US6633365B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Projection optical system and exposure apparatus having the projection optical system
Assignee: Nikon Corp
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Filing: 2001-12-10
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Granted: 2003-10-14
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Expires: 2021-12-10
Abstract
Abstract A projection optical system according to the present invention whose image side numerical aperture is greater than or equal to 0.75, and which forms an image of a first object upon a second object using light of a predetermined wavelength less than or equal to 300 nm, comprises: a first lens group G 1 of positive refractive power; a second lens group G 2 of negative refractive power; a third lens group G 3 of positive refractive power; and a fourth lens group G 4 of positive refractive power, and: the first lens group G 1, the second lens group G 2, the third lens group G 3 and the fourth lens group G 4 are arranged in order from a side of the first object; and a distance D in mm along an optical axis between an optical surface of the fourth lens group G 4 closest to the second object, and the second object, satisfies a condition of 0.1<D<5.
Inventors
- 👤 Yutaka Suenaga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:37
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70216; G03F7/70241; G02; G02B; G02B13/00; G02B13/14; G02B13/143; G02B27/00; G02B27/18; G03F7/70341
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
158 words
A projection optical system whose image side numerical aperture is greater than or equal to 0.75, and which forms an image of a first object upon a second object using light of a predetermined wavelength less than or equal to 300 nm, comprising: a first lens group G 1 of positive refractive power; a second lens group G 2 of negative refractive power; a third lens group G 3 of positive refractive power; and a fourth lens group G 4 of positive refractive power, wherein: the first lens group G 1 , the second lens group G 2 , the third lens group G 3 and the fourth lens group G 4 are arranged in order from a side of the first object; and a distance D in mm along an optical axis between an optical surface of the fourth lens group G 4 closest to the second object, and the second object, satisfies a condition of 0.1<D<5.
Claim 2
Dependent Claim
158 words
A projection optical system whose image side numerical aperture is greater than or equal to 0.75, and which forms an image of a first object upon a second object using light of a predetermined wavelength less than or equal to 300 nm, comprising: a first lens group G 1 of positive refractive power; a second lens group G 2 of negative refractive power; a third lens group G 3 of positive refractive power; and a fourth lens group G 4 of positive refractive power, wherein: the first lens group G 1 , the second lens group G 2 , the third lens group G 3 and the fourth lens group G 4 are arranged in order from a side of the first object; and a distance D in mm along an optical axis between an optical surface of the fourth lens group G 4 closest to the second object, and the second object, satisfies a condition of 0.1<D<5.
Claim 3
Dependent Claim
26 words
A projection optical system according to claim 1 , wherein the projection optical system has an image side numerical aperture greater than or equal to 0.8.
Claim 4
Dependent Claim
70 words
A projection optical system according to claim 1 , wherein, with T being a sum of thicknesses along the optical axis of all optical members included in the fourth lens group G 4 , and with D being the distance along the optical axis between the optical surface of the fourth lens group G 4 closest to the second object, and the second object, a condition of 0.001<D/T<0.2 is satisfied.
Claim 5
Dependent Claim
59 words
A projection optical system according to claim 1 , wherein, with T being a sum of the thicknesses along the optical axis of all optical members included in the fourth lens group G 4 , and with L being a distance along the optical axis between the first object and the second object, a condition of 0.02<T/L is satisfied.
Claim 6
Dependent Claim
32 words
A projection optical system according to claim 1 , wherein a distance L in mm along the optical axis between the first object and the second object satisfies a condition of 800<L<1600.
Claim 7
Dependent Claim
45 words
A projection optical system according to claim 1 , wherein a focal length F 2 of the second lens group G 2 and a distance L in mm along the optical axis between the first object and the second object satisfy a condition of 0.01<|F2|/L<0.15.
Claim 8
Dependent Claim
31 words
A projection optical system according to claim 1 , wherein at least one of a plurality of optical surfaces comprised in the projection optical system is formed in an aspherical shape.
Claim 9
Dependent Claim
82 words
An exposure apparatus, comprising: an illumination system for illuminating a mask as a first object; a projection optical system according to claim 1 , that forms an image of a pattern which is formed upon the mask upon a photosensitive substrate as the second object; and a prevention device that prevents gas which is generated from the photosensitive substrate from adhering to the optical surface closest to the second object of the fourth lens group G 4 of the projection optical system.
Claim 10
Dependent Claim
50 words
An exposure apparatus according to claim 8 , wherein the prevention device comprises a flow forming device that forms a predetermined flow of gas or liquid in a optical path between the optical surface closest to the second object of the fourth lens group G 4 and the photosensitive substrate.
Claim 11
Dependent Claim
123 words
An exposure method, comprising: an illumination process of illuminating a mask as a first object; and an exposure process of exposing, via a projection optical system according to claim 1 , an image of a pattern which is formed upon the mask upon a photosensitive substrate as the second object, wherein the exposure process comprises a flow formation process of forming a predetermined flow of gas or liquid in a optical path between the optical surface closest to the second object of the fourth lens group G 4 and the photosensitive substrate, in order to prevent gas which is generated from the photosensitive substrate from adhering to the optical surface closest to the second object of the fourth lens group G 4 .
Claim 12
Dependent Claim
47 words
A method for manufacturing a microdevice, comprising: an exposure process of exposing a pattern on a mask upon a photosensitive substrate, using an exposure method according to claim 10 ; and a development process of developing the photosensitive substrate which has been exposed by the exposure process.
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