Ceramic susceptor including core / shell structured material as coating layer

Abstract

In particular, disclosed is a ceramic susceptor including a core / shell structure material as a coating layer, in which a ceramic sintered base material having excellent volume resistance at high temperature and thermal conductivity at room temperature is coated with a core / shell structure material including a material similar to or the same as the base material while having various physical advantages such as plasma resistance and durability, whereby plasma resistance, durability, and particle resistance as well as volume resistance and thermal conductivity are improved. The ceramic susceptor comprises: a ceramic plate layer; and a coating layer disposed on the ceramic plate layer and formed by sintering a core / shell structure material, wherein the ceramic plate layer includes alumina (Al2O3) and aluminum nitride (AlN), does not include a secondary phase of an aluminum oxynitride phase (AlON phase), and the coating layer has a structure in which particle phases constituting a shell form a continuous phase along a grain boundary of core particle phases.

Description

Ceramic susceptor comprising core / shell structural material as a coating layer

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0084433, filed June 27, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a ceramic susceptor comprising a core / shell structure material as a coating layer, and more particularly, to a ceramic susceptor comprising a core / shell structure material as a coating layer, which has various advantages in terms of physical properties such as plasma resistance and durability, and which includes a material similar to or identical to the base material, on a ceramic sintered body base material having excellent volume resistivity at high temperatures and thermal conductivity at room temperature, thereby improving not only volume resistivity and thermal conductivity but also plasma resistance, durability, and particle resistance.

[0003] Recent semiconductor processes have evolved toward miniaturization and high integration for yield improvement, as well as toward larger equipment diameters. This necessitates the use of high-power plasma, and processes are performed in harsh, high-temperature environments. Vacuum plasma equipment utilizing high-temperature plasma is widely used in the field of semiconductor device etching or other processes for implementing ultra-fine shapes. Examples of such vacuum plasma equipment include PECVD (plasma enhanced chemical vapor deposition) equipment, which forms a deposition film on a substrate using a chemical vapor deposition method using plasma; sputtering equipment, which forms a deposition film using a physical method; and dry etching equipment, which etches a substrate or a material coated on the substrate into a specific pattern.

[0004] Because high-temperature plasma is generated inside these vacuum plasma equipment, the chamber and the components inside it are bound to be damaged. Furthermore, there is a high possibility that certain elements and contaminant particles are 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 equipment, reactive gases such as F and Cl are injected under a plasma atmosphere, so the inner walls of the chamber and its internal components cannot help but be exposed to a very severe corrosive environment. Typically, this corrosion primarily causes chemical and physical damage to the chamber and the components inside it, and secondarily, the generation of contaminants and particles causes an increase in the defect rate and a decrease in the quality of products manufactured through the process inside the chamber.

[0005] Furthermore, if the chamber and its internal components are damaged, additional costs are incurred due to the need to replace, clean, or repair parts of the damaged equipment, and the process line must be stopped for this purpose, which also increases the process time required for product manufacturing. For this reason, the metal susceptors installed inside the existing chambers are being replaced with ceramic susceptors. Examples of such ceramic susceptors include sintered aluminum nitride (AlN) bodies or sintered alumina (Al2O3) bodies, which have excellent thermal conductivity. These ceramic susceptors are mainly used in heaters and electrostatic chucks for semiconductor manufacturing processes.

[0006] Aluminum nitride is stable at high temperatures and possesses excellent physical properties, including electrical insulation and thermal conductivity. Furthermore, because it has a coefficient of thermal expansion similar to silicon, it is primarily used in semiconductor manufacturing equipment that requires high electrical resistance at high temperatures. Alumina is also a high-temperature stable material, boasting superior electrical insulation and high hardness compared to aluminum nitride.

[0007] However, even in the case of these recent ceramic susceptors, they do not satisfy the ceramic properties such as volume resistivity and thermal conductivity to withstand the harsh high-temperature process environment. In the case of aluminum nitride, the volume resistivity decreases rapidly at 500℃, which tends to generate leakage current, and in the case of alumina, there is a problem that the thermal conductivity at room temperature is very low at the level of 20 to 30 W / m·K. If the thermal conductivity at room temperature is only 20 to 30 W / m·K, problems such as large temperature uniformity deviation and reduced yield occur. In addition, if the temperature uniformity deviation of thermal conductivity is large, the life of the product may be shortened due to thermal stress and thermal shock.

[0008] In addition, even when using ceramic parts such as sintered aluminum nitride or sintered alumina, not only is the corrosion resistance still reduced by plasma, but there is also the problem of contaminant particles being generated from the surface of the part due to halogen gases (F, Cl, Br, I, etc.). Therefore, in the art, there have been attempts to improve plasma corrosion resistance by coating the surface of the ceramic part with fluorine-based substances such as YOF, AlF, LaF, YF3, or yttria (Y2O3) that have plasma corrosion resistance through methods such as plasma spray coating, aerosol deposition, PVD, or CVD. However, in this case, the relative density is low, so that the coating layer peels off from the base material or pores are formed in the coating layer, which not only reduces the plasma corrosion resistance, but also causes the powder that makes up the coating layer to be lost, generating fine particles and increasing the process cost.

[0009] To solve this problem, YAG (Yttrium Aluminum Garnet, Y3Al5O) is a ceramic material that is a compound of yttria and alumina and has high thermal stability, creep resistance, optical properties, and plasma resistance.12 ) as a coating material. However, the development of such coating materials alone has problems such as the formation of pores or cracks at the bonding interface between the base material and the coating layer, which causes the coating layer to peel off or be damaged, due to the difficulty in forming a dense bond due to the difference in physical properties and thermal characteristics between the base material and the coating material.

[0010] Therefore, in recent semiconductor processes using high-temperature environments and high-power plasmas, there is a need to develop a novel ceramic material that has excellent volume resistivity and thermal conductivity, and has plasma corrosion resistance on the surface of the ceramic material, but is coated in a manner that prevents the coating layer from peeling off from the base material, does not generate fine particles, and enables dense bonding of the base material and the coating layer, thereby possessing excellent plasma resistance and durability.

[0011] Accordingly, the purpose of the present invention is to provide a ceramic susceptor having improved volume resistivity and thermal conductivity as well as plasma resistance, durability, and particle resistance by coating a core / shell structure material having various physical properties such as plasma resistance and durability on a ceramic sintered body base material having excellent volume resistivity at high temperatures and thermal conductivity at room temperature, and including a material similar to or identical to the base material.

[0012] In order to achieve the above object, the present invention provides a ceramic susceptor comprising: a ceramic plate layer; and a coating layer positioned on the ceramic plate layer and formed by sintering a core / shell structural material; wherein the ceramic plate layer includes alumina (Al2O3) and aluminum nitride (AlN) and does not include a secondary phase of an aluminum oxynitride phase (AlON phase), and the coating layer has a structure in which particle phases constituting a shell form a continuous phase along an interface (grain boundary) of core particle phases.

[0013] According to the ceramic susceptor comprising a core / shell structure material according to the present invention as a coating layer, by coating a core / shell structure material comprising a material similar or identical to the base material, which has various advantages in terms of physical properties such as plasma resistance and durability, on a ceramic sintered body base material having excellent volume resistivity at high temperatures and thermal conductivity at room temperature, it has the advantage of improving not only volume resistivity and thermal conductivity but also plasma resistance, durability, and particle resistance.

[0014] FIG. 1 is a cross-sectional view of a core / shell structure material particle included in a ceramic susceptor of the present invention.

[0015] Figure 2 is a cross-sectional view schematically illustrating the internal structure of a coating layer formed by sintering a core / shell structure material included in a ceramic susceptor of the present invention.

[0016] Figure 3 is an XRD graph showing the physical properties of a ceramic susceptor according to sintering temperature.

[0017] Figure 4 is a graph showing the correlation between alumina content and sintering temperature.

[0018] FIG. 5 is an XRD graph of a coating layer of a ceramic susceptor according to one embodiment of the present invention.

[0019] Figure 6 is an XRD graph for a typical ceramic susceptor.

[0020] Figure 7 is an image of a coating layer of a ceramic susceptor according to one embodiment of the present invention observed using a transmission electron microscope (TEM).

[0021] Figure 8 is an image of a cross-section of a ceramic susceptor according to one embodiment of the present invention observed using a scanning electron microscope (SEM).

[0022] Figure 9 is an image of a cross-section of a coating layer of a ceramic susceptor according to one embodiment of the present invention observed using a scanning electron microscope (SEM).

[0023] Figure 10 is an image of a cross-section of a typical ceramic susceptor observed using a scanning electron microscope.

[0024] FIG. 11 is an image of a cross-section of a surface where a ceramic plate layer and a core / shell coating layer are bonded in a ceramic susceptor according to one embodiment of the present invention, observed using a scanning electron microscope (SEM, 800x magnification).

[0025] FIG. 12 is an image of a cross-section of a surface where a ceramic plate layer and a core / shell coating layer are bonded in a ceramic susceptor according to one embodiment of the present invention, observed using a scanning electron microscope (SEM, 2,000x magnification).

[0026] Hereinafter, the present invention will be described in detail.

[0027] A ceramic susceptor according to the present invention comprises a ceramic plate layer and a coating layer formed by sintering a core / shell structural material, positioned on the ceramic plate layer, wherein the ceramic plate layer comprises alumina (Al2O3) and aluminum nitride (AlN) and does not include a secondary phase of an aluminum oxynitride phase (AlON phase), and the coating layer is characterized in that it has a structure in which particle phases constituting a shell form a continuous phase along an interface (grain boundary) of core particle phases.

[0028] Additionally, a separate coating layer containing the same or different components as the coating layer may be positioned on the coating layer.

[0029] As semiconductor processes become increasingly miniaturized and highly integrated, the use of high-power plasma is inevitable. Accordingly, vacuum plasma equipment that utilizes high-temperature plasma is widely used for etching semiconductor devices or implementing other ultra-fine shapes. Accordingly, the industry is using ceramic susceptors made of aluminum nitride (AlN) sintered bodies or alumina (Al2O3) sintered bodies, which have superior plasma corrosion resistance, instead of existing metal susceptors. In particular, recently, semiconductor manufacturing processes are being performed in harsher environments, such as 600 to 700°C, to improve yields in semiconductor processes by miniaturizing processes and increasing the diameter of equipment. To withstand this environment, the ceramic susceptor must satisfy the ceramic characteristics of 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 or higher at room temperature.

[0030] However, in the case of aluminum nitride, the volume resistivity decreases rapidly at 500℃, which tends to generate leakage current, and in the case of alumina, there is a problem that the thermal conductivity at room temperature is very low at the level of 20 to 30 W / m·K. If the thermal conductivity at room temperature is only 20 to 30 W / m·K, problems such as large temperature uniformity deviation and reduced yield occur. In addition, if the temperature uniformity deviation of thermal conductivity is large, the life of the product may be shortened due to thermal stress and thermal shock. Accordingly, the present applicant basically provides a ceramic plate that can be used at a high temperature of 500℃ or higher as a base material, and can prevent leakage current by having a high volume resistivity even at a temperature of 500℃ or higher, and also has higher thermal conductivity at room temperature than usual, which can solve the above problems.

[0031] The ceramic plate layer included in the ceramic susceptor according to the present invention serves as a base material of the ceramic susceptor. The ceramic plate is a sintered body comprising, as a main phase, alumina (Al2O3), which not only has excellent electrical insulation properties and high hardness but is also stable at high temperatures, and aluminum nitride (AlN), which is stable at high temperatures and has excellent physical properties of electrical insulation properties and thermal conductivity.

[0032] In particular, the present invention is characterized by complementing both the problems that occur when alumina and aluminum nitride are used separately and the problems that occur when alumina and aluminum nitride are not mixed in the optimal ratio by mixing the alumina and aluminum nitride in an optimal ratio as in the present invention. Specifically, when alumina and aluminum nitride are mixed in an optimal ratio as in the present invention, the alumina phase and the aluminum nitride phase are evenly mixed and distributed without a change in the crystal phase, such as the formation of a secondary phase of the AlON phase, thereby maximizing the properties of the ceramic susceptor. In addition, in the process of manufacturing the ceramic plate layer, the sintering process is performed at an optimal temperature (less than 1,650°C, preferably 1,300°C or more and less than 1,650°C), thereby more thoroughly preventing the formation of a secondary phase. Accordingly, the ceramic plate layer satisfies 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 / m·K at room temperature.

[0033] The ceramic plate layer comprises alumina in an amount of more than 68 wt% and less than 99.8 wt%, preferably 70 to 95 wt%, more preferably 70 to 80 wt%, and most preferably 73 to 77 wt%. In addition, the ceramic plate layer comprises aluminum nitride in an amount of more than 0.2 wt% and less than 32 wt%, preferably 5 to 30 wt%, more preferably 20 to 30 wt%, and most preferably 23 to 27 wt%. If each of the alumina and the aluminum nitride does not satisfy the above content range, the volume resistivity at 500°C or the thermal conductivity at room temperature will not meet the requirements, and thus the ceramic properties that the volume resistivity of the ceramic plate layer at 500°C should be 1.0E+10 to 1.0E+13 Ω·cm and the thermal conductivity at room temperature should be 30 to 60 W / m·K will not be satisfied.

[0034] It is preferable that the purity of the above alumina and aluminum nitride is 99% or higher, and that their particles have a nano size, and it is preferable that both of them are used in the form of powder.

[0035] More specifically, the alumina particles may have a size ranging from nanometers to micrometers. For example, the alumina particles may be particles obtained by mixing alumina particles having a size of 3 to 5 μm and alumina particles having a size of about 50 nm in a weight ratio of about 7:3 and then pulverizing the mixture through a ball mill process. However, the particle size and mixing ratio may vary widely, and the ball mill process may be excluded, and thus the present invention is not limited to the above examples.

[0036] In addition, the average particle size (D50) of the aluminum nitride particles may be 0.5 to 1.5 ㎛, preferably 0.8 to 1.3 ㎛, and more preferably 0.9 to 1.2 ㎛. If the average particle size (D50) of the aluminum nitride particles is less than 0.5 ㎛, the reaction temperature may be lowered, which may cause a problem in that a secondary phase is generated by reacting with alumina at a low temperature. In addition, if the average particle size (D50) of the aluminum nitride particles exceeds 1.5 ㎛, a dense / close-packed structure with alumina may not be formed, which may cause a problem in that the density is lowered during the final sintering. In addition, in the present invention, it is preferable to exclude aluminum nitride particles having a nanometer size as much as possible.

[0037] Meanwhile, the ceramic plate layer may further include a dopant as needed. The dopant may be used for the purpose of further improving the thermal conductivity of the ceramic plate layer.

[0038] For example, when a conventional sintered body is applied to a substrate and a semiconductor ceramic heater or electrostatic chuck is used at a high temperature of 500°C or higher, the substrate may be broken by thermal shock due to the rapid temperature change of the heating element. However, in order to improve the thermal shock resistance of the substrate, a dopant is mixed in and applied to the heater or electrostatic chuck, thereby efficiently transferring the heat of the heating element and preventing the substrate from being broken by thermal shock. Examples of such dopants include one or more of magnesium oxide (MgO), yttria (Y2O3), graphene, and rare earth composite oxides.

[0039] When the ceramic plate layer includes a dopant, the dopant may be included 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 included in an amount of less than 0.05 parts by weight or not included at all based on 100 parts by weight of the total weight of the alumina and aluminum nitride, the problems that previously appeared may remain the same, or the effect that can be obtained by using the dopant may be significantly reduced, so that the degree of improvement in thermal conductivity may be minimal, and an unsintering problem may also occur. In addition, when the content of the dopant 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 decrease, and the thermal conductivity may tend to decrease and the sintering density may decrease. In addition, the color of the product may darken due to the influence of the dopant, or the color of the dopant may be expressed as it is. In addition, it is preferable that all dopants used in the present invention have a purity of 99% or more. In addition, it is preferable that each dopant is included in an amount of 0.05 to 0.5 wt%.

[0040] Magnesium oxide, which is one of the above dopants, may be included to improve the thermal conductivity and volume resistivity of the ceramic plate layer. The magnesium oxide can induce the formation of a MgAl2O4 phase or a MgAlON phase through sintering with the alumina and / or aluminum nitride. However, if the MgAl2O4 phase or the MgAlON phase is formed in excessive amounts, the density may decrease, which may actually lower the thermal conductivity. Therefore, even if the same components are used, it is necessary to control the contents of the components. For example, in the present invention, at least one of the MgAl2O4 phase and the MgAlON phase included in the final ceramic susceptor may 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 susceptor. In addition, there is no particular limitation on the particle size of the magnesium oxide, but it is preferable to exclude nanometer-sized particles that may exhibit a relatively weak effect.

[0041] The above yttria (Y2O3) may be included to improve the thermal conductivity of the ceramic plate layer. The purity of the yttria is preferably 99% or higher, and in terms of improving physical properties through densification, the yttria particles preferably have a nano-size, and such yttria is preferably used in the form of a powder. More specifically, the average particle size (D50) of the yttria particles may be 50 to 150 nm, preferably 70 to 120 nm, and even more preferably 90 to 100 nm. If the average particle size (D50) of the yttria particles is less than 50 nm, even if included in a trace amount, there is a concern that a problem such as the sintered body having the color (yellow, etc.) of the yttria particles may occur due to the characteristics of the nano-level yttria powder. In addition, when the average particle size (D50) of the yttria particles exceeds 150 nm, an incomplete sintered body may be formed during sintering, which may cause a decrease in thermal conductivity due to a decrease in density. In particular, when the average particle size (D50) of the yttria particles is on the micrometer level, this problem may be more pronounced.

[0042] The above graphene may also be included to improve the thermal conductivity of the ceramic susceptor. Preferably, the purity of the graphene is 99% or higher, the graphene particles have a nano-size, and such graphene is preferably used in the form of powder (Graphene nanopowder, 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 even 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 act as bridges between the graphene particles, and thus the effect of improving thermal conductivity may be minimal or non-existent. In addition, if the average particle size (D50) of the graphene particles exceeds 1.5 nm, the graphene particles may become entangled with each other and may not be well dispersed, which may cause a problem of reduced thermal conductivity due to a decrease in density.

[0043] Finally, the rare-earth composite oxide includes 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 including such rare-earth metals is preferably 99% or higher. The form of the rare-earth composite oxide is preferably a powder, and there is no particular limitation on the size of the powder particles.

[0044] The above rare earth composite oxide can further improve the thermal conductivity of the ceramic susceptor, and furthermore, by using the above rare earth composite oxide, the time required for dechucking can be reduced. The above rare earth composite oxide may include two or more types of rare earth metals as described above, and preferably include two to five different rare earth metals.

[0045] The rare earth composite oxide containing the above 2 to 5 different rare earth metals is a 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 ) and a composite oxide containing two different rare earth metals; a samarium-cerium-europium composite oxide (SmCeEuO X ), gadolinium-cerium-lanthanum composite oxide (GdCeLaO X ) and europium-gadolinium-samarium composite oxide (EuGdSmO X ) and a composite oxide containing three different rare earth metals; a samarium-cerium-gadolinium-europium composite oxide (SmCeGdEuO X ) and gadolinium-samarium-europium-lanthanum composite oxide (GdSmEuLaO X ) and a composite oxide containing four different rare earth metals; and a samarium-cerium-europium-gadolinium-lanthanum composite oxide (SmCeEuGdLaO X ) and other composite oxides containing five different rare earth metals; and in addition, any compound containing two to five different rare earth metals (oxides) may be used without special restrictions.

[0046] The rare earth composite oxide containing the above 2 to 5 different rare earth metals may contain different types of rare earth metals in various mixing ratios. For example, the rare earth composite oxide containing the above 2 to 5 different rare earth metals may contain 2 kinds of rare earth metals (oxides) in a weight ratio of 2.5 to 3.5: 1, 3 kinds of rare earth metals (oxides) in a weight ratio of 1 to 3.5: 0.5 to 2.5: 1, 4 kinds of 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 5 kinds of 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, etc., and the rare earth metals (oxides) may be appropriately combined so that the effect of the target rare earth composite oxide can be maximized. For example, SmCeEuO X 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 Is The weight ratio can be 2:1:1:1.5:1.

[0047] In the above rare earth composite oxide, one rare earth metal can be dissolved in the other (or any) rare earth metal oxide. Through this, the crystal structure of the rare earth metal oxide changes, and thus, the rare earth composite oxide can have an increased oxygen lattice defect compared to a single rare earth metal oxide. In this way, the rare earth composite oxide with an increased oxygen lattice defect has improved interfacial reactivity, and can thus effectively react with the interface or lattice oxygen of the components within the ceramic susceptor.

[0048] 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), but the present invention does not include rare earth metal oxides containing only one rare earth metal as a dopant.

[0049] Meanwhile, although the dopant was described above as including at least one of magnesium oxide, yttria, graphene, and rare earth metal oxides other than yttria, the present invention preferably includes magnesium oxide as the dopant. In addition, it is preferable to use magnesium oxide and graphene together as the dopant. In addition, it is more preferable to use magnesium oxide, graphene, and yttria together as the dopant. In addition, it is most preferable to use magnesium oxide, graphene, yttria, and a rare earth composite oxide together as the dopant.

[0050] If magnesium oxide and graphene are used together as dopants, the magnesium oxide may be included in an amount of 0.05 to 0.5 parts by weight, and the graphene may be included 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.

[0051] In addition, when magnesium oxide, graphene, and yttria are used together as dopants, the magnesium oxide may be included in an amount of 0.05 to 0.5 parts by weight, the graphene may be included in an amount of 0.05 to 0.5 parts by weight, and the yttria may be included 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.

[0052] In addition, when magnesium oxide, graphene, yttria, and rare earth composite oxides are used together as dopants, the magnesium oxide may be included in an amount of 0.05 to 0.5 parts by weight, the graphene may be included in an amount of 0.05 to 0.5 parts by weight, the yttria may be included in an amount of 0.05 to 0.5 parts by weight, and the rare earth composite oxide may be included 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.

[0053] Hereinafter, a coating layer formed on a ceramic plate layer of a ceramic susceptor according to the present invention will be described in detail.

[0054] Hereinafter, the term "yttrium-aluminum oxide" refers to Y3Al5O 12 (YAG), YAlO3 (YAlO2), Y4Al2O9 (YAM), and combinations thereof. The terms "YAG" and "YAG phase" are used interchangeably in the present invention.

[0055] As used herein, the term "alumina" should be understood to be aluminum oxide comprising Al2O3, the term "yttria" should be understood to be yttrium oxide comprising Y2O3, and the term "spinel" should be understood to be magnesium aluminate spinel comprising MgAl2O4.

[0056] It should also be noted that the terms "Core" and "Core particle" are used interchangeably in the present invention, and the terms "Shell" and "Shell particle" are also used interchangeably in the present invention.

[0057] The coating layer formed on the ceramic plate layer is positioned on the ceramic plate layer and is formed by sintering a core / shell structure material.

[0058] In addition, the coating layer formed by sintering the core / shell structure material satisfies the high volume resistance and thermal conductivity required for electrostatic chucks or ceramic heaters, and has high strength / hardness and density and excellent plasma resistance properties.

[0059] A ceramic susceptor formed with such a coating layer on a ceramic plate layer minimizes particle generation and has a low level of contamination with metals and particles even when exposed to extreme conditions such as high temperatures and high-energy plasma during a semiconductor manufacturing process.

[0060] Fig. 1 is a cross-sectional view of a core / shell structure material particle included in a ceramic susceptor of the present invention. More specifically, as illustrated in Fig. 1, the core / shell structure material includes a core comprising an aluminum compound and a shell surrounding the core and coated on the surface of the core.

[0061] The core includes a ceramic material having high volume resistivity and thermal conductivity, and preferably includes at least one of aluminum oxide and aluminum nitride (AlN) among aluminum compounds, and the aluminum oxide is preferably alumina (Al2O3). In addition, the core may further include various ceramic materials having high volume resistivity and thermal conductivity and used in conventional electrostatic chucks and ceramic heaters. However, it may be more preferable that the core includes only an aluminum compound. In addition, the aluminum compound is preferably included in the core in the form of a powder, and therefore, the core may have a form composed of particles.

[0062] The shell coated on the surface of the core includes a metal or ceramic mixture material having excellent plasma resistance.

[0063] The above plasma-resistant metal or ceramic compound is yttrium-aluminum garnet (Y3Al5O 12 , YAG), yttrium-aluminum perovskite (YAlO3, YAP) and yttrium-aluminum monoclinic (Y4Al2O9, YAM), yttrium-aluminum oxide, yttrium oxide, magnesium oxide, yttria-alumina-silica (Y2O3-Al2O3-SiO2, YAS), magnesium silicate (Mg2SiO4) and mullite (Mullite, 3Al2O3·2SiO2), and among these, yttrium-aluminum garnet (YAG, Y3Al5O 12 ), yttria (Y2O3) or magnesium oxide may be preferred as the plasma-resistant metal or ceramic compound.

[0064] In addition, it is preferable that the above-mentioned plasma-resistant metal or ceramic compound be included in the shell in the form of a powder, and therefore, the shell may have a form composed of particles.

[0065] Accordingly, the core / shell structure material may be, for example, in the form of yttrium-aluminum oxide shell particles, yttria shell particles, or magnesium oxide shell particles coated on the surface of alumina core particles or aluminum nitride core particles.

[0066] Meanwhile, the YAG shell particles can be formed by directly coating commercially available YAG powder on the surface of the core particle, or by coating YAG powder prepared by reaction sintering a powder mixture of yttrium oxide (e.g., Y2O3) and aluminum oxide (e.g., Al2O3) on the surface of the core particle.

[0067] However, it is preferable that by subjecting the powder coated with yttria on the surface of the alumina core particle or the surface of the aluminum nitride core particle to heat treatment and ball milling, all or at least a portion of the yttria is converted into a YAG phase by a reaction between the alumina or aluminum nitride and the yttria, so that the converted YAG phase surrounds the surface of the alumina core particle or the surface of the aluminum nitride core particle.

[0068] In other words, it is preferable to form the aluminum nitride-YAG core / shell structural material or the alumina-YAG core / shell structural material by forming an yttria coating layer on the surface of the aluminum nitride core particle or the surface of the alumina core particle, and performing heat treatment and ball milling treatment so that the yttria coated on the surface of the core particle can react with the aluminum nitride or alumina inside the coating layer and be converted into a YAG phase, thereby forming the aluminum nitride-YAG core / shell structural material or the alumina-YAG core / shell structural material.

[0069] At this time, it is preferable to appropriately adjust the content ratio of the alumina and yttria or the content ratio of the aluminum nitride and yttria so that the yttria coated on the surface of the alumina core particle or the aluminum nitride core particle for forming the YAG shell reacts with the alumina or aluminum nitride to completely convert into a YAG phase, and at the same time, the remaining amount of alumina or aluminum nitride after reacting with the yttria inside the shell converted into the YAG phase can form a core.

[0070] In the core / shell structural material, the content ratio of alumina and yttria or the content ratio of aluminum nitride and yttria is preferably adjusted to match the content of the YAG shell so that the YAG shell can be formed by converting all of the yttria into a YAG phase through the reaction of the alumina or aluminum nitride with yttria. At this time, the content of the alumina core particles or the aluminum nitride core particles is preferably 50 wt% to 85 wt% with respect to the total weight of the core / shell structural material, and the content of the YAG shell particles is preferably 15 wt% to 50 wt%.

[0071] If the content of the YAG shell particles is less than 15 wt%, the hardness and density of the coating layer manufactured through sintering of the core / shell structural material are reduced, making it difficult to secure sufficient plasma resistance. In addition, if the content of the YAG shell particles exceeds 50 wt%, the volume resistivity and thermal conductivity of the ceramic susceptor due to the coating layer are reduced, making it difficult to apply the same to an electrostatic chuck or ceramic heater.

[0072] Meanwhile, when the core / shell structure material is a material in which yttria shell particles are coated on the surface of alumina core particles or aluminum nitride core particles, the content of the alumina core particles or aluminum nitride core particles is preferably 70 wt% to 90 wt%, and the content of the yttria shell particles is preferably 10 wt% to 30 wt%.

[0073] Even in this case, the yttria shell particles are converted into a YAG phase through reaction sintering of the alumina core particles or aluminum nitride core particles and the yttria shell particles during the sintering process, and at this time, the content of the alumina core particles or aluminum nitride core particles with respect to the total weight of the coating layer is preferably 50 wt% to 85 wt%, and the content of the YAG is preferably 15 wt% to 50 wt%.

[0074] Here, the thickness ratio of the core and shell can be appropriately adjusted to achieve a composition that satisfies the content range of the core component of the core / shell structural material, i.e., alumina or aluminum nitride, and the shell component, i.e., YAG or yttria.

[0075] More specifically, when the particle radius of the core is R1 and the thickness of the shell (i.e., the distance from the outermost surface of the core to the outermost surface of the shell) is R2, when the core / shell structure material is formed of an aluminum nitride-YAG or alumina-YAG structure, it is preferable that the R1 / R2 value be 4 to 25. In addition, when the core / shell structure material is formed of an aluminum nitride-yttria or alumina-yttria structure, it is preferable that the R1 / R2 value be 9 to 42.

[0076] In addition, when the core / shell structure material is a material in which magnesium oxide shell particles are coated on the surface of alumina core particles or aluminum nitride core particles, the content of the alumina core particles or aluminum nitride core particles is preferably 97.2 wt% to 85 wt%, and the content of the magnesium oxide particles is preferably 2.8 wt% to 15 wt%.

[0077] And, in the sintering process, the magnesium oxide shell particles are converted into a magnesium aluminate spinel (MgAl2O4, hereinafter referred to as “spinel”) phase through reaction sintering of the alumina core particles or aluminum nitride core particles and the magnesium oxide shell particles. At this time, the content of the alumina or aluminum nitride with respect to the total weight of the coating layer is preferably 50 wt% to 90 wt%, and the content of the spinel is preferably 10 wt% to 50 wt%.

[0078] Here, the content of the alumina core particles or aluminum nitride core particles and the magnesium oxide shell particles can be controlled by adjusting the thickness ratio of the alumina core particles or aluminum nitride core particles and the magnesium oxide shell particles.

[0079] More specifically, when the particle radius of the core is R1 and the thickness of the shell (i.e., the distance from the outermost surface of the core to the outermost surface of the shell) is R2, when the core / shell structure material is composed of an aluminum nitride-magnesium oxide or alumina-magnesium oxide structure, it is preferable that the R1 / R2 value be 16 to 114.

[0080] Meanwhile, the shell may further include at least one selected from the group consisting of yttria-alumina-silica (Y2O3-Al2O3-SiO2, YAS), carbon (C), boron nitride (BN), silicon carbide (SiC), scandium (Sc), and niobium (Nb).

[0081] Next, the coating layer formed by sintering the core / shell structure material and positioned on the ceramic plate layer will be described in more detail. Fig. 2 is a cross-sectional view schematically illustrating the internal structure of the coating layer formed by sintering the core / shell structure material included in the ceramic susceptor of the present invention.

[0082] The above coating layer is formed by sintering the core / shell structure material described above, and has a structure in which particle phases constituting the shell form a continuous phase along the interface of the core particle phases. Here, the 'continuous phase' means that each shell particle phase surrounding a plurality of core particle phases is agglomerated (combined). Therefore, the overall shape of the coating layer has a form in which a plurality of core particle phases are partially positioned inside the continuous phase made of shells, as illustrated in Fig. 2.

[0083] The coating layer positioned on the ceramic plate layer is formed by mixing aluminum nitride or alumina material having high volume resistivity and thermal conductivity with YAG or spinel material having excellent plasma resistance properties, and is sintered using the core / shell structure material so that the aluminum nitride or alumina phase is surrounded by the YAG or spinel phase and is not exposed to plasma.

[0084] That is, the coating layer may be formed by sintering the above-described aluminum nitride-YAG core / shell structure material or the alumina-YAG core / shell structure material, or may be formed by sintering the above-described aluminum nitride-yttria core / shell structure material, the alumina-yttria core / shell structure material, the aluminum nitride-magnesium oxide core / shell structure material, or the alumina-magnesium oxide core / shell structure material.

[0085] When the aluminum nitride-YAG core / shell structure material or the alumina-YAG core / shell structure material is sintered in this way, as shown in FIG. 2, the YAG phases constituting the shell form a continuous YAG phase along the interface of the aluminum nitride or alumina phases constituting the core.

[0086] That is, the aluminum nitride or alumina particles are sintered while being surrounded by continuous YAG phases, and are formed so as not to be exposed on the surface of the coating layer.

[0087] Therefore, due to the internal crystal structure as described above, even when the coating layer is exposed to plasma, the aluminum nitride particles or alumina particles are exposed to plasma with minimal exposure, and only the YAG phase, which has relatively low chemical activity and excellent chemical corrosion resistance, is exposed to plasma, thereby improving the plasma resistance of the coating layer to a level equal to or similar to that of the YAG bulk sintered body.

[0088] In addition, due to the aluminum nitride or alumina phases present inside the coating layer and surrounded by the continuous YAG phases, there is an advantage in that the volume resistivity and thermal conductivity of the coating layer can be maintained at a level equivalent to or similar to that of a conventional aluminum nitride or alumina bulk sintered body.

[0089] In addition, as can be seen from the above description, since the coating layer has similar properties to the ceramic plate layer, it is possible to bond to the ceramic plate layer with high strength, and accordingly, it has the advantage of significantly reducing peeling of the coating layer and generation of particles compared to the conventional method.

[0090] Meanwhile, when the coating layer is formed by sintering the aluminum nitride-yttria core / shell structure material or the alumina-yttria core / shell structure material, during the sintering process, all or at least a portion of the yttria constituting the shell is converted into a YAG phase by reaction sintering of the aluminum nitride or alumina constituting the core.

[0091] At this time, the YAG phase reacts with the yttria and forms a continuous YAG phase along the interface of the remaining aluminum nitride or alumina phases, as in the sintering of the aforementioned aluminum nitride-YAG core / shell structure material or alumina-YAG core / shell structure material.

[0092] Therefore, even in the case of a coating layer formed through sintering of the aluminum nitride-yttria core / shell structure material or the alumina-yttria core / shell structure material, it is possible to secure excellent plasma resistance properties by having the same internal crystal structure as the coating layer formed through sintering of the aluminum nitride-YAG core / shell structure material or the alumina-YAG core / shell structure material, and it is also possible to have high volume resistivity and thermal conductivity required by a conventional electrostatic chuck or ceramic heater.

[0093] In addition, when forming a coating layer through sintering of the aluminum nitride-magnesium oxide core / shell structure material or the alumina-magnesium oxide core / shell structure material, all or at least a portion of the magnesium oxide is converted into a spinel phase by reaction sintering of the magnesium oxide constituting the shell and the aluminum nitride or alumina constituting the core during the sintering process, and at this time, the converted spinel phase reacts with the magnesium oxide to form a continuous spinel phase along the interface of the remaining aluminum nitride or alumina phases.

[0094] Therefore, even in the case of a coating layer formed through sintering of the aluminum nitride-magnesium oxide core / shell structure material or the alumina-magnesium oxide core / shell structure material, the aluminum nitride particles or the alumina particles are surrounded by a spinel phase continuously formed along the interface, so that exposure to plasma is minimized, and only the spinel phase having relatively low chemical activity and excellent chemical corrosion resistance is exposed to plasma, so that not only can excellent plasma resistance characteristics be secured, but also high volume resistivity and thermal conductivity required by a typical electrostatic chuck or ceramic heater can be maintained.

[0095] In the coating layer formed in this way, the content of alumina or aluminum nitride present inside the alumina-YAG core / shell coating layer or the aluminum nitride-YAG core / shell coating layer is preferably 50 wt% to 85 wt%, and the content of YAG is preferably 15 wt% to 50 wt%. In addition, the content of alumina or aluminum nitride present inside the alumina-spinel core / shell coating layer or the aluminum nitride-spinel core / shell coating layer is preferably 50 wt% to 90 wt%, and the content of spinel is preferably 10 wt% to 50 wt%.

[0096] If the content of the alumina or aluminum nitride is less than 50 wt% outside the above content range, the volume resistivity and thermal conductivity of the ceramic susceptor due to the coating layer may decrease, which may cause problems in application to an electrostatic chuck or ceramic heater, and a problem in which the bonding strength with the ceramic plate layer may weaken may also occur. In addition, if the content of the alumina or aluminum nitride exceeds the upper limit of the above range, there is a problem in that the plasma resistance characteristics deteriorate due to a low content of the YAG or spinel phase contained therein.

[0097] In addition, if the content of the YAG or spinel is below the lower limit of the above range, it is difficult to expect plasma resistance characteristics equivalent to or similar to those of YAG or yttria bulk sintered body. In addition, if the content of the YAG or spinel exceeds 50 wt%, the volume resistivity and thermal conductivity may decrease, making it difficult to apply to an electrostatic chuck or ceramic heater, and the problem of weakening the bonding strength with the ceramic plate layer may also occur.

[0098] Here, the sintering performed when forming the coating layer is a method of forming bulk materials from powders using heat, pressure and / or energy, and can be performed through various sintering methods used for sintering conventional ceramic materials, and preferably can be performed by a hot press method.

[0099] In particular, when forming a coating layer using an aluminum nitride-yttria core / shell structure material or an alumina-yttria core / shell structure material, there may be a problem that the YAG phase is hardly formed because the reaction sintering between aluminum nitride-yttria or alumina-yttria does not occur smoothly in general atmospheric sintering, so it is preferable to manufacture it through a hot-press sintering process.

[0100] In the above-described embodiment, a coating layer having excellent plasma resistance and high volume resistivity and thermal conductivity is described by forming a continuous YAG or spinel phase along the interface of aluminum nitride or alumina phases constituting the core through sintering of the core / shell structure material.

[0101] However, the present invention is not limited thereto, and in addition to YAG or spinel, at the interface of the aluminum nitride or alumina phases, at least one selected from the group consisting of YAS (Yttria-Alumina-Silica or Yttrium aluminosilicate, Y2O3-Al2O3-SiO2), carbon (carbon, C), boron nitride (BN), silicon carbide (SiC), scandium (Sc), and niobium (Nb) may be further positioned.

[0102] These additional components can further improve the thermal conductivity, mechanical strength and hardness, density, etc. of the coating layer by being evenly dispersed along the interface of the aluminum nitride or alumina phases together with the YAG or spinel phase and distributed within the coating layer. In addition, there is an effect of further improving the overall physical properties of the ceramic susceptor manufactured using the coating layer.

[0103] Additionally, the additional components may be included in the process of forming the shell of the core / shell structure material, or may be added to the coating layer by being mixed and sintered together with the core / shell structure material in the process of manufacturing the coating layer through sintering of the core / shell structure material.

[0104] Accordingly, the additional components can play a role in improving the overall physical properties of the coating layer, such as thermal conductivity, mechanical strength, hardness, and density, by being evenly dispersed while forming a continuous phase along the interface of the aluminum nitride and alumina phases that constitute the core together with the shell component.

[0105] As described above, the present invention provides a coating layer having excellent plasma resistance and durability, in which a continuous YAG or spinel phase is formed along the interface of an alumina or aluminum nitride phase using a core / shell structure material.

[0106] In addition, the core / shell structure material and the coating layer using the same have high strength / hardness and density, and thus have the advantage of minimizing corrosion and erosion characteristics and particle and / or metal contamination in the extreme environment of semiconductor processes.

[0107] In particular, the coating layer has excellent plasma resistance and durability as described above, and not only has high volume resistance and thermal conductivity required when manufacturing an electrostatic chuck or ceramic heater, but also has similar physical properties to the ceramic plate layer, so that when formed on the ceramic plate layer, it has the advantage of being able to manufacture a ceramic susceptor with excellent performance that can reduce peeling of the coating layer or particle generation by securing excellent bonding strength.

[0108] In addition, the coating layer has the advantage of reducing manufacturing costs compared to conventional methods by reducing the content of expensive yttria by using a ceramic material with a core / shell structure.

[0109] Here, a method for manufacturing a coating layer using the core / shell structure material is described.

[0110] First, the method for manufacturing the core / shell structure material includes a step of mixing and reacting an aluminum compound and a plasma-resistant metal or ceramic compound, and may further include a step of ultrasonic treatment during the mixing and reaction.

[0111] The above ultrasonic treatment is intended to improve the dispersibility of a mixture, reactant or reaction product and promote uniform distribution of particles. There are no particular restrictions on the timing or number of times it is performed, such as after all raw materials are added or after only one raw material is added.

[0112] In addition, a linker such as urea (CO(NH2)2) may be separately supplied before, after, or during the input of raw materials. In addition, stirring may be performed simultaneously with the input of raw materials. In addition, the reaction between the raw materials may be performed in the presence of deionized water (3-distilled water).

[0113] For example, in the presence of Di Water (3-distilled water), an aluminum compound may be supplied to a reactor at about 90°C and stirred, followed by ultrasonic treatment at about 60°C for about 15 minutes. At this time, an additional stirring process may be performed for about 15 minutes to raise the temperature again to about 90°C. Subsequently, a linker may be introduced into the reactor, and after about 2 minutes from this point, ultrasonic treatment may be performed at about 60°C for about 15 minutes, and a stirring process may be performed again for about 15 minutes to raise the temperature again to about 90°C. In addition, any one or more of the above processes may be repeated 2 to 6 times, preferably 3 to 5 times. Subsequently, another raw material, a plasma-resistant metal or ceramic compound, may be additionally introduced into the reactor, and after about 2 minutes from this point, ultrasonic treatment may be performed at about 60°C for about 15 minutes, and a stirring process may be performed again for about 15 minutes to raise the temperature again to about 90°C. Finally, core / shell structured materials can be synthesized by additionally performing a stirring process for several minutes to several hours.

[0114] Meanwhile, for the purpose of removing unreacted residual linker and other impurities, a washing process using Di Water (three-distilled water) and alcohol can be performed, and this washing process can be repeated multiple times.

[0115] And, by drying the synthesized core / shell structure material at a temperature of about 70 to 90°C for 1 to 48 hours, preferably 12 to 36 hours, it is possible to obtain a core / shell structure material with higher purity.

[0116] Finally, the core / shell structure material manufactured as described above can be crushed using a ball mill or sintered using a hot-press method, thereby manufacturing a coating layer having a structure in which the particle phases constituting the shell form a continuous phase along the grain boundary of the core particle phases.

[0117] Here, yttrium-aluminum garnet (Y3Al5O) that can be included in the above 'shell' 12 , YAG) is briefly described. Conventional YAG manufacturing methods include sol-gel combustion, hydrothermal synthesis, and co-precipitation.

[0118] First, the sol-gel method is a method capable of producing "high-purity powders with uniform composition and fine particles." However, most of the nanoparticles produced are amorphous, requiring a heat treatment process for crystallization. Typically, temperatures above 800°C are required for a certain period of time to form a crystalline phase, which increases particle size and increases manufacturing costs.

[0119] Hydrothermal synthesis can produce "crystalline powders and powders with spherical, small particle sizes" at relatively low temperatures (200°C, 168 h). However, the synthesis process involves interactions between the powder and water, making it difficult to synthesize a complex oxide with a uniform composition. Furthermore, the process requires a significant amount of time.

[0120] Co-precipitation is a method for simultaneously precipitating various different ions from aqueous or non-aqueous solutions. It offers the advantage of uniform dispersion during the YAG manufacturing process, as the powder-like raw materials exist in their respective ionic forms. However, it also has the disadvantage of impurities co-precipitating during the precipitation process or insufficient dispersion, preventing complete precipitation.

[0121] Therefore, in order to synthesize YAG with a core / shell structure, high-purity particles must be manufactured, and for this purpose, the composition must be very uniform.

[0122] Accordingly, the applicant of the present invention has applied a method of improving the dispersibility of a mixture, reactant or reaction product by using a co-precipitation method and also by applying ultrasonic treatment, thereby inducing a uniform distribution of particles.

[0123] Meanwhile, by forming a reaction layer by reaction sintering at the interface between the ceramic plate layer and the coating layer, the stress caused by the difference in physical properties such as microstructure and thermal expansion coefficient between the ceramic plate layer and the coating layer is reduced, thereby making the coating interface more stable.

[0124] In the past, yttriana Y-based compounds were coated on AlN or Al2O3 ceramic plates, but after coating, stress due to differences in physical properties such as microstructure and thermal expansion coefficient at the interface was applied, resulting in a peeling phenomenon after coating. In particular, there was a problem in which the peeling phenomenon of the coating became more prominent in a high-temperature environment of 500°C or higher.

[0125] However, the present applicant formed a coating layer (formed by sintering a core / shell structure material) on a ceramic plate containing AlN and Al2O3 using a hot press sintering method. In particular, by making the core component within the coating layer and the component constituting the ceramic plate layer similar or identical, the difference in physical properties such as thermal expansion coefficient is minimized, enabling dense bonding, and accordingly, the degree of coating layer peeling or particle generation is significantly reduced compared to the conventional one, resulting in not only densification but also improvement in hardness and density.

[0126] In addition, the coating layer has a structure in which particle phases forming a shell along the interface of core particle phases, as described above, form a continuous phase. At this time, a material forming the continuous phase, for example, yttrium-aluminum garnet (Y3Al5O 12, YAG) is one of the major features of the present invention in that its own plasma properties are independently expressed separately from the effects exhibited by the core component.

[0127] In addition, by forming a coating layer using the sintering method described above, a reaction layer can be created by reaction sintering at the interface between the ceramic plate layer and the coating layer.

[0128] This reaction layer is created by reaction sintering using high temperature and high pressure energy, and stabilizes the microstructure of the interface between the ceramic plate layer and the coating layer, and relieves the stress caused by the difference in physical properties such as thermal expansion rate between the different materials constituting the ceramic plate layer and the coating layer, so that the coating layer can be stably maintained without peeling even in a high temperature environment of 500°C or higher.

[0129] For example, a continuous phase yttrium-aluminum garnet (YAG, Y3Al5O) is formed on a ceramic plate. 12 ) or yttria (Y2O3) coating layer' is formed, at the interface between the ceramic plate layer and the coating layer, yttrium-aluminum garnet (YAG, Y3Al5O) is formed by reaction sintering of the yttrium component included in the coating layer and the aluminum or alumina component present in the ceramic plate layer. 12 ) more reaction layers can be formed.

[0130] As another example, when a 'coating layer having a continuous phase of magnesium oxide' is formed on a ceramic plate, a magnesium aluminate spinel (MgAl2O4) reaction layer can be further formed at the interface between the ceramic plate layer and the coating layer by reaction sintering of the magnesium component included in the coating layer and the aluminum or alumina component present in the ceramic plate layer.

[0131] Next, a method for manufacturing a ceramic susceptor according to the present invention will be described.

[0132] The method for manufacturing the above ceramic susceptor includes the steps of 1) manufacturing a ceramic plate layer and 2) forming a coating layer on the ceramic plate layer.

[0133] And, the ceramic plate layer can be manufactured through the steps of a) mixing alumina (Al2O3), aluminum nitride (AlN), an alcohol compound, and a binder, b) drying the mixture to produce a powder from which the alcohol compound component is removed, c) compressing and molding the dried powder to produce a preform processed into a certain shape, d) degreasing the manufactured preform to remove the binder component, and e) sintering and polishing the degreasing preform.

[0134] And, if necessary, a dopant may be added and mixed in the step a), and examples of such dopant include one or more of magnesium oxide (MgO), yttria (Y2O3), graphene, and rare earth composite oxides.

[0135] The alcohol compound used in the above step a) is used for appropriate mixing of the raw materials, and examples thereof include alcohol compounds having 1 to 5 carbon atoms, specifically ethanol, methanol, and isopropyl alcohol. Similarly, the binder used in the above step a) is used for improving the binding strength of the raw materials, and examples thereof include polyvinyl alcohol (PVA) and polyvinyl butyral (PVB).

[0136] The step b) above is a step of drying the powder mixture mixed in the step a) above to remove the alcohol component. The drying may be performed by a method known in the art, such as a spray drying method or a vacuum drying method, and the drying time may be applied in various ways depending on the properties of the target ceramic susceptor.

[0137] The above step c) is a step for manufacturing a preform processed into a certain shape by compressing and molding the dried powder. The compression molding is the first molding (i.e., first molding) process for controlling the powder dried in the above step b) into a desired size and shape, and examples thereof include press molding. At this time, in order to manufacture a product with a more precise specification, cold isostatic pressing (CIP) may be additionally performed as needed. The press molding is preferably performed at room temperature and in a general atmosphere, but is not limited thereto, and the atmosphere during molding is sufficient as long as it does not affect the molding of the mixture. In addition, after the molding process of the above step c) is performed, processing by a green processing method (also called live processing, which is performed before sintering) or the like may be performed to manufacture a preform.

[0138] The above step d) is a step of degreasing the manufactured preform to remove the binder component. The degreasing is a process for removing the binder and oily contaminants, and can be performed at a temperature of 350 to 600°C for less than 60 hours.

[0139] The above step e) is a step of manufacturing a ceramic substrate by sintering (second molding) and polishing the degreased preform. The sintering is a second molding (i.e., second molding) process to further improve the volume resistivity, etc. of the ceramic susceptor, and it is preferable to use a hot press sintering method. In addition, when 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 causes a problem of lowering thermal conductivity. Therefore, the sintering in the above step e) must be performed at a temperature lower than 1,650°C, preferably higher than 1,300°C and lower than 1,650°C.

[0140] Next, in order to form a coating layer on the manufactured ceramic plate layer, a) a step of mixing and reacting an aluminum compound and a plasma-resistant metal or ceramic compound to manufacture a core / shell structure material, b) a step of dispersing the manufactured core / shell structure material in a solvent to manufacture a coating solution, c) a step of spraying the manufactured coating solution on the ceramic plate layer, and d) a step of forming a coating layer by drying the sprayed coating solution and then performing a hot press.

[0141] Step a) above may further include a step of ultrasonic treatment during mixing and reaction. Furthermore, the details of the raw materials in step a) above and the specific method for manufacturing the core / shell structural material are as described above.

[0142] The solvent in step b) above may be a typical organic solvent such as an alcohol-based compound.

[0143] There are no special restrictions on the spraying in step c) above, as any known spraying method for forming a coating layer, such as an air spray method, can be applied.

[0144] The drying in step d) above may be carried out for, for example, 10 minutes at room temperature, but is not limited thereto, and may vary depending on the coating amount or other environments.

[0145] The hot press in step d) above may be performed, for example, at a temperature of 1,300 to 1,650°C and a pressure of 100 to 200 bar for 1 to 24 hours, but is not limited thereto, and this may also be appropriately changed in consideration of the environment, etc.

[0146] Meanwhile, after manufacturing the core / shell structure material in step a) above or before performing the hot press in step d), a process of crushing the core / shell structure material with a planetary ball mill for 2 hours may be added.

[0147] By providing a coating layer (formed by sintering a core / shell structure material) on a ceramic plate layer containing AlN and Al2O3 through a process as described above, a sintered structure is formed in which similar or identical core components and ceramic plate layer components are in partial direct contact, and as a result, differences in physical properties such as thermal expansion coefficient are minimized, thereby enabling dense bonding.

[0148] And, by this, the degree of coating layer peeling or particle generation is significantly reduced compared to when a conventional coating layer is applied, and it has the advantage of improving not only densification but also hardness and density.

[0149] In addition, the shell, in which particle phases form a continuous phase along the interface of core particle phases, independently exhibits its own plasma-resistant properties, separate from the effects exhibited by the core component. This mechanism by which each component (core and shell) of the coating layer exhibits individual effects can be said to be a unique feature of the present invention that has not been found until now.

[0150] The ceramic susceptor of the present invention, manufactured using the above manufacturing method, can be applied to various devices or components used in semiconductor manufacturing processes, and is particularly preferably used as a material for heaters or electrostatic chucks used in semiconductor manufacturing processes. However, there are no particular limitations on its field of application, as it can also be used in fields that utilize ceramic materials under high-temperature plasma environments.

[0151] Hereinafter, the present invention will be described in more detail through specific examples. The following examples are intended to illustrate the present invention, and the present invention is not limited to the following examples.

[0152] [Manufacturing Examples 1-7] Manufacturing and Property Evaluation of Ceramic Plates

[0153] For the purpose of deriving the optimal mixing ratio of alumina and aluminum nitride, raw materials were mixed in the ratios shown in Table 1 below, and additionally, a small amount of ethanol and polyvinyl butyral (binder) were mixed and dried. Subsequently, the dried mixture was press-molded and processed to produce a green body, and then degreased at a temperature of 500°C for 30 hours, and then the degreased green body was sintered in a high-temperature pressurized sintering furnace (at a pressure of 250 bar and a temperature of 1,630°C) and polished to produce a ceramic plate.

[0154] And, the volume resistivity and thermal conductivity, etc. were measured for each manufactured ceramic plate. Specifically, after applying a voltage of 500 V / mm to each manufactured ceramic plate, the current was measured after 1 minute (measured under a vacuum atmosphere and room temperature) to calculate the volume resistivity. In addition, the thermal conductivity was calculated by manufacturing a specimen according to the standard of ASTM C0408-88R11 using LFA 467 equipment from NETZSCH and measuring it at room temperature. The results are shown in Table 2 below.

[0155] Al2O3:AlN (weight ratio) Manufacturing example 1100:0 Manufacturing example 299.8:0.2 Manufacturing example 395:5 Manufacturing example 485:15 Manufacturing example 575:25 Manufacturing example 668:32 Manufacturing example 760:40

[0156] Volume resistivity (@ 500℃, Ω·cm)Thermal conductivity (@ room temperature, W / m·K)Density (g / cm) 3) Hardness (Gpa) XRD result (weight%) Al2O3AlN Manufacturing example 11.6E+1323.23.95717.21000 Manufacturing example 21.1E+1328.43.95917.199.50.5 Manufacturing example 33.3E+1131.73.89616.594.75.3 Manufacturing example 48.8E+1033.23.80115.183.816.2 Manufacturing example 53.0E+1035.13.75514.776.123.9 Manufacturing example 69.8E+0936.33.69614.267.132.9 Manufacturing example 75.3E+0842.13.62513.659.740.3

[0157] * Al2O3 and AlN units: wt%

[0158]

[0159] As can be seen from Tables 1 and 2 above, the ratio of the aluminum nitride phase also changes depending on the addition ratio of aluminum nitride, and thereby the volume resistivity at high temperature and the thermal conductivity at room temperature change.

[0160] More specifically, the change in physical properties according to the addition ratio of aluminum nitride was confirmed, and the XRD results showed that the AlON phase was not formed in any of the final products of Manufacturing Examples 1 to 7. In addition, Manufacturing Examples 3 to 5 showed satisfactory volume resistivity and thermal conductivity, and Manufacturing Example 5, which mixed alumina and aluminum nitride at a weight ratio of 75:25, showed the best performance overall.

[0161] Through this, if the content of aluminum nitride is too low, the Al2O3 phase is formed as the main phase, so there is little effect of improving thermal conductivity, and if the content of aluminum nitride is excessively high, the ratio of the AlN phase increases, so there is an effect of improving thermal conductivity, but the volume resistivity and hardness tend to decrease.

[0162]

[0163] [Manufacturing Examples 5-1 to 5-5] Evaluation of properties of ceramic plates according to sintering temperature

[0164] Based on the results showing that Manufacturing Example 5, which mixed alumina and aluminum nitride in a weight ratio of 75:25, was the best overall, ceramic plates were manufactured by setting only the sintering temperature differently as shown in Table 3 below (same as the manufacturing method of Example 1 except for the composition and sintering temperature).

[0165] Then, the volume resistivity and thermal conductivity, etc., were measured for each manufactured ceramic plate. Specifically, after applying a voltage of 500 V / mm to the ceramic plate, the current was measured after 1 minute (measured under a vacuum atmosphere and room temperature) to calculate the volume resistivity. In addition, the thermal conductivity was calculated by measuring the specimens manufactured according to the standard of ASTM C0408-88R11 using the LFA 467 equipment of NETZSCH at room temperature. The results are shown in Table 4 below.

[0166] Al2O3: AlN (weight ratio) Sintering temperature (℃) Manufacturing example 5-175: 251,500 Manufacturing example 5-275: 251,550 Manufacturing example 5-375: 251,630 Manufacturing example 5-475: 251,650 Manufacturing example 5-575: 251,700

[0167] Volume resistivity (@ 500℃, Ω·cm)Thermal conductivity (@ room temperature, W / m·K)Density (g / cm) 3 ) Hardness (Gpa) XRD result (weight%) Al2O3AlNAlON Manufacturing example 5-1 Not measurable 18.13.423 13.27 4.825.20 Manufacturing example 5-29.9E+09 32.23.71 814.47 5.424.60 Manufacturing example 5-33.0E+10 35.13.75 514.77 6.123.90 Manufacturing example 5-44.4E+11 24.83.76 515.17 1.123.85.1 Manufacturing example 5-56.2E+11 19.43.77 516.55 8.217.324.5

[0168] * Al2O3, AlN and AlON units: wt%

[0169]

[0170] Alumina reacts with aluminum nitride above a certain temperature to form an AlON phase. Although the AlON phase has high electrical insulation, it has low thermal conductivity, so the formation of the AlON phase has a great influence on the physical properties. Fig. 3 is an XRD graph showing the physical properties of a ceramic susceptor according to the sintering temperature, and Fig. 4 is a graph showing the correlation between the alumina content and the sintering temperature. Referring to Figs. 3 and 4, at a sintering temperature of 1,500°C, non-sintering occurred, making it impossible to measure the volume resistivity, and the thermal conductivity and density were measured to be very low. As a result of analysis of the XRD graph, the AlON phase was formed at a sintering temperature of 1,650°C or higher, and as the AlON content increased, the volume resistivity increased, but the thermal conductivity tended to decrease rapidly. Therefore, it can be seen that the sintering in the present invention is preferably performed at a temperature below 1,650°C.

[0171]

[0172] [Manufacturing Examples 8-19, Comparative Manufacturing Examples 8-19] Manufacturing of Ceramic Plates

[0173] Considering the experimental results of the above Manufacturing Example 5-3, the raw materials were mixed according to the composition in Table 5 below, and additionally, a small amount of ethanol and polyvinyl butyral (binder) were mixed and dried. Subsequently, the dried mixture was press-molded and processed to produce a preform, and then degreased at a temperature of 500°C for 30 hours, and then the degreased preform was sintered in a high-temperature pressurized sintering furnace (at a pressure of 250 bar and a temperature of 1,630°C) and polished to produce a ceramic plate.

[0174] Al2O3: AlN (weight ratio) Dopant MgOGNP (Graphene nano powder) Nano Y2O3 Rare earth composite oxide Manufacturing example 875: 250.05 Manufacturing example 975: 250.1 Manufacturing example 1075: 250.5 Manufacturing example 1175: 250.10.05 Manufacturing example 1275: 250.10.1 Manufacturing example 1375: 250.10.5 Manufacturing example 1475: 250.10.10.05 Manufacturing example 1575: 250.10.10.1 Manufacturing example 1675: 250.10.10.5 Manufacturing example 1775: 250.10.10.10.05 Manufacturing example 1875: 250.10.10.10.1 Manufacturing Example 1975: 250.10.10.10.5 Comparative Manufacturing Example 875: 250.01 Comparative Manufacturing Example 975: 251 Comparative Manufacturing Example 1075: 253 Comparative Manufacturing Example 1175: 250.10.01 Comparative Manufacturing Example 1275: 250.11 Comparative Manufacturing Example 1375: 250.13 Comparative Manufacturing Example 1475: 250.10.10.01 Comparative Manufacturing Example 1575: 250.10.11 Comparative Manufacturing Example 1675: 250.10.13 Comparative Manufacturing Example 1775: 250.10.10.10.01 Comparative Manufacturing Example 1875: 250.10.10.11 Comparative Manufacturing Example 1975: 250.10.10.13

[0175] * Dopant unit: wt%

[0176]

[0177] [Experimental Example 1] Evaluation of Volume Resistance and Thermal Conductivity of Ceramic Plates

[0178] After applying a voltage of 500 V / mm to each ceramic plate manufactured from the above Manufacturing Examples 8 to 19 and Comparative Manufacturing Examples 8 to 19, the current was measured after 1 minute (measured under a vacuum atmosphere and room temperature) to calculate the volume resistivity, and the results are shown in Table 6 below.

[0179] In addition, each of the ceramic plates manufactured from the above Manufacturing Examples 8 to 19 and Comparative Manufacturing Examples 8 to 19 was measured at room temperature to produce a specimen according to the standard of ASTM C0408-88R11 using LFA 467 equipment from NETZSCH, and the thermal conductivity was calculated. The results are also shown in Table 6 below.

[0180] In addition, the density value of each ceramic plate manufactured from the above Manufacturing Examples 8 to 19 and Comparative Manufacturing Examples 8 to 19 was calculated using the Archimedes method, and the results are also shown in Table 6 below.

[0181] Volume resistivity (@ 500℃, Ω·cm)Thermal conductivity (@ room temperature, W / m·K)Density (g / cm) 3) Hardness (Gpa) Manufacturing example 84.0E+1036.93.75515.4 Manufacturing example 95.1E+1037.13.75115.2 Manufacturing example 108.3E+1037.33.75715.8 Manufacturing example 114.9E+1040.23.75015.4 Manufacturing example 124.4E+1041.83.74215.3 Manufacturing example 134.3E+1042.63.70715.1 Manufacturing example 144.5E+1043.03.74516.1 Manufacturing example 157.0E+1044.43.74216.3 Manufacturing example 168.1E+1049.13.75616.9 Manufacturing example 177.1E+1045.33.75116.5 Manufacturing Example 189.5E+1050.73.76716.8 Manufacturing Example 197.4E+1050.23.77416.5 Comparative Manufacturing Example 83.2E+1036.23.75215.1 Comparative Manufacturing Example 91.2E+1124.13.76116.3 Comparative Manufacturing Example 102.7E+1117.73.78815.9 Comparative Manufacturing Example 115.3E+1037.23.74815.3 Comparative Manufacturing Example 122.9E+0824.23.60813.8 Comparative Manufacturing Example 131.7E+0718.43.48911.2 Comparative Manufacturing Example 141.4E+1038.83.73315.7Comparative manufacturing example 156.2E+0937.03.76417.2Comparative manufacturing example 168.8E+0728.53.76116.8Comparative manufacturing example 176.2E+1039.13.73216.3Comparative manufacturing example 182.8E+0937.13.78117.1Comparative manufacturing example 197.2E+0722.93.79517.1

[0182] As a result of measuring the volume resistivity and thermal conductivity of each ceramic plate manufactured in Manufacturing Examples 8 to 19 and Comparative Manufacturing Examples 8 to 19, as shown in Table 6, all of the ceramic plates of Manufacturing Examples 8 to 19 satisfied the volume resistivity (1.0E+10 Ω·cm to 1.0E+13 Ω·cm) at 500°C required by the next-generation semiconductor manufacturing process.

[0183] In addition, in the case of thermal conductivity, as can be confirmed through the comparison of Manufacturing Examples 8 to 10 with Comparative Manufacturing Examples 8 to 10, the comparison of Manufacturing Examples 11 to 13 with Comparative Manufacturing Examples 11 to 13, the comparison of Manufacturing Examples 14 to 16 with Comparative Manufacturing Examples 14 to 16, and the comparison of Manufacturing Examples 17 to 19 with Comparative Manufacturing Examples 17 to 19, Manufacturing Examples 8 to 19, in which each dopant was used in a content of 0.05 to 0.5 wt%, were superior to Comparative Manufacturing Examples 8 to 19, in which even one dopant was used in an amount exceeding 0.05 to 0.5 wt%.

[0184] Meanwhile, when GNP (graphene nanopowder) was added as a dopant in addition to MgO, the effect was minimal when GNP was used at less than 0.05 wt%, whereas thermal conductivity improved when used at 0.05 to 0.5 wt%. In addition, when GNP was used at a content exceeding 0.5 wt%, the volume resistivity, density, and hardness tended to decrease rapidly.

[0185] In addition, even when nano-sized yttria (Y2O3) was added as a dopant in addition to MgO and GNP, when used at 0.05 to 0.5 wt%, the sinterability was improved, and the volume resistivity and thermal conductivity were increased. However, when yttria was used in a content exceeding 0.5 wt%, secondary phases such as YAP, YAM, and YAG were formed in large quantities due to the reaction with alumina, showing a tendency to decrease the thermal conductivity.

[0186] In addition, when rare earth composite oxides were added in addition to MgO, GNP, and Nano Y2O3 as dopants, it was confirmed that when used in amounts of 0.05 to 0.5 wt%, not only did the volume resistivity and thermal conductivity tend to increase, but also the density and hardness increased. On the other hand, when rare earth composite oxides were used in amounts exceeding 0.5 wt%, both the volume resistivity and thermal conductivity tended to decrease rapidly.

[0187] In addition, when comparing Manufacturing Example 9 with Comparative Manufacturing Example 9, Manufacturing Example 9 used 0.5 wt% of MgO, and Comparative Manufacturing Example 9 used 1 wt% of MgO, so there was not a significant difference in the content. However, the thermal conductivity decreased rapidly when 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 generated in an excess of more than 0.6 wt% in the final product, thereby increasing the fraction. These results can be confirmed through Table 7 below.

[0188] Al2O3: AlN (weight ratio) Dopant XRD result (weight %) MgOAl2O3AlNMgAl2O4 or MgAlON Manufacturing example 875: 250.0575.124.90 Manufacturing example 975: 250.175.024.80.2 Manufacturing example 1075: 250.574.824.60.6 Comparative manufacturing example 875: 250.0174.825.20 Comparative manufacturing example 975: 25174.624.11.3 Comparative manufacturing example 1075: 25373.423.82.8

[0189] * Dopant unit: wt%

[0190]

[0191] [Example 1] Manufacture of ceramic susceptor

[0192] First, in the presence of Di Water (3-distilled water), alumina was supplied to a reactor at 90°C, and after 2 minutes, it was subjected to ultrasonic treatment at 60°C for 15 minutes, and then stirred for an additional 15 minutes until the temperature was raised to 90°C. Next, urea (CO(NH2)2) was supplied to the reactor as a linker, and after 2 minutes, it was subjected to ultrasonic treatment at 60°C for 15 minutes, and then stirred for 15 minutes until the temperature was raised to 90°C. This process was repeated a total of 4 times. Subsequently, yttria, another raw material, was additionally supplied to the reactor, and after 2 minutes, it was subjected to ultrasonic treatment at 60°C for 15 minutes, and then stirred for 15 minutes until the temperature was raised to 90°C. Subsequently, a stirring process was additionally performed for about 3 hours to synthesize a core / shell structure material, and a washing process using Di Water and ethanol was performed four times to remove unreacted residual linkers and other impurities. Afterwards, to increase the purity of the synthesized core / shell structure material, it was dried in an oven at 80°C for 24 hours.

[0193] Meanwhile, alumina and yttria used in the synthesis of core / shell structural materials were introduced into the reactor at a weight ratio of 70:30, and the linker was used at 800 parts by weight per 100 parts by weight of yttria introduced (i.e., when linker was introduced once, 200 parts by weight was used per 100 parts by weight of yttria introduced).

[0194] Subsequently, the core / shell structure material manufactured above was ground for 2 hours using a planetary ball mill and then dispersed in ethanol to manufacture a coating solution, which was sprayed onto the ceramic plate manufactured in Manufacturing Example 18 using an air spray method.

[0195] Finally, a ceramic susceptor was manufactured by hot-pressing the ceramic plate onto which the coating solution was sprayed at a temperature of 1,570°C for 4 hours (coating layer composition after sintering: alumina 75.81 wt% / YAG 24.19 wt%), and a structure in which particle phases constituting the shell (YAG) formed a continuous phase along the interface of core (alumina) particle phases was formed as a coating layer on the ceramic plate.

[0196]

[0197] [Comparative Example 1] Manufacturing of a conventional ceramic susceptor

[0198] A ceramic susceptor was manufactured by molding and sintering alumina according to a conventional method (starting composition: 100 wt% alumina, composition after sintering: 100 wt% alumina).

[0199]

[0200] [Comparative Example 2] Manufacturing of a conventional ceramic susceptor

[0201] Yttrium-aluminum garnet (Y3Al5O) according to the conventional method 12 , YAG) was molded and sintered to manufacture a ceramic susceptor (starting composition: 100 wt% YAG, composition after sintering: 100 wt% YAG).

[0202]

[0203] [Comparative Example 3] Manufacturing of a conventional ceramic susceptor

[0204] A ceramic susceptor was manufactured by molding and sintering yttria according to a conventional method (starting composition: 100 wt% yttria, composition after sintering: 100 wt% yttria).

[0205]

[0206] [Comparative Example 4] Manufacturing of a Conventional Ceramic Susceptor

[0207] A ceramic susceptor containing YAG and alumina in independent phases was manufactured by mechanically mixing 60 wt% of alumina and 40 wt% of yttria according to a conventional method and then sintering them (starting composition: 60 wt% of alumina / 40 wt% of yttria, composition after sintering: 30.2 wt% of alumina / 69.8 wt% of YAG).

[0208]

[0209] [Comparative Example 5] Manufacturing of a conventional ceramic susceptor

[0210] A ceramic susceptor containing YAG and alumina in independent phases was manufactured by mechanically mixing 70 wt% of alumina and 30 wt% of yttria according to a conventional method and then sintering them (starting composition: 70 wt% of alumina / 30 wt% of yttria, composition after sintering: 49.06 wt% of alumina / 50.94 wt%).

[0211]

[0212] Fig. 5 is an XRD graph for a coating layer of a ceramic susceptor according to an embodiment of the present invention (specifically, corresponding to the ceramic susceptor manufactured in Example 1), and Fig. 6 is an XRD graph for a conventional ceramic susceptor (specifically, corresponding to the ceramic susceptor manufactured in Comparative Example 5). It can also be confirmed that the composition is equivalent to that after sintering through the results calculated through peak values ​​at specific 2θ.

[0213]

[0214] [Comparative Example 6] Manufacturing of a conventional ceramic susceptor

[0215] A ceramic susceptor containing YAG and alumina in independent phases was manufactured by mechanically mixing 80 wt% of alumina and 20 wt% of yttria according to a conventional method and then sintering them (starting composition: 80 wt% of alumina / 20 wt% of yttria, composition after sintering: 64.91 wt% of alumina / 35.09 wt%).

[0216]

[0217] [Comparative Example 7] Manufacturing of a conventional ceramic susceptor

[0218] A ceramic susceptor containing YAG and alumina in independent phases was manufactured by mechanically mixing 90 wt% alumina and 10 wt% yttria according to a conventional method and then sintering them (starting composition: 90 wt% alumina / 10 wt% yttria, composition after sintering: 82.24 wt% alumina / 17.76 wt% YAG).

[0219]

[0220] [Experimental Example 2] Tissue Evaluation of Ceramic Susceptors

[0221] As a result of confirming the phase morphology of the ceramic susceptors manufactured in Example 1 and Comparative Examples 1 to 7, as shown in Table 8 below, it was found that the ceramic susceptor of Example 1 had a structure in which YAG phases forming a shell along the interface of alumina particle phases formed a continuous phase and were densely bonded on the ceramic plate layer. On the other hand, it was confirmed that Comparative Examples 1 to 3 were composed of only a single phase, and Comparative Examples 4 to 7 were composed of two phases, but were independent of each other.

[0222] Phase morphology after sintering Example 1 A structure in which particle phases forming a shell along the interface of core particle phases form a continuous phase is densely bonded on a ceramic plate layer Comparative example 1 Single phase Comparative example 2 Single phase Comparative example 3 Single phase Comparative example 42 phases exist independently of each other Comparative example 52 phases exist independently of each other Comparative example 62 phases exist independently of each other Comparative example 72 phases exist independently of each other

[0223] FIG. 7 is an image (FIG. 7a, FIG. 7b) of a coating layer of a ceramic susceptor according to an embodiment of the present invention observed using a transmission electron microscope (TEM), FIG. 8 is an image of a cross-section of a ceramic susceptor according to an embodiment of the present invention observed using a scanning electron microscope (SEM), FIG. 9 is an image of a cross-section of a coating layer of a ceramic susceptor according to an embodiment of the present invention observed using a scanning electron microscope (SEM), and FIG. 10 is an image of a cross-section of a conventional ceramic susceptor observed using a scanning electron microscope.

[0224] More specifically, when the ceramic susceptor manufactured in Example 1 was observed using a transmission electron microscope, as shown in Figures 7a and 7b, a clear difference in brightness between the inner and outer portions of the coating layer was observed. In addition, the component analysis results confirmed that alumina was located in the inner portion and YAG was located in the outer portion.

[0225] Next, as a result of observing the cross-section of the ceramic susceptor and the cross-section of the coating layer manufactured in the above Example 1 using a scanning electron microscope (Fig. 8b is an enlarged view of a portion of the 'Core shell coating layer' in Fig. 8a), it was confirmed that the YAG particle phase formed a continuous phase along the interface (Grain Boundary) of the alumina particle phase, as shown in Fig. 8b and Fig. 9.

[0226] On the other hand, in the case of the ceramic susceptor manufactured in Comparative Example 5, as shown in Fig. 10, it was confirmed that although the alumina particle phase and the YAG particle phase were distinguished, they were composed of independent phases.

[0227] (For the remaining comparative examples 4, 6 and 7, where it was confirmed that the sintered body contained an alumina particle phase and a YAG particle phase, it was also confirmed that the alumina particle phase and the YAG particle phase were composed of independent phases.)

[0228]

[0229] [Experimental Example 3] Evaluation of the Properties of Ceramic Susceptors

[0230] After applying a voltage of 500 V / mm to each of the ceramic susceptors manufactured in Example 1 and Comparative Examples 1 to 7, the current was measured after 1 minute (measured under a vacuum atmosphere and room temperature) to calculate the volume resistivity, and the results are shown in Table 9 below.

[0231] In addition, each of the ceramic susceptors manufactured in Example 1 and Comparative Examples 1 to 7 was made into specimens according to the standard of ASTM C0408-88R11 using LFA 467 equipment from NETZSCH, and then the thermal conductivity was measured at room temperature to calculate the thermal conductivity, and the results are also shown in Table 9 below.

[0232] In addition, the density value of each of the ceramic susceptors manufactured in Example 1 and Comparative Examples 1 to 7 was calculated using the Archimedes method, and the results are also shown in Table 9 below.

[0233] In addition, the etching rate was measured for each of the ceramic susceptors manufactured in Example 1 and Comparative Examples 1 to 7 (plasma test), and the results are also shown in Table 9 below. A DektakXT Stylus Profiler (manufacturer: Bruker) was used to measure the etching rate.

[0234] In addition, the hardness of each of the ceramic susceptors manufactured in Example 1 and Comparative Examples 1 to 7 was measured, and the results are also shown in Table 9 below. A micro Vickers hardness tester (HM-210A, Mitutoyo) was used for the hardness measurement, and the microhardness scale was set to HV0.5.

[0235] Volume resistivity (@ 500℃, Ω·cm)Thermal conductivity (@ room temperature, W / m·K)Density (g / cm) 3) Etching rate (nm / min) Hardness (Gpa) Example 12.1E+1149.23.7922.331,780 Comparative example 11.0E+11233.94922.81,990 Comparative example 21.5E+08104.5644.51,356 Comparative example 31.2E+08134.6712.11600 Comparative example 45.7E+09154.372-1,511 Comparative example 54.8E+09184.2718.71,622 Comparative example 62.5E+10234.1789.91,780 Comparative example 76.0E+11304.07414.91,687

[0236] As a result of measuring the volume resistivity and thermal conductivity of each of the ceramic susceptors manufactured in Example 1 and Comparative Examples 1 to 7, as shown in Table 9, the ceramic susceptor of Example 1 satisfied the levels required for electrostatic chucks and ceramic heaters, etc., in both volume resistivity and thermal conductivity.

[0237] At the same time, the ceramic susceptor of Example 1 was found to have a hardness and density that could prevent or minimize corrosion and erosion properties and particle and / or metal contamination in the extreme environment of semiconductor processing.

[0238] Above all, the ceramic susceptor of Example 1 has an etching rate of only 2.33 nm / min, so even in a harsh plasma environment such as a high temperature and high energy plasma, the amount of etching byproducts and the generation of contaminant particles are small, and accordingly, it was confirmed that the yield loss of a semiconductor device can be minimized by using the ceramic susceptor of Example 1.

[0239] Meanwhile, the ceramic susceptor of Comparative Example 3 also had an etching rate of only 2.11 nm / min, but the remaining physical properties, i.e., volume resistivity, thermal conductivity, and hardness, were particularly very low, making it unsuitable as a ceramic susceptor for semiconductor manufacturing devices.

[0240] In addition, it can be seen that even if a ceramic susceptor including a YAG phase is manufactured by mixing and sintering alumina and yttria, it is not possible to exhibit excellent plasma resistance and other properties above the level simply by mechanical mixing and sintering.

[0241] Accordingly, it can be seen that the ceramic susceptor according to the present invention satisfies the levels required by electrostatic chucks, ceramic heaters, etc. in all of its main properties (volume resistivity, thermal conductivity, density, etching rate, and hardness).

[0242]

[0243] [Experimental Example 4] Coating layer peeling test on a ceramic susceptor

[0244] In order to observe whether the coating layer peels off at high temperatures, the ceramic susceptor manufactured in Example 1 was heat treated at 500°C, which is the actual use temperature, and the cross-section of the surface where the ceramic plate layer and the core / shell coating layer are bonded was observed using a scanning electron microscope (SEM) and the images are shown in FIGS. 11 and 12 (FIG. 11: 800 times magnification, FIG. 12: 2,000 times magnification).

[0245] As described above, after performing a heat treatment at 500°C on the ceramic susceptor manufactured in Example 1, the cross-section of the surface where the ceramic plate layer and the core / shell coating layer were bonded was observed using a scanning electron microscope. As shown in FIGS. 11 and 12, the bonding surface of the ceramic plate layer and the core / shell coating layer maintained a dense and stable bonding structure even in a high-temperature environment, and through this, it was confirmed that the bonding strength of the ceramic plate layer and the core / shell coating layer was maintained the same even under high temperatures.

[0246] Therefore, it can be seen that the ceramic susceptor according to the present invention can improve plasma resistance and particle resistance without peeling of the coating layer even in a high-temperature environment of 500°C, which is the temperature applied in an actual semiconductor manufacturing process.

[0247]

[0248] As described above, the present invention has been described with specific details such as specific components and limited examples and drawings, but this is only provided to help a more general understanding of the present invention, and the present invention is not limited to the above-described embodiments, and those with ordinary skill in the art to which the present invention pertains may make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the spirit of the present invention should not be limited to the described embodiments, and all technical ideas that are equivalent or equivalent to the claims described below as well as the claims should be interpreted as being included in the scope of the rights of the present invention.

Claims

1. Ceramic plate layer; and A coating layer formed by sintering a core / shell structural material, positioned on the above ceramic plate layer; The above ceramic plate layer includes alumina (Al2O3) and aluminum nitride (AlN), and does not include a secondary phase of aluminum oxynitride phase (AlON phase). The above coating layer is a ceramic susceptor having a structure in which particle phases forming a shell form a continuous phase along the grain boundary of core particle phases.

2. A ceramic susceptor according to claim 1, characterized in that the core particle phase comprises at least one of aluminum nitride and aluminum oxide.

3. In claim 1, the continuous phase is yttrium-aluminum garnet (Y3Al5O 12 A ceramic susceptor characterized by comprising a plasma-resistant metal or ceramic compound selected from the group consisting of yttrium-aluminum oxide, yttrium oxide, magnesium oxide, yttria-alumina-silica (Y2O3-Al2O3-SiO2, YAS), magnesium silicate (Mg2SiO4), and mullite (3Al2O3·2SiO2), selected from the group consisting of yttrium-aluminum perovskite (YAlO3, YAP), and yttrium-aluminum monoclinic (Y4Al2O9, YAM).

4. In claim 2, the continuous phase is yttrium-aluminum garnet (YAG, Y3Al5O 12 ), yttria (Y2O3) and magnesium oxide, characterized in that the ceramic susceptor is selected from the group consisting of:

5. In claim 4, the coating layer comprises yttrium-aluminum garnet (Y3Al5O) along the interface of aluminum nitride or aluminum oxide phases included on the core particle. 12 A ceramic susceptor characterized by having a structure in which a continuous phase is formed by YAG) or magnesium aluminate spinel (MgAl2O4).

6. A ceramic susceptor according to claim 5, characterized in that the content of aluminum nitride or aluminum oxide included on the core particle is 50 wt% to 85 wt% with respect to the total weight of the coating layer, and the content of yttrium-aluminum garnet forming the continuous phase is 15 wt% to 50 wt%.

7. A ceramic susceptor according to claim 5, characterized in that the content of aluminum nitride or aluminum oxide included on the core particle is 50 wt% to 90 wt% with respect to the total weight of the coating layer, and the content of magnesium aluminate spinel forming the continuous phase is 10 wt% to 50 wt%.

8. A ceramic susceptor according to claim 5, characterized in that at least one selected from the group consisting of yttria-alumina-silica (Y2O3-Al2O3-SiO2, YAS), carbon, boron nitride, silicon carbide, scandium, and niobium is further positioned at the interface of the aluminum nitride or aluminum oxide phases included on the core particle.

9. A ceramic susceptor according to claim 1, characterized in that the coating layer is formed on the ceramic plate layer by hot pressing.

10. A ceramic susceptor according to claim 4, characterized in that a reaction layer formed by reaction sintering is further formed at the interface between the ceramic plate layer and the coating layer.

11. In claim 10, the continuous phase is yttrium-aluminum garnet (YAG, Y3Al5O 12 ) or yttria (Y2O3), and yttrium-aluminum garnet (YAG, Y3Al5O) is present at the interface between the ceramic plate layer and the coating layer. 12 ) A ceramic susceptor characterized by the formation of a further reaction layer.

12. A ceramic susceptor according to claim 10, characterized in that the continuous phase is magnesium oxide, and a magnesium aluminate spinel (MgAl2O4) reaction layer is further formed at the interface between the ceramic plate layer and the coating layer.

13. A ceramic susceptor according to claim 1, characterized in that 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.

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