Electrostatic chuck and method of manufacturing the same

Abstract

The application discloses an electrostatic chuck, which comprises a ceramic base body, wherein the ceramic base body is embedded with an electrostatic electrode and a heating electrode, the electrostatic electrode and the heating electrode have a height difference in the ceramic base body, and the ceramic base body and the electrostatic electrode and the heating electrode are integrally sintered. The application further discloses a preparation method of the electrostatic chuck. Compared with the prior art, the electrostatic chuck has the advantages that the heating electrode and the electrostatic electrode are embedded in the ceramic base body and integrally sintered, the material size difference and internal structure deterioration caused by multiple sintering are avoided, the electrostatic chuck can realize partition heating and temperature control, the heating efficiency is high, and the temperature uniformity is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrostatic chuck, in particular to an electrostatic chuck and a preparation method thereof. BACKGROUND

[0002] The electrostatic chuck is a device that uses electrostatic adsorption principle to adsorb the wafer to be processed on its surface and can control the wafer surface temperature by back blowing gas. In the integrated circuit manufacturing process, especially in the etching process, in order to avoid the phenomenon of wafer movement or misalignment, which leads to the process cannot be carried out normally, the electrostatic chuck is usually used to fix and support the wafer. With the uniformity of critical dimension value becoming more and more important, the temperature uniformity and temperature control functionality of the electrostatic chuck are expected to increase.

[0003] In the prior art, the ceramic part with adsorption function and the heating part with heating function of the electrostatic chuck are manufactured separately and then bonded together by using glue. The heating part itself can accurately control the temperature. The heating part of the electrostatic chuck is composed of a resin sheet clamping a heating electrode. It is found in practice that the surface radial temperature difference of the electrostatic chuck is obvious. Moreover, the resin sheet is easily corroded and damaged in the long-term service in the vacuum high-corrosion environment, even if various means are used to improve the damage degree, the effect is not obvious.

[0004] In the prior art, in order to solve the defects of radial temperature difference and easy corrosion and damage caused by the resin sheet, the ceramic material is used to replace the resin sheet, the heating electrode is embedded in the ceramic material, and the heating ceramic part is sintered to form a heating ceramic part, and then bonded and integrated with the ceramic part with adsorption function. It is found that the electrostatic chuck has poor heat conductivity and insufficient temperature conduction rate after a period of service. Moreover, after the wafer processing is completed, the wafer cannot be effectively detached due to the high temperature of the surface of the electrostatic chuck. SUMMARY

[0005] The present application aims to provide an electrostatic chuck with high temperature rise efficiency and high temperature uniformity.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] An electrostatic chuck comprises a ceramic base, the ceramic base is embedded with an electrostatic electrode and a heating electrode, the electrostatic electrode and the heating electrode have a height difference in the ceramic base, and the ceramic base and the electrostatic electrode and the heating electrode are sintered together at one time.

[0008] The inventor has found through research that the main reason for the insufficient temperature conduction rate and low temperature control precision of the electrostatic chuck in the prior art after a period of service is that the ceramic part with heating function and the ceramic part with adsorption function are integrated by bonding, and the adhesive layer is separated due to the limited thermal fatigue resistance of the adhesive; at the same time, the poor thermal conductivity of the bonding material causes the insufficient temperature conduction rate and low temperature control precision. Therefore, the inventor has made a new type of electrostatic chuck by embedding the electrostatic electrode and the heating electrode in the same ceramic substrate and sintering them at one time, which not only overcomes the defect of poor resistance to plasma corrosion caused by using resin as the substrate of the heating part, but also overcomes the defect of slow temperature conduction rate caused by the low thermal conductivity of the bonding adhesive, and the temperature of the electrostatic chuck is uniform and controllable, and it is suitable for environments with high corrosive gas and large density plasma.

[0009] Further, the heating electrodes are a plurality of heating electrodes, and the plurality of heating electrodes are distributed in the same height plane in the ceramic substrate. In this preferred embodiment, the plurality of heating electrodes refers to at least two heating electrodes, and the electrostatic chuck containing a plurality of heating electrodes is sintered at one time, which can avoid the excessive size difference and internal organization deterioration caused by multiple sintering, meet the requirement of uniformity of critical dimensions, and further ensure the quality of the electrostatic chuck.

[0010] Further, the plurality of heating electrodes do not intersect with each other. Since each heating electrode does not intersect with each other, each heating electrode can be controlled independently, so that the electrostatic chuck has a plurality of temperature control regions. Specifically, each heating electrode is independently connected to a heating control device, and the control device can independently control the temperature of each heating electrode.

[0011] Further, the heating electrodes are in the form of coils, and the plurality of heating electrodes form a group of concentric circles in the ceramic substrate. The heating electrodes can be printed into various patterns such as spiral and coil shape by conductive paste. In this preferred embodiment, the heating electrodes in the form of coils can effectively transfer heat to the surface of the electrostatic chuck. The plurality of heating electrodes are independently controlled, and thus a group of concentric circle patterns are formed.

[0012] Further, the electrostatic chuck further comprises a metal substrate, the metal substrate is provided with a fluid channel, and the metal substrate is bonded below the heating electrodes of the ceramic substrate.

[0013] Further, a heat resistance layer is further arranged between the ceramic substrate and the metal substrate. The heat resistance layer is bonded between the ceramic substrate and the metal substrate by adhesive.

[0014] Further, the heating electrode is a tungsten electrode with titanium component added, and the titanium component is 0.001-10% in mass percentage. The heating electrode can be selected from tungsten electrode, molybdenum electrode, titanium electrode, niobium electrode or tungsten carbide electrode. In the present preferred solution, the tungsten electrode with titanium component added is selected, and the titanium component is 0.001-10% in mass percentage, so that the temperature control of the electrostatic chuck is more accurate, and the diffusion of the electrode is reduced. Since the main component of the heating electrode is W, and the addition of Ti in W can improve the difference between the thermal expansion coefficient of pure W and the ceramic, the high-temperature diffusion of W is inhibited, so that the thermal deformation of the heating electrode region and the surrounding region during the service of the heating component can be improved, and the heating electrode and the ceramic are easy to combine during sintering, and the deformation degree of the whole electrode is reduced.

[0015] Further, the electrostatic electrode is selected from tungsten electrode, molybdenum electrode, titanium electrode, tungsten carbide electrode and the like. The electrostatic electrode is in a grid shape, and the contact area with the ceramic matrix is reduced without affecting the electrostatic adsorption. The electrostatic electrode layer is uniform and has small deformation, so that the qualified rate of one-time sintering is ensured.

[0016] Another object of the present application is to provide a preparation method of the electrostatic chuck, which comprises the following steps:

[0017] S1: providing a ceramic blank;

[0018] S2: coating or printing an electrostatic electrode layer on the upper surface of the ceramic blank;

[0019] S3: coating or printing a heating electrode layer on the lower surface of the ceramic blank;

[0020] S4: providing a ceramic green sheet;

[0021] S5: stacking the layers in the order of ceramic green sheet, ceramic blank with the electrostatic electrode layer and the heating electrode layer coated or printed thereon, and ceramic green sheet from top to bottom;

[0022] S6: one-time sintering and forming by vacuum hot pressing.

[0023] Further, CaO or CaF2 or MgF2 sintering aids are added in the sintering and forming process to prevent deformation during sintering.

[0024] Further, the sintering temperature is 1200-1500℃, the sintering pressure is 5-40Mpa, and the sintering atmosphere is non-oxidizing atmosphere. Since the thermal expansion coefficients of metal materials and ceramic materials are high, the sintering temperature is easy to change, so that the sintering temperature is controlled in the range of 1200-1500℃, so that the sintering deformation can be prevented.

[0025] Compared with the prior art, the present application has the following advantages:

[0026] The heating electrode and electrostatic electrode of the present invention are embedded in the ceramic matrix and sintered in one step, thus avoiding the material size difference and internal structure deterioration caused by multiple sintering, realizing zoned heating and temperature control, and achieving high heating efficiency and high temperature uniformity.

[0027] The electrostatic chuck and its manufacturing method of the present invention are further described below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic structural diagram of an electrostatic chuck according to an embodiment of the present invention;

[0029] Figure 2 Schematic diagram of the structure of the heating electrode of the electrostatic chuck according to Example 1 of the present invention;

[0030] Figure 3 Schematic diagram of the structure of the heating electrode of the electrostatic chuck according to Example 2 of the present invention;

[0031] Figure 4 Schematic diagram of the structure of the heating electrode of the electrostatic chuck according to Example 3 of the present invention;

[0032] Figure 5 A schematic diagram of a preparation method according to an embodiment of the present invention;

[0033] Figure 6 The present invention is a flow chart of a preparation method according to one embodiment of the present invention. DETAILED DESCRIPTION

[0034] like Figure 1 As shown, the electrostatic chuck of the present invention includes a ceramic substrate 10, in which an electrostatic electrode 11 and a heating electrode 12 are embedded. The electrostatic electrode 11 and the heating electrode 12 have a height difference in the ceramic substrate 10, and the ceramic substrate 10, the electrostatic electrode 11, and the heating electrode 12 are sintered in one step.

[0035] Specifically, there are multiple heating electrodes 12, and the multiple heating electrodes 12 do not intersect with each other, so that the multiple heating electrodes 12 can be independently heated and temperature-controlled to form multiple different temperature-controlled zones on the surface of the electrostatic chuck. Each heating electrode 12 can be independently temperature-controlled by connecting each heating electrode 12 to a heating control device (not shown). The heating electrodes 12 are distributed at the same height plane within the ceramic substrate 10, so that each temperature-controlled zone is located on the same plane, thereby facilitating temperature uniformity control in each temperature-controlled zone.

[0036] Please also refer to Figure 2In the embodiment, the heating electrode 12 is in the shape of a coil. Of course, the heating electrode 12 can also be in the shape of a spiral or other patterns. In the embodiment, the heating electrode 12 is in the shape of a coil, which can effectively transfer heat to the surface of the electrostatic chuck. The plurality of heating electrodes 12 are independently temperature-controlled and located at the same height, thus forming a group of concentric circle patterns. The heating electrode 12 can be selected from tungsten electrode, molybdenum electrode, titanium electrode, niobium electrode or tungsten carbide electrode. In the embodiment, the heating electrode is selected from tungsten electrode with titanium component, and the titanium component is 0.001-10% by mass percentage, which can make the temperature control of the electrostatic chuck more accurate and reduce the diffusion of the electrode. Since the main component of the heating electrode is W, and the addition of Ti in W can improve the difference between the thermal expansion coefficient of pure W and the ceramic, the high-temperature diffusion of W can be inhibited, thus the thermal deformation of the heating electrode region and the surrounding region during the service of the heating component can be improved, and the heating electrode and the ceramic are easy to combine during sintering, and the deformation degree of the whole electrode is reduced.

[0037] The electrostatic electrode 11 is in the shape of a grid, which can reduce the contact area with the ceramic base 10 without affecting the electrostatic adsorption. The electrostatic electrode 11 layer is uniform and has small deformation, which ensures the qualified rate of one-time sintering. The electrostatic electrode 11 can be selected from tungsten electrode, molybdenum electrode, titanium electrode, tungsten carbide electrode and the like.

[0038] The electrostatic chuck further comprises a metal base 20, and the metal base 20 is provided with a fluid channel 21. The surface of the metal base 20 is subjected to insulation treatment. The fluid channel 21 is used for supplying heat transfer medium to the surface of the electrostatic chuck. The fluid channel 21 is provided in plurality, and the plurality of fluid channels 21 are spaced apart from each other. The metal base 20 is bonded to the ceramic base 10 by using glue. Specifically, the surface of the metal base 20 is coated with glue, and then the bottom surface of the heating electrode 12 of the ceramic base 10 is pressed against the surface of the metal base 20 coated with glue.

[0039] In order to prevent the heat of the heating electrode 11 in the ceramic base 10 from being transferred to the metal base 20, a heat resistance layer 30 is further arranged between the ceramic base 10 and the metal base 20. Similarly, the heat resistance layer 30 is also used to bond the ceramic base 10 and the metal base 20 by using glue. Therefore, there are a bonding layer 41 and a bonding layer 42 above and below the heat resistance layer 30, respectively. The heat resistance layer 30 is preferably made of heat resistance material with a thermal conductivity <0.1 W / m.k, such as colloidal material made of silicone glue, silicone rubber, phenolic resin glue, polyurethane glue, acrylic glue and the like.

[0040] Please refer to Figure 3 , Figure 6 The preparation method of the electrostatic chuck of the present application specifically comprises the following steps:

[0041] 1) Preparation of ceramic slurry

[0042] Take 0.1-1 micron alumina ceramic particles as raw material, purity ≥ 99.9%, take alumina ceramic particles as the measurement base, add 5wt.% or less CaO or CaF2 or MgF2 as sintering aid, add 1wt.% or less dispersant, 5wt.% or less binder and 3wt.% or less plasticizer, the rest is solvent, solid content is 45%-60%, ball milling for 24h, make uniform dispersed ceramic slurry. Solvent can be selected from toluene, xylene, ethanol, isopropanol, ethylene glycol, etc., dispersant can be selected from polyacrylic acid, fatty acid, fish oil, etc., binder can be selected from polyethylene, ethyl cellulose, PVB, etc., plasticizer selected from PEG, PVA, CMC and PVAC, etc., can be added alone, also can be two combinations, no special limitation.

[0043] 2) Forming

[0044] Forming means can be selected from dry pressing forming, flow forming, grouting forming, hot pressure casting and other forming methods, ceramic slurry is made into ceramic blank 10a, preferably flow forming. After drying and cutting, the ceramic blank is drilled.

[0045] 3) Electrode making

[0046] Add W powder, Ti powder and polymer to make conductive slurry; the polymer at least includes a solvent, and conventional conductive slurry additives such as dispersant and surfactant can also be added, and the solvent can be selected from ethanol. Among them, the mass of Ti powder is 0.001-10% of the total mass of conductive slurry. Print or coat the electrostatic electrode on the upper surface of the ceramic blank, and print or coat the heating electrode on the lower surface of the same ceramic blank. The electrostatic electrode is grid-shaped, the electrode thickness is 5-10 microns, and the electrode shape is circular, cross-shaped, etc. The heating electrode is coil-shaped, and the thickness is 10-20 microns. The resistance value of the electrode is designed to be 20-50 ohms.

[0047] 4) Laminating

[0048] Please refer to Figure 5 Place a ceramic blank 13, 14 on the upper and lower surfaces of the ceramic blank 10a with the electrostatic electrode 11 and the heating electrode 12 respectively, and press the superimposed laminated body.

[0049] 5) Debinding

[0050] The ceramic blank is dried in the atmosphere, debinded at 400-600°C, and pre-fired at 700-1000°C to form a laminated body with certain strength. The atmosphere for pre-firing is a non-oxidizing atmosphere to remove organic matter inside the electrode and ceramic.

[0051] 6) Pressure sintering

[0052] The sintering temperature is selected as 1200-1500 DEG C, the deformation cannot be controlled and the internal structure is deteriorated at too high sintering temperature, the sintering pressure is selected as 5-40 MPa, and the sintering atmosphere is non-oxidizing atmosphere.

[0053] 7) Machining

[0054] The ceramic sintered body after sintering is processed by using a diamond grinding wheel to plane grind, adjust the thickness of the ceramic sintered body, polish the surface to reduce the roughness of the ceramic surface, and at the same time, the side surface is ground to reach the required size accuracy, and according to the actual situation, the electrode hole is continuously repaired.

[0055] In the application, the electrostatic chuck device can contain multiple heating areas, each area is independently temperature-controlled, and according to the actual application process needs, the voltage or current size of each area is adjusted or the existing mature temperature adjustment mode is used to adjust the temperature. Compared with the non-partition electrostatic chuck, the temperature is easy to control, and the temperature uniformity is higher.

[0056] In the application, after the lamination, one-time pressure sintering is adopted to avoid position movement and deformation caused by multiple sintering. At the same time, a sintering aid is added to the ceramic material, compared with pure alumina ceramic sintering, the sintering temperature of the ceramic is effectively reduced, and the internal structure is prevented from deteriorating before the ceramic sintering is dense. Compared with the traditional pressureless atmosphere sintering, the pressure sintering can more effectively inhibit the meridian deformation and provide additional ceramic sintering power.

[0057] In the application, the electrode material is treated specially, Ti powder is added to W to inhibit the diffusion of W into the ceramic interior at high temperature sintering, and at the same time, the resistivity and the thermal expansion coefficient of W can be adjusted, the interface thermal stress between the ceramic and the metal in the process of pressure sintering is reduced, and the phenomenon of serious deformation or ceramic cracking in the sintering process is avoided, and the yield is improved.

[0058] Example 1

[0059] 1) Preparation of ceramic blank

[0060] 1 μm spherical alumina ceramic particles are used as raw materials, the purity is greater than or equal to 99.9%, 0.5wt.% or less CaO and 3wt.% MgF2 are added as sintering aids, taking the weight of the ceramic particles as the measurement basis, ethanol is used as a solvent, 0.8wt.% polyacrylic acid is added as a dispersant, 2.5wt.% PVB is added as a binder, and 3wt.% PEG is added as a plasticizer, the solid content is adjusted to 55%, ball milling is carried out for 24 hours, ceramic slurry with uniform dispersion is prepared, ceramic blank is formed by flow casting, and the ceramic blank is drilled.

[0061] 2) Electrode manufacturing

[0062] W powder, 5wt.% Ti powder and polymer were added to make a conductive slurry, and the electrostatic electrode was printed on the upper surface of a ceramic green body, and the heating electrode was printed on the lower surface of the same ceramic green body. The electrostatic electrode was grid-shaped, the electrode thickness was 15 μm, and the electrode shape was circular. The heating electrode was coil-shaped, and the thickness was 15 μm. Please refer to Figure 1 and Figure 2 In this embodiment, the resistance value of the heating electrode 12 is designed to be 40 ohms, and the heating area is 4 areas 12a, 12b, 12c, and 12d.

[0063] 3) Laminating

[0064] A layer of ceramic green body without printed electrodes was placed on the upper surface and lower surface of the ceramic green body printed with electrostatic electrodes and heating electrodes, respectively, and then stacked in turn to form a laminated body.

[0065] 4) Debinding

[0066] The ceramic green body was dried in an atmospheric atmosphere, debound at 600°C for 30 min, and pre-fired at 1000°C to form a laminated body with a certain strength. The pre-firing atmosphere is a non-oxidizing atmosphere to remove organic matter inside the electrode and ceramic.

[0067] 5) Pressure sintering

[0068] The sintering temperature is preferably 1500°C, and a too high sintering temperature cannot control the deformation and deteriorates the internal structure. The sintering pressure is selected to be 10 MPa, and the sintering atmosphere is a non-oxidizing atmosphere.

[0069] 6) Machining

[0070] The ceramic sintered body after sintering is processed by using a diamond grinding wheel for flat grinding, adjusting the thickness of the ceramic sintered body, polishing the surface to reduce the roughness of the ceramic surface, and grinding the side surface to achieve the required dimensional accuracy. According to the actual situation, the electrode hole is further repaired.

[0071] Example 2

[0072] 1) Preparation of ceramic green body

[0073] 0.5 μm spherical alumina ceramic particles were used as raw materials, the purity was ≥99.9%, 1wt.% CaO and 2wt.% MgF2 were added as sintering aids based on the weight of the ceramic particles as the measurement basis, anhydrous ethanol was used as the solvent, 0.8wt.% polyacrylic acid was added as the dispersant, 2.5wt.% PVB was added as the binder, and 3wt.% PEG was added as the plasticizer, the solid content was adjusted to 60%, and the ceramic slurry was prepared by ball milling for 24 h. The ceramic green body was formed by tape casting and drilled.

[0074] 2) Electrode making

[0075] W powder, 10wt.% Ti powder and polymer were added to make a conductive slurry, and the electrostatic electrode was printed on the upper surface of a ceramic green body, and the heating electrode was printed on the lower surface of the same ceramic green body. The electrostatic electrode was in a grid shape, the thickness of the electrode was 10 μm, and the electrode shape was circular. The heating electrode was in a coil shape, and the thickness was 20 μm. Please refer to Figure 1 and Figure 3 In this embodiment, the resistance value of the heating electrode 12 was designed to be 30 ohms, and the heating area was three areas 12a, 12b and 12c.

[0076] 3) Laminating

[0077] A layer of ceramic green body without printed electrodes was placed on the upper surface and lower surface of the ceramic green body printed with the electrostatic electrode and the heating electrode, respectively, and then stacked in sequence to press and form a laminated body.

[0078] 4) Debinding

[0079] The ceramic green body was dried in an atmospheric atmosphere, debound at 580°C for 30 min, and pre-fired at 1000°C to form a laminated body with a certain strength. The atmosphere for pre-firing is a non-oxidizing atmosphere to remove organic matter inside the electrode and ceramic.

[0080] 5) Pressure sintering

[0081] The sintering temperature is preferably 1300°C, and a too high sintering temperature cannot be controlled and the internal organization is deteriorated. The sintering pressure is selected to be 30 Mpa, and the sintering atmosphere is a non-oxidizing atmosphere.

[0082] 6) Machining

[0083] The ceramic sintered body after sintering is processed by using a diamond grinding wheel for flat grinding, adjusting the thickness of the ceramic sintered body, polishing the surface to reduce the roughness of the ceramic surface, and grinding the side surface to achieve the required dimensional accuracy. According to the actual situation, the electrode hole is further repaired.

[0084] Example 3

[0085] 1) Ceramic green body preparation

[0086] 0.1 μm spherical alumina ceramic particles were used as raw materials, the purity was ≥99.9%, 2wt.% CaO and 3wt.% MgF2 were added as sintering aids based on the weight of the ceramic particles as the measurement basis, ethylene glycol was used as the solvent, 0.5wt.% polyacrylic acid was added as the dispersant, 2.5wt.% PVB was added as the binder, and 1.5wt.% PEG was added as the plasticizer, the solid content was adjusted to 45%, and the ceramic slurry was uniformly dispersed by ball milling for 24 h. The ceramic green body was prepared by flow casting, and the ceramic green body was drilled.

[0087] 2) Electrode fabrication

[0088] W powder, 1 wt.% Ti powder, and a polymer were mixed to form a conductive slurry. An electrostatic electrode was printed on the upper surface of a ceramic green body in a grid pattern with a thickness of 5 μm and a circular shape. A heating electrode was printed on the lower surface of the same ceramic green body in a coil pattern with a thickness of 10 μm. See FIG. 1. Figure 1 and Figure 4 The resistance of the heating electrode 12 was designed to be 20 ohms, and the heating area was two areas 12a, 12b.

[0089] 3) Lamination

[0090] A layer of ceramic green body without printed electrodes was placed on the upper and lower surfaces of the ceramic green body with printed electrostatic and heating electrodes, respectively, and stacked in order to press and form a laminated body.

[0091] 4) Debinding

[0092] The ceramic green body was dried in an atmospheric atmosphere, debound at 550°C for 30 min, and pre-fired at 1000°C to form a laminated body with a certain strength. The pre-firing atmosphere was a non-oxidizing atmosphere to remove organic matter inside the electrode and ceramic.

[0093] 5) Pressure sintering

[0094] The sintering temperature was preferably 1200°C, and a too high sintering temperature could not control the deformation and deteriorate the internal structure. The sintering pressure was selected to be 40 MPa, and the sintering atmosphere was a non-oxidizing atmosphere.

[0095] 6) Machining

[0096] The ceramic sintered body after sintering was processed by flat grinding with a diamond grinding wheel to adjust the thickness of the ceramic sintered body, polished the surface to reduce the roughness of the ceramic surface, and the side surface was ground to achieve the required dimensional accuracy. According to the actual situation, the electrode hole was further repaired.

[0097] Performance test of Example 4

[0098] The effects of the above three factors on the heating efficiency, temperature uniformity, and shape of the electrostatic chuck were compared in terms of the Ti powder addition amount, forming method, sintering temperature control, and temperature zone.

[0099] Control group 1

[0100] The difference from Example 1 was that the forming method was different: in this control group experiment, Ti powder was not added to the electrode slurry, and the process parameters for sintering and forming were consistent. The result was that the electrode W diffused significantly into the ceramic, affecting the heating effect.

[0101] Control group 2

[0102] The difference from example 1 is that the forming method is different: in this control group experiment, 12% Ti powder is added to the electrode slurry, and the process parameters for sintering and forming are consistent. The result is that the electrode W diffuses significantly into the ceramic, and part of it cracks.

[0103] Control group 3

[0104] The difference from example 1 is that: in this control group experiment, the ceramic base of the electrostatic electrode and the ceramic base with heating electrode are sintered and formed respectively, and then the two parts are bonded together with glue, and the process parameters for sintering and forming are consistent. The result is that the temperature rise rate is significantly reduced, and the bonding layer cracks after a period of use.

[0105] Control group 4

[0106] The difference from example 2 is that: in this control group experiment, sintering above 1600℃ is used, with a setting of 1650℃, and other parameters are consistent with comparative example 1. The result is that the sintered electrostatic chuck ceramic is tested by metallography, and the internal organization is coarse, overburned, and the deformation is more than 0.3mm.

[0107] Control group 5

[0108] The difference from example 3 is that: the electrostatic chuck does not have temperature control zoning. The result is that the surface temperature uniformity of the electrostatic chuck deteriorates, and the difference between the center and the edge of a Φ300mm electrostatic chuck is higher than 20℃.

[0109] The process parameters and test results of example 1, example 2, example 3 and control group 1 to 5 are as follows:

[0110]

[0111]

[0112] The above examples only describe the preferred embodiments of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. An electrostatic chuck, characterized by: The electrostatic chuck comprises a ceramic base, a static electrode and a heating electrode embedded in the ceramic base, the static electrode and the heating electrode have a height difference in the ceramic base, and the ceramic base and the static electrode and the heating electrode are sintered together; the heating electrode is a tungsten electrode with titanium component, the titanium component accounts for 0.001-10% in mass percentage; the heating electrode is in the form of a coil, and a plurality of the heating electrodes form a group of concentric circles in the ceramic base.

2. The electrostatic chuck of claim 1, wherein: The heating electrode is in the form of a coil, and a plurality of the heating electrodes are distributed in the same height plane in the ceramic base.

3. The electrostatic chuck of claim 2, wherein: The heating electrodes do not intersect with each other.

4. The electrostatic chuck of claim 1, wherein: The electrostatic chuck further comprises a metal base provided with a fluid channel, and the metal base is bonded below the heating electrode of the ceramic base.

5. The electrostatic chuck of claim 1, wherein: A heat resistance layer is further arranged between the ceramic base and the metal base.

6. The method of producing an electrostatic chuck according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: providing a ceramic blank; applying or printing a static electrode layer on the upper surface of the ceramic blank; applying or printing a heating electrode layer on the lower surface of the ceramic blank; providing a ceramic green sheet; stacking the ceramic green sheet, the ceramic blank with the applied or printed static electrode layer and heating electrode layer, and the ceramic green sheet in the order from top to bottom; sintering together by vacuum hot pressing.

7. The method of claim 6, wherein: CaO or CaF2 or MgF2 sintering aids are added in the sintering process.

8. The method of claim 6, wherein: The sintering temperature is 1200-1500℃, the sintering pressure is 5-40Mpa, and the sintering atmosphere is a non-oxidizing atmosphere.

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