Stationary and dynamic radial transverse electric polarizer for high numerical aperture systems

• US 7,206,059 B2
• Filed: 02/26/2004
• Issued: 04/17/2007
• Est. Priority Date: 02/27/2003
• Status: Expired due to Fees

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Straaijer, Alexander, Dierichs, Marcel Mathijs Theodore Marie, Flagello, Donis George, Cummings, Kevin
• Primary Examiner(s): FULLER, RODNEY EVAN
• Application Number:
  US10/786,473
• Publication Number:
  US 20040227923A1
• Time in Patent Office: 1,146 Days
• Field of Search: 355/71, 359/350, 359/352, 359/486, 359/495
• US Class Current: 355/71
• CPC Class Codes: G02B 5/3058 comprising electrically conductive elements, e.g. wire grids, conductive particles
• CPC Class Codes: G03F 7/70566 Polarisation control

Abstract

A radial transverse electric polarizer device includes a substrate material having a first refractive index and a plurality of elongated azimuthally oriented elements coupled to the substrate material, the plurality of elongated elements having a second refractive index. The plurality of elements are periodically spaced apart to form a plurality of gaps such that the radial transverse electric polarizer device interacts with an electromagnetic radiation including first and second polarizations to reflect substantially all of the radiation of the first polarization and transmit substantially all of the radiation of the second polarization. The plurality of elongated elements are coated with this thin layer of absorbing material which absorbs radiation at a wavelength of the electromagnetic radiation. The polarizer device may be used, for example, in a lithographic projection apparatus to increase imaging resolution.

Claims

1. A lithographic projection apparatus, comprising:

a radiation system configured to provide a projection beam of radiation;

a support configured to support a patterning device, the patterning device configured to pattern the beam according to a desired pattern;

a substrate table configured to hold a substrate;

a projection system configured to project the patterned beam onto a target portion of the substrate; and

a polarizer device constructed and arranged to polarize said beam of radiation in a transverse electric polarization direction, said polarizer device comprising a plurality of elongated elements and a thin layer of absorbing material, said thin layer of absorbing material absorbing radiation at a wavelength of said beam of radiation,

wherein said plurality of elongated elements are coated with said thin layer of absorbing material.

2. A lithographic projection apparatus according to claim 1,

wherein said polarizer device further comprises:

a first layer of material having a first refractive index;

a second layer of material having a second refractive index; and

said plurality of elongated elements are azimuthally and periodically spaced apart, and disposed between said first layer and said second layer, said plurality of elongated elements interact with said beam of radiation to transmit transverse electric polarization of said beam of radiation.

3. A lithographic projection apparatus according to claim 1,

wherein said polarizer device further comprises:

a substrate material having a first index; and

said plurality of elongated elements are azimuthally oriented and coupled with said substrate material, said elongated elements having a second refractive index, said plurality of elongated elements are periodically spaced apart to form a plurality of gaps such that said polarizer device interacts with the beam of radiation comprising first and second polarizations to reflect substantially all of the radiation of the first polarization and transmit substantially all of the radiation of the second polarization.

4. A lithographic projection apparatus according to claim 3,

wherein said thin layer of absorbing material is selected such that a portion of reflected radiation of the first polarization transformed into a secondary radiation of a second polarization is substantially absorbed by said thin layer of absorbing material.

5. A lithographic projection apparatus according to claim 3,

wherein the radiation of the second polarization is minimally absorbed by said thin layer of absorbing material.

6. A lithographic projection apparatus according to claim 3,

wherein said thin layer of absorbing material substantially eliminates polarization flare in the transmitted radiation of a second polarization.

7. A lithographic projection apparatus according to claim 3,

wherein the second polarization is a transverse electric polarization.

8. A lithographic projection apparatus according to claim 1,

wherein said thin layer of absorbing material is selected from the group:

Al₂O₃ and anodic oxidized aluminum.

9. A lithographic projection apparatus according to claim 1,

wherein a wavelength range of said radiation beam is in the ultraviolet spectrum.

10. A lithographic projection apparatus according to claim 9,

wherein said wavelength range is between 365 nm and 126 nm.

11. A lithographic projection apparatus according to claim 9,

wherein said wavelength range is in the extreme ultraviolet.