US-20260124698-A1 - LASER PROCESSING APPARATUS, CONTROL METHOD OF LASER PROCESSING APPARATUS, AND ELECTRONIC DEVICE MANUFACTURING METHOD

US20260124698A1US 20260124698 A1US20260124698 A1US 20260124698A1US-20260124698-A1

Abstract

A laser processing apparatus includes a first actuator moving a light shielding plate in a direction perpendicular to an optical axis of a light concentrating optical system, a second actuator capable of generating high density patterns densified by moving a multi-point pattern at a movement pitch shorter than a grid interval of the multi-point pattern, a third actuator moving a workpiece in the direction perpendicular to the optical axis, and a laser processing processor. At each step position in a processing area changed by controlling the third actuator, the laser processing processor selects one of the high density patterns, each having a different number of rows or a different number of columns, and controls the second actuator and the laser device to perform irradiation with the selected pattern, so that drilling is performed on a surface of the workpiece only in the processing area where drilling is required.

Inventors

Yasufumi Kawasuji
Osamu Wakabayashi
Akiyoshi Suzuki

Assignees

GIGAPHOTON INC.

Dates

Publication Date: 20260507
Application Date: 20260102

Claims (17)

1 . A laser processing apparatus comprising: a diffractive optical element configured to divide first laser light output from a laser device into a plurality of beams of second laser light and output the second laser light; a light concentrating optical system configured to generate a grid-like multi-point pattern in which a plurality of light concentration spots are arranged in a row direction and a column direction by concentrating the plurality of beams of second laser light; a light shielding plate capable of shielding at least a part of the multi-point pattern; a first actuator configured to move the light shielding plate in a direction perpendicular to an optical axis of the light concentrating optical system; a second actuator capable of generating high density patterns densified by moving the multi-point pattern at a movement pitch shorter than a grid interval of the multi-point pattern; a third actuator configured to move a workpiece in the direction perpendicular to the optical axis; and a laser processing processor configured to, at each of step positions in a processing area changed by controlling the third actuator, select one of the high density patterns being at least four patterns, each having a different number of rows or a different number of columns, and control the second actuator and the laser device to perform irradiation with the selected pattern, so that drilling is performed on a surface of the workpiece only in the processing area where drilling is required.
2 . The laser processing apparatus according to claim 1 , wherein the laser processing processor determines at least four areas which are irradiated with the at least four high density patterns respectively so that drilling is performed only in the processing area.
3 . The laser processing apparatus according to claim 2 , wherein each of the at least four areas is a single block area.
4 . The laser processing apparatus according to claim 2 , wherein the laser processing processor controls the third actuator to change the step position of an irradiation target to the step position adjacent thereto.
5 . The laser processing apparatus according to claim 1 , wherein the first actuator is a two-axis movement stage.
6 . The laser processing apparatus according to claim 1 , wherein the second actuator and the third actuator are movement stages that move the workpiece in the direction perpendicular to the optical axis.
7 . The laser processing apparatus according to claim 1 , wherein the second actuator is a beam steering device that changes an incident angle of the first laser light incident on the diffractive optical element, and the third actuator is a movement stage that moves the workpiece in the direction perpendicular to the optical axis.
8 . The laser processing apparatus according to claim 7 , further comprising a pointing measurement device arranged on an optical path of the first laser light between the beam steering device and the diffractive optical element, and configured to measure a pointing of the first laser light.
9 . The laser processing apparatus according to claim 8 , wherein the laser processing processor performs feedback control on the incident angle of the first laser light incident on the diffractive optical element based on a measurement value of the pointing by the pointing measurement device.
10 . The laser processing apparatus according to claim 1 , wherein the workpiece is arranged such that the surface coincides with a focal plane of the light concentrating optical system.
11 . The laser processing apparatus according to claim 1 , further comprising a transfer imaging optical system that forms a transfer image of the multi-point pattern generated by the light concentrating optical system on the surface.
12 . The laser processing apparatus according to claim 11 , wherein the transfer imaging optical system is a reduced transfer imaging optical system that reduces the multi-point pattern and forms a transfer image thereof on the surface.
13 . The laser processing apparatus according to claim 12 , wherein the light shielding plate is arranged on a focal plane of the light concentrating optical system.
14 . The laser processing apparatus according to claim 13 , wherein the first actuator is a two-axis movement stage, the second actuator is a beam steering device that changes an incident angle of the first laser light incident on the diffractive optical element, and the third actuator is a movement stage that moves the workpiece in the direction perpendicular to the optical axis.
15 . The laser processing apparatus according to claim 1 , wherein the laser processing processor controls the first actuator and the second actuator based on a data table in which a relationship between a control value of the first actuator and a control value of the second actuator for generating the at least four high density patterns is defined.
16 . A control method of a laser processing apparatus, comprising: at each of step positions in a processing area changed by controlling a third actuator, selecting one of high density patterns being at least four patterns, each having a different number of rows or a different number of columns, and controlling a second actuator and a laser device to perform irradiation with the selected pattern, so that drilling is performed on a surface of a workpiece only in the processing area where drilling is required, the selecting and the controlling being performed by a laser processing processor, and the laser processing apparatus including: a diffractive optical element configured to divide first laser light output from the laser device into a plurality of beams of second laser light and output the second laser light; a light concentrating optical system configured to generate a grid-like multi-point pattern in which a plurality of light concentration spots are arranged in a row direction and a column direction by concentrating the plurality of beams of second laser light; a light shielding plate capable of shielding at least a part of the multi-point pattern; a first actuator configured to move the light shielding plate in a direction perpendicular to an optical axis of the light concentrating optical system; the second actuator capable of generating the high density patterns densified by moving the multi-point pattern at a movement pitch shorter than a grid interval of the multi-point pattern; and the third actuator configured to move the workpiece in the direction perpendicular to the optical axis.
17 . An electronic device manufacturing method, comprising: forming a plurality of through holes in a glass substrate as a workpiece with a laser processing apparatus; coupling and electrically connecting an interposer and an integrated circuit chip to each other, the interposer including the glass substrate and a conductor arranged in each of the plurality of through holes; and coupling and electrically connecting the interposer and a circuit substrate to each other, the laser processing apparatus including: a diffractive optical element configured to divide first laser light output from a laser device into a plurality of beams of second laser light and output the second laser light; a light concentrating optical system configured to generate a grid-like multi-point pattern in which a plurality of light concentration spots are arranged in a row direction and a column direction by concentrating the plurality of beams of second laser light; a light shielding plate capable of shielding at least a part of the multi-point pattern; a first actuator configured to move the light shielding plate in a direction perpendicular to an optical axis of the light concentrating optical system; a second actuator capable of generating high density patterns densified by moving the multi-point pattern at a movement pitch shorter than a grid interval of the multi-point pattern; a third actuator configured to move a workpiece in the direction perpendicular to the optical axis; and a laser processing processor configured to, at each of step positions in a processing area changed by controlling the third actuator, select one of the high density patterns being at least four patterns, each having a different number of rows or a different number of columns, and control the second actuator and the laser device to perform irradiation with the selected pattern, so that drilling is performed on a surface of the workpiece only in the processing area where drilling is required.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a continuation application of International Application No. PCT/JP2023/031629, filed on Aug. 30, 2023, the entire contents of which are hereby incorporated by reference. BACKGROUND 1. Technical Field The present disclosure relates to a laser processing apparatus, a control method of a laser processing apparatus, and an electronic device manufacturing method. 2. Related Art Recently, in a semiconductor exposure apparatus, improvement in resolution has been desired for miniaturization and high integration of semiconductor integrated circuits. For this purpose, an exposure light source that outputs light having a shorter wavelength has been developed. For example, as the gas laser device for exposure, a KrF excimer laser device that outputs laser light having a wavelength of about 248.4 nm and an ArF excimer laser device that outputs laser light having a wavelength of about 193.4 nm are used. Since excimer laser light has a pulse width of about several 10 ns and a wavelength is short, excimer laser light is sometimes used for direct processing of a polymer material, a glass material, or the like. Chemical bonds in polymeric materials can be broken by excimer laser light having a photon energy higher than the bond energy. Therefore, it is known that non-heating processing of polymeric materials is possible with excimer laser light, and that the processing shape is beautiful. Further, it is known that, since glass, ceramics, and the like have high absorptance with respect to excimer laser light, even a material that is difficult to be processed with visible and infrared laser light can be processed with excimer laser light. The KrF excimer laser device and the ArF excimer laser device each have a large spectral line width of about 350 μm to 400 μm in natural oscillation light. Therefore, when a projection lens is formed of a material that transmits ultraviolet rays such as KrF laser light and ArF laser light, there is a case in which chromatic aberration occurs. As a result, the resolution may decrease. Then, a spectral line width of laser light output from the gas laser device needs to be line-narrowed to the extent that the chromatic aberration can be ignored. For this purpose, there is a case in which a line narrowing module (LNM) including a line narrowing element (etalon, grating, and the like) is provided in a laser resonator of the gas laser device to narrow a spectral line width. In the following, a gas laser device with a narrowed spectral line width is referred to as a line narrowing gas laser device. LIST OF DOCUMENTS Patent Documents Patent Document 1: US Patent Application Publication No. 2006/0289412Patent Document 2: Japanese Patent Application Publication No. 2007-268600Patent Document 3: Japanese Patent Application Publication No. 2011-161454Patent Document 4: US Patent Application Publication No. 2003/201578 SUMMARY A laser processing apparatus according to an aspect of the present disclosure includes a diffractive optical element configured to divide first laser light output from a laser device into a plurality of beams of second laser light and output the second laser light, a light concentrating optical system configured to generate a grid-like multi-point pattern in which a plurality of light concentration spots are arranged in a row direction and a column direction by concentrating the plurality of beams of second laser light, a light shielding plate capable of shielding at least a part of the multi-point pattern, a first actuator configured to move the light shielding plate in a direction perpendicular to an optical axis of the light concentrating optical system, a second actuator capable of generating high density patterns densified by moving the multi-point pattern at a movement pitch shorter than a grid interval of the multi-point pattern, a third actuator configured to move a workpiece in the direction perpendicular to the optical axis, and a laser processing processor. At each of step positions in a processing area changed by controlling the third actuator, the laser processing processor is configured to select one of the high density patterns being at least four patterns, each having a different number of rows or a different number of columns, and control the second actuator and the laser device to perform irradiation with the selected pattern, so that drilling is performed on a surface of the workpiece only in the processing area where drilling is required. A control method of a laser processing apparatus according to an aspect of the present disclosure includes, at each of step positions in a processing area changed by controlling a third actuator, selecting one of high density patterns being at least four patterns, each having a different number of rows or a different number of columns, and controlling a second actuator and a laser device to perform irradiation with the selected pattern, so that drilling is perfor