Polarization-modulating element, illumination optical apparatus, exposure apparatus, and exposure method

• US 9,140,990 B2
• Filed: 07/11/2011
• Issued: 09/22/2015
• Est. Priority Date: 02/06/2004
• Status: Active Grant

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Tanitsu, Osamu, Shigematsu, Koji, Hirota, Hiroyuki, Matsuyama, Tomoyuki
• Primary Examiner(s): Chowdhury, Tarifur
• Assistant Examiner(s): Amara, Mohamed
• Application Number:
  US13/067,958
• Publication Number:
  US 20110273697A1
• Time in Patent Office: 1,534 Days
• Field of Search: 356364-370, 356/246, 356/238, 356/290, 362/19
• US Class Current: 1/1
• CPC Class Codes: F21V 13/02 Combinations of only two kinds of elements
• CPC Class Codes: F21V 9/14 for producing polarised light
• CPC Class Codes: G02B 27/0977 Reflective elements
• CPC Class Codes: G02B 27/286 for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34
• CPC Class Codes: G02B 5/3025 Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state G02B5/3008, G02B5/3016 take precedence
• CPC Class Codes: G03F 7/701 Off-axis setting using an aperture
• CPC Class Codes: G03F 7/70191 Optical correction elements, filters or phase plates for controlling intensity, wavelength, polarisation, phase or the like
• CPC Class Codes: G03F 7/70308 Optical correction elements, filters or phase plates for manipulating imaging light, e.g. intensity, wavelength, polarisation, phase or image shift
• CPC Class Codes: G03F 7/70566 Polarisation control

Abstract

There is disclosed a polarization-modulating element for modulating a polarization state of incident light into a predetermined polarization state, the polarization-modulating element being made of an optical material with optical activity and having a circumferentially varying thickness profile.

Claims

1. An illumination optical apparatus for illuminating a surface to be illuminated, based on illumination radiation supplied from a radiation source, comprising:

an optical integrator arranged in an optical path of the illumination radiation;

a polarization modulating element, which is arranged in the optical path of the illumination radiation, is made of an optical material with optical activity, and has a circumferentially varying thickness; and

an annular ratio changing optical system, arranged in an optical path between the polarization modulating element and the surface to be illuminated, that changes an annular ratio of a secondary radiation source formed on a pupil of the illumination optical apparatus,

wherein the illumination optical apparatus satisfies the following conditions;

(10in+Δ

A)/10out<

0.75;

0.4<

(10in+Δ

A)/10out,

where 10in is an effective radius of a central region of the polarization-modulating element,

10out is an outside effective radius of the polarization-modulating element, and

Δ

A is an increase of an inside radius of a beam passing through the annular ratio changing optical system.

2. The illumination optical apparatus according to claim 1, wherein the annular ratio changing optical system comprises an axicon system.

3. The illumination optical apparatus according to claim 2, further comprising an illumination sigma-value changing optical system.

4. An exposure apparatus comprising the illumination optical apparatus according to claim 1, wherein a predetermined pattern is projected onto a photosensitive substrate through the illumination optical apparatus.

5. A device manufacturing method comprising:

projecting a predetermined pattern onto a photosensitive substrate, using the illumination optical apparatus according to claim 1, and

developing the photosensitive substrate.

6. The illumination optical apparatus according to claim 1, wherein the polarization modulating element has a central region with no substantial optical activity.

7. The illumination optical apparatus according to claim 6, further comprising a depolarizer arranged in the optical path in the central region.

8. The illumination optical apparatus according to claim 1, wherein the polarization modulating element is selectively positioned in the optical path of the illumination radiation or out of the optical path of the illumination radiation.

9. The illumination optical apparatus according to claim 8, wherein the polarization modulating element is changeable to another polarization modulating element.