JP5189472B2 - Laser processing apparatus and optical path adjusting method in laser processing apparatus - Google Patents

Description

  The present invention relates to a laser processing apparatus and an optical path adjustment method in the laser processing apparatus.

  Conventionally, in a microscope laser repair apparatus for correcting a circuit of a fine device such as a semiconductor or a liquid crystal panel, a laser beam emitted from a laser oscillator irradiates a slit opening formed by a slit, and the slit By irradiating the device with laser light transmitted through the opening, only the slit-shaped range can be corrected.

The microscope laser repair device includes, for example, two pairs of slit members that are provided in directions orthogonal to each other and movable in directions that approach and separate from each other, and pass through a slit opening formed by the slit members. There are known a slit width adjusting device and a microscope laser repair device capable of performing device correction of a slit shape by laser light (see, for example, Patent Document 1).
JP 2007-47657 A

By the way, in such a laser repair apparatus, in order to cope with the variety of devices to be corrected, the laser repair apparatus is suitable for the correction from a laser beam having a wide wavelength range covering the ultraviolet region, the visible region, and the infrared region. Generally, laser light having a wavelength is selected and used through a wavelength filter or the like.
Here, since the laser beam used has a deviation in the irradiation direction to the slit depending on its wavelength, the optical path must be adjusted in order to correct the deviation.

  However, for laser light consisting of wavelengths in the ultraviolet and infrared regions, that is, invisible light, the user cannot adjust the optical path while viewing the laser light, so the device is actually irradiated with invisible light. Therefore, the optical path adjustment can only be performed by observing the irradiated device. Therefore, there is a problem that the user's burden is heavy in terms of time and labor in adjusting the optical path for invisible light.

  An object of the present invention is to provide a laser processing apparatus and an optical path adjustment method in the laser processing apparatus that can easily adjust the irradiation direction of the laser light to the slit even if the laser light used for laser processing is invisible light. There is.

In order to solve the above problems, the invention described in claim 1
In a laser processing apparatus that emits laser light and irradiates a sample with laser light that is transmitted through a slit opening formed by a slit provided in an optical path.
A laser oscillator that emits laser light having a plurality of wavelengths including wavelengths in an invisible range;
A wavelength filter for filtering the laser light emitted from the laser oscillator;
Reflecting the laser light filtered by the wavelength filter at a predetermined reflection angle toward the slit, and a reflection angle adjusting mirror capable of adjusting the reflection angle;
A visualization unit that is arranged in the optical path and visualizes a position at which the laser beam in an invisible region having a predetermined wavelength irradiates the slit among the laser beams reflected by the reflection angle adjusting mirror,
It is characterized by providing.

  According to a second aspect of the present invention, there is provided the laser processing apparatus according to the first aspect, wherein an adjustment unit including the wavelength filter and the reflection angle adjusting mirror as a set is adjusted in accordance with a wavelength of laser light to be filtered by the wavelength filter. A plurality of sets are provided, and a unit switching selection unit configured so that any one of the plurality of sets is arranged in the optical path is provided.

  A third aspect of the present invention is the laser processing apparatus according to the first or second aspect, wherein the visualization unit includes a reflector that reflects visible light when irradiated with laser light having a wavelength in an invisible range. It is characterized by being configured.

  According to a fourth aspect of the present invention, in the laser processing apparatus according to any one of the first to third aspects, the visualization unit is detachably provided at a position where the slit is provided.

  According to a fifth aspect of the present invention, in the optical path adjustment method in the laser processing apparatus according to the second aspect, an adjustment unit that filters laser light having a desired wavelength among the plurality of sets of adjustment units in the unit switching selection unit. In the optical path, a step of arranging a visualization unit for visualizing the laser light of the desired wavelength in the optical path, a step of emitting laser light by the laser oscillator, and the reflection angle adjusting mirror An adjustment step of adjusting the reflection angle.

According to the present invention, in a laser processing apparatus, laser light having a plurality of wavelengths including invisible wavelengths is emitted from a laser oscillator, filtered by a wavelength filter, and the filtered laser light is reflected by a reflection angle adjusting mirror. And the position where the laser beam in an invisible region irradiates the slit in the laser beam can be visualized by the visualization unit arranged in the optical path.
Therefore, the user can easily correct the deviation of the irradiation direction of the laser beam on the slit by adjusting the reflection angle of the reflection angle adjusting mirror after visually observing the position where the laser beam irradiates the slit.
Therefore, even if the laser beam used for laser processing is invisible light, it can be said that this invention is a laser processing apparatus which can adjust easily the irradiation direction to the slit of the said laser beam.

  Hereinafter, specific embodiments of the laser processing apparatus according to the present invention will be described in detail with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

FIG. 1 shows a schematic configuration of a laser processing apparatus 1 according to the present invention, in which (A) is a front view, (B) is a side view, and FIG. 2 is a reflection in the laser processing apparatus 1 according to the present invention. It is a figure explaining the structure of angle adjustment mirror 33a-33d, (A) is a XZ top view, (B) is a YZ top view, FIG. 3 is the laser oscillator 10 in the laser processing apparatus 1 which concerns on this invention. It is a schematic block diagram which shows the optical path of the laser beam radiate | emitted from, and the target 42, (A) is a YZ top view, (B) is a YX top view.
In the following description, the left-right direction of the laser processing apparatus 1 is the X-axis direction, the front-rear direction is the Y-axis direction, and the up-down direction is the Z-axis direction.

  As shown in FIG. 1, the laser processing apparatus 1 is a microscope laser repair apparatus that corrects defects or the like generated in a sample (device) by irradiating laser light, and emits laser light in the Y-axis direction. Laser oscillator 10, a beam expander 20 for expanding the diameter of the laser light emitted from laser oscillator 10, and the laser light transmitted through beam expander 20 are filtered, and the filtered laser light in the Y-axis direction Unit selector 30 for reflecting the laser beam in the Z-axis direction, slit portion 40 for limiting the reach of the laser beam reflected by the unit selector 30 to the sample, and adjusting the XY direction of the slit 40 A rotary table 45, an imaging lens 50 and an objective lens unit 60 that form an image of laser light on the sample, and a sample or a sample slip placed on a stage (not shown). An observation unit 70 for observing the working range, is configured to include a like.

The laser oscillator 10 includes a laser beam (invisible light) having a wavelength (fundamental wavelength) of 1064 (nm), a laser beam (visible light) having a wavelength of 532 (nm), and 355 (nm). ) Laser light (invisible light) as a third harmonic having a wavelength of) and laser light (invisible light) as a fourth harmonic having a wavelength of 266 (nm) are used as a beam expander. This is a laser light source emitting toward 20.
The laser oscillator 10 may emit laser light having a wide wavelength range from the ultraviolet region to the infrared region, and may be configured to simultaneously emit the laser beams having the four different wavelengths. It may be what you did.

  The beam expander 20 enlarges the diameter of the laser light output from the laser oscillator 10 and emits the laser light having the enlarged diameter toward the unit switching selection unit 30.

  For example, as shown in FIG. 1A, the unit switching selection unit 30 is formed in a circular shape in the XZ plan view, and four adjustment units 31a, 31b, 31c and 31d are provided, and are configured to rotate 90 degrees about the Y-axis direction as a central axis. Therefore, by rotating the unit switching selection unit 30 to 0 degrees, 90 degrees, 180 degrees, and 270 degrees, any one of the four adjustment units 31a to 31d (31a in FIG. 1) is placed in the optical path. Can be arranged. That is, the user can use the unit switching selection unit 30 to place an adjustment unit for filtering laser light having a desired wavelength in the optical path.

  The adjustment units 31a, 31b, 31c, and 31d are configured to include wavelength filters 32a, 32b, 32c, and 32d, and reflection angle adjustment mirrors 33a, 33b, 33c, and 33d, respectively.

  Each of the wavelength filters 32 a to 32 d is a filter that filters laser light having a predetermined wavelength from the laser light transmitted through the beam expander 20. As an example, in the present embodiment, the wavelength filter 32a is a laser beam having a wavelength of 1064 (nm), the wavelength filter 32b is a laser beam having a wavelength of 532 (nm), and the wavelength filter 32c is 355 (nm). The laser light having a wavelength is a filter in which the wavelength filter 32d filters the laser light having a wavelength of 266 (nm).

The reflection angle adjusting mirrors 33a to 33d reflect the laser light filtered by the wavelength filters 32a to 32d toward the slit portion 40 (Z-axis (downward) direction), respectively.
Further, as shown in FIGS. 2A and 2B, the reflection angle adjusting mirrors 33a to 33d are fixed to the mirror fixing members 36a to 36d, respectively, and the back surfaces (XZ surface) of the mirror fixing members 36a to 36d. ) And the main body portion 30a of the unit switching selection unit 30, the three screw members 34a to 34d arranged concentrically pass through, and both are arranged at the same position as the screw members 34a to 34d. It is connected to the three spring members 35a-35d.
Therefore, the user adjusts the reflection angle by inclining the mirror fixing members 36a to 36d to a desired angle by the advance and retreat of the three screw members 34a to 34d and the elastic deformation of the three spring members 35a to 35d. The mirrors 33a to 33d can be adjusted to the desired angle.

  The slit portion 40 (slit) includes a fixed portion 41 (visualization portion) and slit members 44a, 44b, 44c, and 44d.

  The fixing unit 41 includes a target 42 (reflecting plate) and a fixing member 43.

  For example, the target 42 is a sheet coated with a powdered luminescent material based on the property that when a laser beam having a wavelength in an invisible region is incident on the luminescent material, visible light is emitted according to the shape and intensity of the laser beam. It is a card-type sensor that functions as a reflector that is attached to a part of the sheet, makes laser light having a wavelength in an invisible range incident on the sheet, and converts the laser light into visible light to be reflected. Since this card type sensor has different sensitivities depending on the wavelength range of the incident laser beam, the card type sensor that is successively optimized (can exhibit high sensitivity) according to the wavelength of the laser beam filtered by the wavelength filters 32a to 32d. Select a sensor.

Further, the target 42 is marked with a mark 42a at a predetermined reference position as shown in FIGS. Here, the predetermined reference position is a position where the laser light filtered by the wavelength filters 32a to 32d should pass in order to accurately irradiate a slit opening formed by slit members 44a to 44d described later.
That is, by arranging an optimal card type sensor as the target 42 in the optical path, the laser light filtered by the wavelength filters 32a to 32d is filtered by invisible light (any of the wavelength filters 32a, 32c, 32d). Visible light can be emitted by the target 42. Therefore, for example, the user visually observes the position where the filtered laser beam shown in FIG. 3A is reflected from the mark 42a on the target 42 (that is, the position where the slit is irradiated). B) can be grasped as the light emission position 42b, and the deviation between the position and the position where the mark 42a is attached can be confirmed. The user can easily correct the deviation by adjusting the angles of the reflection angle adjusting mirrors 33a to 33d.

  The target 42 is detachably attached to the fixing member 43. When performing laser processing on the sample, the target 42 is removed and the condenser lens is fixed by the fixing member 43. Then, the laser beam reflected by any one of the reflection angle adjustment mirrors 33a to 33d is condensed on the slit opening. Therefore, the target 42 is formed in a disk shape having the same diameter as the condensing lens in order to facilitate attachment / detachment by the fixing member 43.

  The fixing member 43 is, for example, a lens holder for fixing and supporting the side surface of the target 42 (or the condensing lens).

The slit members 44a and 44b are formed in a rectangular plate shape in plan view, and the tip portions facing each other are formed in a tapered blade shape. The slit members 44a and 44b are applied with a driving force by a stepping motor or the like (not shown) and move in the X-axis direction so as to approach and separate from each other, so that an arbitrary gap can be formed in the X-axis direction. It becomes.
The slit members 44c and 44d are provided below the slit members 44a and 44b, are formed in a rectangular plate shape in plan view, and tip portions facing each other are formed in a tapered blade shape. The slit members 44c and 44d are applied with a driving force by a stepping motor or the like (not shown) and move in the Y-axis direction so as to approach and separate from each other, so that an arbitrary gap can be formed in the Y-axis direction. It becomes.
Therefore, it is possible to adjust the processing range of the sample by restricting only the gaps (slit openings) formed by the slit members 44a to 44d so that the laser light is transmitted.

  The rotary table 45 is a table on which the slit portion 40 is placed, and is rotatable about the Z-axis direction when a driving force is applied by a rotation stepping motor or the like. Therefore, by rotating the rotary table 45, the direction of the gap formed by the slit members 44a and 44b of the slit portion 40 and the direction of the gap formed by the slit members 44c and 44d are accurately determined in the X and Y axis directions. Can be adjusted to match.

  The imaging lens 50 forms an image of the laser beam that has passed through the slit opening of the slit unit 40 and the rotary table 45, and irradiates the sample with the laser beam in combination with an objective lens unit 60 described later.

The objective lens unit 60 includes a plurality of objective lenses having different magnifications provided in each wavelength region (ultraviolet region, near ultraviolet region, visible light region, near infrared region), and the plurality of objective lenses in the X-axis direction. For example, an objective lens switching unit 61 that is driven linearly in the X-axis direction by applying a driving force by a motor or the like, and the like. Then, according to the type and size of the sample to be processed, the objective lens switching unit 61 is moved by a predetermined amount in the X-axis direction, and the objective lens is adjusted to the wavelength range and magnification of the laser light filtered by the unit switching selection unit 30. The sample is switched to a suitable lens (for example, the objective lens 62) and arranged in the optical path so that the sample can be irradiated with slit-shaped laser light.
The objective lens switching unit 61 is equipped with a plurality of objective lenses having different magnifications for each wavelength region, and according to the type of the adjustment units 31a to 31d arranged in the optical path (that is, the laser beam to be filtered). Depending on the wavelength, it may be controlled to automatically switch to an objective lens having an appropriate wavelength range and magnification.

  The observation unit 70 includes a slit illumination light source 72 and a half mirror for reflecting light in the X-axis (left) direction emitted from the slit illumination light source 72 toward the optical path direction (Z-axis (down) direction). 72a, an epi-illumination light source 73, and a half mirror 73a for reflecting light in the X-axis (left) direction emitted from the epi-illumination light source 73 toward the optical path direction (Z-axis (down) direction) A CCD camera for observation 74, a CCD camera for autofocus 76, a half mirror 74a for obtaining reflected light for observation, a tube lens 74b, a mirror 74c, a beam splitter 74d, and the like. The

The slit illumination light source 72 emits illumination light in a direction intersecting the optical path (for example, the X-axis (left) direction), and this illumination light is transmitted in the optical path direction (Z-axis (downward) by a half mirror 72a provided on the optical path. ) Direction), transmitted through the slit opening of the slit 40, and irradiated on the sample through the imaging lens 50 and the objective lens unit 60.
The epi-illumination light source 73 emits illumination light in a direction intersecting the optical path (for example, the X-axis (left) direction), and this illumination light is transmitted along the optical path direction (Z-axis (lower) by a half mirror 73a provided on the optical path. ) Direction), and the sample is irradiated through the imaging lens 50 and the objective lens unit 60.

The observation CCD camera 74 and the autofocus CCD camera 76 receive the illumination light of the epi-illumination light source 73 or the slit illumination light source 72 reflected from the sample, and project the range where the slit processing is performed on the sample and the sample. And focus adjustment respectively.
In other words, the illumination light of the epi-illumination light source 73 or the slit illumination light source 72 reflected from the sample passes through the objective lens 62 of the objective lens unit 60 to become parallel light, and crosses the optical path in the half mirror 74a (X Reflected in the axis (right) direction. The reflected light forms an intermediate image of the parallel light by the tube lens 74b, is reflected by the mirror 74c in a direction parallel to the optical path (Z-axis (upward) direction), and is linearly transmitted by the beam splitter 74d. Are separated into light reflected in a direction intersecting the optical path (X-axis (right) direction) and received by the observation CCD camera 74 and the autofocus CCD camera 76, respectively.
Therefore, by receiving the reflected light of the illumination light applied to the sample from the slit illumination light source 72 and the epi-illumination light source 73, the user can observe the CCD camera while being focused by the autofocus CCD camera 76. Through 74, it is possible to accurately observe the sample and the range of laser processing on the sample.
Therefore, it is possible to adjust the laser processing range by the slit portion 40 and the rotary table 45 in advance while visually recognizing with the observation CCD camera 74.

  Next, a method for adjusting the optical path of the laser light emitted from the laser oscillator 10 according to the present embodiment will be described with reference to the process flowchart of FIG.

First, the user arranges any one of adjustment units 31a to 31d for filtering laser light having a desired wavelength in the optical path by rotating the unit switching selection unit 30 (step S1).
Next, the user fixes the optimum target 42 corresponding to the wavelength of the laser light filtered by the adjustment unit arranged in step S1 to the fixing member 43 and arranges it in the optical path (step S2).
Of course, the processing in step S1 may be performed after the processing in step S2. That is, a predetermined target 42 is selected and fixed to the fixing member 43, the unit switching selection unit 30 is rotated, and any one of the adjustment units 31a to 31d corresponding to the target 42 is arranged in the optical path. The process to do is also possible.

  Next, the user emits laser light from the laser oscillator 10 (step S3), and generates reflected light by the target 42, thereby irradiating the target 42 with the laser light filtered by the adjustment unit arranged in step S1. The position is confirmed (step S4).

Next, the user confirms the deviation between the irradiation position of the laser beam and the position of the mark 42a as the reference position (step S5).
And when a user judges that there exists the said shift (step S5; Yes), the reflection angle of the reflection angle adjustment mirrors 33a-33d is adjusted (step S6), and the process after step S3 is repeated.
On the other hand, when the user determines that there is no deviation (step S5; No), the present process is terminated, and the condenser lens is fixed to the fixing member 43 in place of the target 42, thereby accurately processing the sample. The process can be executed.

As described above, in the laser processing apparatus 1 according to the present invention, laser light having a plurality of wavelengths including wavelengths in the invisible region is emitted from the laser oscillator 10, and any one of the wavelength filters 32a to 32d among the laser light. Laser light having a predetermined wavelength is filtered, and the filtered laser light is reflected by the reflection angle adjusting mirrors 33a to 33d to irradiate the target 42 disposed in the optical path, and the target 42 emits visible light. By doing so, the position where the laser beam irradiates the slit can be visualized.
Therefore, the user can easily correct the deviation of the irradiation direction of the laser light to the slit by adjusting the reflection angles of the reflection angle adjusting mirrors 33a to 33d while viewing the position.
Therefore, even if the laser beam used for laser processing is invisible light, it can be said that this invention is a laser processing apparatus which can adjust easily the irradiation direction to the slit of the said laser beam.

Further, the laser processing apparatus 1 includes a unit switching selection unit 30 including adjustment units 31a to 31d each including wavelength filters 32a to 32d and reflection angle adjustment mirrors 33a to 33d. Is configured such that any one of the adjustment units 31a to 31d is arranged in the optical path.
Therefore, the user can sequentially filter laser light having a desired wavelength and adjust the optical path of the laser light in accordance with the type of sample to be laser processed by the laser processing apparatus 1 and the processing content. Become.

Moreover, the target 42 in the laser processing apparatus 1 uses a card-type sensor having a property as a reflecting plate that converts a laser beam having a wavelength in an invisible range into a visible beam and reflects the laser beam. Yes.
Therefore, the user can easily visualize laser light having a wavelength in the visible range by simply selecting an optimal card type sensor sequentially according to the wavelength of the laser light filtered by the wavelength filters 32a to 32d. Become.

Further, the target 42 is detachably attached to the fixing member 43.
Therefore, when the adjustment of the reflection angle by the reflection angle adjustment mirrors 33a to 33d is finished and the laser processing is performed on the sample, the target 42 is removed, and the condenser lens is fixed by the fixing member 43, so that the laser beam is obtained. Can be focused on the slit opening, and laser processing can be performed on the sample with the laser light transmitted through the slit opening.

In the above-described embodiment, the arrangement position of the visualization unit is the fixed part 41. However, the position is not limited to this position. For example, the visualization part may be arranged above the fixed part 41 in the optical path. good.
In the unit switching selection unit 30, when the laser light filtered by the wavelength filters 32a to 32d is visible light (laser light filtered by the wavelength filter 32b), the target 42 is the card type sensor. There is no need, and it is sufficient if it has a diffusion surface such as plain paper.
In addition, the objective lens switching unit 61 according to the present invention is not limited as long as it has a plurality of objective lenses and can switch and arrange a predetermined objective lens in the optical path, and may be, for example, a rotary revolver or the like. .

BRIEF DESCRIPTION OF THE DRAWINGS The schematic structure of the laser processing apparatus which concerns on this invention is shown, (A) is a front view, (B) is a side view. It is a figure explaining the structure of the reflection angle adjustment mirror in the laser processing apparatus which concerns on this invention, (A) is a XZ top view, (B) is a YZ top view. In the laser processing apparatus according to the present invention, it is a schematic configuration diagram showing an optical path and a target of laser light emitted from a laser oscillator, (A) is a YZ plan view, and (B) is a YX plan view. It is a process flowchart explaining the optical path adjustment method in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Laser processing apparatus 10 Laser oscillator 30 Unit switching selection part 31a-31d Adjustment unit 32a-32d Wavelength filter 33a-33d Reflection angle adjustment mirror 40 Slit part (slit)
41 Fixed part (visualization part)
42 Target (Reflector)

Claims (5)

In a laser processing apparatus that emits laser light and irradiates a sample with laser light that is transmitted through a slit opening formed by a slit provided in an optical path.
A laser oscillator that emits laser light having a plurality of wavelengths including wavelengths in an invisible range;
A wavelength filter for filtering the laser light emitted from the laser oscillator;
Reflecting the laser light filtered by the wavelength filter at a predetermined reflection angle toward the slit, and a reflection angle adjusting mirror capable of adjusting the reflection angle;
A visualization unit that is arranged in the optical path and visualizes a position at which the laser beam in an invisible region having a predetermined wavelength irradiates the slit among the laser beams reflected by the reflection angle adjusting mirror,
A laser processing apparatus comprising: In the laser processing apparatus of Claim 1,
A plurality of adjustment units each including a set of the wavelength filter and the reflection angle adjustment mirror are provided in accordance with the wavelength of the laser light filtered by the wavelength filter, and any one of the plurality of adjustment units is provided in the optical path. A laser processing apparatus comprising: a unit switching selection unit configured to be arranged in In the laser processing apparatus according to claim 1 or 2,
The laser processing apparatus, wherein the visualization unit includes a reflector that reflects visible light when irradiated with laser light having a wavelength in an invisible region. In the laser processing apparatus as described in any one of Claims 1-3,
The laser processing apparatus, wherein the visualization unit is detachably provided at a position where the slit is provided. In the laser beam path adjustment method in the laser processing device according to claim 2,
Arranging in the optical path an adjustment unit that filters laser light having a desired wavelength among the plurality of sets of adjustment units in the unit switching selection unit;
Arranging a visualization part in the optical path for visualizing the laser beam of the desired wavelength;
Emitting laser light by the laser oscillator;
An adjustment step of adjusting the reflection angle by the reflection angle adjustment mirror;
An optical path adjusting method in a laser processing apparatus comprising:

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