JPH10166172A - Laser beam machining method and its machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser beam machining method and its machine applying a prescribed working to an object to be machined by condensing the laser beam in plurality of places and increasing energy. SOLUTION: The laser beam L0 from a laser beam source 1 is irradiated on a phase pattern plate 2, the ± primary diffracted lights L1, L2 are irradiated on a mask 4 having an opening part 4a with an illuminating optical system 3 to generate interferential strips, the light part of interferential stripes is made to coincide with the opening part 4a, the laser beam passed through the opening part is projected on the object 6 to be machined at a projective magnification with a projective optical system 5, and the object 6 to be machined is machined into the shape correspondant to the opening pattern of the mask 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing method and apparatus, and more particularly, to a laser processing method for irradiating a mask with a laser beam to project a pattern on the workpiece and processing the workpiece. And its device.

[0002]

2. Description of the Related Art A conventional laser processing apparatus is disclosed in, for example, Japanese Patent Application Laid-Open No. 61-254346. This device irradiates the mask with laser light to process the workpiece, and irradiates the mask with the laser light reflected back without passing through the opening pattern of the mask to irradiate the mask to increase the illuminance on the mask. ing. 2. Description of the Related Art In a laser processing apparatus, by increasing the illuminance by a laser beam, the processing efficiency in processing a workpiece is improved, and the processing time is reduced.

FIG. 6 shows an example of this type of laser processing apparatus. The traveling direction of the laser light 21 emitted from the laser oscillator 20 is changed by the deflection mirror 22,
Irradiation is performed on the mask 23 arranged at a slight angle to the optical axis. The laser beam 21 reflected by the mask 23 reaches the total reflection mirror 24 without returning to the deflecting mirror 22, where it is reflected again to irradiate the mask 23. The laser light is repeatedly reflected by the total reflection mirror 24 and the mask 23 to increase the illuminance on the mask 23. A predetermined opening pattern is provided on the mask 23, and the opening pattern is imaged on the workpiece 26 via the lens 25,
Can be processed into a shape corresponding to the opening pattern.

[0004]

In the above-described conventional laser processing apparatus, the light reflected from the mask is re-reflected to irradiate the mask, thereby increasing the illuminance on the irradiation surface of the mask. However, such a device has a drawback that illuminance unevenness is likely to occur on the mask because the light reflected from the mask whose reflectivity is not uniform on the surface is reused. The processing efficiency of the laser processing apparatus is limited by the minimum illuminance of the irradiation surface of the mask. Therefore, in order to achieve predetermined processing, the intensity of the laser beam must be increased in order to increase the minimum illuminance on the mask. as a result,
There is a problem that wasteful energy is consumed and the running cost of the laser processing apparatus is increased.

Further, in the conventional laser processing apparatus, even if the mask has fine holes opened at predetermined intervals, in order to improve the processing efficiency, it is necessary to irradiate the entire surface of the mask with a laser beam of a large energy. In addition, there is a disadvantage that wasteful energy is consumed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a laser processing method and apparatus for converging a laser beam to a plurality of locations, increasing energy, and performing predetermined processing on a workpiece. The purpose is to provide.

[0007]

According to the present invention, there is provided a laser processing method according to the first aspect of the present invention, comprising the steps of: generating a plurality of laser light fluxes; Irradiating a mask having a portion to generate interference fringes; matching the opening with a bright portion of the interference fringes; projecting a laser beam passing through the opening onto a workpiece; Processing the workpiece into a shape corresponding to the opening.

According to the present invention, the laser light is divided into two light beams, interference fringes are generated on the mask, and the bright portions of the interference fringes are made to coincide with the openings of the mask, so that the illuminance of the openings of the mask is increased. Is increased, and a laser beam having an intensity sufficient to process the workpiece is obtained.

According to a second aspect of the present invention, in the laser processing method according to the first aspect, the step of generating the plurality of laser beams is performed at a position conjugate with the mask or at a position near the mask. Generating a laser beam in two predetermined directions, wherein the step of generating the interference fringes includes a predetermined surface crossing a position conjugate with the mask or a position in the vicinity of the mask where the laser light is generated in the two predetermined directions. To
Projecting the interference fringes by projecting the mask with the first predetermined projection magnification onto the mask having the opening; and the step of processing the workpiece includes: The method is characterized in that the work is projected on the work at a predetermined magnification to process the work.

According to the present invention, a laser beam is divided into two light beams and emitted from a predetermined surface which crosses a position conjugate to a surface on which the opening pattern of the mask is formed or a position in the vicinity thereof, and the laser light is projected onto the mask surface at a predetermined magnification. By projecting, this 2
Generates interference fringes due to luminous flux interference, aligns the bright portions of the interference fringes due to the condensing of the laser light with the openings in the mask, increases the illuminance of the laser light, and is sufficient to process the workpiece. A laser beam with a high intensity is obtained.

According to a third aspect of the present invention, in the laser processing method according to the second aspect, the step of matching the bright portions of the interference fringes includes the step of adjusting the first predetermined magnification. It is characterized by.

According to the present invention, by projecting the laser beam onto the mask surface at a predetermined magnification and generating interference fringes due to the two-beam interference between the laser beams, the bright portion of the interference fringe and the opening can be easily matched. obtain.

According to a fourth aspect of the present invention, there is provided a laser processing apparatus which irradiates a mask having a predetermined opening with a laser beam supplied from a laser light source, so that the workpiece has a shape corresponding to the opening of the mask. An interference fringe generation system disposed between the laser light source and the mask to generate interference fringes on the mask, and an image of an opening of the mask for processing the workpiece. And a projection optical system for projecting the interference fringes, wherein the interference fringe generation system is configured such that a bright portion of the interference fringes coincides with an opening of the mask.

According to the present invention, the interference fringe generation system divides the laser beam into two light beams, and irradiates the two light beams onto the mask so as to generate interference fringes on the mask. The bright portion of this interference fringe is made to coincide with the opening pattern of the mask. Then, the image of the opening is projected onto the workpiece by the projection optical system. By condensing the laser light by such a two-beam interference effect, the illuminance of the laser light passing through the opening is increased to effectively obtain a laser light having sufficient intensity for processing the workpiece. Can be.

According to a fifth aspect of the present invention, in the laser processing apparatus according to the fourth aspect, the interference fringe generation system includes:
A light dividing member for dividing the laser light into a plurality of parts and an illumination optical system for guiding the plurality of divided laser lights onto the mask are provided.

According to the present invention, since the light splitting member splits the laser beam into a plurality of light beams, and these are guided by the illumination optical system onto the mask, interference fringes are generated by interference of these light beams.

According to a sixth aspect of the present invention, in the laser processing apparatus according to the fifth aspect, the light splitting member is arranged at a position conjugate to the mask or at a position near the mask, and is incident substantially perpendicularly. It is characterized by having a phase type pattern plate for converting laser light into diffracted light generated in two predetermined directions.

According to the present invention, the phase pattern plate converts the laser light into diffracted light in two directions, and the diffraction light generates interference fringes on the mask.

According to a seventh aspect of the present invention, in the laser processing apparatus according to the fifth or sixth aspect, the illumination optical system receives a plurality of laser beams split by the light splitting member and a plurality of light sources. , And a condenser optical system that collects light from the plurality of light sources and illuminates the mask in a superimposed manner.

According to the present invention, since the optical integrator forms a plurality of light sources and illuminates the mask in a superimposed manner, the illuminance on the mask can be made uniform, and the light is condensed as a plurality of light source images using the optical integrator. This makes it possible to easily equalize the illuminance for each of the opening patterns on the mask, to make the opening angle of the illumination light on the mask relatively large, and to make the pattern of the mask projected on the workpiece. Irregularities such as ringing hardly occur in the image intensity distribution of the image, and the workpiece can be processed more efficiently.

In the laser processing apparatus according to the present invention, the switching mechanism for exchanging the interference fringe generation system according to the shape of the opening of the mask is provided. It is further characterized by having.

According to the present invention, when the processing shape of the workpiece or the pitch of the holes formed in the workpiece is changed, the mask is changed to change the size and shape of the opening of the mask and the distribution of the opening pattern. However, since an appropriate phase pattern plate can be selected and replaced from a plurality of phase pattern plates at the same time, the laser beam can be focused on a position corresponding to the opening pattern of the mask.

According to a ninth aspect of the present invention, in the laser processing apparatus according to the fourth aspect, the interference fringe generation system includes:
A beam splitter that divides the laser light into two lights traveling in two different directions, and guides the divided light in one direction to the mask; and a beam splitter that is split by the beam splitter. And a reflecting member arranged to reflect the light to the mask.

According to the present invention, the laser beam is generated by the beam splitter into two light beams traveling in two directions, and the two light beams are guided to the mask and caused to interfere with each other. Forming a light-collecting part,
Used for laser light processing.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a laser processing method and apparatus according to the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a schematic view of an embodiment of a laser processing apparatus according to the present invention.

The main structure of the laser processing apparatus shown in FIG. 1 is a laser light source 1, a phase pattern plate 2, an illumination optical system 3, and a mask (a reticle having an opening pattern for processing a workpiece. 4), and a projection optical system 5 are arranged in this order, and a workpiece 6 is placed in front of the projection optical system 5. The phase pattern plate 2 and the mask 4 are The mask 4 and the workpiece 6 are
In the projection optical system 5, they are arranged at conjugate positions.

The phase pattern plate 2 is a transmission type phase grating plate which receives a laser beam L0 of a parallel light beam substantially perpendicularly, gives a phase difference of 1/2 wavelength of the laser beam L0, and emits ± 1st-order diffracted light. It is. The laser beam L0 is applied to the phase pattern plate 2
Are divided into + 1st-order diffracted light L1 and -1st-order diffracted light L2, and these ± 1st-order diffracted lights L1 and L2 are irradiated onto the mask 4 by the illumination optical system 3 at a predetermined magnification β, and interference fringes due to two-beam interference are formed. Generated on the mask 4. However, the magnification β of the illumination optical system 3 may be 1 in some cases.

The mask 4 has openings 4a formed at a predetermined pitch, and the bright portion A1 of the light / dark line A is formed in the opening 4a of the mask 4.
The mask 4 is arranged so as to coincide with. Note that A
2 indicates a dark area.

The projection optical system 5 projects the opening pattern of the mask 4 at a predetermined reduction magnification, thereby forming a workpiece 6.
Laser light is focused on the surface in accordance with the opening pattern, and continuous fine holes having a diameter of, for example, about 50 microns can be opened in the workpiece 6. In this laser processing apparatus, energy of 1 to 100 J / cm ² is generated.

Next, a laser processing method will be described with reference to FIG. A laser beam L0 such as an excimer laser beam is emitted from a laser light source 1, and a laser beam L0 of a parallel light beam is irradiated on the phase pattern plate 2 vertically. In the phase pattern plate 2, a one-dimensional phase pattern in which a phase difference of a half wavelength of the laser light L0 having a wavelength λ repeats at a predetermined pitch P is applied to a parallel flat plate made of glass or the like. When the laser beam L0 is perpendicularly incident on the phase pattern plate 2, the laser beam having a phase difference of 1/2 wavelength becomes almost ± 1st order diffracted light L1, L
The light is emitted as 2 and enters the illumination optical system 3. Then, the diffracted lights L1 and L2 are projected via the illumination optical system 3 onto the mask 4 arranged at a position conjugate with the phase pattern plate 2 at a predetermined magnification β. On the mask 4, interference fringes due to two-beam interference of the ± 1st-order diffracted lights L 1 and L 2 are generated as shown by a light-dark line A. The pitch of the interference fringes is βP / 2.

Openings 4a are formed at a predetermined pitch in the mask 4, and the length of the openings 4a is set to βP / 4 or less along the periodic direction of the interference fringes. With this setting, by adjusting the position of the phase pattern plate 2 in a plane perpendicular to the optical axis, the bright portion A1 of the interference fringe on the mask 4 matches the opening 4a of the mask 4. Can be. The illuminance of the laser light projected onto the opening 4a is increased about twice, and the opening pattern 4a of the mask 4 is projected onto the workpiece 6 by the projection optical system 5 at a predetermined magnification.
For example, when the opening 4a is a point-like opening, a minute hole can be opened in the workpiece 6.

That is, in the present embodiment, in the step of generating interference fringes, the surface on which the laser beams as the ± 1st-order diffracted lights L1 and L2 are generated in two predetermined directions is conjugate with the mask or the mask. A predetermined surface crossing a position near a position conjugate with the above is projected onto the mask 4 having the opening 4a at a predetermined projection magnification β by an illumination optical system to generate interference fringes. The predetermined projection magnification β includes 1.

Further, the step of processing the workpiece is a step of reducing and projecting the laser beam passing through the opening 4a of the mask 4 onto the workpiece 6 at a predetermined magnification to process the workpiece 6. is there.

The light from the aperture pattern is condensed by the projection optical system 5 and the aperture pattern image is transferred onto the workpiece 5 to form fine holes in the workpiece 5 at a predetermined pitch. Can be formed. Since the laser light is focused on the workpiece 5 and the laser light amount per unit area increases, a large energy density can be generated.

FIG. 2 shows an embodiment of the phase pattern plate 2, wherein FIG. 2 (a) is a plan view and FIG. 2 (b) is a cross-sectional view taken along the line XY. is there. The phase pattern plate 2 in FIG. 2 is a phase type pattern plate on which a pattern having a checkered convex portion 2a is formed. In FIG. 3A, the shaded portion indicates a concave portion, and the white portion 2a indicates a convex portion. Using the phase pattern plate 2, the generation of interference fringes is made two-dimensional, and the illuminance on the workpiece surface can be increased about four times by the same two-beam interference effect as described above. With this method, the time for laser processing can be further reduced.

In this embodiment, the phase pattern plate 2
An exchange mechanism that can exchange the phase pattern plate 2 may be provided adjacent to. This exchange mechanism accommodates several types of phase pattern plates, and is, for example, a turret mechanism that selects and replaces a desired phase pattern plate according to the opening pattern of the workpiece. This turret mechanism automatically selects the phase pattern plate according to the size and shape of the opening of the mask and the distribution of the opening on the mask when changing the processing shape and the distribution of the opening of the workpiece. Can be replaced. Since it is possible to match the diameter of the processing hole of the workpiece and the pitch of the processing hole, the processing capacity is improved, and the illuminance of the mask can always be set high, so that the processing performance can be maintained. Needless to say, the exchange mechanism may have a structure that can be easily replaced by a manual operation when the phase pattern plate 2 hardly needs to be replaced.

(Embodiment 2) FIG. 3 is a view showing another embodiment of the laser processing apparatus according to the present invention.

FIG. 3 is different from the embodiment of FIG. 1 in that an optical integrator 9 and a condenser lens 10 are used as an illumination optical system between the phase pattern plate 8 and the mask 11.
And a laser processing apparatus provided with the above. As shown in the cross-sectional view of FIG. 4, the phase pattern plate 8 is formed with a plurality of phase patterns 8a in which a phase difference of a half wavelength of the incident laser light repeats at a predetermined pitch P.

A laser beam L0 of a parallel light beam emitted from a laser light source 1 such as an excimer laser is adjusted to an appropriate light beam shape by a beam shaping optical system 7 such as a cylindrical lens.
Irradiation is performed almost perpendicularly to the pattern surface of the phase pattern plate 8 disposed at a position conjugate with the mask 11. The ± 1st-order diffracted lights L1 and L2 emitted from the phase pattern plate 8 are projected onto the mask 11 at a magnification β via an optical integrator 9 and a condenser lens 10. The ± 1st-order diffracted lights L1 and L2 emitted from the phase pattern 8a arranged on the light-source-side focal plane of the optical integrator 9 are formed after the respective focal points F1 and F2 are formed on the mask-side focal plane of the optical integrator 9. Is further condensed by the condenser lens 10. Each of the converging points F1 and F2 illuminates the mask 11 with Koehler illumination at mutually different incident angles. By illuminating the mask 11 in this manner, interference fringes are generated on the mask 11 at a pitch of βP / 2, as indicated by the light and dark lines A.

As in the first embodiment, if the length of the opening pattern formed on the mask 11 is set to βP / 4 or less along the periodic direction of the interference fringes, the phase pattern plate 8 is By adjusting the position in a vertical plane, the bright portion of the interference fringe can be matched with the opening pattern on the mask. In this way, the illuminance on the opening pattern surface can be approximately doubled. If the phase pattern is made two-dimensional, the illuminance is increased about four times by the same two-beam interference effect as described above. Light from the opening pattern of the mask 11 is condensed by the projection optical system 12, an opening pattern image is formed on the work 13, and processing according to the opening pattern can be performed on the work 13.

Also, by using the optical integrator 9, the illuminance of each opening pattern on the mask 11 can be easily made uniform, and the opening angle of the illumination light on the mask 11 can be made relatively large. Thus, unevenness such as ringing does not easily occur in the image intensity distribution of the pattern image of the mask projected on the workpiece 13, and the workpiece can be processed more efficiently.

As in the first embodiment, a turret mechanism containing a plurality of phase patterns is provided in the vicinity of the phase pattern plate 8 so as to change the processing shape and distribution on the workpiece when using a mask. 11 is changed to change the size and shape of the opening pattern of the mask and the distribution of the opening pattern on the mask, and by replacing the phase pattern plate 8 with an appropriate one according to the opening pattern of the mask, the illuminance of the mask is always changed. Can be kept high.

(Embodiment 3) FIG. 5 shows another embodiment of the laser processing apparatus according to the present invention.

In FIG. 2, a laser beam L 0 emitted from a laser light source 1 is incident on a beam splitter 14.
The laser beam incident on the beam splitter 14 is split into two laser beams L4 and L5 traveling in two different directions. The divided one-way laser light L4 is applied to the mask 16
The other laser beam L5 is reflected by the reflection mirror 15, and the reflected light L6 is guided to the mask 16. By irradiating the mask with two luminous fluxes of the laser beams L4 and L6 obtained by the division from two directions, an interference fringe is generated on the irradiation surface of the mask 16, and the bright portion coincides with the opening of the mask 16. Let it. This is a laser processing apparatus capable of reducing and projecting a spot-shaped laser beam that has passed through a mask 16 onto a workpiece 18 by a projection optical system 17 to form, for example, a fine hole in the workpiece 18.

The method of matching the bright portion of the interference fringes with the opening of the mask 16 is such that the beam splitter 14 and the reflection mirror 15 are moved in the optical axis direction, and the surface of the reflection mirror 15 is tilted. It can be adjusted to the opening pattern.

In this case, the laser light L4 divided into two
In order for L5 and L5 to generate interference fringes on the mask 16,
It is preferable to make the directions on a plane intersecting the traveling direction of the laser light coincide. In particular, this is important for laser light having a short wavelength such as an excimer laser. For that purpose, the laser light L
The number of reflections of 4 and L5 may be the same, or the number of reflections of both may be shifted by an even number.

The position of the reflection mirror 15 and the mask 16 may be changed so that the laser beam L5 is guided to the mask 16, and the laser beam L4 is reflected by the reflection mirror 15 and guided to the mask. It is clear that the projection optics 17
Is changed in accordance with the mask 16.

Further, in the first and second embodiments, the lens of the illumination optical system and the condenser lens have a zoom configuration, and the projection magnification of the phase pattern is selected in accordance with the aperture pattern of the mask, so that the bright portion of the interference fringe and the aperture are selected. Obviously, the pattern may be matched.

In the first and second embodiments,
The example in which the phase pattern plates 2 and 8 are used as the diffraction optical members for diffracting the laser light L0 to generate diffracted light in two predetermined directions has been described. However, the present invention is not limited to this. For example, the phase pattern plates 2 and 8 are used. Instead of acousto-optic modulator (AOM)
Can be used. This acousto-optic modulator has an acousto-optic medium made of optical glass, quartz, quartz, a single crystal of tellurium dioxide (TeO ₂ ) or a single crystal of lead molybdate, and a transducer provided at one end thereof. It is.

In this case, when a drive signal from a drive unit (not shown) is input to the transducer in the acousto-optic modulation element, an ultrasonic wave is applied to the acousto-optic medium, and the medium has a predetermined pitch. Is generated. That is, the density of the predetermined pitch constantly exists in the medium. Since the standing wave substantially functions as a diffraction grating, the acousto-optic modulator can have substantially the same function as the phase pattern plates 2 and 8.

Furthermore, when the output or frequency of the drive signal input to the transducer in the acousto-optic modulator is changed by a drive device (not shown), the pitch of the standing wave generated in the acousto-optic medium is changed. Can be. For this reason, even when using the masks 4 and 11 having different sizes and shapes of the openings 4a and 11a in the workpieces 6 and 13 in accordance with the pitch of the processing holes, the sizes and shapes of the openings 4a and 11a are different. According to the change of the masks 4 and 11,
The output or frequency of the drive signal input to the transducer in the acousto-optic modulator may be changed by a drive device (not shown).

In the third embodiment, two light beams L4
The pitch of the interference fringes can be changed by changing the angles of incidence of L6 and L6 on the mask, so that the bright portion of the interference fringes and the aperture pattern can be matched.

[0054]

As described above, according to the present invention, the interference fringes due to the two-beam interference of the laser light are generated on the mask, and the bright portions thereof are made to coincide with the openings of the mask, whereby the workpiece is processed. It is possible to increase the illuminance of the laser light applied to the object, and there is an advantage that the efficiency of laser processing can be improved.

Further, a phase pattern plate is provided on a plane traversing a position conjugate with the mask or in the vicinity thereof, and the phase pattern plate is emitted as a pattern in which the phase difference of a half wavelength of the incident laser light is repeated. There is an advantage that it is possible to provide a laser processing apparatus that can increase energy by forming light by interference of two light beams of laser light to form fine holes at predetermined intervals in a workpiece.

Further, the phase pattern plate is set to a phase pattern of 2
By increasing the dimension, the illuminance can be increased to four times, so that there is an advantage that the processing efficiency of the laser processing apparatus can be further improved.

Further, by providing the illumination optical system with an optical integrator and a condensing optical system for condensing the laser light emitted from the optical integrator and irradiating the mask with the optical integrator, the uneven light amount distribution can be made substantially uniform. There is an advantage that it is possible to provide a laser processing apparatus capable of forming holes having the same shape as a workpiece at predetermined intervals.

Further, by providing a switching mechanism for exchanging the phase pattern according to the opening pattern of the mask,
There is an advantage that it is possible to provide a laser processing apparatus that can adjust the energy of the opening pattern of the mask and the workpiece to the best state and process the workpiece.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a first embodiment according to the present invention.

FIG. 2 is a diagram showing an outline of a two-dimensional phase pattern plate arranged in a checkered pattern, (a) is a plan view thereof, and (b)
FIG. 3 is a cross-sectional view taken along line XY of FIG.

FIG. 3 is a diagram showing a schematic configuration when a second embodiment of the present invention, that is, an optical integrator is used.

FIG. 4 is a cross-sectional view of a phase pattern plate used in the embodiment of FIG.

FIG. 5 is a diagram showing a schematic configuration of a third embodiment according to the present invention, that is, a case where a beam splitter is used.

FIG. 6 is a view showing a conventional laser processing apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 laser light source 2 phase pattern plate 3 illumination optical system 4, 11 mask 4 a opening 5 projection optical system 6 workpiece 7 beam shaping optical system 8 phase pattern plate 8 a phase pattern 9 optical integrator 10 condenser lens 11 mask 11 a opening 12 Projection optical system 13 Workpiece 14 Beam splitter 15 Reflection mirror 16 Mask 17 Projection optical system 18 Workpiece

Claims (9)

[Claims] Generating a plurality of laser beams;
Irradiating the plurality of laser beams onto a mask having an opening to generate interference fringes; aligning the openings with the bright portions of the interference fringes; Projecting the workpiece onto the workpiece and processing the workpiece into a shape corresponding to the opening. 2. The step of generating a plurality of laser beams includes a step of generating laser beams in two predetermined directions at a position conjugate to the mask or at a position near the mask; and a step of generating the interference fringes. Projecting a predetermined plane crossing a position conjugate to the mask or a position near the conjugate where the laser light is generated in two predetermined directions onto a mask having the opening at a first predetermined projection magnification to cause interference. The step of processing the workpiece includes projecting the laser beam that has passed through the opening onto the workpiece at a second predetermined magnification to process the workpiece. The method according to claim 1, further comprising a step. 3. The step of matching bright portions of the interference fringes,
The laser processing method according to claim 2, further comprising a step of adjusting the first predetermined magnification. 4. A laser processing apparatus for processing a workpiece to a shape corresponding to an opening of a mask by irradiating a mask having a predetermined opening with laser light supplied from a laser light source; An interference fringe generation system disposed between the laser light source and the mask to generate interference fringes on the mask; and a projection optical system for projecting an image of the opening of the mask onto the workpiece; The laser processing apparatus according to claim 1, wherein the interference fringe generation system is configured so that a bright portion of the interference fringe coincides with an opening of the mask. 5. The interference fringe generation system includes a light splitting member that splits the laser light into a plurality, and an illumination optical system that guides the split plurality of laser lights onto the mask. The laser processing device according to claim 4. 6. The phase splitting member, which is disposed at a position conjugate with the mask or at a position near the mask and converts a substantially perpendicularly incident laser beam into diffracted light generated in two predetermined directions. The laser processing apparatus according to claim 5, further comprising a pattern plate. 7. An illumination optical system, comprising: an optical integrator for receiving a plurality of laser beams split by the light splitting member to form a plurality of light sources; and condensing light from the plurality of light sources. The laser processing apparatus according to claim 5, further comprising a condenser optical system that illuminates the mask in a superimposed manner. 8. The laser processing apparatus according to claim 4, further comprising a switching mechanism for exchanging the interference fringe generation system according to the shape of the opening of the mask. . 9. The interference fringe generation system divides the laser light into two lights traveling in two different directions and arranges the divided light in one direction to the mask. The laser processing apparatus according to claim 4, further comprising: a splitter; and a reflecting member arranged to reflect the light in the other direction split by the beam splitter and guide the light to the mask.