US 12,076,815 B2
Laser processing apparatus and method for processing workpiece
Masashi Shimbori, Oyama (JP); and Osamu Wakabayashi, Oyama (JP)
Assigned to Gigaphoton Inc., Tochigi (JP)
Filed by Gigaphoton Inc., Tochigi (JP)
Filed on May 4, 2021, as Appl. No. 17/307,252.
Application 17/307,252 is a continuation of application No. PCT/JP2018/045811, filed on Dec. 13, 2018.
Prior Publication US 2021/0252634 A1, Aug. 19, 2021
Int. Cl. B23K 26/073 (2006.01); B23K 26/06 (2014.01); B23K 26/0622 (2014.01); B23K 26/066 (2014.01); B23K 26/082 (2014.01)
CPC B23K 26/073 (2013.01) [B23K 26/0622 (2015.10); B23K 26/0648 (2013.01); B23K 26/066 (2015.10); B23K 26/082 (2015.10)] 11 Claims
OG exemplary drawing
 
1. A laser processing apparatus comprising:
a placement base on which a workpiece is placed;
a beam shaping optical system configured to shape laser light in such a way that a first irradiated region of a mask configured to block part of the laser light that is a region irradiated with the laser light has a rectangular shape having short edges and long edges, the beam shaping optical system further configured to be capable of causing one of a first radiation width of the first irradiated region in a direction parallel to the short edges and a second radiation width of the first irradiated region in a direction parallel to the long edges to be fixed and causing another of the first and second radiation widths to be changed;
a projection optical system configured to project a pattern on the mask onto the workpiece placed on the placement base;
a mover configured to move the first irradiated region at least in the direction parallel to the short edges to move a second irradiated region of the workpiece placed on the placement base that is a region irradiated with the laser light; and
a controller, wherein
the beam shaping optical system is configured to be capable of causing the second radiation width to be fixed and causing the first radiation width to be changed,
the controller is configured to control the beam shaping optical system in such a way that fluence of the laser light on the workpiece placed on the placement base approaches a target value by changing the first radiation width,
the laser light is pulsed laser light, and
the controller is configured to control the mover in such a way that an absolute value of a moving speed Vxm of the first irradiated region in the direction parallel to the short edges approaches a value below,
|Vxm|=f·Bx/Np,
where f represents a repetitive frequency of the pulsed laser light, Bx represents the first radiation width, and Np represents the number of pulses radiated to the same position.