KR20050017114A - Method and device for removal of thin-film - Google Patents

Abstract

The laser beam 13 is irradiated to the board | substrate 12 which processed the thin film 11 on the surface, and the thin film 11 of the surface of the board | substrate 12 is removed. The laser beam 13 is irradiated from a direction inclined with respect to the surface of the substrate 12.

Description

Thin Film Removal Method and Apparatus {METHOD AND DEVICE FOR REMOVAL OF THIN-FILM}

The present invention relates to a method and apparatus for removing a thin film on a substrate surface using a laser beam.

Thin film removal using a laser beam is used for thin film pattern formation in semiconductor thin films, thin film solar cells, liquid crystal panels, and the like, organic EL (Electro Luminescence) displays, and transparent multilayer thin film structure products. In the thin film removal using this laser beam, the conventional laser beam was performed by injecting the laser beam perpendicularly to the substrate.

In this case, a method of using a condensing optical system with a very short focal length, using a short wavelength laser, or using a short time irradiation, has been carried out so as not to affect the substrate. In the methods of these (1) to (3), since the appropriate thin film removal conditions vary depending on the raw material, color, and layer structure of the substrate, the substrate state for removing the thin film is limited and processed.

However, in the method of ①, in which the short focusing optical system is used to remove the thin film of the substrate, the depth of focus becomes shallow, so that the positioning accuracy of the laser head and the workpiece becomes strict. Therefore, a high precision processing machine is needed, and the jig | tool which installs a workpiece also needs to be large scale.

For example, it is said that it is effective to use a laser having a shorter wavelength than 1064 nm for removing a thin film made of an ITO (indium tin oxide) layer (method of ②). However, in the conventional vertical incidence, when the black matrix layer exists in a board | substrate, it has been proved by the inventors etc. that a thermal influence is given to this black matrix layer.

In addition, there is a thing called femtosecond laser in implementation of the method of (3). Using this laser, it is possible to remove only the ITO layer, but since this femtosecond laser is very expensive and the energy conversion efficiency is very low, it does not go beyond the research stage.

In addition, in the methods of 1 to 3, proper thin film conditions vary depending on the material, color, layer structure, and the like of the substrate. Therefore, when the state of the material, color, layer structure, etc. is changed on the same substrate, Change or thermally affect the substrate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide a method and an apparatus which can remove a thin film with high positioning accuracy by using an inexpensive and general-purpose laser oscillator.

1 is an explanatory view of a thin film removing method of the present invention.

Fig. 2 is a schematic block diagram showing a first embodiment of the thin film removing apparatus of the present invention for implementing the thin film removing method of the present invention, (a) using an optical fiber, and (b) using an optical system.

Fig. 3 is a schematic block diagram showing a second embodiment of the thin film removing apparatus of the present invention for carrying out the thin film removing method of the present invention, (a) using an optical fiber and (b) using an optical system.

4 is a schematic structural diagram showing a third embodiment of the thin film removing apparatus of the present invention for implementing the thin film removing method of the present invention.

5 (a) and 5 (b) are schematic diagrams showing a fourth embodiment of the thin film removing apparatus of the present invention for implementing the thin film removing method of the present invention.

6 is a graph showing the relationship between the absorption rate and the irradiation angle when the laser beam is irradiated onto the thin film.

7 is a diagram illustrating an example of an energy distribution of a laser beam, and is a diagram of a Gaussian mode.

FIG. 8 is a diagram illustrating an example of energy distribution of a laser beam, and is a diagram of a top hat beam mode. FIG.

Fig. 9 (a) is a diagram of energy density molded into a top hat shape, 9 (b) is a cross sectional view of a laser beam formed into a rectangular shape, and 9 (c) is a cross sectional view of a laser beam formed into a line shape.

10 (a) and 10 (b) show an embodiment of a beam shaping optical system, and 10 (c) shows a configuration of an embodiment of an optical system.

It is a figure explaining the directionality of the process at the time of irradiating a laser beam from the inclined direction.

12 is a diagram illustrating a photograph of a thin film removal result in the conventional method in the case of low power.

Fig. 13 is a diagram illustrating a photograph of thin film removal results in the conventional method in the case of medium power.

Fig. 14 is a diagram illustrating a photograph of thin film removal results in the conventional method in the case of high power.

15 is a diagram illustrating a photograph of a thin film removal result of the present invention.

The thin film removal method of this invention irradiates the laser beam irradiated to the board | substrate which processed the thin film from the direction inclined with respect to the said board | substrate surface. By doing this, it is possible to remove only the thin film surface of the portion to which the laser beam is irradiated, without influencing the substrate.

The thin film removing method of the present invention includes, for example, a laser oscillator, an optical system for transmitting a laser beam emitted from the laser oscillator, and beam inclination means for inclining the laser beam irradiated from the optical system with respect to a substrate surface. It can carry out by the thin film removal apparatus of this invention provided.

The relationship between the absorption rate and the irradiation angle (angle from the direction perpendicular to the thin film surface) when the laser beam is irradiated to the thin film is shown in FIG. 6. The degree of irradiation angle is large and the beam path in the thin film layer to be processed. It becomes long and it turns out that it has the characteristic that the absorption amount of a laser beam becomes large.

In addition, when irradiating a laser beam from the inclined direction, the depth of focus of the pseudo vertical direction with respect to a to-be-processed material becomes shallow. Thereby, the effect similar to the case of using a short focusing optical system can also be exhibited. In addition, it goes without saying that the depth of focus is sufficiently deep as compared with the conventional method using a single focusing optical system.

MEANS TO SOLVE THE PROBLEM This inventor established the following this invention which can remove only a thin film in the state which does not give a thermal influence to a board | substrate by these synergistic effects based on said knowledge.

That is, the thin film removal method of this invention irradiates a laser beam with respect to the board | substrate which processed the surface thin film, and irradiates the said laser beam from the direction inclined with respect to the said substrate surface in the method of removing the thin film of the substrate surface. will be.

According to the experiments of the present inventors, in the thin film removing method of the present invention, it is found that the inclined direction with respect to the substrate surface is effective when inclined at 40 ° to 89 ° from the direction perpendicular to the substrate surface.

When the inclined direction with respect to the substrate surface is less than 40 ° from the direction perpendicular to the substrate surface, as shown in FIG. 6, when the absorption rate of the laser beam is irradiated perpendicularly to the conventional substrate surface (= 0 °) This is because the time required for removing the thin film is long because it does not get much better than that, which adversely affects the substrate. In addition, when it exceeds 89 degrees, the inclination angle of the laser beam with respect to a board | substrate becomes too large, the absorption rate of a laser beam falls rapidly, and thin film removal is not possible. According to the experiments of the present inventors, more preferable results were obtained in the case of 55 ° to 89 °.

In the thin film removing method of the present invention, the laser beam is not continuously irradiated, but when the laser beam is irradiated at a repetition frequency of 0.1 kHz to 300 kHz, the dissolution of the laser is less, resulting in a smaller thermal effect on the substrate. can do. According to the experiments of the present inventors, more preferable results were obtained in the case of 1 kHz to 300 kHz.

In the thin film removing method of the present invention, even if the thickness of the thin film on the substrate surface is 10 μm or less, ITO, IZO (indium zinc oxide), acrylic resin, phenol resin, novolac resin, Thin films of polyimide resins, Ag, Ag alloys, Al, A1 alloys, Ti, Ti alloys, Cu, Cu alloys, Mo, Ta, Si, SiO ₂ and SiN were efficiently removed.

By the way, in normal laser processing and laser cutting, although the laser beam of the energy distribution as shown in FIG. 7 called a Gaussian mode is irradiated, when a thin film is removed only using the laser beam of the energy distribution of this Gaussian mode, Dissolution becomes more severe and tends to have a thermal effect on the substrate.

Therefore, as a laser beam used for planar processing such as the thin film removing method of the present invention, a top hat shape as shown in FIG. 8, which hardly affects a substrate during thin film removal, is used. It is preferable to use a laser beam where the top of the multi-mode) is flat and the energy distribution is as constant as possible.

This top hat-shaped laser beam having a constant energy distribution is usually formed by a homogenizer or a homogeneous optical system. According to the experiments of the present inventors, the roughness of the upper flat portion is about ± 5%. Since it has been found that there is no problem in the thermal effect on the substrate when the thin film is removed, in the present invention, a laser beam made of a top hat-shaped energy distribution may be used by transmitting using an optical fiber.

The thin film removing method of the present invention comprises a substrate having a laser oscillator, an optical system or optical fiber for transmitting a laser beam emitted from the laser oscillator, and a laser beam irradiated from a laser head attached to the tip of the optical system or optical fiber. It can be implemented by the thin film removing device of the present invention having a beam inclination means for inclining relative to. The beam tilting means constituting the thin film removing apparatus of the present invention may incline the optical system or the laser head with respect to the thin film to be removed, and the irradiated laser beam may be removed from the thin film to be removed through an optical system such as a mirror. It may also be inclined with respect.

In the thin film removing method of the present invention, among the laser beams having a top hat shape where the energy distribution as shown in FIG. 9 (a) is as constant as possible, a cross section as shown in FIG. 9 (b) has a rectangular laser beam. When used, the processing state of both side and center part in line processing becomes equal. In addition, when a laser beam having a linear cross section as shown in Fig. 9 (c) is used, the processing area per shot is small, so that for example, when patterning is performed, Freedom is created. The energy distribution in one direction of the laser beam is formed in the linear cross section by an optical system having a function of a Gaussian distribution having a high energy density in the center, and the energy distribution in the direction orthogonal to this is formed in a uniform top hat shape. When one laser beam is used, processing can be performed even with a relatively low power laser oscillator.

This laser beam is homogenized into a top hat shape by a homogenizer 31a (fly's eye lens, etc.) and a condenser lens 31b (condenser lens), as shown in FIG. The beam shaping optical system 31 which forms a rectangular cross section of the solution, or as shown in Fig. 10 (b), by the homogenizer 31a (prism or the like) and the cylindrical lens 31c (cylindrical lens) It is also possible to use the beam shaping optical system 31 which uniforms the top hat shape and forms the cross section in a linear shape, or may use a rectangular or linear slit. As shown in Fig. 10C, both the above-described beam shaping optical system 31 and the slit 32 for equalizing the intensity of the laser beam 13 formed by the beam shaping optical system 31 are used. Also good. In addition, reference numeral 33 in FIG. 10 (c) shows an imaging optical system that zooms or focuses a laser beam with uniform intensity in the slit 32. Moreover, you may use an optical fiber as a means to uniformize a laser beam to a top hat shape.

Moreover, when this cross section makes it possible to adjust the longitudinal dimension of a rectangular laser beam, and the cross section has a linear width dimension, thin film removal can be performed more suitably according to the kind, thickness, etc. of the thin film to remove. .

As an optical system that can adjust the longitudinal and width dimensions of the laser beam described above, it is possible to set the projection ratio of a pattern formed by an imaging lens between the oscillator and the workpiece, but it can be used in the vertical or horizontal direction. It is good to use the thing which made it possible to set the cross-sectional shape of the laser beam to irradiate by forming the slit which enables the dimension adjustment of the laser beam.

In the thin film removing method of the present invention, the energy distribution in one direction of the cross-sectional shape of the laser beam 13 in the beam shaping optical system 31 is represented by, for example, an arc. The top hat shape is uniformed by the mongerizer 31a (or uniform optical system), and the energy distribution in the direction orthogonal to this is, for example, a linear cross-sectional shape of the Gaussian distribution by an optical system including a cylindrical lens. When one laser beam is used, the linear laser beam can be formed at the lowest cost.

The thin film removing method of the present invention is characterized in that the laser beam is irradiated from the inclined direction with respect to the substrate surface. However, since the laser beam is irradiated from the inclined direction, directionality appears in the laser beam.

Thus, for example, as shown in FIG. 11, ITO is disposed on the surface of the substrate 1 having the black matrix layer 1c interposed therebetween at a predetermined position between the glass layer 1a and the acrylic layer 1b. In the case where the thin film of the layer 2 is formed, a step is caused by the presence or absence of the black matrix layer 1c, and in the laser beam 3 irradiated only from the same inclined direction, the part is shadowed by the step. This appears, making it difficult to remove the ITO layer 2 in the portion where the shadow is formed. In addition, 4 in FIG. 11 shows a laser head.

In the case of removing the thin film having such a step, in order to prevent the occurrence of the shadowed portion, a plurality of optical systems or laser heads for irradiating the laser beam are arranged with a different direction of the thin film to be removed on the substrate surface. The optical system or the laser head may be selected in accordance with the direction of removal, or a set of the optical system or the laser head may be rotatably installed, and the irradiation direction of the optical system or the laser head may be changed in accordance with the direction of thin film removal.

In addition, the above-described method of the present invention includes arranging a plurality of optical systems or optical fibers and laser heads that emit laser beams of the thin film removal apparatus of the present invention by changing the direction of the substrate surface with respect to the thin film to be removed, In the thin film removal apparatus provided with the switching means of the laser beam to an optical system or an optical fiber, or the rotation mechanism of an optical system or a laser head is provided, and the irradiation direction of the said optical system or a laser head is changed according to the direction of thin film removal. This can be done.

In the thin film removing apparatus of the present invention, a position detector for detecting the movement amount of the member to be processed and a first controller for controlling the oscillation operation of the laser oscillator based on the movement amount detected by the position detector are provided. For example, patterning is performed with high accuracy.

Further, when an attenuator is provided in the optical path of the laser beam emitted from the laser oscillator, the laser output is adjusted without disturbing the shape of the laser beam.

By the way, in the process using a laser beam, even when processing with a constant output, a laser output changes every time. At this time, an output detector for detecting the output of the laser beam emitted from the laser oscillator, a second controller for commanding an output corresponding to a change in the signal obtained by the output detector, and a laser oscillator in response to a command from the second controller In a device having a current regulator or an attenuator for adjusting the current of the current, the feedback control of the laser output is optimally performed when a laser output adjusting means comprising an attenuator regulator for receiving a command from the second controller and adjusting the attenuator is provided. It becomes.

In order to demonstrate this invention further in detail, it demonstrates along FIG. 1 is a view for explaining a thin film removing method of the present invention, as shown in FIG. 1, in the present invention, an acrylic layer or an acrylic layer and a black matrix layer coated with a thin film 11, such as an ITO layer, on the surface; An optical system having a function of transmitting energy from an optical fiber or irradiating a substrate 12 made of a glass layer or the like to make the energy distribution of a laser beam constant. For example, a wavelength of 1064 nm having a top hat-shaped energy distribution. The laser beam 13 is irradiated at a repetition frequency of 100 kHz from a direction inclined with respect to the surface of the substrate 12, for example, 70 ° inclined from a direction perpendicular to the surface of the substrate 12.

In the thin film removing method of the present invention, the thin film 11 irradiated with the laser beam 13 without affecting the substrate 12 even in a state where the material, color, layer structure, etc. are changed on the same substrate 12. ) Surface can be removed using inexpensive, general-purpose YAG lasers or YVO ₄ lasers.

In the thin film removing method of the present invention, as shown in FIG. 2, for example, the laser beam emitted from the YAG laser oscillator 21 is transmitted to the optical fiber 22 in FIG. In b), by forming with the beam shaping optical system 31 as described in FIG. And the beam which consists of two mirrors 24a and 24b, for example, the laser beam 23 irradiated by the laser head 23 attached to the front-end | tip of the said optical fiber 22, and the said beam shaping optical system 31, for example. The inclination means 24 can be used by the thin film removing apparatus of the present invention inclined with respect to the surface of the substrate 12. In addition, in FIG. 2, 12a shows the glass layer which comprises the board | substrate 12, 12b shows the same acryl layer, 12c shows the black matrix layer, and 34 shows the reflection mirror.

The beam tilting means 24 constituting the thin film removing apparatus of the present invention can tilt the laser beam 13 irradiated from the beam shaping optical system 31 or the laser head 23, as shown in FIG. It is not limited to using two mirrors 24a and 24b as described above. For example, the beam shaping optical system 31 or the laser head 23 itself may be inclined by an appropriate inclination means.

In addition, when the beam inclination means 24 of the thin film removal apparatus of this invention is set as the structure which can be rotated centering on the irradiation position of the laser beam 13, as shown by the hollow arrow in FIG. The directionality of the processing produced by irradiating the beam 13 from the inclined direction can be eliminated. Therefore, even when a step is caused in the thin film 11 due to the presence of the black matrix layer 12c as shown in FIG. 2, the thin film 11 at this end can also be removed.

FIG. 3 shows the optical fiber 22 and the laser head 23 in FIG. (A), and in FIG. (B) instead of making the beam tilting means 24 rotatable as shown in FIG. The beam shaping optical system 31 is arranged to change the direction of the thin film 11 to be removed on the surface of the substrate 12, for example, and two laser beams are provided to the optical fiber 22 or the beam shaping optical system 31. By providing the switching means 25 of the beam 13, it performs the same function as FIG. In addition, the switching means 25 arrange | positions a mirror so that a laser beam 13 may inject into either the optical fiber 22 or the beam shaping optical system 31, for example. 3 (b) shows that the controller 35 controls the movement of the movement table 36 on which the substrate 12 is loaded and the output of the YAG laser oscillator 21.

Fig. 4 is a position detector which detects the movement amount of the substrate 12 in the case where the switching means 25 is omitted with one beam shaping optical system 31 of the thin film removing device of the present invention shown in Fig. 3B. (37) is provided so that the movement amount detected by the position detector 37 is output to the controller 35. Then, the controller 35 controls the oscillation operation of the YAG laser oscillator 21 by changing the parameter that is input in advance based on this movement amount, thereby improving the machining position accuracy.

FIG. 5A shows an output detector 38 for detecting the output of the laser beam 13 emitted from the YAG laser oscillator 21 instead of the position detector 37 of the thin film removing apparatus of the present invention shown in FIG. The controller 39 inputs the output signal detected by the said output detector 38, and instructs the YAG laser oscillator 21 the output corresponding to the change.

5 (b) is provided with an attenuator 40 in the optical path of the laser beam 13 emitted from the YAG laser oscillator 21 in FIG. 5 (a), and the controller 39 is an output detector 38. Command to the attenuator 40 instead of the YAG laser oscillator 21.

In the thin film removing apparatus of the present invention shown in Fig. 5, the feedback control of the laser output which is changed from time to time is optimally performed. At that time, when the attenuator 40 is provided, the laser output is adjusted without disturbing the shape of the laser beam 13.

In this regard, the experimental results performed to confirm the effects of the present invention described above will be described. The experiment was carried out using a thin film substrate (glass layer: thickness 2 mm, acrylic layer: thickness 1.6 μm, black matrix layer: thickness 1 μm, ITO layer: thickness 0.1 μm) having the configuration shown in FIG. This was done by comparing the conventional method of injecting a laser beam with the method of the present invention in which the laser beam is incident at a repetition frequency of 100 kHz by tilting at an angle of 70 degrees.

12-14 show the result of removing a thin film by the conventional method, and FIG. 15 shows the result of removing the thin film by the method of this invention of Claim 5 using the apparatus of this invention of the structure shown to FIG. 2 (a). It is a figure which drew the photograph seen from the state, and the comparatively black part of each right half part is transparent, for example, the processing example on a black matrix layer, and the comparatively white part of the left half part is an example of processing in the part without a black matrix layer. These figures compare the removal situation of the thin film (ITO layer) with the degree of discoloration (darkening) on the black matrix layer.

Fig. 12 shows the result of the low output (2.9 W), and because of low heat input, the thin film (ITO layer) cannot be removed in the part without the black matrix layer on the left side of the paper. On the other hand, although the thin film (ITO layer) is removed in the part with the black matrix layer on the right side of the paper, it is found that there is a slight thermal effect on the layers other than the thin film (ITO layer).

FIG. 13 shows the case of medium power (7.5W), while FIG. 14 shows the case of high power (41W), but these are larger in heat input than those shown in FIG. The thin film (ITO layer) can be removed. On the other hand, in the part with the black matrix layer on the right side of the paper, it is found that the thermal influence is given to layers other than the thin film (ITO layer).

On the other hand, in the method of the present invention shown in Fig. 15, only the thin film (ITO layer) is removed with or without the black matrix layer, and it is found that there is no thermal effect on the other layers.

The results of the above experiment are shown in Table 1 below, and according to the present invention, the thin film can be removed regardless of the change of the layer.

Table 1

Transparent Black part Removal status of thin film (ITO layer) Integrity other than thin film (ITO layer) Removal status of thin film (ITO layer) Integrity other than thin film (ITO layer) Conventional method (low power) × ○ ○ △ Conventional method (medium output) ○ ○ ○ △ Conventional method (high power) ○ ○ ○ × The present invention ○ ○ ○ ○

Note) Thin film removal status: × cannot be removed and ○ can be removed.

    Integrity other than thin film: × is the degree of heat effect, △ is the degree of heat effect

    Is small and ○ has no heat effect.

In the example of the method of this invention, although the method of Claim 5 provided with the structure of Claim 1 thru | or 3 was shown, the method of any one of Claims 1-3 is a conventional method, It goes without saying that there is a sufficient working effect in comparison.

As described above, according to the present invention, even when the state of material, color, layer structure, etc. is changed on the same substrate, the removal state of the thin film does not change, and furthermore, by using an inexpensive and general-purpose laser oscillator, Thin film removal is possible with positioning accuracy.

Claims (24)

In the method of irradiating a laser beam with respect to the board | substrate with which the surface was thin-film-processed, and removing the thin film of the board | substrate surface, And the laser beam is irradiated from a direction inclined with respect to the substrate surface. The method of claim 1, The inclined direction with respect to the substrate surface is a direction inclined 40 to 89 ° in the direction perpendicular to the substrate surface. The method according to claim 1 or 2, And irradiating the laser beam at a repetition frequency of 0.1 kHz to 300 kHz. The method according to claim 1 or 2, And a laser beam having a uniform top hat energy distribution by transmission of an optical system or an optical fiber having a function of making the energy distribution of the laser beam constant. The method of claim 3, wherein A thin film removal method characterized by using a laser beam having a uniform top hat-shaped energy distribution by transmission of an optical system or an optical fiber having a function of making the energy distribution of the laser beam constant. The method according to claim 1 or 2, The use of a laser beam having a linear cross-sectional shape by an optical system having a function of making the energy distribution in one direction of the cross-sectional shape of the laser beam into a uniform top hat shape and the energy distribution of the orthogonal direction to a Gaussian distribution. Thin film removal method characterized in that. The method of claim 3, wherein A laser beam having a linear cross-sectional shape is used by an optical system having a function of making the energy distribution in one direction of the cross-sectional shape of the laser beam into a uniform top hat shape and the energy distribution in the orthogonal direction as a Gaussian distribution. Thin film removal method. The method according to claim 1 or 2, Arrange a plurality of optical systems or laser heads for irradiating the laser beam in the direction of the thin film to be removed on the substrate surface, and select the optical system or laser head in accordance with the direction of thin film removal, Or a pair of the optical system or the laser head is rotatably installed, and the irradiation direction of the optical system or the laser head is changed in accordance with the direction of the thin film removal. The method of claim 3, wherein Arrange a plurality of optical systems or laser heads for irradiating the laser beam in the direction of the thin film to be removed on the substrate surface, and select the optical system or laser head in accordance with the direction of thin film removal, Or a pair of the optical system or the laser head is rotatably installed, and the irradiation direction of the optical system or the laser head is changed in accordance with the direction of the thin film removal. The method of claim 4, wherein Arrange a plurality of optical systems or laser heads for irradiating the laser beam in the direction of the thin film to be removed on the substrate surface, and select the optical system or the laser head according to the direction of thin film removal. Or a pair of the optical system or the laser head is rotatably installed, and the irradiation direction of the optical system or the laser head is changed in accordance with the direction of the thin film removal. The method of claim 5, Arrange a plurality of optical systems or laser heads for irradiating the laser beam in the direction of the thin film to be removed on the substrate surface, and select the optical system or the laser head according to the direction of thin film removal. Or a pair of the optical system or the laser head is rotatably installed, and the irradiation direction of the optical system or the laser head is changed in accordance with the direction of the thin film removal. The method of claim 6, Arrange a plurality of optical systems or laser heads for irradiating the laser beam in the direction of the thin film to be removed on the substrate surface, and select the optical system or the laser head according to the direction of thin film removal. Or a pair of the optical system or the laser head is rotatably installed, and the irradiation direction of the optical system or the laser head is changed in accordance with the direction of the thin film removal. The method of claim 7, wherein Arrange a plurality of optical systems or laser heads for irradiating the laser beam in the direction of the thin film to be removed on the substrate surface, and select the optical system or the laser head according to the direction of thin film removal. Or a pair of the optical system or the laser head is rotatably installed, and the irradiation direction of the optical system or the laser head is changed in accordance with the direction of the thin film removal. And a laser oscillator, an optical system or an optical fiber for transmitting the laser beam emitted from the laser oscillator, and beam inclination means for inclining the laser beam irradiated from the laser head provided at the tip of the optical system or the optical fiber with respect to the substrate surface. Thin film removal apparatus, characterized in that. The method of claim 14, Arrange a plurality of optical systems or optical fibers and laser heads for emitting the laser beam by changing the direction of the substrate surface to be removed, and providing a means for switching the laser beams to the optical systems or optical fibers. Or a rotation mechanism of the optical system or the laser head, wherein the irradiation direction of the optical system or the laser head is changed in accordance with the direction of removing the thin film. The method according to claim 14 or 15, And a first controller for controlling the oscillation operation of the laser oscillator based on the movement amount detected by the position detector. The method according to claim 14 or 15, And attenuator provided in the optical path of the laser beam emitted from the laser oscillator. The method of claim 16, And attenuator provided in the optical path of the laser beam emitted from the laser oscillator. The method according to claim 14 or 15, An output detector for detecting the output of the laser beam emitted from the laser oscillator, a second controller for commanding an output corresponding to a change in the signal obtained by the output detector, and a current of the laser oscillator in response to a command from the second controller Thin film removal apparatus characterized by comprising a laser output adjusting means consisting of a current regulator for adjusting the. The method of claim 16, An output detector for detecting the output of the laser beam emitted from the laser oscillator, a second controller for commanding an output corresponding to a change in the signal obtained by the output detector, and a current of the laser oscillator in response to a command from the second controller Thin film removal apparatus characterized by comprising a laser output adjusting means consisting of a current regulator for adjusting the. The method of claim 17, An output detector for detecting the output of the laser beam emitted from the laser oscillator, a second controller for commanding an output corresponding to a change in the signal obtained by the output detector, and a current of the laser oscillator in response to a command from the second controller Thin film removal apparatus characterized by comprising a laser output adjusting means consisting of a current regulator for adjusting the. The method of claim 18, An output detector for detecting the output of the laser beam emitted from the laser oscillator, a second controller for commanding an output corresponding to a change in the signal obtained by the output detector, and a current of the laser oscillator in response to a command from the second controller Thin film removal apparatus characterized by comprising a laser output adjusting means consisting of a current regulator for adjusting the. The method of claim 17, An output detector for detecting the output of the laser beam emitted from the laser oscillator, a second controller for commanding an output corresponding to a change in the signal obtained by the output detector, and an adjustment from the second controller upon receiving a command from the second controller And a laser output adjusting means comprising an attenuator adjuster. The method of claim 18, An output detector for detecting the output of the laser beam emitted from the laser oscillator, a second controller for commanding an output corresponding to a change in the signal obtained by the output detector, and an adjustment from the second controller upon receiving a command from the second controller And a laser output adjusting means comprising an attenuator adjuster.