Electrostatic adsorption tool and surface processing method for objects

Abstract

To keep adsorption of a thin object for a long time in a wet environment.SOLUTION: In an electrostatic adsorption tool A1 including an electrostatic adsorption force generating member 30 that embeds electrode element groups 302 and 303 inside an electrical insulating layer 301 and electrostatically adsorbs a thin object 10 by applying a voltage to the electrode element groups 302 and 303, the electrostatic adsorption force generating member 30 includes a first water-repellent insulating layer 305 made of a water-repellent material at least on an adsorption surface that adsorbs the thin object 10.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an electrostatic adsorption tool for adsorbing and holding an object, and a method for processing the surface of an object by performing processing on the surface of the object in an electrostatic adsorption state.

Background Art

[0002] Conventionally, as an electrostatic chuck using Coulomb force, there is known one including a ceramic base, an insulating layer formed on one main surface of the ceramic base and having an adsorption surface for adsorbing an insulating substrate, and a pair of electrodes formed between the ceramic base and the insulating layer. The insulating layer is the same ceramic sintered body as the ceramic base, the thickness of the insulating layer is 0.001 mm or more and 0.1 mm or less, and the distance between the pair of electrodes is 0.3 mm or more and 2.5 mm or less (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the prior art described in Patent Document 1 above, the adsorption surface for adsorbing a thin object to the electrostatic chuck has a configuration in which an insulating layer (ceramic sintered body) is provided. Therefore, in a wet (high humidity) environment, adsorption can be maintained for a short time, but there is a problem that when the time becomes long, the holding force decreases and the adsorption of the thin object cannot be maintained.

[0005] The present invention has been made paying attention to the above problems, and an object thereof is to continuously maintain the adsorption of a thin object in a wet environment for a long time.

Means for Solving the Problems

[0006] To achieve the above objective, the electrostatic adsorption tool of the present invention comprises an electrostatic adsorption force generating member that has a group of electrode elements embedded inside an electrical insulating layer and electrostatically adsorbs a thin object by applying a voltage to the group of electrode elements. The electrostatic adsorption force generating member has a water-repellent layer made of a water-repellent material on at least the adsorption surface that adsorbs the thin object. The electrostatic adsorption force generating member is provided with an adsorption force control unit that can be connected to and disconnected from the group of electrode elements. The adsorption force control unit is cordless, connecting to the electrostatic adsorption force generating member when adsorbing the thin object, disconnecting from the electrostatic adsorption force generating member after adsorbing the thin object, and maintaining the generation of electrostatic adsorption force by the charge accumulated in the electrostatic adsorption force generating member. When the electrostatic adsorption tool is introduced into a surface processing apparatus that includes processes in a wet environment, the adsorption force control unit is disconnected from the electrostatic adsorption force generating member, creating a unit state that can be independently transported while still adsorbing the thin object. Invention 1 provides the electrostatic adsorption force generating member, comprising a base plate and an electrical insulating layer in which a group of electrode elements are embedded. The water-repellent layer is a first water-repellent insulating layer set on the object adsorption side of the electrical insulating layer. Invention 2 provides the electrostatic adsorption force generating member, comprising a base plate and an electrical insulating layer in which a group of electrode elements are embedded. The water-repellent layer is a second water-repellent insulating layer set by replacing the entire electrical insulating layer. [Effects of the Invention]

[0007] By employing the above-mentioned solution, moisture absorption is suppressed by the water-repellent layer even in wet environments, maintaining retention even over long periods, and allowing for sustained adsorption of thin objects. As a result, it is now possible to maintain the adsorption of thin objects for extended periods in wet processes, improving the processing capacity of each wet process. Invention 1 allows for the easy manufacture of an electrostatic adsorption tool having water-repellent properties in a wet environment due to a first water-repellent insulating layer, by adding it to an existing electrostatic adsorption tool as a base. Invention 2 allows for the manufacture of an electrostatic adsorption tool having water-repellent properties in a wet environment due to a second water-repellent insulating layer, by a simple structure that omits the electrical insulating layer. In addition, by extending the second water-repellent insulating layer to the embedded area of ​​the electrode element group, a higher moisture absorption suppression effect can be obtained compared to the first water-repellent insulating layer. [Brief explanation of the drawing]

[0008] [Figure 1] This is a plan view showing the electrostatic adsorption tool A1 of Example 1. [Figure 2] This is a longitudinal cross-sectional view showing the electrostatic adsorption tool A1 of Example 1. [Figure 3] This is a detailed diagram showing an enlarged configuration and adsorption force control unit of the electrostatic adsorption tool A1 of Example 1. [Figure 4] This is an explanatory diagram illustrating the principle of electrostatic attraction force generation by an electrostatic chuck. [Figure 5] This is an explanatory diagram of a surface processing method for an object, showing an example of spin etching, which is a surface processing method using the thin object holding unit U of Example 1. [Figure 6] This is an explanatory diagram illustrating the adsorption effect of thin objects when moisture absorption is present, as in previous examples. [Figure 7] This is an explanatory diagram showing the adsorption effect of a thin object when the effect of moisture absorption is eliminated in Example 1. [Figure 8] This is a detailed diagram showing an enlarged configuration and adsorption force control unit of the electrostatic adsorption tool A2 of Example 2. [Best Mode for Carrying Out the Invention]

[0009] Hereinafter, embodiments for carrying out the electrostatic adsorption tool and object surface processing method according to the present invention will be described based on the drawings of Example 1 and Example 2. [Example 1]

[0010] The electrostatic adsorption tool in Example 1 uses a wafer, which is the material for an IC chip (semiconductor integrated circuit), as the target object. The target object surface processing method is applied to a group of semiconductor manufacturing equipment that manufactures individual semiconductor chips (dies) by applying various surface processing techniques to the surface of the target object in an adsorbed state to create circuit patterns such as fine wiring and elements. The "configuration of electrostatic adsorption tool A1" and the "target object surface processing method" will be described below.

[0011] [Configuration of electrostatic adsorption tool A1 (Figures 1-4)] As shown in Figures 1 to 3, the electrostatic adsorption tool A1 comprises a thin object 10, an electrostatic adsorption force generating member 30, and an adsorption force control unit 40.

[0012] The thin object 10 is a circular thin plate object with a thickness of 0.5 mm or less, and a "wafer" made of a thin circular plate formed of a semiconductor material crystal is taken as a typical object. Here, as the "wafer", in addition to the most common silicon wafer, silicon carbide wafers, sapphire wafers, and compound semiconductor wafers (gallium phosphide wafers, gallium arsenide wafers, indium phosphide wafers, gallium nitride wafers, etc.) are included. Further, the "wafer" also includes a glass wafer used as a support substrate.

[0013] The electrostatic adsorption force generating member 30 generates an adsorption force using an electrostatic field and exhibits a function of generating an adsorption force for adsorbing and holding the thin object 10. As shown in FIG. 3, the electrostatic adsorption force generating member 30 has a configuration including an electric insulating layer 301, electrode element groups 302 and 303, a base plate 304, and a first water-repellent insulating layer 305 (water-repellent layer).

[0014] The electric insulating layer 301 is provided on the base plate 304 and is an electrical insulating layer in which electrode element groups 302 and 303 in which plus electrodes and minus electrodes are alternately arranged are embedded inside.

[0015] The first water-repellent insulating layer 305 is a layer set on the object adsorption side of the electric insulating layer 301 using a fluorine material as a water-repellent material. The first water-repellent insulating layer 305 has an adsorption surface 305a for electrostatically adsorbing the thin object 10. Therefore, the adsorption surface 305a for adsorbing the thin object 10 is a surface formed by a water-repellent layer made of a water-repellent material. Here, "water repellency" refers to the property of repelling water on the surface.

[0016] As shown in FIG. 3, the adsorption force control unit 40 is provided so as to be connectable and disconnectable to / from the electrode element groups 302 and 303 of the electrostatic adsorption force generating member 30. The adsorption force control unit 40 controls the generation and disappearance of the electrostatic adsorption force by connecting to the electrode element groups 302 and 303, and even if it is disconnected from the electrode element groups 302 and 303 after generating the electrostatic adsorption force, the generation of the electrostatic adsorption force is maintained by the charges accumulated in the electrostatic adsorption force generating member 30. That is, the adsorption force control unit 40 is not a corded method that is always connected to the electrode element groups 302 and 303 by a lead wire or the like, but a cordless method that is disconnected from the electrostatic adsorption force generating member 30 when the electrostatic adsorption force generating member 30 accumulates charges.

[0017] Here, in the case of the cordless method, when adsorbing the thin object 10, the adsorption force control unit 40 is connected to the electrostatic adsorption force generating member 30, and the thin object 10 is electrostatically adsorbed by applying a voltage to the electrode element groups 302 and 303. Then, when the generation of the electrostatic adsorption force is confirmed, thereafter, the adsorption force control unit 40 is disconnected from the electrostatic adsorption force generating member 30, and the generation of the electrostatic adsorption force is maintained by the charges accumulated in the electrostatic adsorption force generating member 30.

[0018] As shown in FIG. 3, the adsorption force control unit 40 includes a first switch SW1 that controls the conduction between the electrode element group 302 and the ground, a second switch SW2 that controls the voltage application to the electrode element group 302, a third switch SW3 that controls the voltage application with the opposite polarity to the voltage applied by the second switch SW2, a fourth switch SW4 that controls the conduction between the electrode element group 303 and the ground, a fifth switch SW5 that controls the voltage application to the electrode element group 303, and a sixth switch SW6 that controls the voltage application with the opposite polarity to the voltage applied by the fifth switch SW5.

[0019] In its initial state, the suction force control unit 40 has all switches SW1, SW2, SW3, SW4, SW5, and SW6 turned off. When generating electrostatic attraction force, the suction force control unit 40 is connected to the electrostatic attraction force generating member 30, and the electrostatic attraction force is generated by controlling the on / off state of each switch. After that, the suction force control unit 40 is disconnected from the electrostatic attraction force generating member 30. Even after disconnection, the generation of electrostatic attraction force is maintained for a long period of time. Therefore, when releasing the electrostatic attraction force, the suction force control unit 40 is connected to the electrostatic attraction force generating member 30 again, and the electrostatic attraction force is released by controlling the on / off state of each switch.

[0020] Next, the principle of electrostatic attraction force generation in the electrostatic attraction force generating member 30 will be explained based on Figure 4. The electrostatic attraction force generating member 30 used in Example 1 is an example of an "electrostatic chuck" that electrostatically attracts an object by Coulomb force. As shown in Figure 4, when a voltage is applied to the electrodes, surface polarization is induced on the surface of the object. Here, negative surface polarization is induced on the surface of the object opposite to the electrode portion to which a positive voltage is applied. Also, positive surface polarization is induced on the surface of the object opposite to the electrode portion to which a negative voltage is applied. Then, an electrostatic field is formed between the electrode surface and the surface of the object by an arc-shaped flow from the positive electrode through the surface of the object to the negative electrode, and this electrostatic field generates an electrostatic attraction force that attracts the object to the surface of the insulating layer.

[0021] When releasing the electrostatic attraction force, as shown in Figure 4, the applied voltage to the electrodes is cut off, and the object returns to its original state (the electrostatic chuck and the object are separated), without transferring any charge to the object. The reason why cutting off the applied voltage to the electrodes does not transfer any charge to the object is that the applied voltage induces the electrostatic attraction force through the surface polarization of the object, and when the applied voltage to the electrodes is cut off, the surface polarization of the object also disappears.

[0022] [Surface processing method for the target object (Figure 5)] As described above, the electrostatic adsorption force generating member 30 uses a cordless system in which the adsorption force control unit 40 is separated from the electrostatic adsorption force generating member 30. Therefore, the electrostatic adsorption tool A1 can be placed into a surface processing apparatus that includes processes in a wet (high humidity) environment in a unit state that allows for independent transport while still adsorbing the thin object 10. The surface processing method of the object is executed when it is placed into this surface processing apparatus. Below, an example of etching using a spin etching apparatus 50, which is an example of surface processing using the thin object holding unit U, will be explained with reference to Figure 5.

[0023] A method for surface processing an object using a thin object holding unit U in which a thin object 10 is electrostatically attracted to an electrostatic attraction force generating member 30, comprising an internal transfer step to a spin etching apparatus 50, a spin etching processing step, and an external transfer step from the spin etching apparatus 50.

[0024] The internal transfer step involves transferring and setting the thin object holding unit U inside a spin etching apparatus 50 (an example of a surface processing apparatus that includes a wet environment process) that generates circuits by corrosion. Here, the spin etching apparatus 50 is a device used in semiconductor manufacturing to corrode and remove unnecessary thin films other than the necessary circuit parts exposed in pretreatment using a dropped solvent. As shown in Figure 5, the spin etching apparatus 50 includes, for example, a unit support base 51, a support base support shaft 52, a motor 53, a cleaning water receiving container 54, and a cleaning water spray nozzle 55, and the thin object holding unit U is set on the unit support base 51.

[0025] The spin etching step involves applying a circuit generation process to a set thin object holding unit U, utilizing corrosion to generate a desired circuit. This circuit generation process includes a photomask creation step, a pre-etching cleaning step, a resist coating step, an exposure step, a resist removal step, an etching step, a cured resist removal step, and a post-etching cleaning step. The pre-etching cleaning step and the post-etching cleaning step are processes performed in a wet environment using a cleaning solution. Furthermore, in addition to these cleaning steps, processes performed using various liquids other than cleaning solutions, such as the resist coating step, resist removal step, and etching step, are also included in processes performed in a wet environment.

[0026] In the external transfer step, once the spin etching process is complete, the thin workpiece holding unit U is removed from the internal processing position of the spin etching apparatus 50 while still holding the processed thin workpiece 10, and the workpiece is transferred to the outside of the spin etching apparatus 50.

[0027] Here, if the thin object 10 with the film deposition process is to be separated from the electrostatic adsorption force generating member 30 after being transferred to the outside of the spin etching apparatus 50, the adsorption force control unit 40 is connected at the external transfer destination to release the electrostatic adsorption force. On the other hand, if the film deposition process is part of a continuous surface processing process, the thin object 10 is transferred to the next surface processing apparatus located outside the spin etching apparatus 50 while still in the thin object 10 holding unit U. Furthermore, if the next surface processing apparatus is on the opposite side of the film deposition surface, the electrostatic adsorption force is released, the front and back sides of the thin object 10 are reversed, and then the electrostatic adsorption force is generated again to electrostatically adsorb the thin object 10, and the film deposition process is performed on the back side of the thin object 10.

[0028] Thus, the surface processing method for an object aims to perform surface processing on a thin object 10, which maintains an electrostatic adsorption state even in a wet environment, by using a thin object holding unit U composed of a thin object 10 and an electrostatic adsorption force generating member 30. Therefore, surface processing equipment that includes processes in a wet environment is not limited to the spin etching apparatus 50 that realizes circuit generation by corrosion, but also of course includes wet etching apparatuses, spin cleaning apparatuses, printing and coating apparatuses, etc., which include wet (high humidity) processes in the semiconductor device manufacturing process.

[0029] Wet etching equipment uses chemical corrosion to remove unwanted thin films from areas other than the required circuitry without rotation, and includes cleaning steps before and after the etching process. Spin cleaning equipment cleans with a cleaning solution while rotating, removing particles (tiny dust invisible to the naked eye), oil, and other contaminants. Printing and coating equipment generates insulating films, metal films, protective films, etc., by screen printing, and includes cleaning steps before and after the printing process. Furthermore, it is possible to improve processing performance regardless of which equipment is applied.

[0030] Next, we will explain the "background technologies and solutions to the challenges."

[0031] [Background technology and problem-solving strategies (Figures 6 and 7)] In recent years, objects requiring precision processing have become thinner, making it difficult to handle these thin objects whose strength has been reduced. To process these thin objects without damage during precision processing, reinforcement such as suction holding tools is essential. Furthermore, thin objects that exhibit significant warping due to thinning require correction of the warp using suction holding tools. Precision processing involves special environments such as wet (high humidity), high temperature, and vacuum environments, severely limiting the types of suction holding tools that can be used. To proceed with processing in precision processes, the suction holding tool must maintain adhesion for extended periods (e.g., two weeks) while reinforcing the thin object.

[0032] In electrostatic adsorption tools, thin objects can be adsorbed and maintained for extended periods in atmospheric and vacuum environments. However, in wet (high humidity) environments, while adsorption can be maintained for short periods, the holding power decreases significantly over extended periods, making it impossible to maintain adsorption.

[0033] For example, in the prior art described in Patent Document 1 above, as shown in Figure 6, the adsorption surface that adsorbs a thin object to the electrostatic chuck is an insulating layer (ceramic sintered body). Therefore, in a wet (high humidity) environment, adsorption can be maintained for a short time, but over a long period of time, the holding force f decreases, and as shown in Figure 6, the thin object peels off from the adsorption surface.

[0034] In response, the inventors investigated the cause of the decrease in holding power in wet (high humidity) environments. As a result of experiments, they found that the electrostatic adsorption tool gradually decreases in adsorption power because it can no longer maintain a normal electric field when it absorbs moisture. Furthermore, they confirmed that thin objects can be adsorbed and held for a long time by using a water-repellent material in the electrostatic adsorption tool to suppress moisture absorption. They also confirmed that contamination is reduced when a fluorine material is used as the water-repellent material due to its antifouling effect.

[0035] Therefore, based on the above findings and confirmations, the electrostatic adsorption force generating member 30 was configured to have a first water-repellent insulating layer 305 set on the object adsorption side of the electrical insulating layer 301, as shown in Figure 7. As a result, even in a wet (high humidity) environment, moisture absorption is suppressed by the first water-repellent insulating layer 305, and as shown in Figure 7, the holding force F is maintained even over a long period of time, allowing the adsorption of the thin object 10 to be maintained for an extended period of time.

[0036] As a result, in wet (high humidity) processes such as spin etching, spin cleaning, and coating, it became possible to continuously adsorb and maintain thin objects for extended periods, improving the processing capacity of each wet (high humidity) process.

[0037] As described above, the electrostatic adsorption tool A1 and the object surface processing method of Example 1 provide the following effects.

[0038] (1) An electrostatic adsorption tool A1 comprising an electrostatic adsorption force generating member 30 which has electrode element groups 302 and 303 embedded inside an electrical insulating layer 301 and electrostatically adsorbs a thin object 10 by applying a voltage to the electrode element groups 302 and 303, wherein the electrostatic adsorption force generating member 30 has a water-repellent layer (first water-repellent insulating layer 305) made of a water-repellent material on at least the adsorption surface that adsorbs the thin object 10. Therefore, the adsorption of the thin object 10 can be maintained for a long period of time in a wet environment.

[0039] (2) The electrostatic adsorption force generating member 30 has a base plate 304 and an electrical insulating layer 301 in which electrode element groups 302 and 303 are embedded inside, and the water-repellent layer is a first water-repellent insulating layer 305 set on the object adsorption side of the electrical insulating layer 301. Therefore, an electrostatic adsorption tool A1 having a water-repellent function in a wet environment due to the first water-repellent insulating layer 305 can be easily manufactured by adding it to an existing electrostatic adsorption tool as a base.

[0040] (3) The water-repellent layer (first water-repellent insulating layer 305) uses a fluorine material as the water-repellent material. Therefore, the antifouling effect of the fluorine material reduces contamination of the thin object 10 that is adsorbed. In addition, the antifouling effect improves the cleanliness of the electrostatic adsorption tool A1. Furthermore, the antifouling effect makes it possible to easily remove the formed film that adheres to the electrostatic adsorption tool A1 during the thin film formation process.

[0041] (4) The thin object 10 shall be a thin plate-like object with a thickness of 0.5 mm or less. Therefore, as objects requiring precision processing become thinner, wafers such as silicon wafers that are neatly and tightly held in place solely by electrostatic adsorption utilizing Coulomb force can be included in the thin object 10.

[0042] (5) The electrostatic force generating member 30 is provided with an adsorption force control unit 40 that can be connected to and disconnected from the electrode element groups 302 and 303. The adsorption force control unit 40 is a cordless type that connects to the electrostatic force generating member 30 when adsorbing a thin object 10, and disconnects from the electrostatic force generating member 30 after adsorbing the thin object 10. Therefore, with the thin object 10 electrostatically attracted, the thin object 10 and the electrostatic attraction force generating member 30 form an independent thin object holding unit U, which can be easily transferred to and attached to a surface processing device.

[0043] (6) The thin object holding unit U, which is composed of an electrostatic adsorption force generating member 30 that electrostatically adsorbs the thin object 10, is transferred to a surface processing apparatus (spin etching apparatus 50, etc.) that includes a wet environment process, the thin object holding unit U is set at an internal processing position in the surface processing apparatus (spin etching apparatus 50, etc.) and surface processing is performed, and when the surface processing is completed the thin object holding unit U is transferred from the surface processing apparatus (spin etching apparatus 50, etc.) to the outside of the apparatus while still holding the surface-processed thin object 10. Therefore, by using an independent thin object holding unit U composed of a thin object 10 and an electrostatic adsorption force generating member 30, surface processing can be performed in a surface processing apparatus (such as a spin etching apparatus 50) that includes processes in a wet environment while maintaining the adsorption of the thin object 10. In addition, by applying it to a surface processing apparatus (such as a spin etching apparatus 50) that includes processes in a wet environment, processing performance can be improved. [Example 2]

[0044] Example 2 is an example of an electrostatic adsorption tool A2 equipped with an electrostatic adsorption force generating member in which the entire electrical insulating layer is a water-repellent layer.

[0045] As shown in Figure 8, the electrostatic adsorption force generating member of Example 2 comprises electrode element groups 302 and 303 (positive electrode 302, negative electrode 303), a base plate 304, and a second water-repellent insulating layer 306 (water-repellent layer).

[0046] The second water-repellent insulating layer 306 is provided on the base plate 304 and is a layer that serves as both an electrical insulating layer and a water-repellent layer, with electrode element groups 302 and 303, in which positive and negative electrodes are arranged alternately, embedded inside. In other words, the second water-repellent insulating layer 306 is a layer that is set up by replacing the entire electrical insulating layer. Furthermore, the second water-repellent insulating layer 306 uses a fluorine material as the water-repellent material, similar to the first water-repellent insulating layer 305 in Example 1, and has an adsorption surface 306a that electrostatically adsorbs the thin object 10. Therefore, the adsorption surface 306a that adsorbs the thin object 10 becomes a water-repellent layer made of the water-repellent material.

[0047] Note that the other configurations in Example 2, as well as the surface processing method for the object, are the same as in Example 1, and therefore their illustrations and descriptions are omitted.

[0048] As described above, the electrostatic adsorption tool A2 and the object surface processing method of Example 2 provide the following effects in addition to the effects of (1), (3), (4), (5), and (6) of Example 1.

[0049] (7) The electrostatic adsorption force generating member 30 has a base plate 304 and an electrical insulating layer in which electrode element groups 302 and 303 are embedded inside, and the water-repellent layer is a second water-repellent insulating layer 306 which is set by replacing the entire electrical insulating layer. Therefore, the electrostatic adsorption tool A2, which has a water-repellent function in a wet environment due to the second water-repellent insulating layer 306, can be manufactured with a simple structure that omits the electrical insulating layer. In addition, by extending the second water-repellent insulating layer 306 to the embedded area of ​​the electrode element group 302, 303, a higher moisture absorption suppression effect can be obtained than that of the first water-repellent insulating layer 305.

[0050] The electrostatic adsorption tool and object surface processing method of the present invention have been described above based on Examples 1 and 2. However, the specific configuration is not limited to these examples, and changes in design or additions to the configuration are permitted as long as they do not deviate from the gist of the invention as described in each claim of the patent.

[0051] Examples 1 and 2 show examples where a wafer, which is the material for an IC chip (semiconductor integrated circuit), is used as the thin object 10. However, the thin object is not limited to wafers. For example, it could be a film or the like, where a decrease in retention force due to electrostatic adsorption tools is a problem in processing equipment in a wet environment.

[0052] Example 1 shows an example of a first water-repellent insulating layer 305 set on the object adsorption side of the electrical insulating layer 301 as the water-repellent layer. Example 2 shows an example of a second water-repellent insulating layer 306 set by replacing the entire electrical insulating layer as the water-repellent layer. However, the water-repellent layer is not limited to the structures shown in Examples 1 and 2. In short, any configuration that has a water-repellent layer made of a water-repellent material on the adsorption surface that adsorbs thin objects is acceptable, for example, a configuration in which the entirety or part of the electrostatic adsorption force generating member is covered with a water-repellent resin film or the like.

[0053] Examples 1 and 2 show preferred examples in which a fluorine material is used as the water-repellent material for the water-repellent layers (first water-repellent insulating layer 305 and second water-repellent insulating layer 306). However, the water-repellent material for the water-repellent layers is not limited to a fluorine material; any material other than a fluorine material may be used as long as it has at least water-repellency. [Explanation of Symbols]

[0054] A1, A2 Electrostatic adsorption tool 10 Thin objects 30 Electrostatic attraction force generating member 305 First water-repellent insulating layer (water-repellent layer) 306 Second water-repellent insulating layer (water-repellent layer) 40 Adsorption force control unit 50 Spin etching equipment (surface processing equipment) U Thin Object Holding Unit

Claims

1. An electrostatic adsorption tool comprising an electrostatic adsorption force generating member that has a group of electrode elements embedded inside an electrical insulating layer and electrostatically adsorbs a thin object by applying a voltage to the group of electrode elements, The electrostatic adsorption force generating member has a water-repellent layer made of a water-repellent material on at least the adsorption surface that adsorbs the thin object, The electrostatic adsorption force generating member is provided with an adsorption force control unit that can be connected to / disconnected from the electrode element group, The adsorption force control unit is a cordless system that connects to the electrostatic adsorption force generating member when adsorbing the thin object, disconnects from the electrostatic adsorption force generating member after adsorbing the thin object, and maintains the generation of electrostatic adsorption force by the charge accumulated in the electrostatic adsorption force generating member. When the electrostatic adsorption tool is introduced into a surface processing apparatus that includes processes in a wet environment, the adsorption force control unit is separated from the electrostatic adsorption force generating member, and the tool is transformed into a unit that can be independently transported while still adsorbing the thin object. The electrostatic adsorption force generating member comprises a base plate and an electrical insulating layer in which a group of electrode elements are embedded. The water-repellent layer is a first water-repellent insulating layer set on the object adsorption side of the electrical insulating layer. An electrostatic adsorption tool characterized by the following features.

2. In the electrostatic adsorption tool described in Claim 1, The aforementioned water-repellent layer uses a fluorine material as the water-repellent material. An electrostatic adsorption tool characterized by the following features.

3. In the electrostatic adsorption tool described in Claim 1 or 2, The thin object in question is a thin plate-like object with a thickness of 0.5 mm or less. An electrostatic adsorption tool characterized by the following features.

4. An electrostatic adsorption tool comprising an electrostatic adsorption force generating member that has a group of electrode elements embedded inside an electrical insulating layer and electrostatically adsorbs a thin object by applying a voltage to the group of electrode elements, The electrostatic adsorption force generating member has a water-repellent layer made of a water-repellent material on at least the adsorption surface that adsorbs the thin object, The electrostatic adsorption force generating member is provided with an adsorption force control unit that can be connected to / disconnected from the electrode element group, The adsorption force control unit is a cordless system that connects to the electrostatic adsorption force generating member when adsorbing the thin object, disconnects from the electrostatic adsorption force generating member after adsorbing the thin object, and maintains the generation of electrostatic adsorption force by the charge accumulated in the electrostatic adsorption force generating member. When the electrostatic adsorption tool is introduced into a surface processing apparatus that includes processes in a wet environment, the adsorption force control unit is separated from the electrostatic adsorption force generating member, and the tool is transformed into a unit that can be independently transported while still adsorbing the thin object. The electrostatic adsorption force generating member comprises a base plate and an electrical insulating layer in which the electrode element group is embedded. The water-repellent layer is a second water-repellent insulating layer, which is formed by replacing the entire electrical insulating layer. An electrostatic adsorption tool characterized by the following features.

5. A method for surface processing an object using an electrostatic adsorption tool as described in any one of Claims 1 to 4, The thin object holding unit, which is composed of the electrostatic attraction force generating member that electrostatically attracts the thin object, is transferred to the surface processing apparatus which includes the wet environment process. The thin object holding unit is set at the internal processing position of the surface processing apparatus and surface processing is performed. Once the surface processing is complete, the thin object holding unit is transferred from the surface processing apparatus to the outside of the apparatus while still holding the surface-processed thin object. A method for surface processing an object, characterized by the following features.

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