Substrate suspension type laser processing device and suspension height measurement method

Abstract

The present invention relates to a substrate suspension type laser processing device and a method for measuring the suspension height. The substrate suspension type laser processing device according to an embodiment includes: a stage for suspending and transporting a substrate; and a suspension height measuring device for measuring the suspension height H of the substrate. Note that the distance between the suspension height measuring device and the substrate can be automatically adjusted according to the measured suspension height H. The suspension height H of the substrate is measured by applying laser to the substrate and the stage. The distance between the suspension height measuring device and the substrate is adjusted by using a feedback mechanism in which the measured suspension height of the substrate is used as an input.

Description

Technical Field

[0001] The invention relates to a substrate suspension type laser processing device and a suspension height measurement method. Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2018-064048 discloses a laser processing device that irradiates a substrate including an amorphous film formed on a glass substrate or the like with laser light and performs an annealing process on the substrate. In the laser processing device disclosed in Japanese Unexamined Patent Application Publication No. 2018-064048, the annealing process is performed on a suspension stage on which the substrate is suspended by jetted air. Summary of the invention

[0003] Regarding the levitation stage for levitating a substrate, it is necessary to accurately control the levitation of the substrate in order to apply the laser to a desired position. Therefore, it is necessary to accurately measure the levitation height of the substrate. However, the levitation height has not yet been measured with satisfactory accuracy, so there is room for improvement in the measurement.

[0004] Other problems to be solved and novel features will become readily understood from the description of the present invention and the accompanying drawings.

[0005] The first exemplary aspect is a substrate levitation type laser processing apparatus, comprising: a stage configured to levitation and transport a substrate; and a levitation height measuring device for measuring the levitation height of the substrate. Note that the distance between the levitation height measuring device and the substrate can be automatically adjusted according to the measured levitation height.

[0006] According to an embodiment, a substrate suspension type laser processing device and a suspension height measurement method can be provided, which can improve the performance of laser processing by suppressing the generation of dust or the like caused by the contact between the substrate and the stage, and can accurately control the irradiation position of the laser.

[0007] The above and other objects, features and advantages of the present disclosure will become more fully understood from the detailed description given below and the accompanying drawings, which are given by way of illustration only and thus should not be construed as limiting the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 A perspective schematic diagram of the structure of a substrate floating type laser processing device according to an example of the first embodiment;

[0009] Figure 2 A schematic plan view of a stage of a substrate floating type laser processing apparatus according to an example of the first embodiment;

[0010] Figure 3 Shown from Figure 2 The substrate floating type laser processing device of the first embodiment as viewed at the section line III-III shown;

[0011] Figure 4 An example of the levitation height measured by the levitation height measuring device in the substrate levitation type laser processing apparatus according to the first embodiment is shown;

[0012] Figure 5 An example of a levitation height measuring device for a substrate levitation type laser processing device of a comparative example is shown;

[0013] Figure 6 is a structural diagram of an example of a levitation height measuring device and a controller in a substrate levitation type laser processing device according to the first embodiment;

[0014] Figure 7 is a flowchart of an example of a method for measuring the levitation height of a substrate using the substrate levitation type laser processing apparatus of the first embodiment;

[0015] Figure 8 is a perspective view schematically showing an example of a method for measuring the levitation height of a stationary substrate in the substrate levitation type laser processing apparatus according to the first embodiment;

[0016] Fig. 9 is a perspective view schematically showing an example of a method for measuring the floating height of a moving substrate in the substrate floating type laser processing apparatus according to the first embodiment;

[0017] Fig.10 An example of a measurement operation of the levitation height of a substrate performed by the levitation height measuring device in the substrate levitation type laser processing device according to the second embodiment is schematically shown;

[0018] Fig.11 An example of a measurement operation of the levitation height of a substrate performed by the levitation height measuring device in the substrate levitation type laser processing device according to the second embodiment is schematically shown;

[0019] Fig.12 An example of a measurement operation of the levitation height of a substrate performed by the levitation height measuring device in the substrate levitation type laser processing device according to the third embodiment is schematically shown;

[0020] Fig.13 An example of a measurement operation of the levitation height of a substrate by the levitation height measurement device in the substrate levitation type laser processing apparatus according to the third embodiment is schematically shown. DETAILED DESCRIPTION

[0021] In order to make the description clear, the following description and drawings have been partially omitted and appropriately simplified. In addition, in all the drawings, the same symbols are assigned to the same or corresponding components, and redundant descriptions are appropriately omitted.

[0022] (First Embodiment)

[0023] A substrate suspension type laser processing device according to a first embodiment will be described. The substrate suspension type laser processing device according to this embodiment is, for example, an excimer laser annealing device for forming a polysilicon film. Note that the substrate suspension type laser processing device is not limited to an excimer laser annealing device as long as the device performs laser processing while suspending the substrate 50. The substrate suspension type laser processing device according to this embodiment includes a suspension height measuring device that measures the suspension height of the substrate. For example, after assembling (i.e., manufacturing) the substrate suspension type laser processing device or when setting conditions before performing laser processing, the suspension height of the substrate is measured by using the suspension height measuring device.

[0024] First, each component / structure of the substrate levitation type laser processing device will be described below. Among the components / structures, the levitation height measurement device according to the present embodiment will be described while being compared with the levitation height measurement device according to the comparative example, and problems occurring in the levitation height measurement device according to the comparative example will be explained. In this way, the substrate levitation type laser processing device according to the present embodiment is more clearly understood.

[0025] Figure 1 It is a perspective schematic diagram of the structure of a substrate floating type laser processing apparatus according to an example of the first embodiment. Figure 2 The figure is a schematic plan view of a stage of a substrate floating type laser processing apparatus according to an example of the first embodiment. Figure 3 Shown from Figure 2 The substrate floating type laser processing apparatus according to the first embodiment is shown as viewed along the section line III-III.

[0026] like Figure 1-3 As shown, the substrate levitation type laser processing apparatus 1 includes a stage 10, a laser emitting unit 20, a levitation height measuring device 30, and a controller 40. Roughly speaking, in the substrate levitation type laser processing apparatus 1, while the substrate 50 is levitation and transferred above the stage 10, the laser emitting unit 20 performs laser processing on the substrate 50.

[0027] Note that for the sake of explanation, an XYZ orthogonal coordinate system is appropriately used in the drawings described below. Among them, the Z-axis direction is a vertical upward / downward direction, and the Y-axis direction is a direction along the linear laser spot emitted by the laser emitting unit 20. In addition, the X-axis direction is a direction in which the substrate 50 is transported. While the substrate 50 is transported in the X-axis direction, a linear laser extending in the Y-axis direction is applied to the substrate 50. In addition, the X-axis direction and the Y-axis direction are directions along the side of the substrate 50 having a rectangular shape.

[0028] Each component / structure of the substrate levitation type laser processing apparatus 1 will be described below.

[0029] <Stand>

[0030] The stage 10 suspends and transports the substrate 50. The stage 10 has a top surface facing upward. The top surface of the stage 10 is referred to as a stage surface 10a. When viewed from above, the stage surface 10a has, for example, a rectangular shape, and its side faces extend in the X-axis and Y-axis directions. The stage 10 includes a plurality of suspension units 11. Note that Figure 1-3 In the drawings, reference numerals are added only to some of the suspension units 11 to simplify the drawings. In addition, some components / structures may be omitted.

[0031] Each suspension unit 11 has a top surface facing upward. The top surface of the suspension unit 11 is called a unit surface 11a. When viewed from above, each unit surface 11a has, for example, a rectangular shape, with side surfaces extending in the X-axis and Y-axis directions. The stage surface 10a includes a plurality of unit surfaces 11a. For example, the plurality of unit surfaces 11a are arranged in a matrix in the X-axis direction and the Y-axis direction within the stage surface 10a. Therefore, the stage surface 10a is composed of a plurality of unit surfaces 11a arranged in a matrix.

[0032] The suspension unit 11 sprays air upward to suspend the substrate 50. For example, a plurality of air spray holes (not shown) are formed on the unit surface 11a of the suspension unit 11, and the substrate 50 is suspended by the air sprayed from the air spray holes. Note that in the suspension unit 11, air may be sprayed from a porous material provided at an upper portion thereof, instead of using the air spray holes.

[0033] An air jetting pipe (not shown) is connected below the levitation unit 11. The air jetting pipe is connected to a pump, for example, via a valve and an air flow meter. The valve and the air flow meter are connected to the controller 40 via a signal line or the like. The levitation height of the substrate 50 on the stage surface 10a is controlled by controlling the valve and the pump using the controller 40.

[0034] The stage 10 may be equipped with a gripping mechanism (not shown) for conveying the substrate 50. On the stage 10, the substrate 50 may be conveyed by gripping the ends of the substrate 50 with the gripping mechanism, or may be conveyed by gripping the center portion of the substrate 50 with the gripping mechanism.

[0035] <Substrate>

[0036] The substrate 50 is, for example, a glass substrate. The substrate 50 may be a semiconductor substrate such as a silicon substrate. The substrate 50 may include a semiconductor film. The semiconductor film is made of, for example, amorphous silicon. The purpose of the laser treatment may be to convert the semiconductor film in the substrate 50 into a polycrystalline state, into a single crystalline state, to reform the semiconductor film, to inactivate impurities, or to stabilize impurities. For example, by irradiating at least a portion of the amorphous semiconductor film with laser light, it is converted into a polycrystalline state. Note that the laser treatment is not limited to the above purposes. The laser treatment may include any kind of treatment for heat-treating the substrate 50 by irradiating the substrate 50 with laser light. In addition, the substrate 50 is not limited to a glass substrate and a semiconductor substrate, as long as the substrate is subjected to laser treatment.

[0037] <Laser emission unit>

[0038] The laser emitting unit 20 emits laser light. For example, the laser emitting unit 20 applies excimer laser light to the substrate 50. Note that the laser light emitted from the laser emitting unit 20 is not limited to the excimer laser light. That is, the laser emitting unit 20 may emit any kind of laser light suitable for the desired laser processing. The irradiation point 21 of the laser light applied to the substrate 50 by the laser emitting unit 20 has a linear shape extending in the Y-axis direction, for example.

[0039] <Suspension height measurement device: Suspension height>

[0040] Figure 4 An example of the levitation height measured by the levitation height measuring device in the substrate levitation type laser processing apparatus of the first embodiment is shown. Figure 4 As shown, the levitation height measuring device 30 measures the levitation height H of the substrate 50. The levitation height H of the substrate 50 refers to the distance from the stage surface 10a to the bottom surface 50b of the substrate 50. The distance from the levitation height measuring device 30 to the top surface 50a of the substrate 50 is referred to as the distance L1, and the distance from the levitation height measuring device 30 to the bottom surface 50b of the substrate 50 is referred to as the distance L2. In addition, the distance from the levitation height measuring device 30 to the stage surface 10a (i.e., the unit surface 11a) is referred to as the distance L3. Then, the levitation height H of the substrate 50 is expressed as "levitation height H = distance L3 - distance L2".

[0041] <Suspension height measurement device: laser displacement meter>

[0042] The levitation height measuring device 30 includes, for example, a laser displacement meter 31 and a height adjustment stage 32. The laser displacement meter 31 applies laser to the substrate 50 and the stage 10, and receives reflected light of the laser reflected by the substrate 50 and the stage 10. The laser displacement meter 31 simultaneously measures (e.g., calculates) the distance L1, the distance L2, and the distance L3 based on the difference between the reflectivity of the reflected light of the laser reflected by the top surface 50a of the substrate 50 and the reflectivity of the reflected light reflected by the bottom surface 50b of the substrate 50, and the reflectivity of the reflected light reflected by the stage surface 10a. In this way, the laser displacement meter 31 can measure the levitation height H. As described above, the levitation height H of the substrate 50 is measured by applying laser to the substrate 50.

[0043] The height adjustment stage 32 is mounted on the laser displacement meter 31. The height adjustment stage 32 can adjust the position of the laser displacement meter 31 in the Z-axis direction, that is, the height of the laser displacement meter 31. A measurement range R in which the distances L1, L2, and L3 can be measured is set in the laser displacement meter 31. When the distances L1, L2, and L3 exceed the measurement range, the levitation height H of the substrate 50 cannot be accurately measured. Therefore, the height adjustment stage 32 adjusts the height of the laser displacement meter 31 so that the distances L1, L2, and L3 fall within the measurement range. Note that the levitation height measuring device 30 is not limited to a device equipped with a laser displacement meter 31 described later.

[0044] The levitation height measuring device 30 may include a translational motion stage 33. The translational motion stage 33 is a rod-shaped movable stage extending in the Y-axis direction on a horizontal plane above the stage 10. The laser displacement meter 31 is mounted on the translational motion stage 33 so that the height adjustment stage 32 is provided. Therefore, the laser displacement meter 31 and the height adjustment stage 32 can slide and move in the Y-axis direction along the translational motion stage 33. In this way, the levitation height measuring device 30 measures the levitation height H of the substrate 50 along the Y-axis direction.

[0045] The levitation height measuring device 30 may include a translational motion stage 34. In particular, two translational motion stages 34 are arranged to sandwich the stage 10 in the Y-axis direction. One of the translational motion stages 34 is arranged to extend in the X-axis direction along the side of the stage 10 in the positive direction of the Y-axis direction, and the other translational motion stage 34 is arranged to extend in the X-axis direction along the side of the stage 10 in the negative direction of the Y-axis direction. A frame 35 extending upward is attached to each of the translational motion stages 34 in such a manner that the frame 35 is slidable in the X-axis direction. The frame 35 of one of the translational motion stages 34 supports one end of the translational motion stage 33, and the frame 35 of the other translational motion stage 34 supports the other end of the translational motion stage 33. Therefore, the translational motion stage 33 can move in the X-axis direction. In this way, the levitation height measuring device 30 measures the levitation height H of the substrate 50 along the X-axis and Y-axis directions.

[0046] <Comparative Example: Suspension Height Measurement Device>

[0047] Next, a levitation height measuring device of a substrate levitation type laser processing device according to a comparative example will be described. Figure 5 An example of a levitation height measuring device for a substrate levitation type laser processing device of a comparative example is shown. Figure 5 As shown, the levitation height measuring device 130 according to the comparative example further includes a laser displacement meter 131, a height adjustment stage 132, and a translational motion stage 33. The stage 10 and the laser emitting unit 20 of the substrate levitation type laser processing device 101 of the comparative example are similar to the stage 10 and the laser emitting unit 20 of the substrate levitation type laser processing device 1 according to the first embodiment.

[0048] Similar to the laser displacement meter 31, the laser displacement meter 131 also applies laser to the substrate 50 and the stage 10, and receives the reflected light of the laser reflected by the substrate 50 and the stage 10. The laser displacement meter 131 simultaneously measures (e.g., calculates) the distance L1, the distance L2, and the distance L3 based on the difference between the reflectivity of the reflected light of the laser reflected by the top surface 50a of the substrate 50 and the reflectivity of the reflected light reflected by the bottom surface 50b of the substrate 50 and the reflectivity of the reflected light reflected by the stage surface 10a. In this way, the laser displacement meter 131 can measure the levitation height H. When the levitation height measuring device 130 measures the levitation height of the substrate 50 by using the laser displacement meter 131, it measures the levitation height while moving the measurement position by using the translation motion stage 33. A measurement range in which the distances L1, L2, and L3 can be measured is set in the laser displacement meter 131. When the distances L1, L2, and L3 exceed the measurement range, the laser displacement meter 131 cannot accurately measure the levitation height of the substrate.

[0049] like Figure 5 As shown, the stage surface 10a is composed of a plurality of unit surfaces 11a. The positions of the plurality of unit surfaces 11a may be offset from each other in the Z-axis direction. Therefore, in the case where the suspension unit 11 and the stage 10 have no planar relationship with each other over the entire stage surface 10a, when the laser displacement meter 131 is moved, the distances L1, L2, and L3 may exceed the measurement range R. Therefore, the suspension height of the substrate 50 cannot be accurately measured.

[0050] As described above, the substrate levitation type laser processing apparatus 101 according to the comparative example has a problem in that, when the levitation height of the substrate 50 is measured by using the laser displacement meter 131, the distances L1, L2, and L3 may exceed the measurement range R as the laser displacement meter 131 is moved because the stage surface 10a is not flat over its entire area. In this case, it is necessary to adjust the height of the laser displacement meter 131 by manually moving the height adjustment stage 132 so that the distances L1, L2, and L3 fall within the measurement range R.

[0051] <According to an embodiment of the present invention: Suspension height measuring device and controller control>

[0052] Next, a levitation height measuring device in the substrate levitation type laser processing device 1 according to the present embodiment will be described. Figure 6 FIG. 1 is a structural diagram of an example of a levitation height measuring device and a controller in a substrate levitation type laser processing device according to the first embodiment. Figure 6 As shown, the levitation height measuring device 30 according to the present embodiment is connected to a controller 40. The levitation height measuring device 30 includes a laser displacement meter 31 and a height adjustment stage 32. The controller 40 includes, for example, a laser displacement meter controller 41, a stage controller 42, and a servo amplifier 43.

[0053] The laser displacement meter controller 41 is connected to the laser displacement meter 31, for example, via a wired signal line such as an optical fiber or a wireless signal line. The laser displacement meter controller 41 is connected to the stage controller 42 via a signal line or the like. The stage controller 42 is connected to the servo amplifier 43 via a signal line or the like. The servo amplifier 43 is connected to the height adjustment stage 32 via a signal line or the like.

[0054] The laser displacement meter controller 41 receives height information including the distances L1, L2, and L3 and the levitation height H measured (e.g., calculated) based on these distances by the laser displacement meter 31 through a signal line or the like. The laser displacement meter controller 41 transmits the received height information to the stage controller 42. The height information may be, for example, an analog signal.

[0055] Height information including the measured levitation height H is input from the levitation height measuring device 30 to the stage controller 42. The stage controller 42 adjusts the distance between the levitation height measuring device 30 and the substrate 50 based on a preset target value and the input levitation height H.

[0056] Specifically, the stage controller 42 compares the input levitation height H with the preset target value G. Then, when the difference Δ (Δ=HG) between the input levitation height H and the set target value G is negative (i.e., less than zero), the stage controller 42 outputs the height command value of the Z axis to the servo amplifier 43 so that the levitation height H is greater than the target value G. The height command value may be an analog signal or a pulse signal. On the other hand, when the difference Δ (Δ=HG) between the input levitation height H and the set target value G is positive (i.e., greater than zero), the stage controller 42 outputs the height command value of the Z axis to the servo amplifier 43 so that the levitation height H is less than the target value G. In this way, the distance between the levitation height measuring device 30 and the substrate 50 is automatically adjusted.

[0057] The stage controller 42 may include a storage unit in which the input distances L1, L2, and L3 and the measured levitation height H are stored. In addition, when the difference between the target value and the input levitation height H exceeds a predetermined range, the stage controller 42 excludes the input levitation height H from the data for adjusting the distance. For example, a singular point on the stage surface 10a, such as a gap between the levitation unit 11 and an air injection hole in the levitation unit 11, is excluded from the adjustment data.

[0058] The servo amplifier 43 receives the height command value of the Z axis of the height adjustment stage 32 from the stage controller 42. At the same time, the servo amplifier 43 acquires information about the height at which the laser displacement meter 31 is located from the height adjustment stage 32. For example, the servo amplifier 43 acquires the height value on the Z axis at which the laser displacement meter 31 is located from an encoder provided in the height adjustment stage 32. Then, the servo amplifier 43 moves the height adjustment stage 32 until the height information acquired from the height adjustment stage 32 reaches the height command value received from the stage controller 42.

[0059] Even when the positions of the plurality of unit surfaces 11 a are offset from each other in the Z-axis direction and the levitation unit 11 and the stage 10 have no planar relationship with each other over the entire stage surface 10 a, the controller 40 adjusts the height of the laser displacement meter 131 so that the distances L1, L2, and L3 fall within the measurement range R. Therefore, the distances L1, L2, and L3 do not exceed the measurement range R. In this way, the levitation height 50 of the substrate can be accurately measured.

[0060] As described above, in the substrate levitation type laser processing device 1 according to the present embodiment, the distance between the levitation height measuring device 30 and the substrate 50 can be automatically adjusted according to the measured levitation height H by feedback control. The levitation height H of the substrate 50 is measured, for example, by irradiating laser light to the substrate 50 and the stage 10. Then, the distance between the levitation height measuring device 30 and the substrate 50 is adjusted by using a feedback mechanism using the measured levitation height of the substrate 50 as an input. In this way, the measured distances L1, L2, and L3 can be prevented from exceeding the measurement range R.

[0061] <Method for measuring substrate floating height>

[0062] Next, a method for measuring the levitation height of the substrate 50 will be described. Figure 7 This is a flowchart of an example of a method of measuring the floating height of a substrate using the substrate floating type laser processing apparatus according to the first embodiment.

[0063] like Figure 7 As shown in step S11 in FIG. 1 , first, the levitation height H at a predetermined position on the substrate 50 is measured by using the levitation height measuring device 30. The levitation height measuring device 30 includes, for example, a laser displacement meter 31. The levitation height H of the substrate 50 is measured by applying laser light to the substrate 50 and the stage 10. The predetermined position on the substrate 50 may be any position on the substrate 50. For example, the predetermined position may be a position on the substrate 50 located above the levitation unit 11, which is at the end of the substrate 50 on the positive side of the Y axis. For example, the laser displacement meter 31 simultaneously measures (e.g., calculates) the distance L1, the distance L2, and the distance L3 based on the difference between the reflectivity of the reflected light of the laser reflected by the top surface 50a of the substrate 50 and the reflectivity of the reflected light reflected by the bottom surface 50b of the substrate 50 and the reflectivity of the reflected light reflected by the stage surface 10a. In this way, the levitation height measuring device 30 measures (i.e., calculates) the levitation height H (levitation height H=distance L3-distance L2). Note that the levitation height measuring devices 30 are not limited to those equipped with the laser displacement meter 31 .

[0064] Next, as shown in step S12, the distance between the levitation height measuring device 30 and the substrate 50 is automatically adjusted according to the measured levitation height H. The controller 40, to which the levitation height H from the levitation height measuring device 30 is input, adjusts the distance between the levitation height measuring device 30 and the substrate 50 based on the preset target value and the input levitation height H. In this way, the substrate levitation type laser processing device 1 according to the present embodiment adjusts the distance between the levitation height measuring device 30 and the substrate 50 by using a feedback mechanism in which the measured levitation height of the substrate 50 is used as an input.

[0065] Next, as shown in step S13, it is determined whether the measurement of the levitation height H of the substrate has been completed. In the case of "yes", that is, the measurement has been completed, the process ends. In the case of "no", that is, when the measurement has not been completed, as shown in step S14, the levitation height measurement device 30 is moved so that a different position on the substrate 50 can be measured. For example, the laser displacement meter 31 is moved by using the translational motion stage 33. In this way, a position on the substrate 50 different from the predetermined position is measured. Alternatively, the substrate 50 can be moved by the gripping unit of the stage 10 so that a different position on the substrate 50 can be measured.

[0066] Next, the process returns to step S11, and the levitation height H of the substrate 50 is measured by using the levitation height measuring device 30. In addition, steps S11 to S14 are repeated until the measurement is finished. Therefore, for the measurement of the levitation height at each measurement position on the substrate 50, the distance between the levitation height measuring device 30 and the substrate 50 is adjusted. Therefore, at each measurement position, the distances L1, L2, and L3 are adjusted so that they approach and follow the target value within the measurement range R. In this way, the levitation height of the substrate 50 at each measurement position can be accurately measured. In this way, the levitation height of the substrate 50 is measured.

[0067] <Method for measuring the floating height of a stationary substrate>

[0068] As an example of a method for measuring the levitation height H of the substrate 50, a method for measuring the levitation height H of a stationary substrate 50 will be described. The term "stationary" refers to a case where the levitation height H of the substrate 50 is measured without transporting the substrate 50. Figure 8 This is a perspective view schematically showing an example of a method for measuring the floating height of a stationary substrate in the substrate floating type laser processing apparatus according to the first embodiment.

[0069] like Figure 8 As shown, when the levitation height H of the substrate 50 is statically measured without conveying the substrate 50, the levitation height H of the substrate 50 is measured while the levitation height measuring device 30 is moved by the translational motion stages 33 and 34. Then, the levitation height H of the substrate 50 over the entire stage surface 10a is measured by changing the position of the substrate 50 set on the stage surface 10a. In this way, a portion where the levitation height between the stage 10 and the substrate 50 is smaller than that of other portions and a portion where the stage 10 and the substrate 50 contact each other can be found in advance. Therefore, the generation of dust and the like due to the contact between the substrate 50 and the stage 10 can be suppressed.

[0070] <Method for measuring the floating height of the moving substrate>

[0071] Next, as an example of a method for measuring the levitation height H of the substrate 50, a method for measuring the levitation height H of the moving substrate 50 will be described. The term "moving" refers to a case where the levitation height H of the substrate 50 is measured while the substrate 50 is conveyed. Fig. 9 This is a perspective view schematically showing an example of a method for measuring the floating height of a movable substrate in the substrate floating type laser processing apparatus according to the first embodiment.

[0072] like Fig. 9 As shown, when the floating height H of the substrate 50 is dynamically measured while the substrate 50 is transported, the floating height H of the substrate 50 is measured while the substrate 50 is transported by using the gripping unit of the stage 10. For example, when measuring the floating height H of the substrate 50 disposed above the stage 10 below the laser emitting unit 20, a method for measuring the floating height H of the moving substrate 50 is important. When the substrate 50 is transported to a position below the laser emitting unit 20, the substrate 50 may be tilted upward or warped. As a result, the focus of the laser is shifted, and thus the desired laser may not be applied to the substrate 50. Therefore, by measuring the floating height H of the moving substrate 50 below the laser emitting unit 20 in advance, the irradiation position of the laser can be accurately measured. In this way, the performance of the laser processing can be improved.

[0073] Hereinafter, the effect of the present embodiment will be described. In the substrate suspension type laser processing device 1 according to the present embodiment, the distance between the suspension height measuring device 30 and the substrate 50 can be automatically adjusted. That is, by feeding back the output of the laser displacement meter 31 to control the height, even when the measurement position of the laser displacement meter 31 moves, the distances L2 and L3 automatically fall within the measurement range R of the laser displacement meter 31. Therefore, it is possible to prevent the measured distances L1, L2, and L3 from exceeding the measurement range R of the suspension height measuring device 30. For example, the distances L1, L2, and L3 are made to follow the target values ​​within the measurement range R, thereby automatically adjusting the distance between the suspension height measuring device 30 and the substrate 50. Therefore, since the distances L1, L2, and L3 do not exceed the measurement range, the suspension height of the substrate 50 can be accurately measured.

[0074] Furthermore, since the floating height H of the substrate 50 is measured over the entire stage surface 10a, it is possible to find in advance a portion where the floating height between the stage 10 and the substrate 50 is smaller than other portions, and a portion where the stage 10 and the substrate 50 are in contact with each other. In this way, generation of dust or the like due to contact between the substrate 50 and the stage 10 can be suppressed.

[0075] Furthermore, the irradiation position of the laser light can be accurately measured by measuring the floating height H of the moving substrate 50 located below the laser emitting unit 20. In this way, the performance of the laser processing can be improved.

[0076] The levitation height H of the substrate 50 is measured by applying laser light to the substrate 50 and the stage 10. Therefore, accurate measurement can be performed using the wavelength of the laser light.

[0077] Note that although the case where the distance between the levitation height measuring device 30 and the substrate 50 is adjusted by using a feedback mechanism is described above, the user may manually adjust the height adjustment stage 32 so that the distances L1 to L3 fall within the measurement range R. Furthermore, the case where the height of the levitation unit 11 side is adjusted so that the distances L1 to L3 fall within the measurement range R is not excluded.

[0078] In addition, the distance between the levitation height measuring device 30 and the stage surface 10a may be measured in advance and stored in a storage unit. That is, the controller 40 includes a storage unit in which the distance between the levitation height measuring device 30 and the stage surface 10a is stored in advance. Then, in order to keep the height of the laser displacement meter 31 constant regardless of where the laser displacement meter 31 moves on the XY plane, by using the distance between the levitation height measuring device 30 and the stage surface 10a stored in the storage unit, the controller 40 automatically adjusts the distance between the levitation height measuring device 30 and the substrate 50 so that the distances L1 to L3 fall within the measurement range R. Therefore, since the distances L1 to L3 do not exceed the measurement range R, the levitation height of the substrate 50 can be accurately measured.

[0079] (Second Embodiment)

[0080] Hereinafter, a substrate levitation type laser irradiation device according to a second embodiment will be described. In this embodiment, the levitation height measurement device includes a camera. Fig.10 and Fig.11 An example of a measurement operation of the floating height of a substrate by the floating height measuring device in the substrate floating type laser processing apparatus according to the second embodiment is schematically shown.

[0081] like Fig.10 and Fig.11 As shown, the suspension height measuring device 60 of the substrate suspension type laser processing device 2 according to the present embodiment includes a camera 61 and a height adjustment stand 62. The camera 61 captures an image of the top surface 50a of the substrate 50. The height adjustment stand 62 is mounted on the camera 61. The height adjustment stand 62 can adjust the position of the focus of the camera 61 in the Z-axis direction, that is, the height of the focus of the camera 61. The measurement range in which the camera 61 can adjust its focus is set in the camera 61. When the position of the focus exceeds the measurement range, the suspension height H of the substrate 50 cannot be accurately measured. Therefore, the height adjustment stand 32 adjusts the height of the camera 61 so that its focus falls within the measurement range.

[0082] When the levitation height H of the substrate 50 is measured by using the camera 61, the levitation height H is measured by adjusting the position of the focus of the camera 61 focused on the top surface 50a of the substrate 50 before and after the substrate 50 is levitated. Fig.10 As shown, the substrate 50 is lowered to the suspension unit 11 by stopping the jet of air in the suspension unit 11 (step A). ​​Then, by adjusting the height of the camera 61 using the height adjustment stage 62, the height of the camera 61 whose focus coincides with the top surface 50a of the substrate 50 is found (step B).

[0083] Next, if Fig.11 As shown, the substrate 50 is suspended by ejecting air in the suspension unit 11 (step C). Then, by adjusting the height of the camera 61 using the height adjustment stage 62, the height of the camera 61 whose focus coincides with the top surface 50a of the substrate 50 is found again (step D). Next, the difference between the height found in step B and the height found in step D is measured (e.g., calculated) as the suspension height H.

[0084] As described above, in this embodiment, the camera 61 can measure the suspension height H of the substrate 50 based on the position where the focus of the camera 61 coincides with the top surface 50a of the substrate 50 when the substrate 50 is in contact with the stage 10, and the position where the focus of the camera 61 coincides with the top surface 50a of the substrate 50 when the substrate 50 is suspended on the stage 10.

[0085] Note that when the camera 61 can capture an image of the bottom surface 50 b of the substrate 50 and the stage surface 10 a through the substrate 50 (e.g., in a fluoroscope manner), the camera 61 can measure the levitation height H of the substrate 50 based on the position where the focus of the camera 61 coincides with the top surface 50 a or the bottom surface 50 b of the substrate 50 and the position where the focus of the camera 61 coincides with the stage surface 10 a. Specifically, the difference between the height where the focus of the camera 61 coincides with the top surface 50 a or the bottom surface 50 b of the substrate 50 and the height where the focus of the camera 61 coincides with the stage surface 10 a can be measured (i.e., calculated) as the levitation height H. Note that when the focus is adjusted to the top surface 50 a of the substrate 50, the levitation height is obtained by subtracting the thickness of the substrate 50 from the difference between the heights.

[0086] According to the substrate levitation type laser processing device 2 of the present embodiment, the levitation height measuring device 60 uses the camera 61. In addition, since the levitation height H of the substrate 50 can be measured based on the position of the focus of the camera 61, the levitation height H can be easily measured. The remaining configuration and effects are described in the description of the first embodiment above.

[0087] (Third Embodiment)

[0088] Hereinafter, a substrate levitation type laser processing apparatus according to a third embodiment will be described. In this embodiment, the levitation height measuring device includes a length measuring device. Fig.12 and Fig.13 An example of a measurement operation of the floating height of a substrate by the floating height measuring device in the substrate floating type laser processing apparatus according to the third embodiment is schematically shown.

[0089] like Fig.12 and Fig.13 As shown, the levitation height measuring device 70 of the substrate levitation type laser processing device 3 according to the present embodiment includes a length measuring device 71. The length measuring device 71 measures the distance to the top surface 50a of the substrate 50. The length measuring device 71 is, for example, a contact length measuring device, an ultrasonic displacement sensor, or a linear proximity sensor. The contact length measuring device is, for example, a pick tester, a digital gauge, etc., and it contacts the top surface 50a of the substrate 50 to measure the distance to the top surface 50a of the substrate 50. The ultrasonic displacement sensor applies ultrasonic waves to the substrate 50, and measures (e.g., calculates) the distance to the top surface 50a of the substrate 50 from the reflected waves of the ultrasonic waves reflected by the top surface 50a of the substrate 50. The linear proximity sensor measures the distance to the top surface 50a of the substrate 50 by using a metal plate disposed above the top surface 50a of the substrate 50.

[0090] When the floating height H of the substrate 50 is measured by using the length measuring device 71, the following steps are performed. Fig.12 As shown, the substrate 50 is lowered to the suspension unit 11 by stopping the jetting of air in the suspension unit 11 (step A). ​​Then, the length measuring device 71 is arranged on the top surface 50a of the substrate 50 (step B).

[0091] Next, if Fig.13 As shown, the substrate 50 is suspended by ejecting air in the suspension unit 11 (step C). Then, the length of displacement of the length measuring device 71 when the substrate 50 is suspended is measured (step D). The suspension height H can be measured based on the length of displacement of the length measuring device 71.

[0092] As described above, in this embodiment, the length measuring device 71 is able to measure the suspension height H of the substrate 50 based on the distance from the substrate 50 to the top surface 50a of the substrate 50 when the substrate 50 is in contact with the stage 10, and the distance from the substrate 50 to the top surface 50a of the substrate 50 when the substrate 50 is suspended above the stage 10.

[0093] According to the substrate levitation type laser processing device 3 of the present embodiment, the levitation height measuring device 70 uses the length measuring device 71. By using the length measuring device 71, the distance to the top surface 50a of the substrate 50 can be accurately measured. The remaining configurations and effects are described in the description of the first and second embodiments above.

[0094] The present invention made by the inventors of the present application has been described in detail above based on the embodiments. However, the present invention is not limited to the above embodiments, and needless to say, various modifications and changes can be made without departing from the spirit and scope of the present invention.

[0095] A person skilled in the art can combine the first to third embodiments as needed.

[0096] From the disclosure thus described, it will be apparent that the embodiments of the present disclosure may be modified in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present disclosure, and all such modifications obvious to those skilled in the art are intended to be included within the scope of the appended claims.

Claims

1. A substrate suspension type laser processing device, characterized in that: include: a stage for suspending and transporting the substrate; a levitation height measuring device, used to measure the levitation height of the substrate, wherein the levitation height is the distance from the surface of the stage to the bottom surface of the substrate; and a controller, to which the levitation height is input from the levitation height measuring device, the controller being configured to determine a difference between the measured levitation height and a preset target value, wherein a distance along a vertical axis between the levitation height measuring device and the substrate can be automatically adjusted by moving the levitation height measuring device along the vertical axis based on the determined difference, The distance between the levitation height measuring device and the substrate is adjusted so that: when the difference is negative, the levitation height is greater than the target value, and when the difference is positive, the levitation height is less than the target value.

2. The substrate suspension type laser processing device according to claim 1, characterized in that: The levitation height of the substrate is measured by applying laser to the substrate and the stage.

3. The substrate suspension type laser processing device according to claim 1, characterized in that: The distance between the flying height measurement device and the substrate is adjusted by using a feedback mechanism that takes the measured flying height of the substrate as input.

4. The substrate suspension type laser processing device according to claim 2, characterized in that: The levitation height measuring device includes a laser displacement meter for applying laser to the substrate and the stage and receiving reflected light of the laser reflected by the substrate and the stage, and The laser displacement meter measures the levitation height of the substrate based on reflected light of the laser reflected by a bottom surface of the substrate and reflected light of the laser reflected by a top surface of the stage.

5. The substrate suspension type laser processing device according to claim 1, characterized in that: The levitation height measuring device includes a camera for capturing an image of the top surface of the substrate, and The camera measures the levitation height of the substrate based on a position where a focus of the camera coincides with the top surface of the substrate when the substrate is in contact with the stage, and a position where a focus of the camera coincides with the top surface of the substrate when the substrate is suspended above the stage.

6. The substrate suspension type laser processing device according to claim 1, characterized in that: The levitation height measuring device includes a camera for capturing an image of the top surface of the substrate, and The camera measures the levitation height of the substrate based on a position where a focus of the camera coincides with the top surface or bottom surface of the substrate and a position where a focus of the camera coincides with a top surface of the stage.

7. The substrate suspension type laser processing device according to claim 1, characterized in that: The levitation height measuring device includes a length measuring device for measuring the distance to the top surface of the substrate, and The length measuring device measures the levitation height of the substrate based on a distance to the top surface of the substrate when the substrate is in contact with the stage and a distance to the top surface of the substrate when the substrate is levitated above the stage.

8. The substrate suspension type laser processing device according to claim 1, characterized in that: The suspension height measuring device includes a translational motion stage extending in one direction on a horizontal plane above the stage, and The levitation height measuring device measures the levitation height of the substrate along the one direction.

9. The substrate suspension type laser processing device according to claim 8, characterized in that: The translational motion stage is movable in another direction perpendicular to the one direction on the horizontal plane above the stage.

10. The substrate suspension type laser processing device according to claim 1, characterized in that: The stage includes a plurality of suspension units for spraying air to suspend the substrate, and The top surface of the stage includes top surfaces of the plurality of suspension units.

11. The substrate suspension type laser processing device according to claim 1, characterized in that: When the difference between the target value and the input levitation height exceeds a predetermined range, the controller excludes the input levitation height from data used for adjusting the distance.

12. The substrate suspension type laser processing device according to claim 1, characterized in that: The controller includes a storage unit in which the distance between the levitation height measuring device and the stage is stored, and The controller corrects the measured levitation height of the substrate by using the distance stored in the storage unit.

13. A method for measuring the suspension height of a substrate, characterized in that: The following steps are involved: Measuring the levitation height of the substrate by using a levitation height measuring device, the levitation height measuring device being used to measure the levitation height of the substrate placed above a stage, the stage being used to suspend and transport the substrate, wherein the levitation height is the distance from the surface of the stage to the bottom surface of the substrate; and Using a controller, the levitation height is inputted from the levitation height measuring device to the controller, and the controller is used to determine the difference between the measured levitation height and a preset target value, automatically adjusting the distance between the levitation height measurement device and the substrate along the vertical axis by moving the levitation height measurement device along the vertical axis based on the determined difference, The distance between the levitation height measuring device and the substrate is adjusted so that: when the difference is negative, the levitation height is greater than the target value, and when the difference is positive, the levitation height is less than the target value.

14. The method for measuring the levitation height according to claim 13, characterized in that: In the step of measuring the levitation height of the substrate, the levitation height of the substrate is measured by applying laser to the substrate and the stage.

15. The method for measuring the levitation height according to claim 13, characterized in that: In the step of automatically adjusting the distance, the distance between the levitation height measuring device and the substrate is adjusted by using a feedback mechanism that inputs the measured levitation height of the substrate.

16. The method for measuring the levitation height according to claim 14, characterized in that: The levitation height measuring device includes a laser displacement meter for applying the laser to the substrate and the stage and receiving reflected light of the laser reflected by the substrate and the stage, and In the step of measuring the levitation height of the substrate, the laser displacement meter measures the levitation height of the substrate by reflected light of the laser reflected by the bottom surface of the substrate and reflected light of the laser reflected by the top surface of the stage.

17. The method for measuring the levitation height according to claim 13, characterized in that: The levitation height measuring device includes a camera for capturing an image of the top surface of the substrate, and In the step of measuring the floating height of the substrate, the camera measures the floating height of the substrate based on the position where the focus of the camera coincides with the top surface of the substrate when the substrate is in contact with the stage, and the position where the focus of the camera coincides with the top surface of the substrate when the substrate is suspended above the stage.

18. The method for measuring the levitation height according to claim 13, characterized in that: The levitation height measuring device includes a camera for capturing an image of the top surface of the substrate, and In the step of measuring the levitation height of the substrate, the camera measures the levitation height of the substrate based on a position where the focus of the camera coincides with the top surface or bottom surface of the substrate and a position where the focus of the camera coincides with the top surface of the stage.

19. The method for measuring the levitation height according to claim 13, characterized in that: The levitation height measuring device includes a length measuring device for measuring the distance to the top surface of the substrate, and In the step of measuring the levitation height of the substrate, the length measuring device measures the levitation height of the substrate based on a distance to the top surface of the substrate when the substrate is in contact with the stage and a distance to the top surface of the substrate when the substrate is suspended above the stage.

20. The method for measuring the levitation height according to claim 13, characterized in that: The suspension height measuring device includes a translational motion stage extending in one direction on a horizontal plane above the stage, and In the step of measuring the levitation height of the substrate, the levitation height measuring device measures the levitation height of the substrate along the one direction.

21. The method for measuring the levitation height according to claim 20, characterized in that: In the step of measuring the levitation height of the substrate, the translational motion stage is movable in another direction perpendicular to the one direction on the horizontal plane above the stage.

22. The method for measuring the levitation height according to claim 13, characterized in that: The stage includes a plurality of suspension units for spraying air to suspend the substrate, and The top surface of the stage includes top surfaces of the plurality of suspension units.

23. The method for measuring the levitation height according to claim 13, characterized in that: In the step of automatically adjusting the distance, when the difference between the target value and the input levitation height exceeds a predetermined range, the controller excludes the input levitation height from data for adjusting the distance.

24. The method for measuring the levitation height according to claim 13, characterized in that: The controller further includes a storage unit in which the distance between the levitation height measuring device and the stage is stored, and In the step of automatically adjusting the distance, the controller corrects the measured levitation height of the substrate by using the distance stored in the storage unit.

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