Ceramic susceptor with hybrid coating

Abstract

To provide a ceramic susceptor which, compared to conventional ceramic susceptors, not only excels in volume resistance at high temperatures and thermal conductivity at room temperature, but also can improve plasma resistance and particle resistance by forming a stable coating interface between a coating layer contained in the susceptor and a sintered body.SOLUTION: A ceramic susceptor is disclosed which, compared to conventional ceramic susceptors, not only exhibits superior volume resistance at high temperatures and thermal conductivity at room temperature, but also possesses excellent plasma resistance without coating layer delamination even in high-temperature environments, thereby providing a particle reduction effect.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a ceramic susceptor including a hybrid coating, and more particularly to a ceramic susceptor including a hybrid coating that not only has superior volume resistance at high temperatures and thermal conductivity at room temperature compared to conventional ceramic susceptors, but also improves plasma resistance and reduces particle generation. [Background technology]

[0002] In recent years, semiconductor processes have become more miniaturized and highly integrated to improve yield, and as equipment diameters have increased, the use of high-power plasma has become unavoidable, and processes are being carried out in harsh, high-temperature environments.

[0003] Vacuum plasma devices using high-temperature plasma are widely used in the field of semiconductor device etching and other processes for realizing ultrafine shapes. These vacuum plasma devices include plasma enhanced chemical vapor deposition (PECVD) devices that form deposition films on substrates using plasma-based chemical vapor deposition, sputtering devices that form deposition films using physical methods, and dry etching devices that etch substrates or materials coated on substrates into specific patterns.

[0004] High-temperature plasma is generated inside such vacuum plasma devices, which can easily damage the chamber and the components inside it. Furthermore, certain elements and contaminant particles are likely to be generated from the surfaces of the chamber and the components inside it, contaminating the interior of the chamber. In particular, in the case of plasma etching devices, reactive gases such as F and Cl are injected into the plasma atmosphere, exposing the inner walls and components inside the chamber to a highly corrosive environment. This corrosion typically primarily results in chemical and physical damage to the chamber and the components inside it, and secondarily generates contaminants and particles, which can lead to an increased defect rate and reduced quality of products manufactured through processes inside the chamber.

[0005] If the chamber or the components inside it are damaged, the damaged equipment must be replaced, cleaned, or repaired, resulting in additional costs and the process line must be stopped, increasing the processing time required for product manufacturing. For these reasons, the metal susceptors previously installed inside the chamber are being replaced with ceramic susceptors, such as aluminum nitride (AlN) sintered compacts and alumina (Al2O3) sintered compacts, which have excellent thermal conductivity. These ceramic susceptors are primarily used in heaters and electrostatic chucks for semiconductor manufacturing processes.

[0006] Aluminum nitride is stable at high temperatures and has excellent physical properties such as electrical insulation and thermal conductivity. It also has a thermal expansion coefficient similar to that of silicon, so it is mainly used in semiconductor manufacturing equipment, which requires high electrical resistance at high temperatures. Alumina is also stable at high temperatures and has better electrical insulation and higher hardness than aluminum nitride.

[0007] However, even these recent ceramic susceptors do not meet the ceramic properties, such as volume resistivity and thermal conductivity, required to withstand more severe high-temperature process environments. For example, aluminum nitride exhibits a rapid drop in volume resistivity at 500°C, resulting in a tendency for leakage current to occur, while alumina has a very low thermal conductivity of 20-30 W / mK at room temperature. If the thermal conductivity at room temperature is only 20-30 W / mK, there will be significant deviations in temperature uniformity, resulting in reduced yields and other problems. Furthermore, if the temperature uniformity deviation in thermal conductivity is large, thermal stress and thermal shock can result in a shortened product lifespan.

[0008] Furthermore, even when using ceramic components such as aluminum nitride sintered compacts or alumina sintered compacts, plasma still reduces their corrosion resistance, and halogen gases (e.g., F, Cl, Br, and I) generate contaminant particles on the surface of the component. To address this issue, the industry has attempted to improve plasma corrosion resistance by coating the surface of ceramic components with plasma corrosion-resistant fluorine-based materials such as YOF, AlF, LaF, and YF3, or yttrium oxide (Y2O3), using methods such as plasma spray coating, aerosol deposition, PVD, and CVD. However, in this case, due to the low relative density, the coating layer may peel off from the base material or form pores in the coating layer, reducing plasma corrosion resistance. Furthermore, the powder that makes up the coating layer may be lost, generating fine particles, and increasing process costs.

[0009] Therefore, even in recent semiconductor processes that use high-temperature environments and high-power plasma, there is a demand for ceramic members that have excellent volume resistivity and thermal conductivity, and that can have their surfaces coated with a component that has plasma corrosion resistance in a manner that prevents the coating layer from peeling off from the base material and does not generate fine particles, thereby improving plasma resistance and corrosion resistance against halogen gases. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Korean Patent No. 10-2369346 Summary of the Invention [Problem to be solved by the invention]

[0011] Therefore, an object of the present invention is to provide a ceramic susceptor that not only has superior volume resistance, particularly at high temperatures, and thermal conductivity at room temperature, compared to conventional ceramic susceptors, but also has improved plasma resistance and particle resistance by forming a stable coating interface between a coating layer contained in the susceptor and the sintered body. [Means for solving the problem]

[0012] To achieve the above object, the present invention provides a ceramic susceptor including a ceramic plate layer and a coating layer disposed on the ceramic plate layer, wherein the ceramic plate layer includes alumina (Al2O3) and aluminum nitride (AlN) but does not include an aluminum oxynitride phase (AlON phase), and the interface between the ceramic plate layer and the coating layer includes a reaction layer formed by reactive sintering. [Effects of the Invention]

[0013] The ceramic susceptor according to the present invention has advantages over conventional ceramic susceptors, such as excellent volume resistance at high temperatures and excellent thermal conductivity at room temperature, as well as a stable coating interface between the coating layer contained in the susceptor and the sintered body, thereby improving plasma resistance and particle resistance. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is an XRD graph showing the composition of a ceramic susceptor depending on the sintering temperature. [Figure 2] 1 is a graph showing the correlation between alumina content and sintering temperature. [Figure 3] 10A and 10B are photographs of the surface of Comparative Example 6 before and after heat treatment at 500° C. and scanning electron microscope (SEM) images of the bonding surface according to an example of the present invention. [Figure 4] 1A and 1B are photographs of the surface of Example 1 according to an embodiment of the present invention before and after heat treatment at 500° C. and SEM images of the bonding surface. [Figure 5] 10A and 10B are photographs of the surface of Example 5 according to an embodiment of the present invention before and after heat treatment at 500° C. and SEM images of the bonding surface. [Figure 6] FIG. 1 shows surface photographs, porosity, SEM images of bonding surfaces, and plasma resistance test results for Comparative Example 6 and Examples 1 to 5 according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will be described in detail below.

[0016] A ceramic susceptor according to one embodiment (first embodiment) of the present invention is a ceramic susceptor including a ceramic plate layer and a coating layer located on the ceramic plate layer, wherein the ceramic plate layer includes alumina (Al2O3) and aluminum nitride (AlN) but does not include an aluminum oxynitride phase (AlON phase), and includes a reaction layer formed by reactive sintering at the interface between the ceramic plate layer and the coating layer.

[0017] As semiconductor processes become increasingly miniaturized and highly integrated, the use of high-power plasma is unavoidable. Therefore, vacuum plasma equipment using high-temperature plasma is widely used for etching semiconductor devices and other ultra-fine feature creation. Therefore, in the industry, ceramic susceptors made of aluminum nitride (AlN) sintered body or alumina (Al2O3) sintered body, which have superior plasma corrosion resistance, are being used instead of conventional metal susceptors. In particular, in recent years, semiconductor manufacturing processes have been carried out in harsher environments, at temperatures between 600 and 700°C, due to process miniaturization and equipment size increases to improve yields in semiconductor processes. To withstand this environment, ceramic susceptors must meet the ceramic characteristics of having a volume resistivity of 1.0E+10 to 1.0E+13 Ω·cm at 500°C and a thermal conductivity of 30 to 60 W / mk at room temperature.

[0018] However, aluminum nitride suffers from a tendency for its volume resistivity to drop sharply at 500°C, resulting in leakage current, while alumina has a very low thermal conductivity of 20-30 W / mK at room temperature. If the thermal conductivity at room temperature is only 20-30 W / mK, temperature uniformity deviations become significant, resulting in problems such as reduced yield. Furthermore, large deviations in the temperature uniformity of thermal conductivity can result in thermal stress and thermal shock, shortening the product's lifespan. After extensive research, the present applicant has invented a ceramic susceptor that can be used at temperatures above 500°C. This ceramic susceptor has high volume resistivity, prevents leakage current, and has higher thermal conductivity at room temperature than usual, thereby solving the above problems.

[0019] The ceramic susceptor according to the first embodiment of the present invention uses a sintered body containing, as a main phase, alumina (Al2O3), which has excellent electrical insulation and high hardness, as well as stability at high temperatures, and aluminum nitride (AlN), which has excellent physical properties such as electrical insulation and thermal conductivity, and is stable at high temperatures, as a ceramic plate layer.

[0020] In particular, the present invention is characterized by the fact that by mixing alumina and aluminum nitride in an optimal ratio, it overcomes both the problems that arise when alumina and aluminum nitride are used separately and the problems that arise when alumina and aluminum nitride are not mixed in the optimal ratio. Specifically, when alumina and aluminum nitride are mixed in the optimal ratio as in the present invention, secondary phases such as AlON phase are not formed (i.e., secondary phases including AlON phase are not present). This results in a uniformly mixed and distributed alumina and aluminum nitride phase without any change in the crystalline phase, thereby maximizing the physical properties of the ceramic plate layer. Furthermore, in the process of manufacturing the ceramic plate layer, the sintering process is performed at an optimal temperature (less than 1,650°C, preferably between 1,300°C and 1,650°C) to thoroughly prevent the formation of secondary phases. As a result, the ceramic plate layer meets ceramic properties, such as a volume resistivity of 1.0E+10 to 1.0E+13 Ω·cm at 500°C and a thermal conductivity of 30 to 60 W / mk at room temperature.

[0021] The ceramic plate layer according to the first embodiment of the present invention contains more than 68 wt % and not more than 95 wt %, more preferably 70 to 80 wt %, and most preferably 73 to 77 wt % alumina.

[0022] Furthermore, the ceramic plate layer according to the first embodiment of the present invention contains 5 wt % or more but less than 32 wt %, preferably 5 to 30 wt %, more preferably 20 to 30 wt %, and most preferably 23 to 27 wt % aluminum nitride. If the alumina and aluminum nitride contents do not fall within the above ranges, the volume resistivity at 500°C and the thermal conductivity at room temperature will not meet the required ceramic properties, which are a volume resistivity of 1.0E+10 to 1.0E+13 Ω·cm at 500°C and a thermal conductivity of 30 W / mK or more at room temperature.

[0023] The purity of the alumina and aluminum nitride is preferably 99% or more, the particles thereof are preferably nano-sized, and both are preferably used in the form of powder.

[0024] More specifically, the alumina particles may have a size ranging from nanometers to micrometers. For example, the alumina particles may be obtained by mixing 3-5 μm-sized alumina particles and 50 nm-sized alumina particles in a weight ratio of approximately 7:3, followed by pulverization using a ball mill. However, the particle size and mixing ratio may vary widely, and the ball mill process may be omitted. This is not intended to limit the scope of the present invention.

[0025] The aluminum nitride particles may have an average particle size (D50) of 0.5 to 1.5 μm, preferably 0.8 to 1.3 μm, and more preferably 0.9 to 1.2 μm. If the aluminum nitride particles have an average particle size (D50) of less than 0.5 μm, the reaction temperature will be low, which may result in a reaction with alumina at low temperatures and the formation of a secondary phase. If the aluminum nitride particles have an average particle size (D50) of more than 1.5 μm, a close-packed structure with alumina may not be formed, resulting in a decrease in density during final sintering. In the present invention, it is preferable to avoid nanometer-sized aluminum nitride particles as much as possible.

[0026] Meanwhile, the ceramic plate layer according to the first embodiment may further include a dopant, if necessary, for the purpose of further improving the thermal conductivity of the ceramic plate layer.

[0027] For example, if a regular sintered body is applied to a substrate and a ceramic heater or electrostatic chuck for semiconductors is used at temperatures above 500°C, the substrate may not be able to keep up with the sudden temperature change of the heating element, resulting in fracture due to thermal shock. However, if a dopant is mixed into the substrate to improve its thermal shock resistance and it is used in a heater or electrostatic chuck, the heat from the heating element can be transferred efficiently, preventing fracture of the substrate due to thermal shock.

[0028] The dopant of the present invention may be, for example, one or more of magnesium oxide (MgO), yttria (Y2O3), graphene, and rare earth composite oxides.

[0029] If the ceramic plate layer also contains a dopant, the dopant may be present in an amount of 0.05 to 2 parts by weight, preferably 0.1 to 1 part by weight, and more preferably 0.2 to 0.8 parts by weight, based on 100 parts by weight of the total weight of the alumina and aluminum nitride. If the dopant is present in an amount less than 0.05 parts by weight, or not at all, based on 100 parts by weight of the total weight of the alumina and aluminum nitride, the same problems as those previously observed may occur, the effects of using the dopant may be significantly reduced, the improvement in thermal conductivity may be negligible, and the product may not sinter properly. Furthermore, if the dopant content exceeds 2 parts by weight based on 100 parts by weight of the total weight of the alumina and aluminum nitride, the dispersion effect may be reduced, resulting in a decrease in thermal conductivity and a decrease in sintering density. Furthermore, the dopant may cause the product to darken in color or the color of the dopant to be visible. Furthermore, it is preferable that the dopant used in the present invention has a purity of 99% or higher. Each of the dopants is preferably contained in an amount of 0.05 to 0.5% by weight.

[0030] Magnesium oxide, one of the dopants, can be included to improve the thermal conductivity and volume resistivity of the ceramic plate layer. Magnesium oxide can induce the formation of MgAl2O4 and MgAlON phases through sintering with alumina and / or aluminum nitride. However, excessive formation of MgAl2O4 and MgAlON phases can result in low density and potentially reduced thermal conductivity. Therefore, even when the same components are used, it is necessary to adjust the content of each component. For example, in the present invention, at least one of the MgAl2O4 and MgAlON phases contained in the ceramic plate layer can be present in an amount of less than 1 wt%, preferably less than 0.8 wt%, and more preferably 0.6 wt% or less, based on the total weight of the ceramic plate layer. The particle size of the magnesium oxide is not particularly limited, but nanometer-sized particles, which have a relatively weak effect, are preferably excluded.

[0031] The yttria (YO) may be included to improve the thermal conductivity of the ceramic plate layer. The purity of the yttria is preferably 99% or higher. To improve physical properties through densification, the yttria particles are preferably nano-sized, and such yttria is preferably used in the form of powder. More specifically, the average particle size (D50) of the yttria particles may be 50-150 nm, preferably 70-120 nm, and more preferably 90-100 nm. If the average particle size (D50) of the yttria particles is less than 50 nm, even a trace amount may result in a sintered body that retains the color (e.g., yellow) of the yttria particles, due to the characteristics of nano-yttria powder. Furthermore, if the average particle size (D50) of the yttria particles exceeds 150 nm, an incomplete sintered body may be formed during sintering, resulting in a decrease in density and a decrease in thermal conductivity. In particular, when the average particle size (D50) of the yttria particles is at the micrometer level, this problem may become more pronounced.

[0032] Graphene can also be included to improve the thermal conductivity of the ceramic plate layer. The purity of the graphene is preferably 99% or higher, and the graphene particles are nano-sized. Such graphene is preferably used in the form of powder (Graphene nano powder, GNP). More specifically, the average particle size (D50) of the graphene particles may be 0.1 to 1.5 nm, preferably 0.3 to 1 nm, and more preferably 0.5 to 0.8 nm. If the average particle size (D50) of the graphene particles is less than 0.1 nm, the graphene particles may not be large enough to function as bridges between graphene particles, resulting in little or no effect on improving thermal conductivity. Furthermore, if the average particle size (D50) of the graphene particles exceeds 1.5 nm, the graphene particles may become entangled with each other and be poorly dispersed, potentially resulting in a decrease in density and a decrease in thermal conductivity.

[0033] Finally, the rare earth composite oxide contains two or more rare earth metals selected from the group consisting of scandium (Sc), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (YB), and lutetium (Lu). The purity of the rare earth composite oxide containing such rare earth metals is preferably 99% or higher. The rare earth composite oxide is preferably in the form of a powder, and the size of the powder particles is not particularly limited.

[0034] The rare earth composite oxide can further improve the thermal conductivity of the ceramic plate layer and can also reduce the time required for dechucking. As described above, the rare earth composite oxide may contain two or more rare earth metals, preferably two to five different rare earth metals.

[0035] The rare earth composite oxide containing two to five different rare earth metals includes europium-gadolinium composite oxide (EuGdO X ), samarium-gadolinium composite oxide (SmGdO X ), cerium-europium composite oxide (CeEuO X ), samarium-cerium composite oxide (SmCeO X ), gadolinium-samarium composite oxide (GdSmO X ), and lanthanum-cerium composite oxide (LaCeO X ), etc., composite oxides containing two different rare earth metals; samarium-cerium-europium composite oxide (SmCeEuO X ), gadolinium-cerium-lanthanum composite oxide (GdCeLaO X ), and europium-gadolinium-samarium composite oxide (EuGdSmO X), and other composite oxides containing three different rare earth metals; samarium-cerium-gadolinium-europium composite oxide (SmCeGdEuO X ), and gadolinium-samarium-europium-lanthanum composite oxide (GdSmEuLaO X ), and other composite oxides containing four different rare earth metals; and samarium-cerium-europium-gadolinium-lanthanum composite oxide (SmCeEuGdLaO X ) and other composite oxides containing five different rare earth metals; and other oxides containing 2 to 5 different rare earth metals (oxides) can be used without any particular restrictions.

[0036] The rare earth composite oxide containing two to five different rare earth metals can contain various rare earth metals in various ratios. For example, the rare earth composite oxide containing two to five different rare earth metals can contain two rare earth metals (oxides) in a weight ratio of 2.5 to 3.5:1, three rare earth metals (oxides) in a weight ratio of 1 to 3.5:0.5 to 2.5:1, four rare earth metals (oxides) in a weight ratio of 1.5 to 3.5:0.5 to 2.5:1 to 2.5:1, or five rare earth metals (oxides) in a weight ratio of 1 to 3:0.5 to 1.5:0.5 to 1.5:1 to 2:1. The rare earth metals (oxides) can be appropriately blended to maximize the desired effect of the rare earth composite oxide. For example, SmCeEuO X The ratio of each rare earth metal (oxide) is 2:1:1, GdCeLaO X is 3:2:1, EuGdSmO X is 1.5:1.5:1, SmCeGdEuO X is 2:1:1.5:1, GdSmEuLaO X is 3:2:2:1, SmCeEuGdLaO X may be in a weight ratio of 2:1:1:1.5:1.

[0037] In the rare earth composite oxide, one rare earth metal can be dissolved in the remaining one (or any one) rare earth metal oxide. This changes the crystal structure of the rare earth metal oxide, and therefore the rare earth composite oxide may have more oxygen lattice defects than a single rare earth metal oxide. A rare earth composite oxide with increased oxygen lattice defects has improved interfacial reactivity, allowing it to react more effectively with the interface or lattice oxygen of the components in the ceramic plate layer.

[0038] In addition, rare earth metal oxides containing one rare earth metal include scandium oxide (Sc2O3), lanthanum oxide (La2O3), cerium oxide (CeO2), and praseodymium oxide (Pr6O 11 ), neodymium oxide (Nd2O3), promethium oxide (Pm2O3), samarium oxide (Sm2O3), europium oxide (Eu2O3), gadolinium oxide (Gd2O3), terbium oxide (Tb4O7), dysprosium oxide (Dy2O3), holmium oxide (Ho2O3), erbium oxide (Er2O3), thulium oxide (Tm2O3), ytterbium oxide (YB2O3), and lutetium oxide (Lu2O3), however, the present invention does not include rare earth metal oxides that contain only one rare earth metal as a dopant.

[0039] Meanwhile, in the above description, the dopant includes one or more of magnesium oxide, yttria, graphene, and rare earth metal oxides other than yttria. However, in the present invention, it is preferable that the dopant primarily includes magnesium oxide. It is also preferable that magnesium oxide and graphene are used together as the dopant. It is even more preferable that magnesium oxide, graphene, and yttria are used together as the dopant. It is most preferable that magnesium oxide, graphene, yttria, and a rare earth composite oxide are used together as the dopant.

[0040] In the event that magnesium oxide and graphene are used together as dopants, the magnesium oxide may be contained in an amount of 0.05 to 0.5 parts by weight and the graphene may be contained in an amount of 0.05 to 0.5 parts by weight, relative to 100 parts by weight of the total weight of the alumina and aluminum nitride.

[0041] Furthermore, when magnesium oxide, graphene, and yttria are used together as dopants, the magnesium oxide may be contained in an amount of 0.05 to 0.5 parts by weight, the graphene may be contained in an amount of 0.05 to 0.5 parts by weight, and the yttria may be contained in an amount of 0.05 to 0.5 parts by weight, relative to 100 parts by weight of the total weight of the alumina and aluminum nitride.

[0042] Furthermore, when magnesium oxide, graphene, yttria, and a rare earth composite oxide are used together as dopants, the magnesium oxide may be contained in an amount of 0.05 to 0.5 parts by weight, the graphene may be contained in an amount of 0.05 to 0.5 parts by weight, the yttria may be contained in an amount of 0.05 to 0.5 parts by weight, and the rare earth composite oxide may be contained in an amount of 0.05 to 0.5 parts by weight, relative to 100 parts by weight of the total weight of the alumina and aluminum nitride.

[0043] Hereinafter, the plasma-resistant hybrid coating layer formed on the ceramic plate layer of the ceramic susceptor according to the first embodiment of the present invention will be described in detail.

[0044] In the ceramic susceptor according to the first embodiment of the present invention, a coating layer is formed on the ceramic plate layer used as a sintered body, and a reaction layer is formed at the interface between the ceramic plate layer and the coating layer by reactive sintering. This reduces stress caused by differences in physical properties such as microstructure and thermal expansion coefficient between the ceramic plate layer and the coating layer, and stabilizes the coating interface.

[0045] Specifically, the ceramic susceptor according to the first embodiment of the present invention includes a coating layer located on a ceramic plate layer, and the coating layer may include a first coating layer formed on the ceramic plate layer; and a reaction layer formed at the interface between the ceramic plate layer and the first coating layer.

[0046] In conventional technology, yttria or Y-based compounds are coated on AlN or Al2O3 ceramic plates, but stress due to differences in physical properties such as microstructure and thermal expansion coefficient acts on the coating interface, causing peeling after coating. This peeling of the coating is particularly noticeable in high-temperature environments above 500°C.

[0047] However, the inventors discovered that by coating a ceramic plate containing AlN and Al2O3 with a Y (yttrium)-based compound and then forming a coating layer using a hot press sintering method, a reaction layer is formed at the interface between the ceramic plate layer and the coating layer through reaction sintering, which has the effect of increasing not only densification but also hardness and density. This reaction layer is formed by reaction sintering using high temperature and high pressure energy, and stabilizes the microstructure at the interface between the ceramic plate layer and the coating layer. It also relieves stress caused by differences in physical properties, such as the thermal expansion coefficient, between the different materials that make up the ceramic plate layer and the coating layer, allowing the coating layer to remain stable without peeling even in high-temperature environments of 500°C or more.

[0048] More specifically, in the ceramic susceptor according to the first embodiment of the present invention, a coating material including one or more of YO, YF, YOF, YAG, YAS, YAM, and YAP is sintered on the ceramic plate layer by hot pressing to form a first coating layer. At this time, a reaction layer is formed at the interface between the ceramic plate layer and the coating material through reaction sintering between the ceramic plate layer material and the coating layer material. That is, the yttrium component contained in the coating layer material may react with the aluminum or alumina component present in the ceramic plate layer to form a YAG reaction layer including one or more of YAG, YAM, and YAP, which is defined as the reaction layer in the first embodiment of the present invention.

[0049] In this case, in order to form a more stable reaction layer, it is preferable that the coating layer material essentially contains yttria (YO). However, the present invention is not limited thereto. Even if the coating material contains one or more of the Y-based compounds (YF, YOF, YAG, YAS, YAM, and YAP) other than yttria, or if two or more of the Y-based compounds including yttria are mixed, the yttrium component contained in the Y-based compound can be reactively sintered with the aluminum or alumina component present in the ceramic plate layer to form a reaction layer containing one or more of YAG, YAM, and YAP.

[0050] Accordingly, in the ceramic susceptor according to the first embodiment of the present invention, the first coating layer may include one or more of Y2O3, YF3, YOF, YAG, YAS, YAM, and YAP, and a reaction layer produced by reaction sintering is formed at the interface between the ceramic plate layer and the first coating layer, and the reaction layer may include one or more of YAG, YAM, and YAP. In this case, the first coating layer is produced by hot press sintering, and its thickness including the reaction layer may be formed to be 10 to 200 μm.

[0051] In the ceramic susceptor according to the first embodiment of the present invention, the first coating layer may contain one or more compounds selected from the group consisting of Y2O3, YF3, YOF, YAG, YAS, YAM, and YAP, which are defined as Y compounds in the present specification.

[0052] Among the Y compounds, Y2O3 stands for Yttrium Oxide and is also called yttria. YF3 stands for Yttrium Fluoride, and YOF is a YOF-based compound, including Y5O4F7, Y6O5F8, Y7O6F9, and Y 17 O 14 F 23 The YAG may refer to one or more selected from the group consisting of yttrium aluminum garnet (YAG, Yttrium Aluminum Garnet, Y3Al5O 12 ), where YAS represents yttria-alumina-silica (YAS, Yttria-Alumina-Silica or Yttrium Aluminum Silicate, Y2O3-Al2O3-SiO2), YAM represents yttrium aluminum monoclinic (YAM, Y4Al2O9), and YAP represents yttrium aluminum perovskite (YAP, YAlO3).

[0053] In the ceramic susceptor according to the first embodiment of the present invention, in order to further improve plasma resistance and particle resistance, the coating layer may be formed by forming a first coating layer and a reaction layer on the ceramic plate layer by hot pressing, and then forming a second coating layer made of a Y compound on the first coating layer.

[0054] In this case, the second coating layer may include one or more of Y2O3, YF3, YOF, YAG, YAS, YAM, and YAP and may be formed on the first coating layer by a sputtering process. That is, the second coating layer is formed by generating plasma at a relatively low vacuum, accelerating ionized inert gas such as argon (Ar) gas, and colliding it with a target including one or more of Y2O3, YF3, YOF, YAG, YAS, YAM, and YAP, thereby depositing granulated atoms including one or more of Y2O3, YF3, YOF, YAG, YAS, YAM, and YAP on the first coating layer.

[0055] The second coating layer is made of a material having the same or similar physical properties as the material constituting the first coating layer, and exhibits very high bonding strength with the first coating layer, forming an excellent bonding surface. In addition, the second coating layer has the advantage of significantly reducing the porosity of the coating layer surface, thereby further improving the plasma resistance and particle resistance by increasing the density of the coating layer.

[0056] The second coating layer as described above includes one or more of Y2O3, YF3, YOF, YAG, YAS, YAM, and YAP, and is formed on the first coating layer by a sputtering process. The thickness of the second coating layer may be 0.1 to 5 um. Of course, the second coating layer may be formed by various deposition processes other than the sputtering process.

[0057] As described above, the ceramic susceptor according to the first embodiment of the present invention is a ceramic susceptor including a ceramic plate layer and a first coating layer disposed on the ceramic plate layer, wherein the ceramic plate layer includes alumina (Al2O3) and aluminum nitride (AlN) but does not include an aluminum oxynitride phase (AlON phase), and includes a reaction layer formed by reaction sintering at the interface between the ceramic plate layer and the first coating layer. Here, the first coating layer is formed by a hot press method, and a second coating layer may be further included on the first coating layer to further improve plasma resistance and particle resistance, and the second coating layer is formed by a sputtering process.

[0058] The first coating layer is formed by placing one or more coating materials selected from Y2O3, YF3, YOF, YAG, YAS, YAM, and YAP on the ceramic plate layer and then sintering the resulting material using a hot press. The alumina or aluminum contained in the ceramic plate layer (base material) reacts with the yttrium (Y) element of the one or more coating materials selected from Y2O3, YF3, YOF, YAG, YAS, YAM, and YAP, resulting in the formation of a reaction layer at the interface between the ceramic plate layer and the first coating layer due to reactive sintering of yttrium and aluminum. The inventors of the present invention have discovered that the coating layer thus formed not only densifies the coating layer but also increases its hardness and density. The high-temperature and high-pressure energy stabilizes the microstructure at the interface between the ceramic plate and the Y compound in the coating layer.

[0059] The second coating layer may be formed on the first coating layer by a sputtering process and may contain one or more of Y2O3, YF3, YOF, YAG, YAS, YAM, and YAP. Because the second coating layer is formed on the first coating layer made of a Y compound, it can increase resistance to deformation and fracture due to the difference in physical properties between the base material and the coating layer. Furthermore, the Y compound coating can be expected to reduce particles by increasing plasma resistance.

[0060] Next, a method for manufacturing a ceramic susceptor according to the present invention will be described.

[0061] First, the method for manufacturing a ceramic susceptor according to the first embodiment includes the steps of: 1) preparing a ceramic plate layer; and 2) forming a coating layer on the ceramic plate layer.

[0062] First, the step 1) of manufacturing the ceramic plate layer includes the steps of: a) mixing alumina (Al2O3), aluminum nitride (AlN), an alcohol compound, and a binder; b) drying the mixture to manufacture a powder from which the alcohol compound component has been removed; c) compressing and molding the dried powder to manufacture a preform processed into a specific shape; d) degreasing the manufactured preform and removing the binder component; and e) sintering and polishing the degreasing preform.

[0063] If necessary, a dopant may be added and mixed in step a), and examples of the dopant include one or more of magnesium oxide (MgO), yttria (Y2O3), graphene, and rare earth composite oxides.

[0064] The alcohol compound used in step a) is used for proper mixing of the raw materials, and examples thereof include alcohol compounds having 1 to 5 carbon atoms, specifically ethanol, methanol, isopropyl alcohol, etc. Similarly, the binder used in step a) is used to improve the binding strength of the raw materials, and examples thereof include polyvinyl alcohol (PVA), polyvinyl butyral (PVB), etc.

[0065] Step b) is a step of drying the powder mixture mixed in step a) to remove the alcohol component. The drying may be performed by a method known in the art, such as spray drying or vacuum drying, and the drying time may vary depending on the physical properties of the desired ceramic plate layer.

[0066] Step c) is a step of compressing and molding the dried powder to produce a preform processed into a specific shape. The compression molding is the first molding (i.e., first molding) process for controlling the powder dried in step b) into a desired size and shape, and examples thereof include press molding. Here, cold isostatic pressing (CIP) can be further performed as needed to produce a product with a more precise specification. The press molding is preferably performed at room temperature and under normal atmospheric conditions, but is not limited thereto. The atmosphere during molding may be any as long as it does not affect the molding of the mixture. After the molding process in step c), a preform can be produced by green processing (performed before sintering, also known as green processing).

[0067] Step d) is a step of degreasing the prepared preform to remove binder components. The degreasing is a process for removing binders and oily contaminants, and can be performed at a temperature of 350 to 600°C for 60 hours or less.

[0068] Step e) is a step of sintering (secondary shaping) and polishing the degreased preform to produce a ceramic substrate. The sintering is a second shaping process (i.e., secondary shaping) to further improve the volume resistivity of the ceramic plate layer, and is preferably performed using a hot press sintering method. Furthermore, if the degreased preform is sintered at a temperature of 1,650°C or higher, alumina and aluminum nitride react to form an AlON phase, which reduces thermal conductivity. Therefore, the sintering in step e) must be performed at a temperature below 1,650°C, preferably between 1,300°C and 1,650°C.

[0069] Next, the step 2) of forming a coating layer on the ceramic plate layer includes the steps of: a) preparing a coating solution containing a plasma-resistant material; b) spraying the prepared coating solution onto the ceramic plate layer manufactured according to the step 1); and c) drying the sprayed coating solution and then hot pressing to form a first coating layer.

[0070] The plasma-resistant material in step a) is the Y compound described in the coating layer, and may include one or more of Y2O3, YF3, YOF, YAG, YAS, YAM, and YAP. The coating solution may be prepared by mixing the Y compound and a solvent such as ethanol using a mixer at a predetermined speed and time.

[0071] The spraying of the coating solution in step b) may be performed by spraying the mixed coating solution onto the ceramic plate layer using an air spray, but is not limited thereto, and any known spraying method for forming a coating layer may be used.

[0072] The drying in step c) can be performed at room temperature for 10 minutes, and the hot pressing can be performed at a temperature of 1300 to 1650°C under a pressure of 100 to 200 bar for 1 to 24 hours. Here, through the hot pressing process, as described above, a reaction layer is formed at the interface between the ceramic plate layer and the first coating layer due to reaction sintering of the yttrium component contained in the first coating layer and the aluminum or alumina component contained on the ceramic plate layer.

[0073] In addition, after step c), in order to further improve the plasma resistance and particle resistance of the coating layer, step e) may further include a step of forming a second coating layer by coating the plasma resistant material on the first coating layer. The coating method of step e) may be any method capable of coating the plasma resistant material, and is preferably performed by spraying or sputtering.

[0074] The ceramic susceptor of the present invention manufactured by the above manufacturing method can be applied to various devices or components for semiconductor manufacturing processes, and is preferably used as a material for heaters and electrostatic chucks for semiconductor manufacturing processes. However, there is no particular limitation on the field of application, and it can also be used in fields where ceramic materials are used in high-temperature plasma environments.

[0075] The present invention will be described in more detail below with reference to specific examples. The following examples are provided to illustrate the present invention, but the present invention is not limited to the following examples.

[0076] [Manufacturing Examples 1 to 7] Fabrication of ceramic plate layers and evaluation of their properties To find the optimal mixing ratio of alumina and aluminum nitride, the raw materials were mixed in the ratios shown in Table 1 below, and then small amounts of ethanol and polyvinyl butyral (binder) were added and dried. The dried mixture was then press-molded and processed to produce a preform, which was then degreased at a temperature of 500°C for 30 hours and sintered in a high-temperature pressure sintering furnace (pressure of 250 bar, temperature of 1,630°C) and polished to produce a ceramic plate layer.

[0077] The volume resistivity, thermal conductivity, etc. of each manufactured ceramic susceptor were then measured. Specifically, a voltage of 500 V / mm was applied to the ceramic susceptor, and the current was measured (measured in a vacuum atmosphere and at room temperature) one minute after application, and the volume resistivity was calculated. Furthermore, using a NETZSCH LFA 467 device, test specimens were prepared according to the ASTM C0408-88R11 standard, and measurements were then taken at room temperature to calculate the thermal conductivity. The results are shown in Table 2 below.

[0078] [Table 1]

[0079] [Table 2]

[0080] As can be seen from Tables 1 and 2, the ratio of aluminum nitride phase varies depending on the ratio of aluminum nitride added, and accordingly, the volume resistance at high temperature and the thermal conductivity at room temperature vary.

[0081] More specifically, the changes in physical properties depending on the ratio of aluminum nitride added were confirmed, and the results of XRD showed that no AlON phase was formed in any of the final products of Production Examples 1 to 7. Furthermore, it was shown that Production Examples 3 to 5 complied with the volume resistivity and thermal conductivity, and Production Example 5, in which alumina and aluminum nitride were mixed in a weight ratio of 75:25, was shown to be the best overall.

[0082] Therefore, if the aluminum nitride content is too low, Al2O3 phase is formed as the main phase, and there is almost no effect in improving thermal conductivity, and if the aluminum nitride content is too high, the proportion of AlN phase becomes high, and there is an effect in improving thermal conductivity, but volume resistivity and hardness tend to decrease.

[0083] [Manufacturing Examples 5-1 to 5-5] Evaluation of the physical properties of ceramic plate layers depending on sintering temperature Based on the results that Preparation Example 5, in which alumina and aluminum nitride were mixed in a weight ratio of 75:25, was shown to be the best overall, ceramic plate layers were manufactured by varying only the sintering temperature as shown in Table 3 below (the manufacturing method was the same as Preparation Example 1 except for the composition and sintering temperature).

[0084] The volume resistivity and thermal conductivity of each ceramic plate layer were then measured. Specifically, a voltage of 500 V / mm was applied to the ceramic susceptor, and the current was measured (measured in a vacuum atmosphere and at room temperature) one minute later to calculate the volume resistivity. Additionally, test specimens were prepared according to ASTM C0408-88R11 using a NETZSCH LFA 467 device, and then measured at room temperature to calculate the thermal conductivity. The results are shown in Table 4 below.

[0085] [Table 3]

[0086] [Table 4]

[0087] Alumina reacts with aluminum nitride above a certain temperature to form an AlON phase. Even though the AlON phase has high electrical insulation properties, its thermal conductivity is low, so the presence or absence of the AlON phase significantly affects physical properties. Figure 1 is an XRD graph showing the physical properties of ceramic susceptors as a function of sintering temperature, and Figure 2 is a graph showing the correlation between alumina content and sintering temperature. Referring to Figures 1 and 2, at a sintering temperature of 1,500°C, undersintering occurred, making it impossible to measure volume resistivity, and the measured thermal conductivity and density were very low. Analysis of the XRD graphs showed that an AlON phase was formed at sintering temperatures above 1,650°C. As the AlON content increased, the volume resistivity increased, but the thermal conductivity decreased sharply. Therefore, it can be concluded that sintering in the present invention is preferably performed at temperatures below 1,650°C.

[0088] [Production Examples 8 to 19, Comparative Production Examples 8 to 19] Ceramic plate layer manufacturing Considering the experimental results of Preparation Example 5-3, raw materials were mixed according to the composition in Table 5 below, and trace amounts of ethanol and polyvinyl butyral (binder) were further mixed and then dried. The dried mixture was then press-molded and processed to produce a preform, which was then degreased at a temperature of 500°C for 30 hours, and the degreased preform was sintered in a high-temperature pressure sintering furnace (pressure of 250 bar, temperature of 1,630°C) and polished to produce a ceramic plate layer.

[0089] [Table 5]

[0090] [Experimental Example 1] Evaluation of volume resistivity and thermal conductivity of ceramic susceptors. A voltage of 500 V / mm was applied to each of the ceramic susceptors manufactured in Manufacturing Examples 8 to 19 and Comparative Manufacturing Examples 8 to 19, and then the current was measured (measured in a vacuum atmosphere and at room temperature) after 1 minute to calculate the volume resistivity. The results are shown in Table 6 below.

[0091] In addition, specimens were prepared from each of the ceramic plate layers prepared in Preparation Examples 8 to 19 and Comparative Preparation Examples 8 to 19 according to ASTM C0408-88R11 using a NETZSCH LFA 467 device, and the thermal conductivity was calculated by measuring the specimens at room temperature. The results are also shown in Table 6 below.

[0092] Furthermore, the density of each of the ceramic plate layers manufactured in Manufacturing Examples 8 to 19 and Comparative Manufacturing Examples 8 to 19 was calculated using Archimedes' method, and the results are also shown in Table 6 below.

[0093] [Table 6]

[0094] The volume resistivity and thermal conductivity of each of the ceramic plate layers manufactured in Manufacturing Examples 8 to 19 and Comparative Manufacturing Examples 8 to 19 were measured. As a result, as shown in Table 6, all of the ceramic plate layers of Manufacturing Examples 8 to 19 satisfied the volume resistivity at 500°C (1.0E+10 Ω·cm to 1.0E+13 Ω·cm) required by the next-generation semiconductor manufacturing process.

[0095] In addition, in terms of thermal conductivity, as can be seen from the comparison of Preparation Examples 8 to 10 and Comparative Preparation Examples 8 to 10, the comparison of Preparation Examples 11 to 13 and Comparative Preparation Examples 11 to 13, the comparison of Preparation Examples 14 to 16 and Comparative Preparation Examples 14 to 16, and the comparison of Preparation Examples 17 to 19 and Comparative Preparation Examples 17 to 19, it was shown that Preparation Examples 8 to 19, which used each dopant at a content of 0.05 to 0.5 wt%, were superior to Comparative Preparation Examples 8 to 19, which used more than 0.05 to 0.5 wt% of even one dopant.

[0096] On the other hand, when graphene nanopowder (GNP) was added as a dopant in addition to MgO, the effect was negligible when the GNP content was less than 0.05 wt%, but the thermal conductivity improved when the GNP content was 0.05-0.5 wt%. However, when the GNP content exceeded 0.5 wt%, the volume resistivity, density, and hardness tended to decrease sharply.

[0097] In addition, when nano-sized yttria (Y2O3) was added as a dopant in addition to MgO and GNP at a concentration of 0.05-0.5 wt%, it also showed the effect of improving sinterability and increasing volume resistance and thermal conductivity. However, when yttria was used at a concentration exceeding 0.5 wt%, it reacted with alumina to form large amounts of secondary phases such as YAP, YAM, and YAG, which tended to reduce thermal conductivity.

[0098] In addition, when rare earth composite oxides were added as dopants in addition to MgO, GNP, and Nano YO3, when used in amounts of 0.05-0.5 wt%, not only did volume resistivity and thermal conductivity tend to increase, but density and hardness also increased. On the other hand, when the rare earth composite oxide was used in amounts exceeding 0.5 wt%, both volume resistivity and thermal conductivity tended to decrease sharply.

[0099] Furthermore, comparing Preparation Example 9 and Comparative Preparation Example 9, Preparation Example 9 used 0.5 wt% MgO, while Comparative Preparation Example 9 used 1 wt% MgO. Although there was no significant difference in the contents, thermal conductivity dropped sharply as the MgO content increased from 0.5 wt% to 1 wt%. This is because when the MgO content exceeds 0.5 wt%, the MgAl2O4 phase or MgAlON phase is formed in excess of 0.6 wt% in the final product, increasing its fraction. These results can be seen in Table 7 below.

[0100] [Table 7]

[0101] [Examples 1 to 5, Comparative Examples 1 to 6] Ceramic susceptor manufacturing A ceramic susceptor was manufactured as shown in Table 8 below.

[0102] In Examples 1 to 5 and Comparative Examples 3 and 6, the ceramic plate layer previously produced in Production Example 18 in Table 5 was used as the ceramic plate layer.

[0103] In the case of Comparative Examples 1 to 2 and Comparative Examples 4 to 5, a ceramic plate layer was manufactured using a single material listed in Table 8 below in the same manner as in Preparation Example 18 of Table 5, and then the ceramic plate layer was used as a ceramic susceptor without a separate coating layer.

[0104] In Comparative Example 6 and Examples 1 to 5, a coating layer was formed on the ceramic plate layer previously prepared in Preparation Example 18 of Table 5 in the following manner to prepare a ceramic susceptor.

[0105] [Table 8]

[0106] First, the first coating layer of Comparative Example 6 was formed by a suspension plasma spray (SPS) or aerosol deposition (AD) process, and yttria (Y2O3) was used as the material for the coating layer.

[0107] The suspension plasma spray coating and aerosol deposition coating methods are well-known techniques for coating ceramic materials, and detailed descriptions are omitted. However, in the first coating layer formation process of Comparative Example 6, sandblasting was performed on the surface of the ceramic plate layer to improve adhesion of the coating powder (Y2O3 powder in this comparative example), and the ceramic plate layer was preheated 2-3 times at temperatures between 70°C and 100°C to reduce thermal stress during the process. In addition, the plasma source gas used was Ar:He = 70:30, and the current applied between the positive and negative electrodes was set to 500 A.

[0108] For the first coating layer in Example 1, a solution of Y2O3 and ethanol in a weight ratio of 40:60 was mixed in a Thinky ARE-501 mixer at 1200 rpm for 1 hour to prepare a coating solution. The mixed coating solution was sprayed onto the ceramic plate using an air sprayer, dried at room temperature for 10 minutes, and then hot-pressed at 1630°C and 200 bar pressure. As a result, a coating layer with a thickness of 100 μm to 300 μm before hot-pressing and a thickness of 120 μm including the reaction layer after hot-pressing was formed.

[0109] For the first coating layer of Example 2, a primary coating solution was prepared by mixing Y2O3 and ethanol in a weight ratio of 40:60 in a Thinky ARE-501 mixer at 1200 rpm for 30 minutes. A secondary solution of YAG and ethanol in a weight ratio of 58:42 was then mixed with the primary coating solution to achieve a weight ratio of Y2O3:YAG = 50:50. This and the primary coating solution were then mixed in the same mixer at 1200 rpm for 30 minutes to produce a final coating solution with a weight ratio of Y2O3:YAG = 50:50. The resulting coating solution was sprayed onto the ceramic plate using an air sprayer, dried at room temperature for 10 minutes, and then hot-pressed at 1630°C and 200 bar. Before hot-pressing, a coating layer between 100 and 300 μm thick was formed. After hot-pressing, a coating layer with a thickness of 120 μm, including the reaction layer, was formed.

[0110] For the first coating layer of Example 3, a primary coating solution was prepared by mixing Y2O3 and ethanol in a weight ratio of 40:60 in a Thinky ARE-501 mixer at 1200 rpm for 30 minutes. A secondary solution of YAG and ethanol in a weight ratio of 58:42 was then mixed with the primary coating solution to achieve a weight ratio of Y2O3:YAG of 45:55. This was then mixed with the primary coating solution in the same mixer at 1200 rpm for 30 minutes to produce a final coating solution with a weight ratio of Y2O3:YAG of 45:55. The resulting coating solution was sprayed onto the ceramic plate using an air sprayer, dried at room temperature for 10 minutes, and then hot-pressed at 1630°C and 200 bar. Before hot-pressing, a coating layer between 100 and 300 μm thick was formed. After hot-pressing, a coating layer of 120 μm thick, including a reaction layer, was formed.

[0111] For the first coating layer of Example 4, a primary coating solution was prepared by mixing Y2O3 and ethanol in a weight ratio of 40:60 in a Thinky ARE-501 mixer at 1200 rpm for 30 minutes. A secondary solution of YAG and ethanol in a weight ratio of 58:42 was then mixed with the primary coating solution to achieve a Y2O3:YAG weight ratio of 40:60. This was then mixed with the primary coating solution in the same mixer at 1200 rpm for 30 minutes to produce a final coating solution with a Y2O3:YAG weight ratio of 40:60. The resulting coating solution was sprayed onto the ceramic plate using an air sprayer, dried at room temperature for 10 minutes, and then hot-pressed at 1630°C and 200 bar. Before hot-pressing, a coating layer between 100 and 300 μm thick was formed. After hot-pressing, a coating layer of 120 μm thick, including a reaction layer, was formed.

[0112] The first coating layer of Example 5 was prepared by mixing a 40:60 weight ratio of Y2O3 and ethanol in a Thinky ARE-501 mixer at 1200 rpm for 1 hour. The mixed coating solution was sprayed onto a ceramic plate using an air sprayer, dried at room temperature for 10 minutes, and then hot-pressed at 1630°C and 200 bar. The resulting coating layer was 100-300 μm thick before hot-pressing and 120 μm thick after hot-pressing, including the reaction layer. The ceramic susceptor with the first coating layer was then placed in a vacuum chamber equipped with an RF electrode. Argon (Ar) gas, an inert gas, was injected, and a sputtering process was performed using yttrium fluoride (YF3) as the target material to form a 1-3 μm thick second coating layer of YF3 on the first coating layer.

[0113] [Experimental Example 2] Peeling test of ceramic susceptor coating layer The ceramic susceptors manufactured according to Comparative Example 6, Example 1, and Example 5 were subjected to heat treatment at 500°C, which is the actual operating temperature, to test whether the coating layer peeled off at high temperatures. Photographs of the surface of the ceramic susceptor after coating and scanning electron microscope (SEM) images of the cross section of the bonding surface before and after the heat treatment are shown in FIGS. 3 to 5.

[0114] First, referring to FIG. 3, the ceramic susceptor manufactured according to Comparative Example 6 has an yttria coating layer (first coating layer) formed on the ceramic plate layer manufactured according to the first embodiment of the present invention by a conventional ceramic coating method such as suspension plasma spraying or aerosol deposition. A stable coating layer appears to have been formed on the surface photograph before the 500°C heat treatment. However, an SEM image of the bonding surface shows that the bonding surface is irregular and that numerous pores have been formed. Therefore, when the ceramic susceptor is subjected to a 500°C heat treatment, peeling of the coating layer occurs, cracks occur, and it is confirmed that the ceramic susceptor cannot be used in a high-temperature environment of 500°C, which is the actual operating temperature.

[0115] 4, the ceramic susceptor manufactured in Example 1 according to the present invention has a stable coating layer formed in the surface photograph and SEM image before heat treatment at 500°C, and a reaction layer formed at the interface between the first coating layer and the ceramic plate layer, forming a dense bonded structure. Even after heat treatment at 500°C, the surface photograph and SEM image show that the stable coating layer remains, and the reaction layer formed at the interface between the first coating layer and the ceramic plate layer also maintains a dense bonded structure. This confirms that the coating layer does not peel off even in a high-temperature environment of 500°C, which is the actual operating temperature, and that plasma resistance and particle resistance can be improved.

[0116] Finally, referring to Figure 5, the ceramic susceptor manufactured in accordance with the present invention according to Example 5, like the ceramic susceptor manufactured in accordance with Example 1 shown in Figure 4, shows that a stable coating layer is formed and maintained in both surface photographs and SEM images before and after heat treatment at 500°C, confirming a dense bond structure due to the formation of a reaction layer. Furthermore, in the case of Example 5, a second coating layer of YF3 is formed by a sputtering process on a first coating layer formed by hot pressing, and this also forms a uniform and stable bonding surface. It can be seen that forming an additional coating layer of the Y compound on the first coating layer using various conventional coating processes can be used in a variety of ways to form a coating layer that can further improve plasma resistance and particle resistance without peeling off the coating layer even in high-temperature environments above 500°C.

[0117] [Experimental Example 3] Plasma resistance test of ceramic susceptors The manufactured ceramic susceptor was subjected to a plasma resistance test at 20° C. The plasma resistance test was carried out under the conditions shown in Table 9 below.

[0118] [Table 9]

[0119] The results of the plasma resistance test at 20° C. can be seen in Table 10 below.

[0120] [Table 10]

[0121] In the case of Comparative Examples 1 to 5 shown in Table 10, the results of the plasma resistance test are shown for ceramic susceptors made of bulk ceramic plate layers without forming a coating layer.

[0122] The ceramic susceptors of Comparative Examples 1 and 2, which are manufactured from AlN and Al2O3 bulk materials, which are most commonly used as conventional ceramic susceptors, exhibit good plasma resistance compared to susceptors made from conventional metal materials. However, it was confirmed that the plasma resistance is significantly lower than that of the ceramic susceptors of Comparative Examples 4 and 5, which are manufactured from Y2O3 and YAG bulk materials, which are used in various fields as plasma-resistant materials. The ceramic susceptor of Comparative Example 3, which is made from a ceramic plate layer manufactured by Manufacturing Example 18 of the first embodiment of the present invention, also exhibits plasma resistance characteristics that are not significantly different from those of Comparative Examples 1 and 2.

[0123] However, in recent years, semiconductor manufacturing processes that use high-power plasma and are carried out in high-temperature environments of 500°C or higher require higher plasma resistance and particle resistance, and plasma resistance equivalent to the level of the Y2O3 and YAG bulk materials shown in Comparative Examples 4 and 5 is required. However, in the case of the Y2O3 and YAG materials, since they are made of expensive rare earth elements, it is difficult to form sintered bodies with complex shapes and they do not satisfy the physical properties required for ceramic susceptors, such as volume resistance and thermal conductivity, making them difficult to use as bulk materials. As a result, they are currently mainly used as coating layers, as shown in Comparative Example 6.

[0124] In Comparative Example 6, a Y2O3 coating layer was formed on a ceramic plate manufactured by Manufacturing Example 18 of the first embodiment of the present invention using a conventional Suspension Plasma Spray (SPS) or Aerosol Deposition (AD) process. This comparative example exhibited high plasma resistance similar to that of the ceramic susceptors manufactured from bulk materials Y2O3 and YAG shown in Comparative Examples 4 and 5. However, as shown in Experimental Example 2 above, peeling of the coating layer occurred in high-temperature environments above 500°C, which is the actual operating temperature, and therefore the comparative example could not be used in high-temperature environments.

[0125] In contrast, the ceramic susceptors of Examples 1 to 5 manufactured according to the first embodiment of the present invention not only exhibit plasma resistance equivalent to or higher than that of ceramic susceptors manufactured using bulk materials such as Y2O3 or YAG as shown in Table 10, but also exhibit relatively low porosity as shown in Experimental Example 2 and FIG. 6 described above. Furthermore, the reaction layer formed at the interface between the ceramic plate layer and the first coating layer not only forms a uniform and stable bonding surface but also exhibits a dense bonding structure. Therefore, even in a high-temperature environment of 500°C, there is no peeling of the coating layer, and it can be confirmed that the ceramic susceptors have excellent plasma resistance and a particle reduction effect due to this.

[0126] In particular, the plasma resistance test results of Examples 2 to 4, in which Y2O3 and YAG were mixed in a certain ratio when forming the first coating layer, were shown to be superior to the plasma resistance test result of Example 1, in which the first coating layer was formed using only Y2O3 alone. Therefore, it may be preferable to use a mixture of two or more of the Y compounds (Y2O3, YF3, YOF, YAG, YAS, YAM, and YAP) when forming the first coating layer.

[0127] Furthermore, in Example 5, in which a second coating layer was additionally formed by a sputtering process on a first coating layer formed by hot press sintering, the results of the porosity and plasma resistance tests were shown to be the best. According to the present invention, a first coating layer of a Y compound is formed by hot pressing, and a reaction layer is formed at the interface between the ceramic plate layer and the first coating layer by reactive sintering, thereby ensuring a stable bonding surface and a dense bonding structure. It may be more preferable to form a second coating layer of the Y compound on the first coating layer through various conventional deposition processes, such as sputtering, thereby further reducing the porosity of the coating layer surface and improving plasma resistance.

[0128] As described above, the ceramic susceptor according to the present invention is a ceramic susceptor including a ceramic plate layer and a first coating layer located on the ceramic plate layer, wherein the ceramic plate layer includes alumina (Al2O3) and aluminum nitride (AlN) but does not include an aluminum oxynitride phase (AlON phase), and includes a reaction layer formed by reactive sintering at the interface between the ceramic plate layer and the first coating layer. Here, the first coating layer is formed by a hot press method, and a second coating layer may be further included on the first coating layer to further improve plasma resistance and particle resistance. The second coating layer is formed by a sputtering process, and has ceramic properties such as a volume resistivity of 1.0E+10 to 1.0E+13 Ω·cm at 500°C and a thermal conductivity of 30 to 60 W / mk or more at room temperature. In addition, the coating layer does not peel off even during a high-temperature process at 500°C, and has the advantages of having plasma resistance and particle reduction effects equivalent to or better than those of Y2O3 or YAG bulk materials.

Claims

1. A ceramic susceptor including: a ceramic plate layer; and a coating layer disposed on the ceramic plate layer; The ceramic plate layer is made of alumina (Al ２ O ３ ) and aluminum nitride (AlN); Does not contain an aluminum oxynitride phase (AlON phase), a reaction layer formed at the interface between the ceramic plate layer and the coating layer.

2. The coating layer is Y ２ O ３ , Y.F. ３ , YOF, YAG, YAS, YAM, and YAP, The ceramic susceptor according to claim 1 , wherein the reaction layer includes at least one of YAG, YAM, and YAP.

3. The coating layer is formed on the ceramic plate layer by hot pressing, The ceramic susceptor according to claim 1 , wherein the reaction layer is formed by reactive sintering of components contained in the ceramic plate layer and the coating layer.

4. The coating layer is a first coating layer disposed on the ceramic plate layer; a second coating layer overlying the first coating layer; and a reaction layer formed at the interface between the first coating layer and the ceramic plate layer; The first coating layer and the second coating layer are ２ O ３ , Y.F. ３ , YOF, YAG, YAS, YAM, and YAP, The ceramic susceptor according to claim 1 , wherein the reaction layer includes at least one of YAG, YAM, and YAP.

5. The first coating layer is formed on the ceramic plate layer by hot pressing, The second coating layer is formed on the first coating layer by sputtering, The ceramic susceptor according to claim 4, wherein the reaction layer is formed by reactive sintering of components contained in the ceramic plate layer and the first coating layer.

6. The alumina content is more than 68 wt % and not more than 95 wt %; The ceramic susceptor according to claim 1, wherein the content of the aluminum nitride is 5% by weight or more and less than 32% by weight.

7. 2. The ceramic susceptor according to claim 1, wherein the ceramic susceptor has a volume resistivity of 1.0E+10 to 1.0E+13 Ω cm at 500° C. and a thermal conductivity of 30 to 60 W / m.k at room temperature.

8. The ceramic plate layer is made of magnesium oxide (MgO), yttria (Y ２ O ３ 2. The ceramic susceptor according to claim 1, further comprising at least one dopant selected from the group consisting of graphene and rare earth composite oxides.

9. 9. The ceramic susceptor according to claim 8, wherein the dopant is contained in an amount of 0.05 to 2 parts by weight based on 100 parts by weight of the total weight of the alumina and aluminum nitride.

10. the dopant comprises magnesium oxide and graphene; 9. The ceramic susceptor according to claim 8, wherein the magnesium oxide is contained in an amount of 0.05 to 0.5 parts by weight and the graphene is contained in an amount of 0.05 to 0.5 parts by weight, based on 100 parts by weight of the total weight of the alumina and aluminum nitride.

11. the dopant comprises magnesium oxide, graphene, and yttria; 9. The ceramic susceptor according to claim 8, wherein the magnesium oxide is contained in an amount of 0.05 to 0.5 parts by weight, the graphene is contained in an amount of 0.05 to 0.5 parts by weight, and the yttria is contained in an amount of 0.05 to 0.5 parts by weight, relative to 100 parts by weight of a total weight of the alumina and aluminum nitride.

12. the dopant includes magnesium oxide, graphene, yttria, and a rare earth composite oxide; 9. The ceramic susceptor according to claim 8, wherein the magnesium oxide is contained in an amount of 0.05 to 0.5 parts by weight, the graphene is contained in an amount of 0.05 to 0.5 parts by weight, the yttria is contained in an amount of 0.05 to 0.5 parts by weight, and the rare earth composite oxide is contained in an amount of 0.05 to 0.5 parts by weight, relative to 100 parts by weight of a total weight of the alumina and aluminum nitride.

13. 9. The ceramic susceptor according to claim 8, wherein the ceramic plate layer has a volume resistivity of 1.0E+10 to 1.0E+13 Ω cm at 500° C. and a thermal conductivity of 30 to 60 W / m.k at room temperature.

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