Patent EP0816892A2 successfully refreshed from Google Patents.
EP0816892A2
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Catadioptric lens system
Assignee: Nikon Corp
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Filing: 1997-06-16
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Granted: —
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Expires: 2017-06-16
Abstract
Abstract A catadioptric lens system whose entire size is practically compact and is capable of providing a large numerical aperture in the ultraviolet band region is disclosed. The invention also provides photolithographic resolution of quarter micron levels and is easy to manufacture. The invention comprises, a first lens system S1 constructed with refractive members, a concave mirror M1, and a second lens system S2 constructed with refractive members to project a semiconductor device pattern from a reticle surface onto a substrate wherein at least said first lens system includes one or more aspherical surface(s) which point to the reticle surface.
Inventors
- 👤 Yasuhiro c/o Nikon Corp.(I.P.H.) Fuji Bldg Omura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 15:49
CPC Classifications
G; G02; G02B; G02B17/00; G02B17/08; G02B17/0892; G03; G03F; G03F7/00; G03F7/20; G03F7/2002; G03F7/70; G03F7/70216; G03F7/70225; G03F7/7025
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
68 words
A catadioptric lens system characterized by the fact that said
catadioptric lens system comprises: a) a first lens system constructed with refractive members, b) a concave mirror, and c) a second lens system including refractive members to project a
semiconductor device pattern from a reticle surface onto a substrate wherein
at least said first lens system includes one or more aspherical surface(s) which
point to the reticle surface.
Claim 2
Dependent Claim
95 words
The catadioptric lens system of claim 1, wherein said first lens
system comprises: a) a first lens group having a plurality of lenses in which light enters only
once; and b) a second lens group having a plurality of lenses through which the
light exiting from said first lens group makes a round trip with the second lens
group including a negative lens located at a position closest to the concave
mirror such that the light coming through said second lens group images said
semiconductor device pattern once before entering said second imaging lens
system.
Claim 3
Dependent Claim
31 words
The catadioptric lens system of claim 1, wherein an optical path
reflection member is arranged between said first lens system and said second
lens system or in said second lens system.
Claim 4
Dependent Claim
17 words
The catadioptric lens system of claim 3 wherein said optical path
reflection member is a plane mirror.
Claim 5
Dependent Claim
39 words
The catadioptric lens system of claim 1, wherein said refractive
members in said first lens system and said refractive members in said second
lens system are constructed from a mineral selected from the group consisting
of quartz and fluorite.
Claim 6
Dependent Claim
14 words
The catadioptric lens system of claim 1, wherein said concave mirror
is aspherically shaped.
Claim 7
Dependent Claim
25 words
The catadioptric lens system of claim 2, wherein an optical path
reflection member is arranged between said first lens system and said second
lens system.
Claim 8
Dependent Claim
38 words
The catadioptric lens system of claim 2, wherein said refractive
members in said first lens system and said refractive members in said second
lens systemare constructed from a mineral selected from the group consisting
of quartz and fluorite.
Claim 9
Dependent Claim
39 words
The catadioptric lens system of claim 3, wherein said refractive
members in said first lens system and said refractive members in said second
lens system are constructed from a mineral selected from the group consisting
of quartz and fluorite.
Claim 10
Dependent Claim
14 words
The catadioptric lens system of claim 2, wherein said concave
mirror is aspherically shaped.
Claim 11
Dependent Claim
14 words
The catadioptric lens system of claim 3, wherein said concave
mirror is aspherically shaped.
Claim 12
Dependent Claim
14 words
The catadioptric lens system of claim 5, wherein said concave
mirror is aspherically shaped.
Claim 13
Dependent Claim
41 words
The catadioptric lens system of claim 10 wherein at least one of the
refractive members in the first lens system has at least two different negative
refractive powers and wherein another refractive member has at least two
different positive refractive powers.
References Cited (Backward Citations)
No citation records indexed.
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