Laser radiation system and method for manufacturing electronic device

Patent metadata

Field	Value
Publication number	US-11768362-B2
Application number	US-202016853611-A
Country	US
Kind code	B2
Filing date	Apr 20, 2020
Priority date	Dec 7, 2017
Publication date	Sep 26, 2023
Grant date	Sep 26, 2023

Abstract

A laser radiation system according to a viewpoint of the present disclosure includes a first optical system configured to convert a first laser flux into a second laser flux, a multimirror device including mirrors, configured to be capable of controlling the angle of the attitude of each of the mirrors, and configured to divide the second laser flux into laser fluxes and reflect the laser fluxes in directions to produce the divided laser fluxes, a Fourier transform optical system configured to focus the divided laser fluxes, and a control section configured to control the angle of the attitude of each of the mirrors in such a way that the Fourier transform optical system superimposes the laser fluxes, which are divided by the mirrors separate from each other by at least a spatial coherence length of the second laser flux, on one another.

First claim

What is claimed is:

1. A laser radiation system comprising:
a laser apparatus configured to output a first pulse laser flux;
a first optical system configured to shape a beam cross-sectional shape of the first pulse laser flux to convert the first pulse laser flux into a second pulse laser flux and transfer the second pulse laser flux onto a transfer position;
a multimirror device arranged at the transfer position of the first optical system and including a plurality of mirrors, configured to be capable of controlling an angle of an attitude of each of the plurality of mirrors, and configured to divide the second pulse laser flux into a plurality of pulse laser fluxes and reflect the plurality of pulse laser fluxes in a plurality of directions to produce the plurality of divided pulse laser fluxes;
a Fourier transform optical system configured to focus the plurality of divided pulse laser fluxes; and
a control section configured to control the angle of the attitude of each of the plurality of mirrors in such a way that the Fourier transform optical system superimposes the plurality of pulse laser fluxes, which are divided by the mirrors separate from each other by at least a spatial coherence length of the second pulse laser flux, on one another,
wherein the control section is configured to
set a plurality of coherence cells based on the spatial coherence length of the second pulse laser flux,
segment an arrangement of the plurality of mirrors of the multimirror device into a plurality of mirror arrangement regions in correspondence with the coherence cells to specify the mirror arrangement regions including the plurality of mirrors for each of the coherence cells, and
select one mirror from each of the plurality of coherence cells and control the angle of the attitude of each of the plurality of mirrors in such a way that the selected mirrors reflect the pulse laser fluxes in the same direction, and
wherein the coherence cells are each a region larger than or equal to a quadrangle having a first side having a spatial coherence length in a first axial direction out of two axial directions perpendicular to each other and a second side having a spatial coherence length in a second axial direction out of the two axial directions.

2. The laser radiation system according to claim 1 ,
wherein the laser apparatus is a discharge-excitation-type laser apparatus.

3. The laser radiation system according to claim 1 , further comprising
a beam characteristic measurer configured to measure beam characteristics of the second pulse laser flux,
wherein the control section is configured to control the angle of the attitude of each of the plurality of mirrors based on a result of the measurement performed by the beam characteristic measurer.

4. The laser radiation system according to claim 3 ,
wherein the beam characteristic measurer is a beam profiler configured to measure an optical intensity distribution of a beam cross section of the second pulse laser flux.

5. The laser radiation system according to claim 4 ,
wherein the control section is configured to control the angle of the attitude of each of the plurality of mirrors based on an optical intensity in each position in the beam cross section measured by the beam profiler.

6. The laser radiation system according to claim 3 ,
wherein the beam characteristic measurer is a wavefront sensor configured to measure a traveling direction and an optical intensity of a pulse laser flux in each position in a beam cross section of the second pulse laser flux.

7. The laser radiation system according to claim 6 ,
wherein the control section is configured to control the angle of the attitude of each of the plurality of mirrors based on the traveling direction and the optical intensity of the pulse laser flux in each position in the beam cross section measured by the wavefront sensor.

8. The laser radiation system according to claim 1 ,
wherein the first optical system includes a beam shaping optical system.

9. The laser radiation system according to claim 1 ,
wherein the first optical system includes a beam collimator optical system.

10. The laser radiation system according to claim 1 ,
wherein the first optical system includes a low-coherence optical system.

11. The laser radiation system according to claim 10 ,
wherein the low-coherence optical system is an optical element configured to spatially produce an optical path difference greater than or equal to a temporal coherence length between pulse laser fluxes in different positions in a laser beam.

12. The laser radiation system according to claim 1 ,
wherein an angle at which the second pulse laser flux is incident on the multimirror device is so set that an optical path difference ΔLg of pulse laser fluxes into which the second pulse laser flux reflected off the multimirror device is divided is greater than or equal to a temporal coherence length ΔLt of the second pulse laser flux.

13. The laser radiation system according to claim 1 ,
further comprising a projection optical system configured to cause a first image formed in a focal position of the Fourier transform optical system to be formed as a second image on a surface of a processing receiving material.

14. The laser radiation system according to claim 13 ,
further comprising a mask in which an opening smaller than a focused beam that forms the first image is disposed in a position of the first image.

15. The laser radiation system according to claim 14 ,
wherein 0.3<Dm/DI<0.99 is satisfied, where Dm represents a diameter of the opening provided in the mask, and DI represents a diameter of the focused beam that forms the first image.

16. A method for manufacturing an electronic device, the method comprising:
producing a pulse laser flux by using a laser radiation system; and
processing a processing receiving material by irradiating the processing receiving material with the pulse laser flux produced by the laser radiation system,
the laser radiation system including
a laser apparatus configured to output a first pulse laser flux,
a first optical system configured to shape a beam cross-sectional shape of the first pulse laser flux to convert the first pulse laser flux into a second pulse laser flux and transfer the second pulse laser flux onto a transfer position,
a multimirror device arranged at the transfer position of the first optical system and including a plurality of mirrors, configured to be capable of controlling an angle of an attitude of each of the plurality of mirrors, and configured to divide the second pulse laser flux into a plurality of pulse laser fluxes and reflect the plurality of pulse laser fluxes in a plurality of directions to produce the plurality of divided pulse laser fluxes,
a Fourier transform optical system configured to focus the plurality of divided pulse laser fluxes, and
a control section configured to control the angle of the attitude of each of the plurality of mirrors in such a way that the Fourier transform optical system superimposes the plurality of pulse laser fluxes, which are divided by the mirrors separate from each other by at least a spatial coherence length of the second pulse laser flux, on one another,
wherein the control section is configured to
set a plurality of coherence cells based on the spatial coherence length of the second pulse laser flux,
segment an arrangement of the plurality of mirrors of the multimirror device into a plurality of mirror arrangement regions in correspondence with the coherence cells to specify the mirror arrangement regions including

Assignees

• Gigaphoton Inc

Inventors

• Suzuki Akiyoshi
• Wakabayashi Osamu

Classifications

• H10P76/2042

  using lasers · CPC title

• G02B19/0019 Primary

  having reflective surfaces only (e.g. louvre systems, systems with multiple planar reflectors) · CPC title

• G01J1/4257

  applied to monitoring the characteristics of a beam, e.g. laser beam, headlamp beam (monitoring arrangements for lasers in general H01S3/0014) · CPC title

• G02B5/001

  Axicons, waxicons, reflaxicons · CPC title

• G02B19/0047

  for use with a light source (G02B19/009, G02B19/0095 take precedence; details of lighting devices in general F21V; non-semiconductor lasers having optical devices external to the laser cavity H01S3/005) · CPC title