Multilayer composite ceramic plate and preparation method thereof

Abstract

According to the multilayer composite ceramic plate and the preparation method thereof, aluminum nitride with excellent heat-conducting property is used as a heat transfer layer of the ceramic plate, and aluminum oxide with higher cost effectiveness and better mechanical property and electrical performance is used as an adsorption surface dielectric layer of the ceramic plate, or is used as the adsorption surface dielectric layer and a substrate layer of the ceramic plate at the same time; the aluminum nitride heat transfer layer is clamped between the adsorption surface dielectric layer and the substrate layer, so that respective performance advantages of an aluminum nitride material and an aluminum oxide material can be brought into full play, the consumption of the aluminum nitride material is reduced, and the cost can be reduced while the excellent temperature uniformity of the ceramic plate is ensured; meanwhile, good adsorption performance and stable electric insulation performance are achieved, and the technical structure is effective, stable, reliable, complementary in advantages and high in cost effectiveness.

Description

Technical Field

[0001] This application relates to the technical field of semiconductor manufacturing, and in particular to a multilayer composite ceramic disk and its preparation method. Background Technology

[0002] In the field of semiconductor processing technology, electrostatic chucks are widely used in manufacturing equipment for integrated circuits (ICs) and other devices, such as in equipment for ETCH (Electro-Temperature Etching), Physical Vapor Deposition (PVD), and Chemical Vapor Deposition (CVD). By applying a high voltage between the two electrodes of the adsorption electrodes embedded inside the electrostatic chuck, an electrostatic attraction is generated to hold the wafer, preventing it from moving or misaligning during the process, providing radio frequency bias, and controlling the temperature of the wafer surface. Electrostatic chucks can be divided into two main categories based on their main material: alumina ceramic and aluminum nitride ceramic (generally used in electrostatic chucks and heaters). In semiconductor processing, wafer temperature control is crucial. If the wafer surface temperature cannot be uniform, the processing uniformity cannot be guaranteed, and the processing accuracy will be greatly affected. Aluminum nitride ceramic has excellent thermal conductivity, with a thermal conductivity of 320 W / (m·K), far exceeding that of alumina ceramic (35 W / (m·K)). Therefore, the industry currently uses aluminum nitride ceramic as the superior manufacturing material for electrostatic chucks.

[0003] However, the numerous shortcomings of aluminum nitride ceramics limit their use as a material for electrostatic chuck manufacturing, with a market penetration rate of less than 30%. Firstly, in terms of material preparation and precision machining costs, aluminum nitride powder is expensive, and its powder preparation and sintering processes are complex, making its material cost 5-8 times that of alumina powder. In the processing stage, the hardness and brittleness of aluminum nitride cause processing costs to account for more than 40% of the total cost, with a drilling yield of less than 60%. In contrast, alumina ceramics have low material preparation and processing costs, a wide process window, and production costs that are only 1 / 3 to 1 / 2 of those of aluminum nitride. Furthermore, in terms of the electrical properties of materials directly related to key characteristics of electrostatic chucks (such as electrostatic adsorption force and withstand voltage), some properties of aluminum nitride are inferior to those of alumina. For example, the band gap of aluminum nitride is 6.2 eV, less than that of alumina (8.7 eV), which makes its withstand voltage insulation performance inferior to that of alumina. The breakdown voltage of aluminum nitride is 15 kV / mm, less than that of alumina (18 kV / mm). Furthermore, aluminum nitride has a dielectric constant of 8.8, which is lower than that of aluminum oxide (9.8). This means that for electrostatic chuck dielectric layers of the same thickness, the electrostatic attraction of aluminum nitride dielectric layers is less than that of aluminum oxide dielectric layers. In terms of mechanical properties, aluminum nitride is hard and brittle, with lower toughness than aluminum oxide. Its bending strength is 350 MPa, lower than that of aluminum oxide (400 MPa), and its fracture toughness is 300-400 MPa, far less than that of aluminum oxide (920 MPa). Therefore, these numerous drawbacks of aluminum nitride materials have limited its commercialization in the semiconductor field. Summary of the Invention

[0004] In view of this, this application provides a multilayer composite ceramic disk and its preparation method, which can effectively improve the above-mentioned drawbacks of aluminum nitride as a material for manufacturing electrostatic chucks, such as high price and high processing cost.

[0005] This application provides a multilayer composite ceramic disk, including a first alumina structural layer and an aluminum nitride structural layer connected along the axial direction. The first alumina structural layer is provided with an adsorption electrode, and the aluminum nitride structural layer is provided with a heating electrode.

[0006] In one embodiment, the adsorption electrode is embedded within the first alumina structural layer; and / or, the heating electrode is embedded within the aluminum nitride structural layer.

[0007] In one embodiment, the composite connection method between the first alumina structural layer and the aluminum nitride structural layer includes: The adhesive is used for bonding, and the adhesive includes one or more of epoxy resin, silicone resin, polyurethane resin and acrylic resin, or the adhesive contains thermally conductive filler or inorganic filler. Alternatively, the connection can be made by metal film welding or pressure diffusion welding; Alternatively, it can be bonded using a ceramic-glass phase.

[0008] In one embodiment, the volume ratio of the aluminum nitride structural layer to the multilayer composite ceramic disk is less than or equal to 1 / 2.

[0009] In one embodiment, the multilayer composite ceramic disk further includes a second alumina structural layer, wherein the first alumina structural layer, the aluminum nitride structural layer, and the second alumina structural layer are sequentially composite-connected along the axial direction.

[0010] In one embodiment, the volume ratio of the aluminum nitride structural layer to the multilayer composite ceramic disk is less than or equal to 1 / 3.

[0011] In one embodiment, the composite connection method between the aluminum nitride structural layer and the second alumina structural layer includes: The adhesive is used for bonding, and the adhesive includes one or more of epoxy resin, silicone resin, polyurethane resin and acrylic resin, or the adhesive contains thermally conductive filler or inorganic filler. Alternatively, the connection can be made by metal film welding or pressure diffusion welding; Alternatively, it can be bonded using a ceramic-glass phase.

[0012] In one embodiment, the second alumina structural layer is provided with a functional electrode.

[0013] This application also provides a method for preparing a multilayer composite ceramic disk, the method comprising the following steps: S1: Prepare a first alumina structural layer with an adsorption electrode and an aluminum nitride structural layer with a heating electrode respectively; S2: The first alumina structural layer and the aluminum nitride structural layer are axially bonded together to obtain the multilayer composite ceramic disk.

[0014] This application also provides a method for preparing a multilayer composite ceramic disk, the method comprising the following steps: K1: Prepare a first alumina structural layer with an adsorption electrode, an aluminum nitride structural layer with a heating electrode, and a second alumina structural layer respectively. K2: The first alumina structural layer, the aluminum nitride structural layer and the second alumina structural layer are stacked and connected in sequence along the axial direction to obtain the multilayer composite ceramic disk.

[0015] In summary, this application provides a multilayer composite ceramic disk and its preparation method. Aluminum nitride, with its excellent thermal conductivity, is used as the heat transfer layer of the ceramic disk, while alumina, which is more cost-effective and exhibits better mechanical and electrical properties, is used as the adsorption surface medium layer, or simultaneously as both the adsorption surface medium layer and the substrate layer. The aluminum nitride heat transfer layer is sandwiched between the adsorption surface medium layer and the substrate layer. This design fully leverages the respective performance advantages of aluminum nitride and alumina, reducing the amount of aluminum nitride used. While ensuring excellent temperature uniformity of the ceramic disk, it also reduces costs, while possessing good adsorption performance and stable electrical insulation properties. This is an effective, stable, reliable, complementary, and cost-efficient technical structure. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a multilayer composite ceramic disc in one embodiment of this application.

[0017] Figure 2 This is a schematic diagram of the structure of a multilayer composite ceramic disc in another embodiment of this application.

[0018] Figure 3 This is a schematic flowchart of a method for preparing a multilayer composite ceramic disk in one embodiment of this application.

[0019] Figure 4 for Figure 3 A further flowchart illustrating the preparation method.

[0020] Figure 5 This is a schematic flowchart of a method for preparing a multilayer composite ceramic disk in another embodiment of this application.

[0021] Figure 6 for Figure 5 A further flowchart illustrating the preparation method.

[0022] Figure 7 This is a comparative test diagram of the surface temperature distribution of a single alumina ceramic disk.

[0023] Figure 8 This is a test diagram of the surface temperature distribution of the multilayer composite ceramic disk of this application.

[0024] Reference numerals: 10-Multilayer composite ceramic disk; 12-First alumina structural layer; 14-Aluminum nitride structural layer; 16-Adsorption electrode; 18-Heating electrode; 20-First composite surface; 22-Second composite surface; 24-Second alumina structural layer; 26-Third composite surface; 28-Fourth composite surface; 30-Adsorption surface; A-Axial direction; B-Planar direction. Detailed Implementation

[0025] Before describing the embodiments in detail, it should be understood that this application is not limited to the detailed structures or element arrangements described below or in the accompanying drawings. This application can be implemented in other ways. Furthermore, it should be understood that the wording and terminology used herein are for descriptive purposes only and should not be construed as limiting. The terms "comprising," "including," "having," and similar expressions used herein mean to include the items listed thereafter, their equivalents, and other additional items. In particular, when describing "an element," this application does not limit the number of elements to one, but may include multiple elements.

[0026] Existing electrostatic chucks are typically made solely of alumina ceramic or aluminum nitride ceramic. Alumina ceramic has poorer thermal conductivity than aluminum nitride ceramic. When electrostatic chucks need to perform both adsorption and heating functions, alumina ceramic can only provide excellent adsorption performance, but its poor thermal conductivity cannot guarantee the uniformity and stability of heating. Furthermore, alumina ceramic has advantages over aluminum nitride ceramic in terms of raw material cost, processing cost, mechanical properties, and electrical properties. Therefore, how to fully combine the performance advantages of alumina ceramic and aluminum nitride ceramic to obtain a novel material structure is a technical problem that urgently needs to be solved by those skilled in the art.

[0027] Please refer to Figure 1 As shown, this application provides a multilayer composite ceramic disk 10, which can be applied to semiconductor manufacturing devices such as electrostatic chucks and heaters. In this embodiment, the multilayer composite ceramic disk 10 is designed as a disc; in other embodiments, the multilayer composite ceramic disk 10 can also be other shapes. The multilayer composite ceramic disk 10 in this embodiment has a double-layer composite structure, including a first alumina structural layer 12 and an aluminum nitride structural layer 14 connected along the axial direction. The first alumina structural layer 12 is provided with an adsorption electrode 16, and the aluminum nitride structural layer 14 is provided with a heating electrode 18.

[0028] More specifically, the aforementioned axial direction refers to the axial direction A of the multilayer composite ceramic disk 10, which is the stacking and connection direction of the first alumina structural layer 12 and the aluminum nitride structural layer 14. The first alumina structural layer 12 has a first composite surface 20 perpendicular to the axial direction A, and the aluminum nitride structural layer 14 has a second composite surface 22 perpendicular to the axial direction A. The first composite surface 20 and the second composite surface 22 are compositely connected, and the surface of the first alumina structural layer 12 facing away from the aluminum nitride structural layer 14 forms an adsorption surface 30. The first alumina structural layer 12 is made of alumina ceramic material, and the aluminum nitride structural layer 14 is made of aluminum nitride ceramic material. In this application, only the aluminum nitride structural layer 14 is arranged as a heat transfer layer, while the remaining structures use alumina material as much as possible. This fully utilizes the performance and cost advantages of aluminum nitride and alumina while reducing the amount of aluminum nitride used, thus maximizing the integration of the performance advantages of aluminum nitride and alumina into the multilayer composite ceramic disk 10.

[0029] Furthermore, the adsorption electrode 16 is embedded within the first alumina structural layer 12, and the heating electrode 18 is embedded within the aluminum nitride structural layer 14. Preferably, the multilayer composite ceramic disk 10 has a planar direction B perpendicular to the axial direction A, and both the adsorption electrode 16 and the heating electrode 18 are laid out along the planar direction B. In this embodiment, the volume ratio of the aluminum nitride structural layer 14 to the multilayer composite ceramic disk 10 is less than or equal to 1 / 2, so as to minimize the amount of aluminum nitride used, thereby reducing costs while fully combining the performance advantages of aluminum nitride and alumina.

[0030] Please refer to Figure 2 As shown, this is another embodiment of the multilayer composite ceramic disk 10 of this application. In this embodiment, the multilayer composite ceramic disk 10 has a three-layer composite structure, including a first alumina structural layer 12, an aluminum nitride structural layer 14, and a second alumina structural layer 24. The first alumina structural layer 12, the aluminum nitride structural layer 14, and the second alumina structural layer 24 are sequentially connected in a composite manner along the axial direction. The first alumina structural layer 12 is provided with an adsorption electrode 16, and the aluminum nitride structural layer 14 is provided with a heating electrode 18.

[0031] More specifically, the aforementioned axial direction refers to the axial direction A of the multilayer composite ceramic disk 10, which is the stacking and connection direction of the first alumina structural layer 12, the aluminum nitride structural layer 14, and the second alumina structural layer 24. The first alumina structural layer 12 has a first composite surface 20 perpendicular to the axial direction A, and the aluminum nitride structural layer 14 has a second composite surface 22 perpendicular to the axial direction A. The first composite surface 20 and the second composite surface 22 are compositely connected. The aluminum nitride structural layer 14 has a third composite surface 26 opposite to the second composite surface 22, and the second alumina structural layer 24 has a fourth composite surface 28 perpendicular to the axial direction A. The third composite surface 26 and the fourth composite surface 28 are compositely connected. The surface of the first alumina structural layer 12 facing away from the aluminum nitride structural layer 14 forms an adsorption surface 30.

[0032] In this embodiment, the volume ratio of the aluminum nitride structural layer 14 to the multilayer composite ceramic disk 10 is less than or equal to 1 / 3, which can minimize the amount of aluminum nitride used and reduce costs while fully combining the performance advantages of aluminum nitride and aluminum oxide.

[0033] The second alumina structural layer 24 can be a single alumina ceramic material. In other embodiments, the second alumina structural layer 24 can also be provided with functional electrodes. The functional electrodes are embedded within the second alumina structural layer 24, for example, the alumina ceramic material and the functional electrodes can be integrally co-fired. The functional electrodes can be determined according to the actual application scenario of the multilayer composite ceramic disk 10. For scenarios with special application requirements, such as in physical vapor deposition processes, the functional electrodes can be radio frequency electrodes, but this application is not limited to this.

[0034] In this embodiment, the second alumina structural layer 24 is disposed on the side of the aluminum nitride structural layer 14 away from the first alumina structural layer 12, which can play a role in stabilizing the structure and further reduce the amount of aluminum nitride material used. At the same time, the opposite sides of the aluminum nitride are both alumina, which can avoid mechanical processing of aluminum nitride, such as grinding, polishing, drilling, etc., and avoid the problem of difficult processing caused by the hard and brittle properties of aluminum nitride.

[0035] In the above Figure 1 and Figure 2 In the illustrated embodiment, the composite connection between the first alumina structural layer 12 and the aluminum nitride structural layer 14, as well as the composite connection between the first alumina structural layer 12, the aluminum nitride structural layer 14, and the second alumina structural layer 24, can be varied. Specifically, the composite connection between the first composite surface 20 and the second composite surface 22, and between the third composite surface 26 and the fourth composite surface 28, can be considered as a composite connection between the alumina plane and the aluminum nitride plane, and can have various composite connection methods, including: The alumina plane and the aluminum nitride plane are connected by an adhesive, which may include one or more of epoxy resin, silicone resin, polyurethane resin, and acrylic resin. In some embodiments, thermally conductive fillers or other inorganic fillers may be added to the adhesive to enhance heat transfer performance and bonding strength. The adhesive is preferably an elastic silicone resin to absorb some of the stress, thereby reducing the interfacial stress caused by the matching coefficients of thermal expansion of alumina and aluminum nitride, and enhancing the structural strength of the connection between the alumina plane and the aluminum nitride plane.

[0036] Alumina planes and aluminum nitride planes can also be welded together using a metal thin film or a pressure diffusion welding method.

[0037] Alumina planes and aluminum nitride planes can also be bonded together using a ceramic glass phase.

[0038] It should also be noted that since alumina and aluminum nitride are materials with different properties, there will be certain interfacial stress when they are joined. Therefore, in this application, the composite method for joining the alumina plane and the aluminum nitride plane can be any method that can stably connect the two, provided that the joining method can effectively release the interfacial stress caused by the mismatch of the expansion coefficients of the alumina plane and the aluminum nitride plane, thereby improving the connection strength between the alumina plane and the aluminum nitride plane.

[0039] More specifically, this application can compositely connect an integrally sintered alumina structural layer with another integrally sintered aluminum nitride structural layer through a composite connection method. The aluminum nitride structural layer is arranged as a heat-conducting layer, and the alumina structural layer is arranged as a medium layer and a substrate layer for adsorption. The resulting composite stack structure combines the performance advantages and cost-effectiveness of both alumina and aluminum nitride. In the above composite structure, a heating electrode 18 is embedded inside the aluminum nitride structural layer 14. Heat is generated by applying current to the heating electrode 18. In principle, aluminum nitride only plays the role of heat transfer in the temperature generating layer. Due to the excellent thermal conductivity of aluminum nitride, the temperature of the aluminum nitride surface can be quickly homogenized in the planar direction B and diffused uniformly along the axial direction A of the stack structure to the adsorption surface 30 of the first alumina structural layer 12. The amount of aluminum nitride used in the composite stack structure should be as small as possible. An adsorption electrode 16 is embedded inside the first alumina structural layer 12. By applying voltage to the adsorption electrode 16, an electrostatic adsorption force is generated on the adsorption surface 30 to adsorb the wafer. The electrical insulation and dielectric properties of alumina are better than those of aluminum nitride, and it can more stably exert its electrostatic adsorption performance.

[0040] In some embodiments, the first alumina structural layer 12 and the aluminum nitride structural layer 14 are sintered into a whole by high-temperature integrated co-firing technology, and then the first alumina structural layer 12 and the aluminum nitride structural layer 14 are combined into a whole by connection technology, thereby forming a double-layer composite structure of the first alumina structural layer 12-alumina nitride structural layer 14.

[0041] In other embodiments, the first alumina structural layer 12 and the aluminum nitride structural layer 14 are sintered into a whole by high-temperature integrated co-firing technology, and the second alumina structural layer 24 is sintered separately to form a pure alumina layer. Alternatively, the second alumina structural layer 24 and a functional electrode are sintered into a whole by integrated co-firing technology, and then the first alumina structural layer 12, the aluminum nitride structural layer 14 and the second alumina structural layer 24 are combined into a whole by connection technology, thereby forming a three-layer composite structure of the first alumina structural layer 12-aluminum nitride structural layer 14-second alumina structural layer 24.

[0042] Please also refer to Figure 1 , Figure 3 and Figure 4 As shown, this application also provides a method for preparing a multilayer composite ceramic disk, the multilayer composite ceramic disk being, for example, a... Figure 1 The preparation method of the multilayer composite ceramic disk 10 with a double-layer composite structure in the embodiment shown includes the following steps: S1: Prepare a first alumina structural layer 12 with an adsorption electrode 16 and an aluminum nitride structural layer 14 with a heating electrode 18 respectively. S2: The first alumina structural layer 12 and the aluminum nitride structural layer 14 are axially bonded together to obtain... Figure 1 The multilayer composite ceramic disk 10 of the embodiment shown.

[0043] Step S1 further includes: S1.1: Prepare the first alumina precursor layer and the second alumina precursor layer of the first alumina structural layer 12, prepare the first aluminum nitride precursor layer and the second aluminum nitride precursor layer of the aluminum nitride structural layer 14, and prepare the precursor layers of the adsorption electrode 16 and the heating electrode 18 respectively. S1.2: The first alumina precursor layer, the precursor layer of the adsorption electrode 16 and the second alumina precursor layer are stacked in sequence and co-fired in an integrated manner to obtain the first alumina structural layer 12 with the adsorption electrode 16. The first aluminum nitride precursor layer, the precursor layer of the heating electrode 18 and the second aluminum nitride precursor layer are stacked in sequence and co-fired in an integrated manner to obtain the aluminum nitride structural layer 14 with the heating electrode 18.

[0044] More specifically, the preparation method includes: Preparation of the first alumina structural layer 12: A sheet-like ceramic blank is prepared using alumina ceramic powder. The sheet-like ceramic blank is pre-sintered at a pre-sintering temperature lower than the sintering temperature to obtain a pre-sintered ceramic part with a certain strength. After milling and surface grinding, the second alumina precursor layer is obtained. The precursor layer of the adsorption electrode 16 is formed by screen printing a conductor paste onto the upper surface of the second alumina precursor layer. The electrode film material of the adsorption electrode 16 can be a mixture of metal materials such as tungsten, molybdenum, nickel, and platinum with alumina ceramic materials. The first alumina precursor layer can be uniformly distributed alumina ceramic powder or a pre-formed, unsintered sheet-like alumina ceramic blank, preferably uniformly distributed alumina ceramic powder. The alumina ceramic powder is uniformly spread on the upper surface of the second alumina precursor layer, and the precursor layer of the adsorption electrode 16 is embedded inside the alumina ceramic powder and the second alumina precursor layer. After pressing and milling, the first alumina precursor layer is obtained. The first alumina precursor layer, the precursor layer of the adsorption electrode 16, and the second alumina precursor layer are sequentially arranged from top to bottom and co-fired under pressure in a sintering apparatus. After sintering, the first alumina structural layer 12 is obtained. The side of the first alumina precursor layer facing away from the second alumina precursor layer forms the adsorption surface 30, and the side of the second alumina precursor layer facing away from the first alumina precursor layer forms the first composite surface 20.

[0045] Preparation of aluminum nitride structural layer 14: A sheet-like ceramic blank is prepared using aluminum nitride ceramic powder. The sheet-like ceramic blank is pre-sintered at a pre-sintering temperature lower than the sintering temperature to obtain a pre-sintered ceramic part with a certain strength. After milling and surface grinding, the second aluminum nitride precursor layer is obtained. The precursor layer of heating electrode 18 is formed by screen printing a conductor paste onto the upper surface of the second aluminum nitride precursor layer. The electrode film material of heating electrode 18 can be a mixture of metal materials such as tungsten, molybdenum, nickel, and platinum with aluminum nitride ceramic material. The first aluminum nitride precursor layer can be uniformly distributed aluminum nitride ceramic powder or a pre-formed, unsintered sheet-like aluminum nitride ceramic blank, preferably uniformly distributed aluminum nitride ceramic powder. Aluminum nitride ceramic powder is evenly spread on the upper surface of the second aluminum nitride precursor layer. The precursor layer of the heating electrode 18 is embedded inside the aluminum nitride ceramic powder and the second aluminum nitride precursor layer. After pressing and milling, the first aluminum nitride precursor layer is obtained. The first aluminum nitride precursor layer, the precursor layer of the heating electrode 18, and the second aluminum nitride precursor layer are arranged sequentially from top to bottom and co-fired together under pressure in a sintering device. After sintering, the aluminum nitride structural layer 14 is obtained. The side of the first aluminum nitride precursor layer facing away from the second aluminum nitride precursor layer forms the second composite surface 22.

[0046] The first composite surface 20 and the second composite surface 22 are bonded together with silicone resin to obtain the desired product. Figure 1The embodiment shown is a multilayer composite ceramic disk 10 with a double-layer composite structure.

[0047] Please also refer to Figure 2 , Figure 5 and Figure 6 As shown, this application also provides a method for preparing a multilayer composite ceramic disk, the multilayer composite ceramic disk being, for example, a... Figure 2 The multilayer composite ceramic disk 10 with a three-layer composite structure shown in the embodiment is prepared by the following steps: K1: Prepare a first alumina structural layer 12 with an adsorption electrode 16, an aluminum nitride structural layer 14 with a heating electrode 18, and a second alumina structural layer 24 respectively. K2: The first alumina structural layer 12, the aluminum nitride structural layer 14, and the second alumina structural layer 24 are sequentially stacked and connected along the axial direction to obtain... Figure 2 The multilayer composite ceramic disk 10 of the embodiment shown.

[0048] Step K1 further includes: K1.1: Prepare the first alumina precursor layer and the second alumina precursor layer of the first alumina structural layer 12, prepare the first aluminum nitride precursor layer and the second aluminum nitride precursor layer of the aluminum nitride structural layer 14, and prepare the precursor layers of the second alumina structural layer 24, the adsorption electrode 16 and the heating electrode 18 respectively. K1.2: The first alumina precursor layer, the precursor layer of the adsorption electrode 16 and the second alumina precursor layer are stacked in sequence and co-fired to obtain the first alumina structural layer 12 with the adsorption electrode 16. The first aluminum nitride precursor layer, the precursor layer of the heating electrode 18 and the second aluminum nitride precursor layer are stacked in sequence and co-fired to obtain the aluminum nitride structural layer 14 with the heating electrode 18. The precursor layer of the second alumina structural layer 24 is sintered to obtain the second alumina structural layer 24.

[0049] The specific preparation method of the multilayer composite ceramic disk 10 in this embodiment can refer to the above embodiment. The difference is that a second alumina structural layer 24 needs to be sintered separately. The side of the second aluminum nitride precursor layer away from the first aluminum nitride precursor layer is formed as the third composite surface 26, and one side of the second alumina structural layer 24 is formed as the fourth composite surface 28. The first composite surface 20 and the second composite surface 22, as well as the third composite surface 26 and the fourth composite surface 28, are bonded together with silicone resin. They can be bonded simultaneously or in stages to obtain the desired product. Figure 2 The embodiment shown is a three-layer composite ceramic disk 10 with a multilayer composite structure.

[0050] Electrostatic chucks require excellent adsorption performance and efficient, stable thermal control. Please also refer to... Figure 7 and Figure 8As shown, taking an 8-inch wafer carrier electrostatic chuck as an example, a comparative test was conducted on its thermal control capabilities, with 78℃±1℃ as the standard surface temperature and a power output of 30W.

[0051] like Figure 7 As shown, the test sample is an electrostatic chuck made of single alumina material (single alumina ceramic disc). When the surface temperature of the single alumina ceramic disc reaches the predetermined temperature control point of 78°C, the lowest temperature displayed at position P2 is 72.9°C, which is 5.1°C different from the standard temperature control temperature.

[0052] like Figure 8 As shown, the test sample is the multilayer composite ceramic disk 10 of this application, specifically... Figure 1 In the embodiment shown, the multilayer composite ceramic disk 10 with a two-layer alumina-alumina composite structure has a minimum temperature of 77.5°C when the surface of the multilayer composite ceramic disk 10 reaches the predetermined temperature control point of 78°C. This is only 0.5°C lower than the temperature control standard temperature, which meets the product standard.

[0053] In the above tests, the actual thermal conductivity of alumina used by the inventors was 30 W / (mK), and the actual thermal conductivity of aluminum nitride was 170 W / (mK). The time required to heat a single alumina ceramic disk to 78°C was four times that of the alumina-alumina nitride composite ceramic disk (multi-layer composite ceramic disk 10). Therefore, the alumina-alumina nitride composite ceramic disk (multi-layer composite ceramic disk 10) of this application exhibits significantly superior thermal control performance compared to a single alumina ceramic disk.

[0054] In summary, this application provides a multilayer composite ceramic disk and its preparation method. Aluminum nitride, with its excellent thermal conductivity, is used as the heat transfer layer of the ceramic disk, while alumina, which is more cost-effective and exhibits better mechanical and electrical properties, is used as the adsorption surface medium layer, or simultaneously as both the adsorption surface medium layer and the substrate layer. The aluminum nitride heat transfer layer is sandwiched between the adsorption surface medium layer and the substrate layer. This design fully leverages the respective performance advantages of aluminum nitride and alumina, reducing the amount of aluminum nitride used. While ensuring excellent temperature uniformity of the ceramic disk, it also reduces costs, while possessing good adsorption performance and stable electrical insulation properties. This is an effective, stable, reliable, complementary, and cost-efficient technical structure.

[0055] The concepts described herein may be implemented in other forms without departing from their spirit and characteristics. The specific embodiments disclosed should be considered illustrative rather than restrictive. Therefore, the scope of this application is determined by the appended claims, and not by the preceding description. Any changes within the literal meaning and equivalent scope of the claims should fall within the scope of those claims.

Claims

1. A multi-layer composite ceramic disc, characterized in that, It includes a first alumina structural layer (12) and an aluminum nitride structural layer (14) that are compositely connected along the axial direction. The first alumina structural layer (12) is provided with an adsorption electrode (16), and the aluminum nitride structural layer (14) is provided with a heating electrode (18).

2. The multi-layer composite ceramic disk as described in claim 1, characterized in that, The adsorption electrode (16) is embedded in the first alumina structural layer (12); and / or, the heating electrode (18) is embedded in the aluminum nitride structural layer (14).

3. The multi-layer composite ceramic disc as described in claim 1, characterized in that, The composite connection method between the first alumina structural layer (12) and the aluminum nitride structural layer (14) includes: The adhesive is used for bonding, and the adhesive includes one or more of epoxy resin, silicone resin, polyurethane resin and acrylic resin, or the adhesive contains thermally conductive filler or inorganic filler. Alternatively, the connection can be made by metal film welding or pressure diffusion welding; Alternatively, it can be bonded using a ceramic-glass phase.

4. The multilayer composite ceramic disc as described in any one of claims 1-3, characterized in that, The volume ratio of the aluminum nitride structural layer (14) to the multilayer composite ceramic disk (10) is less than or equal to 1 / 2.

5. The multilayer composite ceramic disc as described in any one of claims 1-3, characterized in that, The multilayer composite ceramic disk (10) further includes a second alumina structural layer (24), wherein the first alumina structural layer (12), the aluminum nitride structural layer (14) and the second alumina structural layer (24) are sequentially composite connected along the axial direction.

6. The multi-layer composite ceramic disk as described in claim 5, characterized in that, The volume ratio of the aluminum nitride structural layer (14) to the multilayer composite ceramic disk (10) is less than or equal to 1 / 3.

7. The multilayer composite ceramic disc as described in claim 5, characterized in that, The composite connection method between the aluminum nitride structural layer (14) and the second alumina structural layer (24) includes: The adhesive is used for bonding, and the adhesive includes one or more of epoxy resin, silicone resin, polyurethane resin and acrylic resin, or the adhesive contains thermally conductive filler or inorganic filler. Alternatively, the connection can be made by metal film welding or pressure diffusion welding; Alternatively, it can be bonded using a ceramic-glass phase.

8. The multilayer composite ceramic disc as described in claim 5, characterized in that, The second alumina structure layer (24) is provided with functional electrodes.

9. A method for preparing a multilayer composite ceramic disk, characterized in that, The preparation method includes the following steps: S1: Prepare a first alumina structural layer (12) with an adsorption electrode (16) and an aluminum nitride structural layer (14) with a heating electrode (18), respectively. S2: The first alumina structural layer (12) and the aluminum nitride structural layer (14) are axially bonded together to obtain the multilayer composite ceramic disk (10).

10. A method for preparing a multilayer composite ceramic disk, characterized in that, The preparation method includes the following steps: K1: Prepare a first alumina structural layer (12) with an adsorption electrode (16), an aluminum nitride structural layer (14) with a heating electrode (18), and a second alumina structural layer (24). K2: The first alumina structural layer (12), the aluminum nitride structural layer (14) and the second alumina structural layer (24) are stacked and connected in sequence along the axial direction to obtain the multilayer composite ceramic disk (10).

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