Chuck table, method of manufacturing a support plate thereof, and laser processing apparatus including the same

Abstract

The present disclosure relates to a chuck table, a laser processing apparatus including the same, and a method for manufacturing a support plate of the chuck table, and the chuck table includes a support plate having an air flow groove with a depth less than a width to adsorb an object to be processed by vacuum pressure, and a vacuum pump, and since the depth of the air flow groove is low, warping of the processed object can be prevented when a vertical direction force of suctioning a portion of the processed object (or substrate) is reduced. Accordingly, a spot generated in the processed object during laser processing of the processed object can be prevented, and a reduction in processing uniformity can be addressed.

Description

TECHNICAL FIELD

[0001] The disclosure relates to a chuck table, a laser processing apparatus including the chuck table, and a method for manufacturing a support plate of the chuck table, and more particularly, to a chuck table that attracts an object to be processed by vacuum pressure, a laser processing apparatus including the chuck table, and a method for manufacturing a support plate of the chuck table. BACKGROUND

[0002] Generally, in a laser processing apparatus that irradiates an object to be processed (hereinafter, referred to as a processed object) with a laser beam to process the object to be processed, the object to be processed is processed while being supported by a chuck table.

[0003] For example, the laser processing apparatus can allow a processed object such as a substrate or a thin film to be placed on a chuck table in a chamber, and perform high-temperature annealing on the processed object, thereby crystallizing the substrate or the thin film.

[0004] Particularly, an eximer laser annealing (ELA) method induces crystallization by irradiating a substrate or a thin film with an eximer laser to immediately heat the substrate or the thin film. The ELA method has excellent annealing uniformity over the entire substrate or thin film, and is thus easily applied to a large-area substrate. In addition, since only a local area irradiated with a laser beam is immediately heated, the ELA method has excellent applicability to a thin film substrate and high productivity. Therefore, the ELS method has been actively researched in recent years.

[0005] The laser processing apparatus can process processed objects having various sizes and shapes, and the processed objects must be firmly fixed at a determined position by using a chuck table to achieve high processing precision (or processing uniformity).

[0006] Generally, a chuck table supports (or fixes) a substrate by using vacuum pressure to attract the substrate to be firmly fixed, and defines a suction hole (or a suction groove) for vacuum attraction in a top surface of the chuck table.

[0007] Generally, the suction holes or the suction grooves are defined by using a mechanical process. However, when the mechanical process is used, the suction holes or the suction grooves inevitably have a wide width due to a limitation in the process, and also have a large depth according to the wide width. Thus, when a vacuum pressure is formed through the suction holes or the suction grooves, when a portion of the substrate corresponding to the suction holes or the suction grooves is suctioned by the vacuum pressure, warping of the substrate is generated, and in irradiating the substrate with a laser beam, since a height difference between a bottom surface of the suction groove and a top surface of the support plate is large, reflection characteristics such as reflectivity of the bottom surface of the suction groove and the top surface of the support plate show a large difference. Thus, mura is generated on the substrate during the laser processing, and the processing uniformity is reduced.

[0008] [Related Art Document]

[0009] [Patent Document]

[0010] Korean Patent No. 10-1011932 SUMMARY

[0011] The present disclosure provides a chuck table capable of adsorbing an object to be processed by using a vacuum pressure and ensuring high processing uniformity, a laser processing apparatus including the chuck table, and a method for manufacturing a support plate of the chuck table.

[0012] According to an exemplary embodiment, a chuck table includes a support plate including a suction hole and an airflow groove communicating with the suction hole, and supporting an object to be processed; and a vacuum pump connected to the suction hole to provide a vacuum suction force for fixing the object to be processed. Here, a depth of the airflow groove is smaller than a width thereof.

[0013] The airflow groove can have a depth of 10 micrometers to 100 micrometers.

[0014] The airflow groove can have a width of 0.1 millimeters to 5 millimeters.

[0015] The airflow groove can include micro-embossing formed on a bottom surface thereof.

[0016] The bottom surface of the airflow groove can have a surface roughness of 0.01 micrometers to 1 micrometer.

[0017] The support plate can have a curved support surface.

[0018] The support plate can be made of metal.

[0019] The object to be processed can be optically transmissive.

[0020] According to another exemplary embodiment, a laser processing apparatus includes a chuck table, a laser irradiation unit configured to irradiate an object to be processed with a laser beam, and a reflected beam removal unit configured to remove a reflected beam of the laser beam reflected by the object to be processed and a support plate.

[0021] The laser irradiation unit can irradiate the laser beam having a linear beam shape onto the object to be processed obliquely at a predetermined angle.

[0022] According to yet another exemplary embodiment, a method for manufacturing a support plate of a chuck table includes preparing a base plate having a plate shape, forming an airflow groove having a smaller depth than width in a surface of the base plate, and forming a suction hole communicating with the airflow groove in the base plate. Here, the forming of the airflow groove includes partially wet-etching the surface of the base plate.

[0023] The partially wet-etching the surface of the base plate can include forming a pattern mask having an opening on the base plate, providing an etchant on the base plate on which the pattern mask is formed, removing the pattern mask, and providing the etchant to the surface of the base plate on which the pattern mask is removed.

[0024] Before the providing of the etchant to the surface of the base plate, in the partially wet-etching the surface of the base plate, the steps of forming the pattern mask, providing the etchant on the base plate, and removing the pattern mask can be repeatedly performed a plurality of times. Here, when the forming of the pattern mask is performed again, a pattern mask having an opening with an increased area can be formed.

[0025] The forming of the pattern mask can be performed by printing a pattern on the base plate.

[0026] When the etchant is provided on the base plate, the surface of the base plate can be etched by 1 to 50 micrometers.

[0027] The method can further include forming a micro-embossing on a bottom surface of the airflow groove.

[0028] The base plate can be made of metal. BRIEF DESCRIPTION OF DRAWINGS

[0029] The exemplary embodiments can be understood more fully by the following description taken in conjunction with the accompanying drawings, in which:

[0030] Figure 1 FIG. 1 is a view illustrating a chuck table according to an exemplary embodiment.

[0031] Figure 2 FIG. 2 is a conceptual view for explaining a support plate according to an exemplary embodiment.

[0032] Figure 3 FIG. 3 is a cross-sectional view illustrating a micro-embossing formed on a bottom surface of an airflow groove according to an exemplary embodiment.

[0033] Figure 4 is a view showing a laser processing apparatus according to another exemplary embodiment.

[0034] Figure 5 is a flowchart representing a method for manufacturing a support plate of a chuck table according to another exemplary embodiment.

[0035] Figure 6 is a view sequentially showing formation of an air flow groove according to another exemplary embodiment. DETAILED DESCRIPTION

[0036] Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings. The present application may, however, be embodied in different forms, and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art. Like reference numerals refer to like elements throughout the specification. Furthermore, in the drawings, the size and relative sizes of layers and regions are exaggerated for clarity.

[0037] Figure 1 is a view showing a chuck table according to an exemplary embodiment. Figure 1 (a) of FIG. 1 is a perspective view showing a support plate, and Figure 1 (b) of FIG. 1 is a schematic cross-sectional view showing a chuck table.

[0038] Referring to Figure 1 , a chuck table 100 according to an exemplary embodiment can include a support plate 110 including suction holes 111 and air flow grooves 112 communicating with the suction holes 111, and supporting an article to be processed 10 (hereinafter, referred to as a processed article), and a vacuum pump 120 providing a vacuum suction force for fixing the article to be processed 10.

[0039] The support plate 110 can support the processed article 10, and the processed article 10 can be supported on a top surface (or an upper surface) of the support plate 110. For example, the support plate 110 can have a plate shape having a first surface and a second surface (or a top surface and a bottom surface) opposite to each other, and a surface exposed to support the processed article 10 can be defined as a top surface, rather than a surface disposed on an upper side of the first surface and the second surface. Here, the processed article 10 can have a plate shape. The processed article 10 can be a substrate (or glass) and / or a thin film.

[0040] Further, the support plate 110 can include the suction holes 111 and the air flow grooves 112 communicating with the suction holes 111. The suction holes 111 can be connected to the vacuum pump 120 to form a vacuum suction path, and the processed article 10 is fixed on the support plate 110 by a vacuum (or vacuum pressure).

[0041] The air flow groove 112 can communicate with the suction hole 111, and a vacuum suction through the suction hole 111 forms a vacuum (in space) between the processed objects 10, thereby forming a vacuum suction in the air flow groove 112. In addition, the air flow groove 112 can provide a passage through which air existing between the processed objects 10 (for example, between the top surface of the support plate and the processed objects 10) escapes. Through this, an air pocket generated so that air is disposed between the top surface of the support plate 110 and the processed objects 10 can be prevented, and the processed objects 10 can be prevented from sliding due to the air pocket.

[0042] According to an exemplary embodiment, because the vacuum suction is uniformly formed over the entire top surface of the support plate 110 via the air flow groove 112 communicating with the suction hole 111, the processed objects 10 can be firmly and stably sucked and fixed (or supported).

[0043] Here, the processed objects 10 can be optically transmissive, and light (for example, a laser beam) can be transmitted through at least a portion of the processed objects 10. That is, the processed objects 10 can transmit all light without absorbing or reflecting the light, transmit only a portion of light within a certain wavelength range, or transmit only a portion of light (or a portion of the amount of light) because another portion of light is absorbed or reflected. Here, the processed objects 10 can be formed of one layer made of the same material (or composition), or formed by laminating two layers made of different materials. For example, the processed objects 10 can be a substrate on which a thin film is formed, such as a glass substrate on which amorphous silicon (α-Si) is deposited.

[0044] In addition, the chuck table 100 according to an exemplary embodiment can be used in a laser processing apparatus 200 that irradiates the processed objects 10 with a laser beam 11 to process the processed objects 10. The laser processing apparatus 200 can form crystalline silicon, such as polycrystalline silicon, on a substrate by irradiating amorphous silicon (α-Si) with a laser beam 11 to crystallize the amorphous silicon (α-Si).

[0045] Here, the glass substrate can transmit light, and the amorphous silicon (a-silicon) thin film can transmit light in a specific wavelength range. Here, when light is not transmitted through the amorphous silicon (a-silicon) thin film, the entire amorphous silicon (a-silicon) thin film can not be crystallized, or the degree of crystallization can differ depending on the distance from the incident surface of the laser beam 11. Thus, the crystallization uniformity is reduced. On the other hand, when light is transmitted through the amorphous silicon (a-silicon) thin film, light energy (or optical energy) can be uniformly transmitted above the amorphous silicon (a-silicon) thin film, and thus the entire amorphous silicon (a-silicon) thin film can be uniformly crystallized. Further, when the glass substrate absorbs light instead of transmitting light therefrom, the glass substrate can be heated to a high temperature, and the glass substrate and / or the amorphous silicon (a-silicon) thin film can be damaged by the high temperature. Further, when the glass substrate reflects light instead of transmitting light therefrom, total reflection can not be performed because light is reflected at the interface with the amorphous silicon (a-silicon) thin film, and the degree of crystallization of the amorphous silicon (a-silicon) thin film can differ depending on the distance to the interface. On the other hand, when the glass substrate transmits light, high-temperature heating caused by light absorption can be limited or prevented, and the difference in the degree of crystallization caused by interface reflection can be limited or prevented.

[0046] Thus, the processed object 10 can be optically transmissive.

[0047] Since a large-area glass substrate has a large size and a relatively small thickness compared to the size, warping can easily occur. Thus, when supporting a large-area glass substrate, it is important to reduce the width w and the depth d of the airflow groove 112. Here, the airflow groove 112 can have a depth d smaller than the width w to limit or prevent a portion of the glass substrate from being sucked into the airflow groove 112. Further, since warping easily occurs in a thin flexible substrate made of a polymer or the like, it is important to reduce the width w and the depth d of the airflow groove 112 and make the depth d in the airflow groove 112 smaller than the width w.

[0048] The support plate 110 can be made of metal. When the support plate 110 is made of ceramic, the support plate 110 can be worn due to friction with the processed object 10, particles can easily be generated, and damage such as scratches can occur in the support plate 110 and / or the processed object 10. Accordingly, the processed object 10 can not be stably supported (or fixed). Further, the air flow grooves 112 can be formed in the support plate 110 by wet etching rather than mechanical processing, and the etching rate of the support plate 110 made of ceramic can not be easily controlled. For example, due to the etching rate being too high (or too fast), the shallow air flow grooves 112 can not be formed, and due to the etching rate being too low (or too slow), the formation of the air flow grooves 112 can take a long time. Further, when etching is performed by forming the pattern mask 20, etching can be performed not only in the depth direction having directionality, but also in the width direction which is the direction toward the lower portion (or downward) of the pattern mask 20. In this case, the processed object 10 can not be stably supported on the top surface of the support plate 110. For example, the support strength of the portion protruding from the bottom surface 112a of the air flow groove 112 can be reduced, the pressure difference due to the relatively wide width of the lower portion of the air flow groove 112 can not be properly formed, and air present between the top surface of the support plate 110 and the processed object 10 can not be effectively removed.

[0049] However, when the support plate 110 is made of metal as in the exemplary embodiment, the etching rate can be controlled by adjusting the concentration of the etchant. That is, the etching rate can be easily controlled. Via this, the air flow grooves 112 can have a low (or shallow) depth, and when etching is performed by forming the pattern mask 20, over-etching of etching performed in the width direction can be limited or prevented by adjusting the time in units of minutes. The air flow grooves 112 having a low depth will be described in detail below.

[0050] Here, the metal can not only include a single metal, but also an alloy made of a plurality of metals. For example, the metal can include aluminum (Al), pure aluminum, or aluminum on which an oxide layer such as an aluminum alloy or aluminum oxide is formed. Aluminum can be etched by about 10 micrometers in about 1 minute (or 60 seconds), and via this, etching can be easily performed. Further, etching can be performed only for a short time such as one minute, and via this, over-etching of etching performed in the width direction can be limited or prevented. Other metals such as stainless steel can have a relatively low etching rate.

[0051] Figure 2 is a conceptual diagram for explaining a support plate according to an exemplary embodiment. Figure 2 (a) of FIG. 1 shows an exemplary embodiment of a support plate, and Figure 2 (b) of FIG. 1 shows a modified embodiment of a support plate.

[0052] Reference Figure 2 The gas flow groove 112 can have a depth d less than the width w, and an aspect ratio of the gas flow groove 112 can be less than 1. Here, the aspect ratio of the gas flow groove 112 can be represented by a ratio between the width and the depth (w:d) of the gas flow groove 112 or the depth d / width w.

[0053] The groove must have a predetermined width (e.g., about 0.1 mm or more than 0.1 mm) to form the groove (e.g., the gas flow groove) in the planar surface. Here, when the gas flow groove 112 has a depth d equal to or greater than the width w, the depth d of the gas flow groove 112 is too deep. Further, in the related art, the groove is formed by machining, and when the groove is formed by machining, the gas flow groove 112 inevitably has a deep depth d. Due to this, when a vacuum is formed in the gas flow groove 112, because the vertical direction force (or vacuum pressure) that sucks the processed object 10 is too large, when a portion of the processed object 10 is sucked into the gas flow groove 112, warping of the processed object 10 can occur. Further, when the chuck table 100 including the support plate 110 made of metal is used in the laser processing apparatus 200, because the height difference between the bottom surface 112a of the gas flow groove 112 and the top surface of the support plate 110 is large, the bottom surface 112a of the gas flow groove 112 that reflects the laser beam 11 and the top surface of the support plate 110 can have a large difference in reflection characteristics, e.g., reflectivity, with respect to the laser beam 11. In this case, during laser processing on the processed object 10, a spot can occur on the processed object 10, and processing uniformity can be reduced.

[0054] Accordingly, according to exemplary embodiments, the gas flow groove 112 can have a depth d less than the width w. Accordingly, by minimizing (or reducing) the depth d of the gas flow groove 112, the height difference between the bottom surface 112a of the gas flow groove 112 and the top surface of the support plate 110 can be reduced, and the difference in reflection characteristics (e.g., reflectivity) of the bottom surface 112a of the gas flow groove 112 and the top surface of the support plate 110 can be reduced. Further, by reducing the vertical direction force that sucks a portion of the processed object 10 through the low depth of the gas flow groove 112, warping of the processed object 10 can be prevented. Accordingly, a spot that occurs on the processed object 10 during laser processing on the processed object 10 can be prevented, and the limitation of reduced processing uniformity can be addressed.

[0055] Since the air flow groove 112 is formed by using the wet etching in the exemplary embodiment, it is important to secure the opening 20a of the pattern mask 20 (i.e., to secure the width of the air flow groove). In the case of the wet etching, since the reaction with the etchant is not sufficiently performed when the contact area (i.e., the reaction area) with the etchant is too small, the etching can be difficult to perform, and the air flow groove 112 can be difficult to form. Due to this, the air flow groove 112 must sufficiently secure the width w of about 0.1 mm or more than 0.1 mm to have a sufficient contact area with the etchant capable of reacting with the etchant. However, the air flow groove 112 can have the depth d smaller than the width w, because the difference in the reflection characteristics of the bottom surface 112a of the air flow groove 112 and the top surface of the support plate 110 is reduced, and according to the width w of the air flow groove 112, the depth d of the air flow groove 112 must be less than about 0.1 mm to prevent the warping of the processed object 10.

[0056] Further, the air flow groove 112 can have the depth d of 10 to 100 micrometers. When the depth d of the air flow groove 112 is greater than 100 micrometers, since the vertical direction vacuum pressure is excessively large, when a portion of the processed object 10 is suctioned to the air flow groove 112, the processed object 10 can be warped. Further, when the chuck table 100 is used in the laser processing apparatus 200, since the height difference between the bottom surface 112a of the air flow groove 112 and the top surface of the support plate 110, the difference in the reflection characteristics can increase. In the related art, since the process limitation caused by forming the groove in the top surface of the support plate 110 by the mechanical processing, the groove can inevitably have the depth of about 500 micrometers or more than 500 micrometers, and even when the groove is formed by using the expensive equipment to extend the processing time, the groove having the depth of 100 micrometers or less than 100 micrometers can not be formed. However, in the exemplary embodiment, the air flow groove 112 having the depth of 100 micrometers or less than 100 micrometers can be formed by the wet etching. Therefore, the warping of the processed object 10 can be prevented by reducing the vertical direction force of suctioning a portion of the processed object 10 by the low depth of the air flow groove 112. Further, the difference between the reflection characteristics of the bottom surface 112a of the air flow groove 112 and the top surface of the support plate 110 can be reduced.

[0057] On the other hand, when the depth d of the airflow groove 112 is less than 10 micrometers, the function of the airflow groove 112 can be reduced since there is almost no height difference between the bottom surface 112a of the airflow groove 112 and the top surface of the support plate 110 (or the depth of the airflow groove is similar to the thickness tolerance of the support plate). That is, since the space with the processed object 10 is too narrow, the vacuum suction force can be reduced, and air and / or particles can not be easily discharged. Here, when the airflow groove 112 has a depth d of 10 micrometers or more (preferably, about 20 micrometers), an effective vacuum suction force can be provided, and air and / or particles can be smoothly discharged.

[0058] Therefore, the airflow groove 112 can have a depth d of 10 micrometers to 100 micrometers.

[0059] Since the emission position of the laser beam 11 emitted from the processed object 10 to the airflow groove 112 gradually approaches the emission position of the reflected beam 12 incident to the processed object 10 from the airflow groove 112 as the depth d of the airflow groove 112 decreases, the reflection characteristics at the bottom surface 112a of the airflow groove 112 can be similar to the reflection characteristics at the top surface of the support plate 110 at which the emission position of the laser beam 11 is equal to the incidence position of the reflected beam 12 reflected at the interface between the top surface of the support plate 110 and the processed object 10. Therefore, the difference between the reflection characteristics of the bottom surface 112a of the airflow groove 112 and the top surface of the support plate 110 can be reduced.

[0060] In the related art as in (b) of Figure 2 In the related art as in (b) of

[0061] However, in the exemplary embodiment as in (a) of Figure 2 In the exemplary embodiment as in (a) of

[0062] Therefore, the airflow groove 112 can have a width w of 0.1 to 5 micrometers. In the related art, due to process limitations caused by forming the groove through mechanical processing, a groove having a width of about 5 millimeters or more is inevitably formed. When the airflow groove 112 has a width w greater than 5 millimeters, the processed object 10 can be deflected only by self weight (or own weight), and the total area of the support surface 115 can be reduced. Therefore, the processed object 10 can not be stably supported. On the other hand, when the airflow groove 112 has a width w less than 0.1 millimeters, the airflow groove 112 can have a very narrow width to almost not discharge air and / or particles, and the vacuum suction force can be reduced to unstably fix the processed object 10. Further, etching can be difficult to perform due to insufficient execution of a reaction with an etchant because the contact area with the etchant capable of reacting with the etchant is too small, and thus the airflow groove 112 can be difficult to form.

[0063] Therefore, since the airflow groove 112 has a width of 0.1 to 5 millimeters in the exemplary embodiment, the airflow groove 112 can ensure functions of preventing deflection of the processed object 10 caused by own weight, smoothly discharging air and / or particles, and sufficiently providing a vacuum suction force. Further, the contact area with the etchant capable of reacting with the etchant can be sufficiently ensured.

[0064] Figure 3 FIG. 1 is a cross-sectional view illustrating a micro-embossing formed on a bottom surface of an airflow groove according to an exemplary embodiment.

[0065] Referring to Figure 3 The airflow groove 112 can include a micro-embossing 112b formed on a bottom surface 112a. That is, the micro-embossing 112b can be formed on the bottom surface 112a of the airflow groove 112. When the micro-embossing 112b is formed on the bottom surface 112a of the airflow groove 112, the micro-embossing 112b can absorb the laser beam 11, and can reduce the reflectivity (or reflection amount) of the laser beam 11 through the bottom surface 112a of the airflow groove 112. Therefore, a difference between the bottom surface 112a of the airflow groove 112 and the reflection characteristics of the top surface of the support plate 110 can be minimized.

[0066] In detail, at the top surface of the support plate 110 supporting the treated object 10, when the reflection is performed at the interface with the treated object 10, the reflection is performed at a predetermined angle, and the reflected light beam 12 has a constant path. However, at the bottom surface 112a of the air flow groove 112, the laser beam 11 transmitted through the treated object 10 and the air (layer) is reflected, and a portion (e.g., about 4%) of the amount of light of the laser beam 11 is internally reflected at the interface between the treated object 10 and the air, and only the remaining amount of light is reflected. Further, since the laser beam 11 of the remaining amount of light is emitted by diffraction at the interface between the treated object 10 and the air, the incident angle of the incident light to the bottom surface 112a of the air flow groove 112 is different from the incident angle of the laser beam 11 incident to the top surface of the support plate 110. Further, when the reflected light beam 12 reflected at the bottom surface 112a of the air flow groove 112 is incident to the treated object 10 again, a portion (e.g., about 4%) of the amount of reflected light, and the remaining amount of light is incident.

[0067] Therefore, the reflected light beam 12 reflected at the bottom surface 112a of the air flow groove 112 is not added to the internally reflected light amount having the same angle as the reflected light beam 12 reflected at the top surface of the support plate 110, but is added to the reflected light beam 12 reflected at the top surface of the support plate 110. Due to this, the difference between the amount of light at the arrival position of the reflected light beam 12 reflected at the top surface of the support plate 110 and the amount of light at the arrival position of the internally reflected reflected light beam 12 increases, and processing unevenness occurs according to the position of the treated object 10.

[0068] Therefore, by absorbing (or scattering) the laser beam 11 incident to the bottom surface 112a of the air flow groove 112 through the micro-emboss 112b to limit or prevent the reflected light beam 12 reflected at the bottom surface 112a of the air flow groove 112, the difference between the amount of light at the arrival position of the reflected light beam 12 reflected at the top surface of the support plate 110 and the amount of light at the arrival position of the internally reflected reflected light beam 12 can be reduced. That is, the difference between the reflection characteristics of the bottom surface 112a of the air flow groove 112 and the top surface of the support plate 110 can be reduced, and the processing uniformity can be improved by limiting or preventing the processing unevenness according to the position of the treated object 10.

[0069] On the other hand, when the air flow groove 112 has a width w of 1 mm or less, it is difficult to form the micro-emboss 112b on the bottom surface 112a of the air flow groove 112. Therefore, when the air flow groove 112 has a width w of 1 mm to 5 mm, the micro-emboss 112b can be formed. Further, when the air flow groove 112 has a depth d of less than 10 micrometers, it is difficult to secure the maximum height (Rmax) of the micro-emboss. Therefore, the air flow groove 112 is necessary to secure a depth d of 10 micrometers or more than 10 micrometers.

[0070] Although the micro-embossing 112b can be formed on the top surface of the support plate 110, scratches can be generated in the treated article 10 due to the rough support surface 115, and thus damage of the treated article 10 and / or the particles can be generated.

[0071] Here, the bottom surface 112a of the air flow groove 112 can have a surface roughness of 0.01 to 1 micrometers. Here, the surface roughness (or profile) can be a center average roughness (Ra). When the bottom surface 112a of the air flow groove 112 has a surface roughness of less than 0.01 micrometers, the laser beam 11 can not be effectively absorbed and / or scattered. On the other hand, when the bottom surface 112a of the air flow groove 112 has a surface roughness of more than 1 micrometer, a smooth flow of air and / or particles can not be formed in the air flow groove 112, and the particles stacked (or adhered) between the micro-embossings 112b can be difficult to remove.

[0072] Therefore, in an exemplary embodiment, when the bottom surface 112a of the air flow groove 112 has a surface roughness of 0.01 to 1 micrometers, the laser beam 11 can be effectively absorbed and / or scattered, a smooth flow of air or particles can be formed, and the particles stacked between the micro-embossings 112b can be easily removed.

[0073] Further, the support plate 110 can have a curved support surface 115. Here, the support surface 115 can be an upper end surface (or top surface) of the support plate 110 that supports the treated article 10. When the support surface 115 is formed as a flat surface and is perpendicular to the sidewall of the air flow groove 112, the treated article 10 can be scratched by a right-angled corner between the support surface 115 and the sidewall of the air flow groove 112. Therefore, damage of the treated article 10 such as scratches and / or particles can be generated.

[0074] However, in an exemplary embodiment, since the support surface 115 has a curved shape, damage of the treated article 10 and / or the particles caused by a corner between the support surface 115 and the sidewall of the air flow groove 112 can not be generated. Further, since the treated article 10 sequentially contacts the support surface 115 from a central portion to an edge thereof, air between the top surface of the support plate 110 and the treated article 10 can be introduced to the air flow groove 112, and an air trap can be effectively prevented.

[0075] Here, the arc of the curved surface has a height of 0.1 to 10 micrometers. Here, the height of the arc of the curved surface can be a height of the arc in a vertical cross section of the curved surface. When the arc of the curved surface has a height less than 0.1 micrometers, the influence of the curved surface shape on the support surface 115 can be negligible. On the other hand, when the arc of the curved surface has a height greater than 0.1 micrometers, a difference between reflection characteristics can be generated even in the support surface 115 as the height difference between the apex and the two end points increases.

[0076] Accordingly, in the exemplary embodiment, since the arc of the curved surface has a height of 0.1 to 10 micrometers, the maximum (or wide) area of the support surface 115 can contact the processed object 10 as the height difference between the apex and the two end points of the arc is small, and a difference between reflection characteristics in the support surface 115 can be limited or prevented.

[0077] Figure 4 FIG. 1 is a view illustrating a laser processing apparatus according to an exemplary embodiment. Figure 4 (a) of FIG. 1 is a perspective view illustrating a laser processing apparatus, and Figure 4 (b) of FIG. 1 is a schematic cross-sectional view illustrating a laser processing apparatus.

[0078] Hereinafter, a laser processing apparatus according to another exemplary embodiment will be described in more detail with reference to Figure 4 A laser processing apparatus according to another exemplary embodiment will be described in more detail, and features duplicated with features described in the chuck table according to the exemplary embodiment will be omitted.

[0079] The laser processing apparatus 200 according to another exemplary embodiment can include the chuck table 100 according to the exemplary embodiment, a laser irradiation unit 210 to irradiate the processed object 10 with a laser beam 11, and a reflected beam removal unit 220 to remove a reflected beam 12 of the laser beam 11 reflected at the support plate 110.

[0080] The chuck table 100 can be the chuck table 100 according to the exemplary embodiment. The chuck table 100 can have an airflow groove 112 with a depth d less than a width w, and support (or fix) the processed object 10 during processing. For example, the processed object 10 can be a glass substrate on which an amorphous silicon (a-silicon) thin film is deposited.

[0081] The laser irradiation unit 210 can irradiate the processed object 10 with the laser beam 11, and process the processed object 10 by irradiation of the laser beam 11. For example, by irradiation of the laser beam 11, the amorphous silicon (a-silicon) thin film can be crystallized into a crystalline silicon such as a polysilicon.

[0082] Here, the laser processing apparatus 200 according to another exemplary embodiment can be an excimer laser annealing (ELA) apparatus using an excimer laser. Here, the excimer laser annealing (ELA) apparatus using an excimer laser irradiates an amorphous silicon (a-silicon) thin film with an excimer laser to immediately heat the amorphous silicon (a-silicon) thin film, thereby inducing crystallization. In addition, the excimer laser annealing (ELA) apparatus using an excimer laser is easily applied to a large-area substrate because the apparatus has excellent annealing uniformity on the amorphous silicon (a-silicon) thin film and / or the entire glass substrate, and has excellent applicability to a thin plate type substrate and high productivity because the apparatus only immediately heats a local area irradiated with a laser beam 11.

[0083] The reflected beam removing unit 220 can remove the reflected beam 12 of the laser beam 11 reflected at the support plate 110, and prevent the optical system of the laser irradiation unit 210 from being damaged due to the reflected beam 12 introduced to the laser irradiation unit 210. In addition, the reflected beam removing unit 220 can prevent the reflected beam 12 having energy from affecting other components.

[0084] Here, the laser irradiation unit 210 can obliquely irradiate the laser beam 11 having a linear beam shape, i.e., a linear beam type laser beam, to the processed object 10 at a predetermined angle. That is, the laser irradiation unit 210 can irradiate the linear beam type laser beam 11 at a predetermined angle, and the irradiated linear beam type laser beam 11 can be obliquely inclined to the processed object 10. In an exemplary embodiment, when the laser beam 11 is obliquely inclined to irradiate the processed object 10 at a predetermined angle, the reflected beam 12 can be previously prevented from being emitted toward the laser irradiation unit 210. In addition, because the reflected beam removing unit 220 is provided only in consideration of the reflection angle of the reflected beam 12, the reflected beam removing unit 220 can have a simple configuration. For example, the predetermined angle can be in the range of 1° to 10° (e.g., 6°). When the predetermined angle is less than 1°, the reflected beam 12 can be emitted toward the laser irradiation unit 210. On the other hand, when the predetermined angle is greater than 10°, immediate heating of a local area can be difficult because the distance between the optical paths of the laser beam 11 and the reflected beam 12 increases, and the overall size of the laser processing apparatus 200 can increase according to the installation position (or the provision position) of the reflected beam removing unit 220.

[0085] In an exemplary embodiment, when the width of the airflow groove 112 is reduced by the laser beam 11 obliquely irradiated at a predetermined angle, the amount of the reflected beam 12 reflected at the bottom surface 112a of the airflow groove 112 can be reduced.

[0086] Figure 5 is a flowchart representing a method for manufacturing a support plate of a chuck table according to another exemplary embodiment.

[0087] Hereinafter, a method for manufacturing a support plate of a chuck table according to another exemplary embodiment will be described in more detail, and features duplicated with those described in the laser processing apparatus according to another exemplary embodiment will be omitted. Figure 5 A method for manufacturing a support plate of a chuck table according to another exemplary embodiment can include a process S100 of preparing a plate-shaped base plate 110a, a process S200 of forming an air flow groove 112 having a depth d smaller than a width w in a surface of the base plate 110a, and a process S300 of forming a suction hole 111 communicating with the air flow groove 112 in the base plate 110a.

[0088] A method for manufacturing a support plate of a chuck table according to another exemplary embodiment can include a process S100 of preparing a plate-shaped base plate 110a, a process S200 of forming an air flow groove 112 having a depth d smaller than a width w in a surface of the base plate 110a, and a process S300 of forming a suction hole 111 communicating with the air flow groove 112 in the base plate 110a.

[0089] First, the plate-shaped base plate 110a is prepared in the process S100. The base plate 110a in which the suction hole 111 and the air flow groove 112 are formed can be prepared, and the support plate 110 of the chuck table 100 is manufactured through the base plate 110a.

[0090] Thereafter, the air flow groove 112 having a depth d smaller than a width w is formed in a surface of the base plate 110a in the process S200. The air flow groove 112 having a depth d smaller than a width w can be formed in the surface of the base plate 110a, and in a top surface of the base plate 110a supporting the processed article 10.

[0091] Since the air flow groove 12 is formed by using the wet etching in the exemplary embodiment, it is important to secure the opening 20a of the pattern mask 20. In the case of the wet etching, when the contact area with the etchant capable of reacting with the etchant is too small, the etching can be difficult to perform since the reaction with the etchant is not sufficiently performed, and thus the air flow groove 112 can be difficult to form. Due to this, the air flow groove 20 must sufficiently secure the opening 20a (i.e., the width of the air flow groove) of about 0.1 mm or more than 0.1 mm of the pattern mask 20 to obtain a sufficient contact area with the etchant capable of reacting with the etchant. However, the air flow groove 112 can have a depth d smaller than the width w since the difference in the reflection characteristics of the bottom surface 112a of the air flow groove 112 and the top surface of the support plate 110 is reduced, and the depth d of the air flow groove 112 must be smaller than about 0.1 mm according to the width w of the air flow groove 112 to prevent the warping of the processed article 10.

[0092] Thereafter, the suction hole 111 communicating with the air flow groove 112 is formed in the base plate 110a in the process S300. The suction hole 111 communicating with the air flow groove 112 can be formed in the base plate 110a. Here, the suction hole 111 can be formed to communicate with the air flow groove 112 after the air flow groove 112 is formed, or the air flow groove 112 communicating with the suction hole 111 can be formed after the suction hole 111 is first formed.

[0093] The process S200 of forming the gas flow groove 112 can include a process S210 of partially wet-etching the surface of the base plate 110a.

[0094] In the process S210, the surface of the base plate 110a can be partially wet-etched. The method for manufacturing a support plate of a chuck table according to an exemplary embodiment can form a gas flow groove 112 having a low depth by wet-etching rather than mechanical processing. Further, according to the wet-etching method, the top surface (upper end surface or support surface) of the support plate 110 can be formed as a curved surface.

[0095] Here, the base plate 110a can be made of metal. In the case of manufacturing the base plate 110a made of ceramic for the support plate 110, the support plate 110 can be worn due to friction with the processed object 10, particles can be easily generated, and damage such as scratches can be generated in the support plate 110 and / or the processed object 10. Due to this, the processed object 10 can not be stably supported. Further, in the exemplary embodiment, the gas flow groove 112 can be formed in the base plate 110a by wet-etching rather than mechanical processing, and the etching rate of the base plate 110a made of ceramic can not be easily controlled. For example, due to an extremely high etching rate, a shallow gas flow groove 112 can not be formed, due to an extremely low etching rate, the formation of the gas flow groove 112 can take a long time, or when etching is performed by forming a pattern mask 20, etching can even be performed in a width direction toward a lower portion of the pattern mask 20, rather than being performed only in a depth direction having directionality. When the support plate 110 is manufactured as described above, the processed object 10 can not be stably supported on the top surface of the support plate 110. For example, the support strength of a portion protruding from the bottom surface 112a of the gas flow groove 112 can be reduced, a pressure difference is generated due to the relatively wide width of the lower portion of the gas flow groove 112, a vacuum can not be properly formed, and air present between the top surface of the support plate 110 and the processed object 10 can not be effectively removed.

[0096] However, when the base plate 110a is made of metal as in the exemplary embodiment, the etching rate can be controlled by adjusting the concentration of an etchant. That is, the etching rate can be easily controlled. Via this, the gas flow groove 112 can have a low depth, and when etching is performed by forming a pattern mask 20, over-etching in the width direction can be limited or prevented by adjusting the time in units of minutes.

[0097] Figure 6 is a view sequentially showing a process of forming a gas flow groove according to another exemplary embodiment. Figure 6 (a) of FIG. 1 shows a process of forming a first pattern mask, Figure 6 (b) of FIG. 1 shows a state after wet-etching is performed by using the first pattern mask,Figure 6 (c) shows the process of forming the second pattern mask. Figure 6 (d) shows the state after wet etching is performed using a second patterned mask, and Figure 6 (e) shows the completed support plate.

[0098] refer to Figure 6 The partial wet etching process S210 may include: forming a pattern mask 20 with an opening 20a on a substrate 110a; providing an etchant to the substrate 110a on which the pattern mask 20 is formed; removing the pattern mask 20; and providing an etchant to the surface of the substrate 110a on which the pattern mask 20 is removed.

[0099] During the formation of the pattern mask 20, a pattern mask 20 with an opening 20a can be formed on the substrate 110a. The pattern mask 20 can be formed to partially wet-etch the surface of the substrate 110a, and the opening 20a can be provided in the portion where wet etching is performed.

[0100] Furthermore, an etchant can be disposed on a base plate 110a, and a pattern mask 20 is formed on the base plate 110a during the process of providing the etchant to the base plate 110a. Here, the etchant can be provided on the base plate 110a on which the pattern mask 20 is formed by immersing it in the etchant, or by spraying the etchant onto the base plate 110a on which the pattern mask 20 is formed. In this way, etching can be performed only in the area exposed by the opening 20a.

[0101] For example, when the substrate 110a is made of aluminum (Al), a mixed solution containing nitric acid (HNO3) and phosphoric acid (H3PO4) can be used as an etchant. Because nitric acid (HNO3) oxidizes aluminum (Al) and phosphoric acid (H3PO4) dissolves aluminum oxide (Al2O3), the substrate 110a can be etched. Acetic acid (CH3COOH) or deionized water (DI water) can be added to the mixed solution, and the etching rate can depend on the concentration of the etchant, temperature, impurities, or mixed materials.

[0102] Subsequently, during the removal of pattern mask 20, pattern mask 20 can be removed. When pattern mask 20 is removed, a base plate 110a in which the airflow groove 112 is formed can be obtained.

[0103] Next, an etchant can be applied to the surface of the substrate 110a. During the application of the etchant to the surface of the substrate 110a, the pattern mask 20 is removed from the surface of the substrate 110a. When etching is performed on the substrate 110a, airflow channels 112 are formed in the substrate 110a without the pattern mask 20. The right-angle corners between the sidewalls of the airflow channels 112 and the top surface (or surface) of the substrate 110a can be gently etched. That is, when etching the entire surface of the substrate 110a in which the airflow channels 112 are formed, the right-angle corners can be gently etched.

[0104] In the partial wet etching process S210, before the process of providing etchant to the surface of the substrate 110a, the process of forming the pattern mask 20, the process of providing etchant to the substrate 110a, and the process of removing the pattern mask 20 can be repeated multiple times. Here, when the process of forming the pattern mask 20 is performed again, a pattern mask 20 with an opening 20a having an area increased compared to the previous process can be formed. For example, when the process of forming the pattern mask 20 is performed again, the pattern mask 20 changes to have an opening 20a having an area increased compared to the previous process. The process of forming the pattern mask 20, the process of providing etchant to the substrate 110a, and the process of removing the pattern mask 20 can be repeated multiple times (i.e., twice or more) to form the sidewalls of the airflow channel 112 into a stepped shape. Furthermore, during the process of providing etchant to the surface of the substrate 110a, the corners of the stepped sidewalls of the airflow channel 112 can be lightly etched to form the top surface of the substrate 110a into a curved surface.

[0105] Here, by repeating the process of forming the pattern mask 20, the opening 20a or pattern gap of the pattern mask 20 can be increased, and by repeating the process of forming the pattern mask 20, the opening gap or pattern width of the pattern mask 20 can be decreased.

[0106] For example, because, as Figure 6 In (a), wet etching is performed by forming a first pattern mask 21 on the base plate 110a, so that it can be performed as follows: Figure 6 In (b), airflow grooves 112 are mainly formed. Then, when wet etching is performed by forming a second pattern mask 22 on the base plate 110a with an opening 20a larger than the opening 20a of the first pattern mask 21, it can be as follows: Figure 6 In (d), a stepped airflow groove 112 is formed for the second time. Subsequently, because the corners of the stepped sidewalls of the airflow groove 112 are gently formed through the entire exposed surface of the etched base plate 110a, a support plate 110 with a curved top surface (or upper surface or support surface) can be manufactured.

[0107] In the process S213 of removing the pattern mask 20 (i.e., the process of removing the first pattern mask), the pattern mask 20 (i.e., the second pattern mask) having an increased area can be provided (or formed) by removing a portion of the pattern mask 20 (i.e., a portion of the first pattern mask).

[0108] Here, the process S211 of forming the pattern mask 20 can be performed by printing a pattern on the base plate 110a. Since the pattern mask is formed by a printing method of printing a pattern, a pattern of a preferred shape can be implemented, and a pattern having a precise pattern gap (or an opening having a small area) can be formed. For example, the pattern mask 20 can be formed by printing a pattern on the base plate 110a using digital printing.

[0109] In the process S212 of providing an etchant on the base plate 110a, the surface of the base plate 110a can be etched in the depth direction by 1 to 50 micrometers. In the process S212 of providing an etchant on the base plate 110a, when the surface of the base plate 110a is etched in the depth direction by more than 50 micrometers, the surface of the base plate 110a is excessively etched even in the width direction toward the lower portion (or downward) of the pattern mask 20, rather than being etched only in the depth direction having directionality. On the other hand, when the surface of the base plate 110a is etched in the depth direction by less than 1 micrometer, since etching is performed on the entire base plate 110a in which the air flow groove 112 is formed without the pattern mask 20, the sidewall of the air flow groove 112 can be removed, and only the curved support surface 115 can remain. In this case, it can not be possible to effectively perform the function of the air flow groove 112.

[0110] A process of further providing a micro-emboss 112b on the bottom surface 112a of the air flow groove 112 can be further provided.

[0111] In the process of forming the micro-emboss 112b, the micro-emboss 112b can be formed on the bottom surface 112a of the air flow groove 112. Here, the micro-emboss 112b can be formed after or before the suction hole 111 is formed. When the micro-emboss 112b is formed on the bottom surface 112a of the air flow groove 112, the micro-emboss 112b can absorb the laser beam 11, and the reflectivity of the laser beam 11 can be reduced by the bottom surface 112a of the air flow groove 112. Accordingly, the difference between the reflection characteristics of the bottom surface 112a of the air flow groove 112 and the top surface of the support plate 110 can be minimized.

[0112] Here, the process of forming the micro-emboss 112b can include a process of forming a micro-pattern mask on the bottom surface 112a of the air flow groove 112, and a process of wet-etching the bottom surface 112a of the air flow groove 112.

[0113] The micro-embossing 112b can be formed by wet-etching a micro-pattern mask (not shown) on the bottom surface 112a of the gas flow groove 112.

[0114] First, in a process of forming a micro-pattern mask on the bottom surface 112a of the gas flow groove 112, the micro-pattern mask can be formed on the bottom surface 112a of the gas flow groove 112. The micro-pattern mask can be formed according to a preferred surface roughness.

[0115] Thereafter, in a process of wet-etching the bottom surface 112a of the gas flow groove 112, the bottom surface 112a of the gas flow groove 112 can be wet-etched. The micro-embossing 112b can be formed by wet-etching a portion exposed by an opening of the micro-pattern mask in the bottom surface 112a of the gas flow groove 112. Through this, the micro-embossing 112b can be simply formed on the bottom surface 112a of the gas flow groove 112. Then, in a process of removing the micro-pattern mask, the micro-pattern mask can be removed after the wet-etching.

[0116] Here, when the micro-pattern mask is formed, in a case where the width w of the gas flow groove 112 is equal to or less than a micro-pattern width (for example, about 0.1 mm) of the micro-pattern mask, the micro-pattern mask only blocks the gas flow groove 112, and the micro-embossing 112b can not be formed.

[0117] The chuck table according to an exemplary embodiment can include a gas flow groove having a minimized depth less than a width thereof. Accordingly, a difference in height between a bottom surface of the gas flow groove and a top surface of a support plate can be reduced. Further, a difference between a reflection characteristic (e.g., reflectivity) of the bottom surface of the gas flow groove and the top surface of the support plate can be reduced. Further, since the depth of the gas flow groove is low, when a vertical direction force of sucking a portion of a processed object (or a substrate) is reduced, warping of the processed object can be prevented. Accordingly, a spot generated in the processed object during a laser process of the processed object can be prevented, and a reduction in process uniformity can be addressed.

[0118] Further, since the micro-embossing is formed on the bottom surface of the gas flow groove, reflectivity (or reflection amount) of a laser beam at the bottom surface of the gas flow groove can be reduced by absorbing the laser beam through the micro-embossing. Accordingly, a difference between the reflection characteristic of the bottom surface of the gas flow groove and the top surface of the support plate can be minimized.

[0119] Further, since a support surface (i.e., a top surface of a support plate) supporting a processed object is formed in a curved shape in the support plate, damage of the processed object and / or generation of particles due to scratching by a corner between a sidewall of a gas flow groove and the top surface of the support plate can be prevented.

[0120] The laser processing apparatus according to exemplary embodiments can tilt a laser beam having a line beam shape at a predetermined angle to irradiate a processed object with the tilted laser beam, thereby preventing an optical system of a laser irradiation unit from being damaged due to a reflected beam of the laser beam reflected at the processed object and / or a support plate being introduced to the laser irradiation unit. In addition, since the irradiated laser beam is tilted at the predetermined angle, the amount of the reflected beam reflected at a bottom surface of the airflow groove can be reduced by reducing the width of the airflow groove.

[0121] The method for manufacturing a support plate of a chuck table according to exemplary embodiments can form an airflow groove having a low depth by wet etching instead of mechanical processing, and form a top surface of the support plate in a curved shape.

[0122] In the description of the embodiments, it will be understood that, when a layer (or film), a region, a pattern, or a structure is referred to as being "on" another layer (or film), region, pad, or pattern, the term "on" includes both a "direct" and an "indirect" in the meaning. It will also be understood that when a layer (or film) is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or an intervening layer can also be present. Thus, the expression "on a base plate" can mean a surface (a top surface or a bottom surface) of the base plate or a surface of a pattern mask disposed on the surface of the base plate.

[0123] While exemplary embodiments of the present application have been described, it is to be understood that the application is not limited to the above-described exemplary embodiments and that various changes and modifications can be suggested to one skilled in the art, all of which are intended to be within the spirit and scope of the application as defined by the appended claims. It is therefore desired that what is claimed be understood merely as an illustrative legal right for the technical scope of the present application.

Claims

1. A chuck table for a laser processing apparatus for irradiating and processing an object to be processed with a laser beam, comprising: a support plate including a suction hole and an air flow groove in communication with the suction hole, and supporting the object to be processed; and a vacuum pump connected to the suction hole to provide a vacuum suction force for fixing the object to be processed, wherein the air flow groove has a depth smaller than a width, wherein the support plate is made of a metal, the air flow groove having a depth of 10 to 100 micrometers is formed by wet etching, wherein the air flow groove includes micro-embossing formed on a bottom surface thereof, and wherein the support plate has a curved support surface, and an arc of the curved support surface has a height of 0.1 to 10 micrometers.

2. The chuck table according to claim 1, wherein the air flow groove has a width of 0.1 to 5 millimeters.

3. The chuck table according to claim 1, wherein the bottom surface of the air flow groove has a surface roughness of 0.01 to 1 micrometer.

4. The chuck table according to claim 1, wherein the object to be processed is optically transmissive.

5. A laser processing apparatus, comprising: the chuck table according to any one of claims 1 to 4; a laser irradiation unit configured to irradiate the object to be processed with a laser beam; and a reflected beam removal unit configured to remove a reflected beam of the laser beam reflected by the object to be processed and the support plate.

6. The laser processing apparatus according to claim 5, wherein the laser irradiation unit obliquely irradiates the laser beam having a line beam shape onto the object to be processed at a predetermined angle.

7. A method for manufacturing a support plate of a chuck table for a laser processing apparatus for irradiating and processing an object to be processed with a laser beam, comprising: preparing a base plate having a plate shape; forming an air flow groove having a depth smaller than a width in a surface of the base plate; forming micro-embossing on a bottom surface of the air flow groove; and forming a suction hole in communication with the air flow groove in the base plate, wherein the forming of the air flow groove includes partially wet-etching the surface of the base plate, wherein the base plate is made of a metal, wherein in the partially wet-etching the surface of the base plate, the air flow groove having a depth of 10 to 100 micrometers is formed by wet etching, and a curved surface having an arc with a height of 0.1 to 10 micrometers is formed on a top surface of the base plate.

8. The method for manufacturing a support plate of a chuck table according to claim 7, wherein the partially wet-etching the surface of the base plate includes: forming a pattern mask having an opening on the base plate; providing an etchant on the base plate on which the pattern mask is formed; removing the pattern mask; and providing the etchant to the surface of the base plate from which the pattern mask is removed. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 9. The method for manufacturing a support plate for a chuck stage according to claim 8, wherein, before providing the etchant to the surface of the base plate, the steps of forming the pattern mask, providing the etchant to the base plate, and removing the pattern mask are repeated multiple times during the partial wet etching of the surface of the base plate. When the process of forming the pattern mask is performed again, a pattern mask with an opening having an area increased compared to the previous process is formed.

10. The method for manufacturing a support plate for a chuck worktable according to claim 8, wherein the formation of the pattern mask is performed by printing a pattern on the base plate.

11. The method of manufacturing a support plate for a chuck worktable according to claim 8, wherein when the etchant is provided on the base plate, the surface of the base plate is etched from 1 micrometer to 50 micrometers.

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