Uniform heat dissipation type ceramic electrostatic chuck

Abstract

The uniform heat dissipation type ceramic electrostatic chuck comprises a chuck body and a plurality of electrostatic electrodes evenly embedded in the chuck body, the chuck body is made of ceramic materials, the side, close to the top, of the interior of the chuck body is of a hollow structure to form a ventilation cavity, and a movable plate slides on the inner wall of the ventilation cavity; a plurality of ejector pin pipes are uniformly and fixedly arranged in the movable plate, all the ejector pin pipes slide on the top side of the suction cup and are of hollow structures, and a first cooling medium flows in the ventilation cavity; a plurality of cooling pipes are uniformly and fixedly arranged in the sucker and below the electrostatic electrode, and a second cooling medium flows in the cooling pipes. Through the above structure, heat of a contact surface is taken away by using high thermal conductivity of helium, gas flows between the bottom of a wafer and the top of the chuck to enhance heat dissipation so as to improve the thermal stability of the electrostatic chuck, continuous heat exchange is realized through an external circulating pump in cooperation with the cooling pipe, and stable temperature of the chuck is maintained through gas-liquid synergistic heat dissipation. And the stability in the machining process is ensured.

Description

Technical Field

[0001] This utility model relates to the field of electrostatic chuck technology, and in particular to a uniform heat dissipation ceramic electrostatic chuck. Background Technology

[0002] Traditional wafer clamping methods, such as mechanical clamping and paraffin bonding, were once widely used in the machinery industry, but they easily damage the wafer, leading to wafer warping and contamination, severely affecting processing accuracy. With technological advancements, vacuum chucks made of porous ceramics have gradually emerged, using the negative pressure created between the silicon wafer and the ceramic surface to hold the wafer. However, this method can cause localized wafer deformation, affecting its flatness. In recent years, ceramic electrostatic chucks have become the ideal choice for clamping ultra-thin wafers due to their stable and uniform adsorption force, non-contamination characteristics, and effective temperature control of the silicon wafer.

[0003] Traditional ceramic electrostatic chucks, when operating at high power or for extended periods, suffer from uneven wafer heating due to localized heat accumulation, affecting processing accuracy and yield. Existing technologies largely rely on the thermal conductivity of a single ceramic substrate, lacking active heat dissipation structures, and the electrode distribution may exacerbate temperature gradients, failing to effectively balance uniform heat dissipation and stable electrostatic adsorption. Therefore, this invention provides a uniformly heat-dissipating ceramic electrostatic chuck to address the problems mentioned in the background. Utility Model Content

[0004] The purpose of this invention is to provide a uniformly heat-dissipating ceramic electrostatic chuck. It utilizes the high thermal conductivity of helium to remove heat from the contact surface. The gas flows between the bottom of the wafer and the top of the chuck to enhance heat dissipation and improve the thermal stability of the electrostatic chuck. In conjunction with a cooling pipe and an external circulation pump, continuous heat exchange is achieved. The gas-liquid synergistic heat dissipation helps maintain a stable temperature of the chuck and ensures stability during the processing.

[0005] To achieve the above objectives, a uniform heat dissipation ceramic electrostatic chuck is provided, comprising a chuck and a plurality of electrostatic electrodes uniformly embedded inside the chuck. The chuck is made of ceramic material, and the inside of the chuck and the side near the top are provided with a hollow structure to form a venting cavity. A movable plate slides on the inner wall of the venting cavity, and a plurality of ejector pins are uniformly fixed inside the movable plate. The ejector pins slide on the top side of the chuck and are all hollow. A first cooling medium flows inside the venting cavity.

[0006] Multiple cooling tubes are uniformly fixed inside the suction cups below the electrostatic electrodes, and a second cooling medium flows inside the cooling tubes.

[0007] According to the uniform heat dissipation ceramic electrostatic chuck, the top of the chuck is provided with multiple flow channels, which are connected to the ejector pin tube.

[0008] According to the uniform heat dissipation ceramic electrostatic chuck, an air inlet pipe communicating with the ventilation cavity is fixed inside the chuck, and the first cooling medium is helium.

[0009] According to the uniform heat dissipation ceramic electrostatic chuck, both ends of the cooling pipe are fixed with a connecting pipe, and the second cooling medium is water.

[0010] According to the uniform heat dissipation ceramic electrostatic chuck, a cylinder is fixedly installed in the middle of the chuck, the piston rod of the cylinder moves inside the chuck and is fixed with the movable plate, and a sealing sleeve is fixedly installed inside the chuck and on the side near the cylinder, which is sleeved on the outside of the piston rod.

[0011] According to the uniform heat dissipation ceramic electrostatic chuck, a sealing ring is fixed on the outer ring of the movable plate, and the sealing ring is slidably connected to the surface of the ventilation cavity.

[0012] According to the uniform heat dissipation ceramic electrostatic chuck, the chuck is made of aluminum nitride ceramic material.

[0013] This utility model has the following beneficial effects:

[0014] 1. Compared with existing technologies, helium gas is uniformly diffused to the bottom of the wafer through the ejector pin tube. The high thermal conductivity of helium gas carries away heat from the contact surface, thereby cooling the wafer. A flow channel is formed in conjunction with the flow path, allowing gas to flow between the bottom of the wafer and the top of the chuck, enhancing heat dissipation and improving the thermal stability of the electrostatic chuck.

[0015] 2. Compared with existing technologies, the cooling pipe is embedded in the aluminum nitride ceramic matrix. The high thermal conductivity of aluminum nitride is used to transfer the heat generated in the electrode area to the water. The water is continuously circulated by an external pump to achieve heat exchange, which helps to maintain the stable temperature of the suction cup and ensures the stability of the processing. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0017] Figure 1 This is a first-view structural schematic diagram of the uniform heat dissipation ceramic electrostatic chuck of this utility model;

[0018] Figure 2 This is a second-view structural diagram of the uniform heat dissipation ceramic electrostatic chuck of this utility model;

[0019] Figure 3 This is a cross-sectional view of the uniform heat dissipation ceramic electrostatic chuck of this utility model.

[0020] Figure 4 This is a schematic diagram of the internal cross-sectional structure of the uniform heat dissipation ceramic electrostatic chuck of this utility model.

[0021] Legend:

[0022] 1. Suction cup; 2. Vent chamber; 3. Movable plate; 4. Cylinder; 5. Ejector tube; 6. Flow channel; 7. Electrostatic electrode; 8. Cooling pipe; 9. Connecting pipe; 10. Sealing ring; 11. Air inlet pipe. Detailed Implementation

[0023] This section will describe in detail the specific embodiments of the present utility model. The preferred embodiments of the present utility model are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present utility model, but they should not be construed as limiting the scope of protection of the present utility model.

[0024] Reference Figure 1-4 This utility model embodiment of a uniform heat dissipation ceramic electrostatic chuck includes a chuck 1 and multiple electrostatic electrodes 7 uniformly embedded inside the chuck 1. The chuck 1 is made of ceramic material. The inside of the chuck 1 and the side near the top are hollow to form a ventilation cavity 2. A movable plate 3 slides on the inner wall of the ventilation cavity 2. Multiple ejector pins 5 are uniformly fixed inside the movable plate 3. The ejector pins 5 all slide on the top side of the chuck 1 and are all hollow. A first cooling medium flows inside the ventilation cavity 2. An air inlet pipe 11 communicating with the ventilation cavity 2 is fixed inside the chuck 1. The first cooling medium is helium. Multiple flow channels 6 are provided on the top of the chuck 1, and the flow channels 6 communicate with the ejector pins 5.

[0025] When the wafer enters the etching chamber, the ejector pin 5 rises to receive the wafer for transport. Then, the ejector pin 5 falls, placing the wafer on the surface of the electrostatic chuck. Helium gas is injected into the venting chamber 2 through the inlet pipe 11 as a cooling medium. The helium gas diffuses evenly to the bottom of the wafer through the ejector pin 5, utilizing its high thermal conductivity to remove heat from the contact surface and cool the wafer. This, combined with the flow channel 6, forms a flow channel, allowing gas to flow between the bottom of the wafer and the top of the chuck 1, enhancing heat dissipation and improving the thermal stability of the electrostatic chuck.

[0026] Multiple cooling pipes 8 are uniformly fixed inside the suction cup 1 below the electrostatic electrode 7. A second cooling medium flows inside the cooling pipe 8. Both ends of the cooling pipe 8 are connected by a connecting pipe 9. The second cooling medium is water.

[0027] Cooling pipe 8 is embedded in aluminum nitride ceramic matrix. The high thermal conductivity of aluminum nitride is used to transfer the heat generated in the electrode area to the water. The water is continuously circulated by an external pump to achieve heat exchange, which helps to maintain the stable temperature of suction cup 1 and ensures the stability of the processing.

[0028] A cylinder 4 is fixedly installed in the middle of the suction cup 1. The piston rod of the cylinder 4 moves inside the suction cup 1 and is fixed to the movable plate 3. A sealing sleeve is fixed inside the suction cup 1 and on the side near the cylinder 4, which is sleeved on the outside of the piston rod. A sealing ring 10 is fixed on the outer ring of the movable plate 3. The sealing ring 10 is slidably connected to the surface of the ventilation chamber 2.

[0029] The cylinder 4 drives the movable plate 3 to slide up and down along the ventilation cavity 2, causing the ejector pin 5 to extend or retract from the surface of the chuck 1, thus realizing the receiving and ejection of the wafer. The sealing sleeve and sealing ring 10 ensure the airtightness of the helium cavity, preventing media leakage.

[0030] The suction cup 1 is made of aluminum nitride ceramic to meet the high insulation, corrosion resistance and high thermal conductivity requirements of semiconductor processes.

[0031] Working principle: When the wafer enters the etching chamber, the ejector pin 5 rises to receive the wafer for wafer transfer. Then, the ejector pin 5 falls, placing the wafer on the surface of the electrostatic chuck. Helium gas is injected into the venting chamber 2 through the inlet pipe 11 as a cooling medium. The helium gas diffuses evenly to the bottom of the wafer through the ejector pin 5, utilizing its high thermal conductivity to remove heat from the contact surface, thus cooling the wafer. This, combined with the flow channel 6, forms a flow channel, allowing gas to flow between the bottom of the wafer and the top of the chuck 1, enhancing heat dissipation and improving the thermal stability of the electrostatic chuck.

[0032] Meanwhile, the cooling pipe 8 is embedded in the aluminum nitride ceramic matrix. The high thermal conductivity of aluminum nitride is used to transfer the heat generated in the electrode area to the water. The water is continuously circulated by an external pump to achieve heat exchange, which helps to maintain the stable temperature of the suction cup 1 and ensures the stability of the processing.

[0033] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A ceramic electrostatic chuck with uniform heat dissipation, characterized by, The utility model provides a kind of electrostatic chuck, including sucking disc (1) and multiple electrostatic electrodes (7) evenly embedded in the inside of sucking disc (1), the sucking disc (1) is made of ceramic material, the inside of the sucking disc (1) and the side close to top are hollow structure and form ventilation cavity (2), sliding plate (3) is slid on the inner wall of ventilation cavity (2), multiple thimble tubes (5) are evenly fixed in the inside of sliding plate (3), the thimble tube (5) is slid in the top side of sucking disc (1) and is hollow structure, first cooling medium flows in the inside of ventilation cavity (2). Multiple cooling pipes (8) are evenly fixed in the inside of sucking disc (1) below electrostatic electrode (7), second cooling medium flows in the inside of cooling pipe (8).

2. The uniform heat dissipating ceramic electrostatic chuck of claim 1, wherein, Multiple flow channels (6) are equipped on the top of sucking disc (1), and the flow channel (6) is communicated with thimble tube (5).

3. The uniform heat dissipating ceramic electrostatic chuck of claim 2, wherein, Air inlet pipe (11) is fixed in the inside of sucking disc (1) and communicated with ventilation cavity (2), and the first cooling medium is helium.

4. The uniform heat dissipating ceramic electrostatic chuck of claim 3, wherein, Both ends of cooling pipe (8) are fixed with communicating pipe (9) in common, and the second cooling medium is water body.

5. The uniform heat dissipating ceramic electrostatic chuck of claim 4, wherein, Air cylinder (4) is fixed in the middle of sucking disc (1), the piston rod of air cylinder (4) is movable in the inside of sucking disc (1) and fixed with sliding plate (3), and sealing sleeve is fixed on the side close to air cylinder (4) in the inside of sucking disc (1) and sleeved on the outside of piston rod.

6. The uniform heat dissipating ceramic electrostatic chuck of claim 5, wherein, Sealing ring (10) is fixed on the outer ring of sliding plate (3), and the sealing ring (10) is slidably connected with the surface of ventilation cavity (2).

7. The uniform heat dissipating ceramic electrostatic chuck of claim 6, wherein, The sucking disc (1) is made of aluminum nitride ceramic material.

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