US 7,095,560 B2 · Diffractive optical device, refractive optical device, illumination optical system, exposure apparatus and exposure method

Abstract

An illumination optical system having a more simplified structure forms various quadrupole-shaped secondary light sources with two-time rotational symmetry with respect to an optical axis. The apparatus can provide illumination conditions that differ in two perpendicular directions on a radiation-receiving plane. In order to form a secondary light source with a quadrupole-shaped light intensity distribution on an illumination pupil plane, a diffractive optical device is provided in which an entrance light beam is converted into four light beams, and a light beam having a shape of four points centered about the optical axis is formed in a far field. The diffractive optical device is provided with a first diffractive optical member that is rotatable about a first axis parallel to the optical axis, and a second diffractive optical member that is rotatable about a second axis parallel to the optical axis, and that is arranged adjacent to the first diffractive optical member. A refractive optical device having first and second refractive optical members accomplishes similar results.

Claims47

Dependent claims

A diffractive optical device for use in an illumination optical system that illuminates an illuminated surface, and that converts an incident light beam into multiple light beams to form a secondary light source having a multipole light intensity distribution on an illumination pupil plane, the diffractive optical device comprising:

a first diffractive optical member that is rotatable about a first axis that intersects the first diffractive optical member and that is parallel to an optical axis of the illumination optical system;
and
a second diffractive optical member that is rotatable about a second axis that is parallel to the optical axis, and that is displaced from the first axis in an orthogonal plane that is orthogonal to the optical axis so that the second diffractive optical member is adjacent to the first diffractive optical member.

a first diffractive optical member that is rotatable about a predetermined axis that intersects the first diffractive optical member and that is parallel to an optical axis of the illumination optical system;
and
a second diffractive optical member that is rotatable about the predetermined axis;
wherein:
in the first diffractive optical member and the second diffractive optical member, at least a part of annular regions defined by a plurality of concentric circles are formed so as to be substantially the same;
in the first diffractive optical member, diffraction surfaces are formed in odd-numbered regions starting from the center among the annular regions;
and
in the second diffractive optical member, diffraction surfaces are formed in even-numbered regions starting from the center among the annular regions.

5 more elements

Dependencies are inferred from the claim text.

Diffractive optical device, refractive optical device, illumination optical system, exposure apparatus and exposure method

Life of this patent

Diffractive optical device, refractive optical device, illumination optical system, exposure apparatus and exposure method

Life of this patent

Abstract

Claims47