Electrostatic chuck and manufacturing method

Abstract

The invention discloses an electrostatic chuck and a manufacturing method, and the electrostatic chuck comprises a base layer which is made of a metal material and is used for providing a stable supporting structure to ensure the stability; the dielectric adsorption layer is used for achieving insulation and heat conduction effects; the electrode layer is used for generating an electric field of electrostatic force; the bonding layer is used for realizing bonding and fixing between the two; and the helium flow channels are used for realizing circulation of helium on the surface of the dielectric adsorption layer and realizing conversion of helium from a laminar flow state to a turbulent flow state. Under the cooperation of the cylindrical flow channel, the first circular truncated cone flow channel and the second circular truncated cone flow channel, the volume of helium in the flow channel is rapidly increased, the flow speed is increased, the Reynolds number is increased, due to the fact that the second circular truncated cone flow channel has the smaller taper, the flow speed of the helium can be further rapidly increased, a turbulent flow state is formed, the complexity of helium fluid movement is increased, and the reliability of helium fluid movement is improved. Therefore, the temperature of the fluid in the whole flow channel is increased, and the temperature gradient is relatively reduced, thereby improving the uniformity and efficiency of heat dissipation of the wafer.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to an electrostatic chuck and a manufacturing method thereof. Background Art

[0002] In the field of semiconductor manufacturing, electrostatic chucks (ESC) widely replace mechanical chucks and use electrostatic attraction to adsorb the workpiece. During wafer processing, the principle of electrostatic adsorption is used to clamp ultra-thin wafers evenly and evenly. In addition, it also plays a role in heat dissipation, using the heat conduction system of the electrostatic chuck and the helium gas to conduct away the heat generated during the processing. It is widely used in high-end semiconductor manufacturing equipment such as PVD, PECVD, ETCH, EUVL, and ion implantation.

[0003] However, the electrostatic chuck in the prior art has a significant drawback in the helium flow channel design used in the wafer preparation process, especially in terms of heat dissipation control. The purged helium fluid is often in a laminar state, and the fluid molecules in the laminar state move in a relatively orderly manner, with almost no heat exchange or mixing between layers. Therefore, when helium passes through the flow channel in a laminar state, its heat transfer efficiency is relatively low, and it is unable to quickly take away the heat generated by the wafer, resulting in excessively high local temperatures on the wafer, affecting processing accuracy and product quality.

[0004] Therefore, it is necessary to improve the deficiencies in the prior art to solve the above problems. Summary of the invention

[0005] The present invention overcomes the deficiencies of the prior art and provides an electrostatic chuck and a manufacturing method thereof.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: an electrostatic chuck, comprising:

[0007] The base layer of metal material is used to provide a stable supporting structure to ensure stability;

[0008] A dielectric adsorption layer, which is formed on the top of the base layer and is used for insulation and heat conduction;

[0009] An electrode layer, wherein the electrode layer is embedded in the dielectric adsorption layer and is used to generate an electric field of electrostatic force;

[0010] An adhesive layer, the adhesive layer is located between the base layer and the dielectric adsorption layer, and is used to achieve bonding and fixing between the two;

[0011] A plurality of helium flow channels are provided, which extend from the bottom of the base layer upward through the bonding layer and the dielectric adsorption layer in sequence, so as to realize the circulation of helium on the surface of the dielectric adsorption layer and realize the transition of helium from a laminar flow state to a turbulent flow state.

[0012] In a preferred embodiment of the present invention, the helium flow channel includes, from bottom to top, a cylindrical flow channel, a first truncated cone flow channel and a second truncated cone flow channel; the first truncated cone flow channel and the second truncated cone flow channel are located in the dielectric adsorption layer and above the electrode layer; the diameter of the cylindrical flow channel is 0.5 to 1.5 mm, the taper of the first truncated cone flow channel is 1:1.5 to 3, and the taper of the second truncated cone flow channel is 1:2.5 to 4.5.

[0013] In a preferred embodiment of the present invention, the diameter of the bottom edge of the first conical flow channel is the same as the diameter of the cylindrical flow channel, the top of the first conical flow channel and the bottom of the second conical flow channel form a stepped structure, and the cylindrical flow channel, the first conical flow channel and the second conical flow channel are coaxially arranged.

[0014] In a preferred embodiment of the present invention, a DC positive line and a DC negative line are connected to the electrode layer, and the bottom ends of the DC positive line and the DC negative line pass through the dielectric adsorption layer, the adhesive layer and the base layer in sequence.

[0015] In a preferred embodiment of the present invention, a heater for providing a heat source to avoid temperature fluctuations of the workpiece is embedded inside the adhesive layer, a heating power line is connected to the heater, and the bottom end of the heating power line passes downward through the adhesive layer and the base layer in sequence.

[0016] In a preferred embodiment of the present invention, a plurality of coolant flow channels are opened inside the base layer, a coolant inlet and a coolant outlet are opened at the bottom of the base layer, and the coolant inlet and the coolant outlet are respectively connected to the interiors of the plurality of coolant flow channels.

[0017] In a preferred embodiment of the present invention, the dielectric adsorption layer is made of aluminum nitride or aluminum oxide ceramic.

[0018] In a preferred embodiment of the present invention, the electrode layer is formed by vacuum coating technology, and the material is one of aluminum, copper or tungsten.

[0019] In a preferred embodiment of the present invention, the bonding layer is formed by curing an organic adhesive, and the organic adhesive is one of epoxy resin, polyurethane resin, acrylic resin or silicone resin.

[0020] The present invention provides a method for manufacturing an electrostatic chuck, comprising the following steps:

[0021] S1. providing a base layer of metal material;

[0022] S2, forming a dielectric adsorption layer and an electrode layer, wherein the electrode layer is embedded in the dielectric adsorption layer;

[0023] S3, forming an adhesive layer between the base layer and the dielectric adsorption layer, so that the dielectric adsorption layer is connected to the upper surface of the base layer;

[0024] S4. Using material removal technology, a number of helium flow channels are formed from the bottom of the base layer to the top of the dielectric adsorption layer to obtain an electrostatic chuck.

[0025] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0026] (1) The present invention provides an electrostatic suction cup and a manufacturing method. By setting up a plurality of helium flow channels, when helium is introduced to provide a heat dissipation effect, through the cooperation of the cylindrical flow channel, the first truncated cone flow channel and the second truncated cone flow channel, when the helium enters the first truncated cone flow channel from the cylindrical flow channel, due to the change in the taper of the first truncated cone flow channel, the volume of the helium in the flow channel increases rapidly, resulting in an accelerated flow rate and an increased Reynolds number. When the helium continues to enter the second truncated cone flow channel through the stepped structure between the first truncated cone flow channel and the second truncated cone flow channel, since the second truncated cone flow channel has a smaller taper, the flow rate of the helium will further increase sharply, forming a turbulent state, increasing the complexity of the helium fluid movement, causing the temperature of the entire flow channel fluid to increase, and the temperature gradient to relatively decrease, thereby improving the uniformity and efficiency of heat dissipation of the wafer.

[0027] (2) In the present invention, the stepped structure of the transition section between the first conical flow channel and the second conical flow channel, due to the sudden narrowing of the cross-section, will cause the helium to generate a lower pressure. This pressure gradient promotes the flow of helium into the second conical flow channel, making it easier for the helium to pass through the interior. The smaller taper of the second conical flow channel relative to the first conical flow channel helps to maintain the contact between the helium fluid and the wafer surface, while making its Reynolds number exceed the critical value, effectively forming a turbulent state, thereby improving the efficiency of heat exchange.

[0028] (3) In the present invention, the turbulent state increases the contact area between the helium and the wafer surface and prolongs the residence time of the helium on the wafer surface. The changes in flow rate and state enable the helium to more effectively penetrate the tiny gap between the wafer and the suction cup, thereby further promoting heat exchange and enhancing the heat transfer effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 is a schematic structural diagram of an electrostatic chuck according to a preferred embodiment of the present invention;

[0031] Figure 2 It is a preferred embodiment of the present invention Figure 1 The enlarged structural diagram at A in the middle;

[0032] Figure 3 is a flow chart of a method for manufacturing an electrostatic chuck according to a preferred embodiment of the present invention;

[0033] In the figure: 1. base layer; 2. dielectric adsorption layer; 3. electrode layer; 31. DC positive line; 32. DC negative line; 4. bonding layer; 5. helium flow channel; 51. cylindrical flow channel; 52. first truncated cone flow channel; 53. second truncated cone flow channel; 6. heater; 61. heating power line; 7. coolant flow channel; 71. coolant inlet; 72. coolant outlet. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0036] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention, unless otherwise specified, "multiple" means two or more.

[0037] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood by specific circumstances.

[0038] like Figure 1 As shown, an electrostatic chuck comprises:

[0039] A base layer 1 of metal material is used to provide a stable supporting structure to ensure stability;

[0040] The dielectric adsorption layer 2 is formed on the top of the base layer 1 to provide insulation and heat conduction effects;

[0041] The electrode layer 3 is embedded in the dielectric adsorption layer 2 and is used to generate an electric field of electrostatic force;

[0042] The bonding layer 4 is located between the base layer 1 and the dielectric adsorption layer 2 to achieve bonding and fixing between the two;

[0043] A plurality of helium flow channels 5 are provided, which extend from the bottom of the base layer 1 upward through the adhesive layer 4 and the dielectric adsorption layer 2 in sequence, so as to realize the circulation of helium on the surface of the dielectric adsorption layer 2 and realize the transition of the helium from a laminar flow state to a turbulent flow state.

[0044] It should be noted that the tops of several helium flow channels 5 are evenly distributed on the surface of the dielectric adsorption layer 2 in a circumferential direction, and diffuse from the middle to the outside in a gradually increasing number. The helium flow channel 5 is connected to a cooling gas supply source, which can supply cooling gas to the helium flow channel 5. The cooling gas can be an inert gas, and the preferred cooling gas is helium. In a vacuum environment or a plasma environment, when the wafer is implemented as a carrier, the surface of the dielectric adsorption layer 2 contacts the wafer. When the electrode layer 3 is connected to a DC power supply, polarized charges will be generated on the surface of the dielectric adsorption layer 2 and an electric field will be formed, which will further generate polarized charges of opposite polarity on the surface of the wafer placed on the dielectric adsorption layer 2, and then the two heterogeneous charges will attract each other, so that the wafer is adsorbed on the electrostatic suction cup, and the helium flowing through the helium flow channel 5 can easily pass through tiny channels and gaps, thereby enhancing the heat dissipation of the wafer and helping to maintain good contact between the wafer and the suction cup.

[0045] like Figure 2 As shown, in some embodiments, the helium flow channel 5 includes, from bottom to top, a cylindrical flow channel 51, a first truncated cone flow channel 52, and a second truncated cone flow channel 53; the first truncated cone flow channel 52 and the second truncated cone flow channel 53 are located in the dielectric adsorption layer 2 and above the electrode layer 3; the diameter of the cylindrical flow channel 51 is 0.5 to 1.5 mm, the taper of the first truncated cone flow channel 52 is 1:1.5 to 3, and the taper of the second truncated cone flow channel 53 is 1:2.5 to 4.5.

[0046] It should be noted that the diameter of the bottom edge of the first truncated cone flow channel 52 is the same as the diameter of the cylindrical flow channel 51, and a stepped structure is formed at the top of the first truncated cone flow channel 52 and the bottom of the second truncated cone flow channel 53. The cylindrical flow channel 51, the first truncated cone flow channel 52 and the second truncated cone flow channel 53 are coaxially arranged; helium enters from the cylindrical flow channel 51, and when the helium enters the first truncated cone flow channel 52 from the cylindrical flow channel 51, the first truncated cone flow channel 52 changes in a certain taper, and the helium fluid increases rapidly when passing through the first truncated cone flow channel 52, resulting in an increase in the Reynolds number, and when the helium is in the stepped structure of the transition section between the first truncated cone flow channel 52 and the second truncated cone flow channel 53, since the second truncated cone flow channel 53 has a smaller taper, its cross-section suddenly becomes narrower, and the flow velocity increases sharply, forming a The pressure of the gas is lowered, which promotes the flow of helium into the second conical flow channel 53, thereby causing the Reynolds number to further increase and exceed the critical value, and can change the flow state of the helium from a laminar state to a turbulent state, thereby increasing the complexity of the movement of the helium fluid, increasing the temperature of the entire flow channel fluid, and relatively reducing the temperature gradient, thereby improving the uniformity and efficiency of the heat dissipation of the wafer. The larger taper of the first conical flow channel 52 relative to the second conical flow channel 53 helps to reduce the resistance to fluid flow and makes it easier for helium to pass through it. The smaller taper of the second conical flow channel 53 relative to the first conical flow channel 52 helps to maintain the contact between the helium fluid and the wafer surface, thereby further promoting heat exchange and enhancing the heat transfer effect.

[0047] like Figure 1 As shown, in some embodiments, the electrode layer 3 is connected to a DC positive line 31 and a DC negative line 32, and the bottom ends of the DC positive line 31 and the DC negative line 32 penetrate downwardly through the dielectric adsorption layer 2, the bonding layer 4 and the base layer 1 in sequence.

[0048] It should be noted that the DC positive line 31 and the DC negative line 32 are formed to be embedded in the dielectric adsorption layer 2, the adhesive layer 4 and the base layer 1. In the process of forming the electrode layer 3, the DC positive line 31 and the DC negative line 32 can be formed on the electrode layer 3, and the DC positive line 31 and the DC negative line 32 are connected to the DC power supply equipment, and the DC power flows into the electrode layer 3 through the DC positive line 31 and then flows out through the DC negative line 32, so that an electric field is formed between the electrode layers 3, thereby realizing electrostatic adsorption.

[0049] In some embodiments, a heater 6 for providing a heat source to prevent temperature fluctuations of the workpiece is embedded inside the adhesive layer 4. A heating power line 61 is connected to the heater 6. The bottom end of the heating power line 61 passes through the adhesive layer 4 and the base layer 1 in sequence.

[0050] It should be noted that the heating power line 61 is formed to be embedded in the adhesive layer 4 and the base layer 1, and the heating power line 61 is connected to the power supply device; the heater 6 generates heat by providing current through the heating power line 61, which is directly transferred to the dielectric adsorption layer 2 and the workpiece, such as a wafer, to achieve rapid heating or local heating processing; for example, it can be used to control the temperature of the wafer to prevent the wafer from being affected by temperature fluctuations, causing thermal stress or thermal deformation due to excessive temperature gradients.

[0051] In some embodiments, a plurality of coolant channels 7 are opened inside the base layer 1 , a coolant inlet 71 and a coolant outlet 72 are opened at the bottom of the base layer 1 , and the coolant inlet 71 and the coolant outlet 72 are respectively connected to the interior of the plurality of coolant channels 7 .

[0052] It should be noted that the coolant inlet 71 and the coolant outlet 72 are located at the edge of the base layer 1 and are connected to an external cooling system for circulating and providing coolant. The cooling system allows the coolant to enter the coolant channel 7 through the coolant inlet 71. After the coolant flows in the coolant channel 7 and absorbs the heat of the electrostatic chuck and the wafer, it is discharged from the coolant channel 7 through the coolant outlet 72 and sent back to the cooling system for cooling. This cycle is repeated to keep the temperature of the electrostatic chuck and the wafer stable during the processing.

[0053] like Figure 3 As shown, the present invention provides a method for manufacturing an electrostatic chuck, comprising the following steps:

[0054] S1, providing a base layer 1 of a metal material;

[0055] It should be noted that the base layer 1 is generally made of metal such as aluminum, titanium alloy, or stainless steel, which is conducive to the input of radio frequency energy. It can also be made of a composite of ceramics and metals that provides good strength and durability as well as heat transfer. The base layer 1 can be constructed with various changes in materials and structures according to the usage conditions. Its manufacturing method can be formed by existing technologies and will not be described in detail here.

[0056] S2, forming a dielectric adsorption layer 2 and an electrode layer 3, wherein the electrode layer 3 is embedded in the dielectric adsorption layer 2;

[0057] It should be noted that the material of the dielectric adsorption layer 2 is aluminum nitride or aluminum oxide ceramic, which is formed by a sintering process. The material of the electrode layer 3 is one of aluminum, copper or tungsten; the electrode layer 3 is formed by vacuum coating technology, such as chemical vapor deposition or physical vapor deposition, to obtain higher component purity, tissue density and resistivity; it can also be formed by other existing technologies such as screen printing. The formation process of the dielectric adsorption layer 2 and the electrode layer 3 is well known to those skilled in the art, and the specific details are not described in detail here.

[0058] S3, forming an adhesive layer 4 between the base layer 1 and the dielectric adsorption layer 2, so that the dielectric adsorption layer 2 is connected to the upper surface of the base layer 1;

[0059] It should be noted that the adhesive layer 4 can be provided with one or more layers, and is formed by curing one or more organic adhesives, and the organic adhesive is one of epoxy resin, polyurethane resin, acrylic resin or silicone resin.

[0060] S4. Using material removal technology, a plurality of helium flow channels 5 are formed from the bottom of the base layer 1 to the top of the dielectric adsorption layer 2 to obtain an electrostatic chuck.

[0061] It should be noted that at least one helium flow channel 5 can be formed using any known or yet to be developed material removal technology; non-limiting examples of material removal technology include grinding, laser cutting, etching, machining, photolithography, hybrid laser / water, etching and sandblasting or gravel blasting, etc.

[0062] The following is a detailed description of the overall implementation of the present invention in conjunction with specific examples.

[0063] Example 1

[0064] A method for manufacturing an electrostatic chuck comprises the following steps:

[0065] S1, providing a base layer 1 of aluminum metal material;

[0066] S2, forming a dielectric adsorption layer 2 made of alumina ceramic by a sintering process, and forming an electrode layer 3 made of tungsten by chemical vapor deposition, wherein the electrode layer 3 is embedded in the dielectric adsorption layer 2;

[0067] S3, forming an adhesive layer 4 made of silicone resin between the base layer 1 and the dielectric adsorption layer 2, so that the dielectric adsorption layer 2 is connected to the upper surface of the base layer 1;

[0068] S4. By means of mechanical processing, a cylindrical flow channel 51 with a diameter of 1 mm is formed from the bottom of the base layer 1 to the top of the dielectric adsorption layer 2; a first truncated cone flow channel 52 with a bottom diameter of 1 mm, a top diameter of 0.6 mm, and a height of 0.8 mm; and a second truncated cone flow channel 53 with a bottom diameter of 0.4 mm, a top diameter of 0.2 mm, and a height of 0.8 mm are formed; and an electrostatic suction cup is obtained.

[0069] Comparative Example 1

[0070] This comparative example is basically the same as Example 1, except that: Step S4 is: using mechanical processing to form a cylindrical flow channel 51 with a diameter of 1 mm from the bottom of the base layer 1 to the top of the dielectric adsorption layer 2; and obtaining an electrostatic chuck.

[0071] Comparative Example 2

[0072] This comparative example is basically the same as Example 1, except that: Step S4 is: using mechanical processing to form a cylindrical flow channel 51 with a diameter of 1 mm from the bottom of the base layer 1 to the top of the dielectric adsorption layer 2; a first truncated cone flow channel 52 with a bottom diameter of 1 mm, a top diameter of 0.6 mm, and a height of 0.8 mm; and an electrostatic suction cup is obtained.

[0073] Comparative Example 3

[0074] This comparative example is basically the same as Example 1, except that: Step S4 is: using mechanical processing to form a cylindrical flow channel 51 with a diameter of 1 mm from the bottom of the base layer 1 to the top of the dielectric adsorption layer 2; a first truncated cone flow channel 52 with a bottom diameter of 1 mm, a top diameter of 0.6 mm, and a height of 0.8 mm; a second truncated cone flow channel 53 with a bottom diameter of 0.4 mm, a top diameter of 0.2.5 mm, and a height of 0.8 mm; and an electrostatic suction cup is obtained.

[0075] Performance test: fix the electrostatic chuck prepared in Example 1 and Comparative Examples 1-3, place the wafer on the electrostatic chuck, set the wafer surface temperature to 80°C, pass the helium flow channel 5 at a helium flow rate of 500 SCCM, purge for 10 seconds, use a high-precision infrared thermal imager to record the temperature data of the wafer surface after purging, repeat the test 3 times, and take the average value. The performance test results are shown in Table 1.

[0076] Table 1:

[0077] Performance Testing Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Helium flow rate (SCCM) 500 500 500 500 Initial temperature(℃) 80 80 80 80 Purge time(s) 10 10 10 10 Average temperature after measurement (℃) 20.5 42.7 38.4 32.2

[0078] It can be seen from Table 1 that:

[0079] By comparing Example 1 with Comparative Example 1, it can be seen that the first conical flow channel 52 and the second conical flow channel 53 with a certain taper are used to promote the transformation of helium from a laminar state to a turbulent state by utilizing the change in their taper, which significantly improves the heat exchange efficiency between the helium and the wafer, thereby achieving a better heat dissipation effect.

[0080] By comparing Example 1 with Comparative Example 2, it can be learned that by providing a second conical flow channel 53 with a certain taper on the basis of the first conical flow channel 52, the transition section of the stepped structure, due to the sudden narrowing of the cross-section, the helium will produce a lower pressure. This pressure gradient promotes the flow of helium into the second conical flow channel 53, so that its Reynolds number exceeds the critical value, effectively forming a turbulent state, and the changes in flow rate and state enable the helium to more effectively penetrate the tiny gap between the wafer and the suction cup, thereby improving the efficiency of heat exchange.

[0081] By comparing Example 1 with Comparative Example 3, it can be learned that although Comparative Example 3 introduces the structural design of the second truncated cone flow channel 53 on the basis of the first truncated cone flow channel 52, since the taper of the second truncated cone flow channel 53 is too small, the flow velocity of helium when passing through the flow channel is not increased significantly enough, and the pressure gradient does not change drastically enough, which in turn affects the generation of the turbulent state and thus affects the heat dissipation effect of the wafer.

[0082] The above is based on the ideal embodiment of the present invention. Through the above description, it is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0083] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An electrostatic chuck, characterized in that: include: The base layer of metal material is used to provide a stable supporting structure to ensure stability; A dielectric adsorption layer, which is formed on the top of the base layer and is used for insulation and heat conduction; An electrode layer, wherein the electrode layer is embedded in the dielectric adsorption layer and is used to generate an electric field of electrostatic force; An adhesive layer, the adhesive layer is located between the base layer and the dielectric adsorption layer, and is used to achieve bonding and fixing between the two; A plurality of helium flow channels are provided, which extend from the bottom of the base layer upward through the bonding layer and the dielectric adsorption layer in sequence, so as to realize the circulation of helium on the surface of the dielectric adsorption layer and realize the transition of helium from a laminar flow state to a turbulent flow state.

2. An electrostatic chuck according to claim 1, characterized in that: The helium flow channel includes, from bottom to top, a cylindrical flow channel, a first truncated cone flow channel and a second truncated cone flow channel; the first truncated cone flow channel and the second truncated cone flow channel are located in the dielectric adsorption layer and above the electrode layer; the diameter of the cylindrical flow channel is 0.5 to 1.5 mm, the taper of the first truncated cone flow channel is 1:1.5 to 3, and the taper of the second truncated cone flow channel is 1:2.5 to 4.

5.

3. An electrostatic chuck according to claim 2, characterized in that: The diameter of the bottom edge of the first truncated cone flow channel is the same as the diameter of the cylindrical flow channel, the top of the first truncated cone flow channel and the bottom of the second truncated cone flow channel form a stepped structure, and the cylindrical flow channel, the first truncated cone flow channel and the second truncated cone flow channel are coaxially arranged.

4. An electrostatic chuck according to claim 1, characterized in that: The electrode layer is connected with a DC positive line and a DC negative line, and the bottom ends of the DC positive line and the DC negative line sequentially penetrate downwardly through the dielectric adsorption layer, the bonding layer and the base layer.

5. The electrostatic chuck according to claim 1, characterized in that: A heater for providing a heat source to prevent the workpiece temperature from fluctuating is embedded in the inner side of the adhesive layer. A heating power line is connected to the heater, and the bottom end of the heating power line passes through the adhesive layer and the base layer in sequence.

6. An electrostatic chuck according to claim 1, characterized in that: A plurality of cooling liquid flow channels are provided inside the base layer, and a cooling liquid inlet and a cooling liquid outlet are provided at the bottom of the base layer. The cooling liquid inlet and the cooling liquid outlet are respectively connected to the interiors of the plurality of cooling liquid flow channels.

7. An electrostatic chuck according to claim 1, characterized in that: The dielectric adsorption layer is made of aluminum nitride or aluminum oxide ceramic.

8. An electrostatic chuck according to claim 1, characterized in that: The electrode layer is formed by vacuum coating technology, and the material is one of aluminum, copper or tungsten.

9. An electrostatic chuck according to claim 1, characterized in that: The bonding layer is formed by curing an organic adhesive, and the organic adhesive is one of epoxy resin, polyurethane resin, acrylic resin or silicone resin.

10. A method for manufacturing an electrostatic chuck according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. providing a base layer of metal material; S2, forming a dielectric adsorption layer and an electrode layer, wherein the electrode layer is embedded in the dielectric adsorption layer; S3, forming an adhesive layer between the base layer and the dielectric adsorption layer, so that the dielectric adsorption layer is connected to the upper surface of the base layer; S4. Using material removal technology, a number of helium flow channels are formed from the bottom of the base layer to the top of the dielectric adsorption layer to obtain an electrostatic chuck.

Images