Bipolar electrostatic chuck for holding large area substrates

Abstract

A bipolar electrostatic chuck is disclosed. The bipolar electrostatic chuck includes: a base; a lower dielectric layer formed on the entire upper surface of the base; an edge electrode portion formed on the upper side of the lower dielectric layer along an edge, the edge electrode portion including a first electrode and a second electrode, the second electrode being separated from the first electrode and having a polarity different from that of the first electrode; and an upper dielectric layer formed on the upper side of the lower dielectric layer and the edge electrode portion, wherein in a plan view, the bipolar electrostatic chuck is divided into an edge electrode forming region and a central region, the edge electrode forming region corresponding to a region from the edge to the edge electrode portion, and the central region corresponding to a region other than the edge electrode forming region.

Description

Technical Field

[0001] The present disclosure relates to bipolar electrostatic chucks, and more particularly, to bipolar electrostatic chucks that use electrostatic forces to hold large area substrates. Background Art

[0002] A wafer or substrate (e.g., a glass substrate) as an object to be processed is subjected to various processing procedures such as etching, CVD, sputtering, ion implantation, ashing, and / or evaporation deposition in the process of manufacturing a semiconductor, a display panel, or the like. In this case, it is necessary to stably hold the object to be processed, and a mechanical chuck or a vacuum chuck can be used for this purpose, but an electrostatic chuck is also widely used.

[0003] An electrostatic chuck (ESC) uses electrostatic force between two objects having different potentials. A conventional general electrostatic chuck is configured to have a structure including a metal plate, a dielectric layer stacked on an upper side of the metal plate via an organic adhesive such as silicone resin, and electrodes formed in the dielectric layer.

[0004] An electrostatic chuck in which an electrode of a single polarity is formed in a dielectric layer is called a monopolar electrostatic chuck (monopolar ESC or unipolar ESC), and an electrostatic chuck in which electrodes have two polarities different from each other is called a bipolar electrostatic chuck (bipolar ESC).

[0005] Meanwhile, as wafers or glass substrates have become larger recently, electrostatic chucks have also become larger, and a method of forming a dielectric layer and an electrode by plasma spraying has been used in the manufacture of the electrostatic chuck.

[0006] The clamping force is one of the first factors to be considered in manufacturing an electrostatic chuck. When the supplied electrical energy (the amount of charge accumulated) is the same, the electrostatic force increases as the area of ​​the electrode increases. Therefore, in conventional electrostatic chucks, the electrodes are made to occupy a large proportion of the total area of ​​the electrostatic chuck.

[0007] This tendency occurs in both conventional monopolar electrostatic chucks and bipolar electrostatic chucks. Specifically, in a bipolar electrostatic chuck, electrodes are formed over the total area of ​​the electrostatic chuck, and this tendency becomes more pronounced.

[0008] However, as the area of ​​the electrostatic chuck becomes larger, when the proportion and location of the area where the electrode is formed are not carefully considered, the overall cost of manufacturing the electrostatic chuck increases and an inappropriately large clamping force that may cause damage to the wafer or substrate may be applied to the wafer or substrate.

[0009] Furthermore, when a substrate is processed using an electrostatic chuck having a large area, there is a high possibility that contamination occurs due to temperature deviation or potential difference in a processing chamber, and there is a need to develop an electrostatic chuck that can solve this problem.

[0010] Prior art documents

[0011] Patent Document 1: Korean Patent No. 10-1797927 (registered on November 9, 2017).

[0012] Patent Document 2: Korean Patent No. 10-1775135 (registered on August 30, 2017). Summary of the invention

[0013] Technical issues

[0014] The invention of the present disclosure is to provide a bipolar electrostatic chuck that can provide adequate holding force while reducing manufacturing costs and avoiding contamination on substrates during substrate handling processes.

[0015] Technical Solution

[0016] In order to achieve the invention described above, a bipolar electrostatic chuck for holding a large-area substrate is provided, specifically wherein each side of the large-area substrate has a size of 2000 mm or more. The bipolar electrostatic chuck may include: a base; a lower dielectric layer formed on an upper surface of the base, specifically the entire upper surface of the base; an edge electrode portion formed on an upper side of the lower dielectric layer along a rim, the edge electrode portion including a first electrode and a second electrode, the second electrode being separated from the first electrode and having a polarity different from that of the first electrode; and an upper dielectric layer formed on an upper side of the lower dielectric layer and the edge electrode portion, wherein, in a plan view, the bipolar electrostatic chuck is divided into an edge electrode forming region and a central region, the edge electrode forming region corresponding to a region from a corner to the edge electrode portion, and the central region corresponding to a region other than the edge electrode forming region.

[0017] In the bipolar electrostatic chuck according to the present disclosure, the area (A) of the edge electrode forming region may be in the range of 20% to 35% of the total area of ​​the bipolar electrostatic chuck.

[0018] The bipolar electrostatic chuck according to the present disclosure may further include a central electrode portion formed in the exact center on the upper side of the lower dielectric layer and including a third electrode and a fourth electrode, the fourth electrode being separated from the third electrode and having a polarity different from that of the third electrode, wherein the upper dielectric layer may be formed on the upper side of the lower dielectric layer, the edge electrode portion, and the central electrode portion, and in a plan view, an area (B) of a central electrode forming region defined by an outer boundary of the central electrode portion may be in the range of 2% to 5% of the total area of ​​the bipolar electrostatic chuck.

[0019] In the bipolar electrostatic chuck according to the present disclosure, when the total area is in the range of 2200 mm*2500 mm to 3100 mm*3400 mm, the edge electrode forming region may have a width of 200 mm, and the center electrode forming region may have an area of ​​300 mm*300 mm.

[0020] In a bipolar electrostatic chuck according to the present disclosure, the upper dielectric layer may include a first upper dielectric layer formed on an edge electrode portion, and a second upper dielectric layer connected to the lower dielectric layer in a central region, and the first upper dielectric layer may have a higher dielectric constant than that of the second upper dielectric layer, or have a smaller specific resistance value than that of the second upper dielectric layer.

[0021] In a bipolar electrostatic chuck according to the present disclosure, the upper dielectric layer may include a first upper dielectric layer formed on an edge electrode portion, a second upper dielectric layer connected to the lower dielectric layer in a central region, and a third dielectric layer formed on an upper side of the central electrode portion, wherein the first upper dielectric layer and the third upper dielectric layer have a higher dielectric constant than that of the second upper dielectric layer, or have a lower specific resistance value than that of the second upper dielectric layer.

[0022] In a bipolar electrostatic chuck according to the present disclosure, the upper dielectric layer may include a fourth upper dielectric layer connected to the lower dielectric layer in a central region, and a fifth upper dielectric layer formed on an edge electrode portion and an upper side of the fourth upper dielectric layer, wherein the fifth upper dielectric layer may have a higher dielectric constant than that of the fourth upper dielectric layer, or have a smaller specific resistance value than that of the fourth upper dielectric layer.

[0023] In a bipolar electrostatic chuck according to the present disclosure, the upper dielectric layer may include a fourth upper dielectric layer connected to the lower dielectric layer in a central region, and a sixth upper dielectric layer formed on an edge electrode portion, a central electrode portion, and an upper side of the fourth upper dielectric layer, wherein the sixth upper dielectric layer may have a higher dielectric constant than that of the fourth upper dielectric layer, or have a smaller specific resistance value than that of the fourth upper dielectric layer.

[0024] In a bipolar electrostatic chuck according to the present disclosure, the upper dielectric layer may include a first recessed portion serving as a boundary between an edge electrode forming region and a central region and having a recessed upper surface, and a second recessed portion extending across the central region and having a recessed upper surface.

[0025] In a bipolar electrostatic chuck according to the present disclosure, the upper dielectric layer may include a first recessed portion, which serves as a boundary between an edge electrode forming region and a central region and has a recessed upper surface, a second recessed portion, which extends across the central region and has a recessed upper surface, and a third recessed portion, which serves as a boundary between the central region and a central electrode forming region and has a recessed upper surface.

[0026] In a bipolar electrostatic chuck according to the present disclosure, the second upper dielectric layer may be formed of Al2O3, and the first upper dielectric layer and the third upper dielectric layer are formed of Al2O3 with at least one particle selected from the group consisting of TiC, TiO2, Cr2O3, MnO2, COC, and CuO added.

[0027] In the bipolar electrostatic chuck according to the present disclosure, the first upper dielectric layer, the second upper dielectric layer, and the third upper dielectric layer may have a surface roughness (Ra) of 2 to 3.5 μm or 0.8 μm.

[0028] Technical Effects

[0029] According to the present disclosure, it is possible to provide a bipolar electrostatic chuck capable of optimizing functions while reducing manufacturing costs, and capable of avoiding contamination due to temperature changes or potential differences during a process of manufacturing a substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1A is a plan view schematically illustrating a bipolar electrostatic chuck according to an embodiment of the present disclosure;

[0031] Figure 1B It is a cross-sectional view, schematically illustrating Figure 1A Bipolar electrostatic chuck;

[0032] Figure 2A is a plan view schematically illustrating a bipolar electrostatic chuck according to another embodiment of the present disclosure;

[0033] Figure 2B It is a cross-sectional view, schematically illustrating Figure 2A Bipolar electrostatic chuck;

[0034] Figure 3A and 3B is a cross-sectional view schematically illustrating a bipolar electrostatic chuck according to yet another embodiment of the present disclosure; Figure 4A is a perspective view schematically illustrating a bipolar electrostatic chuck according to yet another embodiment of the present disclosure;

[0035] Figure 4B It is a cross-sectional view, schematically illustrating Figure 4A Bipolar electrostatic chuck;

[0036] Figure 5A is a perspective view schematically illustrating a bipolar electrostatic chuck according to yet another embodiment of the present disclosure;

[0037] Figure 5B It is a cross-sectional view, schematically illustrating Figure 5A Bipolar electrostatic chuck.

[0038] Description of Reference Numerals

[0039] 1: Bipolar electrostatic chuck, 10: Base,

[0040] 20: lower dielectric layer, 30: edge electrode part,

[0041] 31: first electrode, 32: second electrode,

[0042] 40: central electrode portion; 41: third electrode; 42: fourth electrode; 50: upper dielectric layer; 51: first upper dielectric layer; 52: second upper dielectric layer;

[0043] 53: a third upper dielectric layer, 54: a fourth upper dielectric layer,

[0044] 55: fifth upper dielectric layer, 56: sixth upper dielectric layer,

[0045] 57: first recessed portion; 58: second recessed portion; 59: third recessed portion; T1: edge electrode forming region;

[0046] T2: Central electrode formation area, T3: Central area DETAILED DESCRIPTION

[0047] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, in the following description of the present disclosure, descriptions of known functions or configurations will be omitted in order to clarify the gist of the present disclosure.

[0048] Figure 1A and Figure 1B Show floor plan ( Figure 1A ) and cross-sectional view ( Figure 1B ), schematically illustrating a bipolar electrostatic chuck 1 according to an embodiment of the present disclosure, and Figure 2A and Figure 2B Show floor plan ( Figure 2A ) and cross-sectional view ( Figure 2B ), schematically illustrating a bipolar electrostatic chuck 1 according to another embodiment of the present disclosure.

[0049] Figures 1A to 2B The above is a summary and partly exaggerated to facilitate the description of the technical features of the bipolar electrostatic chuck 1 according to the present disclosure, and the FIG. 3A to FIG. 5BThe bipolar electrostatic chuck 1 according to the present disclosure has the technical features described in the present disclosure, and can of course be formed in various shapes, patterns, specifications, and the like.

[0050] According to the present disclosure regarding the electrostatic chuck 1, the bipolar electrostatic chuck has electrodes on a portion of the bipolar electrostatic chuck (hereinafter referred to as the "bipolar electrostatic chuck 1"), and is configured to use electrostatic force to hold a wafer or substrate of an object to be processed in a process of manufacturing a semiconductor or a display panel, and is suitable for holding a large-area substrate bipolar electrostatic chuck 1, particularly for holding a large-area substrate constituting an organic light emitting diode (OLED) display panel.

[0051] The bipolar electrostatic chuck 1 according to the present disclosure includes a base 10, a lower dielectric layer 20, electrode portions (edge ​​electrode portion 30 and center electrode portion 40), and an upper dielectric layer 50. Hereinafter, the side formed by the base 10 will be referred to as the lower side, and the side formed by the upper dielectric layer 50 will be referred to as the upper side.

[0052] A bipolar electrostatic chuck 1 according to the present disclosure may include a base 10, a lower dielectric layer 20, an edge electrode portion 30, and an upper dielectric layer 50 (see FIG. Figure 1B ), each of which is laminated in a vertical direction. Alternatively, the bipolar electrostatic chuck 1 may include a base 10, a lower dielectric layer 20, an edge electrode portion 30, a center electrode portion 40 and an upper dielectric layer 50 (see Figure 2B ), each of which is laminated in a vertical direction.

[0053] In recent years, the demand for large area displays has steadily increased, and an increase in the size of glass substrates is also required in order to improve the chamfering rate during the manufacture of display panels. The size of substrates used to manufacture display panels can be classified by generation. For example, a substrate for an 8th generation panel may have a size of 2200 mm*2500 mm, a substrate for a 10th generation panel may have a size of 2940*3340 mm, and a substrate for an 11th generation panel may have a size of 3000*3320 mm.

[0054] The bipolar electrostatic chuck 1 of the present disclosure for holding such a large-area substrate S (a substrate having a length of 2000 mm or more on each side) also needs to be large, and in plan view, the total area (see Figure 1A and Figure 2A ) may have a size of 2200mm*2500mm or more (d1*d2), or the total area may be in the range of 2200mm*2500mm to 3100mm*3400mm. Specifically, the bipolar electrostatic chuck 1 of the present disclosure may have a size of 2980mm*3280mm.

[0055] The base 10 can be made of various materials to ensure sufficient mechanical rigidity, and is preferably made of metal material. Specifically, the base 10 can be made of aluminum, stainless steel or the like. The base 10 is in the form of a rectangular plate as a whole.

[0056] The lower dielectric layer 20 may be formed on the entire upper surface of the base 10, and may be laminated and bonded to the base 10. The lower dielectric layer 20 forms an insulating layer between the base 10 and the electrode portion (the edge electrode portion 30 and the center electrode portion 40). The lower dielectric layer 20 may be formed of various dielectric materials having insulating properties, and may be formed of a ceramic material. In this case, the lower dielectric layer 20 may be formed on the upper surface of the base 10 through a plasma spraying method, a sol-gel method, or the like. More specifically, the lower dielectric layer 20 may be made of a material selected from or in combination of: Al2O3, Y2O3, ZrO2, MgO, SiC, AlN, Si3N4, and SiO2. Specifically, the lower dielectric layer 20 may be made of Al2O3.

[0057] The edge electrode portion 30 may be made of a conductor, specifically tungsten. The edge electrode portion 30 is electrically connected to a separately provided DC power supply. The formation of the DC power supply and the connection of the DC power supply to the electrode portions (edge ​​electrode portion 30 and center electrode portion 40) may be implemented by various known methods.

[0058] The edge electrode portion 30 is divided into a first electrode 31 and a second electrode 32, which are separated from each other and can have different polarities during power supply by a DC power supply. That is, when a positive (+) polarity is applied to the first electrode 31, a negative (-) polarity is applied to the second electrode 32.

[0059] The edge electrode portion 30 is formed on the upper side of the lower dielectric layer 20, and may be formed by plasma spraying or the like. In this case, the first electrode 31 and the second electrode 32 forming the edge electrode portion 30 may be formed by various known patterns.

[0060] The upper dielectric layer 50 is formed on the upper side of the lower dielectric layer 20 and the edge electrode 30, and is laminated and bonded to the lower dielectric layer 20 and the edge electrode portion 30. The upper dielectric layer 50 constitutes the entire upper surface of the bipolar electrostatic chuck 1, and the upper surface of the upper dielectric layer 50 is in contact with the substrate S. As the upper dielectric layer 50 is formed, the edge electrode portion 30 is buried between the lower dielectric layer 20 and the upper dielectric layer 50.

[0061] The upper dielectric layer 50 may be formed of various dielectric materials having insulating properties, and may be formed of a ceramic material. In this case, the upper dielectric layer 50 may be formed on the upper side of the lower dielectric layer 20 and the edge electrode portion 30 by a plasma spraying method, a sol-gel method, or the like. The upper dielectric layer 50 may be made of the same material as the lower dielectric layer 20 and by the same method.

[0062] The upper dielectric layer 50 is preferably formed to have a uniform deposition height and surface roughness over its entire area. Specifically, the surface roughness Ra of the upper dielectric layer 50 may have any value in the range of 2 to 3.5 μm, or have a value of 0.8 μm.

[0063] In the present disclosure, the edge electrode portion 30 is not formed on the entire area of ​​the bipolar electrostatic chuck 1, but is formed in a partial area, specifically, along the rim of the electrostatic chuck 1. In a plan view (that is, when the bipolar electrostatic chuck 1 is viewed from above), the edge electrode portion 30 is formed only in the rim portion of the bipolar electrostatic chuck 1, and not in the central portion of the bipolar electrostatic chuck.

[0064] Therefore, in the present disclosure, the bipolar electrostatic chuck 1 can be divided into an edge electrode forming region T1, in which the edge electrode portion 30 is formed from the edge of the bipolar electrostatic chuck 1, and a central region T3 excluding the edge electrode forming region T1, and a boundary b1 is formed between the edge electrode forming region T1 and the central region T3.

[0065] The area (A) of the edge electrode forming region T1 may be set to satisfy a range of 20% to 35% of the total area of ​​the bipolar electrostatic chuck 1 , and the width d3 of the edge electrode forming region T1 may be fixed along the entire edge of the bipolar electrostatic chuck 1 .

[0066] In the present disclosure, when the total area (d1*d2) of the bipolar electrostatic chuck is 2200mm*2500mm to 3100mm*3400mm, the edge electrode forming region T1 is formed to have a predetermined width d3 of 200mm along the edge of the bipolar electrostatic chuck 1 .

[0067] Under the configuration described above, in the bipolar electrostatic chuck 1 according to the present disclosure, electrostatic force can be quickly generated along the edge portion without generating a potential difference, and when clamping the substrate S, a uniform and stable clamping force is applied along the edge portion of the substrate S.

[0068] As described above, since the electrodes are not formed on the entire area of ​​the bipolar electrostatic chuck 1 in the present disclosure, it is possible to provide an appropriate holding force while reducing manufacturing costs. It is also possible to avoid temperature deviation or potential difference, so that stains on the substrate S can be effectively avoided.

[0069] Meanwhile, as described above, the bipolar electrostatic chuck 1 according to the present disclosure may further include a center electrode portion 40 in addition to the edge electrode portion 30. In this case, the base 10, the lower dielectric layer 20, the edge electrode portion 30, and the upper dielectric layer 50 may be made of the same material and by the same method as described above. However, the upper dielectric layer 50 is formed on the upper side of the lower dielectric layer 20, the edge electrode portion 30, and the center electrode portion 40 (see FIG. Figure 2B ), and is laminated on and bonded to the lower dielectric layer 20, the edge electrode portion 30 and the center electrode portion 40.

[0070] The edge electrode portion 30 and the center electrode portion 40 are embedded between the lower dielectric layer 20 and the upper dielectric layer 50 .

[0071] The central electrode portion 40 is preferably formed in the center on the upper side of the lower dielectric layer 20, and may be made of a conductor, specifically tungsten. The central electrode portion 40 is electrically connected to a DC power source.

[0072] The central electrode portion 40 is divided into a third electrode 41 and a fourth electrode 42, which are separated from each other and have different polarities during power supply by a DC power source. That is, when a positive (+) polarity is applied to the third electrode 41, a negative (-) polarity is applied to the fourth electrode 42.

[0073] The central electrode portion 40 is formed on the upper side of the lower dielectric layer 20, and may be formed by plasma spraying or the like. In this case, the third electrode 41 and the fourth electrode 42 forming the central electrode portion 40 may be formed by various known patterns.

[0074] In a plan view, the area (B) of the center electrode forming region T2 defined by the outer boundary b2 of the center electrode portion 40 may be set to satisfy a range of 2% to 5% of the total area (d1*d2) of the bipolar electrostatic chuck 1.

[0075] In the present disclosure, when the total area of ​​the bipolar electrostatic chuck 1 is 2200 mm*2500 mm to 3100 mm*3400 mm, the central electrode forming region T2 ( d4 * d5 ) may be set to have a size of 300 mm*300 mm in the center of the bipolar electrostatic chuck 1 .

[0076] Under this configuration, in the bipolar electrostatic chuck 1 according to the present disclosure, a uniform and stable clamping force is applied along the edge of the substrate S during clamping of the substrate S. In addition, the auxiliary clamping force acts on the central portion of the substrate S, so that the substrate S can be fixed more stably.

[0077] In this case, it is also possible to avoid the occurrence of temperature deviation or potential difference, so that the occurrence of stains on the substrate S during the substrate processing process can be effectively avoided.

[0078] Figure 3A and Figure 3B A cross-sectional view is shown, schematically illustrating a bipolar electrostatic chuck 1 according to another embodiment of the present disclosure. When the bipolar electrostatic chuck 1 according to the present disclosure includes a base 10, a lower dielectric layer 20, an edge electrode portion 30, and an upper dielectric layer 50, the upper dielectric layer 50 may be divided into a first upper dielectric layer 51 and a second upper dielectric layer 52 (see FIG. Figure 3A ).

[0079] The first upper dielectric layer 51 is a portion formed on the edge electrode portion 30 , and the second upper dielectric layer 52 is a portion connected to the lower dielectric layer 20 in the center region T3 .

[0080] Each of the first upper dielectric layer 51 and the second upper dielectric layer 52 may be formed of a dielectric material having insulating properties and may be formed of a ceramic material. In this case, the first upper dielectric layer 51 and the second upper dielectric layer 52 may be formed by a plasma welding method, a sol-gel method, or the like.

[0081] The first upper dielectric layer 51 and the second upper dielectric layer 52 are formed separately, and preferably one is formed first and then the other. Of course, after forming the first upper dielectric layer 51 and the second upper dielectric layer 52, separate surface treatments may be performed to ensure a constant height and surface roughness Ra of the entire upper dielectric layer 50.

[0082] In the bipolar electrostatic chuck 1 according to the present disclosure, the first upper dielectric layer 51 may have a higher dielectric constant than the second upper dielectric layer 52, or have a smaller specific resistance value than the second upper dielectric layer 52. The second upper dielectric layer 52 may be made of Al2O3, Y2O3, ZrO2, MgO, SiC, AlN, Si3N4, SiO2, etc., and the first upper dielectric layer 51 may be made of particles formed of at least one of TiC, TiO2, Cr2O3, MnO2, CoC, and CuO added to a base material such as Al2O3, Y2O3, ZrO2, MgO, SiC, AlN, Si3N4, or SiO2. Preferably, the second upper dielectric layer 52 may be made of Al 2 O 3 , and the first upper dielectric layer 51 may be made of Al 2 O 3 to which particles of at least one of TiC, TiO 2 , Cr 2 O 3 , MnO 2 , CoC, and CuO are added.

[0083] Meanwhile, when the bipolar electrostatic chuck 1 according to the present disclosure includes the base 10, the lower dielectric layer 20, the edge electrode portion 30, the center electrode portion 40, and the upper dielectric layer 50, the upper dielectric layer 50 may be divided into a first upper dielectric layer 51, a second upper dielectric layer 52, and a third upper dielectric layer 53 (see FIG. Figure 3B ).

[0084] Here, the first upper dielectric layer 51 is a portion formed on the edge electrode portion 30 , the third upper dielectric layer 53 is a portion formed on the center electrode portion 40 , and the second upper dielectric layer 52 is a portion connected to the lower dielectric layer 20 in the center region T3 .

[0085] Each of the first upper dielectric layer 51, the second upper dielectric layer 52, and the third upper dielectric layer 53 may be formed of a dielectric material having an insulating property, and may be formed of a ceramic material. In this case, the first upper dielectric layer 51, the second upper dielectric layer 52, and the third upper dielectric layer 53 may be formed by a plasma welding method, a sol-gel method, or the like.

[0086] The first upper dielectric layer 51, the second upper dielectric layer 52, and the third upper dielectric layer 53 may be formed separately. However, it is preferred to form the first upper dielectric layer 51 and the third upper dielectric layer 53 together. Of course, after forming the first upper dielectric layer 51, the second upper dielectric layer 52, and the third upper dielectric layer 53, separate surface treatments may be performed to ensure a constant height and surface roughness Ra of the upper dielectric layer 50.

[0087] In the bipolar electrostatic chuck 1 according to the present disclosure, the first upper dielectric layer 51 and the third upper dielectric layer 53 may have a higher dielectric constant than the second upper dielectric layer 52, or have a smaller specific resistance value than the second upper dielectric layer 52. The second upper dielectric layer 52 may be made of Al2O3, Y2O3, ZrO2, MgO, SiC, AlN, Si3N4, SiO2, etc., and the first upper dielectric layer 51 and the third upper dielectric layer 53 may be made of particles formed of at least one of TiC, TiO2, Cr2O3, MnO2, CoC, and CuO added to a base material such as Al2O3, Y2O3, ZrO2, MgO, SiC, AlN, Si3N4, or SiO2. Preferably, the second upper dielectric layer 52 may be made of Al 2 O 3 , and the first upper dielectric layer 51 and the third upper dielectric layer 53 may be made of Al 2 O 3 to which particles of at least one of TiC, TiO 2 , Cr 2 O 3 , MnO 2 , CoC, and CuO are added.

[0088] Under this configuration, the electrostatic force in the edge electrode forming area T1 (or the edge electrode forming area T1 and the center electrode forming area T2) can be increased under the same power supply and electrode conditions, the possibility of charge accumulation due to leakage current in the center area T3 (the center area T3 excluding the center electrode forming area T2 when the center electrode forming area T2 is provided) can be reduced, and the clamping and release of the substrate S can be carried out more stably and effectively.

[0089] Figure 4A and Figure 4B Display Stereograph( Figure 4A ) and cross-sectional view ( Figure 4B ), schematically illustrating a bipolar electrostatic chuck 1 according to yet another embodiment of the present disclosure, and Figure 5A and Figure 5B Display Stereograph( Figure 5A ) and cross-sectional view ( Figure 5B ), according to yet another embodiment of the present disclosure, a bipolar electrostatic chuck 1 is schematically illustrated.

[0090] When the bipolar electrostatic chuck 1 according to the present disclosure includes the base 10, the lower dielectric layer 20, the edge electrode portion 30 and the upper dielectric layer 50, the upper dielectric layer 50 may be divided into a fourth upper dielectric layer 54 and a fifth upper dielectric layer 55 (see Figure 4A and Figure 4B ).

[0091] At this time, the upper dielectric layer 50 may further include a first recessed portion 57 and a second recessed portion 58 .

[0092] The fourth upper dielectric layer 54 is a portion connected to the lower dielectric layer 20 in the central region T3 , and the fifth upper dielectric layer 55 is a portion formed on the upper side of the edge electrode portion 30 and the fourth upper dielectric layer 54 .

[0093] Each of the fourth upper dielectric layer 54 and the fifth upper dielectric layer 55 may be formed of a dielectric material having insulating properties and may be formed of a ceramic material. In this case, the fourth upper dielectric layer 54 and the fifth upper dielectric layer 55 may be formed by a plasma welding method, a sol-gel method, or the like.

[0094] Of course, the fifth upper dielectric layer 55 is formed after forming the fourth upper dielectric layer 54 , and preferably forms the fourth upper dielectric layer 54 to have a height that is the same as or higher than the edge electrode portion 30 .

[0095] In the bipolar electrostatic chuck 1 according to the present disclosure, the fifth upper dielectric layer 55 may have a higher dielectric constant than the fourth upper dielectric layer 54, or have a smaller specific resistance value than the fourth upper dielectric layer 54. The fourth upper dielectric layer 54 may be made of Al4O5, Y2O3, ZrO2, MgO, SiC, AlN, Si3N4, SiO2, etc., and the fifth upper dielectric layer 55 may be made of particles formed of at least one of TiC, TiO2, Cr2O3, MnO2, CoC, and CuO added to a base material form such as Al2O3, Y2O3, ZrO2, MgO, SiC, AlN, Si3N4, or SiO2. Preferably, the fourth upper dielectric layer 54 may be made of Al 2 O 3 , and the fifth upper dielectric layer 55 may be made of Al 2 O 3 to which particles of at least one of TiC, TiO 2 , Cr 2 O 3 , MnO 2 , CoC, and CuO are added.

[0096] The first recessed portion 57 forms a boundary between the edge electrode forming region T1 and the central region T3, and forms a shape of a recessed groove in the upper surface of the upper dielectric layer 50. The first recessed portion 57 is preferably formed to extend to the upper end surface of the fourth upper dielectric layer 54, and along the first recessed portion 57, the fifth upper dielectric layer 55 is physically divided into a portion of the edge electrode forming region T1 and a portion of the central region T3.

[0097] The second recessed portion 58 extends across the central region T3 and forms a shape of a recessed trench in the upper surface of the upper dielectric layer 50 .

[0098] Furthermore, when the bipolar electrostatic chuck 1 according to the present disclosure includes the base 10, the lower dielectric layer 20, the edge electrode portion 30, the center electrode portion 40, and the upper dielectric layer 50, the upper dielectric layer 50 may be divided into a fourth upper dielectric layer 54 and a sixth upper dielectric layer 56 (see Figure 5A and Figure 5B ).

[0099] At this time, the upper dielectric layer 50 may further include a first recessed portion 57 , a second recessed portion 58 , and a third recessed portion 59 .

[0100] As described above, the fourth upper dielectric layer 54 is a portion connected to the lower dielectric layer 20 in the central region T3 , and the sixth upper dielectric layer 56 is a portion formed on the edge electrode portion 30 , the central electrode portion 40 , and the upper side of the fourth upper dielectric layer 54 .

[0101] Each of the fourth upper dielectric layer 54 and the sixth upper dielectric layer 56 may be formed of a dielectric material having insulating properties and may be formed of a ceramic material. In this case, the fourth upper dielectric layer 54 and the sixth upper dielectric layer 56 may be formed by a plasma welding method, a sol-gel method, or the like.

[0102] Of course, the sixth upper dielectric layer 56 is formed after forming the fourth upper dielectric layer 54 , and preferably forms the fourth upper dielectric layer 54 having a height that is the same as or higher than the heights of the edge electrode portion 30 and the center electrode portion 40 .

[0103] In the bipolar electrostatic chuck 1 according to the present disclosure, the sixth upper dielectric layer 56 may have a higher dielectric constant than the fourth upper dielectric layer 54, or have a smaller specific resistance value than the fourth upper dielectric layer 54, and the sixth upper dielectric layer 56 may be made of the same material as the fifth upper dielectric layer 55 as described above.

[0104] The first recessed portion 57 forms a boundary between the edge electrode forming region T1 and the central region T3, and forms a shape of a recessed groove in the upper surface of the upper dielectric layer 50. The first recessed portion 57 is preferably formed to extend to the upper end surface of the fourth upper dielectric layer 54, and along the first recessed portion 57, the sixth upper dielectric layer 56 is physically divided into a portion of the edge electrode forming region T1 and a portion of the central region T3.

[0105] The second recessed portion 58 extends across the central region T3 and forms a shape of a recessed trench in the upper surface of the upper dielectric layer 50 .

[0106] The third recessed portion 59 forms a boundary between the central region T3 and the central electrode forming region T2, and forms a shape of a recessed groove in the upper surface of the upper dielectric layer 50. The third recessed portion 59 is preferably formed so as to extend to the upper end surface of the fourth upper dielectric layer 54, and along the third recessed portion 59, the sixth upper dielectric layer 56 is physically divided into a portion of the central region T3 and a portion of the central electrode forming region T2.

[0107] Under this configuration, the electrostatic force in the edge electrode forming area T1 (or the edge electrode forming area T1 and the center electrode forming area T2) can be improved under the same power supply and electrode conditions, the possibility of charge accumulation due to leakage current in the center area T3 (the center area T3 excluding the center electrode forming area T2 when the center electrode forming area T2 is provided) can be reduced, and the clamping and release of the substrate S can be carried out more efficiently.

[0108] Because the upper dielectric layer 50 includes the first recessed portion 57 and the second recessed portion 58, or includes the first recessed portion 57, the second recessed portion 58 and the third recessed portion 59, stains due to temperature changes can be more effectively avoided, and the recessed portions can help the smooth movement of the insulating gas such as helium filling in the space between the substrate S and the bipolar electrostatic chuck 1.

[0109] Although specific embodiments of the present disclosure have been described and illustrated above, it is obvious to those skilled in the art that the present disclosure is not limited to the disclosed embodiments, and various changes and modifications may be made without departing from the technical concept and scope of the present disclosure. Therefore, such modifications and changes should not be understood as being separated from the technical spirit and view of the present disclosure, and the modifications and changes should be regarded as falling within the scope of the claims of the present disclosure.

[0110] Industrial Applicability

[0111] According to the bipolar electrostatic chuck having electrodes on a portion of the bipolar electrostatic chuck of the present disclosure, it is possible to provide a bipolar electrostatic chuck having optimized functions of reducing manufacturing costs and being able to avoid stains due to temperature changes or potential differences during the manufacturing process of the substrate. In this viewpoint, because the present disclosure overcomes the limitations of the prior art, the device to which the present disclosure is applied has the opportunity to be commercially available or to be sold without being limited to the device of the related art using the present disclosure. Furthermore, it is obviously possible to implement the present disclosure in reality. Therefore, the present disclosure can be used in industry.

Claims

1. A bipolar electrostatic chuck for holding a large area substrate, each side of the large area substrate having a size of 2000 mm or more, the bipolar electrostatic chuck comprising: Base; a lower dielectric layer formed on the entire upper surface of the base; an edge electrode portion formed on an upper side of the lower dielectric layer along an edge, the edge electrode portion including a first electrode and a second electrode, the second electrode being spaced apart from the first electrode and having a polarity different from that of the first electrode; a central electrode portion formed in the center on the upper side of the lower dielectric layer and including a third electrode and a fourth electrode, the fourth electrode being spaced apart from the third electrode and having a polarity different from that of the third electrode; and an upper dielectric layer formed on an upper side of the lower dielectric layer, the edge electrode portion, and the center electrode portion, in, In a plan view, the bipolar electrostatic chuck is divided into an edge electrode forming region and a central region, the edge electrode forming region corresponds to a region from an edge to the edge electrode portion, and the central region corresponds to a region other than the edge electrode forming region, and an area (A) of the edge electrode forming region is in a range of 20% to 35% of a total area of ​​the bipolar electrostatic chuck, wherein in the plan view, an area (B) of a center electrode forming region defined by an outer boundary of the center electrode portion is in a range of 2% to 5% of the total area of ​​the bipolar electrostatic chuck.

2. The bipolar electrostatic chuck of claim 1 , wherein the upper dielectric layer comprises: a first upper dielectric layer formed on the edge electrode portion; and a second upper dielectric layer connected to the lower dielectric layer in the central region, and The first upper dielectric layer has a higher dielectric constant than that of the second upper dielectric layer, or has a smaller specific resistance than that of the second upper dielectric layer.

3. The bipolar electrostatic chuck of any one of claims 1 or 2, wherein the upper dielectric layer comprises: a fourth upper dielectric layer connected to the lower dielectric layer in the central region; and a fifth upper dielectric layer formed on the edge electrode portion and the upper side of the fourth upper dielectric layer, The fifth upper dielectric layer has a higher dielectric constant than that of the fourth upper dielectric layer, or has a smaller specific resistance than that of the fourth upper dielectric layer.

4. A bipolar electrostatic chuck for holding a large area substrate, each side of the large area substrate having a size of 2000 mm or more, the bipolar electrostatic chuck comprising: Base; a lower dielectric layer formed on the entire upper surface of the base; an edge electrode portion formed on an upper side of the lower dielectric layer along an edge, the edge electrode portion including a first electrode and a second electrode, the second electrode being spaced apart from the first electrode and having a polarity different from that of the first electrode; a central electrode portion formed in the center on the upper side of the lower dielectric layer and including a third electrode and a fourth electrode, the fourth electrode being spaced apart from the third electrode and having a polarity different from that of the third electrode; and an upper dielectric layer formed on an upper side of the lower dielectric layer, the edge electrode portion, and the center electrode portion, in, In a plan view, the bipolar electrostatic chuck is divided into an edge electrode forming area, a center electrode forming area and a center area, the edge electrode forming area corresponds to a region from the edge to the edge electrode portion, the center electrode forming area is defined by the outer boundary of the center electrode portion, and the center area corresponds to a region excluding the edge electrode forming area and the center electrode forming area, wherein when the total area of ​​the bipolar electrostatic chuck is in the range of 2200mm*2500mm to 3100mm*3400mm, the edge electrode forming area has a width of 200mm, and the center electrode forming area has an area of ​​300mm*300mm.

5. The bipolar electrostatic chuck of any one of claims 1 or 4, wherein the upper dielectric layer comprises: a first upper dielectric layer formed on the edge electrode portion; a second upper dielectric layer connected to the lower dielectric layer in the central region; and a third upper dielectric layer formed on the central electrode portion, The first upper dielectric layer and the third upper dielectric layer have a higher dielectric constant than the second upper dielectric layer, or have a lower specific resistance than the second upper dielectric layer.

6. The bipolar electrostatic chuck of any one of claims 1 or 4, wherein the upper dielectric layer comprises: a fourth upper dielectric layer connected to the lower dielectric layer in the central region; and a sixth upper dielectric layer formed on the upper side of the edge electrode portion, the central electrode portion, and the fourth upper dielectric layer, The sixth upper dielectric layer has a higher dielectric constant than that of the fourth upper dielectric layer, or has a smaller specific resistance than that of the fourth upper dielectric layer.

7. The bipolar electrostatic chuck of any one of claims 1, 2 or 4, wherein the upper dielectric layer comprises: a first recessed portion provided as a boundary between the edge electrode forming region and the central region and having a recessed upper surface; and The second recessed portion extends across the central region and has a recessed upper surface.

8. The bipolar electrostatic chuck of any one of claims 1, 2 or 4, wherein the upper dielectric layer comprises: A first recessed portion, provided as a boundary between the edge electrode forming region and the central region, and having a recessed upper surface; a second recessed portion extending across the central region and having a recessed upper surface; and The third recessed portion is provided as a boundary between the central region and the central electrode forming region and has a recessed upper surface.

9. The bipolar electrostatic chuck of claim 5, wherein the second upper dielectric layer is formed of Al2O3, and The first upper dielectric layer and the third upper dielectric layer are formed with Al2O3 to which at least one particle selected from the group consisting of TiC, TiO2, Cr2O3, MnO2, COC, and CuO is added.

10. The bipolar electrostatic chuck of claim 9, wherein the first upper dielectric layer, the second upper dielectric layer, and the third upper dielectric layer have a surface roughness (Ra) of 2 to 3.5 µm.

Images