Electrostatic chuck and semiconductor device

Abstract

The present invention provides an electrostatic chuck and semiconductor equipment, belonging to the field of semiconductor preparation technology. The present application connects a charge generator to a pin assembly. When a wafer needs to be desorbed on the electrostatic chuck, the charge generator is started. Due to the residual positive charge on the upper surface of the dielectric layer, the set charge generated by the charge generator is a negative charge, and the charge generator conducts the generated negative charge to the pin assembly. When the pin assembly lifts the wafer, the pin assembly is covered with negative charges, and the negative charges and the positive charges on the upper surface of the dielectric layer cancel each other out, thereby reducing the adsorption force between the wafer and the electrostatic chuck, so that the wafer and the electrostatic chuck can be desorbed better during the desorption process, avoiding the situation where the wafer and the electrostatic chuck cannot be desorbed smoothly to cause the wafer to be damaged, and solves the technical problem of poor charge removal in the J-R type electrostatic chuck in the prior art, which causes the wafer to be damaged during the desorption process.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor preparation, and in particular relates to an electrostatic chuck and semiconductor equipment. Background Art

[0002] Electrostatic chucks play a vital role in multiple stages of the semiconductor manufacturing process. Modern semiconductor manufacturing involves wafer cleaning, oxidation, photolithography, etching, and deposition, each of which involves multiple steps. Ion doping, ion implantation, physical vapor deposition (PVD), and chemical vapor deposition (CVD) all require stable wafer fixation, necessitating electrostatic chucks for clamping.

[0003] According to the different adsorption principles, electrostatic chucks can be divided into Coulomb type and JR type (Johnsen-Rahbeck type). Among them, the Coulomb type electrostatic chuck uses insulating material as the dielectric layer. There are no freely movable electrons in it, and an electrostatic attraction is formed between the wafer and the electrode through polarized charge. Its advantage is that the residual electrostatic force is easy to eliminate, and its disadvantage is that the electrostatic force is relatively small. The dielectric layer of the JR type electrostatic chuck is conductive, so when the electrode is energized, the negative charge of the dielectric layer will accumulate on the lower surface of the dielectric layer, and the positive charge will accumulate on the upper surface of the dielectric layer, and form countless tiny electric fields on the contact surface, thereby adsorbing the workpiece. Its advantage is that the electrostatic adsorption force is large, and its disadvantage is that it is sensitive to the roughness of the chuck surface and is not easy to desorb.

[0004] In the prior art, since the surface roughness of the JR type electrostatic chuck is relatively sensitive, when the static electricity is poorly removed, the wafer is affected by the stress generated by the residual static electricity, resulting in the wafer and the electrostatic chuck being unable to be completely desorbed and the wafer being damaged. Summary of the Invention

[0005] The embodiments of the present invention provide an electrostatic chuck and a semiconductor device, aiming to solve the technical problem in the prior art that poor static removal in a JR-type electrostatic chuck leads to breakage during wafer desorption.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is to provide an electrostatic chuck and a semiconductor device.

[0007] In a first aspect, an embodiment of the present invention provides an electrostatic chuck, comprising a chuck base, an ejector pin assembly, and a charge generator. The chuck base is used to place a wafer, and the chuck base is provided with a hollow chamber, which is connected to the upper surface of the chuck base; the ejector pin assembly is disposed in the hollow chamber, and has the freedom to move up and down along the height direction of the chuck base, and is used to lift the wafer placed on the chuck base; the charge generator is electrically connected to the ejector pin assembly, and is used to generate a set charge;

[0008] The electrical properties of the set charges are opposite to the electrical properties of the charges on the upper surface of the dielectric layer.

[0009] The solution shown in the embodiment of the present application is compared with the prior art. The present application connects a charge generator to a pin assembly. When the wafer needs to be desorbed from the electrostatic chuck, the charge generator is activated. Due to the residual positive charge on the upper surface of the dielectric layer, the set charge generated by the charge generator is a negative charge. The charge generator conducts the generated negative charge to the pin assembly. When the pin assembly lifts the wafer, the pin assembly is covered with negative charges. The negative charges and the positive charges on the upper surface of the dielectric layer cancel each other out, thereby reducing the adsorption force between the wafer and the electrostatic chuck, making it easier to desorb the wafer from the electrostatic chuck, and avoiding the situation where the wafer cannot be desorbed smoothly from the electrostatic chuck, which causes the wafer to be damaged. This solves the technical problem of poor charge removal in the JR type electrostatic chuck in the prior art, which causes the wafer to be damaged during desorption.

[0010] In conjunction with the first aspect, in one possible implementation, the ejector pin assembly includes an ejector pin and a drive structure. The ejector pin is vertically disposed within the hollow chamber, having the freedom to move up and down along the height direction of the chuck base, and is used to lift a wafer placed on the chuck base. The ejector pin is connected to the charge generator and is used to transmit a set charge generated by the charge generator to the ejector pin. The drive structure is disposed below the ejector pin and is fixed within the hollow chamber, and is used to drive the ejector pin to move up and down.

[0011] In conjunction with the first aspect, in one possible implementation, the hollow chamber includes a first chamber and a second chamber. The first chamber is disposed above and communicates with the second chamber, and the aperture of the first chamber is smaller than that of the second chamber. The bottom of the first chamber and the top of the second chamber form a limiting surface. The drive structure further includes a coil and a power supply. The coil is vertically disposed within the second chamber, and the ejector pin is movably disposed within the coil. The power supply is connected to the coil.

[0012] In combination with the first aspect, in a possible implementation, a vent is provided inside the ejector pin and a plurality of vents are provided on the outer wall of the ejector pin, and the vent is communicated with the vent; the electrostatic chuck further includes an air pipe, a plasma generator and an air pump; the plasma generator is used to generate plasma with a set charge; the air outlet of the air pipe is communicated with the air vent, the air inlet of the air pipe is communicated with the air outlet of the air pump, and the air inlet of the air pump is communicated with the air outlet of the plasma generator; the air pipe is communicated with the air vent for adjusting the position of the ejector pin under the driving control of the gas, and for transmitting the plasma with a set charge generated by the plasma generator into the vent.

[0013] In conjunction with the first aspect, in one possible implementation, the ejector includes a tip and a body. The top of the tip is a concave structure, and a plurality of fixing blocks are provided on the top surface of the concave structure, and the plurality of fixing blocks are arranged at equal intervals along the central axis of the tip. The tip is fixedly connected to the body, and the vent is provided within the body along the length of the body and communicates with the tip. The plurality of vents are provided along the central axis of the body, and the vents communicate with each other. One end of the vent is connected to the air outlet of the air pipe.

[0014] In combination with the first aspect, in a possible implementation, an annular limiting portion is further provided on the top body; the outer diameter of the annular limiting portion is larger than the inner hole diameter of the first chamber, and the upper surface of the annular limiting portion is used to contact and connect with the limiting surface, and an insulating buffer layer is provided on the limiting surface.

[0015] In combination with the first aspect, in a possible implementation, a position detection component is provided in the hollow chamber, and the position detection component is used to detect the position of the ejector assembly in the chuck base; the position detection component includes at least two position detection elements, the two position detection elements are a first position detection element and a second position detection element, the first position detection element is provided on the limiting surface, the second position detection element is provided on the side wall of the second chamber, and the second position detection element is provided between the limiting surface and the top surface of the coil.

[0016] In combination with the first aspect, in a possible implementation, when static electricity is completely eliminated, the ejector pin is 1.5 mm to 3.0 mm higher than the surface of the chuck base.

[0017] With reference to the first aspect, in a possible implementation, the ejector pin assembly includes at least three ejector pins, and the three ejector pins are not on the same straight line.

[0018] In a second aspect, an embodiment of the present invention further provides a semiconductor device comprising the electrostatic chuck involved in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the structure of an electrostatic chuck according to an embodiment of the present invention when adsorbing a wafer;

[0020] Figure 2 for Figure 1 A magnified view of the local A area;

[0021] Figure 3 It is a structural cross-sectional view of the ejector pin;

[0022] Figure 4 for Figure 3 Enlarged view of the local B area;

[0023] Figure 5 A schematic diagram of the connection structure between the ejector pin and the trachea provided in an embodiment of the present invention;

[0024] Figure 6 for Figure 5 A magnified view of the local C area;

[0025] Description of reference numerals:

[0026] 1. Chuck base; 11. Hollow chamber; 110. First chamber; 111. Second chamber; 112. Limiting surface;

[0027] 2. Ejector pin assembly; 21. Ejector pin; 221. Coil; 23. Vent hole; 24. Vent hole; 211. Ejector pin; 212. Ejector body; 213. Annular stopper; 25. Fixing block;

[0028] 3. Charge generator; 5. Trachea;

[0029] 4. Position detection component; 41. First position detection element; 42. Second position detection element. DETAILED DESCRIPTION

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] It should be further explained that the drawings and implementation methods of the present invention mainly describe the concept of the present invention. On the basis of this concept, the specific forms and settings of some connection relationships, positional relationships, power mechanisms, power supply systems, hydraulic systems and control systems may not be fully described. However, on the premise that those skilled in the art understand the concept of the present invention, those skilled in the art can implement the above-mentioned specific forms and settings in a well-known manner.

[0032] When an element is referred to as being “fixed to” or “disposed on” another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it can be directly connected to the other element or indirectly connected to the other element.

[0033] The directions or positional relationships indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0034] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being referred to. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "plurality" means two or more, and "several" means one or more, unless otherwise specifically defined.

[0035] Please also refer to Figures 1 to 4 , an electrostatic chuck and semiconductor device provided by the present invention are now described.

[0036] An electrostatic chuck includes a chuck base 1, an ejector pin assembly 2, and a charge generator 3. The chuck base 1 is used to hold a wafer and is provided with a hollow chamber 11, which is connected to the upper surface of the chuck base 1. The ejector pin assembly 2 is disposed within the hollow chamber 11 and has the freedom to move up and down along the height of the chuck base 1. The ejector pin assembly 2 is used to lift the wafer placed on the chuck base 1. The charge generator 3 is electrically connected to the ejector pin assembly 2 and is used to generate a set charge. The set charge has an electrical property opposite to that of the charge on the upper surface of the dielectric layer.

[0037] The present embodiment provides an electrostatic chuck. Compared with the prior art, the present application connects a charge generator 3 to a pin assembly 2. When the wafer needs to be desorbed from the electrostatic chuck, the charge generator 3 is activated. Due to the residual positive charge on the upper surface of the dielectric layer, the set charge generated by the charge generator 3 is a negative charge, and the charge generator 3 conducts the generated negative charge to the pin assembly 2. When the pin assembly 2 lifts the wafer, the pin assembly 2 is covered with negative charges, and the negative charges and the positive charges on the upper surface of the dielectric layer cancel each other out, thereby reducing the adsorption force between the wafer and the electrostatic chuck, allowing the wafer to be desorbed better during the desorption process, avoiding the situation where the wafer cannot be desorbed smoothly from the electrostatic chuck, which causes the wafer to be damaged. This solves the technical problem of poor charge removal in the prior art JR-type electrostatic chuck, which causes the wafer to be damaged during the desorption process.

[0038] In some embodiments, the ejector pin assembly 2 may adopt the structure shown in the figure. Figure 3 , the ejector assembly 2 includes:

[0039] Ejector assembly 2 includes ejector pin 21 and a drive mechanism. Ejector pin 21 is vertically positioned within hollow chamber 11 and is free to move up and down along the height of chuck base 1. It is used to lift a wafer placed on chuck base 1. Ejector pin 21 is connected to charge generator 3 and is used to transfer the set charge generated by charge generator 3 to ejector pin 21. The drive mechanism is positioned below ejector pin 21 and is fixed within hollow chamber 11. It is used to drive ejector pin 21 in its vertical movement.

[0040] When the wafer needs to be desorbed from the electrostatic chuck, the driving structure is first started, and the driving structure drives the ejector pin 21 to move along the vertical direction of the chuck base 1, so that the tip of the ejector pin 21 is higher than the upper surface of the chuck base 1, thereby lifting the wafer from the electrostatic chuck. During the lifting process, the charge generator 3 is started at the same time, and the charge generator 3 generates negative charge, and then the negative charge is transferred to the ejector pin 21. When the ejector pin 21 lifts the wafer, since the ejector pin 21 is covered with negative charges, the negative charges and the positive charges on the upper surface of the dielectric layer cancel each other out, thereby reducing the adsorption force between the wafer and the electrostatic chuck, so that the wafer and the electrostatic chuck can be better desorbed, and the wafer and the electrostatic chuck cannot be desorbed smoothly, which avoids the situation where the wafer is damaged.

[0041] In some embodiments, the hollow chamber 11 includes a first chamber 110 and a second chamber 111. The first chamber 110 is located above the second chamber 111, and the first chamber 110 and the second chamber 111 are connected. The aperture of the first chamber 110 is smaller than the aperture of the second chamber 111. The bottom of the first chamber 110 and the top of the second chamber 111 constitute a limiting surface 112. The driving structure also includes a coil 221 and a power supply. The coil 221 is vertically arranged in the second chamber 111, and the ejector pin 21 is movably inserted into the coil 221. The power supply is connected to the coil 221. The limiting surface 112 is used to limit the movement range of the ejector pin 21.

[0042] When the power is turned on, coil 221 generates a magnetic field under the action of the current. At this time, the ejector pin 21 moves away from coil 221 under the action of the magnetic field, thereby lifting the wafer. At the same time, the setting of the limit surface 112 can prevent the ejector pin 21 from moving too much and causing damage to the wafer. The present application only needs to control the power on and off to control the lifting and lowering movement of the ejector pin 21, thereby achieving the purpose of lifting the wafer. At the same time, due to the strict environmental requirements of wafer preparation, remote control of wafer lifting can also be achieved.

[0043] Workers can control the intensity of the magnetic field by controlling the current supplied by the power supply, thereby controlling the different movement speeds of the ejector pins 21, thereby being suitable for the ejection and desorption of wafers of different specifications.

[0044] Based on the above embodiment, ejector pin 21 is provided with an internal vent 23 and multiple vents 24 on its outer wall, which are connected to vent 23. The electrostatic chuck also includes an air pipe 5, a plasma generator, and an air pump. The plasma generator is used to generate plasma with a set charge. The outlet of air pipe 5 is connected to vent 23, the inlet of air pipe 5 is connected to the outlet of the air pump, and the inlet of the air pump is connected to the outlet of the plasma generator. The air pipe 5 is connected to the vent 23 to adjust the position of ejector pin 21 under gas drive control and to transfer the plasma with a set charge generated by the plasma generator into the vent 23.

[0045] Among them, the air pump and plasma generator are both connected to the control system signal.

[0046] Since the ejector pin 21 is in local point contact with the wafer when it lifts the wafer, when the negative charge on the ejector pin 21 and the positive charge on the dielectric layer are eliminated, the positive charge around the ejector pin 21 is eliminated first. When the positive charge is too far away from the ejector pin 21, the negative charge cannot eliminate the positive charge. Therefore, the present application also includes an air pipe 5, a plasma generator and an air pump. The air pump and the plasma generator are started. The plasma generator is used to generate a plasma with a set charge. The air pump blows the plasma with a set charge generated by the plasma generator into the ejector pin 21 through the air pipe 5, and finally blows it through the air holes 23 set inside the ejector pin 21 and through the multiple air holes 24 set on the outer wall of the ejector pin 21 to the upper surface of the chuck base 1, thereby eliminating the positive charge on the dielectric layer as a whole, and preventing the residual positive charge from affecting the normal desorption between the wafer and the electrostatic chuck, thereby causing wafer damage.

[0047] At the same time, plasma can also prevent particles from accumulating around the wafer. The specific principle is as follows: the ions generated by wireless radio frequency (RF) can confine the particles suspended in the process chamber (the particles themselves are not charged, but have electrical properties after combining with gas molecules) to the ions, preventing them from falling onto the wafer and surrounding parts before the process begins. This can improve the static removal efficiency and improve the wafer yield.

[0048] See also Figure 5 and Figure 6 Furthermore, the ejector pin 21 includes a tip 211 and a body 212. The top of the tip 211 is a concave structure, and a plurality of fixing blocks 25 are provided on the top surface of the concave structure. The plurality of fixing blocks 25 are arranged at equal intervals along the central axis of the tip 211. The tip 211 is fixedly connected to the body 212. A vent 23 is provided in the body 212 along the length direction of the body 212 and is connected to the tip 211. A plurality of vents 24 are provided around the side of the central axis of the body 212. The vents 24 are connected to the vent 23. One end of the vent 23 is connected to the air outlet of the trachea 5.

[0049] Since the air holes 23 are connected to the concave structure of the top 211, and since a plurality of fixed blocks 25 are provided at intervals around the top surface of the concave structure, two adjacent fixed blocks 25 have guide gaps. Since the arrangement of the air holes 24 is relatively sparse relative to the arrangement of the fixed blocks 25, when plasma is blown, the plasma flows out through the gaps between the fixed blocks 25, and the flow rate through the air holes 24 is greater than the flow rate through the guide gaps. Therefore, the closer the air pressure is to the wafer, the greater the pressure is, and the closer the air pressure is to the air holes 24, the smaller the pressure is, so that the plasma flowing out of the gap flows toward the air holes 24, thereby forming a negative pressure under the wafer, thereby preventing the wafer from shifting in position when the ejector pin 21 lifts the wafer. At the same time, the plasma airflow can also blow the entire surface of the wafer, so that an airflow layer is formed between the wafer and the ejector pin 21, so that the wafer can be desorbed conveniently and quickly.

[0050] On the basis of the above embodiment, an annular limiting portion 213 is further provided on the top body 212; the outer diameter of the annular limiting portion 213 is larger than the inner hole diameter of the first chamber 110, and the upper surface of the annular limiting portion 213 is used to contact and connect with the limiting surface 112, and an insulating buffer layer is provided on the limiting surface 112.

[0051] The annular limiting portion 213 can limit the movement of the ejector pin 21 , and the insulating buffer layer can prevent the chuck base 1 from being charged during long-term use, thereby affecting the lifting and lowering movement of the ejector pin 21 .

[0052] Furthermore, a position detection assembly 4 is provided in the hollow chamber 11, and the position detection assembly 4 is used to detect the position of the ejector assembly 2 in the chuck base 1; the position detection assembly 4 includes at least two position detection elements, the two position detection elements are a first position detection element 41 and a second position detection element 42, the first position detection element 41 is provided on the limiting surface 112, the second position detection element 42 is provided on the side wall of the second chamber 111, and the second position detection element 42 is provided between the limiting surface 112 and the top surface of the coil 221.

[0053] The position detection component 4 is connected to the control system.

[0054] When the first position detection element 41 transmits the signal that the ejector 21 is detected and the signal that the second position detection element 42 does not detect the ejector 21 to the control system, the control system determines that the ejector 21 is in the ejection action, and the air pump, plasma generator, and power supply operate uniformly for a specified time under the action of the control system. After running for the specified time, the control system controls the power supply, air pump, air pump, and plasma generator to shut down, so that the ejector 21 falls into the coil 221 under the action of its own gravity. At this time, the control system receives the signal that the first position detection element 41 does not detect the ejector 21 and the second position detection element 42 detects the ejector 21, so that it can be determined that the ejector 21 has completed the ejection movement and is in the initial state.

[0055] Specifically, there are multiple position detection components 4 , and the multiple position detection components 4 are arranged at intervals in the hollow chamber 11 .

[0056] Optionally, when static electricity is completely eliminated, the ejector pin 21 is 1.5 mm to 3.0 mm above the surface of the chuck base 1 .

[0057] On the basis of the above embodiment, there are multiple ejector pin assemblies 2 , and the multiple ejector pin assemblies 2 are arranged on the chuck base 1 .

[0058] Specifically, the ejector pin assembly 2 includes at least three ejector pins 21, and the three ejector pins 21 are not aligned. Because three points not aligned must form a common circle, when two adjacent ejector pin assemblies 2 are used to lift a wafer, the three non-aligned ejector pins 21 form a raised circular surface, thereby ensuring stability and improving safety during the wafer desorption process.

[0059] In a second aspect, an embodiment of the present invention further provides a semiconductor device comprising the electrostatic chuck involved in the first aspect.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An electrostatic chuck, characterized in that: include: A chuck base (1) for placing a wafer, the chuck base (1) being provided with a hollow chamber (11), the hollow chamber (11) being in communication with the upper surface of the chuck base (1); A pin assembly (2) is disposed in the hollow chamber (11), the pin assembly (2) having the freedom to move up and down along the height direction of the chuck base (1), and the pin assembly (2) is used to lift a wafer placed on the chuck base (1); A charge generator (3) is electrically connected to the ejector assembly (2), and the charge generator (3) is used to generate a set charge; The electrical properties of the set charges are opposite to the electrical properties of the charges on the upper surface of the dielectric layer.

2. The electrostatic chuck according to claim 1, wherein The ejector pin assembly (2) comprises: A ejector pin (21) is vertically arranged in the hollow chamber (11), and the ejector pin (21) has the freedom to move up and down along the height direction of the chuck base (1). The ejector pin (21) is used to lift the wafer placed on the chuck base (1); the ejector pin (21) is connected to the charge generator (3) and is used to conduct the set charge generated by the charge generator (3) to the ejector pin (21); A driving structure is provided below the ejector pin (21), the driving structure being fixed in the hollow chamber (11), and the driving structure being used to drive the ejector pin (21) to move up and down.

3. The electrostatic chuck according to claim 2, wherein: The hollow chamber (11) includes a first chamber (110) and a second chamber (111), wherein the first chamber (110) is arranged above the second chamber (111), and the first chamber (110) is communicated with the second chamber (111), and the aperture of the first chamber (110) is smaller than the aperture of the second chamber (111); the bottom of the first chamber (110) and the top of the second chamber (111) form a limiting surface (112); the driving structure further includes: A coil (221) is vertically arranged in the second chamber (111), and the ejector pin (21) is movably arranged in the coil (221); A power source is connected to the coil (221).

4. The electrostatic chuck according to claim 3, wherein: The ejector pin (21) is provided with an air vent (23) inside and a plurality of air vents (24) are provided on the outer wall of the ejector pin (21), and the air vent (24) is connected to the air vent (23); the electrostatic chuck further comprises an air pipe (5), a plasma generator and an air pump; the plasma generator is used to generate plasma with a set charge; the air outlet of the air pipe (5) is connected to the air vent (23), the air inlet of the air pipe (5) is connected to the air outlet of the air pump, and the air inlet of the air pump is connected to the air outlet of the plasma generator; the air pipe (5) is connected to the air vent (23) for adjusting the position of the ejector pin (21) under the driving control of the gas, and is also used to transmit the plasma with a set charge generated by the plasma generator to the air vent (23).

5. The electrostatic chuck according to claim 4, wherein: The ejector pin (21) comprises: A top (211), wherein the top of the top (211) is a concave structure, and a plurality of fixing blocks (25) are provided on the top surface of the concave structure, and the plurality of fixing blocks (25) are arranged at equal intervals around the central axis of the top (211); The top body (212) is fixedly connected to the top body (212), the vent hole (23) is arranged in the top body (212) along the length direction of the top body (212) and is connected to the vent hole (211), and a plurality of vent holes (24) are arranged around the central axis of the top body (212), and the vent holes (24) are connected to the vent holes (23); one end of the vent hole (23) is connected to the air outlet of the air pipe (5).

6. The electrostatic chuck according to claim 5, wherein: An annular limiting portion (213) is also provided on the top body (212); the outer diameter of the annular limiting portion (213) is larger than the inner diameter of the first chamber (110); the upper surface of the annular limiting portion (213) is used to contact and connect with the limiting surface (112); and an insulating buffer layer is provided on the limiting surface (112).

7. The electrostatic chuck according to claim 6, wherein: A position detection assembly (4) is provided in the hollow chamber (11), and the position detection assembly (4) is used to detect the position of the ejector assembly (2) in the chuck base (1); the position detection assembly (4) includes at least two position detection elements, the two position detection elements being a first position detection element (41) and a second position detection element (42), the first position detection element (41) being provided on the limiting surface (112), the second position detection element (42) being provided on the side wall of the second chamber (111), and the second position detection element (42) being provided between the limiting surface (112) and the top surface of the coil (221).

8. The electrostatic chuck according to claim 7, wherein When the static electricity is completely removed, the ejector pin (21) is 1.5 mm to 3.0 mm above the surface of the chuck base (1).

9. The electrostatic chuck according to claim 2, wherein: The ejector pin assembly (2) comprises at least three ejector pins (21), and the three ejector pins (21) are not on the same straight line.

10. A semiconductor device, characterized in that: The invention comprises an electrostatic chuck according to any one of claims 1 to 9.

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