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CN-122000776-A - Laser device and method for manufacturing electronic device

CN122000776ACN 122000776 ACN122000776 ACN 122000776ACN-122000776-A

Abstract

The invention provides a laser device and a method for manufacturing an electronic device. The laser device includes an oscillator that emits a pulse laser, a random phase plate that is disposed on an optical path of the pulse laser, and an optical pulse stretcher that is disposed on the optical path of the pulse laser after passing through the random phase plate, and that causes one portion of the pulse laser to pass through and the other portion to circulate in a delay optical path for at least 1 week, thereby outputting a transmitted light and a circulating light, and that expands a pulse time width of the pulse laser.

Inventors

  • FUJIMAKI YOSUKE

Assignees

  • 极光先进雷射株式会社

Dates

Publication Date
20260508
Application Date
20251009
Priority Date
20241105

Claims (15)

  1. 1. A laser device is provided with: an oscillator that emits a pulse laser; a random phase plate arranged on the optical path of the pulse laser, and An optical pulse stretcher, which is disposed on the optical path of the pulse laser after passing through the random phase plate, transmits a part of the pulse laser and circulates another part in a delay optical path for at least 1 week to output transmitted light and circulating light, thereby expanding a pulse time width of the pulse laser.
  2. 2. The laser device according to claim 1, wherein, The light paths of the transmitted light and the surrounding light outputted from the optical pulse stretcher are shifted.
  3. 3. The laser device according to claim 2, wherein, The light paths of the transmitted light and the surrounding light which are staggered are parallel.
  4. 4. The laser device according to claim 2, wherein, The optical pulse stretcher has a plurality of mirrors that constitute the delay optical path, The plurality of mirrors are arranged so that the delay optical path is offset from the optical path at which each of the surrounding lights is emitted when the number of surrounding lights is 2 or more.
  5. 5. The laser device according to claim 2, wherein, The amount of shift of the optical path generated each time the surrounding light surrounds 1 week in the delay optical path is equal to or more than the pixel size of the random phase plate.
  6. 6. The laser device according to claim 5, wherein, The offset is 2 times or less the pixel size.
  7. 7. The laser device according to claim 1, wherein, When the size of the coherent region of the pulse laser beam emitted from the oscillator is a, the pixel size of the random phase plate is 0.5a or more.
  8. 8. The laser device according to claim 1, wherein, The pixel size of the random phase plate is more than 0.05 mm.
  9. 9. The laser device according to claim 1, wherein, The optical pulse stretcher includes a beam splitter and a concave mirror.
  10. 10. The laser device according to claim 9, wherein, The delay light path is composed of a plurality of concave mirrors.
  11. 11. The laser device according to claim 1, wherein, The oscillator includes an excimer laser apparatus.
  12. 12. The laser device according to claim 1, wherein, A second optical pulse stretcher is provided downstream of the first optical pulse stretcher as the optical pulse stretcher.
  13. 13. The laser device according to claim 12, wherein, A third optical pulse stretcher is provided downstream of the second optical pulse stretcher.
  14. 14. The laser device according to claim 1, wherein, The random phase plate is stationary.
  15. 15. A method of manufacturing an electronic device, wherein, The manufacturing method of the electronic device comprises the following steps: The laser light is generated by a laser device, The laser light is output to an exposure device, Exposing the laser light on a photosensitive substrate in the exposure apparatus to manufacture an electronic device, The laser device is provided with: an oscillator that emits a pulse laser; a random phase plate arranged on the optical path of the pulse laser, and An optical pulse stretcher, which is disposed on the optical path of the pulse laser after passing through the random phase plate, transmits a part of the pulse laser and circulates another part in a delay optical path for at least 1 week to output transmitted light and circulating light, thereby expanding a pulse time width of the pulse laser.

Description

Laser device and method for manufacturing electronic device Technical Field The present disclosure relates to a laser device and a method of manufacturing an electronic device. Background In recent years, in semiconductor exposure apparatuses, resolution improvement has been demanded with miniaturization and high integration of semiconductor integrated circuits. Therefore, the wavelength of the light emitted from the exposure light source is being shortened. For example, as a gas laser device for exposure, a KrF excimer laser device that outputs laser light having a wavelength of about 248nm and an ArF excimer laser device that outputs laser light having a wavelength of about 193nm are used. The natural oscillation light of the KrF excimer laser device and the ArF excimer laser device has a wide spectral line width of 350-400 pm. Therefore, when the projection lens is made of a material that transmits ultraviolet rays such as KrF and ArF laser light, chromatic aberration may occur. As a result, the resolution may be lowered. Therefore, it is necessary to narrow the line width of the laser light output from the gas laser device to such an extent that chromatic aberration can be disregarded. Therefore, in a laser resonator of a gas laser device, there is a case where a narrow-band module (Line Narrowing Module:lnm) including narrow-band elements (etalons, gratings, etc.) is provided in order to narrow the line width. Hereinafter, a gas laser device whose line width is narrowed is referred to as a narrowed gas laser device. Prior art literature Patent literature Patent document 1 International publication No. 2018/138819 Disclosure of Invention A laser device according to one aspect of the present disclosure includes an oscillator that emits a pulse laser, a random phase plate that is disposed on an optical path of the pulse laser, and an optical pulse stretcher that is disposed on the optical path of the pulse laser after passing through the random phase plate, and that causes a part of the pulse laser to transmit and another part to surround at least 1 week in a delay optical path, and outputs transmitted light and surrounding light, thereby expanding a pulse time width of the pulse laser. The method for manufacturing an electronic device according to another aspect of the present disclosure includes the steps of generating laser light by a laser device, outputting the laser light to an exposure device, and exposing the laser light to a photosensitive substrate in the exposure device to manufacture the electronic device, wherein the laser device includes an oscillator that emits pulse laser light, a random phase plate that is disposed on an optical path of the pulse laser light, and an optical pulse stretcher that is disposed on the optical path of the pulse laser light after passing through the random phase plate, and that transmits one portion of the pulse laser light and outputs transmitted light and surrounding light by surrounding at least 1 week in a delayed optical path, thereby expanding a pulse time width of the pulse laser light. Drawings Hereinafter, several embodiments of the present disclosure will be described, by way of example only, with reference to the accompanying drawings. Fig. 1 is a view showing an example of a speckle image obtained by capturing a pattern of bright and dark speckles. Fig. 2 is a diagram showing a histogram of the brightness of the speckle image shown in fig. 1. Fig. 3 schematically shows a configuration example of the laser device of the comparative example. Fig. 4 is an explanatory diagram of a method of shifting the angle of the beam according to the number of beam loops in the OPS. Fig. 5 is an explanatory diagram of a method of shifting the positions of beams according to the number of beam loops in the OPS. Fig. 6 schematically shows a configuration example of the laser device of embodiment 1. Fig. 7 is an explanatory diagram schematically showing an operation of shifting the optical path of the surrounding light by a structure in which a random phase plate and OPS are combined. Fig. 8 is a diagram schematically showing an example of a pattern of pixels of a random phase plate. Fig. 9 is a graph showing a change in the electric field of a beam passing through a random phase plate. Fig. 10 is a diagram showing a change in the electric field of a beam passing through the OPS. Fig. 11 is a diagram showing a change in electric field caused by a combination of the random phase plate and OPS in embodiment 1. Fig. 12 is a diagram showing a change in the electric field of the beam when the OPS is arranged in the near front (upstream side) and the random phase plate is arranged in the subsequent stage. Fig. 13 shows a cross section of a beam emitted from the OPS. Fig. 14 is a diagram showing a method of measuring the amount of beam deflection by the OPS. Fig. 15 schematically shows a configuration example of an exposure apparatus. Detailed Description Catalogue- 1. Descrip