EP0964282A2
Expired / Lapsed
EP
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Projection exposure apparatus with a catadioptric projection optical system
Assignee: Nikon Corp
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Filing: 1999-06-11
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Granted: —
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Expires: 2019-06-11
Abstract
Abstract A projection exposure apparatus (10) for forming an image of a pattern present on a first object such as a reticle (R) onto a second object, such as a wafer (W). The apparatus comprises along three optical axes (AZ1, AX, AZ2), an illumination optical system capable of illuminating the reticle with partially polarized light, and a catadioptric projection optical system (40-70) arranged adjacent the reticle and opposite the illumination optical system. The catadioptric projection optical system comprises one or more substantially spherical mirrors (48), a plurality of refractive members (42, 48, 72, 74), and one or more plane mirrors (60, 66). The plane mirrors are designed and arranged so as to allow a substantially unpolarized image of the reticle pattern, which is illuminated with partially polarized light, to be formed on the wafer. <IMAGE>
Inventors
- 👤 Yasuhiro c/o Nikon Corp. Fuji Bldg. Omura
- 👤 Toshihiko c/o Nikon Corp. Fuji Bldg. Ozawa
- 👤 Takashi c/o Nikon Corp. Fuji Bldg. Mori
- 👤 Hideki c/o Nikon Corp. Fuji Bldg. Komatsuda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 13:48
CPC Classifications
G; G02; G02B; G02B17/00; G02B17/08; G02B17/0892; G02B13/00; G02B13/14; G02B13/143; G03; G03F; G03F7/00; G03F7/70; G03F7/70058; G03F7/70091; G03F7/70108; G03F7/70216; G03F7/70225; G03F7/70275; G03F7/70483; G03F7/7055; G03F7/70566
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
100 words
A projection exposure apparatus for forming an image of a pattern present on a reticle
onto an object, comprising along an optical axis: a) an illumination optical system capable of illuminating the reticle with partially
polarized light; and b) a catadioptric projection optical system arranged adjacent the reticle and
opposite said illumination optical system, said catadioptric projection optical
system comprising one or more substantially spherical mirrors, a plurality of
refractive members, and one or more plane mirrors, said plane mirrors
designed and arranged so as to allow a substantially unpolarized image of the
pattern to be formed on the object.
Claim 2
Dependent Claim
43 words
A projection exposure apparatus according to claim 1, wherein said partially polarized
light includes P-polarized light, wherein the direction of polarization is stipulated
based upon a ray parallel to the optical axis and incident any one of said one or more
plane mirrors.
Claim 3
Dependent Claim
79 words
A projection exposure apparatus according to claim 1, wherein each of said one or
more plane mirrors has a reflectance R p with respect to P-polarized light, a
reflectance R s with respect to S-polarized light, a difference ΔR between
reflectance R p and reflectance R s , a maximum value ΔR max and a minimum value
of ΔR min for ΔR, and wherein the projection exposure apparatus satisfies the
following condition: ΔR max - ΔR min ≤ 0.1
Claim 4
Dependent Claim
87 words
A projection exposure apparatus according to claim 1, further including: a) an off-axis illumination region having a first long dimension within which the
pattern is illuminated by said illumination optical system; b) an off-axis exposure region having a second long dimension within which the
pattern image is formed by said projection optical system on the
photosensitive surface; and c) a reticle stage and a wafer stage for synchronously scanning said illumination
region and exposure region in a direction perpendicular to said first and second
long dimensions, respectively.
Claim 5
Dependent Claim
54 words
A projection exposure apparatus according to claim 1, wherein said projection optical
system includes a first imaging optical system that forms an intermediate image of the
pattern in the vicinity of any one of said one or more plane mirrors, and a second
imaging optical system that reimages said intermediate image onto the object.
Claim 6
Dependent Claim
29 words
A projection exposure apparatus according to claim 5, wherein said first imaging
optical system has one concave mirror, and said second imaging optical system has a
reduction imaging magnification.
Claim 7
Dependent Claim
35 words
A projection exposure apparatus according to claim 5, wherein said projection optical
system includes a second plane mirror arranged objectwise of said one of said one or
more plane mirrors closest to said intermediate image.
Claim 8
Dependent Claim
35 words
A projection exposure apparatus according to claim 6, wherein said projection optical
system includes a second plane mirror arranged objectwise of said one of said one or
more plane mirrors closest to said intermediate image.
Claim 9
Dependent Claim
25 words
A projection exposure apparatus according to claim 5, wherein said projection optical
system includes a second plane mirror arranged within said second imaging optical
system.
Claim 10
Dependent Claim
25 words
A projection exposure apparatus according to claim 6, wherein said projection optical
system includes a second plane mirror arranged within said second imaging optical
system.
Claim 11
Dependent Claim
29 words
A projection exposure apparatus according to claim 1, further including an angle-deviating
prism, arranged in said illumination optical system, capable of adjusting the
polarization of said partially polarized light.
Claim 12
Dependent Claim
24 words
A projection exposure apparatus according to claim 11, wherein said angle deviating
prism comprises a first birefringent optical member and an isotropic optical prism.
Claim 13
Independent Claim
109 words
A method of forming a substantially unpolarized image of a first object illuminated
with partially polarized light, comprising the steps of: a) illuminating the first object with partially polarized light, thereby forming a
partially polarized light beam having first and second polarization components
with different respective intensities; b) directing said light beam through a projection optical system having a plane
mirror system with a first reflectance corresponding to said first polarization
component and a second reflectance corresponding to said second polarization
component; and c) reflecting said light beam from said plane mirror system so as to cause said
first and second polarization components to have substantially the same
intensity.
Claim 14
Dependent Claim
31 words
A method according to claim 13, wherein in said step c), said reflecting step includes
performing one or more reflections from one or more plane mirrors in said plane
mirror system.
Claim 15
Dependent Claim
20 words
A method according to claim 13, further including the step of forming the
substantially unpolarized image on a second object.
Claim 16
Dependent Claim
28 words
A method according to claim 15, wherein the first object and said second object are
simultaneously scanned, thereby forming a substantially unpolarized scanned image
on said second object.
Claim 17
Dependent Claim
23 words
A method according to claim 13, wherein said step a) further includes the step of
adjusting the polarization of said partially polarized light.
Claim 18
Dependent Claim
55 words
A projection exposure apparatus for exposing a pattern present on
a reticle onto a photosensitive substrate, comprising: (a) an illumination optical system capable of illuminating the
reticle with partially polarized light; and (b) a projection optical system arranged between the reticle and
the photosensitive substrate, said projection optical system comprising
a plurality of optical elements.
Claim 19
Dependent Claim
33 words
A projection exposure apparatus according to claim 18, wherein at
least one of said optical elements design to form a substantially
unpolarized image of the pattern to be formed on the photosensitive
substrate.
Claim 20
Dependent Claim
69 words
A projection exposure apparatus according to claim 18, further
comprising a correcting optical system disposed at a predetermined
optical path of the illumination optical system ; wherein the correcting optical system capable of forming the
partially polarized light so as to correct an operation caused by at
least one of said optical elements and form a substantially unpolarized
image of the pattern to be formed on the photosensitive substrate.
Claim 21
Dependent Claim
18 words
A projection exposure apparatus according to claim 18, wherein the
projection optical system includes a catadioptic optical system.
Claim 22
Dependent Claim
21 words
A projection exposure apparatus according to claim 19, wherein
said at least one of said optical elements includes a plane mirror.
Claim 23
Dependent Claim
21 words
A projection exposure apparatus according to claim 20, wherein
said at least one of said optical elements includes a plane mirror.
Claim 24
Independent Claim
96 words
A method of exposing a pattern present on a reticle onto a
photosensitive substrate so as to manufacture a semiconductor device,
comprising the step of : (a) illuminating the reticle with partially polarized light; (b) directing the partially polarized light from the reticle to a
projection optical system comprising a optical element so as to image
the pattern present on the reticle onto the photosensitive substrate;
and (c) forming a substantially unpolarized image of the pattern to be
formed on the photosensitive substrate by using the optical element
providing the partially polarized light for an operation.
Claim 25
Dependent Claim
16 words
A method according to claim 24, wherein the projection optical
system includes a catadioptic optical system.
Claim 26
Dependent Claim
14 words
A method according to claim 24, wherein the optical element
includes a plane mirror.
Claim 27
Dependent Claim
26 words
A method according to claim 24, wherein said illuminating step
includes producing the partially polarized light having first and
second polarization components with different respective intensities.
References Cited (Backward Citations)
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