Projection optical unit and projection exposure apparatus comprising the same

A projection exposure apparatus for exposing a photosensitive substrate by projection with a pattern on a mask, comprising:

• an illuminating unit that illuminates the mask;
• and
• a projection optical unit that forms an image of the mask pattern on the photosensitive substrate;
• said projection optical unit comprising:
• a barrel;
• a plurality of optical elements held coaxially in the barrel;
• at least two optical elements of the plurality of optical elements being optical elements which produce asymmetric component aberration relative to an optical axis of the optical elements;
• and
• a rotating mechanism that relatively rotates the at least two optical elements about the optical axis respectively;
• and
• said rotating mechanism comprising inner optical element frames, which are rotatable in the barrel about the optical axis as a center, that hold the at least two optical elements respectively, and outer optical element frames, which are arranged between the inner optical element frames and the barrel, that rotatably support the inner optical element frames.

A projection optical unit for projecting an image of a first object onto a second object, comprising:

• a barrel;
• a plurality of optical elements held coaxially in the barrel;
• at least two optical elements of the plurality of optical elements being lenses each having different radii of curvature;
• a rotating mechanism that relatively rotates the at least two optical elements about an optical axis of the optical elements respectively;
• said rotating mechanism comprising optical element frames, each of which is rotatable in the barrel about the optical axis, that hold the at least two optical elements respectively.

A projection exposure apparatus for projecting a mask pattern onto a substrate through a projection optical system;

• a barrel of the projection optical system;
• a plurality of optical elements held coaxially in the barrel;
• at least two optical elements of the plurality of optical elements being lenses each having different radii of curvature;
• a rotating mechanism that relatively rotates the at least two optical elements about an optical axis of the optical elements;
• said rotating mechanism comprising optical element frames, each of which is rotatable in the barrel about the optical axis, that hold the at least two optical elements respectively,
• wherein asymmetric aberration of the projection optical system is corrected by relatively rotating the at least two optical elements by virtue of the rotating mechanism.

A method for manufacturing an exposure apparatus having a projection optical system, the projection optical system having an optical axis, the method comprising the steps of:

• providing a barrel having at least first and second lenses therein, the first and second lenses each having radii of curvature rotationally asymmetrically different relative to the optical axis;
• providing a first frame that holds the first lens;
• and
• providing a second frame that holds the second lens.