JP2005324215A - 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 capable of enhancing the machining efficiency, preventing damage to a base material, and realizing excellent thin films. <P>SOLUTION: A glass substrate 11 having an insulating film 12 formed thereon is irradiated with laser beams LB to machine the insulating film 12. The nitrogen molar concentration in a vicinity of the position of irradiation of laser beams LB above the glass substrate 11 is set to be higher than that of the atmosphere. Removal of the insulating film 12 is promoted by the reaction of nitrogen with the insulating film 12. The insulating film 12 is efficiently machined even when laser beams LB of low energy are used, and damage to the glass substrate 11 as a base material are also prevented. When a metallic film such as a wire deposited on the insulating film 12 is machined, the metallic film is machined while a part in a vicinity of the position of irradiation of laser beams LB on the glass substrate 11 is evacuated through an exhaust hole 71 of a local exhaust mechanism 70. The nitrogen molar concentration in a vicinity of the position of irradiation of laser beams LB is reduced, and damage to the insulating film 12 are prevented. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a laser processing method and apparatus for correcting defects by irradiating a thin film on a substrate with laser light.

  Conventionally, as one method for patterning a thin film formed on a substrate, a laser processing method is known in which a thin film is removed by irradiating laser light having a pulse width on the order of nanoseconds. This laser processing method is used for correcting defects in photomasks, correcting color filters, correcting wiring on TFT (Thin Film Transistor) substrates, etc. in semiconductor manufacturing or in manufacturing liquid crystal or organic electroluminescence displays. .

  A laser processing apparatus for processing by a laser processing method generally uses a wavelength of 355 nm, which is the third harmonic of a YAG laser, in order to cope with various uses such as color filter correction and substrate wiring correction. ing.

However, when a laser beam having a wavelength of 355 nm is used, it is suitable for processing a metal film such as a wiring, but it is difficult to process an insulating film. This is because the insulating film usually has little absorption at a wavelength of 355 nm. Therefore, even if the insulating film can be processed, the processing speed is remarkably slow, and there is a problem that high energy is required for processing. In order to cope with this problem, for example, it has been proposed to use a wavelength of 266 nm, which is the fourth harmonic of a YAG laser, which is highly absorbed by the insulating film (see, for example, Patent Document 1).
JP 2002-224878 A (paragraph 0006, etc.)

  However, when a laser beam having a wavelength of 266 nm is used, there is a problem that not only the insulating film but also the glass substrate as a base may be processed.

  The present invention has been made in view of such problems, and an object thereof is to provide a laser processing method and apparatus capable of improving the processing efficiency and preventing the damage of the base and processing the target thin film satisfactorily. It is in.

A first laser processing method according to the present invention processes a thin film by irradiating a laser beam onto a substrate on which one or more thin films including an insulating film or a metal film are formed. The processing is performed in a state where the nitrogen (N ₂ ) molar concentration in the vicinity of the irradiation position of the laser beam on the substrate is controlled in accordance with the constituent material. The second and third laser processing methods according to the present invention further embody the first laser processing method according to the processing purpose.

According to a second laser processing method of the present invention, an insulating film is processed by irradiating a laser beam onto a substrate on which one or more thin films including the insulating film are formed. The insulating film is processed with the nitrogen (N ₂ ) molar concentration in the vicinity of the irradiation position being higher than that in the atmosphere. At this time, the nitrogen (N ₂ ) molar concentration in the vicinity of the laser beam irradiation position on the substrate is preferably set to be higher than 44 mol / m ³ . 44 mol / m ³ is the nitrogen molar concentration under atmospheric pressure.

  According to a third laser processing method of the present invention, a metal film is processed by irradiating a laser beam onto a substrate on which one or more thin films including the metal film are formed. The metal film is processed while the vicinity of the irradiation position is evacuated.

A laser processing apparatus according to the present invention includes a mounting table that supports a substrate on which one or more thin films including an insulating film or a metal film are formed, a laser light source that generates laser light toward the substrate supported by the mounting table, A local processing part having a window for transmitting laser light and being relatively displaceable with respect to the surface of the substrate on the mounting table, and supplying nitrogen (N ₂ ) in the vicinity of the irradiation position of the laser light on the substrate And a nitrogen control means for controlling the nitrogen (N ₂ ) molar concentration in the vicinity of the irradiation position of the laser beam on the substrate according to the constituent material of the thin film to be processed.

  In the first laser processing method according to the present invention or the laser processing apparatus according to the present invention, the nitrogen molar concentration in the vicinity of the irradiation position of the laser light on the substrate is controlled according to the constituent material of the thin film to be processed. The reaction rate between nitrogen and the thin film, particularly the insulating film, existing at the irradiation position is optimally controlled according to the processing purpose. This is particularly effective when the insulating film is made of nitride.

In the second laser processing method according to the present invention, since the insulating film is processed in a state where the nitrogen (N ₂ ) molar concentration in the vicinity of the irradiation position of the laser beam on the substrate is higher than the atmosphere, nitrogen and the insulating film are processed. The removal of the insulating film is promoted by the reaction.

  In the third laser processing method according to the present invention, since the metal film is processed in a state where the vicinity of the laser light irradiation position on the substrate is evacuated, the nitrogen molar concentration in the vicinity of the laser light irradiation position is reduced, Even if the metal film is processed to expose the thin film or substrate serving as the base, the reaction rate between the metal film and nitrogen is reduced. Therefore, damage to the base is prevented.

  According to the first laser processing method of the present invention or the laser processing apparatus of the present invention, the nitrogen molar concentration in the vicinity of the irradiation position of the laser beam on the substrate is controlled according to the constituent material of the thin film to be processed. Therefore, the magnitude of the reaction rate between nitrogen existing at the irradiation position of the laser beam and the thin film to be processed can be optimally controlled according to the processing purpose. Therefore, even when laser beams having the same wavelength are used, thin films made of various materials such as insulating films and metal films can be processed efficiently, and damage to the base can be avoided.

According to the second laser processing method of the present invention, the insulating film is processed in a state where the nitrogen (N ₂ ) molar concentration in the vicinity of the irradiation position of the laser beam on the substrate is higher than the atmosphere. The removal of the insulating film can be promoted by the reaction between the insulating film and the insulating film. Therefore, the insulating film can be processed efficiently even when using low-energy laser light, and damage to the base can be effectively prevented.

  According to the third laser processing method of the present invention, since the metal film is processed in a state where the vicinity of the laser light irradiation position on the substrate is evacuated, the nitrogen molar concentration in the vicinity of the laser light irradiation position is set. Even if the metal film is processed and the thin film or the substrate serving as a base is exposed, the reaction rate between the metal film and nitrogen can be reduced. Therefore, damage to the base can be prevented.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view showing the laser processing method according to the first embodiment of the present invention in the order of steps. This laser processing method is used, for example, for forming a liquid crystal window in the manufacture of a display panel such as a liquid crystal or an organic electroluminescence display. First, as shown in FIG. 1A, for example, a glass substrate 11 on which an insulating film 12 is formed is prepared. For example, the insulating film 12 has a thickness in the stacking direction (hereinafter, simply referred to as “thickness”) of about 500 nm, and is made of nitride such as silicon nitride (SiN). Examples of other nitrides constituting the insulating film 12 include titanium nitride (TiN) and aluminum nitride (AlN). The insulating film 12 is not only nitride but also oxynitride such as silicon oxynitride (SiO _x N _y (0 <x <1, 0 <y <1)) or oxide such as silicon oxide (SiO ₂ ). You may be comprised by the thing.

Next, the glass substrate 11 is irradiated with laser light by the laser processing apparatus shown in FIG. This laser processing apparatus includes, for example, a mounting table 20 that supports the glass substrate 11, a laser light source 30 that generates a laser beam LB, and a locally displaceable relative to the surface of the glass substrate 11 on the mounting table 20. A processing unit 40 and a nitrogen control unit 50 for controlling the nitrogen (N ₂ ) molar concentration in the vicinity of the irradiation position of the laser beam on the glass substrate 11 in accordance with the constituent material of the thin film to be processed are provided.

  The mounting table 20 is constituted by, for example, an XY stage so that the glass substrate 11 can be moved relative to the local processing unit 40 and a desired position of the insulating film 12 can be irradiated with the laser beam LB. It has become. Further, the mounting table 20 is provided with a retracting section (not shown) for retracting the local processing section 40 when the glass substrate 11 is mounted or replaced.

  The laser light source 30 is, for example, a third harmonic light source of a YAG laser, and generates laser light LB having a wavelength of 355 nm. Further, between the laser light source 30 and the local processing unit 40, as an irradiation optical system, for example, an aperture (not shown) that shapes the laser light LB, a mirror 31 that changes the traveling direction of the laser light LB, and the laser light LB. Is disposed. The objective lens 32 constitutes an observation unit for observing the processing state of the insulating film 12.

  The local processing unit 40 has a substantially disk shape, and a window 41 and a laser irradiation chamber 42 are provided at the center thereof. The window 41 is for transmitting the laser beam LB, and is made of, for example, a transparent material such as glass having transparency to the laser beam LB. The laser irradiation chamber 42 is closed by the window 41 and the glass substrate 11 side is opened.

The nitrogen control unit 50 includes a nitrogen supply mechanism 60 that supplies a compressed nitrogen gas G1 in the vicinity of the irradiation position of the laser beam LB on the glass substrate 11, and the glass substrate 11 corresponds to the constituent material of the thin film to be processed. The nitrogen (N ₂ ) molar concentration in the vicinity of the irradiation position of the laser beam LB is controlled. Thereby, in this laser processing apparatus, the magnitude of the reaction speed between nitrogen existing at the irradiation position of the laser beam LB and the thin film to be processed is optimally controlled according to the processing purpose.

  Further, the nitrogen control unit 50 includes, for example, a local exhaust mechanism 70 that locally evacuates the vicinity of the irradiation position of the laser beam LB on the glass substrate 11, and a purge gas supply mechanism that blows the purge gas G2 onto the window 41 of the local processing unit 40. 80.

  The nitrogen supply mechanism 60 floats the local processing portion 40 with respect to the TFT substrate 11 with the compressed gas G1 of nitrogen. Further, the nitrogen supply mechanism 60 also has a function as a gas curtain mechanism that blocks the intrusion of outside air into the laser irradiation chamber 42 by the compressed gas G1, and seals the laser irradiation chamber 42 together with the window 41, and the glass substrate 11 The vicinity of the irradiation position of the above laser beam LB is shielded from the outside air.

  The nitrogen supply mechanism 60 includes a ventilation part 61 on the surface of the local processing unit 40 on the mounting table 20 side, and the ventilation part 61 allows compressed gas G1 from a compressed gas supply source (not shown) to be placed on the mounting table 20. It blows out toward the glass substrate 11. Although the ventilation part 61 blows out compressed gas G1, it is comprised by many holes (not shown). The ventilation part 61 is preferably made of, for example, a porous material in order to uniformly release the compressed gas G1. As the porous material, for example, a porous metal, a porous ceramic, or a porous synthetic resin is preferable, and among these, porous aluminum (Al) is more preferable.

Further, the nitrogen supply mechanism 60 has a compressed gas suction port 62 for sucking and exhausting the compressed gas G1 flowing toward the laser irradiation chamber 42 from the compressed gas suction port 62 on the surface of the local processing unit 40 on the mounting table 20 side. have. The nitrogen supply mechanism 60 can control the flying height of the local processing unit 40 by adjusting the pressure or flow rate of the compressed gas G1 and the suction amount from the compressed gas suction port 62 using a valve or the like (not shown). It has become. The nitrogen supply mechanism 60 includes an exhaust processing unit (not shown) that exhausts the compressed gas G1 sucked from the compressed gas suction port 62.

  The local exhaust mechanism 70 includes an exhaust hole 71, for example. The exhaust hole 71 sucks the compressed gas G1 flowing toward the laser irradiation chamber 42 and evacuates it. The local exhaust mechanism 70 includes an exhaust processing unit (not shown) that exhausts the compressed gas G1 and the like sucked from the exhaust hole 71.

  The purge gas supply mechanism 80 blows a purge gas G2 made of an inert gas such as argon (Ar) onto the window 41 in order to prevent scattered matter from adhering to the window 41. The purge gas supply mechanism 80 includes a purge gas supply path 81 for introducing a purge gas G2 from a purge gas supply source (not shown) into the laser irradiation chamber 42. Note that when the insulating film 12 is to be processed as in the present embodiment, nitrogen may be used as the purge gas G2.

  FIG. 3 is a bottom view of the local processing unit 40 as viewed from the mounting table 20 side. In FIG. 3, in order to easily identify the local processing portion 40 and the ventilation portion 61, they are respectively given the same oblique lines as those in FIG. 2. The compressed gas suction port 62 and the ventilation portion 61 are arranged concentrically with the window 41 as the center in this order from the side closer to the window 41.

  This laser processing apparatus operates, for example, as follows.

First, when the glass substrate 11 on which the insulating film 12 is formed is mounted on the mounting table 20, a compressed gas G 1 of, for example, 0.15 MPa is directed toward the glass substrate 11 through the ventilation portion 61 by the nitrogen supply mechanism 60. And blown out. Thereby, the local process part 40 floats. In this way, by causing the local processing portion 40 to float in advance, it is possible to prevent the glass substrate 11 from being damaged by preventing the local processing portion 40 from coming into contact with the glass substrate 11. At this time, a part of the compressed gas G1 flows into the laser irradiation chamber 42, and the nitrogen molar concentration in the laser irradiation chamber 42, that is, in the vicinity of the irradiation position of the laser beam LB on the glass substrate 11, becomes higher than the atmosphere. . The nitrogen molar concentration is preferably larger than 44 mol / m ³ , for example. Note that vacuum exhaust is not performed by the exhaust hole 71 of the local exhaust mechanism 70. This is because the molar concentration of nitrogen is higher than that of the atmosphere.

  Subsequently, for example, 50 ccm of argon (Ar) gas is introduced as the purge gas G2 into the laser irradiation chamber 42 by the purge gas supply mechanism 80.

After that, the glass substrate 11 is moved below the local processing unit 40 by the mounting table 20, and the laser beam LB from the laser light source 30 is irradiated to a desired position of the insulating film 12. The energy of the laser beam LB is, for example, 4.0 J / cm ² or more. Thereby, the insulating film 12 is removed as shown in FIG. By repeating this process, the insulating film 12 is processed into a desired shape. Here, since the processing of the insulating film 12 is performed in a state where the nitrogen molar concentration in the laser irradiation chamber 42, that is, in the vicinity of the irradiation position of the laser light LB on the glass substrate 11, is larger than the atmosphere, the energy of the laser light LB is increased. However, even if it is relatively low, such as 4.0 J / cm ² or more, the removal of the insulating film 12 is promoted by the reaction between nitrogen and the insulating film 12. Moreover, damage to the glass substrate 11 which is a base is also prevented.

  As described above, in this embodiment, since the insulating film 12 is processed in a state where the nitrogen molar concentration in the vicinity of the irradiation position of the laser beam LB on the glass substrate 11 is higher than the atmosphere, the nitrogen and the insulating film 12 are processed. The removal of the insulating film 12 can be promoted by the reaction. Therefore, the insulating film 12 can be efficiently processed even when the low-energy laser beam LB is used, and damage to the glass substrate 11 that is a base can be effectively prevented.

(Second Embodiment)
FIG. 4 is a cross-sectional view showing the laser processing method according to the second embodiment of the present invention in the order of steps. In this laser processing method, not only the insulating film 12 but also a metal film 13 is laminated on the glass substrate 11, and the metal film 13 is an object to be processed. This is the same as the laser processing method described in the embodiment. Accordingly, the corresponding components will be described with the same reference numerals.

  First, as shown in FIG. 4A, for example, a glass substrate 11 in which a metal film 13 is stacked on an insulating film 12 is prepared. The metal film 13 is used as a wiring pattern such as a liquid crystal or an organic electroluminescence display. For example, the metal film 13 has a thickness of about 500 nm and is made of aluminum (Al).

  Next, the glass substrate 11 is irradiated with laser light by the laser processing apparatus shown in FIG. That is, when the glass substrate 11 on which the insulating film 12 is formed is mounted on the mounting table 20, for example, a compressed gas G 1 of 0.2 MPa is directed toward the glass substrate 11 through the ventilation portion 61 by the nitrogen supply mechanism 60. Are blown out, and the locally processed portion 40 rises.

  Subsequently, for example, 50 ccm of argon (Ar) gas is introduced as the purge gas G2 into the laser irradiation chamber 42 by the purge gas supply mechanism 80. In this embodiment, since the metal film 13 is a processing target, the purge gas G2 is a gas other than nitrogen, particularly argon (Ar), helium (He), neon (Ne), krypton (Kr), or xenon (Xe). It is preferable to use an inert gas such as. This is because the nitrogen molar concentration in the vicinity of the irradiation position of the laser beam LB on the glass substrate 11 can be further reduced.

After that, the compressed gas G1 is sucked and exhausted from the compressed gas suction port 62, and the flying height of the local processing unit 40 from the glass substrate 10 is set to 10 μm, for example. Thereby, the flying height of the local processing part 40 is stabilized, and the flying rigidity is increased. Further, the compressed gas G1 is sucked from the exhaust hole 71 of the local exhaust mechanism 70 and evacuated. As a result, the laser irradiation chamber 42, that is, the vicinity of the irradiation position of the laser beam LB on the glass substrate 11, is evacuated, and the nitrogen molar concentration is lowered. At this time, the nitrogen molar concentration is preferably set to 44 mol / m ³ or less, for example.

  After that, the glass substrate 11 is moved below the local processing unit 40 by the mounting table 20, the short-circuited portion to be corrected is aligned with the local processing unit 40, and the short-circuited portion is irradiated with the laser light LB from the laser light source 30. . Thereby, as shown in FIG. 4B, the short-circuit portion of the metal film 13 is cut and corrected. By repeating this process, the short-circuit portion of the metal film 13 is sequentially cut and corrected. Here, since the metal film 13 is processed in a state where the vicinity of the irradiation position of the laser beam LB on the glass substrate 11 is evacuated, the nitrogen molar concentration in the vicinity of the irradiation position of the laser beam LB decreases, and the metal film 13 is reduced. However, even if the insulating film 12 is exposed, the reaction rate between the insulating film 12 and nitrogen is reduced. Therefore, damage to the insulating film 12 as a base is prevented.

  As described above, in this embodiment, since the metal film 13 is processed in a state where the vicinity of the irradiation position of the laser beam LB on the glass substrate 11 is evacuated, the nitrogen molar concentration in the vicinity of the irradiation position of the laser beam LB. Even if the metal film 13 is processed and the insulating film 12 is exposed, the reaction rate between the insulating film 12 and nitrogen can be reduced. Therefore, damage to the insulating film 12 as a base can be prevented.

  Furthermore, specific examples of the present invention will be described.

(Example 1)
Similar to the first embodiment, a glass substrate 11 on which an insulating film 12 made of silicon nitride having a thickness of 500 nm is formed is prepared (see FIG. 1A), and the laser processing apparatus shown in FIG. Thus, the insulating film 12 was processed (see FIG. 1B). At that time, 150 kPa (0.15 MPa) nitrogen was supplied as the compressed gas G1 and argon was introduced as the purge gas G2 at a flow rate of 50 ccm. However, the vacuum exhaust by the exhaust hole 71 of the local exhaust mechanism 70 was not performed, and the nitrogen molar concentration was It was made to become larger than the atmosphere (44 mol / m ³ ). When the energy of the laser beam LB was changed and the energy of the laser beam necessary for removing the insulating film 12 was examined, the insulating film 12 could be removed with an energy of 4.0 J / cm ² or more. Further, when the cross section of the obtained laser processed product was measured with a film thickness measuring device, the insulating film 12 was removed satisfactorily, and the occurrence of damage to the glass substrate 11 was not recognized. The depth from the surface of the recess formed by removing the insulating film 12 was 500 nm. The results of Example 1 are summarized in Table 1.

(Comparative Example 1-1)
The condition of the atmosphere in which neither compressed gas nor purge gas is supplied and vacuum exhaust by the exhaust hole of the local exhaust mechanism is not performed, that is, the molar concentration of nitrogen is the same (44 mol / m ³ ) as in the atmosphere. Except for this, the insulating film was processed in the same manner as in Example 1. When the energy of the laser beam was changed and the energy of the laser beam necessary for removing the insulating film was examined, the insulating film could not be removed even with an energy of 6.0 J / cm ² or more. The results of Comparative Example 1-1 are also shown in Table 1.

(Comparative Example 1-2)
The insulating film was processed in the same manner as in Example 1 except that the nitrogen molar concentration was made lower than the atmosphere (less than 44 mol / m ³ ) by performing vacuum evacuation through the exhaust holes of the local exhaust mechanism. When the energy of the laser beam was changed and the energy of the laser beam necessary for removing the insulating film was examined, the insulating film could not be removed even with an energy of 6.0 J / cm ² or more. The results of Comparative Example 1-2 are also shown in Table 1.

(Comparative Example 1-3)
Insulation was performed in the same manner as in Example 1 except that the nitrogen molar concentration was made lower than the atmosphere (less than 44 mol / m ³ ) by supplying vacuum exhaust through the exhaust hole of the local exhaust mechanism without supplying the purge gas. The membrane was processed. When the energy of the laser beam was changed and the energy of the laser beam necessary for removing the insulating film was examined, the insulating film could be removed with an energy of 5.3 J / cm ² or more. The results of Comparative Example 1-3 are also shown in Table 1.

  As shown in Table 1, according to Example 1, the insulating film 12 could be satisfactorily processed using a low energy laser beam, and damage to the underlying glass substrate 11 was suppressed. In contrast, in Comparative Examples 1-1 and 1-2, the insulating film 12 could not be removed even when the energy of the laser beam was increased. This is considered to be because in Comparative Example 1-1, the nitrogen molar concentration in the vicinity of the irradiation position of the laser beam on the substrate was the same as that in the atmosphere, and the reaction rate between nitrogen and the insulating film was slow. 2, since the vacuum exhaust was performed by the exhaust hole of the local exhaust mechanism, the nitrogen molar concentration in the vicinity of the irradiation position of the laser beam on the glass substrate was lower than that in the atmosphere, and similarly the reaction rate between nitrogen and the insulating film was This is probably because it was late.

Furthermore, in Comparative Example 1-3, the energy of the laser beam necessary for removal could not be improved. The maximum energy of the laser beam varies by a light source to be used, for example, if the maximum energy and 6.0J / cm ² 5.3J / cm ² corresponds to about 90%, and the life of the laser light source is significantly reduced There is a risk that. From this, it is considered that Example 1 that can reduce the energy of the laser beam is more desirable than Comparative Example 1-3.

  That is, the compressed gas G1 and the purge gas G2 are supplied in the vicinity of the irradiation position of the laser beam LB on the glass substrate 11, and the vacuum exhaust by the exhaust hole 71 of the local exhaust mechanism 70 is not performed, and the irradiation of the laser beam LB on the glass substrate 11 is performed. It has been found that if the insulating film 12 is processed in a state where the nitrogen molar concentration in the vicinity of the position is higher than the atmosphere, the removal of the insulating film 12 can be promoted by the reaction between nitrogen and the insulating film 12.

(Example 2)
Similarly to the second embodiment, a glass substrate 11 is prepared on which an insulating film 12 made of silicon nitride having a thickness of 500 nm and a metal film 13 made of aluminum having a thickness of 500 nm are formed (see FIG. 4A). 2), the metal film 13 was processed by the laser processing apparatus shown in FIG. 2 (see FIG. 4B). At that time, 0.2 MPa of nitrogen is supplied as the compressed gas G1, and the floating height of the local processing unit 40 is set to 10 μm by exhausting through the compressed gas suction port 62. Subsequently, argon is used as the purge gas G2 at a flow rate of 50 ccm. After the introduction, vacuum evacuation was performed by the exhaust hole 71 of the local exhaust mechanism 70. When the cross section of the obtained laser processed product was measured with a film thickness measuring device, only the metal film 13 was removed satisfactorily, and the occurrence of damage to the insulating film 12 was not observed. The depth from the surface of the recess formed by removing the metal film 13 was 500 nm.

(Comparative Example 2)
The metal film 13 was processed in the same manner as in Example 2 except that evacuation was not performed by the exhaust holes of the local exhaust mechanism. When the cross section of the obtained laser processed product of Comparative Example 2 was measured with a film thickness measuring device, not only the metal film 13 but also the insulating film 12 was removed (see FIG. 5). The depth from the surface of the recess formed thereby was 1000 nm.

  Thus, in this example, it was possible to process only the metal film 13 to be processed without damaging the insulating film 12 as in Comparative Example 2. This is because when the vacuum exhaust is performed by the exhaust hole 71 of the local exhaust mechanism 70, the nitrogen molar concentration in the vicinity of the irradiation position of the laser beam LB on the glass substrate 11 is lower than the atmosphere, and the reaction between nitrogen and the insulating film 12 occurs. This is probably because the speed has slowed down.

  That is, the compressed gas G1 and the purge gas G2 are supplied to the vicinity of the irradiation position of the laser beam LB on the glass substrate 11, and the vacuum exhaust is performed by the exhaust hole 71 of the local exhaust mechanism 70, thereby the irradiation position of the laser beam LB on the glass substrate 11. If the metal film 13 is processed while the vicinity is evacuated, the nitrogen molar concentration in the vicinity of the irradiation position of the laser beam LB is reduced, and the metal film 13 is formed without damaging the insulating film 12 as a base. It turns out that it can be processed.

  From Examples 1 and 2 above, processing is performed with the nitrogen molar concentration in the vicinity of the irradiation position of the laser beam LB on the glass substrate 11 being controlled according to whether the processing purpose is the insulating film 12 or the metal film 13. As a result, it has been found that the reaction rate between the insulating film 12 and nitrogen existing at the irradiation position of the laser beam LB can be optimally controlled according to the processing purpose.

  Although the present invention has been described with reference to the embodiments and examples, the present invention is not limited to the above embodiments and examples, and various modifications can be made. For example, in the above-described embodiment and examples, the case where only the insulating film 12 or only the insulating film 12 and the metal film 13 are provided on the glass substrate 11 has been described, but between the glass substrate 11 and the insulating film 12 is described. Furthermore, another thin film may be provided. Alternatively, the metal film 13 may be directly formed on the glass substrate 11.

  For example, in the said embodiment and Example, although the case where the glass substrate 11 was moved with respect to the local process part 40 with the mounting base 20 was demonstrated, the laser light source 30 and the local process part 40 are made into the glass substrate 11. You may make it move with respect to it, or you may make it move both.

  Further, for example, in the above-described embodiments and examples, the case where the local processing unit 40 is levitated by the nitrogen supply mechanism 60 using the compressed gas G1 has been described. It is not limited to the pressure levitation method. In addition, the local processing unit 40 may be fixed to, for example, a support column.

  In addition, in the above-described embodiment and example, the ventilation portion 61 and the exhaust hole 71 are formed in an annular shape in the disk-shaped local processing portion 40 as shown in FIG. The shape of the exhaust hole 71 is not limited to an annular shape, and may be, for example, a rectangle or a triangle. However, an annular shape is preferable because it is easy to manufacture.

  Furthermore, the compressed gas G1 or the purge gas G2 is not limited to the gas type described in the above embodiment and examples, and may be other gases.

  The laser processing method and apparatus according to the present invention include, for example, defect correction of a photomask, transparent conductive thin film such as ITO (Indium Tin), in addition to defect correction of the glass substrate 11 for display described in the above embodiments and examples. Oxide (indium oxide added with tin) thin film electrode pattern formation, and trimming of resistors or coils constituted by the thin film can also be applied.

It is sectional drawing showing the laser processing method which concerns on the 1st Embodiment of this invention to process order. It is sectional drawing showing the structure of the laser processing apparatus used with the laser processing method shown in FIG. It is a bottom view showing the structure which looked at the local process part shown in FIG. 2 from the glass substrate side. It is sectional drawing showing the laser processing method which concerns on the 2nd Embodiment of this invention to process order. It is sectional drawing showing the result of the comparative example 2 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Glass substrate, 12 ... Insulating film, 13 ... Metal film, 20 ... Mounting stand, 30 ... Laser light source, 40 ... Local processing part, 41 ... Window, 42 ... Laser irradiation chamber, 50 ... Nitrogen control part, 60 ... Nitrogen Supply mechanism 61 ... venting portion 70 ... local exhaust mechanism 71 ... exhaust hole 80 ... purge gas supply mechanism G1 ... compressed gas G2 ... purge gas

Claims (10)

A laser processing method for processing a thin film by irradiating a laser beam onto a substrate on which one or more thin films including an insulating film or a metal film are formed,
Processing is performed in a state where the nitrogen (N ₂ ) molar concentration in the vicinity of the irradiation position of the laser beam on the substrate is controlled according to the constituent material of the thin film to be processed. A laser processing method for processing the insulating film by irradiating a laser beam onto a substrate on which one or more thin films including the insulating film are formed,
Processing the insulating film in a state where the nitrogen (N ₂ ) molar concentration in the vicinity of the irradiation position of the laser beam on the substrate is higher than the atmosphere. ^3. The laser processing method according to claim 2, wherein a nitrogen (N ₂ ) molar concentration in the vicinity of an irradiation position of the laser beam on the substrate is set larger than 44 mol / m ³ . The laser processing method according to claim 2, wherein the insulating film is made of nitride. A laser processing method for processing the metal film by irradiating a laser beam onto a substrate on which one or more thin films including the metal film are formed,
The metal film is processed in a state where the vicinity of the irradiation position of the laser beam on the substrate is evacuated. The laser processing method according to claim 5, wherein the metal film is processed in a state where an inert gas is supplied in the vicinity of an irradiation position of the laser beam on the substrate. The laser processing method according to claim 5, wherein an insulating film made of nitride is formed between the metal film and the substrate. A mounting table for supporting a substrate on which one or more thin films including an insulating film or a metal film are formed;
A laser light source for generating laser light toward the substrate supported by the mounting table;
A local processing part having a window for transmitting the laser light and being displaceable relative to the surface of the substrate on the mounting table;
A nitrogen supply mechanism for supplying nitrogen (N ₂ ) in the vicinity of the laser beam irradiation position on the substrate, and nitrogen (in the vicinity of the laser beam irradiation position on the substrate in accordance with the constituent material of the thin film to be processed) And N ₂ ) a nitrogen control means for controlling the molar concentration. The laser processing apparatus according to claim 8, wherein the nitrogen control means includes a local exhaust mechanism for locally evacuating the vicinity of the irradiation position of the laser beam on the substrate. The laser processing apparatus according to claim 8, wherein the nitrogen control unit includes a purge gas supply mechanism for supplying an inert gas in the vicinity of an irradiation position of the laser beam on the substrate.

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