Composite insulator substrate, method for manufacturing the same, and electrostatic chuck device

Abstract

The application discloses a composite insulator substrate, a preparation method thereof and an electrostatic chuck device. The composite insulator substrate comprises a ceramic main body and a conductive component embedded in the ceramic main body. The ceramic main body and the conductive component both contain at least one variable valence metal compound sintering aid selected from oxides, nitrides, carbides and phosphides of variable valence metals Mn, Zr, Co, Cr, Ti, V and Fe, which effectively promotes the sintering density of the composite insulator substrate; meanwhile, a plasma discharge two-step heating sintering process is adopted to obtain a fine-grained ceramic microstructure. The composite insulator substrate provided by the application has a dense and fine-grained microstructure, which significantly improves the uniformity of the electrostatic adsorption force, enhances the interface bonding strength between the ceramic main body and the internal conductive component, prolongs the service life, and is suitable for high-end application scenarios such as semiconductor manufacturing.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing, and in particular to a composite insulating substrate, its preparation method, and an electrostatic chuck device. Background Technology

[0002] An electrostatic chuck, also known as an electrostatic chuck (ESC), is a type of clamp that uses electrostatic electrodes inside an insulator to generate electrostatic force to hold and hold objects such as wafers and glass panels. Electrostatic chucks can clamp and fix wafers without damaging them, and can adjust the wafer processing temperature using built-in heating electrodes. They are widely used in the semiconductor manufacturing industry and are core components of critical process equipment for etching, thin film deposition, ion implantation, and ashing.

[0003] The mainstream electrostatic chucks on the market mainly consist of a ceramic body, one or more conductive components embedded in the body, an aluminum base, and an adhesive layer connecting the body and the aluminum base. The conductive components in the electrostatic chuck include electrostatic adsorption electrodes, RF electrodes, and heating electrodes. The electrode materials are typically composed of refractory metals such as W, Mo, Pt, Pd, and Au, and their alloys. The coefficients of thermal expansion for refractory metals such as W and Mo are 4.5 × 10⁻⁶. -6 / ℃ and 5.2×10 -6 / ℃, while the thermal expansion coefficients of typical ceramic main materials Al2O3 and AlN are 6.4×10. -6 / ℃ and 4.5×10 -6 / ℃, and their coefficients of thermal expansion are on the same order of magnitude, differing only by 2×10. -6 While exhibiting good thermal stability, the sintering properties of the ceramic substrate and the refractory metal differ significantly. If only W and Mo powders are sintered on the surface of alumina ceramic, the W and Mo sintered layer will be porous and loose. The bonding strength and airtightness at the interface between the W and Mo metal electrode layer and the ceramic substrate will not meet the requirements. This may lead to warping, microcracks, or even peeling at the connection interface between the ceramic substrate and the electrostatic adsorption electrode, and between the ceramic substrate and the heating element. Consequently, this reduces the electrostatic adsorption force and heat conduction effect, shortening the service life of the electrostatic chuck. Therefore, adjusting and optimizing the sintering activity compatibility between the ceramic substrate material and the metal electrode of the electrostatic chuck is crucial for achieving higher interface bonding strength and extending service life. Summary of the Invention

[0004] To address the aforementioned issues, the present invention aims to introduce new sintering aids to improve the sintering activity compatibility between the ceramic substrate (ceramic layer) and the metal electrode layer, and to shorten the sintering time of the ceramic composite insulator substrate by employing a two-step rapid sintering method, thereby obtaining a dense, fine-grained structure, improving the mechanical properties and interfacial bonding strength of the electrostatic chuck, and ensuring its reliability and durability in the semiconductor manufacturing process.

[0005] To achieve the above objectives, the present invention provides a composite insulator substrate, comprising:

[0006] Ceramic body; and

[0007] Conductive components embedded inside a ceramic body;

[0008] The ceramic body comprises at least ceramic main material and sintering aid;

[0009] The main ceramic material includes at least one of Al2O3, Y2O3, AlN, BN, and SiC;

[0010] The sintering aid comprises a variable valence metal compound sintering aid, which includes at least one of an oxygen-containing compound, a nitrogen-containing compound, a carbon-containing compound, and a phosphorus-containing compound composed of a variable valence metal; the variable valence metal includes at least one of Mn, Zr, Co, Cr, Ti, V, and Fe.

[0011] The amount of variable valence metal compound sintering aid in the ceramic body is 0.1 to 10 wt% of the ceramic body material, preferably 0.5 to 5 wt%.

[0012] The conductive component is formed from at least conductive metal powder and ceramic powder, wherein the ceramic powder is uniformly distributed in the conductive metal powder; the ceramic powder comprises the ceramic main material and the variable valence metal compound sintering aid; the amount of the variable valence metal compound sintering aid accounts for 0.5 to 20 wt% of the total mass of the conductive metal powder, preferably 2 to 10 wt%.

[0013] Preferably, the conductive component comprises ceramic main material powder, and the amount used accounts for 0.1 to 10% wt% of the total mass of the conductive metal powder, preferably 0.5 to 5 wt%.

[0014] The conductive components are selected from at least one of the following metals and their alloys: Mo, W, Pt, Nb, Pd, Ag, Au.

[0015] The conductive component includes at least an electrostatic adsorption electrode, and may also include at least one of a heating electrode and / or an RF electrode.

[0016] The present invention also provides a method for preparing the above-mentioned composite insulator substrate, comprising:

[0017] Step S1: Provide the raw material slurry of the ceramic body to form ceramic sheets;

[0018] Step S2: Provide the raw material paste for the conductive component;

[0019] Step S3, Forming: Conductive components are formed within the ceramic sheet by screen printing or 3D printing;

[0020] Step S4, sintering into a ceramic block; and,

[0021] Step S5: Ceramic surface processing to obtain the composite insulator substrate.

[0022] Preferably, in step S4, sintering is carried out by spark plasma sintering under a non-oxidizing atmosphere, with a sintering temperature of 1250℃~1650℃, a sintering time of 1~90min, and a pressure of 5~80MPa.

[0023] Preferably, in step S4, the sintering is a two-step heating method, which is divided into a first stage and a second stage. The temperature of the first stage is 50-100°C higher than that of the second stage. The first stage is held at a temperature of 1-5 minutes, and the second stage is held at a temperature of 5-60 minutes.

[0024] Preferably, in step S5, the ceramic surface processing includes grinding and polishing to form a flat surface, and can also make protrusions and / or grooves on the flat surface, wherein the height of the protrusions is not higher than 50 μm and the total area is not greater than 2% of the ceramic disc surface.

[0025] The present invention also provides an electrostatic chuck device, comprising: a base, and the aforementioned composite insulator substrate formed on the base.

[0026] Compared with the prior art, the beneficial effects of the present invention include at least the following:

[0027] (1) Introducing variable valence metal compound sintering aids into the metal electrode layer and / or ceramic body material of conductive components enhances the sintering activity compatibility of the metal electrode layer and / or ceramic layer, promotes the sintering density of the metal electrode layer and / or ceramic layer, enhances the interfacial bonding strength between the metal electrode layer and the ceramic layer, improves the uniformity of electrostatic adsorption force, and extends the service life.

[0028] (2) The two-step heating sintering method using discharge plasma is adopted. The high temperature stage in the first stage is conducive to eliminating subcritical pores in the green body, providing a strong driving force and a short path for subsequent grain boundary diffusion. In the low temperature sintering stage in the second stage, grain boundary diffusion is the main process, the ceramic green body becomes denser, and the grains do not grow too fast. The sintering can be completed in a short time to obtain a fine-grained microstructure, which improves the resistance to plasma erosion and mechanical properties.

[0029] In addition to the technical problems solved by the present invention, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions as described above, other technical problems that the present invention can solve, other technical features contained in the technical solutions, and the beneficial effects brought about by these technical features will be further explained in detail with reference to the accompanying drawings. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of an electrostatic chuck structure (bipolar structure) containing a composite insulating substrate.

[0031] Figure 2 This is a schematic diagram of the testing area for the uniformity of electrostatic adsorption force distribution.

[0032] Figure 3 The following is a schematic diagram comparing the microstructure morphology of ultrasonic detection in the comparative example and Example 1: a represents the image of the interface between the electrostatic adsorption electrode layer and the ceramic layer of the composite insulator substrate obtained in the comparative example; b represents the image of the interface between the electrostatic adsorption electrode layer and the ceramic layer of the composite insulator substrate obtained in Example 1.

[0033] Figure 4 The following is a comparative schematic diagram showing the plasma etching morphology of the electrostatic chuck containing the composite insulator substrate prepared in the comparative example and Example 1: a represents a schematic diagram of the etching morphology of the surface of the composite insulator substrate prepared in the comparative example after plasma etching; b represents a schematic diagram of the etching morphology of the surface of the composite insulator substrate prepared in Example 1 after plasma etching.

[0034] Attached image labels:

[0035] Composite Insulator Substrate 10

[0036] Base 20

[0037] Adhesive layer 30

[0038] Ceramic body 1

[0039] Ceramic layers 11, 12, 13

[0040] Conductive Components 2

[0041] Electrostatic adsorption electrodes 21, 21'

[0042] Heating electrode 22

[0043] Cooling channel 4.

[0044] It should be understood that, attached Figure 1The components shown in the diagram are for simplicity and clarity in representing the structural schematic and are not necessarily drawn to scale. For example, the dimensions of some components may be enlarged relative to other components to aid in understanding the embodiments shown in this disclosure. Furthermore, some holes commonly found in electrostatic chucks, such as pin holes, He vent holes, and electrode holes, are omitted from the diagram. Detailed Implementation

[0045] The method for preparing the ceramic body of the multilayer composite insulator of the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be noted that these descriptions of embodiments are for the purpose of aiding understanding the present invention and do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0046] like Figure 1 The diagram shows a schematic of an electrostatic chuck structure containing a composite insulating substrate. The electrostatic chuck device includes a base 20 and a composite insulating substrate 10.

[0047] The base 20 is a metal aluminum and / or stainless steel base. The composite insulator substrate 10 can be fixed to the base 20 by an adhesive layer 30.

[0048] The composite insulating substrate 10 includes:

[0049] Ceramic body 1; and

[0050] The conductive component 2 is embedded inside the ceramic body. The conductive component 2 includes electrostatic adsorption electrodes 21 and 21'. In some embodiments, it may also include at least one of heating electrode 22 and / or RF electrode (not shown in the figure).

[0051] As an example, the composite insulating substrate 10 has a thickness of 900 μm and contains pin holes, He gas holes, and electrode terminal pre-reserved holes; the electrostatic adsorption electrodes 21 and 21' constitute a bipolar electrostatic chuck with an electrode layer thickness of 20 μm; the heating electrode 22 has a layer thickness of 20 μm; the adhesive layer 30 is made of silicone rubber with a thickness of 100 μm; the aluminum base 20 contains cooling channels 4, pin holes, and electrode terminal pre-reserved holes, wherein the cooling channels include He gas channels and coolant channels. Specifically, the electrostatic adsorption electrodes and the heating electrodes are completely covered by a ceramic insulating layer, and the electrode layer must avoid the locations of holes to protect the electrodes from corrosive gases and their plasma, while also preventing spark discharge damage to the wafer and electrostatic chuck during power-on.

[0052] To address the issues of bonding strength and airtightness between the ceramic body and conductive components of electrostatic chucks, functional additives are introduced into the product formulation to improve the density of the metal electrode layer and the interface between the metal electrode and the ceramic.

[0053] Patent CN114765122A utilizes vapor deposition or electrochemical deposition to coat interface materials such as MgO onto the surface of a metal electrode, forming an interface layer between the ceramic substrate layer and the metal electrode layer, effectively improving the interfacial bonding strength between the ceramic layer and the metal electrode layer. However, the commonly used spraying method easily generates internal stress within the coating. During the use of the electrostatic chuck, thermal expansion and contraction can cause cracks or even peeling of the interface layer, shortening the service life of the electrostatic chuck.

[0054] Patent JP2020043336A introduces Al2O3, NiO, and SiO2 additives into the W electrode layer, effectively improving the sintering density of the W electrode layer and enhancing the bonding strength between the W electrode layer and the unsintered Al2O3 ceramic substrate, thereby improving the electrostatic adsorption force of the electrostatic chuck at high temperatures. However, the absence of sintering aids within the ceramic substrate makes it difficult to control the density and abnormal grain growth of the Al2O3 ceramic, thus affecting the electrostatic chuck's resistance to plasma erosion and even causing spark discharge at pores, damaging the electrostatic chuck.

[0055] To address this, the present invention introduces a variable valence metal compound as a sintering aid. The variable valence metal compound sintering aid enhances the sintering activity matching degree between the metal electrode layer and the ceramic layer, thereby preparing a highly dense composite insulating substrate and effectively improving the interfacial bonding strength.

[0056] In some embodiments, the present invention introduces a variable valence metal compound as a sintering aid into the ceramic body to promote the sintering densification of the ceramic body (ceramic layer).

[0057] The variable valence metal includes at least one of Mn, Zr, Co, Cr, Ti, V, and Fe. As an example, the variable valence metal compound can be, for example, TiO2, Cr2O3, Fe2O3, MnO2, or V2O5. The function of such additives differs from conventional sintering aids such as CaO, MgO, and SiO2. These variable valence metal compounds do not form a liquid phase. Because their crystal structure is similar to or the same as that of the ceramic main material (such as Al2O3), and their ionic radii are similar, they readily form solid solutions in alumina, leading to lattice distortion. Furthermore, since they are all variable valence compounds, their valence can change during sintering, activating the lattice and significantly promoting sintering.

[0058] The ceramic body comprises a ceramic main material and at least one sintering aid. The ceramic main material includes at least one selected from Al2O3, Y2O3, AlN, BN, and SiC. The variable valence metal compound sintering aid includes at least one selected from oxygen-containing compounds, nitrogen-containing compounds, carbon-containing compounds, and phosphorus-containing compounds composed of variable valence metals; the amount of the variable valence metal compound sintering aid is 0.1–10 wt% of the ceramic main material, preferably 0.5–5 wt% of the ceramic main material. Further, the ceramic body contains a conventional sintering aid to inhibit grain growth, and the amount is 0.1–5 wt% of the ceramic main material. The conventional sintering aid includes at least one selected from oxygen-containing compounds, nitrogen-containing compounds, carbon-containing compounds, and phosphorus-containing compounds composed of any one of RE, Mg, Ca, Zn, Ba, Be, and Si, wherein RE is at least one selected from Y, Sm, Eu, La, Dy, Er, Tb, Gd, Pr, Tm, and Yb.

[0059] In some embodiments, the variable valence metal compound sintering aid is also introduced into the conductive component to promote the sintering densification of the conductive metal powder; the conductive component also includes the ceramic main material powder, which is uniformly distributed in the conductive metal powder to enhance the interfacial bonding strength between the metal electrode layer and the ceramic layer.

[0060] The amount of variable valence metal compound sintering aid in the conductive component accounts for 0.5 to 20 wt% of the total mass of the conductive metal powder, preferably 2 to 10 wt%.

[0061] Optionally, the conductive component comprises a ceramic main material, which accounts for 0.1 to 10% wt% of the total mass of the conductive metal powder, preferably 0.5 to 5 wt%.

[0062] The conductive components are selected from at least one of the following metals and their alloys: Mo, W, Pt, Nb, Pd, Ag, Au.

[0063] The conductive component includes at least an electrostatic adsorption electrode, and may also include at least one of a heating electrode and / or an RF electrode.

[0064] Furthermore, to address the strength and airtightness issues in the bonding between the ceramic substrate and conductive components, solutions have been sought in ceramic sintering processes. The ceramic substrate for electrostatic chucks is typically sintered using pressure sintering, commonly hot-pressing or hot-pressing followed by hot isostatic pressing. The pressure applied during hot-pressing promotes atomic flow within the particles; this pressure, along with the powder surface energy, acts as a driving force for sintering, enhancing diffusion. Because hot-pressing can be performed at lower temperatures, grain growth is suppressed, resulting in dense, uniform samples with small grains and high strength. However, hot-pressing typically has a long production cycle and high production costs. Spark plasma sintering (SPPS) is a relatively new sintering method developed in recent years. It utilizes the instantaneous high-temperature field generated by pulsed energy and pressure to spontaneously heat and activate the grains within the ceramic. This method offers rapid heating and cooling with short holding times, effectively suppressing grain growth, shortening the ceramic preparation cycle, and saving energy. The resulting ceramic samples exhibit fine grains, high density, and good mechanical properties, making it a valuable and promising sintering method.

[0065] This invention employs a two-step heating sintering method using discharge plasma. In the process of preparing high-purity ceramics by discharge plasma sintering, the sample is first heated to a specific temperature to eliminate subcritical pores in the green body, providing a strong driving force and a short path for subsequent grain boundary diffusion. Then, the temperature is lowered to achieve a denser green body. The prerequisite for complete densification of the green body is that during the shrinkage process, the pores in the green body are gradually expelled, and the grains do not grow too fast. This allows for sintering to be completed in a short time to obtain a fine-grained microstructure, which is beneficial for improving resistance to plasma erosion and mechanical properties.

[0066] This invention provides a method for preparing a composite insulator substrate, comprising:

[0067] Step S1: Provide the raw material slurry of the ceramic body to form a ceramic sheet.

[0068] The raw material slurry includes ceramic main material, variable valence metal compound sintering aid and conventional sintering aid.

[0069] Step S2: Provide the raw material slurry for the conductive components.

[0070] Step S3, shaping.

[0071] The ceramic sheet is cut and perforated to form ceramic layers 11, 12, and 13 of the required size and shape.

[0072] The forming method includes screen printing, that is, screen printing the raw material paste of the conductive components onto the lower surface of the ceramic layers 11 and 12; preferably, the forming method is 3D printing. The ceramic layers 13, 12, and 11 are positioned and stacked in order from bottom to top, and formed by isostatic pressing at 80°C to obtain a green blank.

[0073] Step S4: Sinter into a ceramic block.

[0074] The green blank is placed in a reduction furnace and degummed at 600°C for 5 hours under a 3% H2-N2 atmosphere, and then sintered in a high-temperature sintering furnace to obtain the composite insulator. The sintering method can be at least one of pressure sintering, spark plasma sintering, or microwave plasma sintering.

[0075] In this example, spark plasma sintering was used. The spark plasma sintering temperature was 1250℃~1650℃, the sintering time was 1~90min, the pressure was 5~80MPa, and the atmosphere was non-oxidizing. In particular, the sintering was carried out in two stages, with the first stage temperature being 50~100℃ higher than the second stage temperature, the first stage holding temperature being 1~5min, and the second stage holding temperature being 5~60min.

[0076] Step S5: Ceramic surface processing to obtain the composite insulator substrate 10.

[0077] Ceramic surface processing includes grinding, polishing, etc., to process the composite insulator substrate into a plane. In other embodiments, protrusions and / or grooves may also be formed on the plane, wherein the height of the protrusions is not higher than 50 μm and the total area is not greater than 2% of the ceramic disk surface.

[0078] The resulting composite insulator substrate 10 is bonded to the base 20 using an adhesive layer 30 (made of silicone rubber) to form an electrostatic chuck device.

[0079] The following description is based on comparative examples and embodiments.

[0080] "3N ultrafine powder" refers to ultrafine particulate materials with a purity of 99.9%, or three nines, abbreviated as 3N.

[0081] Taking Al2O3 as the main ceramic material and MnO2 and TiO2 as sintering aids of variable valence metal compounds as examples, MgO is a conventional sintering aid.

[0082] Polyacrylate additives are dispersants primarily used to disperse powder particles, reduce powder agglomeration, and promote uniform mixing between particles. Polyacrylate dispersants are typically made from polyacrylic acid (PAA) or its derivatives. These substances possess hydrophilic (water-soluble) and negatively charged properties, effectively stabilizing and dispersing particles and preventing particle agglomeration in liquids. The polyacrylate dispersant used in this invention is BASF Dispex AA4040.

[0083] Acrylic emulsion adhesives are water-based adhesives, primarily made from acrylic acid or its derivatives through emulsion polymerization. These adhesives exhibit good bonding properties, water resistance, and weather resistance, and because they are water-based, they are relatively environmentally friendly. The acrylic emulsion adhesive used in this invention is derived from Dow Adhesives Duramax B-1000.

[0084] Plasticizers, also known as plasticizers or softeners, are additives used to improve the plasticity, flexibility, and processing properties of materials. By adding plasticizers, the viscosity of ceramic slurries can be reduced, making them easier to coat, extrude, or injection mold. Furthermore, plasticizers can increase the strength of ceramic green bodies and reduce the risk of cracking during drying and sintering. The plasticizer used in this invention is Dow Duramax B-1022.

[0085] Comparative example

[0086] Commercially available 3N ultrafine powder was used. The D50 of the main ceramic material Al2O3 and the conventional sintering aid MgO were both 0.3 μm. The corresponding raw materials were weighed according to the formula shown in Table 1. After being ball-milled and mixed evenly in an aqueous solution containing 0.5 wt% (calculated as Al2O3) of polyacrylate dispersant, acrylic emulsion adhesive and plasticizer (ratio of 1:1, total amount of 30 wt% of Al2O3) were added. The mixture was cast into ceramic sheets, dried to remove moisture, and cut into ceramic layers 11, 12, and 13 of the required size and shape. Predetermined holes were drilled in the ceramic sheets for subsequent assembly and installation of electrodes or other components.

[0087] Mo metal powder paste (according to the electrode layer formulation in Table 1) was screen-printed onto the lower surfaces of ceramic layers 11 and 12, respectively. Figure 1The ceramic layers 11, 12, and 13 were sequentially positioned and stacked. After being formed by isostatic pressing at 80℃, they were debonded in a reduction furnace at 600℃ under a 3% H2-N2 atmosphere. The substrate was then sintered in a hot press furnace (HP) at 1450℃ and H2-N2-H2O(g) atmosphere for 8 hours at 60MPa to obtain a composite insulating substrate. Finally, the substrate was sandblasted, ground, and polished to obtain a composite insulating substrate with a thickness of 900µm. The height and diameter of the dot protrusions were 20µm and 2mm, respectively, and the height and width of the edge sealing ring protrusions were 20µm and 2mm, respectively. The surface roughness was 0.3µm, and the flatness was 2µm.

[0088] Example 1

[0089] In this embodiment, commercial 3N ultrafine powder was used, and a variable valence metal compound MnO2 with a D50 of 0.3 μm was added in addition to the comparative example. The corresponding raw materials were weighed according to the formula shown in Table 1, and ceramic layers 11, 12, and 13 were prepared using the same method as in the comparative example.

[0090] Mo metal powder paste (according to the electrode layer formulation in Table 1) was screen-printed onto the lower surfaces of ceramic layers 11 and 12, respectively. Figure 1 The ceramic layers 11, 12, and 13 were sequentially positioned and stacked, then isostatically pressed at 80℃. After debinding in a reduction furnace at 600℃ under a 3% H2-N2 atmosphere, the substrate was placed in a spark plasma sintering furnace (SPS) under an H2-N2-H2O(g) atmosphere and a pressure of 60MPa. The temperature was increased at a rate of 50℃ / min and held for 3 minutes, then decreased to 1350℃ and held for 30 minutes to obtain the composite insulator substrate. Finally, the substrate was sandblasted, ground, and polished to obtain a composite insulator substrate with a thickness of 900µm. The height and diameter of the dot protrusions were 20µm and 2mm, respectively, and the height and width of the edge sealing ring protrusions were 20µm and 2mm, respectively. The surface roughness was 0.3µm, and the flatness was 2µm.

[0091] Example 2

[0092] The variable valence metal compound in Example 1 was replaced with TiO2, which has a D50 of 0.3 μm.

[0093] The amounts of ceramic layer raw materials and electrode layer raw materials, as well as the sintering conditions, are shown in Table 1.

[0094] Table 1 Key process parameters of the composite insulator substrate in the embodiments.

[0095]

[0096] Adsorption force test

[0097] This invention tested the adsorption force of the electrostatic chucks in Comparative Examples and Example 1, mainly examining the distribution of adsorption force on the wafer at different locations on the chuck surface. The sample placement surface temperature of the 8-inch electrostatic chuck was set to 25°C. First, a voltage of 600V was applied to the electrostatic electrode and maintained for 60 seconds, causing a 2-inch silicon wafer to be adsorbed onto a designated location on the chuck surface (e.g., in a vacuum < 0.5Pa) in a vacuum. Figure 2 Then, a force sensor is used to peel off the electrostatic chuck from the silicon wafer, and the maximum peeling stress generated at this time is set as the adsorption force of the wafer on the local area. Figure 2 The numbers 1-9 represent the positions of the test wafers. The test results are shown in Table 2:

[0098] Table 2: Adsorption force test results of comparative examples and Example 1

[0099]

[0100] As can be seen from Table 2, in Example 1, a variable valence metal compound sintering aid was introduced into the ceramic body and the metal electrode layer, and a rapid sintering process of spark plasma was adopted, which significantly increased the electrostatic adsorption force of the composite insulator substrate, made the adsorption force distribution more uniform, and significantly improved the uniformity from 34.6% to 17.7%.

[0101] The structural image of the interface between the ceramic layer and the electrostatic adsorption electrode layer in a composite insulator substrate was obtained by ultrasonic flaw detection microscopy. Figure 3 Image a shows the interface between the electrode layer and the ceramic bonding layer of the composite insulator substrate obtained in the comparative example. The image exhibits grayscale differences and a small number of bubbles, indicating that this interface has numerous sintering defects. Figure 3 Image b shows the interface between the electrode layer and the ceramic layer of the composite insulator substrate obtained in Example 1. The structure is uniform and free of bubbles, indicating good bonding and no defects. This is because the variable valence compound MnO2 was introduced in Example 1. During the sintering process under a non-oxidizing atmosphere, MnO2 is reduced to MnO, which reacts with Al2O3 to form MnAl2O4 with a spinel structure. The variable valence of Mn can improve the lattice activity of alumina and promote the sintering density of alumina. At the same time, MnAl2O4 can adhere to alumina and Mo particles, promoting the sintering density of the W and Mo powder layers, and greatly improving the bonding strength between the ceramic and the electrode. The variable valence metal compound TiO2 introduced in Example 2 also has similar properties and can achieve technical effects comparable to those in Example 1.

[0102] Plasma corrosion resistance test

[0103] The present invention also conducted plasma corrosion resistance tests on the electrostatic chucks of Comparative Example and Example 1. The main body of the 8-inch electrostatic chuck was placed in the plasma chamber of the etching apparatus, and the composite insulator substrate was irradiated with 2000W etching gas (CF4:O2 = 4:1) for 20 hours. The surface of the composite insulator substrate after plasma corrosion was observed using a laser microscope. Figure 4 It can be seen that after plasma etching, the comparative example ( Figure 4 The corrosion pits in Example a) are significantly more numerous than in Example 1. Figure 4 b) indicates that the addition of a variable-valence metal compound sintering aid improves the plasma corrosion resistance of the composite insulating substrate. This is because the variable valence of Mn introduced in Example 1 increases the lattice activity of Al2O3, promoting the sintering density of Al2O3; simultaneously, the rapid heating during plasma sintering reduces grain growth caused by surface diffusion, refining the alumina ceramic grains, thereby significantly improving the plasma corrosion resistance of the composite insulating substrate.

[0104] In summary, this invention selects a variable-valence metal compound as a sintering aid, which can be added to the ceramic substrate or conductive components to promote the sintering density of the ceramic substrate or conductive components. Furthermore, a variable-valence metal compound sintering aid can also be added to the ceramic substrate and conductive components to enhance the bonding strength and mechanical properties of their interface. Through innovations in material selection, additive use, and manufacturing processes, this invention provides a high-performance, long-life composite insulating substrate and its electrostatic chuck device, suitable for high-end applications such as semiconductor manufacturing.

[0105] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A composite insulator substrate, characterized by, The application relates to a composite insulator substrate. The application relates to a composite insulator substrate. The ceramic body comprises at least a ceramic main material and a sintering aid. The ceramic main material comprises at least one of Al2O3, Y2O3, AlN, BN and SiC. The sintering aid comprises a variable-valence metal compound sintering aid, which comprises at least one of an oxygen-containing compound, a nitrogen-containing compound, a carbon-containing compound and a phosphorus-containing compound composed of a variable-valence metal, wherein the variable-valence metal comprises at least one of Mn, Zr, Co, Cr, Ti, V and Fe. The conductive component is formed by at least a conductive metal powder and a ceramic powder, wherein the ceramic powder is uniformly distributed in the conductive metal powder; the ceramic powder comprises the ceramic main material and the variable-valence metal compound sintering aid; and the variable-valence metal compound sintering aid accounts for 0.5-20 wt% of the total mass of the conductive metal powder. The variable-valence metal compound sintering aid accounts for 0.1-10 wt% of the mass of the ceramic main material. The variable-valence metal compound sintering aid accounts for 0.5-5 wt% of the mass of the ceramic main material.

2. The composite insulator substrate of claim 1, wherein, The variable-valence metal compound sintering aid accounts for 2-10 wt% of the total mass of the conductive metal powder.

3. The composite insulator substrate of claim 2, wherein, The conductive metal is selected from at least one of Mo, W, Pt, Nb, Pd, Ag and Au metal and alloys thereof.

4. The composite insulator substrate of claim 1, wherein The conductive component comprises an electrostatic adsorption electrode.

5. The composite insulator substrate of claim 4, wherein, The conductive component further comprises a heating electrode and / or an RF electrode.

6. The composite insulator substrate of claim 4, wherein, The application relates to a composite insulator substrate.

7. The composite insulator substrate of claim 6, wherein, In step S4, the sintering is performed by a spark plasma sintering mode, and the sintering temperature is 1250-1650 DEG C under a non-oxidizing atmosphere, the sintering time is 1-90 min, and the pressure is 5-80 MPa.

8. A method of producing a composite insulator substrate according to any one of claims 1 to 7, characterized by, In step S4, the sintering is performed by a two-step temperature rising method, which is divided into a first stage and a second stage; the temperature of the first stage is 50-100 DEG C higher than that of the second stage, the first stage is kept for 1-5 min, and the second stage is kept for 5-60 min. The application relates to a composite insulator substrate. The composite insulator substrate according to any one of claims 1-7 is formed on the base. ​ ​ ​ 9. The method of producing a composite insulator substrate according to claim 8, wherein ​ 10. The method of producing a composite insulator substrate according to claim 9, wherein ​ 11. An electrostatic chuck apparatus, comprising: ​ ​ ​

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