KR20230120209A - Method for manufacturing ceramic heater, ceramic heater manufactured therefrom, and semiconductor holding device comprising the same - Google Patents

Abstract

A method of manufacturing a ceramic heater plate is provided. A ceramic heater plate according to an embodiment of the present invention includes the steps of (1) forming a pattern portion by intaglioing a groove having a predetermined width and depth extending along the surface of a first ceramic layer containing silicon; (2) Placing a resistance heating element and a filler containing silicon filling the remaining space of the groove accommodating the resistance heating element in the groove, (3) a ceramic in which a second ceramic layer containing silicon is temporarily bonded on one surface of the first ceramic layer It is implemented by including preparing a molded body and (4) preparing a silicon nitride (Si ₃ N ₄ ) ceramic sintered body by nitriding and sintering the ceramic molded body. According to this, manufacturing time and man-hours can be reduced, making it suitable for mass production of ceramic heater plates. In addition, it can be widely used in semiconductor holding devices used in harsh semiconductor processes as it exhibits excellent heat dissipation performance and excellent plasma resistance, chemical resistance and thermal shock resistance.

Description

Method for manufacturing a ceramic heater plate, a ceramic heater plate manufactured through the same, and a semiconductor holding device including the same

The present invention relates to a method for manufacturing a ceramic heater plate, a ceramic heater plate manufactured through the method, and a semiconductor holding device including the same.

In general, a semiconductor device or display device is manufactured by sequentially stacking a plurality of thin film layers including a dielectric layer and a metal layer on a glass substrate, a flexible substrate, or a semiconductor wafer substrate and then patterning them. These thin film layers are sequentially deposited on a substrate through a chemical vapor deposition (CVD) process or a physical vapor deposition (PVD) process. The CVD process includes a Low Pressure CVD (LPCVD) process, a Plasma Enhanced CVD (PECVD) process, a Metal Organic CVD (MOCVD) process, and the like.

A heater for supporting a glass substrate, a flexible substrate, a semiconductor wafer substrate, and the like and applying a predetermined heat is disposed in such a CVD device and a PVD device. The heater is also used for substrate heating in an etching process of thin film layers formed on a support substrate and a firing process of photoresist. As heaters installed in the CVD and PVD devices, ceramic heaters are widely used in accordance with the requirements for accurate temperature control, fine wiring of semiconductor devices, and precise heat treatment of semiconductor wafer substrates.

In recent years, due to miniaturization and high integration of semiconductor processes and harsh deposition processes, wafer heating and cooling are repeated, deposition processes are performed at higher temperatures, and deposition times are also increasing. Ceramics for the existing PVD and CVD processes As AlN ceramics are mainly used in heaters, they cannot withstand severe process conditions and breakage occurs frequently, so there is an increasing demand for high thermal shock resistance that is not easily destroyed by rapid temperature changes. In addition, due to the extended and severe deposition process, the demand for plasma resistance or chemical resistance is also increasing.

Republic of Korea Patent Publication No. 10-1998-0031739

The present invention has been devised in view of the above points, and has excellent heat dissipation characteristics while having chemical resistance, plasma resistance, and thermal shock resistance according to rapid temperature change even under harsh thermal and chemical environments, and these physical properties by position It is an object of the present invention to provide a method for manufacturing a ceramic heater plate capable of uniform expression, a ceramic heater plate manufactured through the method, and a semiconductor holding device including the same.

Another object of the present invention is to provide a method for manufacturing a ceramic heater plate capable of reducing manufacturing time and man-hours, a ceramic heater plate manufactured through the method, and a semiconductor holding device including the same.

The present invention has been devised in view of the above points, (1) forming a pattern portion by intaglioing a groove having a predetermined width and depth extending along the surface of one surface of the first ceramic layer containing silicon, ( 2) disposing a resistance heating element and a filler containing silicon filling the remaining space of the groove accommodating the resistance heating element in the groove, (3) temporarily bonding a second ceramic layer containing silicon on one surface of the first ceramic layer A method for manufacturing a ceramic heater plate is provided, which includes manufacturing a ceramic molded body made of the same, and (4) nitriding and sintering the ceramic molded body to manufacture a silicon nitride (Si ₃ N ₄ ) ceramic sintered body.

According to one embodiment of the present invention, in step (2), after disposing the resistance heating element in the groove, the remaining space of the groove in which the resistance heating element is disposed is filled with a filler containing silicon, or having a cross-sectional size accommodated in the groove A method of inserting the solidified filler containing silicon into the groove so that the resistance heating element is buried inside. The resistance heating element is provided inside to have a size accommodated in the groove, and the filler containing solidified silicon is inserted into the groove. can be performed

Step (3) includes 3-1) disposing an intermediate ceramic layer containing silicon on one surface of the first ceramic layer, 3-2) disposing an electrode on the intermediate ceramic layer, and 3-3) The method may include disposing a second ceramic layer on the electrode and then temporarily bonding the ceramic layers to each other.

Also, the grooves may be formed continuously or discontinuously.

In addition, in order to secure a space in which the ceramic filling composition surrounds the resistance heating element and prevent generation of voids inside the groove, the depth and width of the groove in the cross section perpendicular to the direction in which the groove extends is the height and width of the resistance heating element disposed in the groove. can be made larger.

In addition, each of the first ceramic layer and the second ceramic layer may be one or several ceramic green sheets stacked, and the thickness of the first ceramic layer may be 5 to 15 mm and the thickness of the second ceramic layer may be 3 to 5 mm. there is.

In addition, the first ceramic layer and the second ceramic layer may include a metal silicon powder, and a crystalline phase control powder including a rare earth element-containing compound and a magnesium-containing compound.

In addition, the rare earth element-containing compound may be yttrium oxide, and the magnesium-containing compound may be magnesium oxide, and 2 to 5 mol% of yttrium oxide and 4 to 8 mol% of magnesium oxide may be included based on the total number of moles of the ceramic composition. there is.

In addition, it further includes a strength enhancing powder containing at least one of iron oxide (Fe ₂ O ₃ ) and titanium oxide (TiO ₂ ), and 0.1 to 3 mol% of iron oxide and 1 to 5 titanium oxide based on the total number of moles of the ceramic composition. Mole % may be included.

In addition, the filler containing silicon may include 92 to 95% by weight of silicon nitride (Si ₃ N ₄ ) powder, 2 to 5% by weight of yttrium oxide, and 1 to 3% by weight of titanium oxide.

In addition, step (4) heat-treats the ceramic molded body at a first temperature of 1300 to 1500 ° C. while applying nitrogen gas at a predetermined pressure to silicon nitride (Si ₃ N ₄ ) A first heat treatment section and a first heat treatment section of 1700 to 1900 ° C. It may be performed through a heat treatment step including a second heat treatment section in which heat treatment is performed at 2 temperatures to sinter the ceramic molded body.

In addition, the heat treatment step may be heat treatment at a heating rate of 0.1 to 2 ° C. while applying nitrogen gas at a pressure of 0.1 to 0.2 MPa from 1000 ± 70 ° C to the first temperature.

In addition, nitrogen gas is applied at a pressure of 0.1 to 0.2 MPa in the first heat treatment section, and the first heat treatment section may be performed for 2 to 10 hours.

In addition, the pressure of the nitrogen gas applied from the 1000±70° C. to the first temperature may be lower than the pressure of the nitrogen gas applied in the first heat treatment section.

In addition, between the first heat treatment section and the second heat treatment section, the first contraction period in which the temperature is raised from the first temperature to 1700 ± 20 ° C. at a rate of 0.1 to 10.0 ° C. under a nitrogen gas pressure of 0.15 to 0.30 MPa and 1700 ± 20 ° C. It may further include a second contraction period in which the temperature is raised at a rate of 1 to 10 °C min under a nitrogen gas pressure of 0.80 to 0.98 MPa from to the second temperature.

In addition, the present invention includes a body that is a plate-shaped silicon nitride (Si ₃ N ₄ ) sintered body and a resistance heating element embedded in the body, wherein the body includes a first part surrounding at least a part of the resistance heating element and a second part that is the remaining part. , wherein the density of the first part and the density of the second part are different.

According to one embodiment of the present invention, the density of the first part may be smaller than the density of the second part.

In addition, the first part may be porous.

In addition, an electrode may be further included inside the body.

In addition, the present invention provides a semiconductor holding device including the ceramic heater plate according to the present invention.

According to the present invention, the method of manufacturing a ceramic heater plate can reduce manufacturing time and man-hours by performing a process of nitriding and sintering a molded body with silicon nitride (Si ₃ N ₄ ) in one step, and accordingly, the ceramic heater plate may be suitable for mass production. In addition, it is possible to minimize the temperature deviation of the surface of the ceramic heater plate according to the height difference of the resistance heating element buried inside, and cracks in the ceramic heater plate or shape deformation of the resistance heating element caused by the difference in thermal characteristics between the ceramic material and the resistance heating element can be minimized. And it is possible to minimize the temperature deviation caused by this. Furthermore, the realized ceramic heater plate exhibits the same or similar level of heat dissipation performance compared to the aluminum nitride ceramic sintered body that has been widely used in the past, but has excellent plasma resistance, chemical resistance and thermal shock resistance. device can be widely used.

1 and 2 are cross-sectional schematic views of ceramic molded bodies manufactured according to various embodiments of the present invention;
3 is a manufacturing process diagram of a ceramic molded body manufactured according to an embodiment of the present invention;
4 is a schematic cross-sectional view of a ceramic heater plate according to an embodiment of the present invention, and
6 is a temperature profile graph over time in a process for nitriding and sintering a ceramic molded body during a manufacturing process according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. This invention may be embodied in many different forms and is not limited to the embodiments set forth herein. In order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are added to the same or similar components throughout the specification.

Referring to FIGS. 1 to 5 , the ceramic heater plate 200 according to an embodiment of the present invention includes (1) a predetermined width extending along one side of a first ceramic layer 10 containing silicon. Step of forming the pattern portion 10a by intaglioing a groove having an over depth, (2) a resistance heating element 40 in the groove and a filling material 60 containing silicon filling the remaining space of the groove in which the resistance heating element 40 is accommodated ), (4) preparing a ceramic molded body (100, 100') in which a second ceramic layer (20) containing silicon is temporarily bonded on one surface of the first ceramic layer (10), and (4) It may be implemented by including preparing a silicon nitride (Si ₃ N ₄ ) ceramic sintered body 210 by nitriding and sintering the ceramic molded bodies 100 and 100'.

First, in step (1) according to the present invention, a groove having a predetermined width and depth extending along the surface is engraved on one surface of the first ceramic layer 10 containing silicon to form the pattern portion 10a. (Fig. 3 (a), (b)) is performed.

The first ceramic layer 10 is manufactured through a ceramic composition containing silicon, and the ceramic composition containing silicon is nitrided and sintered through a step (4) to be described later through a one-step process of silicon nitride (Si ₃ N ₄ ) can be designed to have a composition suitable for becoming a sintered body. To this end, the silicon-containing ceramic composition includes a crystal phase control powder including a metal silicon powder, a rare earth element-containing compound, and a magnesium-containing compound as a silicon-containing component.

The metal silicon powder is a ceramic composition subject, and may be used without limitation in the case of metal silicon powder used in the manufacture of a silicon nitride (Si ₃ N ₄ ) powder or a silicon nitride (Si ₃ N ₄ ) sintered body through a direct nitriding method. For example, the metal silicon powder may be polycrystalline metal silicon scrap or single crystal silicon wafer scrap. The polycrystalline metal silicon scrap may be a by-product of polycrystalline metal silicon used for semiconductor processing fixtures or solar panel manufacturing, and single-crystal silicon wafer scrap is also a by-product during silicon wafer manufacturing, so these scraps, which are by-products, are used as raw material powder. Through this, the manufacturing cost can be lowered.

In addition, the polycrystalline metal silicon scrap or single-crystal silicon wafer scrap may have a silicon purity of 99% or more, and the silicon nitride sintered body realized through this may be more advantageous in securing excellent thermal conductivity and mechanical strength.

In addition, the metal silicon powder may have a resistivity of 1 to 100 Ωcm, and through this, the present invention may be more advantageous than manufacturing a silicon nitride sintered body for a ceramic heater having desired physical properties.

Meanwhile, the metal silicon powder used as the raw material powder may preferably be pulverized polycrystalline metal silicon scrap or single crystal silicon wafer scrap into a predetermined size. At this time, in order to prevent contaminants such as metal impurities due to pulverization from being mixed into the raw material powder, the pulverization may use a dry pulverization method. can make it If contaminants are contained in the metal silicon powder, there is a concern of increasing manufacturing time and cost due to further washing processes such as acid washing to remove contaminants. At this time, the average particle diameter of the pulverized metal silicon powder may be 0.5 ~ 4㎛, more preferably 2 ~ 4㎛, if the average particle diameter is less than 0.5㎛, it may be difficult to implement through the dry grinding method, due to fine powder There is a concern that the mixing of contaminants may increase, and densification may be difficult during casting for manufacturing a molded body. In addition, if the average particle diameter of the metal silicon powder exceeds 4 μm, nitriding is not easy, so there is a concern that non-nitriding parts may exist, and densification of the final sintered body may be difficult.

In addition, the crystalline phase control powder is difficult to self-diffusion, which is the material of the silicon nitride (Si ₃ N ₄ ) sintered body material to be realized through step (4) described later, that is, it is difficult to self-diffusion and can be easily thermally decomposed at a high temperature, so that the sintering temperature Is limited, may be included to solve the difficulty of implementing a dense, uniformly nitrided sintered body, and to improve the physical properties of the silicon nitride sintered body by removing impurities such as oxygen. The crystalline phase control powder may be, for example, a rare earth element-containing compound, an alkaline earth metal oxide, and a combination thereof, and specifically, yttrium oxide (Y ₂ O ₃ ), gadolinium oxide (Gd ₂ O), and holmium oxide (Ho ₂ O ₃ ), erbium oxide (Er ₂ O ₃ ), yrtebium oxide (Yb ₂ O ₃ ), and at least one rare earth element-containing compound selected from the group consisting of dysprosium oxide (Dy ₂ O ₃ ), and magnesium oxide (MgO ), at least one alkaline earth metal oxide selected from the group consisting of calcium oxide, strontium oxide and barium oxide may be used in combination. However, the present invention essentially contains magnesium oxide and yttrium oxide in the crystal phase control powder in order to facilitate sintering and crystal phase control of the silicon nitride molded body, and the magnesium oxide and yttrium oxide make the manufactured silicon nitride sintered body more dense and high density. It has the advantage of being able to further improve the thermal conductivity of the silicon nitride sintered body by reducing the amount of residual grain boundary phase during sintering.

In addition, the silicon-containing ceramic composition includes at least one of iron oxide (Fe ₂ O ₃ ) and titanium oxide (TiO ₂ ) in order to improve mechanical strength due to thermal stress or thermal shock according to a semiconductor manufacturing process, which becomes severe. It may further contain a strength-enhancing powder, and preferably, the strength-enhancing powder may contain both iron oxide and titanium oxide.

In particular, step (4) described later proceeds in one step through continuous heat treatment in one sintering furnace without nitriding and sintering in a separate furnace. A combination of magnesium oxide and yttrium oxide, or magnesium oxide, yttrium oxide, iron oxide and Combinations of titanium oxide may be useful for nitriding and sintering metallic silicon powders to silicon nitride. That is, instead of carrying out nitriding and sintering in separate furnaces or performing nitriding and then cooling and sintering, a one-step process in which a silicon-containing ceramic composition is charged into a furnace and then nitriding and sintering is performed in one step is uniform throughout the inside of the molded body. It may not be easy to implement a densified sintered body without elution of silicon while being nitrided in a uniform manner. can be useful for implementing To this end, preferably, 2 to 5 mol% of yttrium oxide and 4 to 8 mol% of magnesium oxide may be included in the ceramic composition. In addition, when iron oxide and titanium oxide are further contained, 0.1 to 3 mol% of iron oxide and 1 to 5 mol% of titanium oxide may be further included based on the total number of moles of the ceramic composition, and through this, further improvement is achieved even though the nitriding-sintering one-step process is performed. mechanical strength can be achieved. If the content of yttrium oxide is less than 2 mol%, it may be difficult to realize a densified sintered body during sintering through a one-step process, and it is difficult to capture oxygen on the grain boundary. Strength may also be reduced. In addition, if the amount of yttrium oxide exceeds 5 mol%, there is a concern that the grain boundary phase is increased and the thermal conductivity and fracture toughness of the silicon nitride sintered body are reduced. In addition, when the magnesium oxide is less than 4 mol%, both thermal conductivity and mechanical strength of the implemented silicon nitride sintered body may be low, silicon may be eluted during nitriding, and it may be difficult to manufacture a densified substrate. In addition, if the magnesium oxide exceeds 8 mol%, the residual amount of magnesium increases at the grain boundary during sintering, and as a result, the thermal conductivity of the sintered body may be lowered, sintering itself is not easy, and fracture toughness may be lowered. . Also, if iron oxide is less than 0.1 mol% and/or titanium oxide is less than 1 mol%, improvement in mechanical strength may be insignificant. Also, if the content of iron oxide exceeds 3 mol% and/or the content of titanium oxide exceeds 5 mol%, there is a possibility that the mechanical strength of the sintered body may decrease.

In addition, preferably, the yttrium oxide and magnesium oxide may be included in the composition in a molar ratio of 1: 1.5 to 2.0, and through this, it may be more advantageous to achieve the object of the present invention.

In addition, the rare earth element-containing compound powder, magnesium-containing compound powder, iron oxide powder, and titanium oxide powder may each independently have an average particle diameter of 0.1 to 1 μm, which may be more advantageous in achieving the object of the present invention. there is.

The first ceramic layer 10 may be manufactured through a commonly known method for manufacturing a ceramic sheet having a predetermined thickness using a ceramic composition. For example, the first ceramic layer 1 is formed by cold isostatic pressing (CIP) molding of a ceramic composition in powder form, or a slurry containing an organic binder is produced as a green sheet through a tape casting method. After that, it may be manufactured by laminating a plurality of sheets to have a desired thickness. In this case, the slurried ceramic composition containing the organic binder may be prepared by mixing the organic binder non-solvent with the ceramic composition described above. The solvent and organic binder may be used without limitation in the case of a known solvent and organic binder used in manufacturing a ceramic molded body or ceramic green sheet. Specifically, the solvent serves to adjust the viscosity by dissolving the organic binder and dispersing the mixed raw material powder. For example, terpineol, dihydro terpineol (DHT), dihydro terpineol Dihydro terpineol acetate (DHTA), Butyl Carbitol Acetate (BCA), ethylene glycol, ethylene, isobutyl alcohol, methyl ethyl ketone, butyl carbitol, texanol (2,2,4 -trimethyl-1,3-pentanediol monoisobutyrate), ethylbenzene, isopropylbenzene, cyclohexanone, cyclopentanone, dimethylsulfoxide, diethylphthalate, toluene, mixtures thereof and the like can be used. At this time, it is preferable to mix 50 to 100 parts by weight of the solvent based on 100 parts by weight of the ceramic composition. If the content of the solvent is less than 60 parts by weight, the viscosity of the slurry is high, making it difficult to manufacture a molded body, and in particular, it may be difficult to control the thickness of the molded body. If the content of the solvent exceeds 100 parts by weight, the viscosity of the slurry becomes too thin. It takes a long time to dry, and it may be difficult to control the thickness of the ceramic green sheet.

In addition, the organic binder functions to bind the ceramic composition in a sheet shape in the prepared slurry. The organic binder is preferably mixed in an amount of 5 to 20 parts by weight based on 100 parts by weight of the ceramic composition. The organic binder may be a cellulose derivative such as ethyl cellulose, methyl cellulose, nitrocellulose, or carboxycellulose, or a polymer resin such as polyvinyl alcohol, acrylic acid ester, methacrylic acid ester, or polyvinyl butyral. In addition, the slurried ceramic composition may further include a known material contained in a slurry for preparing a molded body using ceramics, such as a dispersant and a plasticizer, and the present invention is not particularly limited thereto.

In addition, the first ceramic layer 10 may have a thickness of, for example, 5 to 15 mm, but is not limited thereto, and may be appropriately changed in consideration of the size of the ceramic plate and the like.

A pattern portion for accommodating the resistance heating element 40 on one surface of the first ceramic layer 10 manufactured thereafter and including a groove extending along the surface of the first ceramic layer 10 and having a predetermined width and depth ( 10a) is engraved (Fig. 3 (b)). The grooves for forming the pattern portion 10a are engraved by a known method, for example, through press molding by the remaining thickness except for the portion 10b of the first ceramic layer 10, or the portion 10b ) may be implemented by laminating a ceramic layer having a thickness corresponding to ) and a ceramic layer having a groove pattern corresponding to the pattern portion 10a.

At this time, the groove may be formed to correspond to the buried pattern of the resistance heating element 40 to be provided. For example, the resistance heating element 40 may have a buried pattern employed in a known ceramic heater or a known electrostatic chuck heater. For example, as shown in FIG. 1, the groove is continuously formed such that both ends of one continuous resistance heating element 40 are drawn out from the center of the first ceramic layer 10 and then buried symmetrically outward on the same plane. It can be. Alternatively, unlike that shown in FIG. 1 , two or more resistance heating elements may be discontinuously formed so as to be buried in a predetermined pattern in order to control the temperature differently according to regions. In this case, the shape of the specific pattern formed by the grooves may be a known ceramic heater in the case where two or more resistance heating elements are provided, or a buried pattern employed in a known electrostatic chuck heater, so the present invention is not particularly limited thereto. . For example, the first ceramic layer 10 is divided into three or more fan-shaped areas based on the center, or divided into a plurality of concentric annular areas based on the center, or divided by dividing the annular area into radial line segments. You may.

In addition, the depth (h) and width (w) of the groove may be greater than the height and width of the resistance heating element to be buried in step (2) described below in a cross section perpendicular to the direction in which the groove extends. For example, the resistance heating element When the cross section is circular, the depth (h) and width (w) of the groove may be greater than the diameter (R) of the resistance heating element. For example, the depth (h) of the groove may be 3 to 5 mm and the width (w) may be 3 to 5 mm, but is not limited thereto.

On the other hand, if the depth (h) and width (w) of the groove are formed to be greater than the height and width of the cross section of the resistance heating element, a space is secured in which the filler containing silicon provided with the resistance heating element can surround the resistance heating element. This is to prevent the formation of voids inside the groove. In other words, the thermal properties such as the coefficient of thermal expansion may be different between the sintered silicon nitride sintered body and the resistance heating element, and in this case, the high temperature heat applied during nitriding and sintering through step (4) described later or Due to the heat generated by the heat and/or the high-temperature external environment in which the ceramic heater is used, damage such as cracks may occur in the silicon nitride sintered body or the shape deformation of the resistance heating element may occur, resulting in temperature deviation for each position of the ceramic heater plate. Since the area of the cross section of the groove is larger than the area of the cross section of the resistance heating element, a space in which the resistance heating element can be sufficiently surrounded by a filling material capable of minimizing or preventing such concerns can be provided. In addition, since the filler can be easily filled without empty space inside the groove, it is possible to prevent generation of voids inside the groove after sintering. Therefore, preferably, the depth (h) and width (w) of the cross section of the groove are 5 to 20% larger based on the height and width of the cross section of the resistance heating element or based on the diameter (R) of the resistance heating element having a circular cross section. can be formed If the depth (h) and width (w) of the cross section of the groove are each less than 5% based on the diameter (R) of the resistance heating element (or the height and width of the cross section of the resistance heating element), the resistance heating element under high temperature conditions It is difficult to offset the difference in thermal characteristics between the sintered body and silicon nitride, and voids may be generated after sintering due to unfilled parts inside the grooves. In addition, if the depth (h) and width (w) of the cross section of the groove are formed to be greater than 20%, respectively, based on the diameter (R) of the resistance heating element (or the height and width in the cross section of the resistance heating element), the slurry or paste phase When the filler is filled, the position of the resistance heating element, which must be fixed in position, is easily changed, so the position of the resistance heating element changes after sintering.

Next, as step (2) according to the present invention, the resistance heating element 40 and the resistance heating element 40 are placed in the groove of the pattern portion 10a and the filler 60 containing silicon filling the remaining space of the groove in which the resistance heating element 40 is accommodated. Steps are performed ((c), (d) in FIG. 3).

The resistance heating element 40 may employ a known ceramic heater or a resistance heating element used in a known electrostatic chuck heater without limitation in material and shape. For example, tungsten, molybdenum, tungsten alloy, molybdenum alloy, copper, titanium may be formed by In addition, it may be a wire having a circular or rectangular cross section or a coil in which such a wire is wound around one axis. For example, when a resistance heating element in the form of a coil is provided, the diameter of the wire may be 0.1 to 1 mm, the inner diameter of the coil may be 1 to 5 mm, and the pitch may be 0.5 to 10 mm, but is not limited thereto.

In addition, the filler containing silicon may form a filled sintered body of silicon nitride through step (4) described later, and the density after sintering is designed to be different from the density after sintering the first ceramic layer 10 described above. can Preferably, the filler containing silicon may be designed such that the density after sintering is smaller than the density after the first ceramic layer 10 is sintered. For example, based on solid content, silicon nitride (Si ₃ N ₄ ) powder 92 to 95 weight %, 2 to 5% by weight of yttrium oxide and 1 to 3% by weight of titanium oxide.

In step (2), the above-described resistance heating element 40 is first arranged to be accommodated in the groove (FIG. 3(c)), and then the remaining space of the groove in which the resistance heating element 40 is disposed is filled with a filler 60 containing silicon. ) It may be performed in a manner of embedding (FIG. 3(d)), and at this time, the filling material 60 containing silicon may be filled in the remaining space of the groove through screen printing, for example.

Alternatively, differently from that shown in FIG. 3, step (2) separately manufactures a filler in which a filler containing silicon is solidified in a size accommodated in the groove so that the resistance heating element is buried therein, and then inserts the filler into the groove. can be performed with At this time, after placing the resistance heating element 40 in the groove of the jig molded to have the same size and pattern shape as the cross section of the groove, the filling composition 60 containing silicon is filled in the groove of the jig and After solidification, the jig may be separated to obtain a filler in which the resistance heating element 40 is embedded. In this case, in case the filler 60 containing silicon is directly filled in the first ceramic layer 10, the filler prepared through the dual process can be placed in the groove in an assembly method, so that the resistance heating element 40 and silicon There is an advantage that the arrangement of the containing filler 60 can be made easier.

Next, as step (3) according to the present invention, a second ceramic layer 2 containing silicon is disposed to cover one surface of the first ceramic layer 10 in the direction in which the resistance heating element 40 is disposed, and then A step of manufacturing the joined ceramic molded body 100 is performed ((e), (f) of FIG. 3).

The second ceramic layer 20 forms a part of the silicon nitride sintered body through step (4), which will be described later, and may be formed through the ceramic composition and method described in the above-described first ceramic layer 10. In addition, the second ceramic layer 20 may have a thickness of 3 to 5 mm, but is not limited thereto. In addition, the temporary bonding may be performed through a known method of manufacturing a molded body by laminating conventional ceramic sheets and then applying pressure. For example, it may be performed through a stacking machine to increase molding density For this purpose, cold isostatic press (CIP) molding or warm isostatic press (WIP) may be further performed. On the other hand, it should be noted that it can also be performed through CIP or WIP without pressurization through the laminating machine.

Meanwhile, step (3) includes 3-1) disposing an intermediate ceramic layer 30 containing silicon on one surface of the first ceramic layer 10, 3-2) on the intermediate ceramic layer 30 The step of disposing the electrode 50, and 3-3) disposing the second ceramic layer 20 on the electrode 50 and then bonding the ceramic layers together to manufacture the molded body 100'.

The intermediate ceramic layer 30 is a layer covering one surface of the first ceramic layer 10 on which the pattern portion 10a is formed, and forms a part of the silicon nitride sintered body through step (4) described later, and the first ceramic layer ( 10) may be formed through the ceramic composition and method described above. Alternatively, the intermediate ceramic layer 30 is the first ceramic layer 10 and/or the second ceramic layer 20 to prevent leakage of current transmitted from one of the electrode 50 and the resistance heating element 40 to the other. ) and may be formed to have a different composition.

In addition, the intermediate ceramic layer 30 may have a thickness of 1 to 10 mm, but is not limited thereto.

In addition, the electrode 50 may be an RF electrode used to generate plasma or an electrostatic electrode for adsorbing a substrate such as a wafer onto one surface of a ceramic heater plate. The size, material, and shape of the electrode may be any size, material, or shape of an electrode embedded in a known ceramic heater plate or an electrostatic chuck heater without limitation, and the present invention is not particularly limited thereto. For example, when the electrode is an electrostatic electrode, the material may be any one of molybdenum, tungsten, molybdenum alloy, and tungsten alloy, and two electrode plates having a mesh shape or the same shape are spaced apart from each other by a predetermined distance based on the center. can

The ceramic molded bodies 100 and 100' prepared through the above-described step (3) may further perform a degreasing process for removing organic compounds such as organic binders in the ceramic molded bodies 100 and 100' before performing the step (4) described later. .

Specifically, in the degreasing process, the prepared ceramic molded bodies 100 and 100' may be degreased by mounting the prepared ceramic molded bodies 100 and 100' on degreasing and then heating them from the heat treatment start temperature to 900° C. while varying a predetermined temperature increase rate or a temperature increase rate. In addition, the degreasing process may be performed under a known atmosphere, for example, an air atmosphere and/or a nitrogen atmosphere, and a specific atmosphere may be appropriately selected in consideration of the type and content of the organic binder used. However, considering the composition of the above-described ceramic molded bodies 100 and 100', the type and content of the organic binder, and the like, the degreasing process is preferably performed under an air atmosphere in the temperature range of 450 ° C from the heat treatment start temperature, and 450 ° C to 450 ° C. In the temperature range of 900° C., degreasing may be performed under a nitrogen atmosphere, and through this, it may be advantageous to minimize or completely remove the carbon component remaining in the ceramic molded bodies 100 and 100' after the degreasing process. The heat treatment start temperature may be room temperature, for example, 20 to 25 °C. In addition, during the heat treatment, the temperature may be raised at a rate of 2 to 8 ° C / min up to 450 ° C, the temperature may be raised at a rate of 2 to 8 ° C / min from 450 ° C to 900 ° C, and the heating rate up to 450 ° C and 450 ° C The heating rates from °C to 900 °C may be the same or different from each other.

Next, as step (4) according to the present invention, the ceramic molded body (100,100') prepared through step (3) or the ceramic molded body (100,100') after the degreasing process is nitrided and sintered to form silicon nitride (Si ₃ N ₄ ) ceramic Steps for preparing a sintered body are performed.

In step (4), a known nitriding and sintering process of nitriding and sintering a ceramic composition containing silicon with silicon nitride may be employed without limitation. At this time, the nitriding and sintering may be performed in a separate furnace or discontinuously in one furnace, that is, in a manner of re-sintering the cooled silicon nitride molded body after nitriding. However, preferably, the nitriding and sintering may be performed as a one-step process performed continuously in one furnace so that mass production is possible by reducing manufacturing time and man-hours, and for this purpose, step (4) is nitrogen at a predetermined pressure A first heat treatment section in which the ceramic molded bodies 100 and 100′ are converted to silicon nitride (Si ₃ N ₄ ) by heat treatment at a first temperature of 1300 to 1500 ° C. while applying gas, and a second temperature of 1700 to 1900 ° C. to obtain a ceramic molded body ( 100, 100') may be performed through a heat treatment step including a second heat treatment section for sintering.

Referring to FIG. 6, the heat treatment step includes a first heat treatment section S ₃ in which the ceramic molded bodies 100 and 100' are mounted in a sintering furnace and then converted into silicon nitride (Si ₃ N ₄ ) and the nitrided ceramic molded bodies 100 and 100'. ) Is subjected to a heat treatment step including a second heat treatment section (S ₅ ) for sintering, and the heat treatment step is the first heat treatment section (S ₃ ) before the first heating section (S ₁ ) and the second heating section (S _{2 )} ), and a third heating section (S 4 ) between the first heat treatment section (S ₃ ) and the second heat treatment section ( _{S 5 )} and a cooling section (S ₆ ) after the second heat treatment section (S ₅ ) are further included. can do.

In order for the heat treatment step (4) to be performed as a one-step process, the nitriding process of nitriding the ceramic molded bodies 100 and 100' into silicon nitride molded bodies and the sintering process of sintering the nitrided molded bodies are all performed in one furnace. Conventional silicon nitride sintered body is common to be implemented by a two-step method for producing a silicon nitride sintered body by manufacturing a molded body using the prepared silicon nitride powder after manufacturing silicon powder into silicon nitride powder, and then sintering it. However, the second-stage method requires a long manufacturing time because the silicon nitride powder needs to be further cooled and crushed until it is realized as a sintered body after manufacturing the silicon nitride powder, which increases the manufacturing cost and is not suitable for mass production. Nevertheless, the reason for using such a two-step method is that silicon nitride powders having more uniform characteristics can be easily produced when nitriding on small-sized powders, so that the finally manufactured silicon nitride sintered body also has uniform characteristics. because it was advantageous.

The manufacturing method according to an embodiment of the present invention avoids the two-step method that was inevitably adopted in order to realize a silicon nitride sintered body having uniform characteristics in the prior art, and performs both the nitriding process and the sintering process with a one-step heat treatment method. It is possible to manufacture a silicon nitride sintered body, and through this, a ceramic heater plate or an electrostatic chuck heater plate having uniform characteristics can be implemented while significantly reducing manufacturing time.

In detail about the heat treatment step (4), the prepared ceramic molded bodies 100 and 100' are mounted in a sintering furnace and vary a predetermined temperature increase rate or temperature increase rate until reaching the first heat treatment section S ₃ , It may include a first temperature-rising section (S ₁ ) and a second temperature-raising section (S ₂ ) subjected to heat treatment. Specifically, the first temperature rising section (S ₁ ) may be, for example, heat treatment from a heat treatment start temperature at room temperature to a predetermined temperature (T ₁ ), for example, a temperature of 1000 ± 70 ° C, preferably 1000 ± 20 ° C. In addition, there is no limit on the temperature increase rate up to the predetermined temperature (T ₁ ), and the temperature increase conditions applied during nitriding of general silicon powder may be followed, for example, the temperature is increased at a rate of 4 ° C / min to 30 ° C / min. can Also, in this section, the temperature may be raised under an inert gas or nitrogen gas atmosphere when the temperature is raised.

On the other hand, when the above-described degreasing process is performed by heat treatment to a temperature of 900 ° C, the first heating section (S ₁ ) is heated from the heat treatment start temperature to the temperature section of 900 ° C, then 900 ° C to 1000 ± 70 ° C, preferably 900 ° C Secondary degreasing may be further performed at ~ 1000 ± 20 ° C. In addition, in the case of secondary degreasing, unlike that shown in FIG. 6, in the section of 900 ° C to 1000 ± 70 ° C in the first temperature rising section (S ₁ ), 1 to 10 ° C / min, more preferably 1 to 3 ° C It is preferable to raise the temperature at a low rate of / min, and the temperature may be raised at a rate of 4 to 30 ° C up to 900 ° C. In addition, the secondary degreasing may be performed under a nitrogen atmosphere, and at this time, the nitrogen pressure is preferably 0.1 to 0.2 MPa, more preferably 0.14 to 0.17 MPa.

In addition, the second temperature rising period (S ₂ ) in which the temperature is raised from a predetermined temperature (T 1 ) to the first temperature (T ₂ ) is specifically 1000 ± 70 ℃, more preferably from a temperature of 1000 ± 20 ℃ to _the first temperature (T ₂ ) The temperature may be raised at a slow rate while applying nitrogen gas at a predetermined pressure, specifically at a pressure of 0.1 to 0.2 MPa, more preferably at a pressure of 0.14 to 0.18 MPa. there is. In addition, the temperature may be raised at a rate of 0.1 to 2.0°C/min, more preferably 0.5 to 1.0°C/min. If the nitrogen gas pressure is less than 0.1 MPa, even after passing through the first heat treatment section (S ₃ ), the ceramic molded bodies 100 and 100' may not be completely nitrided, so that non-nitrided portions may exist. In addition, when the nitrogen gas pressure exceeds 0.2 MPa, a phenomenon in which silicon is eluted may occur, and thermal conductivity and mechanical strength of the finally manufactured silicon nitride sintered body may be lowered. In addition, if the heating rate from 1000 ± 70 ℃ to the first temperature (T ₂ ) is less than 0.1 ℃ / min, the time required for the heat treatment step may be excessively extended. In addition, when the temperature increase rate exceeds 2.0 ° C./min, silicon is eluted and it may be difficult to manufacture a molded body completely nitrided with silicon nitride.

Thereafter, after the temperature is raised to the first temperature (T ₂ ), a nitriding process corresponding to the first heat treatment section (S ₃ ) in which the heat treatment is performed at the first temperature (T ₂ ) while applying nitrogen gas at a predetermined pressure is performed. The first temperature T ₂ may be a predetermined temperature in the range of 1300 to 1500°C, preferably in the range of 1400 to 1500°C. If the first temperature T ₂ is less than 1300° C., nitriding may not occur uniformly. In addition, when the first temperature T ₂ exceeds 1500° C., densification of the sintered body may be difficult as the β crystal phase is rapidly formed.

In addition, the pressure of the nitrogen gas applied in the first heat treatment section (S ₃ ) may be applied at a pressure of 0.1 to 0.2 MPa, more preferably at a pressure of 0.14 to 0.18 MPa. If the nitrogen gas pressure is less than 0.1 MPa, nitridation does not occur completely, and a non-nitrided portion may exist. In addition, when the nitrogen gas pressure exceeds 0.2 MPa, a phenomenon in which silicon is eluted during the nitriding process may occur, and thermal conductivity and mechanical strength of the sintered body may be reduced. In addition, the nitriding process may be performed for 2 to 10 hours, more preferably for 1 to 4 hours. Meanwhile, the time of the nitriding process may be appropriately adjusted according to the first temperature T ₂ .

In addition, according to an embodiment of the present invention, the second temperature rising section from 1000 ± 70 ° C., more preferably 1000 ± 20 ° C. corresponding to the predetermined temperature (T ₁ ) to the first temperature (T ₂ ) The pressure of the nitrogen gas applied in (S ₂ ) may be lower than the pressure of the nitrogen gas applied in the first heat treatment section (S ₃ ), and through this, more uniform nitriding and excellent appearance and mechanical strength Implement a silicon nitride sintered body It may be advantageous to do so.

In addition, after the nitriding process, the sintering process is performed to the second temperature (T ₃ ) It may include a third temperature rising section (S ₄ ) heat treatment at a predetermined temperature rising rate. At this time, according to a preferred embodiment of the present invention, the third temperature rising section (S ₄ ) from the first temperature (T ₂ ) to the second temperature (T ₃ ) raises the temperature at a slow rate while applying nitrogen gas at a predetermined pressure It can be, specifically, it can be heated at a rate of 0.1 to 10.0 ℃ / min under nitrogen gas at a pressure of 0.1MPa to 1.0MPa. If the nitrogen gas pressure is less than 0.1 MPa, it may be difficult to suppress decomposition of silicon nitride. In addition, if the nitrogen gas pressure exceeds 1.0 MPa, the pressure resistance of the furnace may be a problem. In addition, if the heating rate from the first temperature T ₂ is less than 0.1 °C/min, the time required for the heat treatment step may be excessively extended. In addition, when the heating rate exceeds 10.0 °C/min, a rapid transition to the beta phase occurs, and as a result, crystal control may not be easy, such as non-uniform growth of beta phase crystals, and the implemented silicon nitride sintered ceramic heater plate Alternatively, it may be difficult to have desired physical properties required for the electrostatic chuck heater plate.

In addition, according to an embodiment of the present invention, the third temperature rising section (S ₄ ) from the first temperature (T ₂ ) to the second temperature (T ₃ ) may be subdivided into two sections and performed, thereby providing more excellent A silicon nitride sintered body having physical properties can be manufactured.

Specifically, the first heat treatment section (S ₃ ) and the second heat treatment section (S ₅ ) between the first temperature (T ₂ ) to 1700 ± 20 ℃ under a nitrogen gas pressure of 0.15 ~ 0.3MPa 0.1 ~ 10.0 ℃ / min. The first contraction period (S _4-1 ) where the temperature is raised at a rate of 1700 ± 20 ℃ to the second temperature (T ₃ ) Under a nitrogen gas pressure of 0.8 ~ 0.98MPa, the second contraction temperature is raised at a rate of 1 ~ 10 ℃ / min A section (S _4-2 ) may be further included.

At this time, the first contraction period (S _4-1 ) may have a nitrogen gas pressure of 0.15 to 0.3 MPa, and the second contraction period (S _4-2 ) may be performed at a nitrogen gas pressure of 0.8 to 0.9 MPa. In addition, the first contraction period (S _4-1 ) may be performed at a heating rate of 0.1 to 10 °C/min, more preferably 0.1 to 2 °C/min. In addition, in the second contraction period (S _4-2 ), the temperature may be raised at 1 to 10 °C/min, more preferably at 1 to 5 °C/min, and through this, it may be easy to achieve the object of the present invention. .

Next, the second heat treatment section (S ₅ ), which is a sintering process performed after reaching the second temperature (T ₃ ), will be described.

The second temperature T ₃ may be selected within a range of 1800 to 1900°C. If the temperature is less than 1800 ° C., the silicon nitride molding may not be sufficiently densified. In addition, when the temperature exceeds 1900 ° C., overgrowth and / or non-uniform growth of particles is concerned, and mechanical strength of the implemented silicon nitride sintered body may be lowered.

At this time, the sintering time may be adjusted depending on the range of the above-described second temperature (T ₃ ). When the second temperature (T ₃ ) is low, sintering may be performed for a long time, and conversely, the second temperature (T _{3 )} ), sintering can be performed for a relatively short time compared to the sintering time under low temperature conditions. The sintering may be carried out for, for example, 2 to 10 hours, more preferably 4 to 8 hours, and through this, it is advantageous to achieve the object of the present invention.

In addition, the sintering process should also be performed under a nitrogen gas atmosphere in order to suppress the decomposition of silicon nitride according to the sintering temperature. Nitrogen gas may be added to, more preferably 0.9 ~ 1.0MPa, more preferably sintering under a nitrogen gas pressure of 0.9 ~ 0.98MPa, through which it may be more advantageous to implement a high-quality silicon nitride sintered body. .

The substrate roughened up to the second heat treatment section (S- ₅ ) of the heat treatment step may then further undergo a cooling section (S ₆ ), the cooling section (S ₆ ) may follow cooling conditions after sintering of a conventional silicon nitride sintered body, The present invention is not particularly limited in this regard.

Referring to FIG. 5 , the ceramic heater plate 200 manufactured through the above-described method includes a body 210 which is a plate-shaped silicon nitride (Si ₃ N ₄ ) sintered body, and a resistance heating element embedded in the body 210. (40). At this time, the body 210 is composed of a first part 212 that surrounds at least a portion of the resistance heating element 40 and a second part 211 that is the remaining part, and the density of the first part 212 and the second part The density of (211) is implemented differently.

Preferably, the density of the first part 212 is implemented smaller than the density of the second part 211, and through this, the sintered body according to the difference in thermal characteristics between the silicon nitride sintered body 210 and the resistance heating element 40 It may be advantageous to prevent damage such as cracks or shape deformation of the resistance heating element 40 .

In addition, the first portion 212 may be porous to have a lower density.

In addition, the density of the first portion 211 may be 5% or more smaller than the density of the second portion 212, and through this, it may be more advantageous to achieve the object of the present invention. If the density of the first portion 211 is smaller than the density of the second portion 212 by less than 5%, it may not be sufficient to solve the above-mentioned problem caused by the difference in thermal characteristics.

On the other hand, the silicon nitride sintered body realized by the above-described manufacturing method has a thermal conductivity of 75 W / mK or more, preferably 80 W / mK or more, more preferably 90 W / mK or more, and a three-point bending strength of 650 MPa or more, preferably Preferably it may be 680 MPa or more, more preferably 700 MPa or more, and more preferably 750 MPa or more. In addition, the second portion 211 in the body 210 preferably has a silicon content of 6% by weight or less, more preferably 4% by weight or less, and even more preferably 0% by weight, thereby improving mechanical strength and may have thermal conductivity.

In addition, the ceramic heater plate 200 described above may be implemented as a semiconductor holding device. The semiconductor holding device may further include a known configuration other than the ceramic heater plate 200, and the present invention is not particularly limited thereto. For example, the known configuration may be a known cooling member for regulating the temperature of a semiconductor wafer held on one surface of the ceramic heater plate 200, and the cooling member may include a cooling substrate made of aluminum or titanium and an inside of the cooling substrate. A passage through which a refrigerant may flow may be formed. In addition, the known configuration may include, for example, a power source capable of applying current to the electrode 50 and the resistance heating element 40, a focus ring mounting table, and a mounting plate supporting them.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments presented herein, and those skilled in the art who understand the spirit of the present invention may add elements within the scope of the same spirit. However, other embodiments can be easily proposed by means of changes, deletions, additions, etc., but these will also fall within the scope of the present invention.

10: first ceramic layer 20: second ceramic layer
30: intermediate ceramic layer 40: resistance heating element
50: electrode 60: filler containing silicon
100,100': ceramic molded body 200: ceramic heater plate
210: body

Claims (19)

(1) forming a pattern part by engraving a groove having a predetermined width and depth extending along one surface of the first ceramic layer containing silicon;
(2) disposing a resistance heating element and a filler containing silicon filling the remaining space of the groove accommodating the resistance heating element in the groove;
(3) preparing a ceramic molded body by temporarily bonding a second ceramic layer containing silicon on one surface of the first ceramic layer; and
(4) manufacturing a silicon nitride (Si ₃ N ₄ ) ceramic sintered body by nitriding and sintering the ceramic molded body. According to claim 1,
In step (2), after placing the resistance heating element in the groove, the remaining space of the groove in which the resistance heating element is disposed is filled with a filler containing silicon, or
A method of manufacturing a ceramic heater plate performed by inserting a filling body having a cross-sectional size accommodated in the groove and in which a filling material containing silicon is solidified so that a resistance heating element is buried therein, into the groove. The method of claim 1, wherein step (3) is
3-1) disposing an intermediate ceramic layer containing silicon on one surface of the first ceramic layer;
3-2) disposing an electrode on the intermediate ceramic layer; and
3-3) disposing a second ceramic layer on the electrode and then temporarily bonding the ceramic layers together; According to claim 1,
The method of manufacturing a ceramic heater plate in which the grooves are continuously or discontinuously formed. According to claim 1,
In order to secure a space for the ceramic filling composition to surround the resistance heating element and prevent voids from being created inside the groove, the depth and width of the groove in the cross section perpendicular to the direction in which the groove extends are greater than the height and width of the resistance heating element disposed in the groove. A method for manufacturing the formed ceramic heater plate. According to claim 1,
Each of the first ceramic layer and the second ceramic layer is a laminate of one or several ceramic green sheets,
A method of manufacturing a ceramic heater plate, wherein the thickness of the first ceramic layer is 5 to 15 mm and the thickness of the second ceramic layer is 3 to 5 mm. According to claim 1,
The method of claim 1 , wherein the first ceramic layer and the second ceramic layer include metal silicon powder, and crystalline phase control powder including a rare earth element-containing compound and a magnesium-containing compound. According to claim 7,
The rare earth element-containing compound is yttrium oxide, the magnesium-containing compound is magnesium oxide, and the ceramic heater includes 2 to 5 mol% of yttrium oxide and 4 to 8 mol% of magnesium oxide based on the total number of moles of the ceramic composition. Plate manufacturing method. According to claim 8,
It further includes a strength enhancing powder containing at least one of iron oxide (Fe ₂ O ₃ ) and titanium oxide (TiO ₂ ), and 0.1 to 3 mol% of iron oxide (Fe ₂ O ₃ ) and oxide based on the total number of moles of the ceramic composition. A method of manufacturing a ceramic heater plate containing 1 to 5 mol% of titanium (TiO ₂ ). According to claim 1,
The filler containing silicon includes 92 to 95% by weight of silicon nitride (Si ₃ N ₄ ) powder, 2 to 5% by weight of yttrium oxide, and 1 to 3% by weight of titanium oxide. According to claim 1,
Step (4) is a first heat treatment section in which the ceramic molded body is converted to silicon nitride (Si ₃ N ₄ ) by heat treatment at a first temperature of 1300 to 1500 ° C. while applying nitrogen gas at a predetermined pressure, and a second temperature of 1700 to 1900 ° C. A method of manufacturing a ceramic heater plate performed through a heat treatment step including a second heat treatment section in which the ceramic molded body is sintered by heat treatment. According to claim 11,
The heat treatment step is a ceramic heater plate manufacturing method in which heat treatment is performed at a heating rate of 0.1 to 2 ° C / min while applying nitrogen gas at a pressure of 0.1 to 0.2 MPa from 1000 ± 20 ° C to the first temperature. According to claim 11,
In the first heat treatment section, nitrogen gas is applied at a pressure of 0.1 to 0.2 MPa, and the first heat treatment section is performed for 2 to 10 hours. According to claim 11,
The method of manufacturing a ceramic heater plate in which the pressure of nitrogen gas applied from the 1000 ± 20 ° C. to the first temperature is lower than the pressure of nitrogen gas applied in the first heat treatment section. According to claim 11,
Between the first heat treatment section and the second heat treatment section, the temperature is raised from the first temperature to 1700 ± 20 ° C at a rate of 0.1 to 10.0 ° C / min under a nitrogen gas pressure of 0.15 to 0.30 MPa and at 1700 ± 20 ° C. A method of manufacturing a ceramic heater plate, further comprising a second contraction period in which the temperature is raised to a second temperature at a rate of 1 to 10° C./min under a nitrogen gas pressure of 0.80 to 0.98 MPa. A plate-shaped silicon nitride (Si ₃ N ₄ ) sintered body; and
A resistance heating element embedded in the body; includes,
The ceramic heater plate of claim 1 , wherein the body includes a first portion that surrounds at least a portion of the resistance heating element and a second portion that is the remaining portion, wherein a density of the first portion and a density of the second portion are different. According to claim 16,
The ceramic heater plate of claim 1 , wherein a density of the first portion is smaller than a density of the second portion. According to claim 16,
A ceramic heater plate further comprising an electrode inside the body. An electrostatic chuck heater comprising a ceramic heater plate according to any one of claims 16 to 18.

Images