WO2022196056A1

WO2022196056A1 - Inspection apparatus, inspection method, and laser machining apparatus

Info

Publication number: WO2022196056A1
Application number: PCT/JP2022/000790
Authority: WO
Inventors: 哲平田中
Original assignee: 住友重機械工業株式会社
Priority date: 2021-03-17
Filing date: 2022-01-12
Publication date: 2022-09-22
Also published as: TW202237312A; JPWO2022196056A1

Abstract

This inspection apparatus inspects a laser machining apparatus provided with at least one optical component having an interface that refracts or reflects a machining laser beam. An inspection optical system makes an inspection laser beam enter the interface of the optical component to be inspected so that a beam spot in the interface of the optical component to be inspected becomes smaller than a passing area of the machining laser beam, and scans with the beam spot of the inspection laser beam in the interface. A light intensity measuring device measures the light intensity of the inspection laser beam that has passed through or reflected at the interface of the optical component to be inspected. Provided is the inspection apparatus capable of inspecting dirt or flaws smaller than the size of a beam section of the machining laser beam.

Description

Inspection device, inspection method, and laser processing device

The present invention relates to an inspection device for a laser processing device, an inspection method, and a laser processing device.

A laser processing device capable of online monitoring of a decrease in light intensity caused by contamination or deterioration of optical components is known (see Patent Document 1). In the laser processing apparatus described in Patent Document 1, a laser beam for processing is made incident on an optical component, and scattered light from the optical component is observed.

JP 2018-018909 A

If the dirt on the optical parts, the scratches on the optical parts, etc. are smaller than the size of the beam cross-section of the laser beam, the detection sensitivity for dirt, scratches, etc. will be low. For this reason, it is difficult to detect dirt and scratches that are extremely small compared to the size of the beam cross section.

An object of the present invention is to provide an inspection apparatus and an inspection method capable of detecting stains, flaws, etc., which are smaller than the size of the beam cross-section of the processing laser beam. Another object of the present invention is to provide a laser processing apparatus capable of detecting stains, scratches, etc., which are smaller than the size of the beam cross-section of the processing laser beam.

According to one aspect of the invention,
An inspection device for inspecting a laser processing device including at least one optical component having an interface that refracts or reflects a processing laser beam,
The inspection laser beam is incident on the interface of the optical component to be inspected so that the beam spot at the interface of the optical component to be inspected of the laser processing apparatus is smaller than the passing area of the processing laser beam, and an inspection optical system for scanning the beam spot of the inspection laser beam;
and a light intensity measuring device for measuring the light intensity of the inspection laser beam transmitted through or reflected by the interface of the optical component to be inspected.

According to another aspect of the invention,
An inspection method for inspecting a laser processing apparatus having at least one optical component having an interface that refracts or reflects a processing laser beam,
The beam spot of the inspection laser beam is scanned within the interface under the condition that the beam spot of the inspection laser beam at the interface of the optical component to be inspected of the laser processing apparatus is smaller than the passing area of the processing laser beam. ,
An inspection method is provided for measuring the light intensity of the inspection laser beam transmitted through or reflected by the interface of the optical component to be inspected.

According to yet another aspect of the invention,
a laser oscillator that outputs a processing laser beam;
at least one optical component disposed on the path of the processing laser beam from the laser oscillator to the object and having an interface that refracts or reflects the processing laser beam;
The inspection laser beam is incident on the interface of the optical component so that the beam spot at the interface of the optical component is smaller than the passing area of the processing laser beam, and the beam spot of the inspection laser beam is scanned within the interface. an inspection optical system for
and a light intensity measuring device for measuring the light intensity of the inspection laser beam transmitted through or reflected by the interface of the optical component.

By making the beam spot of the inspection laser beam smaller than the passing area of the processing laser beam, it is possible to increase the detection sensitivity for dirt and scratches that are small compared to the size of the passing area of the processing laser beam.

FIG. 1 is a schematic diagram of a laser processing apparatus according to one embodiment. FIG. 2 is a block diagram of an inspection processor. FIG. 3A is a schematic front view of an optical component, and FIG. 3B shows an example of temporal change in light intensity measured by a light intensity measuring device while an inspection laser beam is incident on the optical component. graph. FIG. 4 is a flow chart showing a procedure for inspecting a laser processing apparatus using an inspection apparatus according to an embodiment. FIG. 5 is a schematic diagram of a laser processing apparatus according to another embodiment. FIG. 6 is a schematic diagram of a laser processing apparatus according to still another embodiment. FIG. 7 is a schematic diagram of a laser processing apparatus according to still another embodiment. FIG. 8 is a schematic diagram of a laser processing apparatus according to still another embodiment. FIG. 9 is a schematic diagram of a laser processing apparatus according to still another embodiment. FIG. 10 is a schematic diagram of a laser processing apparatus according to still another embodiment.

A laser processing apparatus and an inspection apparatus therefor according to an embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a schematic diagram of a laser processing apparatus according to one embodiment. A processing laser oscillator 50 outputs a processing laser beam 40 . In FIG. 1, the optical axis of the processing laser beam 40 is indicated by a chain double-dashed line. A processing laser beam 40 enters an object 60 via an optical component 51 such as a lens and other optical components 52 . A target object 60 is held on the stage 53 .

As an example, the processing laser oscillator 50 is a laser diode, a solid-state laser oscillator such as an Nd:YAG laser, an excimer laser oscillator, or the like. The optical component 51 is, for example, one lens out of a plurality of lenses forming a beam expander. Other optical components 52 include the remaining lenses that make up the beam expander, a beam homogenizer, a galvanometer scanner, an fθ lens, a beam transmission window, and the like. The object 60 is a semiconductor wafer implanted with dopant ions, and is subjected to activation annealing by the processing laser beam 40 .

The laser processing apparatus according to this embodiment includes an inspection device in addition to these optical components. The inspection apparatus includes an inspection optical system 10 , a light intensity measuring device 20 , an inspection processing device 25 and an output device 26 . The inspection optical system 10 includes an inspection laser oscillator 11 , a condenser lens 12 , a beam scanner 13 and a moving mechanism 14 . The beam scanner 13 is, for example, a galvanometer scanner including a pair of oscillating

mirrors

13A and 13B. By driving the moving mechanism 14, the swinging mirror 13B has a position (hereinafter referred to as an inspection position) blocking the path of the processing laser beam 40 and does not spatially interfere with the path of the processing laser beam 40. position (hereinafter referred to as standby position). In FIG. 1, the swing mirror 13B at the inspection position is indicated by a solid line, and the swing mirror 13B at the standby position is indicated by a broken line. A double arrow indicates the direction in which the swing mirror 13B translates.

The inspection laser oscillator 11 outputs an inspection laser beam 30 . The inspection laser beam 30 may be a continuous wave laser beam or a pulse laser beam. With the oscillating mirror 13B placed at the inspection position, the inspection laser beam 30 enters the optical component 51 via the condenser lens 12, the oscillating mirror 13A, and the oscillating mirror 13B. The optical component 51 has two interfaces that refract the laser beam. These two interfaces correspond to the surface of the lens.

The condenser lens 12 converges the inspection laser beam 30 so that the beam spot of the inspection laser beam 30 at the two interfaces of the optical component 51 is smaller than the passing area of the processing laser beam 40 . Beam scanner 13 moves the beam spot within the surface of optical component 51 . One oscillating mirror 13A and the other oscillating mirror 13B of the beam scanner 13 move beam spots in mutually orthogonal directions. In FIG. 1, the oscillating mirror 13A moves the beam spot in a direction perpendicular to the paper, and the oscillating mirror 13B moves the beam spot in a direction parallel to the paper.

The light intensity measuring device 20 is translated by the moving mechanism 21 between an inspection position that blocks the path of the processing laser beam 40 and a standby position that does not spatially interfere with the path of the processing laser beam 40 . In FIG. 1, the light intensity measuring device 20 at the inspection position is indicated by a solid line, and the light intensity measuring device 20 at the standby position is indicated by a broken line. The directions in which the light intensity measuring device 20 translates are indicated by double arrows.

The inspection laser beam 30 that has passed through the optical component 51 is incident on the light intensity measuring device 20 . The light intensity measuring device 20 measures the light intensity of the incident inspection laser beam 30 . A measurement result obtained by the light intensity measuring device 20 is input to the inspection processing device 25 .

FIG. 2 is a block diagram of the processing device 25 for inspection. The inspection processing device 25 includes a laser oscillation control section 25A, a moving mechanism control section 25B, a beam scanning control section 25C, a light intensity measurement section 25D, and an output control section 25E. The laser oscillation control unit 25A controls the inspection laser oscillator 11 to output an inspection laser beam. The moving mechanism controller 25B controls the moving

mechanisms

14 and 21 to move the swing mirror 13B (FIG. 1) and the light intensity measuring device 20 (FIG. 1) between the standby position and the inspection position.

The beam scanning controller 25C controls the beam scanner 13 to move the beam spot of the inspection laser beam within the surface of the optical component 51 (FIG. 1). The light intensity measuring unit 25D acquires the measurement result measured by the light intensity measuring device 20. FIG. The output control unit 25E outputs the measurement result of the light intensity acquired by the light intensity measurement unit 25D to the output device 26 in various forms. An image display device, for example, is used as the output device 26, and the output control unit 25E displays, for example, the measurement result of the light intensity in a graphic form or a graph.

Next, the relative positional relationship between the optical component 51, the processing laser beam 40, and the inspection laser beam 30 will be described with reference to FIG. 3A.

3A is a schematic front view of the optical component 51. FIG. A passing region 41 of the processing laser beam 40 (FIG. 1) is indicated by a dashed line. A deposit 45 adheres to the surface of the optical component 51 and a scratch 46 is generated. A passing region 41 of the processing laser beam 40 is sufficiently large compared to the sizes of the deposits 45 and the scratches 46 . Therefore, the deposits 45 and the scratches 46 do not greatly affect the propagation of the processing laser beam 40 . However, when the number of deposits 45 and scratches 46 increases, the propagation of the processing laser beam 40 is greatly affected, and a situation may arise in which the desired intensity cannot be obtained on the surface of the object 60 .

The beam spot 31 of the inspection laser beam 30 (FIG. 1) is smaller than the passing area 41 of the processing laser beam 40, and is about the same size as the assumed deposit 45 and flaw 46. When the inspection laser beam 30 is scanned by the beam scanner 13 (FIG. 1), the beam spot 31 moves along the movement locus 32 within the surface of the optical component 51 . That is, by repeating main scanning and sub-scanning of the beam spot 31 , almost the entire surface of the optical component 51 is scanned with the beam spot 31 . When the inspection laser beam 30 is a pulsed laser beam, the moving speed of the beam spot 31 may be set so that the beam spots 31 of two laser pulses adjacent on the time axis overlap each other.

The optical path length from the condenser lens 12 (FIG. 1) to the surface of the optical component 51 varies according to the incident position of the inspection laser beam 30 . Therefore, the size of the beam spot 31 (FIG. 3A) of the inspection laser beam 30 on the surface of the optical component 51 also varies depending on the position on the surface. However, even in the state where the beam spot 31 is the largest within the variation range of the size of the beam spot 31, the size is sufficiently smaller than the passing area 41 of the processing laser beam 40, and the expected deposit 45 or It is about the same size as the scratch 46 .

FIG. 3B is a graph showing an example of temporal changes in light intensity measured by the light intensity measuring device 20 (FIG. 1) while the surface of the optical component 51 is being scanned with the inspection laser beam 30. FIG. The horizontal axis represents elapsed time, and the vertical axis represents light intensity. The light intensity decreases at times t1, t2, and t3. The drop in light intensity at times t1 and t2 is caused by the deposit 45, and the drop in light intensity at time t3 is caused by the scratch 46. FIG.

The output control unit 25E of the inspection processing device 25 displays the measurement results of the light intensity measuring device 20 on the output device 26 (FIG. 1) as a time waveform graph as shown in FIG. 3B.

FIG. 4 is a flow chart showing the procedure for inspecting the laser processing apparatus using the inspection apparatus according to this embodiment. First, the moving mechanism control unit 25B (FIG. 2) controls the moving

mechanisms

14 and 21 to move the swing mirror 13B (FIG. 1) and the light intensity measuring device 20 (FIG. 1) from the standby position to the inspection position ( step S1). Next, the laser oscillation control unit 25A (FIG. 2) controls the inspection laser oscillator 11 to output an inspection laser beam, and the beam scanning control unit 25C (FIG. 2) controls the beam scanner 13 to output an inspection laser beam. A laser beam is scanned as shown in FIG. 2A (step S2). Further, the light intensity measuring unit 25D acquires the light intensity measurement result from the light intensity measuring device 20 (step S2).

When the scanning of the surface of the optical component 51 (FIG. 3A) is completed, the output control unit 25E (FIG. 2) outputs the light intensity measurement result to the output device 26 (step S3). After that, or in parallel, the moving mechanism control unit 25B (FIG. 2) controls the moving

mechanisms

14 and 21 to wait the swing mirror 13B (FIG. 1) and the light intensity measuring device 20 (FIG. 1) from the inspection position. Move to position (step S4)

Next, the excellent effects of the above embodiment will be described.
If the deposits 45 and flaws 46 (FIG. 3A) on the surface of the optical component 51 are sufficiently small compared to the passing area 41 (FIG. 3A) of the processing laser beam 40, the processing laser beam 40 for processing when passing through the optical component 51 can be used. The attenuation rate of the light intensity of the laser beam 40 is slight. Therefore, even if the light intensity of the processing laser beam 40 is measured, it is difficult to detect the adhering matter 45 and the flaw 46 .

On the other hand, in the above embodiment, the beam spot 31 (FIG. 3A) of the inspection laser beam 30 is made smaller than the passing area 41 of the processing laser beam 40 . Therefore, even if the adhering matter 45 or the scratch 46 is small, the attenuation rate of the light intensity of the inspection laser beam 30 increases when it passes through the optical component 51 . As a result, the detection sensitivity of small adhering matter 45 and scratches 46 is increased. This makes it possible to detect signs of machining defects before they occur.

As an example, the diameter of the beam spot 31 of the inspection laser beam 30 on the surface of the optical component 51 is 1/ the diameter of the minimum enclosing circle of the passing region 41 (FIG. 3A) of the processing laser beam 40 on the surface of the optical component 51. 10 or less is preferable. This makes it possible to detect the adhering matter 45 and the flaw 46 that are difficult to detect by measuring the attenuation rate of the light intensity of the processing laser beam 40 . In addition, it is preferable to set the diameter of the beam spot 31 of the inspection laser beam 30 on the surface of the optical component 51 to 50 μm or less in view of the size of the assumed deposit 45 and flaw 46 . Conversely, if the beam spot 31 is made too small, the time required for scanning almost the entire surface of the optical component 51 with the inspection laser beam 30 will become longer. Therefore, it is preferable to set the diameter of the beam spot 31 to 5 μm or more.

Next, a preferable wavelength of the inspection laser beam 30 will be described. In order to detect the deposits 45 and scratches 46 (FIG. 3A) of the optical component 51, the transmittance of the optical component 51 is sufficiently high in the wavelength region of the inspection laser beam 30 in the region where the deposits 45 and scratches 46 are not present. is preferred. The optical component 51 is usually coated with an antireflection coating so as to maximize the transmittance in the wavelength range of the processing laser beam 40 . Therefore, it is preferable to make the wavelength of the inspection laser beam 30 substantially the same as the wavelength of the processing laser beam 40 . It should be noted that the wavelength of the inspection laser beam 30 does not necessarily have to be the same as the wavelength of the processing laser beam 40 if a sufficiently high transmittance can be obtained for the inspection laser beam 30 .

Next, a modification of the above embodiment will be described.
In the above-described embodiment, the inspection device is provided for one optical component 51 out of the plurality of optical components that constitute the laser processing apparatus. may be provided. In this case, the inspection processing device 25 and the output device 26 may be shared by a plurality of inspection devices.

In the above embodiment, the inspection laser oscillator 11 is arranged separately from the processing laser oscillator 50, but the laser beam output from the processing laser oscillator 50 may be used as the inspection laser beam. For example, the laser beam output from the processing laser oscillator 50 may be guided to the condenser lens 12 of the inspection optical system 10 via a mirror or the like.

In the above embodiment, the measurement results of the light intensity measuring device 20 (Fig. 1) are displayed on the output device 26 (Fig. 1) in the graph format shown in Fig. 3B. Alternatively, the time waveform graph shown in FIG. 3B may be converted into a two-dimensional light intensity distribution on the surface of the optical component 51 and displayed on the output device 26 as a two-dimensional image. Also, the inspection processing device 25 (FIG. 1) analyzes the waveform of the graph shown in FIG. You may make it

In the above embodiment, the interface (surface) of the optical component 51 that refracts the processing laser beam 40 is inspected, but it is also possible to inspect an optical component that has an interface (surface) that reflects the processing laser beam 40. is. For example, it is possible to inspect the presence or absence of any foreign matter adhering to a reflecting surface such as a plane mirror, a concave mirror, or a convex mirror, or whether there is a scratch or the like on the reflecting surface. In this case, the inspection laser beam 30 scans the opposite surface and measures the intensity of the reflected light from the reflecting surface.

Next, a laser processing apparatus according to another embodiment will be described with reference to FIG. In the following, the description of the configuration common to the laser processing apparatus according to the embodiment shown in FIGS. 1 to 4 will be omitted.

FIG. 5 is a schematic diagram of the laser processing apparatus according to this embodiment. In the embodiment shown in FIG. 1, one swinging mirror 13B of the beam scanner 13 is translated between the inspection position and the standby position. On the other hand, in the embodiment shown in FIG. 5, the pair of oscillating mirrors constituting the beam scanner 13 are not translated, but the movable mirror 15 is translated between the inspection position and the standby position by the moving mechanism 14. move. In FIG. 5, the movable mirror 15 at the inspection position is indicated by a solid line, and the movable mirror 15 at the standby position is indicated by a broken line. The inspection laser beam 30 scanned by the beam scanner 13 is reflected by the moving mirror 15 at the inspection position and enters the optical component 51 to be inspected.

Next, the excellent effects of the embodiment shown in FIG. 5 will be described.
Also in this embodiment, as in the embodiment shown in FIGS. 1 to 4, the deposits 45 and scratches 46 (FIG. 3A) on the optical component 51 can be detected with high sensitivity. Further, in the embodiment shown in FIGS. 1 to 4, the moving mechanism 14 must move the swinging mechanism together with the swinging mirror 13B. In contrast, in this embodiment, since the moving mirror 15 does not swing, the moving mechanism 14 does not need to move the swinging mechanism. Therefore, the moving mechanism 14 can be downsized.

Next, a laser processing apparatus according to still another embodiment will be described with reference to FIG. Hereinafter, explanations of configurations common to the embodiments shown in FIGS. 1 to 4 will be omitted.

FIG. 6 is a schematic diagram of the laser processing apparatus according to this embodiment. In the embodiment shown in FIGS. 1 to 4, the moving mechanism 14 translates some optical components of the inspection optical system 10 between the inspection position and the standby position, and the moving mechanism 21 moves the light intensity measuring device 20. is translated between the inspection position and the standby position. In contrast, in this embodiment, none of the optical components of the inspection optical system 10 is translated. The beam scanner 13 is arranged at a position that does not spatially interfere with the path of the processing laser beam 40 . Any inspection laser beam 30 within the scanning range of the beam scanner 13 is incident on the optical component 51 from an oblique direction.

The light intensity measuring device 20 is arranged at a position where the inspection laser beam 30 that has obliquely entered the optical component 51 and passed through the optical component 51 is incident. The light intensity measuring device 20 also does not translate and is arranged at a position that does not spatially interfere with the path of the processing laser beam 40 .

In this embodiment, the incident angle when the inspection laser beam 30 is incident on the optical component 51 is larger than the incident angle in the laser processing apparatus shown in FIGS. Therefore, the optical path length from the condenser lens 12 to the optical component 51 varies greatly depending on the incident position. Therefore, the variation in the size of the beam spot 31 (FIG. 3A) on the surface of the optical component 51 is increased. Even in the state where the beam spot 31 is the largest within the variation range of the size of the beam spot 31, the size is sufficiently smaller than the passing area 41 of the processing laser beam 40, and the expected deposits 45 and scratches 46 are observed. The optical system such as the condensing lens 12 is adjusted so that the size is about the same.

The interval between scanning lines may be adjusted according to the size of the beam spot 31. For example, in areas where the beam spot 31 is relatively small, the scanning line spacing may be relatively narrow, and in areas where the beam spot 31 is relatively large, the scanning line spacing may be relatively wide.

Next, the excellent effects of the embodiment shown in FIG. 6 will be described.
Also in this embodiment, as in the embodiment shown in FIGS. 1 to 4, the deposits 45 and scratches 46 (FIG. 3A) on the optical component 51 can be detected with high sensitivity. Furthermore, in this embodiment, the inspection device does not need to have a translation mechanism. Therefore, it is possible to reduce the size and cost of the device.

Next, a laser processing apparatus according to still another embodiment will be described with reference to FIG. Hereinafter, the description of the configuration common to the embodiment shown in FIG. 6 will be omitted.

FIG. 7 is a schematic diagram of the laser processing apparatus according to this embodiment. In the embodiment shown in FIG. 6, the beam scanner 13 and the light intensity measuring device 20 are arranged on opposite sides of each other when viewed from the path of the processing laser beam 40 . In contrast, in this embodiment, the beam scanner 13 and the light intensity measuring device 20 are arranged on the same side as viewed from the path of the processing laser beam 40 . A mirror 22 is arranged on the opposite side of the beam scanner 13 as viewed from the path of the processing laser beam 40 . The inspection laser beam 30 that has passed through the optical component 51 is incident on the mirror 22 . The inspection laser beam 30 reflected by the mirror 22 enters the light intensity measuring device 20 .

Next, the excellent effects of the embodiment shown in FIG. 7 will be described.
Also in this embodiment, similarly to the embodiment shown in FIG. 6, the attached matter 45 and the scratch 46 (FIG. 3A) on the optical component 51 can be detected with high sensitivity. The configuration according to this embodiment may be adopted when there is no space for arranging the light intensity measuring device 20 on the opposite side of the beam scanner 13 as viewed from the path of the processing laser beam 40 .

Next, a modification of the embodiment shown in FIG. 7 will be described. Although the mirror 22 used in the laser processing apparatus according to the embodiment shown in FIG. 7 is a plane mirror, a concave mirror may be used instead of the plane mirror. For example, by arranging the beam scanner 13 and the light intensity measuring device 20 at the position of the conjugate point of the concave mirror, the light intensity measuring device 20 with a small light receiving surface can be used.

FIG. 8 is a schematic diagram of the laser processing apparatus according to this embodiment. In the embodiment shown in FIG. 6, the light intensity of the inspection laser beam 30 transmitted through the optical component 51 is measured by the light intensity measuring device 20 . On the other hand, in the embodiment shown in FIG. 8, the light intensity measuring device 20 measures the light intensity of the inspection laser beam 30 reflected by the surface of the optical component 51 .

In the embodiment shown in FIG. 6, as the inspection laser beam 30, a wavelength band in which the transmittance of the optical component 51 coated with antireflection coating with respect to the processing laser beam 40 is sufficiently large is used. On the other hand, in the present embodiment, the inspection laser beam 30 in a wavelength range in which the surface of the optical component 51 has a relatively large reflectance is used.

Next, the excellent effects of the embodiment shown in FIG. 8 will be described.
The reflectance on the surface of the optical component 51 changes due to the deposits 45 and scratches 46 (FIG. 3A) on the surface of the optical component 51 . By measuring the light intensity of the inspection laser beam 30 reflected by the surface of the optical component 51 , it is possible to detect the change in reflectance and detect the presence or absence of the adhering matter 45 and the flaw 46 . It should be noted that the reflectance may be low or high depending on the adhering matter 45 . In either case, the presence or absence of the deposit 45 can be determined by detecting a change in reflectance.

Next, still another embodiment will be described with reference to FIG. Hereinafter, the description of the configuration common to the embodiment shown in FIG. 5 will be omitted.

FIG. 9 is a schematic diagram of the laser processing apparatus according to this embodiment. In the embodiment shown in FIG. 5, one light intensity measuring device 20 is arranged for one inspection optical system 10 . In contrast, in this embodiment, a plurality of light

intensity measuring devices

20A, 20B, 20C, and 20D are arranged for one inspection optical system 10. FIG. A plurality of light

intensity measuring devices

20A, 20B, 20C, and 20D are arranged in this order from the upstream side to the downstream side of the processing laser beam 40 . Each of the plurality of light intensity measuring devices 20A-20D can be translated between an inspection position and a standby position.

A single optical component 51 is arranged between the inspection optical system 10 and the light intensity measuring device 20A. Two

optical components

51 and 54 are arranged between the inspection optical system 10 and the light intensity measuring device 20B. Three

optical components

51, 54 and 55 are arranged between the inspection optical system 10 and the light intensity measuring device 20C. Four

optical components

51, 54, 55 and 56 are arranged between the inspection optical system 10 and the light intensity measuring device 20D.

Also, in the embodiment shown in FIG. 5, the focal length of the condenser lens 12 of the inspection optical system 10 is fixed. In contrast, in this embodiment, a lens with a variable focal length is used as the condenser lens 12 . The focal length of the condenser lens 12 is controlled by the inspection processor 25 .

In the embodiment shown in FIG. 9, two mirrors 59 are arranged to reflect the processing laser beam 40, but the mirrors 59 are not necessarily required, and the number of mirrors is not limited to two. do not have.

The state in which the first light intensity measuring device 20A counted from the upstream side of the processing laser beam 40 is placed at the inspection position is the same as the state in which the light intensity measuring device 20 of the embodiment shown in FIG. 5 is placed at the inspection position. is. In this state, the optical component 51 can be inspected.

In a state where the first light intensity measuring device 20A counted from the upstream side of the processing laser beam 40 is placed at the standby position and the second light intensity measuring device 20B is placed at the inspection position, the inspection laser beam 30 is optically It passes through the

parts

51 and 54 in order and enters the light intensity measuring device 20B. At this time, the inspection processor 25 adjusts the focal length of the condenser lens 12 so that the beam spot is sufficiently small at the position of the second optical component 54 . Furthermore, the inspection processor 25 controls the beam scanner 13 so that the beam spot of the inspection laser beam 30 moves within the surface of the second optical component 54 .

When the first optical component 51 is inspected and no abnormality is confirmed, the second optical component 54 can be inspected with the second light intensity measuring device 20B placed at the inspection position. Similarly, third optical component 55 and fourth optical component 56 can be inspected. At this time, the condenser lens 12 aligns the beam spot of the inspection laser beam 30 at the position of one of the optical components to be inspected selected from the plurality of

optical components

51 , 54 , 55 , 56 so that the processing laser beam 40 passes through. It functions as a focal length adjustment mechanism that makes it smaller than region 41 (FIG. 3A).

Next, the excellent effects of the embodiment shown in FIG. 9 will be described.
In the embodiment shown in FIG. 9, a plurality of

optical components

51, 54, 55 and 56 can be inspected by arranging a plurality of light intensity measuring devices 20A to 20D for one inspection optical system 10. can. Therefore, the number of parts of the inspection apparatus can be reduced compared to a configuration in which the inspection optical system 10 is arranged for each optical part to be inspected.

FIG. 10 is a schematic diagram of the laser processing apparatus according to this embodiment. A beam expander telescope 71, an optical mask 72, a field lens 73, and a beam scanner are arranged in order from the upstream side to the downstream side on the path of the processing laser beam 40 from the processing laser oscillator 50 to the object 60. 75 and an fθ lens 76 are arranged. The beam expander telescope 71 is composed of a plurality of lenses, for example, three lenses, adjusts the size of the beam cross section at the position of the optical mask 72, and converts the processing laser beam into a parallel beam.

The processing laser beam 40 that has passed through the optical mask 72 passes through the field lens 73 and enters the aperture 74 . The aperture 74 shapes the beam profile by passing a predetermined diffracted light of the processing laser beam 40 diffracted by the optical mask 72 .

The beam scanner 75 moves the beam spot of the processing laser beam 40 on the surface of the object 60 by scanning the processing laser beam 40 . The f-theta lens 76 images the opening of the aperture 74 onto the surface of the object 60 .

The object 60 is held on the stage 53. The stage 53 can move the object 60 in two mutually orthogonal directions parallel to its surface. By combining the scanning of the processing laser beam 40 by the beam scanner 75 and the movement of the object 60 by the stage 53 , the processing laser beam 40 can be incident on almost the entire surface of the object 60 .

An inspection optical system 10 and a light intensity measuring device 20 are arranged for each of the plurality of lenses that constitute the beam expander telescope 71 . Furthermore, an inspection optical system 10 and a light intensity measuring device 20 are arranged for each of the field lens 73 and the fθ lens 76 . One inspection processing device 25 and one output device 26 are shared by a plurality of inspection optical systems 10 and a plurality of light intensity measuring devices 20 .

The object 60 is a semiconductor wafer into which dopants are ion-implanted, and the activation annealing of the dopants is performed by a processing laser beam.

Next, the excellent effects of the embodiment shown in FIG. 10 will be described.
In this embodiment, the presence or absence of deposits and scratches on the lens of the beam expander telescope 71, the field lens 73, and the f.theta.

It goes without saying that each of the above-described embodiments is an example, and partial replacement or combination of configurations shown in different embodiments is possible. Similar actions and effects due to similar configurations of multiple embodiments will not be sequentially referred to for each embodiment. Furthermore, the invention is not limited to the embodiments described above. For example, it will be obvious to those skilled in the art that various changes, improvements, combinations, etc. are possible.

10 inspection optical system 11 inspection laser oscillator 12 condenser lens 13

beam scanners

13A and 13B rocking mirror 14 moving mechanism 15 moving

mirrors

20, 20A, 20B, 20C and 20D light intensity measuring device 21 moving mechanism 22 mirror 25 for inspection Processing device 25A Laser oscillation control unit 25B Movement mechanism control unit 25C Beam scanning control unit 25D Light intensity measurement unit 25E Output control unit 26 Output device 30 Inspection laser beam 31 Inspection laser beam beam spot 32 Inspection laser beam beam spot Trajectory 40 Processing laser beam 41 Processing laser beam passage area 45 Attachment 46 Scratches 50

Processing laser oscillators

51, 52 Optical component 53

Stages

54, 55, 56 Optical component 59 Mirror 60 Object 71 Beam expander tele scope 72 optical mask 73 field lens 74 aperture 75 beam scanner 76 fθ lens

Claims

An inspection device for inspecting a laser processing device including at least one optical component having an interface that refracts or reflects a processing laser beam,
The inspection laser beam is incident on the interface of the optical component to be inspected so that the beam spot at the interface of the optical component to be inspected of the laser processing apparatus is smaller than the passing area of the processing laser beam, and an inspection optical system for scanning the beam spot of the inspection laser beam;
and a light intensity measuring device for measuring the light intensity of the inspection laser beam transmitted through or reflected by the interface of the optical component to be inspected.
a moving mechanism for moving one optical component constituting the inspection optical system between a position blocking the path of the processing laser beam and a position not spatially interfering with the path of the processing laser beam; The inspection device according to claim 1, comprising:
The inspection optical system is arranged at a position that does not spatially interfere with the path of the processing laser beam, and the inspection optical system is arranged at an oblique direction with respect to the path of the processing laser beam to the interface of the optical component to be inspected. 2. The inspection apparatus according to claim 1, wherein an inspection laser beam is incident.
The inspection apparatus according to claim 3, wherein the light intensity measuring device is arranged at a position that does not spatially interfere with the path of the processing laser beam.
The laser processing apparatus includes a plurality of optical components having interfaces that refract or reflect the processing laser beam,
The inspection optical system causes the inspection laser beam to enter through a plurality of optical components of the laser processing apparatus,
The light intensity measuring device measures the light intensity of the inspection laser beam that has passed through a plurality of optical components of the laser processing apparatus,
The inspection optical system has a focal length adjustment mechanism that makes the beam spot of the inspection laser beam smaller than the passing area of the processing laser beam at the position of one optical component selected from a plurality of optical components of the laser processing apparatus. The inspection apparatus according to any one of claims 1 to 4, comprising:
An inspection method for inspecting a laser processing apparatus having at least one optical component having an interface that refracts or reflects a processing laser beam,
The beam spot of the inspection laser beam is scanned within the interface under the condition that the beam spot of the inspection laser beam at the interface of the optical component to be inspected of the laser processing apparatus is smaller than the passing area of the processing laser beam. ,
An inspection method for measuring the light intensity of the inspection laser beam transmitted through or reflected by the interface of the optical component to be inspected.
a laser oscillator that outputs a processing laser beam;
at least one optical component disposed on the path of the processing laser beam from the laser oscillator to the object and having an interface that refracts or reflects the processing laser beam;
The inspection laser beam is incident on the interface of the optical component so that the beam spot at the interface of the optical component is smaller than the passing area of the processing laser beam, and the beam spot of the inspection laser beam is scanned within the interface. an inspection optical system for
and a light intensity measuring device for measuring the light intensity of the inspection laser beam transmitted through or reflected by the interface of the optical component.