Nikon Corporation

Hitoshi Matsuzawa

Yutaka Suenaga

Kazumasa Endo

Issey Tanaka

Mikihiko Ishii

Misako Kobayashi

Koji Shigematsu

A projection optical system of the present invention has a first lens group G being positive, a second lens group G being negative, a third lens group G being positive, a fourth lens group G being negative, a fifth lens group G being positive, and a sixth lens group G being positive in the named order from the first object toward the second object, in which the second lens group G comprises an intermediate lens group G between a negative front lens L and a negative rear lens L and in which the intermediate lens group G is arranged to comprise at least a first positive lens being positive, a second lens being negative, a third lens being negative, and a fourth lens being negative in the named order from the first object toward the second object. The present invention involves findings of suitable focal length ranges for the first to the sixth lens groups G to G and an optimum range of an overall focal length of from the second negative lens to the fourth lens with respect to a focal length of the second lens group G .

Exposure apparatus

A projection optical system of the present invention has a first lens group G.sub.1 being positive, a second lens group G.sub.2 being negative, a third lens group G.sub.3 being positive, a fourth lens group G.sub.4 being negative, a fifth lens group G.sub.5 being positive, and a sixth lens group G.sub.6 being positive in the named order from the first object toward the second object, in which the second lens group G.sub.2 comprises an intermediate lens group G.sub.2M between a negative front lens L.sub.2F and a negative rear lens L.sub.2R and in which the intermediate lens group G.sub.2M is arranged to comprise at least a first positive lens being positive, a second lens being negative, a third lens being negative, and a fourth lens being negative in the named order from the first object toward the second object. The present invention involves findings of suitable focal length ranges for the first to the sixth lens groups G.sub.1 to G.sub.6 and an optimum range of an overall focal length of from the second negative lens to the fourth lens with respect to a focal length of the second lens group G.sub.2.

The present invention relates to an exposure apparatus having a high-performance projection optical system having a relatively large numerical aperture and achieving bitelecentricity and superior correction of aberrations, particularly distortion, in a very wide exposure area. Particularly, the protection optical system according to the present invention is composed of a first lens group G.sub.1 with a positive refracting power, a second lens group G.sub.2 with a negative refracting power, a third lens group G.sub.3 with a positive refracting power, a fourth lens group G.sub.4 with a negative refracting power, and a fifth lens group G.sub.5 with a positive refracting power in order from the side of a first object R. The present invention is directed to finding of suitable ranges of focal lengths for the first to fifth lens groups G.sub.1 -G.sub.5, based on the above arrangement.

The present invention relates to an exposure apparatus using a projection optical system to realize a small size and the bitelecentricity as securing a wide exposure area and a large numerical aperture and to realize extremely good correction for aberrations, particularly for distortion. The projection optical system comprises a first lens group G.sub.1 with a positive refracting power, a second lens group G.sub.2 with a negative refracting power, a third lens group G.sub.3 with a positive refracting power, a fourth lens group G.sub.4 with a negative refracting power, a fifth lens group G.sub.5 with a positive refracting power, and a sixth lens group G.sub.6 with a positive refracting power in order from the side of the first object R, wherein the second lens group G.sub.2 comprises a front lens L.sub.2F with a negative refracting power, a rear lens L.sub.2R of a negative meniscus shape, and an intermediate lens group G.sub.2M disposed between the front lens and the rear lens, and wherein the intermediate lens group G.sub.2M has a first lens L.sub.M1 with a positive refracting power, a second lens L.sub.M2 with a negative refracting power, and a third lens L.sub.M3 with a negative refracting power in order from the side of the first object R. The system is arranged to satisfy within suitable ranges of focal lengths for the first to sixth lens groups G.sub.1 -G.sub.6, based on the above arrangement.

Projection optical system and exposure apparatus using the same

This invention is directed to a bitelecentric projection optical system very well corrected for various distortions, particularly for distortion (including higher-order distortions) as securing a relatively wide exposure area and a large numerical aperture. The projection optical system according to this invention comprises in order from the object side toward the image side a first lens group having a positive refractive power, a second lens group having a negative refractive power and not including a positive lens, a third lens group having a positive refractive power, a fourth lens group having a negative refractive power, a fifth lens group having a positive refractive power, and a sixth lens group having a positive refractive power. Particularly, the second lens group comprises a front lens disposed nearest to the object, a rear lens disposed nearest to the image, and an intermediate lens group disposed between the front lens and the rear lens and having at least two negative lenses, and the fifth lens group has at least seven positive lenses.

Projection optical system and exposure apparatus provided therewith

The present invention relates to a both-side telecentric projection optical system and an exposure apparatus equipped with this projection optical system. In particular, the projection optical system has a structure for quite favorably correcting various kinds of aberration such as distortion in particular, while securing a relatively broad exposure area and a large numerical aperture.

Growing community of inventors

Setagaya-ku, Japan

Hitoshi Matsuzawa