Projection optical system and exposure apparatus provided therewith

Claim 2

The projection optical system according to Claim 1, wherein said fifth lens group comprises a negative meniscus lens and a first positive lens disposed adjacent to a concave surface of said negative meniscus lens and having a convex surface opposed to the concave surface of said negative meniscus lens.

Claim 3

The projection optical system according to Claim 1, wherein said fifth lens group comprises a first positive meniscus lens disposed nearest to said first object and having a convex surface directed to said second object, a second positive meniscus lens disposed on the side of said second object with respect to said first positive meniscus lens and having a convex surface directed to said second object, and an aperture stop disposed between said first positive meniscus lens and said second positive meniscus lens.

Claim 4

A projection optical system for projecting an image of a first object onto a second object, comprising: a first lens group disposed between said first object and said second object and having a positive refractive power; a second lens group disposed between said first lens group and said second object and not including a positive lens, wherein said second lens group comprises, a front lens disposed nearest to said first object, having a concave surface directed to said second object, and having a negative refractive power, a rear lens disposed nearest to said second object, having a concave surface directed to said first object, and having a negative refractive power, and an intermediate lens group disposed between said front lens in the second lens group and said rear lens in the second lens group and having at least two negative lenses; a third lens group disposed between said second lens group and said second object and having a positive refractive power; a fourth lens group disposed between said third lens group and said second object and having a negative refractive power; a fifth lens group disposed between said fourth lens group and said second object and having a positive refractive power, wherein said fifth lens group comprises at least seven positive lenses; and a sixth lens group disposed between said fifth lens group and said second object and having a positive refractive power, said projection optical system satisfying the following conditions: 0.1 < f 1 /f 3 < 17 0.05 < f 2 /f 4 < 7 0.01 < f 5 /L < 0.9 0.02 < f 6 /L < 1.6 1.1 < f 2m /f 2 < 9 where f 1 is a focal length of said first lens group, f 2 a focal length of said second lens group, f 3 a focal length of said third lens group, f 4 a focal length of said fourth lens group, f 5 a focal length of said fifth lens group, f 6 a focal length of said sixth lens group, f 2m a composite focal length of the intermediate lens group in said second lens group, and L a distance from said first object to said second object.

Claim 5

The projection optical system according to Claim 4, which satisfies the following condition: 1.0 < I/L where I is an axial distance from said first object to a first object side focal point of the whole of said projection optical system and L the distance from said first object to said second object.

Claim 6

The projection optical system according to Claim 4, wherein said fifth lens group comprises a negative meniscus lens and a first positive lens disposed adjacent to a concave surface of said negative meniscus lens and having a convex surface opposed to the concave surface of said negative meniscus lens, and wherein said fifth lens group satisfies the following condition: 0 < (r 5p - r 5n )/(r 5p + r 5n ) < 1 where r 5n is a radius of curvature of said concave surface of said negative meniscus lens in said fifth lens group and r 5p a radius of curvature of said convex surface opposed to the concave surface of said negative meniscus lens, in said first projection lens in said fifth lens group.

Claim 7

The projection optical system according to Claim 2 or 6, wherein said fifth lens group comprises at least one second positive lens on the side of a convex surface of said negative meniscus lens, and wherein said fifth lens group comprises at least one third positive lens on the opposite side to said negative meniscus lens with respect to said first positive lens disposed adjacent to the concave surface of said negative meniscus lens.

Claim 8

The projection optical system according to Claim 4, wherein said sixth lens group satisfies the following condition: 0.50 < d 6 /r 6F < 1.50 where r 6F is a radius of curvature of a lens surface nearest to the first object in said sixth lens group and d 6 an axial distance from the lens surface nearest to the first object in said sixth lens group to the second object.

Claim 9

The projection optical system according to Claim 1 or 4, wherein said fifth lens group comprises a negative lens disposed nearest to said second object and having a concave surface directed to said second object.

Claim 10

The projection optical system according to Claim 9, wherein said fifth lens group satisfies the following condition: 0.30 < (r 5F - r 5R )/(r 5F + r 5R ) < 1.28 where r 5F is a radius of curvature of a first-object-side lens surface of said negative lens disposed nearest to said second object in said fifth lens group and r 5R a radius of curvature of the second-object-side lens surface of said negative lens disposed nearest to said second object in said fifth lens group.

Claim 11

The projection optical system according to Claim 4, wherein said fifth lens group comprises a first positive meniscus lens disposed nearest to said first object and having a convex surface directed to said second object and a second positive meniscus lens disposed on the side of said second object with respect to said positive meniscus lens and having a convex surface directed to said second object, and wherein said fifth lens group satisfies the following condition: 1.2 < Q 52 /Q 51 < 8 where Q 51 = (r 51F - r 51R )/(r 51F + r 51R ) Q 52 = (r 52F - r 52R )/(r 52F + r 52R ) where r 51F is a radius of curvature of a first-object-side lens surface of said first positive meniscus lens, r 51R a radius of curvature of the second-object-side lens surface of said first positive meniscus lens, r 52F a radius of curvature of a first-object-side lens surface of said second positive meniscus lens, and r 52R a radius of curvature of the second-object-side lens surface of said second positive meniscus lens.

Claim 12

The projection optical system according to Claim 11, wherein said fifth lens group satisfies the following condition: 0.01 < Q 51 < 0.8 where Q 51 = (r 51F - r 51R )/(r 51F + r 51R ) where r 51F is the radius of curvature of the first-object-side lens surface of said first positive meniscus lens in said fifth lens group and r 51R the radius of curvature of the second-object-side lens surface of said first positive meniscus lens in said fifth lens group.

Claim 13

The projection optical system according to Claim 11, further comprising an aperture stop disposed between said first positive meniscus lens and said second positive meniscus lens.

Claim 14

The projection optical system according to Claim 4, wherein said second lens group satisfies the following condition: 0 ≤ f 2F /f 2R < 18 where f 2F is a focal length of said front lens in said second lens group and f 2R a focal length of said rear lens in said second lens group.

Claim 15

The projection optical system according to Claim 1 or 4, wherein said first lens group comprises at least two positive lenses, said third lens group comprises at least three positive lenses, said fourth lens group comprises at least three negative lenses, said fifth lens group comprises at least seven positive lenses and at least one negative lens, and said sixth lens group comprises at least one positive lens.

Claim 16

The projection optical system according to Claim 4, wherein said sixth lens comprises three or less lenses and each lens has at least one lens surface satisfying the following condition: 1/|φL| < 20 where   φ: a refractive power of said lens surface L: the distance from said first object to said second object.

Claim 17

The projection optical system according to Claim 4, wherein a magnification of said projection optical system is 1/4.

Claim 18

An exposure apparatus comprising: a first stage capable of holding a photosensitive substrate on a main surface thereof; an illumination optical system for emitting exposure light of a predetermined wavelength to transfer a predetermined pattern on a mask onto said substrate; a second stage for holding said mask; and a projection optical system disposed between said first stage and said second stage, for projecting an image of said mask onto said substrate, wherein said projection optical system comprises: a first lens group disposed between said first stage and said second stage and having a positive refractive power; a second lens group disposed between said first lens group and said first stage and not including a positive lens, wherein said second lens group comprises, a front lens disposed nearest to said second stage, having a concave surface directed to said first stage, and having a negative refractive power, a rear lens disposed nearest to said first stage, having a concave surface directed to said second stage, and having a negative refractive power, and an intermediate lens group disposed between said front lens in the second lens group and said rear lens in the second lens group and having at least two negative lenses; a third lens group disposed between said second lens group and said first stage and having a positive refractive power; a fourth lens group disposed between said third lens group and said first stage and having a negative refractive power; a fifth lens group disposed between said fourth lens group and said first stage and having a positive refractive power, wherein said fifth lens group comprises at least seven positive lenses; and a sixth lens group disposed between said fifth lens group and said first stage and having a positive refractive power.

Claim 19

The exposure apparatus according to Claim 18, wherein said projection optical system satisfies the following conditions: 0.1 < f 1 /f 3 < 17 0.05 < f 2 /f 4 < 7 0.01 < f 5 /L < 0.9 0.02 < f 6 /L < 1.6 1.1 < f 2m /f 2 < 9 where f 1 is a focal length of said first lens group, f 2 a focal length of said second lens group, f 3 a focal length of said third lens group, f 4 a focal length of said fourth lens group, f 5 a focal length of said fifth lens group, f 6 a focal length of said sixth lens group, f 2m a composite focal length of the intermediate lens group in said second lens group, and L a distance from an object plane on said mask to an image plane on said substrate.