Wafer electrostatic chuck

Abstract

The utility model relates to the technical field of electrostatic chucks, in particular to a wafer electrostatic chuck, which comprises an electrostatic chuck substrate, a bonding disc is arranged at the top of the electrostatic chuck substrate, a ceramic disc is arranged above the bonding disc, the ceramic disc is fixed above the electrostatic chuck substrate through the bonding disc, and the ceramic disc is fixed above the electrostatic chuck substrate through the bonding disc. A wafer temperature control module is arranged in the ceramic disc and the electrostatic chuck substrate, the wafer temperature control module comprises a cooling hole and a heating hole, a bearing ejector pin capable of moving up and down is arranged in the bearing hole, and the cooling hole and the heating hole are further formed in the upper portion of the ceramic disc. According to the utility model, the heating holes and the cooling holes are uniformly arranged on the ceramic insulating layer, so that the temperature of the wafer and the temperature of the insulating layer can be effectively controlled.

Description

Technical Field

[0001] The utility model relates to the technical field of electrostatic chucks, in particular to a wafer electrostatic chuck. Background Art

[0002] A wafer electrostatic chuck is a device used to fix silicon wafers during the semiconductor manufacturing process. It is widely used in processes such as PVD (physical vapor deposition), CVD (chemical vapor deposition), and ETCH (etching). The main advantage of a wafer electrostatic chuck is that it can provide a contactless fixing method, avoiding possible damage to the wafer, while also providing temperature control, which is crucial for many semiconductor processes.

[0003] Currently, a Chinese patent with publication number CN211605123U discloses an electrostatic chuck, which includes a body having a concentric central circular area, an inner annular area, and an outer annular area; the central circular area is provided with a plurality of first air holes for the passage of cooling gas; and the periphery of the inner annular area is provided with a plurality of second air holes for the passage of cooling gas.

[0004] Although this electrostatic chuck has more precise temperature control over the wafer by adding helium holes for cooling in the internal area of ​​the electrostatic chuck, the temperature cooling of the wafer surface is more uniform, and the etching uniformity is improved, however: this electrostatic chuck is only equipped with cooling holes on the surface, which can only have a cooling effect on the wafer. However, during the etching process, the wafer not only needs to be cooled, but more importantly, it needs to be maintained at a stable temperature. The cooling holes alone cannot maintain the wafer temperature in a certain equilibrium value range, which affects the stability of the process. Utility Model Content

[0005] In view of the above situation, in order to overcome the defects of the prior art, the purpose of the present invention is to provide a wafer electrostatic chuck, and the above technical objectives are achieved through the following technical solutions:

[0006] A wafer electrostatic chuck, characterized in that: it includes an electrostatic chuck substrate, an adhesive disc is provided on the top of the electrostatic chuck substrate, a ceramic disc is provided above the adhesive disc, the ceramic disc is fixed to the top of the electrostatic chuck substrate through the adhesive disc, an electrostatic electrode is provided inside the electrostatic chuck substrate, a wafer temperature control module is provided inside the ceramic disc and the electrostatic chuck substrate, the wafer temperature control module includes cooling holes and heating holes, the cooling holes and heating holes are provided above the ceramic disc, the cooling holes and heating holes are distributed in sequence along the circumference of the ceramic disc, and the upper end of the cooling hole The cooling hole is a cooling air outlet. The cavity of the cooling hole is connected from top to bottom to the lower position of the electrostatic suction cup substrate, and the lower end of the cooling hole is a cooling air inlet. The heating holes are distributed in the longitudinal direction inside the ceramic disk. The upper end of the heating hole is a heating air outlet. The lower end of the heating hole does not extend to the inside of the electrostatic suction cup substrate. A heating air inlet connected to the heating hole is provided on the side wall of the ceramic disk. A heating hole cavity extending laterally to the position of the heating air outlet is provided inside the heating air inlet. A receiving hole is also provided on the surface of the ceramic disk. A receiving pin that can move up and down is provided inside the receiving hole.

[0007] Furthermore, a heat dissipation channel is provided inside the ceramic disk. The heat dissipation channel is arranged inside the ceramic disk to enhance the heat dissipation effect and feedback the adsorption condition of the wafer. The heat dissipation channel includes an inner circle channel that diffuses outward from the center of the ceramic disk, an extended flow channel that further extends to the outer circle of the ceramic disk, and an outer circle flow channel arranged near the outer circle of the ceramic disk. The extended flow channel is used to connect the inner circle flow channel and the outer circle flow channel.

[0008] Furthermore, the extended flow channel is arranged to bypass the cavities of the cooling outlet and the heating outlet, and two groups of air inlet grooves are provided on the surface of the inner ring flow channel. A helium inlet cavity connected to the air inlet grooves is provided below the air inlet grooves.

[0009] Furthermore, a circulating water channel is provided inside the electrostatic chuck substrate, a circulating water inlet pipe is provided at one end of the circulating water channel, and a circulating water outlet pipe is provided at the other end of the circulating water channel. The circulating water inlet pipe and the circulating water outlet pipe are respectively installed on both sides of the electrostatic chuck substrate, and the circulating water inlet pipe and the circulating water outlet pipe are both embedded and fixed inside the electrostatic chuck substrate.

[0010] Furthermore, a main ejector pin module is provided at the center of the ceramic disk, and the main ejector pin module includes a sleeve, a movable ejector pin, and a connecting block. The connecting block is fixed to the inside of the electrostatic suction cup substrate, the sleeve is fixed to the upper end of the connecting block, and the movable ejector pin is assembled inside the sleeve. The side wall of the sleeve is provided with a connecting groove, and the interior of the movable ejector pin is provided with a hollow connecting cavity.

[0011] In summary, the present invention has the following beneficial effects:

[0012] The connection between the chuck and the wafer is equipped with two sets of heating holes and two sets of cooling holes. Compared with the traditional electrostatic chuck surface equipped with only cooling holes, the chuck can simultaneously pass low-temperature gas and high-temperature gas, which can maintain the temperature of the wafer within a certain range and improve the stability of the process steps.

[0013] The utility model configures a main ejector pin and four sets of auxiliary receiving ejector pins, which greatly increases the stability of the wafer during the process steps of receiving, supporting, and adsorbing the wafer. At the same time, the main ejector pin is equipped with a structural module that can be passed through helium. The direct contact between helium and the wafer effectively reduces the wafer temperature.

[0014] The utility model is equipped with a heat dissipation flow channel and a circulating water flow channel, and the dual cooling method can effectively ensure that the temperature of the electrostatic chuck and the wafer will not be too high. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application, but do not constitute an improper limitation of the present invention. In the drawings:

[0016] Figure 1 It is a top view of the utility model;

[0017] Figure 2 It is a front view of the utility model;

[0018] Figure 3 It is a side view of the utility model;

[0019] Figure 4 This utility model Figure 1 Cross-sectional view along the BB direction;

[0020] Figure 5 This utility model Figure 2 Cross-sectional view in CC direction;

[0021] Figure 6 This utility model Figure 2 Cross-sectional view in the middle DD direction;

[0022] Figure 7 It is a bottom view of the present utility model.

[0023] In the figure, 1. electrostatic suction cup substrate; 2. adhesive disc; 3. ceramic disc; 4. electrostatic electrode; 5. receiving hole; 6. receiving pin; 7. cooling outlet; 8. cooling inlet; 9. heating inlet; 10. heating outlet; 11. heat dissipation channel; 1101. inner ring channel; 1102. extension channel; 1103. outer ring channel; 12. air inlet groove; 13. helium inlet cavity; 14. circulating water inlet pipe; 15. circulating water outlet pipe; 16. circulating water channel; 17. main ejector module; 1701. sleeve; 1702. movable ejector; 1703. connecting block. DETAILED DESCRIPTION

[0024] The above and other technical contents, features and effects of the present invention are described in detail below with reference to the attached Figure 1 To the attached Figure 7 The detailed description of the embodiments will clearly show that the structural contents mentioned in the following embodiments are all based on the accompanying drawings.

[0025] Various exemplary embodiments of the present invention will be described below with reference to the accompanying drawings. Example

[0026] A wafer electrostatic chuck includes an electrostatic chuck substrate 1. An adhesive pad 2 is provided on the top of the electrostatic chuck substrate 1, which serves as a connection. A ceramic pad 3 is provided above the adhesive pad 2, which is fixed to the top of the electrostatic chuck substrate 1 through the adhesive pad 2. The electrostatic chuck substrate 1, the ceramic pad 3, and the adhesive pad 2, the connecting part between the two, together constitute the main structure of the electrostatic chuck.

[0027] An electrostatic electrode 4 is provided inside the electrostatic chuck substrate 1 . The electrostatic electrode 4 is used to generate an electric field of electrostatic force, thereby achieving the effect of adsorbing the wafer. The electrostatic electrode 4 is embedded in the insulating ceramic disk 3 .

[0028] A main ejector pin module 17 is provided at the center of the ceramic disk 3. The main ejector pin module 17 includes a sleeve 1701, a movable ejector pin 1702, and a connecting block 1703. The connecting block 1703 is fixed to the inside of the electrostatic chuck substrate 1, the sleeve 1701 is fixed to the upper end of the connecting block 1703, and the movable ejector pin 1702 is assembled inside the sleeve 1701. The side wall of the sleeve 1701 is provided with a connecting groove, and the interior of the movable ejector pin 1702 is provided with a hollow connecting cavity. Due to the hollow structure inside the main ejector pin, helium will be synchronously introduced into the lower part of the module during the operation of the main ejector pin. The helium enters the inside of the main ejector pin through the sleeve 1701, and the helium flows upward from the main ejector pin, directly contacting the wafer, which has a preliminary cooling effect on the wafer.

[0029] The surface of the ceramic disk 3 is also provided with a receiving hole 5, and the inside of the receiving hole 5 is provided with a receiving pin 6 that can move up and down. In this embodiment, the number of receiving holes 5 and corresponding receiving pins 6 is provided in four groups, and the receiving pins 6 are evenly distributed on the surface of the ceramic disk 3, and are used to assist the main pin to simultaneously lift the wafer or lower the height of the wafer.

[0030] A wafer temperature control module is provided inside the ceramic disk 3 and the electrostatic chuck substrate 1. The wafer temperature control module includes cooling holes and heating holes. Cooling holes and heating holes are also provided above the ceramic disk 3. The cooling holes and heating holes are arranged in sequence along the ceramic disk 3. The upper end of the cooling hole is a cooling air outlet 7. The cavity of the cooling hole is connected from top to bottom to the lower position of the electrostatic chuck substrate 1, and the lower end of the cooling hole is a cooling air inlet 8. The heating holes are distributed inside the ceramic disk 3 in a longitudinal direction. The upper end of the heating hole is a heating air outlet 10. The lower end of the heating hole does not extend into the electrostatic chuck substrate 1. A heating air inlet 9 connected to the heating hole is provided on the side wall of the ceramic disk 3. A heating hole cavity extending laterally to the position of the heating air outlet 10 is provided inside the heating air inlet 9. In this embodiment, two groups of heating holes and two groups of cooling holes are provided. The heating hole is used to pass high-temperature gas, and the cooling hole is used to pass low-temperature gas. When the two work at the same time, the problem of the wafer can be maintained in a relatively stable numerical range, thereby improving the stability of the process.

[0031] A heat dissipation channel 11 is provided inside the ceramic disk 3. The heat dissipation channel 11 is arranged inside the ceramic disk 3 to enhance the heat dissipation effect and feedback the adsorption condition of the wafer. The heat dissipation channel 11 includes an inner circle channel 1101 that diffuses outward from the center of the ceramic disk 3, an extended channel 1102 that further extends to the outer circle of the ceramic disk 3, and an outer circle channel 1103 that is arranged near the outer circle of the ceramic disk 3. The extended channel 1102 is used to connect the inner circle channel 1101 and the outer circle channel 1103. Helium also needs to be introduced into the heat dissipation channel 11. The helium here does not directly contact the wafer, but flows inside the ceramic disk 3. Its flow channel design can make the helium in the heat dissipation channel 11 evenly distributed to various positions of the ceramic disk 3, so as to maintain the stability and balance of the temperature of the ceramic disk 3 and each position of the wafer as much as possible.

[0032] The extended flow channel 1102 is arranged to bypass the cavities of the cooling outlet 7 and the heating outlet 10. Two groups of air inlet grooves 12 are provided on the surface of the inner ring flow channel 1101. A helium inlet cavity 13 connected to the air inlet groove 12 is provided below the air inlet groove 12.

[0033] A circulating water channel 16 is provided inside the electrostatic chuck substrate 1, and a circulating water inlet pipe 14 is provided at one end of the circulating water channel 16, and a circulating water outlet pipe 15 is provided at the other end of the circulating water channel 16. The circulating water inlet pipe 14 and the circulating water outlet pipe 15 are respectively installed on both sides of the inside of the electrostatic chuck substrate 1, and the circulating water inlet pipe 14 and the circulating water outlet pipe 15 are both embedded and fixed inside the electrostatic chuck substrate 1. The setting of the circulating water channel 16 is to effectively control the overall temperature of the electrostatic chuck.

[0034] The above is a further detailed description of the present invention in combination with a specific implementation method, and it cannot be determined that the specific implementation of the present invention is limited to this. For technical personnel in the field of the present invention and related technical fields, based on the technical solution of the present invention, any expansion and replacement of operating methods and data should fall within the scope of protection of the present invention.

Claims

1. A wafer electrostatic chuck, characterized by: The invention comprises an electrostatic chuck substrate (1), wherein an adhesive disc (2) is provided on the top of the electrostatic chuck substrate (1), a ceramic disc (3) is provided above the adhesive disc (2), and the ceramic disc (3) is fixed to the top of the electrostatic chuck substrate (1) through the adhesive disc (2), an electrostatic electrode (4) is provided inside the electrostatic chuck substrate (1), and a wafer temperature control module is provided inside the ceramic disc (3) and the electrostatic chuck substrate (1), and the wafer temperature control module comprises a cooling hole and a heating hole, wherein the cooling hole and the heating hole are provided above the ceramic disc (3), and the cooling hole and the heating hole are arranged and distributed in sequence along a circle of the ceramic disc (3), and the upper end of the cooling hole is a cooling air outlet (7). The cavity of the cooling hole is connected from top to bottom to the lower position of the electrostatic suction cup substrate (1), and the lower end of the cooling hole is a cooling air inlet (8). The heating hole is distributed in the longitudinal direction inside the ceramic disk (3). The upper end of the heating hole is a heating air outlet (10). The lower end of the heating hole does not extend to the inside of the electrostatic suction cup substrate (1). The side wall of the ceramic disk (3) is provided with a heating air inlet (9) connected to the heating hole. The interior of the heating air inlet (9) is provided with a heating hole cavity extending laterally to the position of the heating air outlet (10). The surface of the ceramic disk (3) is also provided with a receiving hole (5), and the interior of the receiving hole (5) is provided with a receiving pin (6) that can move up and down.

2. The wafer electrostatic chuck according to claim 1, wherein: A heat dissipation channel (11) is provided inside the ceramic disk (3). The heat dissipation channel (11) is arranged inside the ceramic disk (3) for enhancing the heat dissipation effect and providing feedback on the adsorption condition of the wafer. The heat dissipation channel (111) includes an inner ring channel (1101) that diffuses outward from the center of the ceramic disk (3), an extended channel (1102) that further extends toward the outer ring of the ceramic disk (3), and an outer ring channel (1103) that is arranged near the outer ring of the ceramic disk (3). The extended channel (1102) is used to connect the inner ring channel (1101) and the outer ring channel (1103).

3. The wafer electrostatic chuck according to claim 2, wherein: The extended flow channel (1102) is arranged to bypass the cavities of the cooling air outlet (7) and the heating air outlet (10), and two groups of air inlet grooves (12) are provided on the surface of the inner ring flow channel (1101), and a helium inlet cavity (13) connected to the air inlet groove (12) is provided below the air inlet groove (12).

4. The wafer electrostatic chuck according to claim 1, wherein: A circulating water channel (16) is provided inside the electrostatic chuck substrate (1), a circulating water inlet pipe (14) is provided at one end of the circulating water channel (16), and a circulating water outlet pipe (15) is provided at the other end of the circulating water channel (16), the circulating water inlet pipe (14) and the circulating water outlet pipe (15) are respectively installed on both sides of the inside of the electrostatic chuck substrate (1), and the circulating water inlet pipe (14) and the circulating water outlet pipe (15) are both embedded and fixed inside the electrostatic chuck substrate (1).

5. The wafer electrostatic chuck according to claim 1, wherein: A main ejector pin module (17) is provided at the center of the ceramic disk (3), and the main ejector pin module (17) includes a sleeve (1701), a movable ejector pin (1702), and a connecting block (1703). The connecting block (1703) is fixed to the inside of the electrostatic suction cup substrate (1), the sleeve (1701) is fixed to the upper end of the connecting block (1703), the movable ejector pin (1702) is assembled inside the sleeve (1701), the side wall of the sleeve (1701) is provided with a connecting groove, and the inside of the movable ejector pin (1702) is provided with a hollow connecting cavity.

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