WO2009008598A2

WO2009008598A2 - Method of hydrating a ceramic spray-coating layer, method of manufacturing an electrostatic chuck that uses the hydrating method, and substrate structure and electrostatic chuck having the ceramic spray-coating layer formed using the hydrating method

Info

Publication number: WO2009008598A2
Application number: PCT/KR2008/003386
Authority: WO
Inventors: Kyung-Ic Jang; Kyung-Hwan Ye; Sam-Woong Kim; Hyun-Mi Yuk
Original assignee: Komico Ltd.
Priority date: 2007-07-10
Filing date: 2008-06-16
Publication date: 2009-01-15
Also published as: KR100863932B1; TW200903706A; WO2009008598A3

Abstract

In a method of hydrating a ceramic spray-coating layer of an electrostatic chuck, water penetrates into pores and/or cracks of the ceramic spray-coating layer, and the penetrated water then reacts with the ceramic spray-coating layer to form hydroxide in the pores and/or cracks. As a result, the electrical characteristics and hydrophobicity of the ceramic spray-coating layer may be improved.

Description

METHOD OF HYDRATING A CERAMIC SPRAY-COATING LAYER, METHOD OF MANUFACTURING AN ELECTROSTATIC CHUCK THAT USES THE HYDRATING METHOD, AND SUBSTRATE STRUCTURE AND ELECTROSTATIC CHUCK HAVING THE CERAMIC SPRAY- COATING LAYER FORMED USING THE HYDRATING

METHOD Technical Field

[1] The present invention relates to a method of hydrating a ceramic spray-coating layer, a method of manufacturing an electrostatic chuck that uses the hydrating method, and a substrate structure and an electrostatic chuck having the ceramic spray-coating layer formed using the hydrating method. More particularly, the present invention relates to a method of forming hydroxide in pores and/or microcracks of a ceramic spray-coating layer to hydrate the ceramic spray-coating layer, a method of manufacturing an electrostatic chuck that uses the hydrating method, and a substrate structure and an electrostatic chuck having the ceramic spray-coating layer formed using the hydrating method. Background Art

[2] A ceramic spray-coating layer may be used as a dielectric layer of an electrostatic chuck or a coating layer of a semiconductor device or liquid crystal display (LCD) device. The ceramic spray-coating layer may have a porosity of about 10% and may include pores and/or microcracks. Leakage current may occur due to the pores and/or the microcracks and electrical characteristics of the ceramic spray-coating layer may thus be deteriorated. A hydrating process, in which the ceramic spray-coating layer reacts with water to form hydroxide in the pores and/or the microcracks, may be performed to prevent the electrical characteristics of the ceramic spray-coating layer from deteriorating.

[3] For example, the ceramic spray-coating layer may be processed for a long time, e.g., for about 24 hours, using high-temperature water, e.g., using water having a temperature higher than about 6O⁰C, or high-temperature high-pressure water vapor. IHbwever, while hydrating the spray-coating layer, the water or the water vapor may penetrate a substrate on which the spray-coating layer is formed, thereby forming water spots on the substrate or damaging the substrate. Thus, an additional process, in which a blocking member is disposed on the substrate, may be required to prevent the water from penetrating the substrate. In this case, the substrate may be contaminated by an adhesive used to allow the blocking member to adhere to the substrate.

Disclosure of Invention

Technical Problem [4] Example embodiments of the present invention provide a method of hydrating a ceramic spray-coating layer capable of preventing damage to a substrate. [5] Further, example embodiments of the present invention provide a method of manufacturing an electrostatic chuck that uses the hydrating method as mentioned above. [6] Still further, example embodiments of the present invention provide a substrate structure having a ceramic spray-coating layer formed using the hydrating method as mentioned above. [7] Still further, example embodiments of the present invention provide an electrostatic chuck having a ceramic spray-coating layer formed using the hydrating method as mentioned above.

Technical Solution [8] In a method of hydrating a ceramic spray-coating layer according to an aspect of the present invention, water may penetrate the ceramic spray-coating layer, and the penetrated water may react with the ceramic spray-coating layer to form hydroxide in the ceramic spray-coating layer. [9] In some example embodiments of the present invention, the water may be supplied to the ceramic spray-coating layer at atmospheric pressure for about 1 to about 10 minutes to allow the water to penetrate the ceramic spray-coating layer and may have a temperature of about 10 to about 4O⁰C. [10] In some example embodiments of the present invention, the ceramic spray-coating layer may be heated to a temperature of about 60 to about 12O⁰C for about 1 to about

10 hours to form the hydroxide. [11] In some example embodiments of the present invention, the water on the ceramic spray-coating layer may be removed before forming the hydroxide. [12] In some example embodiments of the present invention, the water remaining in the ceramic spray-coating layer in which the hydroxide is formed may be removed. [13] In some example embodiments of the present invention, the ceramic spray-coating layer in which the hydroxide is formed may be heated to a temperature of about 60 to about 12O⁰C under a pressure of about 1O² to about 1O⁴ torr for about 1 to about 48 hours to remove the remaining water.

[14] In some example embodiments of the present invention, alcohol may be supplied onto the ceramic spray-coating layer in which the hydroxide is formed, and the ceramic spray-coating layer in which the hydroxide is formed may be heated to a temperature of about 60 to about 12O⁰C for about 1 to about 24 hours.

[15] In some example embodiments of the present invention, the steps of allowing the water to penetrate the ceramic spray-coating layer and reacting the penetrated water with the ceramic spray-coating layer to form the hydroxide may be repeatedly performed.

[16] In a method of manufacturing an electrostatic chuck according to another aspect of the present invention, a first ceramic spray-coating layer may be formed on a body. An electrode may be formed on a portion of an upper surface of the first ceramic spray- coating layer. A second ceramic spray-coating layer may be formed on the electrode and a remaining portion of the upper surface of the first ceramic spray-coating layer. Water may penetrate the second ceramic spray-coating layer, and the penetrated water may react with the second ceramic spray-coating layer to form hydroxide in the second ceramic spray-coating layer.

[17] A substrate structure, according to still another aspect of the present invention, may include a substrate and a ceramic spray-coating layer on the substrate. Ibres and/or cracks in the ceramic spray-coating layer may be filled with hydroxide.

[18] In some example embodiments of the present invention, the ceramic spray-coating layer may have a volume resistance of about 1.0e+14 to about 8.0e+14 Ω-cm when a voltage of about 5 V//M is applied.

[19] In some example embodiments of the present invention, the ceramic spray-coating layer may have a dielectric constant of about 11.39 to about 12.04 ε_r at a frequency of about 1 kHz to about 13.5 MHz.

[20] An electrostatic chuck, according to still another aspect of the present invention, may include a body, a first ceramic spray-coating layer on the body, an electrode on a portion of an upper surface of the first ceramic spray-coating layer, and a second ceramic spray-coating layer on the electrode and a remaining portion of the upper surface of the first ceramic spray-coating layer. The second ceramic spray-coating layer may have pores and/or cracks filled with hydroxide.

Advantageous Effects

[21] In accordance with the example embodiments of the present invention, hydroxide may be formed in pores and/or cracks of a ceramic spray-coating layer by allowing water to penetrate into the pores and/or the cracks and then heating the ceramic spray- coating layer. Thus, the water may be prevented from penetrating a substrate on which the ceramic spray-coating layer is formed. As a result, water spots may thus be prevented from forming on the substrate, and further damage to the substrate may be reduced.

[22] Further, the electrical characteristics of the ceramic spray-coating layer may be improved by a hydrating process. Particularly, the volume resistance of the ceramic spray-coating may be increased, leakage current through the ceramic spray-coating layer may be reduced, and the dielectric constant of the ceramic spray-coating layer may be increased. Moreover, the hydrophobicity of the ceramic spray-coating layer may be improved. Brief Description of the Drawings

[23] Example embodiments of the present invention will become readily apparent along with the following detailed description when considered in conjunction with the accompanying drawings, wherein:

[24] FIG. 1 is a flowchart illustrating a method of hydrating a ceramic spray-coating layer according to an example embodiment of the present invention;

[25] FIG. 2 is a flowchart illustrating a method of manufacturing an electrostatic chuck according to another example embodiment of the present invention;

[26] FIG. 3 is a picture showing the hydrophobicity of a ceramic spray-coating layer before a hydrating process;

[27] FIG. 4 is a picture showing the hydrophobicity of a ceramic spray-coating layer after a hydrating process;

[28] FIG. 5 is a cross-sectional view illustrating a substrate structure having a ceramic spray-coating layer formed using the method shown in FIG. 1 ; and

[29] FIG. 6 is a cross-sectional view illustrating an electrostatic chuck formed using the method shown in FIG. 2. Best Mode for Carrying Out the Invention

[30] Embodiments of the invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as 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 invention to those skilled in the art. Like reference numerals refer to like elements throughout.

[31] It will be understood that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

[32] It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first thin film could be termed a second thin film, and, similarly, a second thin film could be termed a first thin film without departing from the teachings of the disclosure.

[33] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising" or "includes" and/or "including" when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.

[34] Furthermore, relative terms, such as "lower" or "bottom" and "upper" or "top" may be used herein to describe one element's relationship to other elements as illustrated in the Figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. For example, if the device in one of the figures is turned over, elements described as being on the "lower" side of other elements would then be oriented on "upper" sides of the other elements. The exemplary term "lower," can therefore, encompass both an orientation of "lower" and "upper" depending on the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as "below" or "beneath" other elements would then be oriented "above" the other elements. The exemplary terms "below" or "beneath" can, therefore, encompass both an orientation of above and below.

[35] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[36] Example embodiments of the present invention are described herein with reference to cross-section illustrations that are schematic illustrations of idealized embodiments of the present invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the present invention should not be construed as limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region illustrated or described as flat may, typically, have rough and/or nonlinear features. Moreover, sharp angles that are illustrated may be rounded. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the present invention.

[37]

[38] Method of hvdrating ceramic spray-coating layer

[39] FIG. 1 is a flowchart illustrating a method of hydrating a ceramic spray-coating layer according to an example embodiment of the present invention.

[40] Referring to FIG. 1, a substrate on which a coating layer is formed may be prepared.

The substrate may include a metal, for example, aluminum. An anodized layer may be disposed on a surface of the substrate. The coating layer may be a ceramic spray- coating layer, and examples of a ceramic material that may be used for the ceramic spray-coating layer may include Al ₂O₃, Y₂O₃, ZrO₂, AlC, TiN, AlN, TiC, MgO, CaO, CeO₂, TiO₂, B_xC_y, BN, SO₂, SC, YAG, Mullite, AlF ₃, and the like. These materials may be used alone or in a combination thereof.

[41] For example, the substrate may have a first region and a second region adjacent to the first region. The coating layer may be formed on the first region of the substrate.

[42] Water may be sprayed on the coating layer or the coating layer may be immersed in water to allow the water to penetrate into pores and/or microcracks of the coating layer in step SI lO.

[43] In accordance with an example embodiment of the present invention, water may be sprayed on the coating layer. The water may be deionized water or may have a pH of about 6 to about 8. For example, water having a temperature of about 10 to about 4O⁰C may be sprayed on the coating layer at atmospheric pressure for about 1 to about 10 minutes. Particularly, water having a temperature of about 20 to about 3O⁰C may be sprayed on the coating layer for about 3 to about 7 minutes.

[44] In accordance with another example embodiment of the present invention, the substrate on which the coating layer is formed may be immersed in water. The water may be deionized water or may have a pH of about 6 to about 8. For example, the substrate on which the coating layer is formed may be immersed in water having a temperature of about 10 to about 4O⁰C for about 1 to about 10 minutes. Particularly, the substrate on which the coating layer is formed may be immersed in water having a temperature of about 20 to about 3O⁰C for about 3 to about 7 minutes.

[45] When the water is not deionized water, ions contained in the water may influence the coating layer, and when the water has a pH lower than about 6 or higher than about 8, the coating layer may be damaged by the water. Further, when the water has a temperature lower than about 1O⁰C, it may be difficult for the water to penetrate the coating layer, and when the water has a temperature higher than about 4O⁰C, the water may excessively penetrate the coating layer or may penetrate the substrate. Still further, when the time required to spray the water or to immerse the substrate in the water is less than about 1 minute, it may be difficult for the water to sufficiently penetrate the coating layer, and when the time required to spray the water or to immerse the substrate in the water is more than about 10 minutes, the water may excessively penetrate the coating layer or may penetrate the substrate.

[46] In accordance with some example embodiments of the present invention, the water may be prevented from penetrating the substrate by spraying the water on the coating layer or immersing the coating layer in the water at atmospheric pressure for about 1 to about 10 minutes.

[47] Then, the water may be removed from surfaces of the coating layer and the substrate in step S 120. For example, air may be sprayed on the coating layer and the substrate, or surfaces of the coating layer and the substrate may be wiped with a cloth capable of absorbing the water. Alternatively, air may be sprayed on the coating layer and the substrate, and the surfaces of the coating layer and the substrate may then be wiped with a cloth capable of absorbing the water.

[48] In accordance with another example embodiment of the present invention, air may be sprayed on the substrate, or surfaces of the substrate may be wiped with a cloth capable of absorbing the water. Alternatively, air may be sprayed on the substrate, and the surfaces of the substrate may then be wiped with a cloth capable of absorbing the water. That is, only the water on the substrate may be selectively removed.

[49] As described above, the water on the substrate may be removed to thereby prevent the water from penetrating the substrate and thus forming water spots on the substrate or damaging the substrate.

[50] The coating layer, into which the water penetrates, may be heated to form hydroxide in the pores and/or the microcracks in step S 130. For example, the coating layer, into which the water penetrates, may be heated to a temperature of about 60 to about 12O⁰C for about 1 to about 10 hours. Particularly, the coating layer, into which the water penetrates, may be heated to a temperature of about 90 to about 11O⁰C for about 4 to about 6 hours. The ceramic material of the coating layer may be reacted with the water in the pores and/or the microcracks, thereby forming the hydroxide in the pores and/or microcracks.

[51] When the heating temperature is lower than about 6O⁰C, the ceramic material may not be reacted with the water in the pores and/or the microcracks, and when the heating temperature is higher than about 12O⁰C, cracks may occur in the coating layer, or the anodized layer may be peeled off the substrate. Further, the heating time is less than about 1 hour, the reaction between the coating layer and the water may not be sufficient, and when the heating time is more than about 10 hours, the reaction between the coating layer and the water may not occur any longer because the water may already be exhausted.

[52] For example, when the coating layer includes aluminum oxide (Al ₂O₃), aluminum hydroxide (Al(OH)₃) may be formed by a reaction between the aluminum oxide and the water. Further, when the coating layer includes yttrium oxide (Y₂O₃), yttrium hydroxide (Y(OH)₃) may be formed by a reaction between the yttrium oxide and the water.

[53] The pores and/or the microcracks may be filled with the hydroxide, thereby improving the electrical characteristics of the coating layer. In particular, the volume resistance of the coating layer may be increased, thereby reducing leakage current through the coating layer. Further, the dielectric constant of the coating layer may be increased.

[54] Further, the hydrophobicity of the coating layer may be improved because the pores and/or the microcracks of the coating layer are filled with the hydroxide. Thus, water may be prevented from penetrating the hydrated coating layer.

[55] Even though the steps of allowing the water to penetrate into the pores and/or the microcracks (step Sl 10), removing the water from the surfaces of the coating layer and the substrate (step S 120), and forming the hydroxide in the pores and/or microcracks (step S 130) are performed, the pores and/or microcracks may not be sufficiently filled with the hydroxide. In this case, the steps of allowing the water to penetrate into the pores and/or the microcracks (step Sl 10), removing the water from the surfaces of the coating layer and the substrate (step S 120), and forming the hydroxide in the pores and/or microcracks (step S 130) may be repeatedly performed to sufficiently form the hydroxide in the pores and/or the microcracks. The steps may be repeated about 2 to 15 times, and the number of times may be determined in accordance with the ceramic material composing the coating layer. When the number of times is more than 15, the pores and/or the microcracks may be sufficiently filled with the hydroxide, and the hydroxide may not be formed any further.

[56] Even though the hydroxide is formed in the pores and/or the microcracks, some water may remain in the pores and/or the microcracks without reacting with the ceramic material. The remaining water may deteriorate the electrical characteristics of the coating layer.

[57] In accordance with an example embodiment of the present invention, the coating layer and the substrate may be additionally heated to remove the remaining water. For example, the hydrated coating layer may be heated to a temperature of about 60 to about 12O⁰C under a pressure of about 10^~2 to about 10^~4 torr for about 1 to about 48 hours. Particularly, the hydrated coating layer may be heated to a temperature of about 90 to about 11O⁰C under a pressure of about 10^~4 torr for about 12 to about 24 hours. As a result, the remaining water in the pores and/or microcracks may be sufficiently removed.

[58] When the pressure is higher than about 10^~2 torr, the remaining water may not be sufficiently removed, and when the pressure is lower than about 10^'4 torr, the time required to prepare the vacuum environment may be increased. Further, when the heating temperature is lower than about 6O⁰C, the remaining water may not be sufficiently removed, and when the heating temperature is higher than about 12O⁰C, cracks may occur in the hydrated coating layer, or the anodized layer may be peeled off the substrate. Still further, when the heating time is less than about 1 hour, the remaining water may not be sufficiently removed, and when the heating time is more than about 48 hours, the process time may be increased.

[59] In accordance with another example embodiment of the present invention, alcohol, such as ethyl alcohol, isopropyl alcohol, or the like, may be applied to the hydrated coating layer. The alcohol may be sprayed on the hydrated coating layer. Alternatively, the hydrated coating layer may be immersed in the alcohol.

[60] The hydrated coating layer may then be heated to a temperature of about 60 to about

12O⁰C for about 1 to about 24 hours. Particularly, the hydrated coating layer may be heated to a temperature of about 90 to about 11O⁰C for about 8 to about 16 hours.

[61] When the heating temperature is lower than about 6O⁰C, the remaining water may not be sufficiently removed, and when the heating temperature is higher than about 12O⁰C, cracks may occur in the hydrated coating layer, or the anodized layer may be peeled off the substrate. Further, when the heating time is less than about 1 hour, the remaining water may not be sufficiently removed, and when the heating time is more than about 24 hours, the process time may be increased.

[62] As a result, the time required to remove the remaining water in the pores and/or the microcracks may be shortened by applying the alcohol to the hydrated coating layer.

[63] In accordance with some example embodiments of the present invention, the water may not penetrate the substrate, thereby preventing the occurrence of water spots on the substrate and damage to the substrate. Further, there is no need for an additional process of disposing a blocking member on the substrate to prevent the water from penetrating the substrate, and the substrate may be prevented from being contaminated by an adhesive used to allow the blocking member to adhere to the substrate. Still further, the electrical characteristics and hydrophobicity of the coating layer may be improved by the hydrating process, and the lifetime of the coating layer may be increased as well.

[64]

[65] Method of manufacturing an electrostatic chuck

[66] A method of manufacturing an electrostatic chuck now will be described hereinafter, which may employ the method of hydrating the ceramic spray-coating layer described with reference to FIG. 1.

[67] FIG. 2 is a flowchart illustrating a method of manufacturing an electrostatic chuck according to another example embodiment of the present invention.

[68] Referring to FIG. 2, a first ceramic spray-coating layer may be formed on an upper surface of a substrate in step S210.

[69] For example, the substrate may include metal. An example of the metal may include aluminum. Alternatively, a metal-coating layer may be formed on the substrate.

[70] A ceramic powder may be melted by a plasma thermal spray-coating method, and the melted ceramic powder may be injected onto the upper surface of the substrate. Particularly, a source gas, such as argon (Ar), nitrogen (N₂), hydrogen (H₂), helium (He), and the like, may be introduced through a gas inlet of a plasma gun and may pass through a gap between a cathode and an anode to which a high voltage and a high current, for example, a voltage of about 30 to about 100 kV and a current of about 400 to about 1,000 A, are applied, thereby forming a high-temperature plasma flame having a temperature of about 5,000 to about 15,000⁰C. A cooling line may be disposed within the anode to cool the anode, which may be heated by the high- temperature plasma flame. The ceramic powder may be introduced into the high- temperature plasma flame through a powder inlet. The ceramic powder may be fully or partially melted by the high-temperature plasma flame and may be injected toward the substrate at a high speed of about 200 to about 700 m/s to coat the upper surface of the substrate.

[71] Examples of a material that may be used for the ceramic powder may include Al ₂O₃,

Y₂O₃, ZrO₂, AlC, TiN, AlN, TiC, MgO, CaO, CeO₂, TiO₂, B_xC_y, BN, SO₂, SC, YAG, Mullite, AlF₃, and the like. The materials may be used alone or in a combination thereof.

[72] Alternatively, before forming the first ceramic spray-coating layer, an adhesive layer may be formed on the upper surface of the substrate. The adhesive layer may include metal may be formed by a vacuum deposition process or a plasma spray-coating process. An example of the metal that may be used for the adhesive layer may include a nickel- aluminum alloy. The adhesive layer may have a coefficient of thermal expansion between those of the substrate and the first ceramic spray-coating layer.

[73] An electrode may be formed on a portion of an upper surface of the first ceramic spray-coating layer in step S220. For example, a conductive material may be deposited on the portion of the first ceramic spray-coating layer.

[74] In particular, the conductive layer may be deposited by a spray-coating process, a silk screen process, a chemical vapor deposition (CVD) process, a physical vapor deposition process, and the like. An example of the conductive material may include tungsten.

[75] Alternatively, a conductive plate that may be used as the electrode may be attached to the portion of the upper surface of the first ceramic spray-coating layer.

[76] A second ceramic spray-coating layer may be formed on the electrode and a remaining portion of the upper surface of the first ceramic spray-coating layer in step S230.

[77] Step S230 of forming the second ceramic spray-coating layer is similar to step S210 of forming the first ceramic spray-coating layer. [78] Meanwhile, an electrostatic chuck may include the substrate, the first ceramic spray- coating layer, the electrode and the second ceramic spray-coating layer.

[79] The second ceramic spray-coating layer may be hydrated in step S240.

[80] For example, water may be sprayed onto the electrostatic chuck or the second ceramic spray-coating layer to allow the water to penetrate into pores and/or mi- crocracks of the second ceramic spray-coating layer. Alternatively, the electrostatic chuck may be immersed in water to allow the water to penetrate into the pores and/or the microcracks of the second ceramic spray-coating layer.

[81] The water of surfaces of the electrostatic chuck or surfaces of the substrate may be removed. The second ceramic spray-coating layer may be heated to react with the penetrated water and to thereby form hydroxide in the pores and/or the microcracks of the second ceramic spray-coating layer. The water remaining in the second ceramic spray-coating layer may be removed.

[82] Further detailed descriptions for step S240 of hydrating the second ceramic spray- coating layer may be omitted because step S240 is similar to the method of steps Sl 10 to S 140 of hydrating the spray-coating layer already described with reference to FIG. 1.

[83] In accordance with another example embodiment of the present invention, the first ceramic spray-coating layer may be hydrated as well as the second ceramic spray- coating layer. For example, the first and second ceramic spray-coating layers may be simultaneously hydrated. Alternatively, the first and second ceramic spray-coating layers may be individually hydrated. In detail, the first ceramic spray-coating layer may be hydrated after forming the first ceramic spray-coating layer, and the second ceramic spray-coating layer may be hydrated after forming the second ceramic spray- coating layer. A method of hydrating the first ceramic spray-coating layer is similar to the method of steps S 110 to S 140 of hydrating the spray-coating layer already described with reference to FIG. 1.

[84] According to the method of manufacturing the electrostatic chuck, the electrical characteristics and the hydrophobicity of the second ceramic spray-coating layer may be improved by hydrating the second ceramic spray-coating layer. As a result, the lifetime of the electrostatic chuck may be increased.

[85]

[86] Example 1

[87] [Table 1]

[88]

[89] Table 1 represents the volume resistance of a ceramic spray-coating layer including yttrium oxide.

[90] Referring to Table 1, when a voltage of about 5 V//M was applied, volume resistance of the ceramic spray-coating layer was about 6.0e+10 Ω-cm before the hydrating process. The volume resistance of the ceramic spray-coating layer was increased to about 8.0e+14 Ω-cm after the hydrating process. Further, the volume resistance of the ceramic spray-coating layer was about 3.0e+14, about 2.0e+14 and about 1.0e+14 Ω- cm, respectively, when the ceramic spray-coating layer was exposed to the atmosphere for about 24 hours, about 96 hours and about 168 hours after the hydrating process. Thus, it is understood that the volume resistance of the ceramic spray-coating layer may be increased by the hydrating process.

[91] [92] Example 2 [93] [Table 2] [94]

[95] Table 2 represents the leakage current of a ceramic spray-coating layer including yttrium oxide.

[96] Referring to Table 2, when voltages of 1,000 V, 2,000 V and 3,000 V were applied to the ceramic spray-coating layer before the hydrating process, the leakage current of the ceramic spray-coating layer was increased to 0.8 μk, 16 μk and 168 μλ, respectively. Further, when a voltage of 4,000 V was applied to the ceramic spray-coating layer, the ceramic spray-coating layer was electrically failed. [97] When voltages of 1,000 V, 2,000 V, 3,000 V and 4,000 V were applied to the ceramic spray-coating layer directly after the hydrating process, the leakage current through the ceramic spray-coating layer was not measured. Even though the ceramic spray-coating layer was exposed to the atmosphere for about 24 hours, about 96 hours and about 168 hours after the hydrating process, the leakage current through the ceramic spray-coating layer was not measured. Thus, it is understood that the leakage current through the ceramic spray-coating layer may be prevented by the hydrating process.

[98] [99] EXAMPLE 3 [100] [Table 3] [101]

[102] Table 3 represents the dielectric constant of a ceramic spray-coating layer including yttrium oxide. [103] Referring to Table 3, the dielectric constant of the ceramic spray-coating layer was increased after performing the hydrating process. Thus, it is understood that the dielectric constant of the ceramic spray-coating layer may be improved by the hydrating process.

[104] FIG. 3 is a picture showing the hydrophobicity of the ceramic spray-coating layer before the hydrating processing, and FIG. 4 is a picture showing the hydrophobicity of the ceramic spray-coating layer after the hydrating process.

[105] Referring to FIG. 3, before performing the hydrating process, a bead of water spreads on a surface of the ceramic spray-coating layer. It is understood that the hydrophobicity of the ceramic spray-coating layer is poor before the hydrating process. Referring to FIG. 4, after performing the hydrating process, a bead of water is not spread on the hydrated ceramic spray-coating layer. It is understood that the hy^¬ drophobicity of the ceramic spray-coating layer is improved by the hydrating process.

[106] [107] Substrate structure

[108] FIG. 5 is a cross-sectional view illustrating a substrate structure having a ceramic spray-coating layer formed by the method of hydrating the ceramic spray-coating layer described with reference to FIG. 1

[109] Referring to FIG. 5, a substrate structure 100 may include a substrate 110 and a ceramic spray-coating layer 120.

[110] The substrate 110 may serve as an object on which the ceramic spray-coating layer may be formed and may have various shapes as well as a plate shape.

[I l l] The ceramic spray-coating layer 120 may be disposed on the substrate 110. The ceramic spray-coating layer may have pores and/or cracks filled with hydroxide therein. The hydroxide may be formed by the hydrating process already described with reference to FIG. 1.

[112] The volume resistance of the hydrated ceramic spray-coating layer 120 may be increased and the leakage current through the hydrated ceramic spray-coating layer 120 may be reduced in comparison with those of a ceramic spray-coating layer without performing the hydrating process because the pores and/or cracks are filled with the hydroxide.

[113] In detail, when a voltage of about 5 V//M is applied, the ceramic spray-coating layer 120 may have a volume resistance of about 1.0e+14 to about 8.0e+14 Ω-cm. Further, even though a voltage of about 1,000 to 4,000 V is applied, the leakage current through the ceramic spray-coating layer 120 does not occur. Still further, the ceramic spray- coating layer 120 may have a dielectric constant of about 11.39 to about 12.04 ε_r at a frequency of about 1 kHz to about 13.5 MHz.

[114]

[115] Electrostatic Chuck

[116] FIG. 6 is a cross-sectional view illustrating an electrostatic chuck formed using the method shown in FIG. 2.

[117] Referred to FIG. 6, an electrostatic chuck 200 may include a body 210, a first ceramic spray-coating layer 220, an electrode 230 and a second ceramic spray-coating layer 240.

[118] The body 210 may have a plate shape. A size of the body 210 may be equal to or greater than that of a substrate that may be used to manufacture semiconductor devices or flat panel display devices. The body 210 may include metal. An example of the metal may include aluminum. Alternatively, a metal layer may be formed on a surface of the body 210. [119] The first ceramic spray-coating layer 220 may be disposed on the body 210.

Examples of a ceramic material that may be used for the first ceramic spray-coating layer 220 may include Al₂O₃, Y₂O₃, ZrO₂, AlC, TiN, AlN, TiC, MgO, CaO, CeO₂, TiO 2, B_xC_y, BN, SO₂, SC, YAG, Mullite, AlF ₃, and the like. These ceramic materials may be used alone or in a combination thereof. The first ceramic spray-coating layer 220 may be used to electrically insulate the electrode 230 from the body 210.

[120] Meanwhile, an adhesive layer (not shown) may be disposed between the body 210 and the first ceramic spray-coating layer 220. The adhesive layer may be used to allow the first ceramic spray-coating layer 220 adhere to the body 210. Further, the adhesive layer may have a coefficient of thermal expansion between those of the body 210 and the first ceramic spray-coating layer 220 and may absorb shock due to thermal expansion between the body 210 and the first ceramic spray-coating layer 220. The adhesive layer may include metal alloy. An example of the metal alloy may include nickel-aluminum alloy.

[121] The electrode 230 may be disposed on a portion of an upper surface of the first ceramic spray-coating layer 220. Electric power may be applied to the electrode 230, and an electrostatic force may thus be generated to hold the substrate. The electrode 230 may include metal. Examples of the metal that may be used for the electrode 230 may include tungsten, molybdenum or alloy thereof.

[122] In accordance with the present example embodiment, one electrode 230 may be disposed on the first ceramic spray-coating layer 220.

[123] In accordance with another example embodiment of the present invention, the electrode 230 may include a first electrode and a second electrode. The first and second electrodes may be disposed to cross each other on the first ceramic spray- coating layer 220 and may not be electrically connected with each other. Different types of power may be applied to each of the first and second electrodes. For example, a positive potential may be applied to the first electrode and a negative potential may be applied to the second electrode.

[124] The second ceramic spray-coating layer 240 may be disposed on the electrode 230 and a remaining portion of the upper surface of the first ceramic spray-coating layer 220. The second ceramic spray-coating layer 240 may be used to support the substrate. Examples of a ceramic material that may be used for the second ceramic spray-coating layer 240 may include Al₂O₃, Y₂O₃, ZrO₂, AlC, TiN, AlN, TiC, MgO, CaO, CeO₂, TiO 2, B_xC_y, BN, SO₂, SC, YAG, Mullite, AlF ₃, and the like. These ceramic materials may be used alone or in a combination thereof. [125] lores and/or cracks within the second ceramic spray-coating layer 240 may be filled with hydroxide, which may be formed by the hydrating method described with reference to FIG. 1.

[126] The volume resistance of the second ceramic spray-coating layer 240 may be increased and the leakage current through the second ceramic spray-coating layer 240 may be reduced in comparison with those of a ceramic spray-coating layer without performing the hydrating process because the pores and/or cracks are filled with the hydroxide.

[127] In detail, when a voltage of about 5 V//M is applied, the second ceramic spray- coating layer 240 may have a volume resistance of about 1.0e+14 to about 8.0e+14 Ω- cm. Further, even though a voltage of about 1,000 to 4,000 V is applied, the leakage current through the second ceramic spray-coating layer 240 does not occur. Still further, the second ceramic spray-coating layer 240 may have a dielectric constant of about 11.39 to about 12.04 ε_r at a frequency of about 1 kHz to about 13.5 MHz.

[128] In accordance with another example embodiment of the present invention, a plurality of protrusions may be disposed on an upper surface of the second ceramic spray- coating layer 240 to support the substrate. A cooling gas may be supplied between the substrate and the second ceramic spray-coating layer 240 to cool the substrate.

[129] In accordance with the present example embodiment, the first and second ceramic spray-coating layers 220 and 240 may be formed of the same material. However, in accordance with another example embodiment of the present invention, the first and second ceramic spray-coating layers 220 and 240 may be formed of ceramic materials different from each other, respectively.

[130] In accordance with another example embodiment of the present invention, pores and/ or cracks within the first ceramic spray-coating layer 220 may be filled with hydroxide, which may be formed by the hydrating process described with reference to FIG. 1, as well as the second ceramic spray-coating layer 240.

[131] As described above, the electrical characteristics of the second ceramic spray-coating layer 240 may be improved by the hydrating process, thereby improving the performance of the electrostatic chuck 200. Industrial Applicability

[132] In a method of hydrating a ceramic spray-coating layer according to some example embodiments of the present invention, hydroxide may be formed in pores and/or cracks of a ceramic spray-coating layer by allowing water to penetrate into the pores and/or the cracks and then heating the ceramic spray-coating layer. The electrical char- acteristics of the ceramic spray-coating layer may be improved by a hydrating process. Particularly, the volume resistance of the ceramic spray-coating may be increased, leakage current through the ceramic spray-coating layer may be reduced, and the dielectric constant of the ceramic spray-coating layer may be increased. Further, the hy- drophobicity of the ceramic spray-coating layer may be improved.

[133] Moreover, in accordance with seme example embodiments of the present invention, there is no need to process a substrate, on which the ceramic spray-coating layer is formed, for a long time using high-temperature water or high-temperature high- pressure water vapor, thereby preventing water from penetrating the substrate. Thus, water spots may be prevented from forming on the substrate, and further damage to the substrate may be reduced.

[134] Although the example embodiments of the present invention have been described, it is understood that the present invention should not be limited to these example embodiments but various changes and modifications can be made by those skilled in the art within the spirit and scope of the present invention as hereinafter claimed.

Claims

[1] A method of hydrating a ceramic spray-coating layer comprising: allowing water to penetrate the ceramic spray-coating layer; and reacting the penetrated water with the ceramic spray-coating layer to form hydroxide.

[2] The method of claim 1, wherein the water is supplied to the ceramic spray- coating layer at atmospheric pressure for about 1 to about 10 minutes to allow the water to penetrate the ceramic spray-coating layer and has a temperature of about 10 to about 4O⁰C.

[3] The method of claim 1, wherein the ceramic spray-coating layer is heated to a temperature of about 60 to about 12O⁰C for about 1 to about 10 hours to form the hydroxide.

[4] The method of claim 1, wherein the water on the ceramic spray-coating layer is removed before forming the hydroxide.

[5] The method of claim 1, further comprising removing the water remaining in the ceramic spray-coating layer in which the hydroxide is formed.

[6] The method of claim 5, wherein the ceramic spray-coating layer in which the hydroxide is formed is heated to a temperature of about 60 to about 12O⁰C under a pressure of about 10^~2 to about 10^~4 torr for about 1 to about 48 hours to remove the remaining water.

[7] The method of claim 5, wherein removing the remaining water comprises: supplying alcohol onto the ceramic spray-coating layer in which the hydroxide is formed; and heating the ceramic spray-coating layer in which the hydroxide is formed to a temperature of about 60 to about 12O⁰C for about 1 to about 24 hours.

[8] The method of claim 1, further comprising repeatedly performing allowing the water to penetrate the ceramic spray-coating layer and reacting the penetrated water with the ceramic spray-coating layer to form hydroxide.

[9] A method of manufacturing an electrostatic chuck comprising: forming a first ceramic spray-coating layer on a body; forming an electrode on a portion of an upper surface of the first ceramic spray- coating layer; forming a second ceramic spray-coating layer on the electrode and a remaining portion of the upper surface of the first ceramic spray-coating layer; allowing water to penetrate the second ceramic spray-coating layer; and reacting the penetrated water with the second ceramic spray-coating layer to form hydroxide. [10] A substrate structure comprising: a substrate; and a ceramic spray-coating layer on the substrate, the ceramic spray-coating layer having pores and/or cracks filled with hydroxide. [11] The substrate structure of claim 10, wherein the ceramic spray-coating layer has a volume resistance of about 1.0e+14 to about 8.0e+14 Ω-cm when a voltage of about 5 V//M is applied. [12] The substrate structure of claim 10, wherein the ceramic spray-coating layer has a dielectric constant of about 11.39 to about 12.04 ε_r at a frequency of about 1 kHz to about 13.5 MHz. [13] An electrostatic chuck comprising: a body; a first ceramic spray-coating layer on the body; an electrode on a portion of an upper surface of the first ceramic spray-coating layer; and a second ceramic spray-coating layer on the electrode and a remaining portion of the upper surface of the first ceramic spray-coating layer, the second ceramic spray-coating layer having pores and/or cracks filled with hydroxide.