US5684595A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alignment apparatus and exposure apparatus equipped therewith
Assignee: Nikon Corp
•
Filing: 1996-09-26
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Granted: 1997-11-04
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Expires: 2016-09-26
Abstract
Abstract An alignment apparatus for aligning a first object (reticle) with a second object (wafer) when irradiating a projection light on the first object to project a pattern of the first object onto the second object through a projection optical system. The apparatus includes an illumination optical system for illuminating a plurality marks on the second object with an alignment light having a wavelength band different from the projection light, a detection optical system for receiving the alignment light from the illuminated mark through the projection optical system to detect an image of the mark formed by the alignment light, and a compensating optical system arranged within the detection optical system for compensating a chromatic aberration of magnification caused by the projection optical system due to the differences among the wavelengths within the wavelength band of the alignment light.
Inventors
- 👤 Masaki Kato
- 👤 Hideo Mizutani
- 👤 Masashi Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:24
CPC Classifications
G; G03; G03F; G03F9/00; G03F9/70; G03F9/7065; G03F9/7088
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
266 words
An alignment apparatus for achieving an alignment between a first object and a second object when irradiating a projection light on the first object to project a pattern of the first object onto the second object through a projection optical system, said apparatus comprising: an illumination optical system for illuminating a mark formed on said second object with a multiwavelength alignment light having a wavelength bandwidth different from that of said projection light; a detection optical system for receiving a reflected light from said mark illuminated with said alignment light, through said projection optical system, to detect an image of said mark formed by said reflected light; and a compensating optical system arranged within said detection optical system to provide compensation for a chromatic aberration of magnification caused by said projection optical system due to wavelength differences among a plurality of wavelength components within the wavelength bandwidth of said alignment light, wherein said illumination optical system and said detection optical system are movable as a unit relative to said projection optical system, wherein said compensating optical system includes a first compensating optical member and a second compensating optical member, wherein at least one of said first and second compensating optical members is rotatable about an optical axis of said detection optical system, and wherein the amount and direction of occurrence of said chromatic aberration of magnification varied as the result of the unitary movement of said illumination optical system and said detection optical system relative to said projection optical system are compensated for by rotating said first and second compensating optical members relative to each other.
Claim 2
Dependent Claim
266 words
An alignment apparatus for achieving an alignment between a first object and a second object when irradiating a projection light on the first object to project a pattern of the first object onto the second object through a projection optical system, said apparatus comprising: an illumination optical system for illuminating a mark formed on said second object with a multiwavelength alignment light having a wavelength bandwidth different from that of said projection light; a detection optical system for receiving a reflected light from said mark illuminated with said alignment light, through said projection optical system, to detect an image of said mark formed by said reflected light; and a compensating optical system arranged within said detection optical system to provide compensation for a chromatic aberration of magnification caused by said projection optical system due to wavelength differences among a plurality of wavelength components within the wavelength bandwidth of said alignment light, wherein said illumination optical system and said detection optical system are movable as a unit relative to said projection optical system, wherein said compensating optical system includes a first compensating optical member and a second compensating optical member, wherein at least one of said first and second compensating optical members is rotatable about an optical axis of said detection optical system, and wherein the amount and direction of occurrence of said chromatic aberration of magnification varied as the result of the unitary movement of said illumination optical system and said detection optical system relative to said projection optical system are compensated for by rotating said first and second compensating optical members relative to each other.
Claim 3
Dependent Claim
61 words
The alignment apparatus according to claim 1, wherein said detection optical system includes an objective lens and an imaging lens so as to convert said reflected light from said mark into a substantially collimated light beam, passing from said objective lens to said imaging lens, and wherein said compensating optical system is arranged between said objective lens and said imaging lens.
Claim 4
Dependent Claim
17 words
The alignment apparatus according to claim 2, wherein said compensating optical system comprises an optical dispersion member.
Claim 5
Dependent Claim
24 words
The alignment apparatus according to claim 1, wherein said first compensating optical member and said second compensating optical member comprises a direct vision prism.
Claim 6
Dependent Claim
228 words
An exposure apparatus including exposure light supply means for supplying an exposure light to a first object, a projection optical system for projecting a pattern of said first object onto a second object using said exposure light, and an alignment system for achieving an alignment between said first and second objects, the improvement wherein said alignment system comprises: an illumination optical system for illuminating an alignment mark formed on said second object with an alignment light including a plurality of wavelength components different in wavelength from that of said projection light; a detection optical system for receiving a reflected light from said alignment mark illuminated with said alignment light, through said projection optical system, to detect an image of said alignment mark formed by said reflected light; and a compensating optical system for compensating a chromatic aberration of magnification caused by said projection optical system due to the differences in wavelength among said wavelength components of said alignment light, wherein said compensating optical system includes a first compensating optical member and a second compensating optical member, wherein at least one of said first and second compensating optical members is rotatable about an optical axis of said detection optical system, and wherein the amount and direction of compensation of said chromatic aberration of magnification are varied in response to relative rotation of said first and second compensating optical members.
Claim 7
Dependent Claim
228 words
An exposure apparatus including exposure light supply means for supplying an exposure light to a first object, a projection optical system for projecting a pattern of said first object onto a second object using said exposure light, and an alignment system for achieving an alignment between said first and second objects, the improvement wherein said alignment system comprises: an illumination optical system for illuminating an alignment mark formed on said second object with an alignment light including a plurality of wavelength components different in wavelength from that of said projection light; a detection optical system for receiving a reflected light from said alignment mark illuminated with said alignment light, through said projection optical system, to detect an image of said alignment mark formed by said reflected light; and a compensating optical system for compensating a chromatic aberration of magnification caused by said projection optical system due to the differences in wavelength among said wavelength components of said alignment light, wherein said compensating optical system includes a first compensating optical member and a second compensating optical member, wherein at least one of said first and second compensating optical members is rotatable about an optical axis of said detection optical system, and wherein the amount and direction of compensation of said chromatic aberration of magnification are varied in response to relative rotation of said first and second compensating optical members.
Claim 8
Dependent Claim
109 words
The exposure apparatus according to claim 5, wherein said alignment system is movable as a unit relative to said projection optical system, wherein said compensating optical system includes a first compensating optical member and a second compensating optical member, wherein at least one of said first and second compensating optical members is rotatable about an optical axis of said detection optical system, and wherein the amount and direction of occurrence of said chromatic aberration of magnification varying as the result of the relative movement of said alignment system and said projection optical system are compensated for in response to relative rotation of said first and second compensating optical members.
Claim 9
Dependent Claim
103 words
The exposure apparatus according to claim 6, further comprising compensating means for compensating the amount and direction of said chromatic aberration of magnification varying in response to the movement of said alignment system, wherein said compensating means includes first means for detecting a position of said alignment system, second means responsive to an output from said first means to compute an amount of said chromatic aberration of magnification and a direction of compensation of said chromatic aberration of magnification, and third means for driving relative rotation of said first and second compensating optical members in response to an output from said second means.
Claim 10
Dependent Claim
26 words
The exposure apparatus according to claim 6, wherein each of said first compensating optical member and said second compensating optical member comprises an optical dispersion member.
Claim 11
Dependent Claim
62 words
The exposure apparatus according to claim 5, wherein said detection optical system includes an objective lens and an imaging lens so as to convert said reflected light from said alignment mark into a substantially collimated light beam passing from said objective lens to said imaging lens, and wherein said compensating optical system is arranged between said objective lens and said imaging lens.
Claim 12
Dependent Claim
227 words
An exposure apparatus including exposure light supply means for supplying an exposure light to a first object, a projection optical system for projecting a pattern of said first object onto a second object using said exposure light, and an alignment system for achieving an alignment between said first and second objects, the improvement wherein said alignment system comprises: an illumination optical system for illuminating an alignment mark formed on said second object with an alignment light including a plurality of wavelength components different in wavelength from that of said projection light; a detection optical system for receiving a reflected light from said alignment mark illuminated with said alignment light, through said projection optical system, to detect an image of said alignment mark formed by said reflected light; and a compensating optical system for compensating a chromatic aberration of magnification caused by said projection optical system due to the differences in wavelength among said wavelength components of said alignment light, wherein said compensating optical system includes a first compensating optical member and a second compensating optical member, and wherein at least one of said first and second compensating optical members is rotatable about an optical axis of said detection optical system so as to vary the amount of compensation of said chromatic aberration of magnification in response to relative rotation of said first and second compensating optical members.
Claim 13
Dependent Claim
227 words
An exposure apparatus including exposure light supply means for supplying an exposure light to a first object, a projection optical system for projecting a pattern of said first object onto a second object using said exposure light, and an alignment system for achieving an alignment between said first and second objects, the improvement wherein said alignment system comprises: an illumination optical system for illuminating an alignment mark formed on said second object with an alignment light including a plurality of wavelength components different in wavelength from that of said projection light; a detection optical system for receiving a reflected light from said alignment mark illuminated with said alignment light, through said projection optical system, to detect an image of said alignment mark formed by said reflected light; and a compensating optical system for compensating a chromatic aberration of magnification caused by said projection optical system due to the differences in wavelength among said wavelength components of said alignment light, wherein said compensating optical system includes a first compensating optical member and a second compensating optical member, and wherein at least one of said first and second compensating optical members is rotatable about an optical axis of said detection optical system so as to vary the amount of compensation of said chromatic aberration of magnification in response to relative rotation of said first and second compensating optical members.
Claim 14
Dependent Claim
89 words
The exposure apparatus according to claim 10, further comprising compensating means for compensating the amount of said chromatic aberration of magnification varying in response to the movement of said alignment system, wherein said compensating means includes first means for detecting a position of said alignment system, second means responsive to an output from said first means to compute an amount of chromatic aberration of magnification, and third means for driving relative rotation of said first and second compensating optical members in response to an output from said second means.
Claim 15
Dependent Claim
260 words
An alignment apparatus for achieving an alignment between a first object and a second object when irradiating a projection light on said first object to project a pattern of said first object onto said second object through a projection optical system, said apparatus comprising; an illumination optical system for illuminating a mark formed on said second object with a multiwavelength alignment light having a predetermined wavelength bandwidth different from that of said projection light; a detection optical system for receiving a reflected light from said mark illuminated with said alignment light, through said projection optical system, to detect an image of said mark formed by said reflected light; said detection optical system including an objective lens and an imaging lens so as to convert said reflected light from said mark into a substantially collimated light beam passing from said objective lens to said imaging lens; and a compensating optical system arranged between said objective lens and said imaging lens for compensating a chromatic aberration of magnification caused by said projection optical system due to wavelength differences among a plurality of wavelength components within the wavelength bandwidth of said alignment light, wherein said compensating optical system comprises a first compensating optical member and a second compensating optical member, and wherein at least one of said first and second compensating optical members is rotatable about an optical axis of said detection optical system so as to vary the amount and direction of compensation of said chromatic aberration of magnification in response to relative rotation of said first and second compensating optical members.
Claim 16
Dependent Claim
260 words
An alignment apparatus for achieving an alignment between a first object and a second object when irradiating a projection light on said first object to project a pattern of said first object onto said second object through a projection optical system, said apparatus comprising; an illumination optical system for illuminating a mark formed on said second object with a multiwavelength alignment light having a predetermined wavelength bandwidth different from that of said projection light; a detection optical system for receiving a reflected light from said mark illuminated with said alignment light, through said projection optical system, to detect an image of said mark formed by said reflected light; said detection optical system including an objective lens and an imaging lens so as to convert said reflected light from said mark into a substantially collimated light beam passing from said objective lens to said imaging lens; and a compensating optical system arranged between said objective lens and said imaging lens for compensating a chromatic aberration of magnification caused by said projection optical system due to wavelength differences among a plurality of wavelength components within the wavelength bandwidth of said alignment light, wherein said compensating optical system comprises a first compensating optical member and a second compensating optical member, and wherein at least one of said first and second compensating optical members is rotatable about an optical axis of said detection optical system so as to vary the amount and direction of compensation of said chromatic aberration of magnification in response to relative rotation of said first and second compensating optical members.
Claim 17
Dependent Claim
16 words
The alignment apparatus according to claim 12, wherein said compensating optical system comprises optical dispersion member.
Claim 18
Dependent Claim
16 words
The alignment apparatus according to claim 12, wherein said compensating optical system comprises a diffraction grating.
Claim 19
Dependent Claim
17 words
The alignment apparatus according to claim 12, wherein said compensating optical system comprises a direct vision prism.
Claim 20
Dependent Claim
205 words
In an exposure apparatus including an alignment system for detecting relative positions of a first object and a second object when transferring a pattern of said first object onto said second object through a projection optical system, the improvement wherein said alignment system comprises: an illumination optical system for illuminating an alignment mark formed on said second object with an alignment light including a plurality of wavelength components; a detection optical system for detecting said alignment mark on said second object through said projection optical system; and a compensating optical system for compensating a chromatic aberration of magnification caused by said projection optical system due to differences in wavelength among said wavelength components of said alignment light when said alignment mark on said second object is detected by said detecting optical system through said projection optical system, wherein said compensating optical system includes a first compensating optical member and a second compensating optical member, and wherein at least one of said first and second compensating optical members is rotatable about an optical axis of said detection optical system so as to vary the amount of compensation of said chromatic aberration of magnification in response to relative rotation of said first and second compensation optical members.
Claim 21
Dependent Claim
205 words
In an exposure apparatus including an alignment system for detecting relative positions of a first object and a second object when transferring a pattern of said first object onto said second object through a projection optical system, the improvement wherein said alignment system comprises: an illumination optical system for illuminating an alignment mark formed on said second object with an alignment light including a plurality of wavelength components; a detection optical system for detecting said alignment mark on said second object through said projection optical system; and a compensating optical system for compensating a chromatic aberration of magnification caused by said projection optical system due to differences in wavelength among said wavelength components of said alignment light when said alignment mark on said second object is detected by said detecting optical system through said projection optical system, wherein said compensating optical system includes a first compensating optical member and a second compensating optical member, and wherein at least one of said first and second compensating optical members is rotatable about an optical axis of said detection optical system so as to vary the amount of compensation of said chromatic aberration of magnification in response to relative rotation of said first and second compensation optical members.
Claim 22
Dependent Claim
239 words
An alignment apparatus for achieving an alignment between a first object and a second object when irradiating a projection light on the first object to project a pattern of the first object onto the second object through a projection optical system, said apparatus comprising: an illumination optical system for illuminating a mark formed on said second object with a multiwavelength alignment light having a wavelength bandwidth different from that of said projection light; a detection optical system for receiving a reflected light from said mark illuminated with said alignment light, through said projection optical system, to detect an image of said mark formed by said reflected light; and a compensating optical system arranged within said detection optical system to provide compensation for a chromatic aberration of magnification caused by said projection optical system due to wavelength differences among a plurality of wavelength components within the wavelength bandwidth of said alignment light, wherein said illumination optical system and said detection optical system are movable as a unit relative to said projection optical system, wherein said compensating optical system includes a compensating optical member which is rotatable about an optical axis of said detection optical system, and wherein the amount of occurrence of said chromatic aberration of magnification varied as the result of the unitary movement of said illumination optical system and said detection optical system relative to said projection optical system is compensated for by rotating said compensating optical member.
Claim 23
Dependent Claim
239 words
An alignment apparatus for achieving an alignment between a first object and a second object when irradiating a projection light on the first object to project a pattern of the first object onto the second object through a projection optical system, said apparatus comprising: an illumination optical system for illuminating a mark formed on said second object with a multiwavelength alignment light having a wavelength bandwidth different from that of said projection light; a detection optical system for receiving a reflected light from said mark illuminated with said alignment light, through said projection optical system, to detect an image of said mark formed by said reflected light; and a compensating optical system arranged within said detection optical system to provide compensation for a chromatic aberration of magnification caused by said projection optical system due to wavelength differences among a plurality of wavelength components within the wavelength bandwidth of said alignment light, wherein said illumination optical system and said detection optical system are movable as a unit relative to said projection optical system, wherein said compensating optical system includes a compensating optical member which is rotatable about an optical axis of said detection optical system, and wherein the amount of occurrence of said chromatic aberration of magnification varied as the result of the unitary movement of said illumination optical system and said detection optical system relative to said projection optical system is compensated for by rotating said compensating optical member.
Claim 24
Dependent Claim
61 words
The alignment apparatus according to claim 17, wherein said detection optical system includes an objective lens and an imaging lens so as to convert said reflected light from said mark into a substantially collimated light beam passing from said objective lens to said imaging lens, and wherein said compensating optical system is arranged between said objective lens and said imaging lens.
Claim 25
Dependent Claim
17 words
The alignment apparatus according to claim 18, wherein said compensating optical member comprises an optical dispersion member.
Claim 26
Dependent Claim
17 words
The alignment apparatus according to claim 17, wherein said compensating optical member comprises a direct vision prism.
Claim 27
Dependent Claim
193 words
An exposure apparatus including exposure light supply means for supplying an exposure light to a first object, a projection optical system for projecting a pattern of said first object onto a second object using said exposure light, and an alignment system for achieving an alignment between said first and second objects, the improvement wherein said alignment system comprises: an illumination optical system for illuminating an alignment mark formed on said second object with an alignment light including a plurality of wavelength components different in wavelength from that of said projection light; a detection optical system for receiving a reflected light from said alignment mark illuminated with said alignment light, through said projection optical system, to detect an image of said alignment mark formed by said reflected light; and a compensating optical system for compensating a chromatic aberration of magnification caused by said projection optical system due to the differences in wavelength among said wavelength components of said alignment light, is rotatable about an optical axis of said detection optical system, and wherein the amount of compensation of said chromatic aberration of magnification is varied in response to rotation of said compensating optical member.
Claim 28
Dependent Claim
193 words
An exposure apparatus including exposure light supply means for supplying an exposure light to a first object, a projection optical system for projecting a pattern of said first object onto a second object using said exposure light, and an alignment system for achieving an alignment between said first and second objects, the improvement wherein said alignment system comprises: an illumination optical system for illuminating an alignment mark formed on said second object with an alignment light including a plurality of wavelength components different in wavelength from that of said projection light; a detection optical system for receiving a reflected light from said alignment mark illuminated with said alignment light, through said projection optical system, to detect an image of said alignment mark formed by said reflected light; and a compensating optical system for compensating a chromatic aberration of magnification caused by said projection optical system due to the differences in wavelength among said wavelength components of said alignment light, is rotatable about an optical axis of said detection optical system, and wherein the amount of compensation of said chromatic aberration of magnification is varied in response to rotation of said compensating optical member.
Claim 29
Dependent Claim
63 words
The exposure apparatus according to claim 21, wherein said alignment system is movable as a unit relative to said projection optical system, and wherein the amount of occurrence of said chromatic aberration of magnification varying as the result of the relative movement of said alignment system and said projection optical system is compensated for in response to rotation of said compensating optical member.
Claim 30
Dependent Claim
86 words
The exposure apparatus according to claim 22, further comprising compensating means for compensating the amount of said chromatic aberration of magnification varying in response to the movement of said alignment system, wherein said compensating means includes first means for detecting a position of said alignment system, second means responsive to an output from said first means to compute an amount of said chromatic aberration of magnification, and third means for driving rotation of said compensating optical member in response to an output from said second means.
Claim 31
Dependent Claim
209 words
An exposure apparatus including exposure light supply means for supplying an exposure light to a first object, a projection optical system for projecting a pattern of said first object onto a second object using said exposure light, and an alignment system for achieving an alignment between said first and second objects, the improvement wherein said alignment system comprises: an illumination optical system for illuminating an alignment mark formed on said second object with an alignment light including a plurality of wavelength components different in wavelength from that of said projection light; a detection optical system for receiving a reflected light from said alignment mark illuminated with said alignment light, through said projection optical system, to detect an image of said alignment mark formed by said reflected light; and a compensating optical system for compensating a chromatic aberration of magnification caused by said projection optical system due to the differences in wavelength among said wavelength components of said alignment light, wherein said compensating optical system includes a compensating optical member, and wherein said compensating optical member is rotatable about an optical axis of said detection optical system so as to vary the amount of compensation of said chromatic aberration of magnification in response to rotation of said compensating optical member.
Claim 32
Dependent Claim
209 words
An exposure apparatus including exposure light supply means for supplying an exposure light to a first object, a projection optical system for projecting a pattern of said first object onto a second object using said exposure light, and an alignment system for achieving an alignment between said first and second objects, the improvement wherein said alignment system comprises: an illumination optical system for illuminating an alignment mark formed on said second object with an alignment light including a plurality of wavelength components different in wavelength from that of said projection light; a detection optical system for receiving a reflected light from said alignment mark illuminated with said alignment light, through said projection optical system, to detect an image of said alignment mark formed by said reflected light; and a compensating optical system for compensating a chromatic aberration of magnification caused by said projection optical system due to the differences in wavelength among said wavelength components of said alignment light, wherein said compensating optical system includes a compensating optical member, and wherein said compensating optical member is rotatable about an optical axis of said detection optical system so as to vary the amount of compensation of said chromatic aberration of magnification in response to rotation of said compensating optical member.
Claim 33
Dependent Claim
86 words
The exposure apparatus according to claim 24, further comprising compensating means for compensating the amount of said chromatic aberration of magnification varying in response to the movement of said alignment system, wherein said compensating means includes first means for detecting a position of said alignment system, second means responsive to an output from said first means to compute an amount of chromatic aberration of magnification, and third means for driving relative rotation of said compensating optical member in response to an output from said second means.
Claim 34
Dependent Claim
62 words
The exposure apparatus according to claim 24, wherein said detection optical system includes an objective lens and an imaging lens so as to convert said reflected light from said alignment mark into a substantially collimated light beam passing from said objective lens to said imaging lens, and wherein said compensating optical system is arranged between said objective lens and said imaging lens.
Claim 35
Dependent Claim
17 words
The exposure apparatus according to claim 26, wherein said compensating optical member comprises an optical dispersion member.
Claim 36
Dependent Claim
240 words
An alignment apparatus for achieving an alignment between a first object and a second object when irradiating a projection light on said first object to project a pattern of said first object onto said second object through a projection optical system, said apparatus comprising: an illumination optical system for illuminating a mark formed on said second object with a multiwavelength alignment light having a predetermined wavelength bandwidth different from that of said projection light; a detection optical system for receiving a reflected light from said mark illuminated with said alignment light, through said projection optical system, to detect an image of said mark formed by said reflected light; said detection optical system including an objective lens and an imaging lens so as to convert said reflected light from said mark into a substantially collimated light beam passing from said objective lens to said imaging lens; and a compensating optical system arranged between said objective lens and said imaging lens for compensating a chromatic aberration of magnification caused by said projection optical system due to wavelength differences among a plurality of wavelength components within the wavelength bandwidth of said alignment light, wherein said compensating optical system comprises a compensating optical member, and wherein said compensating optical member is rotatable about an optical axis of said detection optical system so as to vary the amount of compensation of said chromatic aberration of magnification in response to rotation of said compensating optical member.
Claim 37
Dependent Claim
240 words
An alignment apparatus for achieving an alignment between a first object and a second object when irradiating a projection light on said first object to project a pattern of said first object onto said second object through a projection optical system, said apparatus comprising: an illumination optical system for illuminating a mark formed on said second object with a multiwavelength alignment light having a predetermined wavelength bandwidth different from that of said projection light; a detection optical system for receiving a reflected light from said mark illuminated with said alignment light, through said projection optical system, to detect an image of said mark formed by said reflected light; said detection optical system including an objective lens and an imaging lens so as to convert said reflected light from said mark into a substantially collimated light beam passing from said objective lens to said imaging lens; and a compensating optical system arranged between said objective lens and said imaging lens for compensating a chromatic aberration of magnification caused by said projection optical system due to wavelength differences among a plurality of wavelength components within the wavelength bandwidth of said alignment light, wherein said compensating optical system comprises a compensating optical member, and wherein said compensating optical member is rotatable about an optical axis of said detection optical system so as to vary the amount of compensation of said chromatic aberration of magnification in response to rotation of said compensating optical member.
Claim 38
Dependent Claim
17 words
The alignment apparatus according to claim 28, wherein said compensating optical member comprises an optical dispersion member.
Claim 39
Dependent Claim
16 words
The alignment apparatus according to claim 28, wherein said compensating optical member comprises a diffraction grating.
Claim 40
Dependent Claim
17 words
The alignment apparatus according to claim 28, wherein said compensating optical member comprises a direct vision prism.
Claim 41
Dependent Claim
187 words
In an exposure apparatus including an alignment system for detecting relative positions of a first object and a second object when transferring a pattern of said first object onto said second object through a projection optical system, the improvement wherein said alignment system comprises: an illumination optical system for illuminating an alignment mark formed on said second object with an alignment light including a plurality of wavelength components; a detection optical system for detecting said alignment mark on said second object through said projection optical system; and a compensating optical system for compensating a chromatic aberration of magnification caused by said projection optical system due to differences in wavelength among said wavelength components of said alignment light when said alignment mark on said second object is detected by said detecting optical system through said projection optical system, wherein said compensating optical system includes a compensating optical member, and wherein said compensating optical member is rotatable about an optical axis of said detection optical system so as to vary the amount of compensation of said chromatic aberration of magnification in response to rotation of said compensating optical member.
Claim 42
Dependent Claim
187 words
In an exposure apparatus including an alignment system for detecting relative positions of a first object and a second object when transferring a pattern of said first object onto said second object through a projection optical system, the improvement wherein said alignment system comprises: an illumination optical system for illuminating an alignment mark formed on said second object with an alignment light including a plurality of wavelength components; a detection optical system for detecting said alignment mark on said second object through said projection optical system; and a compensating optical system for compensating a chromatic aberration of magnification caused by said projection optical system due to differences in wavelength among said wavelength components of said alignment light when said alignment mark on said second object is detected by said detecting optical system through said projection optical system, wherein said compensating optical system includes a compensating optical member, and wherein said compensating optical member is rotatable about an optical axis of said detection optical system so as to vary the amount of compensation of said chromatic aberration of magnification in response to rotation of said compensating optical member.
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