JP5819895B2 - Electrostatic chuck - Google Patents

Description

  The present invention relates to an electrostatic chuck.

  Conventionally, as a manufacturing method of an electrostatic chuck, a manufacturing method of an electrostatic chuck having a two-layer structure or a manufacturing method of an electrostatic chuck having a three-layer structure is known.

  As the former, a step of forming an alumina sintered body, a step of printing an electrode paste for electrostatic electrodes on the alumina sintered body, and filling the electrode paste with alumina granulated powder to mold A manufacturing method including a process and a process of firing a molded body integrated in a mold forming process is known (see Patent Document 1). In this patent document 1, it is also disclosed that an alumina calcined body is used instead of the alumina sintered body. Since alumina powder contains a binder, this alumina powder is usually referred to as alumina granulated powder.

  On the other hand, as the latter, a process of printing an electrode paste for electrostatic electrodes on the upper surface of the alumina sintered body and printing an electrode paste for heater electrodes on the lower surface, and calcining the alumina sintered body after the printing And a step of placing alumina granulated powder on the electrostatic electrode and placing the alumina granulated powder under the heater electrode, press-molding them in that state, and subjecting them to pressure firing A manufacturing method is known (see Patent Document 2). The alumina powder is usually called alumina granulated powder because it is used after being mixed with a binder and spray-dried with a spray dryer.

JP 2005-343733 A JP 2008-47885 A

  However, in the manufacturing methods of Patent Documents 1 and 2, since the alumina granulated powder is placed on the electrostatic electrode and pressed and then fired, the end face of the electrostatic electrode may be deformed and sharpened at an acute angle. . Such a sharp shape tends to cause cracks due to stress concentration, electric field concentration, and the like, and it is difficult to sufficiently ensure the durability of the product.

  The present invention has been made to solve such a problem, and a main object thereof is to suppress deformation of the end face of the electrostatic electrode.

The manufacturing method of the first electrostatic chuck of the present invention is as follows:
This is an electrostatic chuck manufacturing method in which an electrostatic chuck is manufactured by hot-press firing a laminated calcined body in which a pair of ceramic calcined bodies are superposed so as to sandwich an electrostatic electrode of a predetermined shape or a precursor thereof. And
(A) A ceramic slurry containing ceramic powder, a solvent, a dispersant and a gelling agent is poured into a first mold in which the electrostatic electrode or its precursor is detachably attached to the inner surface, and the gelling agent is chemically treated. Producing a ceramic molded body with an embedded electrode in which the electrostatic electrode or its precursor is embedded in a first ceramic molded body by gelling the ceramic slurry after reacting, and then releasing;
(B) producing a second ceramic molded body;
(C) producing the laminated calcined body using the ceramic molded body with embedded electrodes and the second ceramic molded body, and hot-press firing the laminated calcined body;
Is included.

  According to this method of manufacturing an electrostatic chuck, it is possible to suppress deformation of the end face of the electrostatic electrode having a predetermined shape. Specifically, in the step (a), when the ceramic slurry is poured into a first mold in which an electrostatic electrode or a precursor thereof is detachably attached to the gel, the slurry in the initial reaction has low viscosity and fluidity. Therefore, the edge of the electrostatic electrode or the precursor thereof can be prevented from being scraped, and the ceramic powder can be uniformly and uniformly filled in the electrode interface. It is thought that deformation can be suppressed. Incidentally, the precursor of an electrostatic electrode refers to a material that becomes an electrostatic electrode by hot-press firing, for example, a material obtained by printing an electrode paste in the shape of an electrostatic electrode (the same applies hereinafter).

  In the first method for producing an electrostatic chuck of the present invention, in the step (b), a ceramic slurry containing a ceramic powder, a solvent, a dispersant and a gelling agent is poured into the second mold, and the gelling agent is used. You may produce the said 2nd ceramic molded object by carrying out a chemical reaction and gelatinizing after making the said ceramic slurry gel. In this way, the density becomes the same as that of the ceramic molded body with embedded electrodes, the warpage of the laminated sintered body after the hot press firing is reduced, the variation in the distance between the wafer loading surface and the electrostatic electrode is reduced, and consequently the wafer. There is an effect that the in-plane variation of the adsorption force when chucking is reduced.

  In the first method for producing an electrostatic chuck according to the present invention, in the step (b), an integration mold is prepared, and a surface of the ceramic molded body with embedded electrodes opposite to the electrode formation surface is integrated. A ceramic slurry containing ceramic powder, a solvent, a dispersing agent and a gelling agent is then detachably attached to the inner surface of the molding die for casting, and the ceramic slurry is poured into the integrating molding die and chemically reacted with the gelling agent. In the step (c), the ceramic molded body with embedded electrodes and the second ceramic molded body are laminated from the integration mold. The composite body may be taken out and the laminated composite body may be calcined to produce the laminated calcined body. In this way, since the laminated composite can be obtained simultaneously with the production of the second ceramic molded body, compared with the case where the step of producing the second ceramic molded body and the step of producing the laminated composite are performed separately, The number of processes is reduced. The size of the internal space of the integration mold may be determined in consideration of the contraction rate with respect to the electrostatic chuck, for example.

  In the first method for producing an electrostatic chuck according to the present invention, in the step (a), the ceramic molded body with embedded electrodes is calcined to form a ceramic calcined body with embedded electrodes, and after the step (b), The ceramic calcined body with embedded electrode may be used instead of the ceramic molded body with embedded electrode. Also in this method, the density difference in the laminated body before the hot press firing is reduced, thereby reducing the warpage of the laminated sintered body after the hot press firing, and the in-plane of the attractive force when chucking the wafer. There is an effect that variation is reduced.

The manufacturing method of the second electrostatic chuck of the present invention is as follows:
This is an electrostatic chuck manufacturing method in which an electrostatic chuck is manufactured by hot-press firing a laminated calcined body in which a pair of ceramic calcined bodies are superposed so as to sandwich an electrostatic electrode of a predetermined shape or a precursor thereof. And
(A) A ceramic slurry containing ceramic powder, a solvent, a dispersant and a gelling agent is poured into a first mold in which convex portions having the same shape as the electrostatic electrode or the precursor thereof are provided on the inner surface in a non-detachable manner, The ceramic slurry is gelled by chemically reacting with the gelling agent, and then released, thereby producing a first ceramic molded body having a concave portion corresponding to the convex portion, and the electrostatic electrode in the concave portion. Or producing a ceramic molded body with embedded electrodes by forming a precursor thereof;
(B) producing a second ceramic molded body;
(C) producing the laminated calcined body using the ceramic molded body with embedded electrodes and the second ceramic molded body, and hot-press firing the laminated calcined body;
Is included.

  This electrostatic chuck manufacturing method can also suppress the deformation of the end face of the electrostatic electrode having a predetermined shape. Specifically, in the step (a), a first ceramic molded body having a recess is manufactured, and an electrostatic electrode or a precursor thereof is formed in the recess, thereby manufacturing a ceramic body with an embedded electrode. Since the first ceramic molded body is made by gelling ceramic slurry in which ceramic powder is dispersed, the first ceramic molded body has strength compared to the case where it is made using ceramic granulated powder (described above), and in the concave portion. The end portion of the formed electrostatic electrode is not easily deformed. Further, since the electrostatic electrode or its precursor does not protrude to the outside, there is no possibility that the end portion of the electrostatic electrode or its precursor is rubbed with other members and deformed. Further, it is considered that the ceramic powder is uniformly filled in the electrode interface without any gap, and the deformation of the electrode can be suppressed during the hot press firing in the step (c). As a result of the above, it is considered that the end face of the electrostatic electrode having a predetermined shape could be suppressed from being deformed.

  In the second method for producing an electrostatic chuck of the present invention, in the step (b), a ceramic slurry containing a ceramic powder, a solvent, a dispersing agent and a gelling agent is poured into a second mold, and the gelling agent is used. You may produce the said 2nd ceramic molded object by carrying out a chemical reaction and gelatinizing after making the said ceramic slurry gel. In this way, the density becomes the same as that of the ceramic molded body with embedded electrodes, the warpage of the laminated sintered body after the hot press firing is reduced, the variation in the distance between the wafer loading surface and the electrostatic electrode is reduced, and consequently the wafer. There is an effect that the in-plane variation of the adsorption force when chucking is reduced.

  In the second method for producing an electrostatic chuck according to the present invention, in the step (b), an integration mold is prepared, and the surface opposite to the electrode formation surface of the ceramic molded body with embedded electrodes is integrated. A ceramic slurry containing ceramic powder, a solvent, a dispersing agent and a gelling agent is then detachably attached to the inner surface of the molding die for casting, and the ceramic slurry is poured into the integrating molding die and chemically reacted with the gelling agent. In the step (c), the ceramic molded body with embedded electrodes and the second ceramic molded body are laminated from the integration mold. The composite body may be taken out and the laminated composite body may be calcined to produce the laminated calcined body. In this way, since the laminated composite can be obtained simultaneously with the production of the second ceramic molded body, compared with the case where the step of producing the second ceramic molded body and the step of producing the laminated composite are performed separately, The number of processes is reduced. The size of the internal space of the integration mold may be determined in consideration of the contraction rate with respect to the electrostatic chuck, for example.

  In the second method for manufacturing an electrostatic chuck according to the present invention, in the step (a), the first ceramic molded body is pre-fired before the electrostatic electrode or the precursor thereof is formed in the recess. A ceramic calcined body with embedded electrodes may be obtained, and after the step (b), the ceramic calcined body with embedded electrodes may be used instead of the ceramic molded body with embedded electrodes. Also in this method, the density difference in the laminated body before the hot press firing is reduced, thereby reducing the warpage of the laminated sintered body after the hot press firing, and the in-plane of the attractive force when chucking the wafer. There is an effect that variation is reduced.

The manufacturing method of the third electrostatic chuck of the present invention is as follows:
This is an electrostatic chuck manufacturing method in which an electrostatic chuck is manufactured by hot-press firing a laminated calcined body in which a pair of ceramic calcined bodies are superposed so as to sandwich an electrostatic electrode of a predetermined shape or a precursor thereof. And
(A) producing a first ceramic molded body, and forming the electrostatic electrode or a precursor thereof on the surface of the first ceramic molded body to obtain a ceramic molded body with convex electrodes;
(B) A surface opposite to the electrode forming surface of the ceramic molded body with the convex electrode is detachably attached to the inner surface of the integration mold, and thereafter contains ceramic powder, a solvent, a dispersant, and a gelling agent. A ceramic slurry is poured into the integration mold, the gelling agent is chemically reacted to gel the ceramic slurry to produce a second ceramic molded body, and then released to form the ceramic mold with convex electrodes. Obtaining a laminated composite of a body and the second ceramic molded body;
(C) producing the laminated calcined body using the laminated composite, and hot-press firing the laminated calcined body;
Is included.

  This electrostatic chuck manufacturing method can also suppress the deformation of the end face of the electrostatic electrode having a predetermined shape. Specifically, in the step (b), after the ceramic molded body with a convex electrode is detachably attached to the inner surface of the integrating mold, the ceramic slurry is poured into the integrating mold and gelled. Since the slurry has low viscosity and high fluidity, it can prevent the electrostatic electrode of the ceramic body with a convex electrode or the end of its precursor from being scraped, and the ceramic powder is uniformly filled in the electrode interface without any gaps. It is considered that deformation of the electrode can be suppressed during the hot press firing in the step (c). The size of the internal space of the integration mold may be determined in consideration of the contraction rate with respect to the electrostatic chuck, for example.

  In the third method for producing an electrostatic chuck according to the present invention, in the step (a), a ceramic slurry containing ceramic powder, a solvent, a dispersing agent and a gelling agent is poured into the first mold, and the gelling agent is used. You may produce the said 1st ceramic molded object by carrying out a chemical reaction and gelatinizing after making the said ceramic slurry gel. If it carries out like this, it will become the same density as a 2nd ceramic molded object, the curvature of the laminated sintered compact after a hot press baking will become small, the variation in the distance of a wafer loading surface and an electrostatic electrode will become small, and a wafer will be chucked by extension. There is an effect that the in-plane variation of the attracting force becomes small.

  In the third method for producing an electrostatic chuck of the present invention, in the step (a), by calcining the first ceramic molded body before or after forming the electrostatic electrode or a precursor thereof on the surface, A ceramic calcined body with convex electrodes may be obtained, and after the step (b), the ceramic calcined body with convex electrodes may be used instead of the ceramic molded body with convex electrodes. Also in this method, the density difference in the laminated body before the hot press firing is reduced, thereby reducing the warpage of the laminated sintered body after the hot press firing, and the in-plane of the attractive force when chucking the wafer. There is an effect that variation is reduced.

  In the first to third methods for producing an electrostatic chuck according to the present invention, as a laminated calcined body, a pair of ceramic calcined bodies are superposed so as to sandwich an electrostatic electrode or a precursor thereof, and a heater electrode or its A structure in which a pair of ceramic calcined bodies are overlapped so as to sandwich the precursor may be used. In this case, for a structure in which a pair of ceramic calcined bodies are overlapped so as to sandwich a heater electrode or a precursor thereof, the electrostatic electrode or the Preferably, the precursor is replaced with a heater electrode or the precursor. If it carries out like this, it can suppress that the end surface of the heater electrode of a predetermined shape deform | transforms. One of the pair of ceramic calcined bodies that sandwich the electrostatic electrode or its precursor and one of the pair of ceramic calcined bodies that sandwich the heater electrode or its precursor may be used as a common member. That is, it is good also as a ceramic calcined body-electrostatic electrode-ceramic calcined body-heater electrode-ceramic calcined body.

  In the first to third electrostatic chuck manufacturing methods of the present invention, the ceramic powder preferably has an average particle size of 0.4 to 0.6 μm. In this way, the above-described effects can be obtained more remarkably. The reason is considered to be that the ceramic powder is uniformly filled in the electrode interface with no gap, and the deformation of the electrode can be suppressed during the hot press firing in the step (c).

  The electrostatic chuck of the present invention is an electrostatic chuck having an electrostatic electrode built therein, and the end surface of the electrostatic electrode is a flat surface or a bulging surface when viewed in a longitudinal section, and the bulging surface. The angle θ connecting the upper corner, the bulging tip and the lower corner is 160 ≦ θ <180 °.

  In this electrostatic chuck, since the end portion of the electrostatic electrode is not sharpened at an acute angle, stress is not easily concentrated. Therefore, cracks are hardly generated and the durability of the product can be sufficiently secured.

A vertical sectional view of the electrostatic chuck 10, and the inside of the circle is a partially enlarged view. It is a manufacturing process figure which shows an example of the manufacturing method of a 1st electrostatic chuck. It is a manufacturing process figure which shows another example of the manufacturing method of a 1st electrostatic chuck. It is a manufacturing process figure which shows another example of the manufacturing method of a 1st electrostatic chuck. It is a manufacturing process figure which shows another example of the manufacturing method of a 1st electrostatic chuck. It is a manufacturing process figure which shows an example of the manufacturing method of a 2nd electrostatic chuck. It is a manufacturing process figure which shows another example of the manufacturing method of a 2nd electrostatic chuck. It is a manufacturing process figure which shows an example of the manufacturing method of a 3rd electrostatic chuck. It is a manufacturing process figure which shows another example of the manufacturing method of a 3rd electrostatic chuck.

1. Preparation of ceramic molded body by gel cast method The gel cast method is a method in which a ceramic slurry containing ceramic powder, solvent, dispersant and gelling agent is poured into a mold, and the gelling agent is chemically reacted to gel the ceramic slurry. It refers to a method for producing a ceramic molded body by releasing after forming. The gel cast method is used at least in step (a) in the first and second electrostatic chuck manufacturing methods of the present invention and in step (b) in the third electrostatic chuck manufacturing method.

  The material of the ceramic powder may be an oxide ceramic or a non-oxide ceramic. Examples thereof include alumina, yttria, aluminum nitride, silicon nitride, silicon carbide, samaria, magnesia, magnesium fluoride, ytterbium oxide and the like. These materials may be used alone or in combination of two or more. The average particle diameter of the ceramic powder is not particularly limited as long as a uniform ceramic slurry can be prepared and produced, but is preferably 0.4 to 0.6 μm, and more preferably 0.45 to 0.55 μm.

  The solvent is not particularly limited as long as it dissolves the dispersant and the gelling agent. For example, hydrocarbon solvents (toluene, xylene, solvent naphtha, etc.), ether solvents (ethylene glycol monoethyl ether, butyl) Carbitol, butyl carbitol acetate, etc.), alcohol solvents (isopropanol, 1-butanol, ethanol, 2-ethylhexanol, terpineol, ethylene glycol, glycerin, etc.), ketone solvents (acetone, methyl ethyl ketone, etc.), ester solvents ( Butyl acetate, dimethyl glutarate, triacetin and the like) and polybasic acid solvents (glutaric acid and the like). In particular, it is preferable to use a solvent having two or more ester bonds such as a polybasic acid ester (for example, dimethyl glutarate) and an acid ester of a polyhydric alcohol (for example, triacetin).

  The dispersant is not particularly limited as long as the ceramic powder is uniformly dispersed in the solvent. For example, polycarboxylic acid copolymer, polycarboxylate salt, sorbitan fatty acid ester, polyglycerin fatty acid ester, phosphate ester salt copolymer, sulfonate copolymer, polyurethane polyester copolymer having tertiary amine A polymer etc. are mentioned. In particular, it is preferable to use a polycarboxylic acid copolymer, a polycarboxylate, or the like. By adding this dispersant, the slurry before molding can have a low viscosity and a high fluidity.

  As a gelatinizer, it is good also as what contains isocyanate, polyols, and a catalyst, for example. Among these, the isocyanate is not particularly limited as long as it is a substance having an isocyanate group as a functional group, and examples thereof include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and modified products thereof. In addition, in the molecule | numerator, reactive functional groups other than an isocyanate group may contain, and also many reactive functional groups may contain like polyisocyanate. The polyol is not particularly limited as long as it is a substance having two or more hydroxyl groups capable of reacting with an isocyanate group. For example, ethylene glycol (EG), polyethylene glycol (PEG), propylene glycol (PG), polypropylene glycol (PPG) , Polytetramethylene glycol (PTMG), polyhexamethylene glycol (PHMG), polyvinyl alcohol (PVA), and the like. Although it will not specifically limit if it is a substance which accelerates | stimulates urethane reaction of isocyanate and polyols as a catalyst, For example, a triethylenediamine, hexanediamine, 6-dimethylamino-1-hexanol etc. are mentioned.

  In the gel casting method, a slurry precursor is first prepared by adding a solvent and a dispersant to a ceramic powder at a predetermined ratio and mixing them over a predetermined time, and then the gel is added to the slurry precursor. It is preferable to add an agent and mix and vacuum degas to make a ceramic slurry. The mixing method for preparing the slurry precursor or slurry is not particularly limited, and for example, a ball mill, self-revolving stirring, vibration stirring, propeller stirring, or the like can be used. In addition, since the ceramic reaction which added the gelatinizer to the slurry precursor begins to advance the chemical reaction (urethane reaction) of a gelatinizer with time passage, it is preferable to pour into the mold quickly. The ceramic slurry poured into the mold is gelated by a chemical reaction of the gelling agent contained in the slurry. The chemical reaction of the gelling agent is a reaction of the isocyanate and the polyol as a gelling agent, and is a reaction in which the isocyanate and the polyol undergo a urethane reaction to become a urethane resin (polyurethane). The ceramic slurry is gelled by the reaction of the gelling agent, and the urethane resin functions as an organic binder.

2. Production of ceramic calcined body To produce a ceramic calcined body, the ceramic molded body is dried, degreased and then calcined.

  The ceramic molded body is dried to evaporate the solvent contained in the ceramic molded body. What is necessary is just to set a drying temperature and drying time suitably according to the solvent to be used. However, the drying temperature is set with care so that cracks do not occur in the ceramic molded body during drying. The atmosphere may be any of an air atmosphere, an inert atmosphere, and a vacuum atmosphere. The dimensions shrink by about 2% in the linear direction by drying.

  The ceramic molded body after drying is degreased in order to decompose and remove organic substances such as a dispersant and a catalyst. The degreasing temperature may be appropriately set according to the type of organic matter contained, but may be set to 400 to 600 ° C., for example. The atmosphere may be any of an air atmosphere, an inert atmosphere, and a vacuum atmosphere.

  The calcination of the ceramic body after degreasing is performed in order to increase the strength and facilitate handling. The calcining temperature is not particularly limited, but may be set to 750 to 900 ° C., for example. The atmosphere may be any of an air atmosphere, an inert atmosphere, and a vacuum atmosphere. The size shrinks about 1.5% in the linear direction by calcination.

3. Formation of Electrostatic Electrode The electrostatic electrode may be formed by adjusting the conductive material to a predetermined shape, or may be formed by baking the electrode paste after adjusting the electrode paste to a predetermined shape. In addition, what prepared the electrode paste in the predetermined shape is called the precursor of an electrostatic electrode. The electrode paste is not particularly limited, and may include, for example, a conductive material, ceramic powder, a binder, and a solvent. Examples of the conductive material include tungsten, tungsten carbide, platinum, silver, palladium, nickel, molybdenum, and the like. As ceramic powder, the powder which consists of a ceramic material of the same kind as a ceramic calcined body is mentioned, for example. Examples of the binder include ethyl cellulose, polymethyl methacrylate, polyvinyl butyral, and the like. Examples of the solvent include terpineol. Examples of the printing method include a screen printing method. Note that the electrostatic electrode paste and the heater electrode paste may have the same composition, but may have different compositions.

4). The hot press firing hot press firing, at least the maximum temperature (sintering temperature), it is preferable that the pressing pressure and 30~300kgf / cm ^2, and more preferably a 50~250kgf / cm ^2. Moreover, what is necessary is just to set the maximum temperature suitably with the kind of ceramic powder, a particle size, etc., but it is preferable to set to the range of 1000-2000 degreeC. The atmosphere may be appropriately selected from an air atmosphere, an inert atmosphere, and a vacuum atmosphere according to the type of ceramic powder. Shrink about 50% in the thickness direction by hot press firing.

5. Embodiment of Electrostatic Chuck FIG. 1 is a longitudinal sectional view of an electrostatic chuck 10, and the inside of a circle is a partially enlarged view. As shown in FIG. 1, the electrostatic chuck 10 includes an electrostatic electrode 14 and a heater electrode 16. The electrostatic electrode 14 is a disk-shaped electrode, and is provided on the side close to the wafer placement surface 10a. The heater electrode 16 is a linear member having two unillustrated points near the center as a start point and an end point. The heater electrode 16 is wired so as to reach the entire plane of the electrostatic chuck 10 from the start point in the manner of a single stroke, and then returns to the end point. It has become. Since FIG. 1 is a cross-sectional view of the electrostatic chuck 10, the heater electrode 16 appears discontinuously, but has a continuous line shape when seen in a plan view.

  Such an electrostatic chuck 10 is manufactured by any one of the first to third electrostatic chuck manufacturing methods of the present invention. In addition, the specific example of a manufacturing method is mentioned later.

  A partially enlarged view of the longitudinal section of the electrostatic electrode 14 of the electrostatic chuck 10 is shown in a circle in FIG. Here, the case where the end surface 14a of the electrostatic electrode 14 is a bulging surface is shown, and the angle θ is a straight line connecting the upper corner 14b and the bulging tip 14c of the end surface 14a, and the bulging tip 14c and the lower corner 14d of the end surface 14a. Is the angle formed by the straight line connecting The bulging tip 14c is a portion of the end surface 14a that protrudes to the outermost side. Here, the angle θ is 160 ° ≦ θ <180 °. Note that the end surface 14a of the electrostatic electrode 14 may be a flat vertical surface instead of a bulging surface. Since the end face of the heater electrode 16 is the same as the end face 14a of the electrostatic electrode 14, the description thereof is omitted. In addition, the electrostatic chuck produced by the manufacturing method of Patent Documents 1 and 2 may have an acute angle of 30 to 50 °.

  According to the electrostatic chuck 10 described above, since the end surfaces of the electrostatic electrode 14 and the heater electrode 16 are not sharp, the stress concentration and the electric field concentration are difficult to occur. Therefore, cracks are hardly generated and the durability of the product can be sufficiently secured.

  In addition, although the electrostatic chuck 10 described above includes the heater electrode 16, the heater electrode 16 may not be included.

6). Embodiment of Manufacturing Method of Each Electrostatic Chuck (1) Embodiment Related to Manufacturing Method of First Electrostatic Chuck The manufacturing method of the electrostatic chuck 10 will be described below with reference to FIG. FIG. 2 is a manufacturing process diagram showing an example of a manufacturing method of the first electrostatic chuck. In summary, as shown in FIG. 2 (j), this manufacturing method superimposes the first and second ceramic calcined bodies 51 and 52 so as to sandwich the electrostatic electrode precursor 24, and the heater electrode precursor. The electrostatic chuck 10 is manufactured by hot-press firing the laminated calcined body 50 in which the second and third ceramic calcined bodies 52 and 53 are superposed so as to sandwich the H.26. Hereinafter, a specific procedure will be described.

(1-1) Production of the first ceramic molded body 41 First, the first molding die 31 is prepared (see FIG. 2A). The first mold 31 has an internal space (an internal space slightly larger than that of the first ceramic calcined body 51) having a size in consideration of the shrinkage rate with respect to the first ceramic calcined body 51. Further, the inner surface is coated or lined with a fluororesin, and the detachability of the electrode and the molded body is good. Then, an electrode paste is screen-printed on the inner surface of the lower mold of the first mold 31 to form an electrostatic electrode precursor 24 having a size about several percent larger than the electrostatic electrode 14 in the line direction (FIG. 2B). )reference). The electrostatic electrode precursor 24 can be attached to and detached from the inner surface of the first mold 31 for coating or lining treatment with a fluorine resin. The outer peripheral surface of the electrostatic electrode precursor 24 is a flat vertical surface. Next, a ceramic slurry containing ceramic powder, a solvent, a dispersant, and a gelling agent is poured into the first mold 31, the gelling agent is chemically reacted to gel the ceramic slurry, and then released. Thereby, the 1st ceramic molded object 41 with which the electrostatic electrode precursor 24 was embedded, ie, the ceramic molded object 41X with an embedded electrode, is obtained (refer FIG.2 (c)). The electrostatic electrode precursor 24 has an upper surface and side surfaces covered with the first ceramic molded body 41, but the lower surface is exposed and forms the same plane as the lower surface of the first ceramic molded body 41.

(1-2) Production of Second Ceramic Molded Body 42 The second ceramic molded body 42 is produced separately from the first ceramic molded body 41. First, the 2nd shaping | molding die 32 is prepared (refer FIG.2 (d)). The second mold 32 has an internal space (an internal space slightly larger than that of the first ceramic calcined body 52) having a size in consideration of the shrinkage rate with respect to the second ceramic calcined body 52. Then, a ceramic slurry containing ceramic powder, a solvent, a dispersant, and a gelling agent is poured into the second mold 32, and the gelling agent is chemically reacted to gel the ceramic slurry and then released. Thereby, the 2nd ceramic molded object 42 is obtained (refer FIG.2 (e)).

(1-3) Production of Third Ceramic Molded Body 43 The third ceramic molded body 43 is produced separately from the first ceramic molded body 41 and the second ceramic molded body 42. First, the 3rd shaping | molding die 33 is prepared (refer FIG.2 (f)). The third mold 33 has an internal space (an internal space slightly larger than that of the first ceramic calcined body 53) having a size that takes into account the shrinkage rate with respect to the third ceramic calcined body 53. Further, the inner surface is coated or lined with a fluororesin, and the detachability of the electrode and the molded body is good. Then, the electrode paste is screen-printed on the inner surface of the upper mold of the third mold 33 to form the heater electrode precursor 26 having a size about several percent larger in the linear direction than the electrostatic electrode 16 (FIG. 2G). reference). The heater electrode precursor 26 can be attached to and detached from the inner surface of the third mold 33 for coating or lining treatment with a fluorine resin. Further, the side surface of the heater electrode precursor 26 is a vertical surface. Next, a ceramic slurry containing ceramic powder, a solvent, a dispersant, and a gelling agent is poured into the third mold 33, and the gelling agent is chemically reacted to gel the ceramic slurry and then released. Thereby, the 3rd ceramic molded object 43 with which the heater electrode precursor 26 was embedded, ie, the ceramic molded object 43X with an embedded electrode, is obtained (refer FIG.2 (h)). The heater electrode precursor 26 has a lower surface and side surfaces covered with the third ceramic molded body 43, but the upper surface is exposed and forms the same plane as the upper surface of the third ceramic molded body 43.

(1-4) Production of the electrostatic chuck 10 Next, the ceramic molded bodies 41X, 43X with embedded electrodes and the second ceramic molded body 42 are laminated to form a laminated molded body 40. Specifically, the electrostatic electrode precursor 24 is sandwiched between the first ceramic molded body 41 and the second ceramic molded body 42, and the heater electrode precursor is bonded between the second ceramic molded body 42 and the third ceramic molded body 43. By laminating so as to sandwich the body 26, a laminated molded body 40 is obtained (see FIG. 2 (i)). The laminated molded body 40 is dried, degreased, and further calcined to obtain a laminated calcined body 50 (see FIG. 2 (j)). And the electrostatic chuck 10 is obtained by carrying out the hot press baking of this laminated calcined body 50 (refer FIG.2 (k)).

(1-5) Effect According to the manufacturing method of the electrostatic chuck 10 described in detail above, it is possible to suppress deformation of the end surfaces of the electrostatic electrode 14 and the heater electrode 16 having a predetermined shape. Specifically, when the ceramic slurry is poured into a first mold 31 in which the electrostatic electrode precursor 24 is detachably attached to the inner surface for gelation, the slurry in the initial reaction has low viscosity and high fluidity. It can be considered that the end of the electrode or its precursor 24 can be prevented from being scraped, and the ceramic powder can be uniformly filled in the electrode interface without gaps, and deformation of the electrode can be suppressed during hot press firing. This also applies to the heater electrode precursor 26.

(1-6) Other Embodiments In the above-described embodiments, the first to third ceramic molded bodies 41 to 43 are laminated as they are without drying, degreasing, and calcining to form a laminated molded body 40, and this laminated molding is performed. The body 40 is dried, degreased, and calcined to obtain a laminated calcined body 50. If the laminated calcined body 50 is finally obtained, the first to third ceramic molded bodies 41 to 43 are dried and It does not matter at which stage degreasing and calcining is performed. For example, at least one of the first to third ceramic molded bodies 41 to 43 may be laminated after being dried, or at least one of the first to third ceramic molded bodies 41 to 43 may be dried and degreased. After performing, you may laminate | stack, after laminating | drying, degreasing, and calcining one or two of the 1st-3rd ceramic molded bodies 41-43, you may laminate | stack. In any case, since the laminate includes those that have not completed at least one step of drying, degreasing, and calcination, it is necessary to perform a process that has not been completed on the laminate. Or you may laminate | stack, after drying, degreasing, and calcining all three 1st-3rd ceramic molded bodies 41-43 separately. In that case, drying, degreasing, and calcination after lamination are unnecessary.

  In the embodiment described above, the electrostatic electrode precursor 24 is embedded in the first ceramic molded body 41, and the heater electrode precursor 26 is embedded in the third ceramic molded body 43. Instead, as shown in FIG. 2 The electrostatic electrode precursor 124 may be embedded on the upper surface of the ceramic molded body 142, and the heater electrode precursor 126 may be embedded on the lower surface, and the first and third ceramic molded bodies 141 and 143 may not be formed with an electrode precursor (see FIG. 3 (a) to (g)). Specifically, the first and third ceramic molded bodies 141 and 143 are produced by the gel cast method without attaching the electrode precursor to the first and third molding dies 31 and 33 (FIGS. 3A and 3B). ), (F), (g)). In addition, the electrostatic electrode precursor 124 is detachably attached to the inner surface of the upper die of the second mold 32 and the heater electrode precursor 126 is detachably attached to the inner surface of the lower die 32. A ceramic molded body 142 is produced (see FIGS. 3C to 3E). Thereby, the 2nd ceramic molded object 142 with which the electrostatic electrode precursor 124 and the heater electrode precursor 126 were embedded, ie, the ceramic molded object 142X with an embedded electrode, is obtained. Then, a laminated molded body 140 is produced using these ceramic molded bodies 141, 142X, and 143, and this is dried, degreased and calcined to obtain a laminated calcined body 150, and then subjected to hot press firing and electrostatic chuck. 110 is manufactured (see FIGS. 3I to 3K). This is the same as FIGS. 2 (i) to 2 (k). Even if it does in this way, it can suppress that the end surface of the electrostatic electrode 114 or the heater electrode 116 deform | transforms similarly to embodiment mentioned above.

  The electrostatic chuck 10 may be manufactured as shown in FIG. 4 using the ceramic molded bodies 41X and 43X with embedded electrodes manufactured in the above-described embodiment. That is, first, these ceramic molded bodies 41X and 43X and an integrated molding die 34 whose inner space has a size that takes into account the shrinkage rate with respect to the electrostatic chuck 10 are prepared (see FIG. 4A). Then, a surface opposite to the electrode forming surface of the ceramic molded body 41X with embedded electrode is attached to the inner surface of the upper mold of the integration mold 34, and embedded in the inner surface of the lower mold of the integration mold 34. The surface opposite to the electrode forming surface of the ceramic molded body 43X with electrodes is attached (see FIG. 4B). Next, a ceramic slurry containing ceramic powder, a solvent, a dispersant, and a gelling agent is poured into the integration mold 34, and the gelling agent is chemically reacted to gel the ceramic slurry. Thereby, since the 2nd ceramic molded object 42 is formed, the laminated molded object 40 is completed. Thereafter, the laminated molded body 40 is released from the integration mold 34 (see FIG. 4C). The laminated molded body 40 is dried, degreased, and calcined further to obtain a laminated calcined body 50 (see FIG. 4D). The laminated calcined body 50 is hot-press fired to obtain an electrostatic chuck. 10 is obtained (see FIG. 4E). Even if it does in this way, it can suppress that the end surface of the electrostatic electrode 14 or the heater electrode 16 deform | transforms similarly to embodiment mentioned above.

  The electrostatic chuck 110 may be manufactured as shown in FIG. 5 by using the ceramic molded body 142X with embedded electrodes shown in FIG. That is, first, a ceramic molded body 142X with embedded electrodes and an integration mold 36 whose inner space is sized with respect to the electrostatic chuck 110 in consideration of the contraction rate are prepared (see FIG. 5A). Then, a ceramic molded body 142X with embedded electrodes is attached to the center of the internal space of the integration mold 36 (see FIG. 5B). The integration mold 36 includes two injection ports 36a and 36b. The injection port 36a can inject ceramic slurry into the space surrounded by the upper mold of the integration mold 36 and the ceramic molded body 142X with embedded electrode, and the injection port 36b is the lower mold of the integration mold 36. And ceramic slurry can be injected into a space surrounded by the ceramic molded body 142X with embedded electrodes. Next, a ceramic slurry containing ceramic powder, a solvent, a dispersant, and a gelling agent is poured from the inlets 36a and 36b into the integrating mold 36, and the gelling agent is chemically reacted to gel the ceramic slurry. Thereby, since the 1st and 3rd ceramic molded objects 141 and 143 are formed, the laminated molded object 140 is completed. Thereafter, the laminated molded body 140 is released from the integration mold 36 (see FIG. 5C). The laminated molded body 140 is dried, degreased, and further calcined to obtain a laminated calcined body 150 (see FIG. 5D). The laminated calcined body 150 is hot-press fired to obtain an electrostatic chuck. 110 is obtained (see FIG. 5E). Even if it does in this way, it can suppress that the end surface of the electrostatic electrode 114 or the heater electrode 116 deform | transforms similarly to embodiment mentioned above.

(2) Embodiment Regarding Manufacturing Method of Second Electrostatic Chuck A manufacturing method of the electrostatic chuck 10 will be described below with reference to FIG. FIG. 6 is a manufacturing process diagram showing an example of a manufacturing method of the second electrostatic chuck. Since this manufacturing method is the same as the manufacturing method of the first electrostatic chuck except that the manufacturing methods of the first ceramic molded body 41 and the third ceramic molded body 43 are different, the following description will focus on different procedures.

(2-1) Production of First Ceramic Molded Body 41 First, a first mold 131 is prepared (see FIG. 6A). The first mold 131 has an internal space having a size that takes into account the shrinkage rate with respect to the first ceramic calcined body 51, but has the same shape as the electrostatic electrode precursor 24 on the inner surface of the lower mold. The convex portion 131a is provided so as not to be detachable. A ceramic slurry containing ceramic powder, a solvent, a dispersing agent and a gelling agent is poured into the internal space of the first mold 131, and the gelling agent is chemically reacted to gel the ceramic slurry and then released. Thereby, the 1st ceramic molded object 41 provided with the recessed part 41a corresponding to the electrostatic electrode precursor 24 is obtained (refer FIG.6 (b)). Next, the electrostatic electrode precursor 24 is formed by screen printing using the electrode paste in the recess 41a. Thereby, the 1st ceramic molded object 41 with which the electrostatic electrode precursor 24 was embedded, ie, the ceramic molded object 41X with an embedded electrode, is obtained (refer FIG.6 (c)).

(2-2) Production of Second Ceramic Molded Body 42 The procedures of FIGS. 6D and 6E are the same as the method for manufacturing the first electrostatic chuck described with reference to FIGS. 2D and 2E. Therefore, the description is omitted.

(2-3) Production of Third Ceramic Molded Body 43 First, a third molding die 133 is prepared (see FIG. 6F). The third mold 133 has an internal space (an internal space slightly larger than that of the third ceramic calcined body 53) having a size in consideration of the contraction rate with respect to the third ceramic calcined body 53. A convex portion 133a having the same shape as the heater electrode precursor 26 is provided on the inner surface of the upper die in a non-detachable manner. A ceramic slurry containing ceramic powder, a solvent, a dispersant, and a gelling agent is poured into the internal space of the third mold 133, and the gelling agent is chemically reacted to gel the ceramic slurry and then released. Thereby, the 3rd ceramic molded object 43 provided with the recessed part 43a corresponding to the heater electrode precursor 26 is obtained (refer FIG.6 (g)). Next, the heater electrode precursor 26 is formed by screen printing using the electrode paste in the recess 43a. Thus, a third ceramic molded body 43 in which the heater electrode precursor 26 is embedded, that is, a ceramic molded body 43X with embedded electrodes is obtained (see FIG. 6 (h)).

(2-4) Production of Electrostatic Chuck 10 The procedures of FIGS. 6 (i) to (k) are the same as the first electrostatic chuck manufacturing method described with reference to FIGS. 2 (i) to (k). Therefore, the description is omitted.

(2-5) Effect According to the manufacturing method of the electrostatic chuck 10 described in detail above, it is possible to suppress deformation of the end surfaces of the electrostatic electrode 14 and the heater electrode 16 having a predetermined shape. Specifically, a first ceramic molded body 41 having a recess 41 a is produced, and the electrostatic electrode precursor 24 is formed in the recess 41 a of the first ceramic molded body 41. At this time, since the first ceramic molded body 41 is made by gelling ceramic slurry in which ceramic powder is dispersed, it is possible to prevent the electrostatic electrode or its precursor from being scraped off, and the electrode It is considered that the ceramic powder is uniformly and uniformly filled at the interface, and the deformation of the electrode can be suppressed during hot press firing. Moreover, since the electrostatic electrode precursor 24 does not protrude outside, there is no possibility that the end portion of the electrostatic electrode precursor 24 is rubbed with other members and deformed. As a result of the above, it is considered that the end face of the electrostatic electrode 14 having a predetermined shape could be suppressed from being deformed. This also applies to the heater electrode precursor 26.

(2-6) Other Embodiments In the above-described embodiment, the first to third ceramic molded bodies 41 to 43 are laminated as they are without drying, degreasing, and calcining to form a laminated molded body 40, and this laminated molding is performed. The body 40 is dried, degreased, and calcined to obtain a laminated calcined body 50. If the laminated calcined body 50 is finally obtained, the first to third ceramic molded bodies 41 to 43 are dried and It does not matter at which stage degreasing and calcining is performed. For example, at least one of the first to third ceramic molded bodies 41 to 43 may be laminated after being dried, or at least one of the first to third ceramic molded bodies 41 to 43 may be dried and degreased. After performing, you may laminate | stack, after laminating | drying, degreasing, and calcining one or two of the 1st-3rd ceramic molded bodies 41-43, you may laminate | stack. In any case, since the laminate includes those that have not completed at least one step of drying, degreasing, and calcination, it is necessary to perform a process that has not been completed on the laminate. Or you may laminate | stack, after drying, degreasing, and calcining all three 1st-3rd ceramic molded bodies 41-43 separately. In that case, drying, degreasing, and calcination after lamination are unnecessary.

  In the embodiment described above, the electrostatic electrode precursor 24 is formed in the concave portion 41a of the first ceramic molded body 41, and the heater electrode precursor 26 is formed in the concave portion 43a of the third ceramic molded body 43. As shown in FIG. 7, the electrostatic electrode precursor 124 is formed in the concave portion 142a on the upper surface of the second ceramic molded body 142, and the heater electrode precursor 126 is formed in the concave portion 142b on the lower surface, and the first and third ceramic molded bodies 141, 143 may not form an electrode precursor. Specifically, the first ceramic molded body 141 is manufactured by the steps shown in FIGS. 3A and 3B (see FIG. 7A), and the steps shown in FIGS. 3F and 3G are performed. Thus, a third ceramic molded body 143 is produced (see FIG. 7E). Further, as the second molding die 132, a convex portion 132a having the same shape as that of the electrostatic electrode precursor 124 is formed on the inner surface of the upper die in a non-detachable manner, and the convex shape having the same shape as that of the heater electrode precursor 126 is provided on the inner surface of the lower die. The part 132b is formed so as not to be detachable (see FIG. 7B). A second ceramic molded body 142 having concave portions 142a and 142b corresponding to the convex portions 132a and 132b is produced by gel casting using the second molding die 132 (see FIG. 7C). Then, the electrode paste is screen-printed in the recesses 142a and 142b to obtain the second ceramic molded body 142 in which the electrostatic electrode precursor 124 and the heater electrode precursor 126 are embedded, that is, the ceramic molded body 142X with embedded electrodes. (Refer FIG.7 (d)). Thereafter, a multilayer molded body 140 is manufactured using these ceramic molded bodies 141, 142 X, and 143, and this is calcined to obtain a multilayer calcined body 150, and then hot press firing to produce the electrostatic chuck 110. (Refer to Drawing 7 (f)-(h)). This is the same as in FIGS. 2 (i) to (k). Even if it does in this way, it can suppress that the end surface of the electrostatic electrode 114 or the heater electrode 116 deform | transforms similarly to embodiment mentioned above.

(3) Embodiment Regarding Method for Manufacturing Third Electrostatic Chuck A method for manufacturing the electrostatic chuck 110 will be described below with reference to FIG. FIG. 8 is a manufacturing process diagram showing an example of a third method for manufacturing an electrostatic chuck.

(3-1) Production of the first and third ceramic molded bodies 141 and 143 First, as shown in FIGS. 8A and 8B, the electrostatic electrode precursor 124 convex to the first ceramic molded body 141. The ceramic molded body 141 </ b> Y with the convex electrode formed with the above and the ceramic molded body 143 </ b> Y with the convex electrode in which the convex heater electrode precursor 126 is formed on the third ceramic molded body 143 are manufactured. In the former, the first ceramic molded body 141 is manufactured through the steps shown in FIGS. 3A and 3B described above, and then the electrode paste is screen printed on the lower surface thereof to form the electrostatic electrode precursor 124. , Make. In the latter, the third ceramic molded body 143 is manufactured through the steps of FIGS. 3 (f) and 3 (g) described above, and then the electrode paste is screen printed on the upper surface to form the heater electrode precursor 126. Make it.

(3-2) Production of Laminated Molded Body 140 An integrated molding die 38 whose inner space has a size with respect to the electrostatic chuck 110 in consideration of the contraction rate is prepared (see FIG. 8C). Then, a surface opposite to the electrode forming surface of the ceramic molded body 141Y with convex electrodes is attached to the inner surface of the upper mold of the integrating mold 38, and convex electrodes are mounted on the inner surface of the lower mold of the integrating mold 38. A surface opposite to the electrode forming surface of the ceramic molded body 143Y is attached (see FIG. 8D). Next, a ceramic slurry containing ceramic powder, a solvent, a dispersing agent and a gelling agent is poured into the integration mold 38, and the gelling agent is chemically reacted to gel the ceramic slurry. Thereby, since the 2nd ceramic molded object 142 is formed, the laminated molded object 140 is completed. Thereafter, the laminated molded body 140 is released from the integration mold 38 (see FIG. 8E).

(3-3) Production of electrostatic chuck 110 The laminated molded body 140 is dried, degreased, and further calcined to obtain a laminated calcined body 150 (see FIG. 8F). And the electrostatic chuck 110 is obtained by carrying out hot press baking of this laminated calcined body 150 (refer FIG.8 (g)).

(3-4) Effect According to the manufacturing method of the electrostatic chuck 110 described above, it is possible to suppress deformation of the end surfaces of the electrostatic electrode 114 and the heater electrode 116 having a predetermined shape. Specifically, after the ceramic molded bodies 141Y and 143Y with convex electrodes are detachably attached to the inner surface of the integration mold 38, the ceramic slurry is poured into the integration mold 38 to be gelled, and the initial reaction slurry is Since the viscosity is low and the fluidity is high, it is possible to prevent the end surfaces of the electrostatic electrode 114 and the heater electrode 116 from being scraped, and the ceramic powder is uniformly and uniformly filled in the electrode interface, and the electrode is deformed during hot press firing. Can be suppressed.

(3-5) Other Embodiments In the above-described embodiments, the first and third ceramic molded bodies 141 and 143 are set in the integration mold 38 without drying, degreasing, and calcining. It does not matter at which stage the third ceramic molded bodies 141 and 143 are dried, degreased and calcined. For example, at least one of the first and third ceramic molded bodies 141 and 143 may be set in the integration mold 38 after drying only, or may be set in the integration mold 38 after drying and degreasing. It may be set, or after drying, degreasing and calcination, it may be set in the integration mold 38. In any case, since the laminated body taken out from the integration mold 38 includes the second ceramic molded body 142 that has not been dried, degreased, and calcined, the laminated body is dried, degreased, and temporarily removed. It is necessary to bake. In addition, when performing any of drying, degreasing, and calcination in advance, the timing may be before or after printing the electrode paste.

  In the embodiment described above, the step of detachably attaching the ceramic molded body with convex electrodes 141Y to the inner surface of the upper mold 38 and the ceramic molded body with convex electrodes 143Y to the inner surface of the lower mold was included. Instead, as shown in FIG. 9, a step of detachably attaching the ceramic molded body 42 </ b> Y with the convex electrode may be included in the center of the internal space of the integration mold 36 (above). Specifically, the electrostatic paste 24 is printed on the upper surface of the second ceramic molded body 42 produced in the same manner as in FIGS. 2D and 2E, and the heater electrode precursor 26 is printed on the lower surface with an electrode paste. Thus, the ceramic molded body 42Y with convex electrodes is formed (see FIG. 9A), and this is attached to the center of the internal space of the integration mold 36 (see FIG. 9B). The injection port 36a can inject ceramic slurry into a space surrounded by the upper mold of the integration mold 36 and the ceramic molded body 42Y with convex electrodes, and the injection port 36b has a lower mold of the integration mold 36. Ceramic slurry can be injected into the space surrounded by the ceramic molded body 42 </ b> Y with convex electrodes. Next, since the first and third ceramic molded bodies 41 and 43 are formed by injecting the ceramic slurry from the inlets 36a and 36b and causing it to gel, the laminated molded body 40 is completed. Thereafter, the laminated molded body 40 is released from the integration mold 36 (see FIG. 9C). The laminated molded body 40 is dried, degreased, and calcined to obtain a laminated calcined body 50 (see FIG. 9D). The laminated calcined body 50 is subjected to hot press firing, whereby the electrostatic chuck 10 is obtained. (See FIG. 8E). Even if it does in this way, it can suppress that the end surface of the electrostatic electrode 14 or the heater electrode 16 deform | transforms similarly to embodiment mentioned above.

  The above 6. In (1) to (3), the method of manufacturing the electrostatic chuck incorporating the heater electrode has been described. However, if the heater electrode and the third ceramic molded body are omitted, the electrostatic chuck does not include the heater electrode. Can be manufactured.

[Example 1]
An electrostatic chuck was produced according to FIG. First, a first mold having a disk-shaped internal space having a diameter of 355 mm and a height of 3.0 mm, a second mold having a disk-shaped internal space having a diameter of 355 mm and a height of 6.0 mm, a diameter of 355 mm, and a high A third mold having a disk-shaped internal space with a thickness of 3.0 mm was prepared.

  On the other hand, WC powder (average particle size 1.5 μm) and alumina powder (average particle size 0.5 μm) were made so that the alumina content was 20% by weight, 5 parts by weight of polyvinyl butyral as a binder, and 20% of terpineol as a solvent. An electrode paste was prepared by adding parts and mixing. An electrode paste was screen printed on the inner surface of the lower mold of the first mold so as to have a diameter of 290 mm and a height of 10 μm to obtain an electrostatic electrode precursor. Further, the electrode paste was screen-printed on the inner surface of the upper mold of the third molding die so as to have a one-stroke writing shape with a width of 8 mm and a height of 50 μm to obtain a heater electrode precursor.

  100 parts by weight of alumina powder (average particle size 0.5 μm, purity 99.7%), 0.04 parts by weight of magnesia, 3 parts by weight of a polycarboxylic acid copolymer as a dispersant, and 20 parts by weight of a polybasic acid ester as a solvent Were weighed and mixed with a ball mill (Trommel) for 14 hours to obtain a slurry precursor. With respect to this slurry precursor, gelling agent, that is, 3.3 parts by weight of 4,4′-diphenylmethane diisocyanate as isocyanates, 0.3 parts by weight of ethylene glycol as polyols, and 6-dimethylamino-1-hexanol as catalyst 0.1 part by weight was added and mixed with a self-revolving stirrer for 12 minutes to obtain a ceramic slurry. The obtained ceramic slurry was poured into a first mold on which an electrostatic electrode precursor was printed, a second mold on which printing was not performed, and a third mold on which a heater electrode precursor was printed. Then, by leaving it at 22 ° C. for 2 hours, the gelling agent was chemically reacted in each mold to gel the ceramic slurry, and then released. As a result, a ceramic molded body with an electrostatic electrode in which an electrostatic electrode precursor is embedded in the first ceramic molded body, a second ceramic molded body without an electrode, and a heater electrode precursor on the third ceramic molded body. An embedded ceramic molded body with a heater electrode was obtained.

  And these are laminated | stacked so that an electrostatic electrode precursor may be inserted | pinched between the 1st and 2nd ceramic molded object, and a heater electrode precursor may be inserted | pinched between the 2nd and 3rd ceramic molded object, and it was set as the laminated molded object. . The laminated compact was dried at 100 ° C. for 10 hours, degreased at a maximum temperature of 500 ° C. for 10 hours, and further calcined at a maximum temperature of 820 ° C. for 1 hour in an argon atmosphere to obtain a laminated calcined body. .

This laminated calcined body was hot-press fired to obtain an electrostatic chuck incorporating an electrostatic electrode and a heater electrode. Hot press firing was carried out by holding at a pressure of 100 kgf / cm ² and a maximum temperature of 1600 ° C. for 2 hours in a nitrogen atmosphere. The obtained electrostatic chuck had a carbon content of 0.1% by weight or less and a relative density of 98% or more. Moreover, the end surface of the electrostatic electrode was a flat vertical surface (angle θ in FIG. 1 was 180 °) when viewed in a longitudinal section, and no deformation was observed.

[Example 2]
An electrostatic chuck was produced according to FIG. First, the same 1st-3rd shaping | molding die similar to Example 1 was prepared. And the electrode paste was screen-printed on the inner surface of the upper mold of the second mold, and the same electrostatic electrode precursor as in Example 1 was obtained. In addition, an electrode paste was screen-printed on the lower mold of the second mold to obtain a heater electrode precursor similar to that in Example 1.

  Subsequently, the same ceramic slurry as in Example 1, a first mold not printed, a second mold printed with an electrostatic electrode precursor and a heater electrode precursor, a third mold not printed The ceramic slurry was gelled and then released. Thus, the first ceramic molded body without electrodes, the ceramic molded body with electrodes in which the electrostatic electrode precursor and the heater electrode precursor are embedded in the second ceramic molded body, and the third ceramic without electrodes. A molded body was obtained.

  These were laminated so that the electrostatic electrode precursor was sandwiched between the first and second ceramic compacts, and the heater electrode precursor was sandwiched between the second and third ceramic compacts to form a multilayer compact. This laminated molded body was dried, degreased and calcined in the same manner as in Example 1. This laminated calcined body was hot-press fired under the same conditions as in Example 1 to obtain an electrostatic chuck incorporating an electrostatic electrode and a heater electrode. The obtained electrostatic chuck had a carbon content of 0.1% by weight or less and a relative density of 98% or more. Further, the end face of the electrostatic electrode was a bulged surface having an angle θ of 172 ° in FIG. 1 when viewed in a longitudinal section, and almost no deformation was observed.

[Example 3]
An electrostatic chuck was produced according to the third method for producing an electrostatic chuck shown in FIG. First, first and third molds similar to those in Example 1 were prepared, and an integration mold having an internal space with a size corresponding to the laminated molded body was prepared. And the ceramic slurry similar to Example 1 was poured into the 1st and 3rd shaping | molding die, and it released after making the ceramic slurry gelatinize. This obtained the 1st and 3rd ceramic molded object. Subsequently, an electrode paste was screen printed on the lower surface of the first ceramic molded body to obtain a first ceramic molded body with a convex electrostatic electrode precursor. Moreover, the electrode paste was screen-printed on the upper surface of the third ceramic molded body to obtain a third ceramic molded body with a convex heater electrode precursor.

  Next, the surface opposite to the electrode forming surface of the first ceramic molded body with the convex electrostatic electrode precursor attached was attached to the inner surface of the upper mold of the integrating mold. At the same time, the surface opposite to the electrode forming surface of the third ceramic molded body with the convex heater electrode precursor attached to the inner surface of the lower mold was attached. And the ceramic slurry similar to Example 1 was poured into the shaping | molding die for integration, the gelling agent was made to react chemically, and the ceramic slurry was gelatinized. As a result, a second ceramic molded body was formed. As a result, the electrostatic electrode precursor was sandwiched between the first and second ceramic molded bodies, and the heater electrode precursor was sandwiched between the second and third ceramic molded bodies. A laminated composite of structure was completed. Thereafter, the laminated composite was released from the integration mold.

  This laminated composite was dried, degreased and calcined in the same manner as in Example 1 to obtain a laminated calcined body. This laminated calcined body was hot-press fired under the same conditions as in Example 1 to obtain an electrostatic chuck incorporating an electrostatic electrode and a heater electrode. The obtained electrostatic chuck had a carbon content of 0.1% by weight or less and a relative density of 98% or more. Further, the end surface of the electrostatic electrode was a bulging surface having an angle θ of 176 ° in FIG. 1 when viewed in a longitudinal section, and almost no deformation was observed.

[Example 4]
In Example 3, the first and third ceramic molded bodies before printing the electrode paste were dried at 100 ° C. for 10 hours, degreased at a maximum temperature of 500 ° C. for 10 hours, and further at a maximum temperature of 820 ° C. in an argon atmosphere. An electrostatic chuck was produced in the same manner as in Example 3 except that the first and third ceramic calcined bodies were obtained by calcining for 1 hour and then electrode paste was printed on each. The obtained electrostatic chuck had a carbon content of 0.1% by weight or less and a relative density of 98% or more. Further, the end surface of the electrostatic electrode was a bulging surface having an angle θ of 176 ° in FIG. 1 when viewed in a longitudinal section, and almost no deformation was observed.

[Example 5]
An electrostatic chuck was produced according to the third method for producing an electrostatic chuck shown in FIG. First, while preparing the 2nd shaping | molding die similar to Example 1, the shaping | molding die for integration which has the space corresponding to the laminated molded object was prepared. And the ceramic slurry similar to Example 1 was poured into the 2nd shaping | molding die, and it released after making the ceramic slurry gel. This obtained the 2nd ceramic molded object. Then, the electrode paste of Example 1 is screen-printed on the upper surface and the lower surface of the second ceramic molded body, respectively, and the second ceramic molded body with the convex electrostatic electrode precursor and the convex heater electrode precursor is attached. Got.

  Next, the 2nd ceramic molded object was arrange | positioned in the center of internal space in the shaping | molding die for integration. And the ceramic slurry similar to Example 1 was poured into the empty space of the internal space of the integration mold, and the gelling agent was chemically reacted to gel the ceramic slurry. As a result, the first and third ceramic molded bodies are formed. As a result, the electrostatic electrode precursor is sandwiched between the first and second ceramic molded bodies, and the heater electrode precursor becomes the second and third ceramic molded bodies. The laminated composite with the sandwiched structure was completed. Thereafter, the laminated composite was released from the integration mold.

  This laminated composite was dried, degreased and calcined in the same manner as in Example 1 to obtain a laminated calcined body. This laminated calcined body was hot-press fired under the same conditions as in Example 1 to obtain an electrostatic chuck incorporating an electrostatic electrode and a heater electrode. The obtained electrostatic chuck had a carbon content of 0.1% by weight or less and a relative density of 98% or more. Further, the end surface of the electrostatic electrode was a bulging surface having an angle θ of 174 ° in FIG. 1 when viewed in a longitudinal section, and almost no deformation was observed.

[Example 6]
In Example 5, the second ceramic molded body before printing the electrode paste was dried at 100 ° C. for 10 hours, degreased at a maximum temperature of 500 ° C. for 10 hours, and further at an maximum temperature of 820 ° C. for 1 hour in an argon atmosphere. An electrostatic chuck was produced in the same manner as in Example 5 except that the second ceramic calcined body was obtained by calcining and electrode paste was printed on both sides. The obtained electrostatic chuck had a carbon content of 0.1% by weight or less and a relative density of 98% or more. Further, the end surface of the electrostatic electrode was a bulging surface having an angle θ of 176 ° in FIG. 1 when viewed in a longitudinal section, and almost no deformation was observed.

[Comparative Example 1]
First, an upper alumina sintered body serving as a dielectric layer and a lower alumina sintered body serving as a lower layer were prepared. The upper alumina sintered body was produced as follows. That is, alumina powder with a purity of 99.7% and MgO raw material powder as a sintering aid were weighed so that the MgO content was 0.04 wt%. To these raw material powders, polyvinyl alcohol (PVA) as a binder, water and a dispersant were added and mixed for 16 hours with a trommel to prepare a slurry. This slurry was spray-dried using a spray dryer, and then held at 500 ° C. for 5 hours to remove the binder, and alumina granulated granules having an average of about 80 μm were prepared. This alumina granulated granule was filled in a mold and press-molded at a pressure of 200 kg / cm ² . Subsequently, the compact was set in a carbon sheath and fired using a hot press firing method. Firing is performed under a pressure of 100 kg / cm ² and in a nitrogen pressure atmosphere (150 kPa), heated at 300 ° C./h, held at 1600 ° C. for 2 hours, and sintered in a portion corresponding to the dielectric layer. Got the body. This alumina sintered body was ground to produce a disk-shaped upper alumina sintered body having a diameter of 300 mm and a thickness of 6 mm. One surface at this time was finished so as to be a smooth surface having a surface roughness Ra of 0.8 μm or less. The lower alumina sintered body was also produced according to this. Subsequently, an electrode paste similar to that of Example 1 was screen-printed on the upper alumina sintered body to obtain an electrostatic electrode precursor. Also, a heater electrode precursor was obtained by screen printing on the lower alumina sintered body.

Subsequently, when the upper alumina sintered body on which the electrostatic electrode precursor is formed is accommodated in the mold so that the electrostatic electrode precursor is on the upper side, the upper alumina sintered body is produced on the upper alumina sintered body. A predetermined amount of the granulated alumina granule was placed, and a lower alumina sintered body on which the heater electrode precursor was formed was placed thereon so that the heater electrode precursor was on the bottom. In this state, the laminate was molded by pressurizing at a pressure of 200 kgf / cm ² in the vertical compression direction. This laminate has a structure in which the electrostatic electrode precursor is sandwiched between the upper alumina sintered body and the alumina granulated granule layer, and the heater electrode precursor is sandwiched between the alumina granulated granule layer and the lower alumina sintered body. is there. The laminate was dried, degreased and calcined in the same manner as in Example 1 and then hot-press fired to obtain an electrostatic chuck incorporating an electrostatic electrode and a heater electrode. Hot press firing was performed under the same conditions as in Example 1.

  The obtained electrostatic chuck had a carbon content of 0.1% by weight or less and a relative density of 98% or more. Further, the end face of the electrostatic electrode had a pointed shape (angle θ in FIG. 1 was 30 °) when viewed in a longitudinal section.

[Comparative Example 2]
First, a middle alumina sintered body serving as an intermediate layer was produced according to the upper alumina sintered body of Comparative Example 1. Subsequently, the same electrode paste as in Example 1 was screen-printed on the upper and lower surfaces of the central alumina sintered body to obtain an electrostatic electrode precursor and a heater electrode precursor, respectively.

Subsequently, a predetermined amount of the alumina granulated granules prepared when the upper alumina sintered body was produced was laid in the mold, and the electrostatic electrode precursor faced downward, and the heater electrode precursor The middle alumina sintered body was placed so that the upper side faced upward, and a predetermined amount of alumina granulated granules was placed thereon. In this state, the laminate was molded by pressurizing at a pressure of 200 kgf / cm ² in the vertical compression direction. In this laminate, the electrostatic electrode precursor is sandwiched between one alumina granulated granule layer and the middle alumina sintered body, and the heater electrode precursor is sandwiched between the middle alumina granulated body and the other alumina granulated layer. Structure. The laminate was dried, degreased and calcined in the same manner as in Example 1 and then hot-press fired to obtain an electrostatic chuck incorporating an electrostatic electrode and a heater electrode. Hot press firing was performed under the same conditions as in Example 1.

  The obtained electrostatic chuck had a carbon content of 0.1% by weight or less and a relative density of 98% or more. Further, the end face of the electrostatic electrode had a pointed shape (angle θ in FIG. 1 was 20 °) when viewed in a longitudinal section.

10 electrostatic chuck, 10a wafer mounting surface, 14 electrostatic electrode, 14a end surface, 14b upper corner, 14c bulging tip, 14d lower corner, 16 heater electrode, 24 electrostatic electrode precursor, 26 heater electrode precursor, 31 1 Mold, 32 2nd Mold, 33 3rd Mold, 34 Integration Mold, 36 Integration Mold, 36a, 36b Inlet, 38 Integration Mold, 40 Laminated Mold, 41 First Ceramic Mold Body, 41a concave portion, 41X ceramic molded body with embedded electrode, 42 second ceramic molded body, 42Y ceramic molded body with convex electrode, 43 third ceramic molded body, 43a concave portion, 43X ceramic molded body with embedded electrode, 50 layers Calcined body, 51 first ceramic calcined body, 52 second ceramic calcined body, 53 third ceramic calcined body, 110 electrostatic chuck , 114 electrostatic electrode, 116 heater electrode, 124 electrostatic electrode precursor, 126 heater electrode precursor, 131 first molding die, 131a convex portion, 132 second molding die, 132a, 132b convex portion, 133 third molding Mold, 133a convex portion, 140 laminated molded body, 141 first ceramic molded body, 141Y ceramic molded body with convex electrode, 142 second ceramic molded body, 142a, 142b concave portion, 142X ceramic molded body with embedded electrode, 142Y convex electrode Ceramic molded body with attachment, 143 3rd ceramic molded body, 143Y Ceramic molded body with convex electrode, 150 laminated calcined body.

Claims (2)

An electrostatic chuck in which an electrostatic electrode is built in a ceramic fired body,
When the end face of the electrostatic electrode is viewed in a longitudinal section, the entire end face is a bulging surface, and an angle θ connecting the upper corner, the bulging tip, and the lower corner of the bulging surface is 160 ≦ θ <180 °. is there,
Electrostatic chuck. The electrostatic chuck according to claim 1,
The ceramic fired body includes a heater electrode incorporated separately from the electrostatic electrode,
When the end face of the heater electrode is viewed in a longitudinal section, the entire end face is a bulging surface, and an angle θ connecting the upper corner, the bulging tip and the lower corner of the bulging surface is 160 ≦ θ <180 °. ,
Electrostatic chuck.

Images