Substrate floating type laser processing apparatus and method for measuring floating height

Abstract

To provide a substrate levitation type laser processing device and a levitation amount measurement method that can improve the performance of laser processing.SOLUTION: A substrate levitation type laser processing device 1 according to an embodiment includes a stage 10 that levitates and transports a substrate 50 and a levitation amount measurement device 30 that measures the levitation amount H of the substrate 50. Here, a distance between the levitation amount measurement device 30 and the substrate 50 can be automatically adjusted according to the measured levitation amount H. The levitation amount H of the substrate 50 is measured by irradiating the substrate 50 and the stage 10 with a laser beam. The distance between the levitation amount measurement device 30 and the substrate 50 is adjusted by using a feedback mechanism for inputting the measured levitation amount of the substrate 50.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a substrate floating type laser processing apparatus and a method for measuring a floating amount. [Background technology]

[0002] Patent Document 1 discloses a laser processing apparatus that performs an annealing process by irradiating a substrate including an amorphous film formed on a glass substrate, etc. with a laser beam. The laser processing apparatus of Patent Document 1 performs the annealing process on a floating stage that floats the substrate by ejecting air. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-064048 A Summary of the Invention [Problem to be solved by the invention]

[0004] The levitation stage that levitates the substrate is required to accurately control the levitation of the substrate in order to irradiate the desired position with laser light. Therefore, it is necessary to measure the levitation amount of the substrate with high accuracy, but this is not sufficient and there is room for improvement.

[0005] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0006] A substrate floating type laser processing apparatus according to one embodiment includes a stage for floating and transporting a substrate, and a floating height measuring device for measuring the floating height of the substrate, and the distance between the floating height measuring device and the substrate can be automatically adjusted according to the measured floating height. Effect of the Invention

[0007] According to the embodiment, it is possible to provide a substrate floating type laser processing apparatus and a method for measuring the floating amount, which can improve the performance of laser processing by suppressing the generation of dust and the like due to contact between the substrate and the stage and controlling the irradiation position of the laser light with high precision. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view illustrating a schematic configuration of a substrate floating type laser processing apparatus according to a first embodiment. [Diagram 2] 1 is a plan view illustrating a schematic example of a stage of the substrate floating type laser processing apparatus according to the first embodiment. [Diagram 3] 3 is a view of the substrate floating type laser processing apparatus according to the first embodiment as viewed from III-III in FIG. 2. [Figure 4] 4 is a diagram illustrating an example of a flying height measured by a flying height measuring device in the substrate flying type laser processing apparatus according to the first embodiment. FIG. [Diagram 5] FIG. 13 is a diagram illustrating a flying height measuring device of a substrate flying type laser processing apparatus according to a comparative example. [Figure 6] 2 is a configuration diagram illustrating a flying height measuring device and a controller in the substrate flying type laser processing apparatus according to the first embodiment. FIG. [Figure 7] 4 is a flow chart illustrating a method for measuring the floating amount of a substrate using the substrate floating type laser processing apparatus according to the first embodiment. FIG. [Figure 8] 1 is a perspective view showing a schematic example of a method for measuring a static floating amount of a substrate in a substrate floating type laser processing apparatus according to the first embodiment. FIG. [Figure 9] 1 is a perspective view showing a schematic example of a method for measuring a dynamic floating amount of a substrate in a substrate floating type laser processing apparatus according to the first embodiment. FIG. [Figure 10] 10 is a diagram illustrating a schematic example of an operation of a flying height measuring device measuring the flying height of a substrate in a substrate flying type laser processing apparatus according to the second embodiment. FIG. [Figure 11]10 is a diagram illustrating a schematic example of an operation of a flying height measuring device measuring the flying height of a substrate in a substrate flying type laser processing apparatus according to the second embodiment. FIG. [Figure 12] 13A and 13B are diagrams illustrating an example of an operation of a flying height measuring device measuring the flying height of a substrate in a substrate flying type laser processing apparatus according to a third embodiment. [Figure 13] 13A and 13B are diagrams illustrating an example of an operation of a flying height measuring device measuring the flying height of a substrate in a substrate flying type laser processing apparatus according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] For clarity of explanation, the following description and drawings are omitted and simplified as appropriate. In addition, in each drawing, the same elements are given the same reference numerals, and duplicate explanations are omitted as necessary.

[0010] (Embodiment 1) A substrate floating type laser processing apparatus according to a first embodiment will be described. The substrate floating type laser processing apparatus according to this embodiment is, for example, an excimer laser annealing apparatus for forming a polysilicon film. The substrate floating type laser processing apparatus is not limited to an excimer laser annealing apparatus as long as it is an apparatus for floating the substrate 50 and performing laser processing. The substrate floating type laser processing apparatus of this embodiment is provided with a floating amount measuring device for measuring the floating amount of the substrate. For example, after assembling the substrate floating type laser processing apparatus or when setting conditions before laser processing, the floating amount of the substrate is measured using the floating amount measuring device.

[0011] First, each component of the substrate floating type laser processing device will be described below. Among the components, the floating height measuring device will be compared with a comparative example, and the floating height measuring device of this embodiment will be described while explaining the problems of the comparative example. This will make the substrate floating type laser processing device of this embodiment clearer.

[0012] Fig. 1 is a perspective view showing a schematic configuration of a substrate floating type laser processing apparatus according to embodiment 1. Fig. 2 is a plan view showing a schematic stage of the substrate floating type laser processing apparatus according to embodiment 1. Fig. 3 is a view of the substrate floating type laser processing apparatus according to embodiment 1 as seen from III-III in Fig. 2.

[0013] 1 to 3, the substrate floating type laser processing apparatus 1 includes a stage 10, a laser irradiation unit 20, a floating height measuring device 30, and a controller 40. Roughly speaking, the substrate floating type laser processing apparatus 1 floats and transports a substrate 50 on the stage 10, and performs laser processing on the substrate 50 in the laser irradiation unit 20.

[0014] In the drawings shown below, for convenience of explanation, an XYZ Cartesian coordinate system is used as appropriate. The Z-axis direction is the vertical direction, the Y-axis direction is the direction along the linear laser spot irradiated by the laser irradiation unit 20, and the X-axis direction is the conveying direction of the substrate 50. While the substrate 50 is conveyed in the X-axis direction, a linear laser beam along the Y-axis direction is irradiated onto the substrate 50. The X-axis and Y-axis directions are also directions along the edge sides of the rectangular substrate 50.

[0015] Each component of the substrate floating type laser processing apparatus 1 of this embodiment will be described below.

[0016] <Stage> The stage 10 levitates and transports the substrate 50. The stage 10 has an upper surface facing upward. The upper surface of the stage 10 is called the stage surface 10a. When viewed from above, the stage surface 10a is, for example, a rectangle with its edges aligned in the X-axis direction and the Y-axis direction. The stage 10 has a plurality of levitation units 11. Note that in Figs. 1 to 3, only some of the levitation units 11 are labeled with reference numerals in order to avoid cluttering the drawings. Also, some components may be omitted.

[0017] The levitation unit 11 has an upper surface facing upward. The upper surface of the levitation unit 11 is called a unit surface 11a. When viewed from above, each unit surface 11a is, for example, a rectangle with its edges aligned in the X-axis direction and the Y-axis direction. The stage surface 10a includes a plurality of unit surfaces 11a. For example, the plurality of unit surfaces 11a are arranged in a matrix on the stage surface 10a in the X-axis direction and the Y-axis direction. Thus, the stage surface 10a is composed of a plurality of unit surfaces 11a arranged in a matrix.

[0018] The levitation unit 11 ejects air upward to levitate the substrate 50. For example, a plurality of air ejection holes (not shown) are provided on the unit surface 11a of the levitation unit 11, and the air ejected from the air ejection holes levitates the substrate 50. Note that the levitation unit 11 may eject air from a porous portion provided on the upper portion instead of the air ejection holes.

[0019] An air jet pipe (not shown) is connected to the lower side of the levitation unit 11. The air jet pipe is connected to a pump via a valve and an air flow meter, for example. The valve and the air flow meter are connected to a controller 40 by a signal line or the like. The amount of levitation of the substrate 50 above the stage surface 10a is controlled by the controller 40 controlling the valve and the pump.

[0020] The stage 10 may include a gripping mechanism (not shown) for transporting the substrate 50. The stage 10 may transport the substrate 50 by gripping, for example, an edge portion of the substrate 50 or a center portion of the substrate 50 by the gripping mechanism.

[0021] <Substrate> 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, for example, amorphous silicon. The laser treatment is intended to polycrystallize, monocrystallize, modify, inactivate impurities, and stabilize impurities in the semiconductor film in the substrate 50. For example, at least a part of the amorphous semiconductor film is transformed into polycrystal by irradiation with laser light. Note that the laser treatment is not limited to treatments intended for these purposes. It may include any treatment in which the substrate 50 is irradiated with laser light to perform heat treatment. In addition, the substrate 50 is not limited to a glass substrate or a semiconductor substrate as long as it is subjected to laser treatment.

[0022] <Laser irradiation part> The laser irradiation unit 20 irradiates laser light. The laser irradiation unit 20 irradiates the substrate 50 with, for example, excimer laser light. Note that the laser light irradiated by the laser irradiation unit 20 is not limited to excimer laser light, and the laser light may be irradiated according to the target laser processing. The irradiation spot 21 of the laser light irradiated by the laser irradiation unit 20 onto the substrate 50 is, for example, a line extending in the Y-axis direction.

[0023] <Flying height measuring device: Flying height> FIG. 4 is a diagram illustrating the flying height measured by the flying height measuring device in the substrate flying type laser processing device according to the first embodiment. As shown in FIG. 4, the flying height measuring device 30 measures the flying height H of the substrate 50. The flying height H of the substrate 50 is called the distance from the stage surface 10a to the lower surface 50b of the substrate 50. The distance from the flying height measuring device 30 to the upper surface 50a of the substrate 50 is called the distance L1, the distance from the flying height measuring device 30 to the lower surface 50b of the substrate 50 is called the distance L2, and the distance from the flying height measuring device 30 to the stage surface 10a, i.e., the unit surface 11a is called the distance L3. Then, the flying height H of the substrate 50 is given by flying height H=distance L3-distance L2.

[0024] <Flying height measuring device: Laser displacement meter> The flying height measuring device 30 includes, for example, a laser displacement meter 31 and a height adjustment stage 32. The laser displacement meter 31 irradiates the substrate 50 and the stage 10 with a laser beam, and receives the reflected light of the laser beam reflected by the substrate 50 and the stage 10. The laser displacement meter 31 simultaneously measures the distances L1, L2, and L3 based on the difference in reflectance between the reflected light of the laser beam reflected by the upper surface 50a of the substrate 50, the reflected light of the laser beam reflected by the lower surface 50b of the substrate 50, and the reflected light of the laser beam reflected by the stage surface 10a. This allows the laser displacement meter 31 to measure the flying height H. In this way, the flying height H of the substrate 50 is measured by irradiating the substrate 50 with a laser beam.

[0025] The height adjustment stage 32 is attached to 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, i.e., the height. The laser displacement meter 31 is set with a measurement range R that can measure the distances L1, L2, and L3. If the distances L1, L2, and L3 exceed the measurement range, the floating amount H of the substrate 50 cannot be measured with high accuracy. Therefore, the height adjustment stage 32 adjusts the height of the laser displacement meter 31 so that the distances L1, L2, and L3 are within the measurement range. Note that the floating amount measuring device 30 is not limited to one that includes the laser displacement meter 31, as described later.

[0026] The flying height measuring device 30 may include a translation stage 33. The translation stage 33 is a rod-shaped movable stage extending in the Y-axis direction on a horizontal plane above the stage 10. A laser displacement meter 31 is attached to the translation stage 33 via a height adjustment stage 32. Therefore, the laser displacement meter 31 and the height adjustment stage 32 are slidable in the Y-axis direction along the translation stage 33. In this way, the flying height measuring device 30 measures the flying height H of the substrate 50 along the Y-axis direction.

[0027] The flying height measuring device 30 may include a translation stage 34. Two translation stages 34 are arranged to sandwich the stage 10 in the Y-axis direction. One translation stage 34 is arranged to extend in the X-axis direction along the end side of the stage 10 in the +Y-axis direction, and the other translation stage 34 is arranged to extend in the X-axis direction along the end side in the -Y-axis direction. Each translation stage 34 is attached with a frame 35 extending upward so as to be slidable in the X-axis direction. The frame 35 of one translation stage 34 supports one end of the translation stage 33, and the frame 35 of the other translation stage 34 supports the other end of the translation stage 33. Thus, the translation stage 33 is movable in the X-axis direction. In this way, the flying height measuring device 30 measures the flying height H of the substrate 50 along the X-axis direction and the Y-axis direction.

[0028] <Comparative example: Flying height measuring device> Next, a floating height measuring device of a substrate floating type laser processing apparatus according to a comparative example will be described. Fig. 5 is a diagram illustrating a floating height measuring device of a substrate floating type laser processing apparatus according to a comparative example. As shown in Fig. 5, a floating height measuring device 130 of the comparative example also includes a laser displacement meter 131, a height adjustment stage 132, and a translation stage 33. The stage 10 and the laser irradiation unit 20 of the substrate floating type laser processing apparatus 101 according to the comparative example are similar to the stage 10 and the laser irradiation unit 20 in the substrate floating type laser processing apparatus 1 of the first embodiment.

[0029] Like the laser displacement meter 31, the laser displacement meter 131 also irradiates the substrate 50 and the stage 10 with a laser beam and receives the reflected light of the laser beam reflected by the substrate 50 and the stage 10. The laser displacement meter 131 simultaneously measures the distances L1, L2, and L3 based on the difference in reflectance between the reflected light of the laser beam reflected by the upper surface 50a of the substrate 50, the reflected light reflected by the lower surface 50b of the substrate 50, and the reflected light reflected by the stage surface 10a. This allows the laser displacement meter 131 to measure the flying height H. When the flying height measuring device 130 measures the flying height of the substrate 50 with the laser displacement meter 131, it measures by moving the measurement position by the translation stage 33. The laser displacement meter 131 has a measurement range that can measure the distances L1, L2, and L3. If the distance L1, the distance L2, and the distance L3 exceed the measurement range, the laser displacement meter 131 cannot measure the floating amount of the substrate with high accuracy.

[0030] 5, the stage surface 10a is composed of a plurality of unit surfaces 11a. The positions of the plurality of unit surfaces 11a may be misaligned in the Z-axis direction. Therefore, if the relationship between the levitation unit 11 and the stage 10 is not flat when viewed from the entire stage surface 10a, the movement of the laser displacement meter 131 may exceed the measurement range R. Therefore, the levitation amount of the substrate 50 cannot be measured with high accuracy.

[0031] Thus, the problem with the substrate floating type laser processing device 101 of the comparative example is that when measuring the floating amount of the substrate 50 with the laser displacement meter 131, the stage surface 10a is not flat as a whole, so that moving the laser displacement meter 131 may exceed the measurement range R. In that case, it is necessary to manually move the height adjustment stage 132 and adjust the height of the laser displacement meter 131 so that the distances L1, L2, and L3 are within the measurement range R.

[0032] <This embodiment: Flying height measuring device and controller control> Next, a flying height measuring device in the substrate flying type laser processing apparatus 1 of this embodiment will be described. Fig. 6 is a configuration diagram illustrating an example of a flying height measuring device and a controller in the substrate flying type laser processing apparatus according to embodiment 1. As shown in Fig. 6, the flying height measuring device 30 of this embodiment is connected to a controller 40. The flying 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.

[0033] The laser displacement meter controller 41 is connected to the laser displacement meter 31 by a signal line or the like including a wired line such as a fiber or a wireless line. The laser displacement meter controller 41 is connected to a stage controller 42 by a signal line or the like. The stage controller 42 is connected to a servo amplifier 43 by a signal line or the like. The servo amplifier 43 is connected to the height adjustment stage 32 by a signal line or the like.

[0034] The laser displacement meter controller 41 receives the distances L1, L2, and L3 from the laser displacement meter 31 via a signal line or the like, as well as height information including the flying height H measured from these. 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.

[0035] The stage controller 42 receives height information including the measured flying height H from the flying height measurement device 30. The stage controller 42 adjusts the distance between the flying height measurement device 30 and the substrate 50 based on a preset target value and the input flying height H.

[0036] Specifically, the stage controller 42 compares the input flying height H with a preset target value G. Then, when the difference Δ=HG between the input flying height H and the set target value G is negative, the stage controller 42 outputs a height command value for the Z axis to the servo amplifier 43 so that the flying height H becomes larger 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=HG between the input flying height H and the set target value G is positive, the stage controller 42 outputs a height command value for the Z axis to the servo amplifier 43 so that the flying height H becomes smaller than the target value G. In this way, the distance between the flying height measuring device 30 and the substrate 50 is automatically adjusted.

[0037] The stage controller 42 may include a storage unit that stores the input distance L1, distance L2, and distance L3, as well as the measured floating amount H. Furthermore, if the difference between the target value and the input floating amount H exceeds a predetermined range, the stage controller 42 excludes the input floating amount H from the distance adjustment data. For example, peculiar points on the stage surface 10a, such as gaps between the floating units 11, air ejection holes of the floating units 11, etc., are excluded from the adjustment data.

[0038] The servo amplifier 43 receives a height command value for the Z axis of the height adjustment stage 32 from the stage controller 42. Meanwhile, the servo amplifier 43 obtains height information at which the laser displacement meter 31 is located from the height adjustment stage 32. For example, the servo amplifier 43 obtains the Z-axis height value at which the laser displacement meter 31 is located from an encoder provided on the height adjustment stage 32. Then, the servo amplifier 43 operates the height adjustment stage 32 until the height information obtained from the height adjustment stage 32 becomes equal to the height command value received from the stage controller 42.

[0039] Even if the positions of the multiple unit surfaces 11a are misaligned in the Z-axis direction and the relationship between the levitation unit 11 and the stage 10 is not flat when viewed as a whole of the stage surface 10a, the controller 40 adjusts the height of the laser displacement meter 131 so that the distances L1, L2, and L3 are within the measurement range R. Therefore, the distances L1, L2, and L3 do not exceed the measurement range R. This makes it possible to measure the levitation amount of the substrate 50 with high accuracy.

[0040] In this way, the substrate floating type laser processing device 1 of this embodiment can automatically adjust the distance between the floating height measuring device 30 and the substrate 50 by feedback control in accordance with the measured floating height H. The floating height H of the substrate 50 is measured, for example, by irradiating the substrate 50 and the stage 10 with laser light. Then, the distance between the floating height measuring device 30 and the substrate 50 is adjusted using a feedback mechanism that inputs the measured floating height of the substrate 50. This makes it possible to prevent the measured distances L1, L2, and L3 from exceeding the measurement range R.

[0041] <Method of measuring board flying height> Next, a method for measuring the floating amount of the substrate 50 will be described. Fig. 7 is a flow chart illustrating a method for measuring the floating amount of the substrate using the substrate floating type laser processing apparatus according to the first embodiment.

[0042] As shown in step S11 of FIG. 7, first, the flying height measuring device 30 is used to measure the flying height H at a predetermined position of the substrate 50. The flying height measuring device 30 includes, for example, a laser displacement meter 31. The flying height H of the substrate 50 is measured by irradiating the substrate 50 and the stage 10 with a laser light. The predetermined position of the substrate 50 may be any position. For example, it may be a position on the floating unit 11 located at the end of the substrate 50 on the +Y axis side. For example, the laser displacement meter 31 simultaneously measures the distance L1, the distance L2, and the distance L3 based on the difference in reflectance between the reflected light of the laser light reflected by the upper surface 50a of the substrate 50, the reflected light reflected by the lower surface 50b of the substrate 50, and the reflected light reflected by the stage surface 10a. As a result, the flying height measuring device 30 measures the flying height H=distance L3-distance L2. Note that the flying height measuring device 30 is not limited to one including the laser displacement meter 31.

[0043] Next, as shown in step S12, the distance between the flying height measuring device 30 and the substrate 50 is automatically adjusted in accordance with the measured flying height H. The controller 40 to which the flying height H is input from the flying height measuring device 30 adjusts the distance between the flying height measuring device 30 and the substrate 50 based on a preset target value and the input flying height H. In this manner, the substrate flying type laser processing device 1 of this embodiment adjusts the distance between the flying height measuring device 30 and the substrate 50 using a feedback mechanism that inputs the measured flying height of the substrate 50.

[0044] Next, as shown in step S13, it is determined whether the measurement of the floating height H of the substrate has been completed. If it has been completed (Yes), the process is terminated. If it has not been completed (No), as shown in step S14, the floating height measuring 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 using the parallel movement stage 33. This allows a position on the substrate 50 that is different from the predetermined position to be measured. Furthermore, the substrate 50 may be moved by the gripping portion of the stage 10 so that a different position on the substrate 50 can be measured.

[0045] Next, returning to step S11, the flying height measuring device 30 is used to measure the flying height H of the substrate 50. Then, steps S11 to S14 are repeated until the measurement is completed. Therefore, the distance between the flying height measuring device 30 and the substrate 50 is adjusted every time the flying height of the substrate 50 is measured at each measurement position. Therefore, at each measurement position, the distances L1, L2, and L3 are adjusted accordingly so as to approach the target values ​​within the measurement range R. This makes it possible to measure the flying height of the substrate 50 with high accuracy at each measurement position. In this manner, the flying height of the substrate 50 is measured.

[0046] <Method for measuring static board flying height> As an example of a method for measuring the floating amount H of the substrate 50, a method for statically measuring the floating amount H of the substrate 50 will be described. "Statically" refers to a case where the floating amount H of the substrate 50 is measured without transporting the substrate 50. Fig. 8 is a perspective view that typically illustrates a method for statically measuring the floating amount of the substrate in the substrate floating type laser processing apparatus according to the first embodiment.

[0047] 8, when measuring the floating amount H of the substrate 50 statically without transporting the substrate 50, the translation stage 33 and the translation stage 34 are used to move the floating amount measuring device 30 while measuring the floating amount H of the substrate 50. Then, the position of the substrate 50 placed on the stage surface 10a is changed while measuring the floating amount H of the substrate 50 over the entire stage surface 10a. This makes it possible to find in advance the points where the floating amount between the stage 10 and the substrate 50 is smaller than other parts and the points of contact. Therefore, it is possible to suppress the generation of dust and the like due to contact between the substrate 50 and the stage 10.

[0048] <Method for measuring dynamic board flying height> Next, as an example of a method for measuring the floating amount H of the substrate 50, a method for dynamically measuring the floating amount H of the substrate 50 will be described. Dynamic refers to a case where the floating amount H of the substrate 50 is measured while the substrate 50 is being transported. Fig. 9 is a perspective view that typically illustrates a method for dynamically measuring the floating amount of the substrate in the substrate floating type laser processing apparatus according to the first embodiment.

[0049] As shown in FIG. 9, when the floating amount H of the substrate 50 is dynamically measured while the substrate 50 is being transported, the floating amount H of the substrate 50 is measured while the substrate 50 is being transported using the gripping portion of the stage 10. The method of dynamically measuring the floating amount H of the substrate 50 is important, for example, when measuring the floating amount H of the substrate 50 arranged on the stage 10 below the laser irradiation unit 20. If the substrate 50 is pushed up or bent when being transported below the laser irradiation unit 20, the focus of the laser light is shifted and the desired laser light cannot be irradiated. Therefore, by measuring the floating amount H of the substrate 50 dynamically below the laser irradiation unit 20 in advance, the irradiation position of the laser light can be measured with high accuracy. This can improve the performance of the laser processing.

[0050] Next, the effect of this embodiment will be described. The substrate floating type laser processing device 1 of this embodiment can automatically adjust the distance between the floating amount measuring device 30 and the substrate 50. That is, by feeding back the output of the laser displacement meter 31 to control the height, even if the measurement position of the laser displacement meter 31 moves, the distance L2 and the distance L3 are automatically set 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 floating amount measuring device 30. For example, the distance between the floating amount measuring device 30 and the substrate 50 is automatically adjusted to follow a target value within the measurement range R. Therefore, since the measurement range is not exceeded, the floating amount of the substrate 50 can be measured with high accuracy.

[0051] In addition, since the floating amount H of the substrate 50 over the entire stage surface 10a is measured, it is possible to find in advance the locations where the floating amount between the stage 10 and the substrate 50 is smaller than other locations and the locations of contact. This makes it possible to suppress the generation of dust and the like due to contact between the substrate 50 and the stage 10.

[0052] Furthermore, the irradiation position of the laser light can be measured with high accuracy by measuring the dynamic floating amount H of the substrate 50 below the laser irradiation unit 20. This makes it possible to improve the performance of the laser processing.

[0053] The floating amount H of the substrate 50 is measured by irradiating the substrate 50 and the stage 10 with a laser beam. Therefore, a highly accurate measurement can be performed using the wavelength of the laser beam.

[0054] In the above, the feedback mechanism is used to adjust the distance between the floating height measuring device 30 and the substrate 50, but the user may manually adjust the height adjustment stage 32 so that the distances L1 to L3 fall within the measurement range R. Also, adjusting the height of the floating unit 11 side so that the distances L1 to L3 fall within the measurement range R is not excluded.

[0055] Furthermore, the distance between the flying height measuring device 30 and the stage surface 10a may be measured in advance and stored in the storage unit. That is, the controller 40 includes a storage unit that stores the distance between the flying height measuring device 30 and the stage surface 10a in advance, and the controller 40 automatically adjusts the distance between the flying height measuring device 30 and the substrate 50 to within a target value within the measurement range R, using the distance between the flying height measuring device 30 and the stage surface 10a stored in the storage unit, so that the height of the laser displacement meter 31 is constant no matter where the laser displacement meter 31 moves on the XY plane. Therefore, since the measurement range R is not exceeded, the flying height of the substrate 50 can be measured with high accuracy.

[0056] (Embodiment 2) Next, a substrate floating type laser processing apparatus according to embodiment 2 will be described. In this embodiment, the floating height measuring device includes a camera. Figures 10 and 11 are diagrams that typically illustrate the operation of the floating height measuring device measuring the floating height of the substrate in the substrate floating type laser processing apparatus according to embodiment 2.

[0057] As shown in Figs. 10 and 11, the flying height measuring device 60 of the substrate flying type laser processing device 2 of this embodiment includes a camera 61 and a height adjustment stage 62. The camera 61 captures an image of the upper surface 50a of the substrate 50. The height adjustment stage 62 is attached to the camera 61. The height adjustment stage 62 can adjust the position of the focal point of the camera 61 in the Z-axis direction, that is, the height. The camera 61 has a measurement range in which it can be focused. If the focal position exceeds the measurement range, the flying height H of the substrate 50 cannot be measured with high accuracy. Therefore, the height adjustment stage 32 adjusts the height of the camera 61 so that the focal point is within the measurement range.

[0058] When measuring the floating amount H of the substrate 50 using the camera 61, the focal position of the camera 61 is aligned with the upper surface 50a of the substrate 50 before and after the substrate 50 is floated, and the floating amount H is measured. That is, as shown in Fig. 10, the air jet of the floating unit 11 is turned off and the substrate 50 is lowered onto the floating unit 11 (Procedure A). Then, while adjusting the height of the camera 61 by the height adjustment stage 62, the height of the camera 61 at which the focal point of the camera 61 matches the upper surface 50a of the substrate 50 is found (Procedure B).

[0059] 11, the air jet of the levitation unit 11 is turned on to levitate the substrate 50 (procedure C). Then, the height of the camera 61 is again adjusted by the height adjustment stage 62 to find the height of the camera 61 at which the focus of the camera 61 is aligned with the upper surface 50a of the substrate 50 (procedure D). Next, the levitation amount H is measured as the difference between the height found by procedure B and the height found by procedure D.

[0060] Thus, in this embodiment, the camera 61 can measure the floating amount H of the substrate 50 from the position where the focus is on the upper surface 50a of the substrate 50 when the substrate 50 is brought into contact with the stage 10, and from the position where the focus is on the upper surface 50a of the substrate 50 when the substrate 50 is floated above the stage 10.

[0061] When the camera 61 can capture an image of the lower surface 50b of the substrate 50 and the stage surface 10a through the substrate 50, the camera 61 may measure the floating amount H of the substrate 50 from a position where the focus is on the upper surface 50a or the lower surface 50b of the substrate 50 and a position where the focus is on the stage surface 10a. Specifically, the floating amount H may be measured as the difference between the height of the camera 61 at a position where the focus is on the upper surface 50a or the lower surface 50b of the substrate 50 and the height of the camera 61 at a position where the focus is on the stage surface 10a. When the focus is on the upper surface 50a of the substrate 50, the thickness of the substrate 50 is subtracted from the height difference to obtain the floating amount.

[0062] According to the substrate floating type laser processing apparatus 2 of this embodiment, the floating amount measuring device 60 uses a camera 61. Since the floating amount H of the substrate 50 can be measured from the focal position of the camera 61, it is possible to easily measure the floating amount H. Other configurations and effects are included in the description of the first embodiment.

[0063] (Embodiment 3) Next, a substrate floating type laser processing apparatus according to embodiment 3 will be described. In this embodiment, the floating height measuring device includes a length measuring device. Fig. 12 and Fig. 13 are diagrams illustrating an example of an operation of the floating height measuring device measuring the floating height of the substrate in the substrate floating type laser processing apparatus according to embodiment 3.

[0064] As shown in FIG. 12 and FIG. 13, the floating height measuring device 70 of the substrate floating type laser processing device 3 of this embodiment includes a length measuring device 71. The length measuring device 71 measures the distance to the upper surface 50a of the substrate 50. The length measuring device 71 is, for example, a contact type length measuring device, an ultrasonic displacement sensor, or a linear proximity sensor. The contact type length measuring device is, for example, a pick tester, a digital gauge, or the like, and is brought into contact with the upper surface 50a of the substrate 50 to measure the distance to the upper surface 50a of the substrate 50. The ultrasonic displacement sensor irradiates the substrate 50 with ultrasonic waves, and measures the distance to the upper surface 50a of the substrate 50 from the reflected waves of the ultrasonic waves reflected by the upper surface 50a of the substrate 50. The linear proximity sensor measures the distance to the upper surface 50a of the substrate 50 by placing a metal plate on the upper surface 50a of the substrate 50.

[0065] When measuring the levitation amount H of the substrate 50 using the length measuring device 71, the following procedure is followed. That is, as shown in Fig. 12, the air jet of the levitation unit 11 is turned off and the substrate 50 is lowered onto the levitation unit 11 (Procedure A). Then, the length measuring device 71 is placed on the upper surface 50a of the substrate 50 (Procedure B).

[0066] 13, the air jet of the levitation unit 11 is turned on to levitate the substrate 50 (step C). Then, the displacement of the length measuring device 71 when the substrate 50 is levitated is measured (step D). The levitation amount H can be measured from the displacement of the length measuring device 71.

[0067] Thus, in this embodiment, the length measuring device 71 can measure the floating amount H of the substrate 50 from the distance to the upper surface 50a of the substrate 50 when the substrate 50 is in contact with the stage 10, and the distance to the upper surface 50a of the substrate 50 when the substrate 50 is floated above the stage 10.

[0068] According to the substrate floating type laser processing device 3 of this embodiment, the floating height measuring device 70 uses a length measuring device 71. By using the length measuring device 71, it is possible to measure the distance to the upper surface 50a of the substrate 50 with high accuracy. Other configurations and effects are included in the description of the first and second embodiments.

[0069] The invention made by the inventor has been specifically described above based on an embodiment, but it goes without saying that the present invention is not limited to the above embodiment and can be modified in various ways without departing from the gist of the invention. [Explanation of symbols]

[0070] 1, 2, 3 Substrate floating type laser processing device 10 Stages 10a Stage surface 11. Levitation Unit 11a Unit surface 20 Laser irradiation section 21 Irradiation Spot 30 Floating height measuring device 31 Laser displacement gauge 32 Height adjustable stage 33, 34 Translation stage 40 Controller 41 Laser displacement gauge controller 42 Stage Controller 43 Servo amplifier 50 Substrates 50a top 50b Bottom side 60 Floating height measuring device 61 Camera 62 Height adjustable stage 70 Floating height measuring device 71 Length measuring device

Claims

1. A substrate floating laser processing apparatus including: A stage for lifting and transporting the substrate; a flying height measuring device for measuring the flying height of the substrate, the flying height being the distance between the upper surface of the stage and the lower surface of the substrate on the stage; and a controller to which the fly height is input from the fly height measurement device, the controller being configured to determine a difference between the measured fly height and a preset target value; Where: the flying height measurement device is configured so that a first distance from the flying height measurement device to an upper surface of the substrate, a second distance from the flying height measurement device to a lower surface of the substrate, and a third distance from the flying height measurement device to an upper surface of the stage are within a measurement range; The controller automatically adjusts the distance between the flying height measurement device and the substrate in the vertical direction by moving the flying height measurement device along the vertical direction based on the determined difference.

2. The floating amount of the substrate is measured by irradiating the substrate and the stage with a laser light.

2. The substrate floating type laser processing apparatus according to claim 1.

3. adjusting the distance between the flying height measuring device and the substrate using a feedback mechanism that inputs the measured flying height of the substrate; 2. The substrate floating type laser processing apparatus according to claim 1.

4. the flying height measuring device includes a laser displacement meter that irradiates the laser light onto the substrate and the stage and receives light reflected by the substrate and the stage from the laser light, the laser displacement meter measures the floating amount of the substrate from light reflected by the laser light reflected from a lower surface of the substrate and light reflected by a top surface of the stage.

3. The substrate floating type laser processing apparatus according to claim 2.

5. the flying height measuring device includes a camera that captures an image of an upper surface of the substrate, the camera measures the amount of levitation of the substrate from a position where the focus is on the top surface of the substrate when the substrate is brought into contact with the stage, and a position where the focus is on the top surface of the substrate when the substrate is levitated above the stage.

2. The substrate floating type laser processing apparatus according to claim 1.

6. the flying height measuring device includes a camera that captures an image of an upper surface of the substrate, the camera measures the floating amount of the substrate from a position where the focus is on the upper surface or the lower surface of the substrate and a position where the focus is on the upper surface of the stage; 2. The substrate floating type laser processing apparatus according to claim 1.

7. the flying height measuring device includes a length measuring device for measuring a distance to an upper surface of the substrate, the length measuring device measures a floating amount of the substrate from a distance to an upper surface of the substrate when the substrate is brought into contact with the stage, and a distance to an upper surface of the substrate when the substrate is floated above the stage.

2. The substrate floating type laser processing apparatus according to claim 1.

8. the flying height measurement device includes a translation stage extending in one direction on a horizontal plane above the stage, the flying height measuring device measures the flying height of the substrate along the one direction; 2. The substrate floating type laser processing apparatus according to claim 1.

9. the translation stage is movable in another direction perpendicular to the one direction in a horizontal plane above the stage; 9. The substrate floating type laser processing apparatus according to claim 8.

10. the stage has a plurality of levitation units that eject air to levitate the substrate; an upper surface of the stage including upper surfaces of the plurality of the levitation units; 2. The substrate floating type laser processing apparatus according to claim 1.

11. the controller excludes the input flying height from the distance adjustment data when a difference between the target value and the input flying height exceeds a predetermined range.

2. The substrate floating type laser processing apparatus according to claim 1.

12. the controller includes a storage unit that stores a distance between the flying height measurement device and the stage, the controller automatically adjusts the distance between the flying height measuring device and the substrate using the interval stored in the storage unit; 2. The substrate floating type laser processing apparatus according to claim 1.

13. measuring the floating amount of the substrate, the floating amount being the distance between an upper surface of the stage and a lower surface of the substrate on the stage, using a floating amount measuring device that is disposed on a stage for floating and transporting the substrate and that measures the floating amount of the substrate; a step of causing a controller to which the flying height is input from the flying height measuring device to determine a difference between the measured flying height and a preset target value; automatically adjusting a distance between the flying height measurement device and the substrate in a vertical direction by moving the flying height measurement device along a vertical direction based on the determined difference; Equipped with In the step of measuring the flying height, a first distance from the flying height measuring device to the upper surface of the substrate, a second distance from the flying height measuring device to the lower surface of the substrate, and a third distance from the flying height measuring device to the upper surface of the stage are set within a measurement range; How to measure flying height.

14. In the step of measuring the flying height of the substrate, measuring the floating amount of the substrate by irradiating the substrate and the stage with a laser light; The method for measuring flying height according to claim 13.

15. In the step of automatically adjusting, adjusting the distance between the flying height measuring device and the substrate using a feedback mechanism that inputs the measured flying height of the substrate; The method for measuring flying height according to claim 13.

16. the flying height measuring device includes a laser displacement meter that irradiates the laser light onto the substrate and the stage and receives light reflected by the substrate and the stage from the laser light, In the step of measuring the flying height of the substrate, the laser displacement meter measures the floating amount of the substrate from light reflected by the laser light reflected from a lower surface of the substrate and light reflected by a top surface of the stage. The method for measuring flying height according to claim 14.

17. the flying height measuring device includes a camera that captures an image of an upper surface of the substrate, In the step of measuring the flying height of the substrate, the camera measures the amount of levitation of the substrate from a position where the focus is on the top surface of the substrate when the substrate is brought into contact with the stage, and a position where the focus is on the top surface of the substrate when the substrate is levitated above the stage. The method for measuring flying height according to claim 13.

18. the flying height measuring device includes a camera that captures an image of an upper surface of the substrate, In the step of measuring the flying height of the substrate, the camera measures the floating amount of the substrate from a position where the focus is on the upper surface or the lower surface of the substrate and a position where the focus is on the upper surface of the stage; The method for measuring flying height according to claim 13.

19. the flying height measuring device includes a length measuring device for measuring a distance to an upper surface of the substrate, In the step of measuring the flying height of the substrate, the length measuring device measures a floating amount of the substrate from a distance to an upper surface of the substrate when the substrate is brought into contact with the stage, and a distance to an upper surface of the substrate when the substrate is floated above the stage. The method for measuring flying height according to claim 13.

20. the flying height measurement device includes a translation stage extending in one direction on a horizontal plane above the stage, In the step of measuring the flying height of the substrate, the flying height measuring device measures the flying height of the substrate along the one direction; The method for measuring flying height according to claim 13.

21. In the step of measuring the flying height of the substrate, the translation stage is movable in another direction perpendicular to the one direction in a horizontal plane above the stage; The method for measuring flying height according to claim 20.

22. the stage has a plurality of levitation units that eject air to levitate the substrate; an upper surface of the stage including upper surfaces of the plurality of the levitation units; The method for measuring flying height according to claim 13.

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

24. a storage unit that stores a distance between the flying height measuring device and the stage, In the step of automatically adjusting, the controller automatically adjusts the distance between the flying height measuring device and the substrate using the interval stored in the storage unit; The method for measuring flying height according to claim 13.

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