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JP-2026514357-A - Laser chamber playonizer with acoustic scattering surface

JP2026514357AJP 2026514357 AJP2026514357 AJP 2026514357AJP-2026514357-A

Abstract

The apparatus generates laser radiation from a discharge in a discharge chamber, wherein the discharge generates sound waves that, when reflected back to the source, will interfere with the operation of the apparatus at a specific repetition rate, and the surface of a pre-onizer tube positioned within the discharge chamber is provided with acoustic scattering features that scatter sound waves that collide with the surface of the pre-onizer tube. The pre-onizer tube may also be configured to have a cross-section that exhibits a surface at an angle to the region where the discharge is generated. [Selection Diagram] Figure 10

Inventors

  • スタイガー，トーマス，ディクソン

Assignees

  • サイマー リミテッド ライアビリティ カンパニー

Dates

Publication Date
20260511
Application Date
20240321
Priority Date
20230329

Claims (20)

  1. A play-onizer for laser systems, A tube having an outer surface and a tube wall, configured as a substantially cylindrical hollow tube extending axially in a first direction, wherein at least a portion of the outer surface is provided with a plurality of acoustic scattering feature portions, An electrode positioned at least partially within the tube, A playonizer equipped with this feature.
  2. The tube comprises a dielectric material, as described in claim 1.
  3. The playonizer according to claim 1, wherein the acoustic scattering feature portion has a penetration depth into the tube wall that is greater than half the nominal thickness of the tube wall.
  4. The playonizer according to claim 1, wherein the laser system operates at 6 kHz, and the acoustic scattering feature portion has a penetration depth of at least 0.063 inches into the tube wall.
  5. The laser system is configured to generate a discharge in a discharge region having a height H and a width W, and the penetration depth of the acoustic scattering feature portion into the tube wall is in the range of 1/4H to 1/4W, including both ends, as described in claim 1.
  6. The laser system is configured to generate a discharge in the discharge region, and the acoustic scattering feature portion is provided on at least a portion of the outer surface facing the discharge area, as described in claim 1.
  7. The sound scattering feature portion is provided on substantially the entire outer surface, as described in claim 1 of the playonizer.
  8. The playonizer according to claim 1, wherein the acoustic scattering feature portion is manufactured by molding the acoustic scattering feature portion onto at least a portion of the outer surface.
  9. The playonizer according to claim 1, wherein the plurality of acoustic scattering feature portions are arranged in an array provided on at least a portion of the outer surface.
  10. The playonizer according to claim 9, wherein the array is aperiodic.
  11. The playonizer according to claim 1, wherein the closest of the plurality of acoustic scattering feature areas is spaced at a distance of 0.01 inches to 0.5 inches between its edges.
  12. The playonizer according to claim 1, wherein the acoustic scattering feature portions are arranged to have a density ranging from 3 acoustic scattering feature portions per square inch to 100 acoustic scattering feature portions per square inch.
  13. The playonizer according to claim 1, wherein the plurality of acoustic scattering feature portions each have an area ranging from 0.1 square inches to 0.5 square inches.
  14. The playonizer according to claim 1, wherein the plurality of acoustic scattering feature portions have a total coverage of the outer surface in the range of 10 percent to 100 percent.
  15. A playonizer for excimer lasers, A pipe body having a pipe wall, the pipe wall having an external surface, A plurality of baffles provided on the acoustic scattering surface of the outer surface, wherein the acoustic scattering surface extends in the longitudinal direction along the length of the pipe body, and each of the baffles is arranged and sized to scatter acoustic reflections from the acoustic scattering surface, An electrode positioned at least partially within the tube body, A playonizer equipped with this feature.
  16. The tube wall comprises a dielectric material, as described in claim 15.
  17. The pre-ionizer according to claim 15, wherein the baffle has a penetration depth into the tube wall that is greater than half the thickness of the tube wall.
  18. The playonizer according to claim 15, wherein the excimer laser operates at 6 kHz, and the baffle has a penetration depth of at least 0.063 inches into the tube wall.
  19. The excimer laser is configured to generate a discharge in a discharge region having a height H and a width W, and the penetration depth of the baffle into the tube wall is in the range of 1/4H to 1/4L, including both ends, as described in claim 15.
  20. The excimer laser is configured to generate a discharge in the discharge region, and the acoustic scattering surface comprises a portion of the external surface facing the discharge area, as described in claim 15.

Description

(Cross-reference of related applications) [0001] This application claims priority to U.S. Application No. 63/455,476, filed on 29 March 2023, and U.S. Application No. 63/560,973, filed on 4 March 2024, also titled "LASER CHAMBER PREIONIZER HAVING ACOUSTIC SCATTERING SURFACE," which are incorporated herein by reference in their entirety. [0002] The subject matter disclosed relates to a laser discharge chamber in which a discharge in the discharge region generates laser radiation and also generates acoustic disturbances that can be undesirably reflected back into the discharge region. [0003] Photolithography is a process for patterning semiconductor circuits onto substrates such as silicon wafers. A photolithography radiation source provides deep ultraviolet (DUV) radiation (wavelengths ranging from approximately 100 nanometers (nm) to approximately 400 nm) used to expose the photoresist on the wafer. The radiation source is a laser source, and the radiation is often a pulsed laser beam. The radiation beam passes through a beam delivery unit, then through a reticle or mask, and is then projected onto a silicon wafer coated with photoresist. In this way, the chip design is patterned onto the photoresist, and then the photoresist is etched and cleaned. [0004] Many systems that generate a laser beam (e.g., a laser generator) or use a laser beam (e.g., a photolithography system) have an optical train, which includes one or more optical components (e.g., mirrors, gratings, prisms, optical switches, filters). The optical components of the optical train reflect, process, filter, modify, focus, and magnify the laser beam, either entirely or partially, to obtain one or more desired laser beam outputs. [0005] In such systems, the laser beam is generated by inducing a discharge in the inter-electrode discharge region of one or more laser discharge chambers. One challenge in the design and use of these systems is that the discharge that generates the laser radiation also generates strong sound waves within the discharge region. These sound waves create gas density modulation propagating within the laser discharge chamber. Surfaces within the laser discharge chamber can reflect these sound waves back into the discharge region, potentially adversely affecting the laser's performance. Specifically, these reflected waves can lead to round-trip time-of-flight resonance depending on the pulse delay or discharge repetition rate in which the laser system operates. [0006] It would be advantageous to mitigate the adverse effects of these acoustic disturbances. It is in this context that the subject matter of this disclosure arises. [0007] The following provides a brief overview of one or more embodiments to facilitate a basic understanding of the subject matter of this disclosure. This overview is not intended to be a comprehensive overview of all possible embodiments, nor to identify any element of any embodiment as key or significant, nor to describe in detail the scope of any or all embodiments. Its sole purpose is to provide a streamlined presentation of some concepts relating to one or more embodiments as a prelude to the more detailed descriptions that will follow. [0008] According to one aspect of one embodiment, a pre-onizer for a laser system is disclosed, comprising a tube having an outer surface and a tube wall, configured as a substantially cylindrical hollow tube extending axially in a first direction, wherein at least a portion of the outer surface is provided with a plurality of acoustic scattering feature portions, and an electrode positioned at least partially within the tube. [0009] The tube may be made of a dielectric material. The acoustic scattering feature portion may have a penetration depth into the tube wall greater than half the nominal thickness of the tube wall. [0010] When the laser system operates at 6 kHz, the acoustic scattering feature may have a penetration depth of at least 0.063 inches into the tube wall. [0011] The laser system may be configured to generate a discharge in a discharge region having a height H and a width W, and the penetration depth of the acoustic scattering feature portion into the tube wall may be in the range of 1/4H to 1/4W, including both endpoints. [0012] The laser system may be configured to generate a discharge in the discharge region, and the acoustic scattering feature may be provided on at least a portion of the outer surface facing the discharge area. The acoustic scattering feature may be provided on substantially the entire outer surface. [0013] The acoustic scattering feature portion can be fabricated by forming the acoustic scattering feature portion on at least a portion of the outer surface. [0014] The multiple acoustic scattering feature portions may be arranged in an array provided on at least a portion of the outer surface. The array may be non-periodic. [0015] The closest of the multiple acoustic scattering features may be spaced apart by a distance of 0.0