JP2004351466A - Laser beam machining method and laser beam machining apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser beam machining method and a laser beam machining apparatus with which the wastefulness of the working time is saved and the working efficiency is improved. <P>SOLUTION: In the laser beam machining apparatus 1, firstly, the laser beam (short pulse beam) 7 from a high intense laser beam 2 is set so as to condense under a material S to be machined, fixed to a stage 5 for precisely shifting through a beam positional adjusting part 3 and an objective lens 4. Successively, the stage 5 for precisely shifting, fixed with the material S to be machined, is shifted to an X-axial or Y-axial direction and simultaneously, shifted to + direction of Z-axis and the beam condensing point of the laser beam (short pulse beam) 7 is scanned to the back surface (Z-surface) of the material S to be machined. In this way, on the back surface of the material S to be machined, the laser beam machining is performed with a beam inductive breakage at a position positioned with the condensed beam point of the laser beam (short pulse beam) 7. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laser processing method and a laser processing apparatus for processing using the high energy density of laser light.
[0002]
[Prior art]
Conventionally, in the technical field of laser processing methods and laser processing apparatuses, when laser light having a pulse width of about picoseconds to femtoseconds is irradiated onto a material to be processed, high-quality material removal can be achieved by light-induced destruction by laser light. It is known that this can be done (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP 2002-205179 A
[0004]
That is, in the photo-induced breakdown, ionization of the processing site, proliferation of free electrons, induction breakdown, plasma formation, evaporation, and the like occur, so that there is almost no thermal influence around the processing site.
[0005]
[Problems to be solved by the invention]
However, in many cases, a titanium sapphire laser is used as a laser that oscillates a laser beam, and the wavelength of the laser beam is in the 800 nm band. For example, a silicon or gallium arsenide group III-V semiconductor material is coated. When the processing material is used, the laser beam is absorbed by the processing material, so that only the surface of the processing material can be processed.
[0006]
Furthermore, when the work site on the surface of the work material is photo-induced destruction, the vaporized material becomes plasma and diffuses around the work site to shield the laser beam, so that the plasma is sufficiently scattered. Until then, irradiation of the next laser beam (short pulse light) has to be waited, and for this reason, it is necessary to lower the repetition frequency of the pulse, resulting in a waste of processing time.
[0007]
Therefore, the present invention has been made in view of the above-described points, and an object of the present invention is to provide a laser processing method and a laser processing apparatus that improve processing efficiency by eliminating processing time waste.
[0008]
[Means for Solving the Problems]
The invention according to claim 1 made to solve this problem is a laser processing method, wherein laser light oscillated from a laser is transmitted from the surface of the material to be processed and condensed on the back surface of the material to be processed. Then, the laser beam is scanned or the workpiece material is moved to cause light-induced breakdown in the laser beam condensing portion of the workpiece material.
[0009]
The invention according to claim 2 is the laser processing method according to claim 1, characterized in that gas is blown onto the back surface side of the material to be processed.
The invention according to claim 3 is the laser processing method according to claim 1, characterized in that the back side of the material to be processed is decompressed.
[0010]
The invention according to claim 4 is the laser processing method according to any one of claims 1 to 3, wherein the laser medium of the laser is a fiber doped with at least erbium, and the laser The light wavelength has a component at 1.5 μm.
[0011]
The invention according to claim 5 is the laser processing method according to any one of claims 1 to 4, wherein the material to be processed is silicon or a gallium arsenide group III-V semiconductor. It is characterized by being one of a material and a glass material.
[0012]
The invention according to claim 6 is a laser processing method, wherein a laser beam oscillated from a laser whose fiber is a fiber doped with erbium is used as the laser light, and a silicon or gallium arsenide group III-V semiconductor material, glass After irradiating any one of the materials to be processed, the laser beam is scanned or the workpiece material is moved, thereby causing light-induced destruction at the laser beam condensing portion of the workpiece material. It is characterized by that.
[0013]
The invention according to claim 7 is the laser processing apparatus, wherein the laser light oscillated from the laser is transmitted from the surface of the material to be processed and condensed on the back surface of the material to be processed, and then the laser light It is characterized by causing light-induced destruction at a condensing part of the laser beam in the work material by scanning or moving the work material.
[0014]
The invention according to claim 8 is the laser processing apparatus according to claim 7, characterized in that gas is blown onto the back surface side of the material to be processed.
The invention according to claim 9 is the laser processing apparatus according to claim 7, characterized in that the back side of the material to be processed is decompressed.
[0015]
The invention according to claim 10 is the laser processing apparatus according to any one of claims 7 to 9, wherein a laser medium of the laser is a fiber doped with at least erbium, and the laser The light wavelength has a component at 1.5 μm.
[0016]
The invention according to claim 11 is the laser processing apparatus according to any one of claims 7 to 10, wherein the material to be processed is silicon or a gallium arsenide group III-V semiconductor. It is characterized by being one of a material and a glass material.
[0017]
The invention according to claim 12 is the laser processing apparatus, wherein the laser light oscillated from the laser whose laser medium is a fiber doped with erbium is converted into silicon or a gallium arsenide group III-V semiconductor material, glass After irradiating any one of the materials to be processed, the laser beam is scanned or the workpiece material is moved, thereby causing light-induced destruction at the laser beam condensing portion of the workpiece material. It is characterized by that.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an outline of the laser processing apparatus of the present embodiment. As shown in FIG. 1, the laser processing apparatus 1 according to the present embodiment includes a high-intensity laser 2, a beam position adjusting unit 3, an objective lens 4 of about 10 times, a precision moving stage 5, a control controller 6, and the like. Have.
[0019]
And in the laser processing apparatus 1 of this Embodiment, the workpiece material S can be laser-processed by performing the following operation with the control controller 6 grade | etc.,. That is, first, a processing material S (for example, a thickness) of laser light (short pulse light) 7 from the high-intensity laser 2 is fixed to the precision movement stage 5 via the beam position adjustment unit 3 and the objective lens 4. Is set so as to collect light under a 300 μm silicon substrate. Next, the precision movement stage 5 on which the work material S is fixed is moved in the X-axis or Y-axis direction and simultaneously in the Z-axis + direction, and as shown in FIG. The condensing point Q of the pulsed light 7 is scanned to the back surface (Z-plane) of the workpiece S. As a result, laser processing by light-induced breakdown is performed on the back surface of the material S to be processed at the position where the condensing point Q of the laser light (short pulse light) 7 is located.
[0020]
At this time, the precision movement stage 5 to which the work material S is fixed is moved in the X-axis or Y-axis direction, so that the condensing point Q of the laser light (short pulse light) 7 is set to the back surface of the work material S. Can be freely laser processed on the back surface of the material S to be processed. Further, the focusing point Q of the laser beam (short pulse light) 7 can be scanned inside the workpiece material S by moving the precision moving stage 5 to which the workpiece material S is fixed in the Z-axis direction. Thus, the entire workpiece material S can be freely laser processed.
[0021]
Of course, in the laser processing apparatus 1 of the present embodiment, in order to start laser processing by light-induced breakdown from the back surface of the material S to be processed, the laser light (short pulse light) 7 from the high-intensity laser 2 is It must have high strength while passing through the processing material S (for example, a silicon substrate having a thickness of 300 μm). Therefore, in the high-intensity laser 2 used in the laser processing apparatus 1 of the present embodiment, a laser beam (short) having a wavelength of 1560 nm, an average output of 160 mW, a repetition frequency of 10 kHz to 200 kHz, and a pulse width of 400 to 600 fs. (Pulse light) 7 is output. Therefore, hereinafter, the high-intensity laser 2 used in the laser processing apparatus 1 of the present embodiment will be described.
[0022]
FIG. 4 is a diagram showing an outline of the high-intensity laser 2 used in the laser processing apparatus 1 of the present embodiment. As shown in FIG. 4, the high-intensity laser 2 includes a femtosecond laser oscillator 11, an isolator 12, a 4-port circulator 13, a fiber grating 14, an amplification unit 18, a pulse compressor 17 such as a diffraction grating pair, and the like. Yes. Further, as shown in FIG. 5, the amplifying unit 18 includes wavelength division multiplexing couplers (hereinafter referred to as “WDM”) 21a to 21f, isolators 22a to 22f, and a single-mode laser diode having an oscillation wavelength of 1.48 μm (hereinafter referred to as “WDM”). 23a to 23f, single mode erbium-doped amplification fibers (hereinafter referred to as “EDF”) 24a to 24e for normal output and high output, Faraday rotor mirror (hereinafter referred to as “FRM”) 15 The short pulse light supplied from the femtosecond laser oscillator 11 can be amplified in the form of a reciprocating path (double path).
[0023]
In this regard, the femtosecond laser oscillator 11 is an erbium fiber laser and outputs laser light (short pulse light) having a time width in the femtosecond range. As shown in FIG. 4, the laser light (short pulse light) output from the femtosecond laser oscillator 11 is incident on the fiber grating 14 via the isolator 12 and the 4-port circulator 13.
[0024]
However, since the position where the laser beam (short pulse light) is reflected differs depending on the wavelength of the fiber grating 14, the laser light (short pulse light) incident / reflected / output by the fiber grating 14 is chirped. It becomes a state. At this time, since the time width of the chirped laser beam (short pulse beam) is extended from, for example, 100 femtoseconds to 100 picoseconds, compared with the time when it is output from the femtosecond laser oscillator 11, Its peak power is lowered.
Then, the chirped laser light (short pulse light) is incident on the amplifier 18 and passes through the EDF 24a via the WDM 21a to which the single mode LD 23a is connected as shown in FIG. Is done.
[0025]
The WDM 21a has three ports, a 1.48 μm port, a 1.55 μm port, and a common port. A single mode LD 23a is connected to the 1.48 μm port through an isolator 22a, and the 1.55 μm port is 1.55 μm. Chirped short pulse light is incident on the port, and one end of the EDF 24a is connected to the common port.
[0026]
The WDM 21b also has three ports, a 1.48 μm port, a 1.55 μm port, and a common port. A single mode LD 23b is connected to the 1.48 μm port via an isolator 22b, and the 1.55 μm port is 1.55 μm. The other end of the EDF 24a is connected to the port, and one end of the EDF 24b is connected to the common port.
[0027]
Similarly, each of the WDMs 21c, 21d, and 21e has three ports, a 1.48 μm port, a 1.55 μm port, and a common port. For the 1.48 μm port, single mode LDs 23c, 23d, and 23e are provided. The other ends of the EDFs 24b, 24c, and 24d are connected to the 1.55 μm port, respectively, and one end of the EDFs 24c, 24d, and 24e is connected to the common port. Each is connected.
[0028]
The WDM 21f also has three ports, a 1.48 μm port, a 1.55 μm port, and a common port. A single mode LD 23f is connected to the 1.48 μm port via an isolator 22f. The FRM 15 is connected to the 55 μm port, and the other end of the EDF 24e is connected to the common port.
[0029]
As a result, the amplification unit 18 can use six single mode LDs 23a, 23b, 23c, 23d, 23e, and 23f in series, so that even the core pump using the single mode LD can increase the amount of excitation light. . Further, the FRM 15 is connected to the other end side of the EDF 24e to form a reciprocating path (double path) form, and the deflection surface of the short pulse light can be shifted by 90 ° with the FRM 15, so that the five EDFs 24a, 24b, 24c, 24d , 24e can be output by a deflection-dependent four-port circulator 13 after being reciprocated, and the pulse width is shortened by a pulse compressor 17 such as a diffraction grating pair and then output to the outside.
[0030]
That is, in the high-intensity laser 2, as shown in FIG. 4, when the laser light (short pulse light) from the femtosecond laser oscillator 11 is incident on the fiber grating 14, it is chirped and the time width is expanded. Power is lowered. Therefore, if the laser light (short pulse light) from the fiber grating 14 is incident on the fiber amplifier 18 (see FIG. 5), the amplification of the laser light (short pulse light) is performed under the condition that the nonlinear phenomenon hardly occurs. It can be performed. In the fiber amplifying unit 18 (see FIG. 5), five EDFs 24a, 24b, 24c, 24d, and 24e are connected in series, and single-mode LDs 23a, 23d from one end of each EDF 24a, 24b, 24c, 24d, and 24e. 23b, 23c, 23d, 23e, and 23f are respectively pumped, and laser light (short pulse light) is amplified every time it passes through each EDF 24a, 24b, 24c, 24d, and 24e. ) Amplification efficiency can be increased. Further, since each EDF 24a, 24b, 24c, 24d, and 24e is in a normal dispersion, even if laser light (short pulse light) passes through each EDF 24a, 24b, 24c, 24d, and 24e, The time width is not compressed, and the occurrence of nonlinear phenomena in the amplification of short pulse light can be suppressed.
[0031]
Furthermore, the femtosecond laser oscillator 11 used in the high intensity laser 2 will be described here. FIG. 6 is a diagram showing an outline of the femtosecond laser oscillator 11. As shown in FIG. 6, the femtosecond laser oscillator 11 includes a femtosecond pulse oscillator 110, an optical amplifier 130, and the like.
[0032]
The femtosecond pulse oscillator 110 includes an optical communication LD 111 as a pumping light source, an erbium-doped optical amplification fiber 112 as a laser medium, a lens 113, a Faraday rotator 114, a mirror 115, a lens 116, and a Faraday. A rotor 117, a quarter wavelength plate 118, a half wavelength plate 119, a beam splitter (hereinafter referred to as “PBS”) 120, a lens 121, a saturable absorber 122, and the like are included. In this respect, in the femtosecond pulse oscillator 110, the two Faraday rotators 114 and 117 are arranged at both ends of the optical amplifying fiber 112 constituting the linear cavity, so that the optical polarization plane drift caused by vibration and temperature change can be prevented. It has a structure that compensates for it, and has a strong structure against environmental changes.
[0033]
In the femtosecond pulse oscillator 110, light including various wavelengths is amplified by reciprocating between a gold mirror (not shown) provided on the end face of the saturable absorber 122 and the mirror 115 many times. In addition, when a standing wave in a phase-matched state (mode-locked state) is formed, an optical pulse train that is a laser beam is output toward the optical amplifier 130 by the action of both wavelength plates 118 and 119 and the PBS 120. .
[0034]
On the other hand, the optical amplifier 130 includes a PBS 132, a half-wave plate 133, a quarter-wave plate 134, a Faraday rotator 135, a lens 136, an optical amplification fiber 137 doped with erbium, a lens 138, a Faraday rotator 139, and a mirror 140. And an optical communication LD 141 as an excitation light source. In this respect, the optical amplifier 130 also has a structure that compensates for optical polarization plane drift caused by vibration and temperature change by arranging two Faraday rotators 135 and 139 at both ends of the optical amplifying fiber 137. It has a strong structure against environmental changes.
[0035]
In the optical amplifier 130, the optical pulse train from the femtosecond pulse oscillator 110 is reflected by the PBS 132, passed toward the optical amplification fiber 137, then reflected by the mirror 115, and passed through the optical amplification fiber 137 again. As a result, amplification accompanied by pulse compression is performed, and the output of the femtosecond laser oscillator 11 used in the high-intensity laser 2 (see FIG. 4) is output to the outside by the action of both the wave plates 133 and 134 and the PBS 132. Yes. The optical pulse train at this time has a center wavelength of 1560 nm, a repetition frequency of 48.5 MHz, a pulse width of 105 fsec, and an average output of 62.5 mW.
[0036]
In FIG. 6, for convenience of explanation, an optical pulse train from the PBS 132 toward the lens 136 (and thus the optical amplification fiber 137) and an optical pulse train from the lens 136 (that is, the optical amplification fiber 137) toward the PBS 132 are shown separately. However, in practice, the optical paths of both optical pulse trains are superimposed.
[0037]
Here, returning to the description of the high-intensity laser 2, as shown in FIG. 4, the laser light (short pulse light) output from the femtosecond laser oscillator 11 used in the high-intensity laser 2 is a pulse (not shown). After the repetition frequency can be varied from 1 kHz to 1 MHz by the picker, the light is incident on the isolator 12. As described above, the laser light (short pulse light) from the high-intensity laser 2 has a wavelength of 1560 nm and an average output of 160 mW.
[0038]
Further, even if the repetition frequency was varied by the pulse picker (not shown), the average output of the laser light (short pulse light) from the high-intensity laser 2 was hardly changed in the range from 100 kHz to 500 kHz. At this time, the energy per pulse of the laser light (short pulse light) from the high-intensity laser 2 is, for example, 1.6 μJ when the repetition frequency is 100 kHz, and 0.3 μJ when the repetition frequency is 500 kHz, The pulse time width is 400 to 600 fs.
[0039]
And in the laser processing apparatus 1 of this Embodiment, after starting the laser processing by light-induced destruction from the back surface of the material S to be processed (for example, a silicon substrate having a thickness of 300 μm), the above-described shutter (not shown) is used. The plasma generated when the laser beam (short pulse beam) from the high-intensity laser 2 is irradiated at a repetition frequency of 200 kHz is generated from the back surface of the material S to be processed (for example, a silicon substrate having a thickness of 300 μm). Since laser light (short pulse light) from the high-intensity laser 2 irradiated from the surface of the processing material S (for example, a silicon substrate having a thickness of 300 μm) is not shielded, laser processing is performed at a high repetition frequency. Can increase the processing speed.
[0040]
As described above in detail, in the laser processing apparatus 1 of the present embodiment and the laser processing method performed by the laser processing apparatus 1, the femtosecond pulse oscillator of the femtosecond laser oscillator 11 used in the high intensity laser 2 is used. The laser medium 110 is an optical amplification fiber 112 doped with erbium, and the wavelength of the laser light (pulse light) from the high-intensity laser 2 is in the 1560 nm (1.5 μm) band. That is, the wavelength of the laser light (pulse light) has a component at 1.5 μm. Further, the material to be processed S is, for example, a silicon substrate having a thickness of 300 μm. Therefore, the laser light (pulse light) from the high-intensity laser 2 can pass through the workpiece S.
[0041]
And in the laser processing apparatus 1 of this Embodiment and the laser processing method implemented with the laser processing apparatus 1, as shown in FIG. 2, the laser beam (pulse light) from the high intensity laser 2 is processed material S. Then, the work material is moved through the precision movement stage 5 to which the work material S is fixed. As a result, the laser beam (pulse light) from the high-intensity laser 2 is scanned to cause light-induced destruction at the condensing part of the laser beam (pulse light) in the material S to be processed. At this time, since the condensing part of the material to be processed S is on the back surface of the material to be processed S, the plasma vaporized by the condensing part of the material to be processed S at the time of light-induced breakdown is generated on the back surface of the material to be processed S. Laser light (pulse light) that diffuses to the periphery and irradiates the workpiece material S from the surface of the workpiece material S is not shielded. Thereby, it is not necessary to wait for the irradiation of the laser beam (pulse light) until the plasma is sufficiently scattered, and more specifically, the laser beam (pulse) oscillated from the high intensity laser 2 having a high repetition frequency (pulse number). Light) can also be performed, so that the processing time is saved, and the processing cost can be reduced.
[0042]
The scanning of the laser light (pulse light) from the high-intensity laser 2 is not limited to the precision movement stage 5 on which the material S to be processed is fixed, but instead, an optical system device may be used. Good.
[0043]
Further, in the laser processing apparatus 1 and the laser processing method performed by the laser processing apparatus 1 according to the present embodiment, as shown in FIG. 3, even if the material to be processed S is a gallium arsenide substrate, the same operation is performed.・ Effects can be obtained. Further, in FIG. 3, the holder jig 8 for fixing the workpiece material S is mounted on the precision moving stage 5, and the inner space 9 of the holder jig 8 is decompressed by a pump (not shown) while the workpiece material is being reduced. Laser processing of S is performed. Therefore, in this case, when the internal space 9 of the holder jig 8 is evacuated, the workpiece S comes into close contact with the internal space 9 of the holder jig 8 and at the same time, the internal space of the holder jig 8. The plasma diffused to 9 is removed (see reference numeral 10 in FIG. 3).
[0044]
That is, in the laser processing apparatus 1 of the present embodiment and the laser processing method performed by the laser processing apparatus 1, as shown in FIG. 3, the back side of the material S to be processed is depressurized. Even if plasma is generated on the back surface side of the work material S, the work material S does not float, and the position of the work material S is always fixed, so that highly accurate processing can be performed. . Furthermore, since the generated plasma is efficiently diffused, it can be prevented from adhering to the back surface of the material S to be processed. In this respect, even when the material S to be processed is a silicon substrate, the same operation and effect can be obtained.
[0045]
In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning.
For example, in the laser processing apparatus 1 of the present embodiment and the laser processing method performed by the laser processing apparatus 1, the material S to be processed was a silicon substrate or a gallium arsenide substrate, but other III-V semiconductors It may be a material.
In this regard, semiconductor chips in recent years have been miniaturized due to high density, and therefore, the problem of heat dissipation has become apparent, and in order to solve this problem, the substrate has been made thinner. For this reason, it has become difficult to divide the substrate by dicing or cleaving at present, and laser processing has been desired. However, in normal laser processing, since it is processing by heat, there is a possibility that heat denaturation is given to the periphery of the processing site and damage to the semiconductor chip.
On the other hand, the laser processing apparatus 1 of the present embodiment and the laser processing method performed by the laser processing apparatus 1 can perform clean laser processing without a thermal history, and thus are suitable for substrate division. it can. Furthermore, not only the division of the substrate but also the serial number and the model number can be easily engraved on a part of the semiconductor chip, which is useful for tracking the semiconductor chip in the market.
[0046]
Further, the material S to be processed is not limited to a semiconductor material, and may be an optical glass material such as a substrate such as BK7. In this case, for example, a serial number or the like can be engraved on the glass of an automobile, which can be useful for theft of an automobile or identification of an illegally neglected automobile number.
[0047]
Moreover, in the laser processing apparatus 1 of this Embodiment and the laser processing method implemented with the laser processing apparatus 1, as shown in FIG. 3, the jig | tool 8 for holders for fixing the workpiece S for precision movement is used. The plasma diffused in the internal space 9 of the holder jig 8 is removed by carrying out laser processing of the workpiece S while being mounted on the stage 5 and depressurizing the internal space 9 of the holder jig 8 with a pump (not shown). However, the generated plasma is efficiently diffused to prevent the plasma from adhering to the back surface of the work material S, but this point does not float on the precision moving stage 5. Since the generated plasma can be efficiently diffused even when a gas from an air compressor (not shown) or a cylinder is blown against the workpiece S fixed in this manner, the back surface of the workpiece S It is prevented from adhering.
[0048]
Moreover, in the laser processing apparatus 1 of this Embodiment and the laser processing method implemented with the laser processing apparatus 1, it replaces with what is shown in FIG. 4, and uses what is shown in FIG. Also good. In this regard, the high-intensity laser 2 in FIG. 7 is a high-energy femtosecond fiber laser using a chirped pulse amplifier in the wavelength 1560 nm band, and in addition to the femtosecond laser oscillator 11 described above, a chirped fiber 41, a lens 42, an isolator 43, a first pump laser diode 44, a multimode erbium-doped fiber amplifier 45, a second pump laser diode 46, a pulse compressor 47, beam splitters P1, P2, P3, P4, P5, P6, and the like. The laser light (pulse light) amplified to an average output of 13 W with a pulse width of 5 ps is compressed by a pulse compressor 47 to an average output of 6.5 W with a pulse width of 100 fs and output.
[0049]
【The invention's effect】
In the laser processing method and laser processing apparatus of the present invention, since the condensing part of the work material is on the back surface of the work material, the plasma vaporized by the condensing part of the work material during the light-induced breakdown The laser beam that diffuses around the back surface of the processing material and irradiates the processing material from the surface of the processing material is not shielded. Thereby, it is not necessary to wait for the irradiation of the laser beam until the plasma is sufficiently scattered, and more specifically, it is possible to perform the irradiation of the laser beam oscillated from the laser having a high repetition frequency (number of pulses). Processing time is saved, but processing costs can be reduced.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a laser processing apparatus according to an embodiment of the present invention.
FIG. 2 scans the condensing point of laser light (short pulse light) from a high-intensity laser up to the back surface of the work material fixed to a precision moving stage in the laser processing apparatus according to the embodiment of the present invention. It is the elements on larger scale which showed the outline at the time of being done.
FIG. 3 shows a laser beam machining apparatus according to an embodiment of the present invention in which a condensing point of a laser beam (short pulse beam) from a high-intensity laser is fixed on a jig for holder of a stage for precision movement. It is the elements on larger scale which showed the outline at the time of scanning to the back.
FIG. 4 is a view showing an outline of a high-intensity laser used in a laser processing apparatus according to an embodiment of the present invention.
FIG. 5 is a diagram showing an outline of an amplification unit of a high-intensity laser in a laser processing apparatus according to an embodiment of the present invention.
FIG. 6 is a diagram showing an outline of a femtosecond laser oscillator used in a high-intensity laser in a laser processing apparatus according to an embodiment of the present invention.
FIG. 7 is a view showing an outline of a high-intensity laser used in a laser processing apparatus according to an embodiment of the present invention.
[Explanation of symbols]
1 Laser processing equipment
2 High intensity laser
3 Beam position adjustment unit
4 Objective lens
5 Stage for precision movement
6 Controller for control
7 Laser light (short pulse light)
8 Jig for holder
9 Internal space of holder jig
Condensing point of Q laser light (short pulse light)
S Work material

Claims (12)

After the laser beam oscillated from the laser is transmitted from the surface of the material to be processed and condensed on the back surface of the material to be processed, the laser beam is scanned or the material to be processed is moved. A laser processing method comprising causing light-induced destruction at a condensing portion of the laser beam in the method. A laser processing method according to claim 1,
A laser processing method, characterized in that a gas is blown onto a back surface side of the material to be processed. A laser processing method according to claim 1,
A laser processing method, wherein the back side of the material to be processed is depressurized. A laser processing method according to any one of claims 1 to 3,
A laser processing method, wherein the laser medium of the laser is a fiber doped with at least erbium, and the wavelength of the laser light has a component of 1.5 μm. A laser processing method according to any one of claims 1 to 4,
The laser processing method, wherein the material to be processed is any one of silicon, a gallium arsenide group III-V semiconductor material, and a glass material. Laser light emitted from a laser whose laser medium is a fiber doped with erbium is irradiated onto any one of silicon, a gallium arsenide group III-V semiconductor material, and a glass material, and then the laser. A laser processing method characterized by causing light-induced destruction at a condensing portion of the laser light in the material to be processed by scanning light or moving the material to be processed. After the laser beam oscillated from the laser is transmitted from the surface of the material to be processed and condensed on the back surface of the material to be processed, the laser beam is scanned or the material to be processed is moved. Causing laser-induced destruction at the laser beam condensing part. The laser processing apparatus according to claim 7,
A laser processing apparatus, characterized in that a gas is blown onto a back surface side of the material to be processed. The laser processing apparatus according to claim 7,
A laser processing apparatus, characterized in that the back side of the material to be processed is decompressed. A laser processing apparatus according to any one of claims 7 to 9,
A laser processing apparatus, wherein the laser medium of the laser is a fiber doped with at least erbium, and the wavelength of the laser light has a component of 1.5 μm. A laser processing apparatus according to any one of claims 7 to 10,
The laser processing apparatus, wherein the material to be processed is one of silicon, a gallium arsenide group III-V semiconductor material, and a glass material. Laser light emitted from a laser whose laser medium is a fiber doped with erbium is irradiated onto any one of silicon, a gallium arsenide group III-V semiconductor material, and a glass material, and then the laser. A laser processing apparatus characterized by causing light-induced destruction at a condensing portion of the laser light in the material to be processed by scanning light or moving the material to be processed.

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