JP2003275889A - Laser beam machining apparatus and method for working thin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser beam machining apparatus and laser beam machining method with an improved working accuracy which can form a groove with a uniform width or a groove narrower than the diameter of an irradiation spot of a laser beam on a workpiece to be worked by the laser beam, and does not leave a residual material in the vicinity of the workpiece. <P>SOLUTION: The laser beam machining apparatus includes a laser beam source 1 and a scanning means which makes a laser beam 2 emitted from the laser beam source 1 scan a workpiece 4 to work the workpiece 4 with the laser beam 2. The apparatus further includes a workpiece cooling means 51 having a groove 11 of the same shape as the pattern worked on the workpiece 4. A second laser beam source which radiates a second laser beam onto a worked groove formed after an irradiation with the laser beam is provided. The residual material remaining around the worked groove after the irradiation with a first laser beam can be eliminated by the irradiation with the second laser beam from the second laser beam source. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to processing of thin film materials formed on industrial products such as electronic parts such as ICs, glass substrates of liquid crystals or PDPs.

[0002]

2. Description of the Related Art Conventionally, a laser processing apparatus has been constructed as shown in FIG. In the laser processing apparatus shown in FIG. 16, 1 is a laser light source, 2 is a laser beam emitted from the laser light source 1, 31 is a galvano scanner for scanning the laser beam 2, and 32 is an optical lens. Reference numeral 4 denotes a work piece in which the thin film 41 is formed on the glass substrate 42. Reference numeral 5 is a support base that supports the workpiece 4.

The operation will be described. The laser light 2 emitted from the laser light source 1 is passed through the optical lens 32 to the thin film 41.
Focused on top. The thin film 41 in the irradiated portion is physically changed by the laser light 2, for example, melting, vaporization, disappearance, foaming,
It is removed by causing bumps, discoloration, decolorization, etc. In this state, the galvano scanner 31 scans the irradiation position of the laser beam 2 to form the processed groove 10 in the thin film 41.

Further, in the laser processing apparatus shown in FIG. 17, 1 is a laser light source, 2 is laser light emitted from the laser light source 1, 3 is a focusing means, 4 is a workpiece, and a thin film 41 is formed on a substrate 42. Has been formed. Reference numeral 52 is a scanning unit including an XY stage and the like.

The laser light 2 emitted from the laser light source 1 is
The light collecting means 3 collects light on the thin film 41 in the form of a workpiece. The laser beam 2 causes the thin film 41 to undergo a physical change, for example, peeling, melting, vaporization, disappearance, foaming, protrusion, discoloration, decolorization or the like of the surface or surface layer. In this state, the scanning means 52 scans the focus position of the laser light 2 to form the processed groove 10 in the thin film 41.

Particularly, the case where the thin film 41 is a diamond-like carbon film will be described below. The diamond-like carbon film has wear resistance, a flat surface can be obtained,
Because of its small static friction coefficient and dynamic friction coefficient with various metals, it has been attracting attention as a coating film for protecting various materials and preventing friction. Also, since it is chemically inert, it allows the use of jigs and tools in an atmosphere where metals are usually decomposed. Further, although it is known that good insulating properties can be obtained, in recent years, attempts have been made to impart conductivity thereto.

By the way, in these application fields, it may be necessary to remove the formed diamond-like carbon film. For example, in the case of positioning or positioning on mechanical parts such as jigs or tools, or providing a marker for identifying members, or forming a circuit or the like utilizing the insulating or conductive properties of the diamond-like carbon film, It is necessary to process it into a predetermined pattern. Therefore, as a conventional apparatus for processing a diamond-like carbon thin film, Japanese Patent Application Laid-Open No. 11-2789.
There was the device of the '90 publication. In this device, a laser light source having a wavelength of 10 μm or less is used.

[0008]

However, when the conventional laser processing apparatus is used, the heat generated in the workpiece by the laser light spreads to the periphery of the irradiation portion, and the periphery of the irradiation portion also undergoes a physical change and is formed. The processed groove may be larger than the laser irradiation spot diameter. Therefore, the problem that the pattern formed on the workpiece cannot be miniaturized, the width of the machining groove is the laser output, the material of the workpiece,
There is a problem in that it is difficult to form a processed groove with a uniform width due to the influence of thickness, ambient temperature and the like.

Further, even if the heat generated in the workpiece by the laser light does not spread to the periphery of the irradiation portion, it is impossible to form a processing groove having a width smaller than the laser irradiation spot diameter.
There was a problem in processing accuracy.

Further, when a galvano-type scanner is used as the laser beam scanning means, due to the aberration of the optical system, as shown in FIG. 18, the irradiation spot diameter 92 at the peripheral portion is larger than the irradiation spot diameter 92 at the peripheral portion of the scanning area. , 93 becomes large. Therefore, there is a problem in processing accuracy that the width of the processing groove in the peripheral portion becomes wider than that in the central portion of the scanning area.

Further, if the conventional technique is to be used,
Actually, after the laser irradiation, a residue is generated in which the thin film is not completely removed. In particular, melting of the thin film layer by laser light,
When a physical change such as vaporization occurs in the thin film, there is a problem in processing accuracy that the melt reattaches to the vicinity of the groove and becomes a residue. These residues were a cause of deterioration in quality of the diamond-like carbon film after patterning, such as poor insulation in patterning the diamond-like carbon film having conductivity and light scattering for optical applications. .

Therefore, according to the present invention, it is possible to form a groove having a uniform width or a groove smaller than the irradiation spot diameter of the laser beam on the workpiece to be laser-processed, and the processing accuracy does not leave a residue in the vicinity of the processed portion. A laser processing apparatus and a laser processing method that improve

[0013]

In order to solve the above problems, a first laser processing apparatus includes a laser light source, a scanning means for scanning the laser light emitted from the laser light source, and a support for mounting a workpiece. In the laser processing apparatus for processing the workpiece with the laser beam, the support table includes workpiece cooling means having a groove having the same shape as the pattern to be processed on the workpiece. .

With the above structure, the heat spread around the laser irradiation portion can be cooled by the workpiece cooling means, so that the processed groove can be formed with a uniform width according to the width of the groove portion of the workpiece cooling means. .

In order to solve the above problem, the second laser processing apparatus is such that the width of the groove portion of the workpiece cooling means is smaller than the irradiation spot diameter of the laser beam focused on the workpiece. is there.

With the above structure, a processed groove having a width smaller than the laser irradiation spot diameter can be formed. Further, since the width of the processed groove formed on the workpiece is determined by the width of the groove portion of the workpiece cooling means, even if a galvano scanner is used as the scanning means of the laser light, a uniform width is obtained over the entire scanning area. A processed groove can be formed with.

In a third laser processing apparatus for solving the above problem, the object to be processed is a thin film formed on a glass substrate, and the thin film is irradiated with the laser light from the glass substrate side.

With the above structure, when the laser beam is irradiated, the workpiece cooling means can be brought into contact with the thin film side to cool the portion which is not desired to be processed.

In the processing apparatus of the fourth invention, in the third invention, the thin film is a diamond-like carbon film.

In order to solve the above problems, the thin film processing apparatus of the fifth invention is the first thin film processing apparatus which irradiates the first laser beam on the thin film.
In the thin film processing apparatus, the thin film processing apparatus comprises a laser light source and a scanning means for scanning the thin film with the laser light.
And a second laser light source for irradiating the processed groove formed after the laser light irradiation with the second laser light.

In a sixth aspect based on the fifth aspect, the thin film is a diamond-like carbon film.

In order to solve the above problems, a thin film processing method of a seventh invention is the thin film processing method of irradiating a laser beam on the thin film to remove a part of the thin film, which is formed after the laser beam irradiation. The method includes a step of repeatedly irradiating the processed groove with laser light.

According to the processing method of the eighth invention, in the seventh invention, the thin film is a diamond-like carbon film,
It is possible to solve the above problem that occurs in the case of a diamond-like carbon film.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The cooling means for a workpiece used in the present invention may be constituted by a metal material having a low heat resistance such as aluminum, copper or iron which is patterned by machining or etching. it can.

[0025]

First Embodiment A thin film processing apparatus according to the first embodiment of the present invention will be described with reference to FIG. In FIG. 1, 1 is a laser light source, 2 is laser light emitted from the laser light source 1, 31 is a galvano-type scanner which is a scanning means for scanning the laser light 2, 32 is a condenser lens which is a condenser means, 4 is a Work piece with glass substrate 4
A thin film 41 is formed on the surface 2. Reference numeral 51 denotes an object cooling means, which has a groove portion 11 having the same shape as the pattern to be processed on the thin film 41 and having the same width as the irradiation spot diameter of the laser beam 2 as shown in FIG. As shown in FIG. 1, the workpiece 4
However, when the thin film 41 is formed on the glass substrate 42, the workpiece cooling means 51 can be brought into contact with the thin film 41 side by installing the thin film 41 so that the glass substrate side irradiates the laser beam.

As the laser light source 1, a gas laser such as a semiconductor laser, a carbon dioxide gas laser, a He-Cd laser, an Ar laser, or an excimer laser, a YAG laser, a YV is used.
A harmonic laser light source that emits a laser beam having a wavelength of a harmonic component can be used by combining with a solid laser such as O4, YLF laser, glass laser, and fiber laser, liquid laser such as dye laser, and nonlinear optical crystal. The laser light 2 may be guided by an optical fiber or the like. Although an XY stage can be used as the scanning means, it is preferable to use a galvano scanner in terms of scanning speed. The workpiece 4 can also be applied to the workpiece 4 without a glass substrate. However, in order to cool the heat generated in the workpiece 4 by the irradiation of the laser beam 2 by the workpiece cooling means 51 as described below, the effect of the present invention can be expected in a thin workpiece. Therefore, a thin film formed on a glass substrate, which is particularly effective, will be described as an example.

The operation will be described. The laser light 2 emitted from the laser light source 1 is condensed by the condenser lens 32 on the thin film 41 in the form of a workpiece. The thin film 41 undergoes a physical change (melting, vaporization, disappearance) by the laser light 2. In this state, the galvano scanner 31 scans the focus position of the laser light 2 to form the processed groove 10 in the thin film 41.

The process of forming the processed groove 10 will be described with reference to the drawings. 3 shows a conventional laser processing apparatus, and FIG. 4 shows a process of forming the processing groove 10 in the apparatus of this embodiment.
When a conventional laser processing device is used, heat 81 generated in the workpiece by the laser beam 2 spreads as diffusion heat 82 to the periphery of the irradiation portion as shown in FIG. 3 depending on the type of the workpiece. The diffusion heat 82 may cause a physical change in the periphery of the irradiation portion, and the processed groove 10 formed may be larger than the irradiation spot diameter of the laser beam 2. On the other hand, when the apparatus of the present embodiment is used, the diffusion heat 82 spread to the periphery of the laser irradiation portion as shown in FIG. 4 flows into the workpiece cooling means 51, the thin film 41 around the laser irradiation portion is cooled, and physical change occurs. Does not reach the temperature that causes Therefore, when the apparatus of this embodiment is used, the processed groove 10 formed on the thin film 41 does not become larger than the irradiation spot diameter of the laser beam 2.

Using a semiconductor laser as the laser light source 1, a diamond carbon thin film formed on a glass substrate was subjected to a processing test. The condensing means was configured so that the laser irradiation spot diameter was 50 μm. A groove having a width of 50 μm was formed in the workpiece cooling means. When a test was performed with a conventional configuration without using the workpiece cooling means 51, the width of the processed groove varied from 50 to 65 μm.
Next, when a test was performed using the workpiece cooling means 51, it was possible to form a processed groove with a uniform width of 50 to 52 μm.

Second Embodiment A thin film processing apparatus according to the second embodiment of the present invention will be described. Second
The apparatus of this embodiment is different from that of the first embodiment in that the width of the groove 11 of the workpiece cooling means 51 is smaller than the converging diameter of the laser. The process of forming the processed groove 10 on the thin film 41 in the second embodiment will be described with reference to the drawings. Figure 5
Is a conventional laser processing apparatus, and FIG. 6 is a process of forming the processing groove 10 in the apparatus of this embodiment. With conventional devices,
As shown in FIG. 5, heat 81 generated in the thin film by the laser beam 2
However, there is a problem that a processed groove smaller than the laser irradiation spot diameter cannot be formed even in a workpiece that does not spread to a thin film other than the laser irradiation portion. On the other hand, when the apparatus according to the present embodiment is used, the heat generated in the laser irradiation part 8 as shown in FIG.
Heat of part 1 of the part 1 in contact with the workpiece cooling means 51
Flows into the workpiece cooling means 51, and the thin film in that portion does not reach the temperature at which physical change occurs. Therefore, a processed groove having a width smaller than the laser irradiation spot diameter can be formed.

Utilizing this, the workpiece cooling means 5
When the groove 11 of No. 1 is set smaller than the irradiation spot diameter in the center of the scanning area, the irradiation spot diameter is not affected by the nonuniformity as shown in FIG. The processed groove 10 can be formed in the workpiece 4.

Using a semiconductor laser as the laser light source 1, a processing test was conducted on a diamond-like carbon thin film formed on a glass substrate. The condensing means was configured so that the laser irradiation spot diameter was 50 μm. A pattern as shown in FIG. 7 having a groove portion having a width of 30 μm was formed on the workpiece cooling means. When a test was performed with a conventional configuration without using the workpiece cooling means 51, the width of the processed groove was 50 μm in the center of the area and 55 μm in the peripheral area. Next, when a test was performed using the workpiece cooling means 51, it was possible to form a machined groove with a uniform width of 30 μm over the entire area.

Third Embodiment A laser marking apparatus according to the first embodiment of the present invention will be described with reference to FIG. In FIG. 8, 1 is a laser light source, 2
Is a laser beam emitted from the laser light source 1, 3 is a focusing means, 4 is a workpiece, and a thin film 41 is formed on a substrate 42. Reference numeral 5 is a scanning means including an XY stage and the like.
The second laser light 22 emitted from the second laser light source 21
Is the first laser light 2 emitted from the first laser light source 1.
The light is focused on the processed groove 10 processed by. The first laser light source 1 or the second laser light source 21 includes a semiconductor laser, a carbon dioxide gas laser, a He-Cd laser, an Ar laser, a gas laser such as an excimer laser, a YAG laser, a YVO4, a YLF laser, a glass laser, and a fiber. A solid-state laser such as a laser, a liquid laser such as a dye laser, or a harmonic laser light source that emits a laser beam having a wavelength of a harmonic component by combining with a nonlinear optical crystal can be used. In this embodiment, a semiconductor laser is used as the laser light source 1. By using a semiconductor laser, the structure is very simple and the device can be miniaturized. Further, the semiconductor laser has an extremely high efficiency as compared with other laser light sources, and has an advantage that the power consumption of the device can be reduced. The first laser light 2 or the second laser light 22 may be guided by an optical fiber or the like. In addition to the XY stage used in this embodiment as a scanning means, there is also a system in which a laser beam is scanned by a galvano scanner. In that case, it is preferable to arrange arbitrary optical components such as a collimator lens and a beam expander between the laser light source 1 and the scanner mirror.

Next, the operation will be described with reference to FIG.

(Step 201) When the thin film 41 is scanned while being irradiated with the first laser beam 2, the thin film 41 in the laser irradiation portion is melted and vaporized, whereby the processed groove 10 is processed.

Step 202) Processed groove 1 after laser irradiation
At 0, the melt 11 remains. Step 203) The melt 11 is cooled and solidified, and the residue 1
2 is attached to the substrate 42.

Step 204) When the machining groove 10 is irradiated with the second laser beam 22 and scanned, the residue 12 is melted and vaporized, so that the residue 12 is removed from the machining groove 10.

Preferably, before the melt solidifies, a second
It is advisable to bring the focal point of the second laser light 22 close to the focal point of the first laser light 2 so that the laser light is heated and vaporized. The operation in this case will be described with reference to FIG.

Step 301) When the thin film 41 is scanned while being irradiated with the first laser beam 2, the thin film 41 in the laser irradiation portion is melted and vaporized, so that the processed groove 10 is processed.

Step 302) Processed groove 1 after laser irradiation
At 0, the melt 11 remains.

Step 303) Before the melt 11 is cooled and solidified, the second laser beam 22 is irradiated and vaporized, so that the residue 12 does not adhere to the processed groove 10.

Even if the forming direction of the processed groove 10 is changed,
In order to obtain the above-described action, it is necessary to devise the arrangement so that the second laser beam 22 is always irradiated after the first laser beam 2 is irradiated. As a measure, a third laser light source 31 may be used as shown in FIG. 11, and a third laser light 32 may be used instead of the second laser light 22.
A rotary stage 51 is added as shown in FIG.
May be rotated. Alternatively, the first laser light source 1 and the second laser light source 21 may be rotated while leaving the workpiece 4 as it is. When a galvano-type scanner is used as the scanning means S, the second laser light is always emitted after the first laser light 2 is emitted.
It is possible to easily irradiate the laser beam 22 of 1. by controlling the scanner mirror.

The diamond-like carbon thin film formed on the glass substrate was actually tested using the processing apparatus shown in FIG. A semiconductor laser was used for each of the first laser light source 1 and the second laser light source 2, and light was guided to the condenser lenses 3 and 23 by an optical fiber. The focused diameters of the laser light 2 and the laser light 22 are both 50 μm. First,
In order to check the processing result in the conventional processing apparatus, processing was performed without using the second laser light 2 from the second laser light source 2. The output of the semiconductor laser of the first laser light source 1 was set to 1W. Scanning speed by stage is 4mm
/ Sec. The results are shown in Fig. 13. Although a groove having a width of 50 μm can be processed, it can be seen that many residues are attached.

Next, in order to adjust the processing result in the processing apparatus of the present invention, processing was performed using the second laser light from the second laser light source 2. The outputs of the semiconductor lasers of the first laser light source 1 and the second laser light source 21 were set to 1W. Further, the focusing position of the second laser light 22 was adjusted to be 150 μm behind the focusing position of the first laser light 2. The results are shown in Fig. 14. Grooves with a width of 50 μm have been machined and no residue is observed.

Fourth Embodiment A thin film processing method according to the fourth embodiment of the present invention will be described with reference to FIG. The difference from the process of FIG. 9 described in the first embodiment is that the machining groove 10 is irradiated again with the first laser light 2 from the first laser light source 1 instead of the second laser light. It is a point. As a device configuration, a conventional processing device can be used as shown in FIG. 17 without adding a second laser light source. As an irradiation method, it is possible to perform irradiation by repeating forward and backward movements as shown in the figure. Further, as shown in the figure, it is possible to move forward while irradiating several times at one place.

A processing test was conducted on a diamond-like carbon thin film formed on a silicon wafer by using the thin film processing method of this example. Second to second used in the third embodiment
The apparatus in which the laser light source 21 in FIG. After the second laser irradiation, a large amount of residue remained as compared with the case of using the processing apparatus of the third embodiment. When the test was conducted by increasing the number of laser irradiations, no residue was observed after the laser irradiation was performed 5 times.

In the above-mentioned embodiments, the embodiments of the diamond-like carbon thin film on the glass substrate or the diamond-like carbon thin film on the wafer substrate are shown, but in addition, the chromium film on the glass substrate and the color filter on the glass substrate. The processing apparatus and processing method of the present invention can be used for processing other thin films such as films.

[0048]

As described above, according to the laser processing apparatus of the present invention, the heat spread around the laser irradiation portion can be cooled by the workpiece cooling means, so that the groove portion of the workpiece cooling means can be cooled. The processed groove can be formed with a uniform width according to the width of the.

According to the laser processing apparatus of the present invention,
The width of the groove portion of the workpiece cooling means is smaller than the irradiation spot diameter of the laser beam focused on the workpiece, so that the processing groove has a width smaller than the laser irradiation spot diameter. Can be formed. Further, since the width of the processed groove formed on the workpiece is determined by the width of the groove portion of the workpiece cooling means, even if a galvano scanner is used as the scanning means of the laser light, a uniform width is obtained over the entire scanning area. A processed groove can be formed with.

Further, as described above, according to the thin film processing apparatus of the present invention, the residue remaining around the processing groove after the irradiation of the first laser light is used as the second laser light from the second laser light source. Since it can be erased by irradiation, it is possible to process a thin film that does not leave a residue in the vicinity of the processed groove.

According to the processing method of the present invention, the residue left around the processing groove after the first laser light irradiation can be eliminated by the second and subsequent laser light irradiation, so that no residue remains near the processing groove. The thin film can be processed using a conventional processing device.

[Brief description of drawings]

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

FIG. 2 is a schematic configuration diagram showing a workpiece cooling means according to the first embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing a process of forming a processing groove in a conventional laser processing apparatus.

FIG. 4 is a schematic configuration diagram showing a process of forming a processing groove in the laser processing apparatus according to the first embodiment of the present invention.

FIG. 5 is a schematic configuration diagram showing a process of forming a processing groove in a conventional laser processing apparatus.

FIG. 6 is a schematic configuration diagram showing a process of forming a processing groove in a laser processing apparatus according to a second embodiment of the present invention.

FIG. 7 is a schematic top view of the workpiece cooling means according to the second embodiment of the present invention.

FIG. 8 is a schematic configuration diagram showing a configuration of a thin film processing apparatus according to a third embodiment of the present invention.

FIG. 9 is a schematic diagram showing a processing operation of a third embodiment of the present invention.

FIG. 10 is a schematic diagram showing another machining operation of the third embodiment of the present invention.

FIG. 11 is a schematic configuration diagram showing a configuration of a thin film processing apparatus according to a third embodiment of the present invention.

FIG. 12 is a schematic configuration diagram showing a configuration of a thin film processing apparatus according to a third embodiment of the present invention.

FIG. 13 is a photograph showing processing results in a conventional thin film processing apparatus.

FIG. 14 is a photograph showing the processing result of the third embodiment of the present invention.

FIG. 15 is a schematic configuration diagram showing an optical system configuration of a laser marking device according to a fourth embodiment of the present invention.

FIG. 16 is a schematic configuration diagram of a conventional laser processing apparatus.

FIG. 17 is a schematic configuration diagram showing a configuration of a conventional thin film processing apparatus.

FIG. 18 is a schematic diagram showing changes in laser irradiation spot diameter when a galvano scan is used.

[Explanation of symbols]

1: laser light source 2: laser light 21: second laser light source 22: second laser light 23: second condensing means 3: first condensing means 31: galvano scanner 32: condensing lens 4: Work piece 41: Thin film 42: Glass substrate 5: Support 51: Work piece cooling means 52: Scanning means 81: Heat of laser irradiation section 82: Heat around laser irradiation section 83: Heat of laser irradiation section, Portion cooled by the workpiece cooling means 91: Laser light irradiation spot in the center of the scanning area 92: Laser light irradiation spot in the peripheral area of the scanning area 93: Laser light irradiation spot in the peripheral area of the scanning area

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Koji Uemura             2-1, Kurosaki Shiroishi, Hachiman Nishi-ku, Kitakyushu City, Fukuoka Prefecture               Yasukawa Electric Co., Ltd. (72) Inventor Hajime Tomoe             8-19-1, Nanakuma, Jonan-ku, Fukuoka-shi, Fukuoka Fukuoka             Inside the university (72) Inventor Cui Yun             2-22-2-4 Higashiyasuyama, Jonan-ku, Fukuoka City, Fukuoka Prefecture F-term (reference) 4E068 AA05 AD00 CB06 CE02 CE09                       CG00 DB14

Claims (8)

[Claims] 1. A laser processing apparatus comprising a laser light source, a scanning means for scanning the laser light emitted from the laser light source, and a support base for supporting the workpiece, the laser processing apparatus processing the workpiece with the laser light. 2. The laser processing apparatus according to claim 1, wherein the support table comprises a workpiece cooling means having a groove portion having the same shape as the pattern to be processed on the workpiece. 2. The width of the groove portion of the workpiece cooling means is
The laser processing apparatus according to claim 1, wherein the irradiation spot diameter of the laser beam focused on the workpiece is smaller than that of the laser beam. 3. The laser processing apparatus according to claim 1, wherein the workpiece is a thin film formed on a glass substrate, and the thin film is irradiated with the laser light from the glass substrate side. 4. The laser processing apparatus according to claim 3, wherein the thin film is a diamond-like carbon film. 5. A thin film processing apparatus comprising a first laser light source for irradiating a thin film with a first laser beam and a scanning means for scanning the thin film with the laser beam. A laser processing apparatus comprising a second laser light source for irradiating a second laser beam to a processing groove formed later. 6. The laser processing apparatus according to claim 5, wherein the thin film is a diamond-like carbon film. 7. A method of processing a thin film, which comprises irradiating a laser beam on a thin film to remove a part of the thin film, comprising a step of repeatedly irradiating a processed groove formed after the laser beam irradiation with the laser beam. A method for processing a thin film, which is characterized in that 8. The method of processing a thin film according to claim 7, wherein the thin film is a diamond-like carbon film.