Semiconductor electrostatic chuck and method of manufacture

Abstract

The application relates to the technical field of semiconductors, and discloses a semiconductor electrostatic chuck and a preparation method, which comprise a base, the top surface of the base is provided with a mounting hole, the top surface of the base is fixedly provided with an adsorption layer, and the surface of the adsorption layer is provided with an outer ring cooling air groove, an outer ring cooling air channel, an inner ring cooling air groove and an inner ring cooling air channel. The electrode group A contact and the electrode group B contact are electrified with the equipment, then the electrode group A and the electrode group B are both in a charged state, the electrode group A and the electrode group B are both away from the surface of the adsorption layer by a distance, an electrostatic field can be formed on the surface of the adsorption layer, the effect of adsorbing wafers is achieved, the electrode group A contact and the electrode group B contact are electrically connected with the electrode group A and the electrode group B respectively, the adsorption layer can be directly replaced as a whole by dismounting, the electrode group A contact and the electrode group B contact are not damaged during the replacement process, the maintenance period is shortened, and the application cost of the electrostatic chuck is reduced.

Description

TECHNICAL FIELD

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

[0002] At present, in the domestic semiconductor manufacturing process, especially in the process of ion, etching, film, etc. of wafer, in order to avoid the wafer from deviating in the process and the wafer from being warped and falling off due to temperature rise in the process, the wafer needs to be temperature controlled in the process to provide heat dissipation function. In these high vacuum, plasma, halogen environments, the electrostatic chuck is often used to effectively clamp the wafer. The current electrostatic chuck often has low adsorption force and uneven adsorption force in actual application. When the chuck head is replaced, the circuit control part needs to be replaced as a whole, the maintenance cycle is long, and the replacement efficiency is slow. SUMMARY

[0003] The present application relates to the technical field of semiconductor, in particular to a semiconductor electrostatic chuck and a preparation method thereof.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme: a semiconductor electrostatic chuck and a preparation method thereof, comprising a base, a mounting hole is formed on the top surface of the base, an adsorption layer is fixedly installed on the top surface of the base, an outer ring cooling gas groove, an outer ring cooling gas channel, an inner ring cooling gas groove and an inner ring cooling gas channel are formed on the surface of the adsorption layer, the outer ring cooling gas groove is connected with the outer ring cooling gas channel in communication, the inner ring cooling gas groove is connected with the inner ring cooling gas channel in communication, the outer ring cooling gas channel is located outside the inner ring cooling gas channel, a jacking column hole is formed on the surface of the adsorption layer, an electrode group is fixedly installed inside the adsorption layer, an electrode group A and an electrode group B are fixedly installed inside the electrode group, an electrode group A contact and an electrode group B contact are fixedly installed on the bottom surface of the adsorption layer, the electrode group A contact is in electrical contact with the electrode group A, the electrode group B contact is in electrical contact with the electrode group B, and a positioning pin hole is formed on the bottom surface of the base.

[0005] As a preferred embodiment of the present application, the electrode group A and the electrode group B are both annular, the electrode group B is located inside the electrode group A, and the spacing between the electrode group A and the electrode group B is 80 mu m.

[0006] As a preferred embodiment of the present application, an insulating adhesive is filled between the electrode group A and the electrode group B, and the thickness of the insulating adhesive is 90 mu m.

[0007] As a preferred embodiment of the present application, concave surfaces are formed on the top surfaces of the inner ring cooling gas groove and the outer ring cooling gas groove, and round corners are formed on the end surfaces of the inner ring cooling gas groove and the outer ring cooling gas groove.

[0008] As a preferred embodiment of the present application, the adsorption layer is provided with a cooling gas inlet in the middle part, the cooling gas inlet is connected with the inner ring cooling gas channel and the outer ring cooling gas channel respectively, and the input end of the cooling gas inlet is located in the middle part of the base.

[0009] As a preferred embodiment of the present application, an electrostatic chuck is provided, which comprises a base and an adsorption layer arranged on the base; wherein the base is made of aluminum alloy material, and the surface thereof is treated by hard sulfuric acid anode or ceramic thermal spraying; wherein the adsorption layer is made of polyimide, polytetrafluoroethylene, polyurethane, silicone rubber or other insulating materials, and a plurality of electrode groups which are crosswise arranged are arranged in the adsorption layer, and the electrode groups are made of one or more conductive materials such as copper foil, silver foil and gold foil.

[0010] As a preferred embodiment of the present application, the electrode groups comprise electrode group A contact points and electrode group B contact points, the electrode group A contact points and the electrode group B contact points penetrate through the base, the upper ends of the electrode group A contact points and the electrode group B contact points are respectively in contact with the electrode group A and the electrode group B, the lower ends of the electrode group A contact points and the electrode group B contact points are fixed on the base, and the electrode group A contact points and the electrode group B contact points are made of polyimide, polytetrafluoroethylene, polyurethane, silicone rubber or other insulating materials.

[0011] As a preferred embodiment of the present application, the adsorption layer is provided with two groups of inner ring cooling gas channels and outer ring cooling gas channels which are in communication and arranged in a ring shape, the inner ring cooling gas channels and the outer ring cooling gas channels are equally divided, each region acts on the same position of the wafer, the cross sections of the inner ring cooling gas channels and the outer ring cooling gas channels are in a rectangular state when the wafer is in a process stage, the surfaces are concave and can store a certain amount of cooling gas, and the cooling gas can provide more contact area with the wafer, and the upper edges of the cross sections of the inner ring cooling gas channels and the outer ring cooling gas channels are transitioned by round corners.

[0012] As a preferred embodiment of the present application, the surfaces of the inner ring cooling gas channels and the outer ring cooling gas channels are treated by hard sulfuric acid anode or ceramic thermal spraying on the basis of the rectangular state of the cross sections.

[0013] Compared with the prior art, the present application has the following advantages:

[0014] 1. The application can form an electrostatic field on the surface of the adsorption layer, so as to achieve the effect of adsorbing the wafer, since the electrode group A contact point and the electrode group B contact point are respectively in electrical contact with the electrode group A and the electrode group B, the adsorption layer can be directly replaced by disassembling the whole, and the electrode group A contact point and the electrode group B contact point will not be damaged during replacement, thereby reducing the maintenance period and reducing the application cost of the electrostatic chuck.

[0015] 2. The application can form an electrostatic field on the surface of the adsorption layer, so as to achieve the effect of adsorbing the wafer, since the electrode group A contact point and the electrode group B contact point are respectively in electrical contact with the electrode group A and the electrode group B, the adsorption layer can be directly replaced by disassembling the whole, and the electrode group A contact point and the electrode group B contact point will not be damaged during replacement, thereby reducing the maintenance period and reducing the application cost of the electrostatic chuck. BRIEF DESCRIPTION OF DRAWINGS

[0016] Other features, objects, and advantages of the application will become more apparent from the following detailed description of non-limiting embodiments, read in conjunction with the accompanying drawings:

[0017] Figure 1 is a front plane schematic diagram of the semiconductor electrostatic chuck and the preparation method of the application;

[0018] Figure 2 is a front plane schematic diagram of the semiconductor electrostatic chuck and the preparation method of the application;

[0019] Figure 3 is a front plane schematic diagram of the semiconductor electrostatic chuck and the preparation method of the application;

[0020] Figure 4 is a position schematic diagram of the insulating adhesive of the semiconductor electrostatic chuck and the preparation method of the application.

[0021] In the figure: 1, adsorption layer; 2, base; 3a, inner ring cooling gas groove; 3b, inner ring cooling air channel; 4a, outer ring cooling gas groove; 4b, outer ring cooling air channel; 5, jacking column hole; 6, mounting hole; 7, positioning pin hole; 101, electrode group A contact point; 102, electrode group B contact point; 110, cooling gas input port; 300, electrode group; 301, electrode group A; 302, electrode group B; 404, insulating adhesive. DETAILED DESCRIPTION

[0022] In order to make the technical means, creative features, purposes and effects of the application easy to understand, the following specific embodiments are further described.

[0023] In the description of the present application, it needs to be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship 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, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application; In the description of the present application, it needs to be explained that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "setting" should be understood in a broad sense, for example, it can be fixedly connected, set, or detachably connected, set, or integrally connected, set. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0024] Please refer to Figures 1-4 The present application provides a technical solution: a semiconductor electrostatic chuck and a preparation method, comprising a base 2, the top surface of the base 2 is provided with a mounting hole 6, the top surface of the base 2 is fixedly provided with an adsorption layer 1, the surface of the adsorption layer 1 is provided with an outer ring cooling gas groove 4a, an outer ring cooling gas channel 4b, an inner ring cooling gas groove 3a and an inner ring cooling gas channel 3b, the outer ring cooling gas groove 4a is connected with the outer ring cooling gas channel 4b in communication, the inner ring cooling gas groove 3a is connected with the inner ring cooling gas channel 3b in communication, the outer ring cooling gas channel 4b is located outside the inner ring cooling gas channel 3b, the surface of the adsorption layer 1 is provided with a jacking column hole 5, the inside of the adsorption layer 1 is fixedly provided with an electrode group 300, the inside of the electrode group 300 is fixedly provided with an electrode group A 301 and an electrode group B 302, the bottom surface of the adsorption layer 1 is fixedly provided with an electrode group A contact 101 and an electrode group B contact 102, the electrode group A contact 101 is in electrical contact with the electrode group A 301, the electrode group B contact 102 is in electrical contact with the electrode group B 302, and the bottom surface of the base 2 is provided with a positioning pin hole 7.

[0025] In this embodiment, the base 2 is made of aluminum alloy material, and its surface is treated by hard sulfuric acid anode or ceramic thermal spraying to avoid oxidation of the base 2 and generation of particles when the base 2 is directly exposed to the plasma halogen environment. The surface treatment of the base 2 has excellent heat resistance, oxidation resistance, corrosion resistance, and aging resistance. The outer part of the adsorption layer 1 is made of polyimide, polytetrafluoroethylene, polyurethane, silicone rubber, or other insulating materials. The electrode group A 301 and the electrode group B 302 are direct current high voltage electrode groups made of one or more conductor materials such as copper foil, silver foil, gold foil, etc. The electrode group A contact 101 and the electrode group B contact 102 are connected to the equipment by wires. The outer part of the electrode group A contact 101 and the electrode group B contact 102 is made of polyimide, polytetrafluoroethylene, polyurethane, silicone rubber, or other insulating materials. Since the electrode group A contact 101 and the electrode group B contact 102 are in electrical contact with the electrode group A 301 and the electrode group B 302, respectively, the electrode group A 301 and the electrode group B 302 are in a charged state. The electrode group A 301 and the electrode group B 302 generate a polarization effect on the marked wafer on the adsorption layer 1, producing mutual electrostatic attraction, thereby achieving the effect of adsorbing the wafer. When the electrode group A 301 and the electrode group B 302 inside the adsorption layer 1 are damaged, the adsorption layer 1 can be directly removed and replaced without damaging the electrode group A contact 101 and the electrode group B contact 102, thereby reducing the maintenance period and the application cost of the electrostatic chuck. The cooling gas input port 110 is connected to the external cooling gas pipe. After the cooling gas is introduced into the cooling gas input port 110, the cooling gas is transmitted to the inner ring cooling gas channel 3a and the outer ring cooling gas channel 4a through the inner ring cooling gas channel 3b and the outer ring cooling gas channel 4b, respectively, thereby cooling the adsorption layer 1 and the wafer in multiple units to maintain the optimal contact state of the adsorption layer 1 and the wafer and improve the stability of the device during the adsorption process. The inner ring cooling gas channel 3a and the outer ring cooling gas channel 4a are in a rectangular state in the process stage, and the surface is concave, which can store a certain amount of cooling gas and provide more contact area for the cooling gas and the wafer. The upper edge of the section is transitioned with a round corner, which is beneficial to avoid the cooling channel being too sharp and achieve the effect of protecting the contact wafer. The electrode group B 302 and the electrode group A 301 are filled with insulating adhesive 404 to enhance the insulation performance between the electrode group A 301 and the electrode group B 302. The original solution of the insulating adhesive 404 adds ion migration resistant agent in a ratio of 1:0.2, and is coated on the electrode group A 301 and the electrode group B 302 with a thickness of 90 μm. The electrode group A 301 and the electrode group B 302 are completely filled with the adhesive. The insulating adhesive 404 is a thermosetting adhesive, and the electrode group A 301 and the electrode group B 302 are laminated with a polyimide film to obtain the adsorption layer 1 in a temperature environment not higher than 200 degrees Celsius.In the embodiment, the polyimide film is enhanced in the bonding force with the insulating adhesive 404 through the plasma surface modification technology, the positioning pin hole 7 arranged at the bottom of the base 2 facilitates the inlay connection with the positioning pin of the equipment, and the installation of the base 2 is facilitated.

[0026] In an optional embodiment, the electrode group B 302 and the electrode group A 301 are both annular, the electrode group B 302 is located inside the electrode group A 301, the spacing between the electrode group B 302 and the electrode group A 301 is 80 μm, the electrode group B 302 and the electrode group A 301 are filled with the insulating adhesive 404, the thickness of the insulating adhesive 404 is 90 μm, and the filling of the insulating adhesive 404 between the electrode group B 302 and the electrode group A 301 can enhance the insulation performance between the electrode group A 301 and the electrode group B 302.

[0027] In the embodiment, the top surfaces of the inner ring cooling gas groove 3a and the outer ring cooling gas groove 4a are both provided with concave surfaces, the end surfaces of the inner ring cooling gas groove 3a and the outer ring cooling gas groove 4a are both provided with round corners, the cross sections of the inner ring cooling gas groove 3a and the outer ring cooling gas groove 4a are in a rectangular state when they are in a process stage, the concave surfaces can store a certain amount of cooling gas, and the concave surfaces can provide more contact area for the cooling gas and the wafer, and the upper edge of the cross section is transitioned by the round corner, which is beneficial to avoid that the cooling groove is too sharp and achieve the effect of protecting the contact wafer.

[0028] In the embodiment, the cooling gas input port 110 is arranged in the middle of the adsorption layer 1, the cooling gas input port 110 is respectively connected with the inner ring cooling gas channel 3b and the outer ring cooling gas channel 4b, the input end of the cooling gas input port 110 is located in the middle of the base 2, the cooling gas input port 110 is communicated with the external cooling gas pipe, after the cooling gas input port 110 is input with the cooling gas, the cooling gas is respectively transmitted to the inner ring cooling gas groove 3a and the outer ring cooling gas groove 4a through the inner ring cooling gas channel 3b and the outer ring cooling gas channel 4b, so as to perform multi-unit cooling on the adsorption layer 1 and the wafer, keep the contact surface of the adsorption layer 1 and the wafer in the best contact state, and improve the stability in the adsorption process of the device.

[0029] In the use of the semiconductor electrostatic chuck and the preparation method, it should be pointed out that the present application is a semiconductor electrostatic chuck and a preparation method, which comprises 1, an adsorption layer; 2, a base; 3a, an inner ring cooling gas groove; 3b, an inner ring cooling gas channel; 4a, an outer ring cooling gas groove; 4b, an outer ring cooling gas channel; 5, a jacking column hole; 6, a mounting hole; 7, a positioning pin hole; 101, an electrode group A contact; 102, an electrode group B contact; 110, a cooling gas input port; 300, an electrode group; 301, an electrode group A; 302, an electrode group B; 404, an insulating adhesive, all components are general standard components or components known to those skilled in the art, and the structure and principle thereof can be known by technical personnel through technical manuals or through conventional experimental methods.

[0030] In use, the electrode group A contact 101 and the electrode group B contact 102 are powered with the equipment, the electrode group A contact 101 and the electrode group B contact 102 are respectively in electrical contact with the electrode group A 301 and the electrode group B 302, so that the electrode group A 301 and the electrode group B 302 are both in a charged state, the electrode group A 301 and the electrode group B 302 produce a polarization effect on the marked wafer on the adsorption layer 1, generating mutual electrostatic attraction, thereby achieving the effect of adsorbing the wafer, when the electrode group A 301 and the electrode group B 302 inside the adsorption layer 1 are damaged, the adsorption layer 1 can be directly disassembled, and the electrode group A contact 101 and the electrode group B contact 102 will not be damaged during the replacement process, the cooling gas input port 110 is connected with the external cooling gas pipe, after the cooling gas input port 110 is connected with the external cooling gas pipe, the cooling gas is transmitted to the inner ring cooling gas groove 3a and the outer ring cooling gas groove 4a through the inner ring cooling gas channel 3b and the outer ring cooling gas channel 4b, thereby multi-unit cooling the adsorption layer 1 and the wafer, the electrode group B 302 and the electrode group A 301 are filled with an insulating adhesive 404, which can enhance the insulation performance between the electrode group A 301 and the electrode group B 302, by controlling the power-off of the electrode group B 302 and the electrode group A 301, and by introducing positive pressure gas into the inner ring cooling gas groove 3a and the outer ring cooling gas groove 4a, the vacuum state of the wafer and the adsorption layer 1 can be broken, and the wafer can be easily removed.

[0031] The basic principles and main features of the present application and the advantages of the present application have been shown and described above, and it is obvious for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, and the scope of the present application is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0032] Furthermore, it should be understood that although the description is made according to the embodiments, not every embodiment contains only one independent technical solution, and the description is made in this way only for the sake of clarity, and the person skilled in the art should consider the description as a whole, and the technical solutions in each embodiment can also be combined appropriately to form other embodiments that the person skilled in the art can understand.

Claims

1. A semiconductor electrostatic chuck, comprising a base (2), characterized in that: The base (2) has mounting holes (6) on its top surface. An adsorption layer (1) is fixedly mounted on the top surface of the base (2). The adsorption layer (1) has an outer ring cooling air groove (4a), an outer ring cooling air channel (4b), an inner ring cooling air groove (3a), and an inner ring cooling air channel (3b) on its surface. The outer ring cooling air groove (4a) is connected to the outer ring cooling air channel (4b), and the inner ring cooling air groove (3a) is connected to the inner ring cooling air channel (3b). The outer ring cooling air channel (4b) is located outside the inner ring cooling air channel (3b). The adsorption layer (1) The surface is provided with lifting column holes (5), and an electrode group (300) is fixedly installed inside the adsorption layer (1). Electrode group A (301) and electrode group B (302) are fixedly installed inside the electrode group (300). Electrode group A contact (101) and electrode group B contact (102) are fixedly installed on the bottom surface of the adsorption layer (1). Electrode group A contact (101) is in electrical contact with electrode group A (301), and electrode group B contact (102) is in electrical contact with electrode group B (302). The bottom surface of the base (2) is provided with positioning pin holes (7). Both electrode group B (302) and electrode group A (301) are ring-shaped. Electrode group B (302) is located inside electrode group A (301), and the distance between electrode group B (302) and electrode group A (301) is 80 μm. The top surfaces of both the inner ring cooling air groove (3a) and the outer ring cooling air groove (4a) are provided with concave surfaces, and the end faces of both the inner ring cooling air groove (3a) and the outer ring cooling air groove (4a) are provided with rounded corners.

2. The semiconductor electrostatic chuck according to claim 1, characterized in that: An insulating adhesive (404) with a thickness of 90 μm is filled between electrode group B (302) and electrode group A (301).

3. A semiconductor electrostatic chuck according to claim 1, characterized in that: The adsorption layer (1) has a cooling gas inlet (110) in the middle. The cooling gas inlet (110) is connected to the inner ring cooling air channel (3b) and the outer ring cooling air channel (4b) respectively. The input end of the cooling gas inlet (110) is located in the middle of the base (2).

4. A method for preparing a semiconductor electrostatic chuck according to any one of claims 1-3: characterized in that, The process includes the following steps: providing an electrostatic chuck, the electrostatic chuck including a base (2) and an adsorption layer (1) disposed on the base (2), the base (2) being made of aluminum alloy material, the surface of which is treated with hard sulfuric acid anodizing or ceramic thermal spraying, the adsorption layer (1) being made of polyimide, polytetrafluoroethylene, polyurethane or silicone rubber material on the outside, and an electrode group (300) being disposed inside the adsorption layer (1) with mutual staggered crosses, the electrode group (300) being made of copper foil, silver foil or gold foil material.

5. A method for preparing a semiconductor electrostatic chuck according to claim 4: characterized in that: The electrode group (300) includes an electrode group A contact (101) and an electrode group B contact (102), and the electrode group A contact (101) and the electrode group B contact (102) penetrate the base (2). The upper ends of the components of the electrode group A contact (101) and the electrode group B contact (102) are in contact with the electrode group A (301) and the electrode group B (302) respectively. The lower ends of the components of the electrode group A contact (101) and the electrode group B contact (102) are fixed on the base (2). The outer surface of the electrode group A contact (101) and the electrode group B contact (102) is made of polyimide, polytetrafluoroethylene, polyurethane or silicone rubber.

6. A method for preparing a semiconductor electrostatic chuck according to claim 5: characterized in that: The adsorption layer (1) has two sets of interconnected inner ring cooling gas grooves (3a) and outer ring cooling gas grooves (4a) on the contact surface with the wafer. The inner ring cooling gas grooves (3a) and outer ring cooling gas grooves (4a) are both distributed in a ring shape at equal intervals. The upper edge of the cross-section of the inner ring cooling gas grooves (3a) and outer ring cooling gas grooves (4a) are both rounded.

7. A method for preparing a semiconductor electrostatic chuck according to claim 6: characterized in that: The inner ring cooling gas groove (3a) and the outer ring cooling gas groove (4a) are both rectangular in cross-section, and the surface of the cooling gas groove is treated with hard sulfuric acid anodizing or ceramic thermal spraying.

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