Electrostatic chuck film

Abstract

The present invention relates to an electrostatic chuck film, and more particularly, to an electrostatic chuck film comprising an adhesive layer formed on a conductive layer, and having electrical properties within a prescribed range and a thickness of each layer. The electrostatic chuck film according to the present invention comprises: a substrate layer; the conductive layer is formed on the base material layer; and an adhesive layer formed on the conductive layer.

Description

Technical Field

[0001] This invention relates to an electrostatic chuck film, and more particularly, to an electrostatic chuck film comprising an adhesive layer formed on a conductive layer, and having electrical properties and thicknesses of each layer within a specified range, such that one side can be picked up by an electrostatic chuck while the other side can be bonded. Background Technology

[0002] Typically, an adhesive protective film is applied during the product manufacturing process to protect the product's surface. This adhesive protective film is particularly used in display devices such as mobile phones, computer monitors, TVs, and various billboards, including display panels such as LCD panels and plasma display panels (PDPs), as well as in semiconductor packaging processes.

[0003] Previously, most processes utilized pressure to pick up films or products, but this cannot be done in a vacuum. Specifically, semiconductor packaging processes occur in a vacuum, where adhesive forces were previously used to pick up films or products, but this resulted in difficulty in peeling them off. Therefore, specialized structures and characteristics such as electrostatic chucks are required.

[0004] Korean Patent No. 2208071 discloses a multilayer structure for electrostatic coupling of a substrate, but it has the disadvantage of requiring an external power source and its contact portion to charge the metal electrodes.

[0005] Furthermore, in the case of products, additional structural elements are required for pickup via the electrostatic chuck, but these elements may be unnecessary or detract from the product's functionality. Therefore, the industry has a strong need for pickup bodies with new structures and characteristics that can solve this problem.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent document 1: KR 10-2208071 (Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV) 2021.01.21. Summary of the Invention

[0009] Technical issues

[0010] The present invention is proposed to solve the problems described above, and its object is to provide an electrostatic chuck film comprising an adhesive layer formed on a conductive layer having electrical properties within a specified range, such that one side can be picked up by an electrostatic chuck while the other side can be adhered.

[0011] Furthermore, in addition to the aforementioned objectives, the present invention also aims to achieve other objectives that can be readily identified by those skilled in the art from these objectives and the overall description of this specification.

[0012] Problem Solving Methods

[0013] For the purposes described above, the electrostatic chuck film of the present invention is characterized by comprising: a substrate layer; a conductive layer formed on the substrate layer; and an adhesive layer formed on the conductive layer.

[0014] Furthermore, the substrate layer may be selected from the group consisting of polyethylene terephthalate, polyethylene, polyimide, acrylic resin, cyclic olefin polymers, mixtures thereof, and copolymers thereof.

[0015] Furthermore, the electrostatic chuck film of the present invention may also include a release film formed on the adhesive layer.

[0016] Furthermore, when a voltage of 1kV is applied to the electrostatic chuck film, the surface resistance can be 1×10⁻⁶. 11 Ω / sq up to 1×10 13 Ω / sq.

[0017] Furthermore, when a voltage of 1 kV is applied to the laminate of the substrate layer and the conductive layer, the surface resistance can be 1 × 10⁻⁶. 3 Ω / sq up to 1×10 7 Ω / sq.

[0018] Furthermore, when a voltage of 1 kV is applied to the adhesive layer, the surface resistance can be greater than 1 × 10⁻⁶. 13 Ω / sq.

[0019] Furthermore, under conditions of 25°C and 10GHz, the dielectric loss of the electrostatic chuck film can be from 0.02 to 0.1.

[0020] Furthermore, under conditions of 25°C and 10GHz, the dielectric loss of the laminate of the substrate layer and the conductive layer can be from 0.1 to 0.23.

[0021] Furthermore, under conditions of 25°C and 10GHz, the dielectric loss of the laminate of the substrate layer and the adhesive layer can be from 0.007 to 0.009.

[0022] Furthermore, under conditions of 25°C and 10GHz, the dielectric constant of the electrostatic chuck film can be between 2.8 and 3.3.

[0023] Furthermore, under conditions of 25°C and 10GHz, the dielectric constant of the laminate of the substrate layer and the conductive layer can be 3.0 to 3.5.

[0024] Furthermore, under conditions of 25°C and 10GHz, the dielectric constant of the laminate of the substrate layer and the adhesive layer can be 2.9 to 3.2.

[0025] Furthermore, the conductive layer can be selected from the group consisting of poly(3,4-ethylenedioxythiophene) (PEDOT), poly(3,4-ethylenedioxythiophene)-polystyrenesulfonate (PEDOT-PSS), carbon nanotubes (CNT), graphene, indium tin oxide (ITO), silver nanowires, and combinations thereof.

[0026] Moreover, a cross-linking reaction can occur within the conductive layer.

[0027] Furthermore, the conductive layer can be formed by crosslinking a mixture of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) and water-dispersible polyurethane with a aziridine compound.

[0028] Furthermore, the aziridine compound may be selected from the group consisting of trimethylolpropane tris(2-methyl-1-aziridine)propionate, trimethylolpropane tris[3-(aziridin-1-yl)propionate], pentaerythritol tris[3-(1-aziridinyl)propionate], pentaerythritol tris(2-methyl-1-aziridine propionate) and mixtures thereof.

[0029] Furthermore, the weight ratio of the polyurethane to poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) in the conductive layer can be 1:9, 1.5:8.5, or 3:7.

[0030] Furthermore, the weight ratio of the mixture of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) and water-dispersible polyurethane in the conductive layer to the aziridine compound can be 100:8 to 63, 100:10 to 63, or 100:12 to 63.

[0031] Furthermore, the mixture of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) and water-dispersible polyurethane in the conductive layer can be a solution dissolved in a solvent selected from the group consisting of water, ethanol, methanol, isopropanol and mixtures thereof.

[0032] Furthermore, the solution may also contain a stabilizer selected from the group consisting of ethylene glycol, sorbitol, and mixtures thereof.

[0033] Furthermore, the concentration of the mixture of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) and polyurethane dissolved in a solvent selected from the group consisting of water, ethanol, methanol, isopropanol and mixtures thereof can be from 0.8% to 1.2% by weight or from 0.8% to 0.9% by weight.

[0034] Furthermore, the thickness of the conductive layer can be from 0.03 μm to 3 μm.

[0035] Furthermore, the adhesive layer may be selected from the group consisting of silicone, acrylic resin, urethane resin, rubber, and combinations thereof.

[0036] Furthermore, a curing reaction can occur within the adhesive layer.

[0037] Furthermore, the adhesive layer can be formed by reacting a compound selected from the group consisting of organopolysiloxane, chlorosilane, alkylalkoxysilane, sulfursilane, aminosilane, epoxysilane, and mixtures thereof with vinyl groups at both ends with a silane or silane derivative.

[0038] Furthermore, the reaction of the compounds selected from the group consisting of organopolysiloxane, chlorosilane, alkylalkoxysilane, sulfursilane, aminosilane, epoxysilane and mixtures thereof with silane or silane derivatives can be carried out using platinum as a catalyst.

[0039] Furthermore, the organopolysiloxane is a polydimethylsiloxane containing vinyl groups at both ends, and the content of the vinyl groups can be from 0.02 mmol / g to 0.2 mmol / g, from 0.1 mmol / g to 0.2 mmol / g, or from 0.15 mmol / g to 0.2 mmol / g.

[0040] Furthermore, one or two hydrogen groups (-H) of the silane derivative can be replaced by alkyl groups having one or two carbon atoms.

[0041] Furthermore, the Si-H content of the silane or silane derivative may be from 4 mmol / g to 16 mmol / g, from 4 mmol / g to 10 mmol / g, or from 4 mmol / g to 5 mmol / g.

[0042] Furthermore, the molar ratio of the Si-H of the silane or silane derivative to the vinyl groups contained at both ends of the compound selected from the group consisting of organopolysiloxane, chlorosilane, alkylalkoxysilane, sulfursilane, aminosilane, epoxysilane, and mixtures thereof can be from 1 to 3.

[0043] Furthermore, the thickness of the adhesive layer can be 15μm to 50μm, 18μm to 35μm, or 20μm to 25μm.

[0044] Furthermore, the thickness of the substrate layer can be 25μm to 100μm, 33μm to 70μm, or 38μm to 50μm.

[0045] Furthermore, the conductive layer can be gravure-coated onto the substrate layer.

[0046] Furthermore, the conductive layer can be dried for 30 to 90 seconds using hot air at 60°C to 100°C or 20Hz to 35Hz.

[0047] Furthermore, the adhesive layer can be applied to the conductive layer using a slit-type coating or a scraper-type coating.

[0048] Furthermore, the adhesive layer can be dried for 90 to 180 seconds using hot air at 60°C to 150°C or 30 to 35 Hz.

[0049] The effects of the invention

[0050] Based on the technical means of solving the problem according to the present invention as described above, various effects including the following can be expected. However, the present invention does not necessarily require all of the effects described below to be effective.

[0051] The electrostatic chuck film of the present invention is prepared in the order of substrate layer-conductive layer-adhesive layer. By appropriately adjusting the electrical and physical properties such as surface resistance, dielectric loss and dielectric constant, as well as the thickness of each layer, it can be picked up by electrostatic chuck under vacuum.

[0052] In particular, if the electrostatic chuck film of the present invention is attached to an electrostatic chuck, the other side can be bonded to products such as semiconductor wafers. Wafers with the electrostatic chuck film of the present invention attached can be easily peeled off by the electrostatic chuck under vacuum conditions as needed, and the electrostatic chuck film of the present invention can be removed outside the vacuum conditions, thereby having the advantage of not causing a decrease in the function of the product. Attached Figure Description

[0053] Figure 1 A cross-sectional view is shown to illustrate an embodiment of the present invention.

[0054] Figure 2 A cross-sectional view illustrating another embodiment of the present invention. Detailed Implementation

[0055] The preferred embodiments of the present invention will be described in detail below.

[0056] However, the following are merely examples and detailed descriptions of specific embodiments. The invention can be modified in various ways and has various forms; therefore, the invention is not limited to the specific embodiments described. It should be understood that the invention includes all modifications, equivalents, and substitutions encompassed by the spirit and scope of the invention.

[0057] Furthermore, in the following description, many specific details, such as specific structural elements, are described only to facilitate a more comprehensive understanding of the invention. It will be apparent to those skilled in the art that the invention can be practiced even without such specific details. Moreover, in describing the invention, detailed descriptions of relevant well-known functions or structures will be omitted when it is determined that such detailed descriptions would unnecessarily obscure the essence of the invention.

[0058] Furthermore, the terminology used in this invention is for describing specific embodiments only and is not intended to limit the invention. Unless otherwise defined, the terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms as defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and are not to be construed as having an overly formal meaning unless explicitly defined herein.

[0059] In this invention, unless the context clearly indicates otherwise, the singular expression includes the plural expression.

[0060] In this invention, unless otherwise stated, % means weight, and molecular weight not specifically specified means weight-average molecular weight.

[0061] In this invention, terms such as "first," "second," etc., can be used to describe various structural elements, but the structural elements should not be limited by these terms. The terms are used only to distinguish one structural element from others. For example, without departing from the scope of the claims, a first structural element can be named a second structural element, and similarly, a second structural element can be named a first structural element.

[0062] In this invention, terms such as “comprising,” “containing,” or “having” are intended to indicate the presence of features, structural elements (or components) described in the specification, and do not imply the absence or inability to add one or more other features or structural elements.

[0063] When a pickable adhesive film is attached to products such as semiconductor wafers using an electrostatic chuck, it can be easily peeled off even in a vacuum, and the film can be removed outside of a vacuum, thereby preventing functional degradation of the wafer, etc. The object of the present invention is to provide an electrostatic chuck film that exhibits these advantages.

[0064] In order to achieve the objectives described above, such as Figure 1 As shown, the electrostatic chuck film of the present invention is characterized by comprising: a substrate layer 10; a conductive layer 20 formed on the substrate layer 10; and an adhesive layer 30 formed on the conductive layer 20. A key feature of the present invention is the arrangement of the layers in the aforementioned order.

[0065] Furthermore, the substrate layer 10 may be selected from the group consisting of polyethylene terephthalate, polyethylene, polyimide, acrylic resin, cyclic olefin polymers, mixtures thereof, and copolymers thereof.

[0066] And, as Figure 2 As shown, the electrostatic chuck film of the present invention may further include a release film 40 formed on the adhesive layer 30.

[0067] Furthermore, when a voltage of 1kV is applied to the electrostatic chuck film, the surface resistance can be 1×10⁻⁶. 11 Ω / sq up to 1×10 13 Ω / sq. When the value is less than the specified range, the dielectric loss increases, rendering it unusable as an electrostatic chuck. Conversely, when the value is greater than the specified range, although the dielectric loss decreases, the reduced electron mobility renders it unusable as an electrostatic chuck.

[0068] Furthermore, when a voltage of 1 kV is applied to the laminate of the substrate layer 10 and the conductive layer 20, the surface resistance can be 1 × 10⁻⁶.3 Ω / sq up to 1×10 7 Ω / sq. When the value is less than the specified range, the dielectric loss increases, rendering it unusable as an electrostatic chuck. Conversely, when the value is greater than the specified range, although the dielectric loss decreases, the reduced electron mobility renders it unusable as an electrostatic chuck.

[0069] Furthermore, when a voltage of 1 kV is applied to the adhesive layer 30, the surface resistance can be greater than 1 × 10⁻⁶. 13 Ω / sq, when it is 1×10 13 When the dielectric strength is below Ω / sq, it cannot function as an electrostatic chuck due to increased dielectric loss.

[0070] Furthermore, under conditions of 25°C and 10GHz, the dielectric loss of the electrostatic chuck film can be from 0.02 to 0.1. When it is less than this range, the reduced electron mobility prevents the formation of an environment capable of generating positive charges and electrostatic forces within the electrostatic chuck, thus rendering it unable to function as an electrostatic chuck. Conversely, when it is greater than this range, the increased electron mobility leads to increased loss of negative charges before generating electrostatic forces with the electrostatic chuck, thus also preventing it from functioning as an electrostatic chuck.

[0071] Furthermore, under conditions of 25°C and 10 GHz, the dielectric loss of the laminate of the substrate layer and the conductive layer can be from 0.1 to 0.23. When the dielectric loss is less than this range, due to the small dielectric loss, there may be a problem where the electrostatic chuck does not separate from the electrostatic chuck when the applied voltage is turned off, due to the possible residual positive or negative charge on the electrostatic chuck. Conversely, when the dielectric loss is greater than this range, the electrostatic attraction is reduced or disappears because fewer electrons can bind to the electrostatic chuck.

[0072] Furthermore, under conditions of 25°C and 10 GHz, the dielectric loss of the laminate of the substrate layer and the adhesive layer can be from 0.007 to 0.009. When the dielectric loss is less than this range, due to the low dielectric loss, there may be a problem where the electrostatic chuck does not separate due to the possible residual positive or negative charge on the chuck when the applied voltage is turned off. Conversely, when the dielectric loss is greater than this range, the electrostatic attraction is reduced or disappears because fewer electrons can bind to the chuck.

[0073] Furthermore, under conditions of 25°C and 10GHz, the dielectric constant of the electrostatic chuck film can be between 2.8 and 3.3. When it is less than this range, the low dielectric constant prevents the generation of electrostatic force with the electrostatic chuck; conversely, when it is greater than this range, the high dielectric constant fails to ensure electron mobility, thus preventing the generation of electrostatic force with the electrostatic chuck.

[0074] Furthermore, under conditions of 25°C and 10GHz, the dielectric constant of the laminate of the substrate layer and the conductive layer can be between 3.0 and 3.5. When the dielectric constant is less than this range, the electrostatic attraction may be weak or absent due to the small amount of charge that can be stored. Conversely, when the dielectric constant is greater than this range, the large amount of charge that can be stored may result in the product not separating from the electrostatic chuck or being attracted by the electrostatic chuck even when the applied voltage is off.

[0075] Furthermore, under conditions of 25°C and 10 GHz, the dielectric constant of the laminate of the substrate layer and the adhesive layer can be between 2.9 and 3.2. When the dielectric constant is less than this range, the electrostatic attraction may be low or absent due to the small amount of charge that can be stored. Conversely, when the dielectric constant is greater than this range, the large amount of charge that can be stored may result in the product not separating from the electrostatic chuck or being attracted by the electrostatic chuck even when the applied voltage is off.

[0076] The main feature of this invention is that by precisely controlling the electrical and physical properties of each layer and the electrostatic chuck film that combines them, such as surface resistance, dielectric loss, or dielectric constant, it can be used as an electrostatic chuck for pickup.

[0077] Furthermore, the conductive layer 20 can be selected from the group consisting of poly(3,4-ethylenedioxythiophene) (PEDOT), poly(3,4-ethylenedioxythiophene)-polystyrenesulfonate (PEDOT-PSS), carbon nanotubes (CNTs), graphene, indium tin oxide (ITO), silver nanowires, and combinations thereof. A characteristic of the conductive layer 20 constituting the present invention is that, in addition to the aforementioned electrophysical properties, it must also possess transparency.

[0078] Furthermore, in the electrostatic chuck film of the present invention, when the adhesive layer 30 is formed on the conductive layer 20, part of the conductive layer 20 may be removed due to the solvent that dissolves the substance constituting the adhesive layer 30. This occurs when slit coating or blade coating is performed to form an adhesive layer 30 of a specified thickness. To prevent this, it is necessary to improve the solvent resistance of the conductive layer 20.

[0079] To improve the solvent resistance, a reaction between functional groups in the constituent materials of the conductive layer 20 can be induced, or a cross-linking reaction can be induced by introducing an additional cross-linking agent.

[0080] For example, when the conductive layer 20 of the present invention is a mixture of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) and water-dispersible polyurethane, a crosslinking reaction can be carried out by introducing an aziridine compound as a crosslinking agent.

[0081] Furthermore, the aziridine compound may be selected from the group consisting of trimethylolpropane tris(2-methyl-1-aziridine)propionate, trimethylolpropane tris[3-(aziridin-1-yl)propionate], pentaerythritol tris[3-(1-aziridinyl)propionate], pentaerythritol tris(2-methyl-1-aziridine propionate) and mixtures thereof.

[0082] Furthermore, the weight ratio of polyurethane to poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) (PEDOT-PSS) in the conductive layer 20 can be 1:9, 1.5:8.5, or 3:7. When the content of PEDOT-PSS is less than the aforementioned range, the surface resistance, dielectric loss, and dielectric constant requirements for functioning as an electrostatic chuck may not be met. Conversely, when the content is greater than the aforementioned range, although the physical properties may be met, the small amount of polyurethane may prevent sufficient crosslinking with the aziridine crosslinking agent. Therefore, not only is solvent resistance not guaranteed, but it is also not economically ideal.

[0083] Furthermore, the weight ratio of the mixture of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) and water-dispersible polyurethane in the conductive layer 20 to the aziridine compound can be 100:8 to 63, 100:10 to 63, or 100:12 to 63. When the weight ratio of the aziridine compound is less than the stated range, solvent resistance cannot be ensured because the carboxyl groups of the water-dispersible polyurethane are not sufficiently crosslinked. Conversely, when the weight ratio is greater than the stated range, unreacted aziridine compounds may migrate over time and temperature, which is not economically desirable.

[0084] Furthermore, the mixture of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) and water-dispersible polyurethane in the conductive layer 20 can be a solution dissolved in a solvent selected from the group consisting of water, ethanol, methanol, isopropanol and mixtures thereof.

[0085] Furthermore, the solution may also contain a stabilizer selected from the group consisting of ethylene glycol, sorbitol, and mixtures thereof.

[0086] Furthermore, the concentration of the mixture of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) and polyurethane dissolved in a solvent selected from the group consisting of water, ethanol, methanol, isopropanol, and mixtures thereof can be from 0.8% to 1.2% by weight or from 0.8% to 0.9% by weight. When the concentration of the solution is less than the range, coating streaks may appear on the coating surface because PEDOT-PSS particles may be exposed on the surface. Conversely, when the concentration is greater than the range, the surface may become uneven due to the fluidity of the coating liquid on the coating surface when the wet thickness is increased because of the reduced solids content.

[0087] Furthermore, the thickness of the conductive layer 20 can be from 0.03 μm to 3 μm. When the thickness of the conductive layer is less than this range, it may not function as an electrostatic chuck due to high surface resistance and reduced dielectric loss. Conversely, when the thickness is greater than this range, it may not function as an electrostatic chuck due to decreased surface resistance and increased dielectric loss.

[0088] Furthermore, the adhesive layer 30 may be selected from the group consisting of organosilicon, acrylic resin, urethane resin, rubber, and combinations thereof.

[0089] Furthermore, the adhesive layer 30 can be formed by reacting a compound with vinyl groups at both ends, selected from the group consisting of organopolysiloxane, chlorosilane, alkylalkoxysilane, sulfursilane, aminosilane, epoxysilane, and mixtures thereof, with a silane or silane derivative, preferably using platinum as a catalyst. A key feature of this invention is the specific application of an addition reaction (curing) step to improve the degree of curing and reduce the dielectric constant.

[0090] Furthermore, the organopolysiloxane is a polydimethylsiloxane containing vinyl groups at both ends, with a molecular weight of 600,000 to 700,000 by weight average and 300,000 to 400,000 by number average. The vinyl content can be 0.02 mmol / g to 0.2 mmol / g, 0.1 mmol / g to 0.2 mmol / g, or 0.15 mmol / g to 0.2 mmol / g. When the vinyl content is less than the range, it may not function as an electrostatic chuck due to insufficient cross-linking with Si-H, and therefore may fail to function as an electrostatic chuck as the dielectric loss increases. Conversely, when the content is greater than the range, the cross-linking density with Si-H increases, and therefore may fail to function as an electrostatic chuck as the dielectric loss increases.

[0091] Furthermore, one or two hydrogen groups (-H) of the silane derivative can be replaced by alkyl groups having one or two carbon atoms.

[0092] Furthermore, the Si-H content of the silane or silane derivative can be from 4 mmol / g to 16 mmol / g, 4 mmol / g to 10 mmol / g, or 4 mmol / g to 5 mmol / g. When the Si-H content is less than the range, it may lead to increased dielectric loss due to insufficient crosslinking with vinyl groups; conversely, when it is greater than the range, it may lead to migration to the adhesive layer surface due to the generation of unreacted Si-H groups.

[0093] Preferably, in the silane or silane derivative, one or two hydrogen groups (-H) of the hydrosiloxane copolymer can be replaced by an alkyl group having one or two carbon atoms. More preferably, the silane or silane derivative can be an alkylhydrosiloxane-dialkylsiloxane copolymer, and even more preferably, it can be a methylhydrosiloxane-dimethylsiloxane copolymer.

[0094] Furthermore, the molar ratio (Si-H / vinyl) of the Si-H of silanes or silane derivatives to the vinyl groups at both ends of compounds selected from the group consisting of organopolysiloxanes, chlorosilanes, alkylalkoxysilanes, sulfursilanes, aminosilanes, epoxysilanes, and mixtures thereof can be from 1 to 3. When the Si-H / vinyl molar ratio is greater than the range described above, although the crosslinking density increases, out-gassing occurs due to the hydrogen gas generated when the unreacted Si-H increases. Conversely, when the ratio is less than the range described above, the crosslinking density and dielectric constant decrease due to the reduced number of crosslinking points with vinyl groups, and the dielectric loss increases, thus preventing it from functioning as an electrostatic chuck.

[0095] Furthermore, the thickness of the adhesive layer 30 can be 15μm to 50μm, 18μm to 35μm, or 20μm to 25μm. When the thickness of the adhesive layer 30 is less than the range, it may fail to function as an electrostatic chuck due to increased dielectric loss; conversely, when it is greater than the range, it may fail to function as an electrostatic chuck due to decreased dielectric loss.

[0096] Furthermore, the thickness of the substrate layer 10 can be 25μm to 100μm, 33μm to 70μm, or 38μm to 50μm. When the thickness of the substrate layer 10 is less than the range, wrinkles may appear due to shrinkage during the thermal process of coating, which may result in poor appearance. Conversely, when the thickness is greater than the range, the dielectric loss may be reduced, which may prevent it from functioning as an electrostatic chuck.

[0097] The main feature of this invention is that by precisely controlling the thickness of each layer constituting the invention, it can function as an electrostatic chuck.

[0098] Furthermore, the conductive layer 20 can be gravure-coated onto the substrate layer 10.

[0099] Furthermore, the conductive layer 20 can be dried for 30 to 90 seconds using hot air at 60°C to 100°C or 20Hz to 35Hz. When the drying time or temperature is less than the range, insufficient drying may lead to incomplete curing or solvent evaporation, which could affect electrical physical properties such as capacitance.

[0100] Furthermore, the adhesive layer 30 can be applied to the conductive layer 20 by slit coating or by scraper coating.

[0101] Furthermore, the adhesive layer 20 can be dried for 90 to 180 seconds using hot air at 60°C to 150°C or 30Hz to 35Hz. When the drying time or temperature is less than the range, insufficient drying may lead to incomplete curing or solvent evaporation, which could affect electrical and physical properties such as capacitance.

[0102] The embodiments of the present invention will be described below.

[0103] Example

[0104] Preparation example: conductive layer

[0105] At ambient temperature and pressure, an aqueous solution of a mixture of 0.8 wt% poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) (PEDOT-PSS) and water-dispersible polyurethane (PEDOT-PSS: polyurethane = 1:9 wt) and pentaerythritol tris[3-(1-aziridinyl)propionate] at different concentrations (0 wt%, 0.05 wt%, 0.09 wt%, 0.1 wt%, 0.3 wt%, 0.5 wt%, and 0.6 wt%) was gravure-coated onto a 50 μm thick polyethylene terephthalate substrate. The substrate was then dried with hot air at 35 Hz at 60 °C for 20 seconds, at 80 °C for 20 seconds, and at 100 °C for 20 seconds to form a conductive layer with a thickness of 0.03 μm.

[0106] Test Example 1: Solvent Resistance of the Conductive Layer

[0107] When a voltage of 1 kV was applied, the surface resistance of the conductive layer in the prepared example was measured using a surface resistance meter (Wolfgang, Germany). Microfiber cloth soaked in methyl ethyl ketone (MEK) or ethanol was wound around an 800 g steel rod and brought into contact with the surface of the conductive layer. A 300 g weight was then placed on the steel rod and rubbed unidirectionally for 15 cm. This process was repeated 3, 5, 7, 10, 15, and 20 times. Then, when a voltage of 1 kV was applied, the surface resistance of the conductive layer was measured again using the surface resistance meter (Wolfgang, Germany). The results are shown in Table 1.

[0108] Table 1

[0109]

[0110] In Table 1, when the concentration of pentaerythritol tris[3-(1-aziridinyl)propionate] was 0.6 wt%, surface gelation occurred and the appearance was poor. The test results showed that when the concentration of pentaerythritol tris[3-(1-aziridinyl)propionate] was between 0.1 wt% and 0.5 wt%, it maintained a low surface resistivity even after repeated rubbing with solvent, thus indicating solvent resistance.

[0111] Examples 1 to 8, Comparative Examples 1 and 2: Conductive layer + adhesive layer

[0112] At room temperature and pressure, 27g of polydimethylsiloxane (weight average molecular weight 650,000) containing 0.2 mmol / g vinyl at both ends and 3g of methylhydrosiloxane-dimethylsiloxane copolymer (weight average molecular weight about 2,500) containing 4 mmol / g Si-H were reacted with 0.5g / kg platinum aqueous solution in 9.5g / kg toluene as a catalyst and slit-coated onto the conductive layer of the preparation example. The product was then dried with hot air at 35 Hz at 60°C for 50 seconds, at 110°C for 50 seconds, and at 150°C for 50 seconds to form an adhesive layer with a thickness of 20 μm (Example 1). The thickness of the conductive layer was changed to 0.02 μm (Comparative Example 1), 0.09 μm (Example 2), 0.15 μm (Example 3), 0.3 μm (Example 4), 0.9 μm (Example 5), 1.5 μm (Example 6), 2 μm (Example 7), 3 μm (Example 8), or 3.4 μm (Comparative Example 2) and an adhesive layer was formed.

[0113] Experimental Example 2: Surface resistivity varies with the thickness of the conductive layer

[0114] When the Si-H / vinyl group molar ratio was 2 and the applied voltage was 1 kV, the surface resistance of Examples 1 to 8, Comparative Example 1 and Comparative Example 2 were measured using a surface resistance meter (Mitsubishi Chemical, Japan). The results are shown in Table 2.

[0115] Table 2

[0116] Conductive layer thickness (μm) Surface resistivity (Ω / sq) Comparative Example 1 0.02 <![CDATA[1.32×10 13 ]]> Example 1 0.03 <![CDATA[7.54×10 12 ]]> Example 2 0.09 <![CDATA[4.13×10 12 ]]> Example 3 0.15 <![CDATA[1.39×10 12 ]]> Example 4 0.3 <![CDATA[9.81×10 11 ]]> Example 5 0.9 <![CDATA[8.84×10 11 ]]> Example 6 1.5 <![CDATA[5.93×10 11 ]]> Example 7 2 <![CDATA[4.39×10 11 ]]> Example 8 3 <![CDATA[3.82×10 11 ]]> Comparative Example 2 3.4 <![CDATA[2.83×10 10 ]]>

[0117] Experimental results confirmed that when the thickness of the conductive layer is between 0.03 μm and 0.3 μm, the surface resistivity is within 1 × 10⁻⁶. 11 Ω / sq up to 1×10 13 Within the target range of Ω / sq.

[0118] Experimental Example 3: Electrophysical Properties Based on Changes in the Molar Ratio of Si-H / Ethylene

[0119] When the molar ratio of Si-H of the methylsilane in Example 1 to the vinyl groups contained at both ends of the polydimethylsiloxane was changed to 0.5 (Comparative Example 3), 1 (Example 9), 3 (Example 10), or 4 (Comparative Example 4), the surface resistance was measured using a surface resistance meter (Mitsubishi Chemical, Japan), and the dielectric loss and dielectric constant changes at 10 GHz were measured using a dielectric meter (Keysight Technologies, USA) to confirm whether it functioned as an electrostatic chuck. The results are then shown in Table 3.

[0120] Table 3

[0121] Comparative Example 3 Example 9 Example 10 Comparative Example 4 Si-H / vinyl molar ratio 0.5 1 3 4 Surface resistivity (Ω / sq) <![CDATA[1.13×10 12 ]]> <![CDATA[4.43×10 11 ]]> <![CDATA[5.21×10 12 ]]> <![CDATA[7.23×10 12 ]]> Dielectric loss 0.052 0.043 0.032 0.018 Dielectric constant 3.5 3.2 2.89 2.75 electrostatic chuck Can't Can Can Can't

[0122] The test results confirmed that when the molar ratio of Si-H / vinyl is 1 to 3, the dielectric loss value and dielectric constant value are within the target range of 0.02 to 0.1 and 2.8 to 3.3, respectively.

[0123] Experimental Example 4: Changes in Electrical Physical Properties Based on Layer Sequence

[0124] The same process as in Example 1 was performed, but the adhesive layer was formed below the substrate layer instead of on the conductive layer (Comparative Example 5), or after preparation according to Example 1, a conductive layer was further formed below the substrate layer (Comparative Example 6). The dielectric loss and dielectric constant changes at 10 GHz were then measured using a dielectric constant meter (Keysight Technologies, USA) to confirm whether it functioned as an electrostatic chuck, and the results are shown in Table 4. In this case, the Si-H / vinyl alcohol molar ratio was 2, and the thickness of the conductive layer was 0.3 μm.

[0125] Table 4

[0126] Comparative Example 5 Comparative Example 6 Example 11 Layer order Conductive / Substrate / Adhesive Conductive / Substrate / Conductive / Adhesive Substrate / Conductive / Adhesive Dielectric loss 0.127 0.133 0.084 Dielectric constant 3.31 3.33 3.15 electrostatic chuck Can't Can't Can

[0127] The test results confirmed that only when the substrate layer-conductive layer-adhesive layer were prepared in the order of substrate layer-conductive layer-adhesive layer, the dielectric loss value and dielectric constant value were within the target range of 0.02 to 0.1 and 2.8 to 3.3, respectively.

[0128] The preferred embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. Naturally, those skilled in the art can make various modifications and implementations without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as limited to the above embodiments, but should be determined by the scope of protection described below and its equivalents.

[0129] Explanation of reference numerals in the attached figures

[0130] 10: Substrate layer; 20: Conductive layer

[0131] 30: Adhesive layer; 40: Release film.

Claims

1. An electrostatic chuck film, comprising: Substrate layer; A conductive layer is formed on the substrate layer; as well as An adhesive layer is formed on the conductive layer.

2. The electrostatic chuck film according to claim 1, characterized in that, It also includes a release film formed on the adhesive layer.

3. The electrostatic chuck film according to claim 1, characterized in that, When a voltage of 1 kV is applied to the electrostatic chuck film, the surface resistance is 1 × 10⁻⁶. 11 Ω / sq up to 1×10 13 Ω / sq.

4. The electrostatic chuck film according to claim 1, characterized in that, When a voltage of 1 kV is applied to the electrostatic chuck film, the dielectric loss is 0.02 to 0.1 kV.

5. The electrostatic chuck film according to claim 1, characterized in that, When a voltage of 1 kV is applied to the electrostatic chuck film, the dielectric constant is 2.8 to 3.

3.

6. The electrostatic chuck film according to claim 1, characterized in that, The conductive layer is selected from the group consisting of poly(3,4-ethylenedioxythiophene)PEDOT, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid)PEDOT-PSS, carbon nanotubes (CNTs), graphene, indium tin oxide (ITO), silver nanowires, and combinations thereof.

7. The electrostatic chuck film according to claim 1, characterized in that, The adhesive layer is selected from the group consisting of organosilicon, acrylic resin, urethane resin, rubber, and combinations thereof.

8. The electrostatic chuck film according to claim 1, characterized in that, The thickness of the substrate layer is 25 μm to 100 μm, 33 μm to 70 μm, or 38 μm to 50 μm.

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