance between said first object and said second object is represented by L, and when a ray from the second object side of said projection optical system that is parallel to the optical axis of said projection optical system is incident on said projection optical system, a distance between a point where an extension on the first object side of said ray intercepts the optical axis and said first object plane is represented by e, and a height of said ray on said first object from the optical axis of said projection optical system, when said ray, coming through said projection optical system, reaches said first object is represented by h, then the following conditions should be satisfied: 1.8≦|F/(B•L)| |h/e|≦3/1000.
Inventors
- 👤 Toshihiro Sasaya
- 👤 Kazuo Ushida
- 👤 Yutaka Suenaga
- 👤 Romeo I. Mercado
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:05
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/20; G03F7/70; G03F7/70216; G03F7/70241; G02; G02B; G02B13/00; G02B13/18; G02B13/22; G02B13/24; G02B9/00; G02B9/12
Claims Analysis
Total Claims: 81
Claim 1
Independent Claim
255 words
A projection optical system that projects an image of an object in an object surface onto an image surface with a predetermined reduction magnification comprising, in light path order from said object surface: a first group of lenses with positive refractive power, said first group including at least two positive lenses; a second group of lenses forming an approximately afocal system, said second group including, in light path order from said object surface, a first subgroup of lenses with negative refractive power, said first subgroup including at least two negative lenses, a second subgroup of lenses with positive refractive power, said second subgroup including at least four positive lenses, and a third subgroup of lenses with negative refractive power, said third subgroup including at least two negative lenses; and a third group of lenses with positive refractive power, said third group including at least two positive lenses; wherein: said projection optical system has an optical axis, said projection optical system has a focal length F, said projection optical system has a projection magnification B, said object surface and said image surface are separated by a distance L, a ray from said image surface that is parallel to said optical axis and is incident on said projection optical system emerges from said projection optical system along a path and encounters said object surface at a height h from said optical axis, said ray has an extension along said path, which extension crosses said optical axis at a distance e from said object surface, 1.8≦|F/(B·L)|, and |h/e|≦3/1000.
Claim 2
Dependent Claim
255 words
A projection optical system that projects an image of an object in an object surface onto an image surface with a predetermined reduction magnification comprising, in light path order from said object surface: a first group of lenses with positive refractive power, said first group including at least two positive lenses; a second group of lenses forming an approximately afocal system, said second group including, in light path order from said object surface, a first subgroup of lenses with negative refractive power, said first subgroup including at least two negative lenses, a second subgroup of lenses with positive refractive power, said second subgroup including at least four positive lenses, and a third subgroup of lenses with negative refractive power, said third subgroup including at least two negative lenses; and a third group of lenses with positive refractive power, said third group including at least two positive lenses; wherein: said projection optical system has an optical axis, said projection optical system has a focal length F, said projection optical system has a projection magnification B, said object surface and said image surface are separated by a distance L, a ray from said image surface that is parallel to said optical axis and is incident on said projection optical system emerges from said projection optical system along a path and encounters said object surface at a height h from said optical axis, said ray has an extension along said path, which extension crosses said optical axis at a distance e from said object surface, 1.8≦|F/(B·L)|, and |h/e|≦3/1000.
Claim 3
Dependent Claim
24 words
The projection optical system of claim 1 wherein: a maximum height of the object from said optical axis is represented by H; and |B•H/F|≦8/1000.
Claim 4
Dependent Claim
10 words
The projection optical system of claim 2 wherein: F•h/(B•H•e)≦4. 4.
Claim 5
Dependent Claim
36 words
The projection optical system of claim 3 wherein: said first group of lenses has a focal length f 1 ; said third group of lenses has a focal length f 3 ; and 0.80≦|f.sub.3 /f.sub.1 |≦1.5.
Claim 6
Dependent Claim
10 words
The projection optical system of claim 4 wherein: 0.05≦f.sub.1 /L≦0.3.
Claim 7
Dependent Claim
9 words
The projection optical system of claim 5 wherein: 0.03≦H/L≦0.2.
Claim 8
Dependent Claim
24 words
The projection optical system of claim 1 wherein at least one of said first, second, and third groups of lenses includes an aspherical lens.
Claim 9
Dependent Claim
36 words
The projection optical system of claim 1 wherein: said first subgroup of lenses has a focal length f 21 ; said second subgroup of lenses has a focal length f 22 ; and 1.5≦|f.sub.22 /f.sub.21 |≦5.
Claim 10
Dependent Claim
23 words
The projection optical system of claim 1 wherein: said third subgroup of lenses has a focal length f 23 ; and 0.02≦|f.sub.23 /L|≦0.10.
Claim 11
Dependent Claim
48 words
The projection optical system of claim 9 wherein: said first group of lenses, said first subgroup of lenses in said second group of lenses, and said second subgroup of lenses in said second group of lenses have a composite focal length f a ; and 4≦|f.sub.a /f.sub.23 |.
Claim 12
Dependent Claim
37 words
The projection optical system of claim 10 wherein: the i th subgroup of lenses of said second group of lenses, in light path order from said object surface, has a focal length f 2i ; and -50≦(L/f.sub.1)+(L/f.sub.3)+Σ(L/f.sub.2i)≦0.5.
Claim 13
Dependent Claim
19 words
The projection optical system of claim 1 wherein:: said second subgroup of lenses comprises at least two biconcave lenses.
Claim 14
Dependent Claim
125 words
The projection optical system of claim 12 wherein: the paraxial marginal ray from the axial object point on said object surface enters said first group of lenses at an angle of incidence u 1 ; the paraxial marginal ray from the axial object point on said object surface enters said second group of lenses at an angle of incidence u 2 ; the paraxial marginal ray from the axial object point on said object surface emerges from said second group of lenses at an angle of emergence u 2 '; the paraxial marginal ray from the axial object point on said object surface emerges from said third group of lenses at an angle of emergence U 3 '; |u.sub.2 /u.sub.1 |≦0.5; and |u.sub.2 '/u.sub.3 '|≦0.5.
Claim 15
Dependent Claim
39 words
The projection optical system of claim 13 wherein: said second group of lenses has a focal length f 2 ; said third group of lenses has a focal length f 3 ; |f.sub.2 |/f.sub.1 >1; and |f.sub.2 |/f.sub.3 >1.
Claim 16
Dependent Claim
24 words
The projection optical system of claim 1 wherein said second group of lenses further comprises a fourth subgroup of lenses with positive refractive power.
Claim 17
Dependent Claim
19 words
The projection optical system of claim 15 wherein said fourth subgroup of lenses comprises at least two positive lenses.
Claim 18
Dependent Claim
36 words
The projection optical system of claim 1 wherein: said first group of lenses has a focal length f 1 ; said third group of lenses has a focal length f 3 ; and 0.80≦|f.sub.3 /f.sub.1 |≦1.5.
Claim 19
Dependent Claim
11 words
The projection optical system of claim 17 wherein: 0.05≦f.sub.1 /L≦0.3. 19.
Claim 20
Dependent Claim
24 words
The projection optical system of claim 18 wherein: a maximum height of the object from said optical axis is represented by H; and 0.03≦H/L≦0.2.
Claim 21
Dependent Claim
23 words
The projection optical system of claim 8 wherein: said third subgroup of lenses has a focal length f 23 ; and 0.02≦|f.sub.23 /L|≦0.10.
Claim 22
Dependent Claim
48 words
The projection optical system of claim 20 wherein: said first group of lenses, said first subgroup of lenses in said second group of lenses, and said second subgroup of lenses in said second group of lenses have a composite focal length f a ; and 4≦|f.sub.a /f.sub.23 |.
Claim 23
Dependent Claim
37 words
The projection optical system of claim 21 wherein: the i th subgroup of lenses of said second group of lenses, in light path order from said object surface, has a focal length f 2i ; and -50≦(L/f.sub.1)+(L/f.sub.1)+Σ(L/f.sub.2i)≦0.5.
Claim 24
Dependent Claim
45 words
The projection optical system of claim 1 wherein: said first group of lenses, said first subgroup of lenses in said second group of lenses, and said second subgroup of lenses in said second group of lenses have a composite focal length fa; and 4≦|fa/f.sub.23 |.
Claim 25
Dependent Claim
39 words
The projection optical system of claim 23 wherein: the i th subgroup of lenses of said second group of lenses, in light path order from said object surface, has a focal length f 2i ; and -50≦(L/f.sub.1)+(L/f.sub.3)+Σ(L/f.sub.2i) ≦0.5. 25.
Claim 26
Dependent Claim
37 words
The projection optical system of claim 1 wherein: the i th subgroup of lenses of said second group of lenses, in light path order from said object surface, has a focal length f 21 ; and -50≦(L/f.sub.1)+(L/f.sub.3)+Σ(L/f.sub.2i)≦0.5.
Claim 27
Dependent Claim
67 words
An exposure method for exposing a predetermined pattern formed on a mask onto a substrate by using the projection optical system of claim 1, the method comprising the steps of: illuminating the mask in said object surface with light of a predetermined exposure wavelength; and projecting an image of said pattern formed on said mask onto said substrate in said image surface through said projection optical system.
Claim 28
Dependent Claim
19 words
The exposure method of claim 26 wherein said predetermined pattern formed on said mask is an integrated circuit pattern.
Claim 29
Dependent Claim
67 words
An exposure method for exposing a predetermined pattern formed on a mask onto a substrate by using the projection optical system of claim 6, the method comprising the steps of: illuminating the mask in said object surface with light of a predetermined exposure wavelength; and projecting an image of said pattern formed on said mask onto said substrate in said image surface through said projection optical system.
Claim 30
Dependent Claim
19 words
The exposure method of claim 28 wherein said predetermined pattern formed on said mask is an integrated circuit pattern.
Claim 31
Dependent Claim
67 words
An exposure method for exposing a predetermined pattern formed on a mask onto a substrate by using the projection optical system of claim 11, the method comprising the steps of: illuminating the mask in said object surface with light of a predetermined exposure wavelength; and projecting an image of said pattern formed on said mask onto said substrate in said image surface through said projection optical system.
Claim 32
Dependent Claim
19 words
The exposure method of claim 30 wherein said predetermined pattern formed on said mask is an integrated circuit pattern.
Claim 33
Dependent Claim
67 words
An exposure method for exposing a predetermined pattern formed on a mask onto a substrate by using the projection optical system of claim 14, the method comprising the steps of: illuminating the mask in said object surface with light of a predetermined exposure wavelength; and projecting an image of said pattern formed on said mask onto said substrate in said image surface through said projection optical system.
Claim 34
Dependent Claim
19 words
The exposure method of claim 32 wherein said predetermined pattern formed on said mask is an integrated circuit pattern.
Claim 35
Dependent Claim
67 words
An exposure method for exposing a predetermined pattern formed on a mask onto a substrate by using the projection optical system of claim 16, the method comprising the steps of: illuminating the mask in said object surface with light of a predetermined exposure wavelength; and projecting an image of said pattern formed on said mask onto said substrate in said image surface through said projection optical system.
Claim 36
Dependent Claim
19 words
The exposure method of claim 34 wherein said predetermined pattern formed on said mask is an integrated circuit pattern.
Claim 37
Dependent Claim
67 words
An exposure method for exposing a predetermined pattern formed on a mask onto a substrate by using the projection optical system of claim 19, the method comprising the steps of: illuminating the mask in said object surface with light of a predetermined exposure wavelength; and projecting an image of said pattern formed on said mask onto said substrate in said image surface through said projection optical system.
Claim 38
Dependent Claim
19 words
The exposure method of claim 36 wherein said predetermined pattern formed on said mask is an integrated circuit pattern.
Claim 39
Dependent Claim
67 words
An exposure method for exposing a predetermined pattern formed on a mask onto a substrate by using the projection optical system of claim 22, the method comprising the steps of: illuminating the mask in said object surface with light of a predetermined exposure wavelength; and projecting an image of said pattern formed on said mask onto said substrate in said image surface through said projection optical system.
Claim 40
Dependent Claim
19 words
The exposure method of claim 38 wherein said predetermined pattern formed on said mask is an integrated circuit pattern.
Claim 41
Dependent Claim
67 words
An exposure method for exposing a predetermined pattern formed on a mask onto a substrate by using the projection optical system of claim 24, the method comprising the steps of: illuminating the mask in said object surface with light of a predetermined exposure wavelength; and projecting an image of said pattern formed on said mask onto said substrate in said image surface through said projection optical system.
Claim 42
Dependent Claim
19 words
The exposure method of claim 40 wherein said predetermined pattern formed on said mask is an integrated circuit pattern.
Claim 43
Dependent Claim
67 words
An exposure method for exposing a predetermined pattern formed on a mask onto a substrate by using the projection optical system of claim 7, the method comprising the steps of: illuminating the mask in said object surface with light of a predetermined exposure wavelength; and projecting an image of said pattern formed on said mask onto said substrate in said image surface through said projection optical system.
Claim 44
Dependent Claim
19 words
The exposure method of claim 42 wherein said predetermined pattern formed on said mask is an integrated circuit pattern.
Claim 45
Dependent Claim
293 words
Exposure apparatus comprising: an illumination system that illuminates a first object having an object surface on which a fixed pattern is formed; a projection optical system which projects an image of said fixed pattern onto an image surface on a second object; a first supporting unit that supports said first object; a second supporting unit that supports said second object; and said projection optical system comprising, in light path order from said object surface: a first group of lenses with positive refractive power, said first group including at least two positive lenses; a second group of lenses forming an approximately afocal system, said second group including, in light path order from said object surface, a first subgroup of lenses with negative refractive power, said first subgroup including at least two negative lenses, a second subgroup of lenses with positive refractive power, said second subgroup including at least four positive lenses, and a third subgroup of lenses with negative refractive power, said third subgroup including at least two negative lenses; and a third group of lenses with positive refractive power, said third group including at least two positive lenses; wherein: said projection optical system has an optical axis, said projection optical system has a focal length F. said projection optical system has a projection magnification B, said object surface and said image surface are separated by a distance L, a ray from said image surface that is parallel to said optical axis and is incident on said projection optical system emerges from said projection optical system along a path and encounters said object surface at a height h from said optical axis, said ray has an extension along said path, which extension crosses said optical axis at a distance e from said object surface,
Claim 46
Dependent Claim
293 words
Exposure apparatus comprising: an illumination system that illuminates a first object having an object surface on which a fixed pattern is formed; a projection optical system which projects an image of said fixed pattern onto an image surface on a second object; a first supporting unit that supports said first object; a second supporting unit that supports said second object; and said projection optical system comprising, in light path order from said object surface: a first group of lenses with positive refractive power, said first group including at least two positive lenses; a second group of lenses forming an approximately afocal system, said second group including, in light path order from said object surface, a first subgroup of lenses with negative refractive power, said first subgroup including at least two negative lenses, a second subgroup of lenses with positive refractive power, said second subgroup including at least four positive lenses, and a third subgroup of lenses with negative refractive power, said third subgroup including at least two negative lenses; and a third group of lenses with positive refractive power, said third group including at least two positive lenses; wherein: said projection optical system has an optical axis, said projection optical system has a focal length F. said projection optical system has a projection magnification B, said object surface and said image surface are separated by a distance L, a ray from said image surface that is parallel to said optical axis and is incident on said projection optical system emerges from said projection optical system along a path and encounters said object surface at a height h from said optical axis, said ray has an extension along said path, which extension crosses said optical axis at a distance e from said object surface,
Claim 47
Dependent Claim
3 words
8≦|F/(B·L)|, and |h/e|≦3/1000.
Claim 48
Dependent Claim
3 words
8≦|F/(B·L)|, and |h/e|≦3/1000.
Claim 49
Dependent Claim
23 words
The exposure apparatus of claim 44 wherein said second group of lenses further comprises a fourth subgroup of lenses with positive refractive power.
Claim 50
Dependent Claim
18 words
The exposure apparatus of claim 45 wherein said fourth subgroup of lenses comprises at least two positive lenses.
Claim 51
Dependent Claim
23 words
The exposure apparatus of claim 44 wherein: a maximum height of the object from said optical axis is represented by H; and |B•H/F|≦8/1000.
Claim 52
Dependent Claim
8 words
The exposure apparatus of claim 44 wherein: F•h/(B•H•e)≦4.
Claim 53
Dependent Claim
30 words
The exposure apparatus of claim 44 wherein: said first group of lenses has a focal length f1; said third group of lenses has a focal length f3; and 0.80≦|f3/f1|≦1.5. 50.
Claim 54
Dependent Claim
10 words
The exposure apparatus of claim 44 wherein: 0.05≦f 1 /L≦0.3.
Claim 55
Dependent Claim
8 words
The exposure apparatus of claim 44 wherein: 0.03≦H/L≦0.2.
Claim 56
Dependent Claim
28 words
The exposure apparatus of claim 44 wherein at least one of said first, second, and third groups of lenses in said projection optical system includes an aspherical lens.
Claim 57
Dependent Claim
164 words
A projection optical system that projects an image of an object in an object surface onto an image surface with a predetermined reduction magnification comprising, in light path order from said object surface: a first group of lenses with positive refractive power, said first group including at least two positive lenses; a second group of lenses forming an approximately afocal system, said second group including, in light path order from said object surface, a first subgroup of lenses with negative refractive power, said first subgroup including at least two negative lenses, a second subgroup of lenses with positive refractive power, said second subgroup including at least four positive lenses, and a third subgroup of lenses with negative refractive power, said third subgroup including at least two negative lenses; and a third group of lenses with positive refractive power, said third group including at least two positive lenses; wherein at least one of said first, second, and third groups of lenses includes an aspherical lens.
Claim 58
Dependent Claim
164 words
A projection optical system that projects an image of an object in an object surface onto an image surface with a predetermined reduction magnification comprising, in light path order from said object surface: a first group of lenses with positive refractive power, said first group including at least two positive lenses; a second group of lenses forming an approximately afocal system, said second group including, in light path order from said object surface, a first subgroup of lenses with negative refractive power, said first subgroup including at least two negative lenses, a second subgroup of lenses with positive refractive power, said second subgroup including at least four positive lenses, and a third subgroup of lenses with negative refractive power, said third subgroup including at least two negative lenses; and a third group of lenses with positive refractive power, said third group including at least two positive lenses; wherein at least one of said first, second, and third groups of lenses includes an aspherical lens.
Claim 59
Dependent Claim
68 words
An exposure method for exposing a predetermined pattern formed on a mask onto a substrate by using the projection optical system according to claim 53, the method comprising the steps of: illuminating the mask in said object surface with light of a predetermined exposure wavelength; and projecting an image of said pattern formed on said mask onto said substrate in said image surface through said projection optical system.
Claim 60
Dependent Claim
19 words
The exposure method of claim 54 wherein said predetermined pattern formed on said mask is an integrated circuit pattern.
Claim 61
Dependent Claim
67 words
Exposure apparatus comprising the projection optical system according to claim 53 for exposing a predetermined pattern formed on a mask onto a substrate through the projection optical system, the exposure apparatus comprising: an illumination system that illuminates the mask in said object surface with light of a predetermined exposure wavelength; a first supporting unit that supports said mask; and a second supporting unit that supports said substrate.
Claim 62
Dependent Claim
33 words
The projection optical system of claim 53 wherein said second group of lenses further comprises a fourth subgroup of lenses with positive refractive power, said fourth subgroup including at least two positive lenses.
Claim 63
Dependent Claim
68 words
An exposure method for exposing a predetermined pattern formed on a mask onto a substrate by using the projection optical system according to claim 57, the method comprising the steps of: illuminating the mask in said object surface with light of a predetermined exposure wavelength; and projecting an image of said pattern formed on said mask onto said substrate in said image surface through said projection optical system.
Claim 64
Dependent Claim
19 words
The exposure method of claim 58 wherein said predetermined pattern formed on said mask is an integrated circuit pattern.
Claim 65
Dependent Claim
67 words
Exposure apparatus comprising the projection optical system according to claim 57 for exposing a predetermined pattern formed on a mask onto a substrate through the projection optical system, the exposure apparatus comprising: an illumination system that illuminates the mask in said object surface with light of a predetermined exposure wavelength; a first supporting unit that supports said mask; and a second supporting unit that supports said substrate.
Claim 66
Dependent Claim
37 words
The projection optical system of claim 57 wherein: said object surface and said image surface are separated by a distance L; said first group of lenses has a focal length f 1 ; and 0.05≦f 1 /L≦0.3.
Claim 67
Dependent Claim
68 words
An exposure method for exposing a predetermined pattern formed on a mask onto a substrate by using the projection optical system according to claim 61, the method comprising the steps of: illuminating the mask in said object surface with light of a predetermined exposure wavelength; and projecting an image of said pattern formed on said mask onto said substrate in said image surface through said projection optical system.
Claim 68
Dependent Claim
19 words
The exposure method of claim 62 wherein said predetermined pattern formed on said mask is an integrated circuit pattern.
Claim 69
Dependent Claim
67 words
Exposure apparatus comprising the projection optical system according to claim 61 for exposing a predetermined pattern formed on a mask onto a substrate through the projection optical system, the exposure apparatus comprising: an illumination system that illuminates the mask in said object surface with light of a predetermined exposure wavelength; a first supporting unit that supports said mask; and a second supporting unit that supports said substrate.
Claim 70
Dependent Claim
40 words
The projection optical system of claim 53, wherein: said aspherical lens has a rotationally symmetric aspherical surface with respect to an optical axis of said aspherical lens; and said rotationally symmetric aspherical surface is formed as a consecutive refractive surface.
Claim 71
Dependent Claim
68 words
An exposure method for exposing a predetermined pattern formed on a mask onto a substrate by using the projection optical system according to claim 65, the method comprising the steps of: illuminating the mask in said object surface with light of a predetermined exposure wavelength; and projecting an image of said pattern formed on said mask onto said substrate in said image surface through said projection optical system.
Claim 72
Dependent Claim
19 words
The exposure method of claim 66 wherein said predetermined pattern formed on said mask is an integrated circuit pattern.
Claim 73
Dependent Claim
67 words
Exposure apparatus comprising the projection optical system according to claim 65 for exposing a predetermined pattern formed on a mask onto a substrate through the projection optical system, the exposure apparatus comprising: an illumination system that illuminates the mask in said object surface with light of a predetermined exposure wavelength; a first supporting unit that supports said mask; and a second supporting unit that supports said substrate.
Claim 74
Dependent Claim
36 words
The projection optical system of claim 65, wherein: said first subgroup of lenses has a focal length f 21 ; said second subgroup of lenses has a focal length f 22 ; and 1.5≦|f.sub.22 /f.sub.21 |≦5.
Claim 75
Dependent Claim
68 words
An exposure method for exposing a predetermined pattern formed on a mask onto a substrate by using the projection optical system according to claim 69, the method comprising the steps of: illuminating the mask in said object surface with light of a predetermined exposure wavelength; and projecting an image of said pattern formed on said mask onto said substrate in said image surface through said projection optical system.
Claim 76
Dependent Claim
19 words
The exposure method of claim 70 wherein said predetermined pattern formed on said mask is an integrated circuit pattern.
Claim 77
Dependent Claim
67 words
Exposure apparatus comprising the projection optical system according to claim 69 for exposing a predetermined pattern formed on a mask onto a substrate through the projection optical system, the exposure apparatus comprising: an illumination system that illuminates the mask in said object surface with light of a predetermined exposure wavelength; a first supporting unit that supports said mask; and a second supporting unit that supports said substrate.
Claim 78
Dependent Claim
36 words
The projection optical system of claim 69, wherein: said first group of lenses has a focal length f 1 ; said object surface and said image surface are separated by a distance L; and 0.05≦f.sub.1 /L≦0.3.
Claim 79
Dependent Claim
68 words
An exposure method for exposing a predetermined pattern formed on a mask onto a substrate by using the projection optical system according to claim 73, the method comprising the steps of: illuminating the mask in said object surface with light of a predetermined exposure wavelength; and projecting an image of said pattern formed on said mask onto said substrate in said image surface through said projection optical system.
Claim 80
Dependent Claim
19 words
The exposure method of claim 74 wherein said predetermined pattern formed on said mask is an integrated circuit pattern.
Claim 81
Dependent Claim
67 words
Exposure apparatus comprising the projection optical system according to claim 73 for exposing a predetermined pattern formed on a mask onto a substrate through the projection optical system, the exposure apparatus comprising: an illumination system that illuminates the mask in said object surface with light of a predetermined exposure wavelength; a first supporting unit that supports said mask; and a second supporting unit that supports said substrate.
References Cited (Backward Citations)
US4386828A
Cited
JPS5878115A
Cited
US4592625A
Cited
EP0243950A2
Cited
JPS63118115A
Cited
JPS6419317A
Cited
JPH04157412A
Cited
US5260832A
Cited
US5448408A
Cited
JPH05173065A
Cited
JPH07140385A
Cited
JPH07140384A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-09-07 | 2002-03-09 | 2002-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-07 | 2006-03-09 | 2006-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-07 | 2010-03-09 | 2010-09-08 | $7700.00 | Window Closed / Lapsed |