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KR-102961042-B1 - Transmissive diffuser

KR102961042B1KR 102961042 B1KR102961042 B1KR 102961042B1KR-102961042-B1

Abstract

A diffuser is configured to receive and transmit radiation. The diffuser includes a scattering layer (510) configured to scatter the received radiation, wherein the scattering layer (510) contains a first material and has a plurality of voids distributed therein. The first material may be a scattering material, or alternatively, at least one of the voids contains a scattering material and the first material has a lower refractive index than the scattering material.

Inventors

  • 클루그키스트, 주스트, 안드레
  • 니키펠로브, 안드레이
  • 엔겔렌, 바우터, 윱
  • 리안, 진
  • 베르묄렌, 폴, 알렉산더
  • 예겐, 할릴, 고카이

Assignees

  • 에이에스엠엘 네델란즈 비.브이.

Dates

Publication Date
20260508
Application Date
20200924
Priority Date
20191011

Claims (15)

  1. In a diffuser configured to receive and transmit radiation, The above diffuser includes a scattering layer configured to scatter received radiation, and The scattering layer comprises a first material and has a plurality of voids distributed therein, and The above first substance is a scattering substance, or At least one of the above voids contains a scattering material, and the first material has a lower refractive index than the scattering material, A diffuser that produces a hologram upon acceptance of radiation at the surface of the scattering layer, by the cooperation of the first material and the void.
  2. In claim 1, the first material is a scattering material, the scattering material comprises a foam having pores, the void is provided by the pores, and the void is a diffuser containing a vacuum or an inert gas.
  3. In paragraph 2, the void is a diffuser containing either silicon or silicon nitride.
  4. In claim 1, the void contains the scattering material, the first material comprises a porous silicon-based structure, and the void is a diffuser defined by the pores of the first material.
  5. In claim 1, the scattering material comprises the body of the contact particle, and the void is a diffuser provided between adjacent particles.
  6. In paragraph 5, the above particles comprise a binary mixture comprising a first material and a second material having a refractive index different from that of the first material, in a diffuser.
  7. In claim 6, the first material comprises silicon, and the second material comprises molybdenum or ruthenium.
  8. In claim 1, the diffuser further comprises a support structure, the scattering layer at least partially covers the support structure, and the support structure comprises a nanotube.
  9. delete
  10. A diffuser according to claim 1, wherein the void contains a second material, the real part of the refractive index of the second material is different from the real part of the refractive index of the first material, and the imaginary part of the refractive index of the second material is similar to the imaginary part of the refractive index of the first material.
  11. In claim 1, the first material comprises at least one of the following: molybdenum, ruthenium, niobium, rhodium, yttrium, zirconium, or technetium.
  12. In item 10, the second material is a diffuser containing silicon.
  13. In holographic diffusers, It includes a spawning layer, The scattering layer comprises a plurality of structures configured to generate a hologram upon receiving extreme ultraviolet radiation at the surface of the scattering layer, and The hologram is a holographic diffuser having at least a strong angular intensity profile in the radially outer part of the hologram compared to the central region of the hologram.
  14. In a lithography apparatus, A measurement system for determining an aberration map or a relative intensity map for a projection system comprising a diffuser of any one of claims 1 to 8 and claims 10 to 12; and A lithography device comprising a projection system configured to receive at least a portion of radiation scattered by a patterning device and configured to project the received radiation onto a sensor device.
  15. In a method for forming a diffuser for receiving and transmitting radiation, It includes creating a plurality of structures on the surface of the support layer of the above-mentioned diffuser, and A method in which the above structures are arranged to generate a hologram upon receiving radiation at a surface.

Description

Transmissive diffuser Cross-reference regarding related applications This application claims priority to EP application 19202644.1 filed on October 11, 2019, the contents of which are incorporated herein by reference in their entirety. The present invention relates to a transmissive diffuser, that is, a diffuser configured to receive and transmit radiation, wherein the transmitted radiation has a modified angular distribution. The diffuser may be suitable for use with EUV radiation and may form part of a measurement system within an EUV lithography apparatus. A lithography device is a machine configured to apply a desired pattern onto a substrate. A lithography device can be used, for example, in the manufacture of an integrated circuit (IC). A lithography device can project a pattern on a patterning device (e.g., a mask) onto a layer of a radiation-sensitive material (resist) provided on a substrate. To project a pattern onto a substrate, a lithography device may use electromagnetic radiation. The wavelength of this radiation determines the minimum size of features that can be formed on the substrate. A lithography device using extreme ultraviolet (EUV) radiation with a wavelength in the range of 4 to 20 nm, for example, 6.7 nm or 13.5 nm, is used to form features on the substrate that are smaller than those formed by a lithography device using radiation with a wavelength of, for example, 193 nm. A lithography device is known to include a measurement system for determining one or more pupil function variations. Pupil function variations may include relative phase variations within the pupil plane and/or relative intensity variations within the pupil plane. Such a measurement system typically includes an object-level patterning device (e.g., a diffraction grating or a pinhole, etc.); an illumination system; and an image-level sensor device. The illumination system is arranged to illuminate the patterning device with radiation. At least a portion of the radiation scattered by the patterning device is received by a projection system (whose characteristics are being measured) positioned to form an image of the patterning device on the image-level sensor device. For such a measurement system, it is desirable that the entire incident pupil of the projection system receives radiation from the patterning device. However, the illumination system is also typically used by a lithography device to form an (diffraction-limited) image of an object-level reticle or mask on an image-level substrate (e.g., a resist-coated silicon wafer), where it may be desirable to illuminate only one or more individual parts of the incident pupil of the projection system. It may be desirable to provide a mechanism that allows the entire incident pupil of the projection system to receive radiation from the patterning device, thereby changing the angular distribution of the illumination beam that would otherwise illuminate one or more individual parts of the incident pupil of the projection system. Embodiments of the present invention will be described merely as examples with reference to the attached schematic drawings, and in the drawings: Figure 1 illustrates a lithography system including a lithography device and a radiation source. Figure 2 is a schematic diagram of a reflective marker. Figures 3a and 3b are schematic diagrams of a sensor device. Figure 4a shows the intensity distribution for the dipole illumination mode of the lithography device shown in Figure 1. Figure 4b shows the intensity distribution for the quadrupole illumination mode of the lithography device shown in Figure 1. FIGS. 5a to 5c schematically illustrate intermediate stages in an exemplary process for manufacturing a transmissive diffuser. FIGS. 6a to 6c schematically illustrate intermediate stages in another exemplary process for manufacturing a transmissive diffuser. FIGS. 7a through 7e schematically illustrate intermediate stages in another exemplary process for manufacturing a transmissive diffuser. FIGS. 8a through 7d schematically illustrate intermediate stages in another exemplary process for manufacturing a transmissive diffuser. FIGS. 9a through 9e schematically illustrate intermediate stages in another exemplary process for manufacturing a transmissive diffuser. FIGS. 10a to 10e schematically illustrate intermediate stages in another exemplary process for manufacturing a transmissive diffuser. FIGS. 11a to 11c schematically illustrate intermediate stages in another exemplary process for manufacturing a transmissive diffuser. Figure 12 schematically illustrates an EUV diffuser. Figure 13 shows a plot of the absorption coefficient (k) of EUV radiation against the magnitude of (1-n) for some materials. FIGS. 14a to 14c schematically illustrate intermediate stages in another exemplary process for manufacturing a transmissive diffuser. FIG. 15a shows a height map of an exemplary diffuser manufactured according to the process of FIG. 14a to FIG. 14c. Figures