JP7312031B2 - ELECTROSTATIC CHUCK AND METHOD OF OPERATION THEREOF - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic chuck for holding a substrate such as a semiconductor wafer using electrostatic attraction force, and a method of operating the same.

2. Description of the Related Art Conventionally, electrostatic chucks have been used to hold substrates (semiconductor wafers, etc.) in semiconductor manufacturing equipment and thin display manufacturing equipment. An electrostatic chuck includes an electrostatic chuck body having a surface for attracting a substrate, and the electrostatic chuck body is constructed by embedding an electrode for electrostatic attraction in a flat ceramic sintered body.

When the electrostatic chuck holds the substrate, the substrate to be attracted is placed on the attraction surface of the electrostatic chuck body, and a voltage is applied to the electrodes embedded in the electrostatic chuck body. As a result, an electrostatic force (attractive force) is generated between the lower surface of the substrate and the attracting surface of the electrostatic chuck body, and the substrate is electrostatically attracted to the electrostatic chuck body.

For example, when an electrostatic chuck is used in a semiconductor manufacturing apparatus, a film formation process (such as CVD) is applied to the processing surface (upper surface) of the semiconductor wafer while the semiconductor wafer is held by the electrostatic chuck due to the electrostatic adsorption force. ), etching, or exposure.

As described above, the electrostatic chuck is configured to hold the substrate using electrostatic force, so it can hold the substrate without using a mechanical holder. For this reason, the upper surface (particularly the periphery) of the substrate held by the electrostatic chuck is not covered by the mechanical holder. can be processed. In addition, the electrostatic chuck is also used to carry out predetermined measurements on the held substrate and to transport the held substrate.

As described above, the electrostatic chuck electrostatically attracts the substrate by generating an electrostatic force between the lower surface of the substrate to be attracted and the attraction surface of the electrostatic chuck main body. between the surfaces of the Therefore, effective force (electrostatic attraction force) is not generated unless the lower surface of the substrate and the attraction surface of the electrostatic chuck body are sufficiently close to or in contact with each other.

Therefore, in order to electrostatically attract the substrate by the electrostatic chuck, the lower surface of the substrate and the attraction surface of the electrostatic chuck body must be in close contact with each other as a whole or slightly separated from each other before attraction. Even if it is, it must be to the extent that it does not hinder the electrostatic adsorption (to the extent that the substrate can be flattened by the electrostatic adsorption force).

However, the substrate to be sucked is not necessarily flat, and it is becoming difficult to ensure sufficient flatness of the substrate, especially as the size of the substrate increases. That is, the substrate is bent or warped. For example, the central portion of the substrate protrudes upward (convex shape), conversely, the central portion protrudes downward (concave shape), or the entire substrate is shaped like a saddle. shape (saddle shape). If the substrate is deformed in this manner, a relatively large gap is generated between the lower surface of the substrate and the attraction surface of the electrostatic chuck main body before it is attracted by the electrostatic chuck. There is a problem that adsorption becomes difficult or impossible.

Japanese Unexamined Patent Application Publication No. 2002-100002 discloses an electrostatic chuck having a concave attraction surface for attracting a substrate. This conventional electrostatic chuck may be able to deal with (adsorb) a concave substrate to some extent, but it cannot deal with (adsorb) a concave substrate or a saddle substrate. However, depending on the degree of deformation, it cannot be dealt with (adsorbed). In addition, in this conventional electrostatic chuck, the attraction surface is formed in a fixed (non-deformable) concave shape, and the substrate attracted by the electrostatic chuck corresponds to the concave shape of the attraction surface of the electrostatic chuck. It has a deformed shape. That is, even if the conventional electrostatic chuck can attract the deformed substrate, it cannot correct the flatness of the deformed substrate.

JP 2018-064055 A

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrostatic chuck capable of reliably electrostatically attracting a deformed substrate and a method of operating the same. Another object of the present invention is to provide an electrostatic chuck capable of flattening a deformed substrate and a method of operating the same.

[1] In order to achieve the above object, an electrostatic chuck according to the present invention comprises:
a curved sheet-shaped electrostatic chuck body;
a base including a flat mounting surface on which the electrostatic chuck body is mounted;
flattening means for flattening the electrostatic chuck body on the mounting surface by applying an external force to the curved sheet-shaped electrostatic chuck body placed on the base. It is characterized by

According to the electrostatic chuck of the present invention having the above characteristics, the substrate is electrostatically attracted by the curved sheet-shaped electrostatic chuck body, so that even if the substrate is deformed, the substrate can be reliably attracted.

Further, after the deformed substrate is electrostatically attracted by the electrostatic chuck body, the electrostatic chuck body is flattened by the flattening means, so that the deformed substrate is integrally flattened with the electrostatic chuck body. be corrected.

As described above, the present invention can achieve two effects, that is, the reliable adsorption of the deformed substrate and the flatness correction of the deformed substrate.

[2] Further, in the electrostatic chuck of the present invention,
The flattening means abuts on the edge portion of the curved sheet-shaped electrostatic chuck main body and presses the edge portion of the electrostatic chuck main body spaced apart from the mounting surface toward the mounting surface. It is preferred to have a movable abutment member.

According to the present invention, the curved sheet-shaped electrostatic chuck body can be mechanically and reliably flattened by the movable contact member. Since the flattening of the electrostatic chuck body is performed mechanically, it functions effectively even in a reduced pressure space, for example.

[3] Further, in the electrostatic chuck of the present invention,
The flattening means applies a vacuum attraction force to the lower surface of the curved sheet-shaped electrostatic chuck main body to attract the portion of the electrostatic chuck main body separated from the mounting surface toward the mounting surface. It is preferable to have a vacuum suction mechanism of

According to the present invention, a curved sheet-shaped electrostatic chuck body can be flattened by a vacuum suction mechanism without using a mechanical mechanism. Since there is no mechanical mechanism, generation of particles due to contact between members can be suppressed.

[4] Further, in the electrostatic chuck of the present invention,
The flattening means generates an electrostatic force between the lower surface of the curved sheet-shaped electrostatic chuck body and the mounting surface, thereby flattening the portion of the electrostatic chuck body spaced apart from the mounting surface. It is preferable to have an electrostatic adsorption mechanism for drawing toward the placement surface.

According to the present invention, a curved sheet-shaped electrostatic chuck body can be flattened by an electrostatic chucking mechanism without using a mechanical mechanism. Since there is no mechanical mechanism, generation of particles due to contact between members can be suppressed. In addition, since the electrostatic adsorption force is used to flatten the electrostatic chuck body, it functions effectively even in a decompressed space, for example.

[5] To achieve the above objects, the present invention provides any of the above electrostatic chuck operating methods, comprising:
a substrate mounting step of mounting the deformed substrate on the curved sheet-shaped electrostatic chuck body mounted on the mounting surface;
flattening the curved sheet-shaped electrostatic chuck body on the mounting surface by the flattening means in a state in which the deformed substrate is electrostatically attracted to the curved sheet-shaped electrostatic chuck body; and a conversion step.

According to the operating method of the electrostatic chuck of the present invention having the above characteristics, the substrate is electrostatically attracted by the curved sheet-shaped electrostatic chuck main body, so that even if the substrate is deformed, the substrate can be reliably attracted. can be done.

Further, after the deformed substrate is electrostatically attracted by the electrostatic chuck body, the electrostatic chuck body is flattened by the flattening means, so that the deformed substrate is integrally flattened with the electrostatic chuck body. be corrected.

As described above, the present invention can achieve two effects, that is, the reliable adsorption of the deformed substrate and the flatness correction of the deformed substrate.

1 is a longitudinal sectional view schematically showing an electrostatic chuck that is an embodiment of the present invention; FIG. (a) is a plan view of the electrostatic chuck shown in FIG. 1, (b) is a partially enlarged view of (a), and (c) is for explaining the operation of a movable contact member. Illustration of . 1. It is a figure for demonstrating the operating method of the electrostatic chuck shown in FIG. 1, (a) shows the state before mounting a deformed substrate on the curved electrostatic chuck main body, (b) shows a curved 2 shows a state in which a deformed substrate is placed on a flattened electrostatic chuck body and electrostatically chucked. 2A is a diagram for explaining a method of operating the electrostatic chuck shown in FIG. 1, in which (a) shows a state in which an electrostatic chuck main body is flattened by a flattening means and the surface of the electrostatically chucked substrate is corrected; (b) shows the retracted state of the movable abutment member constituting the flattening means. FIG. 4 is a diagram for explaining flattening means of an electrostatic chuck, which is a modified example of the embodiment shown in FIG. 1; FIG. 4A is a longitudinal sectional view schematically showing an electrostatic chuck according to another embodiment of the present invention, in which (a) shows a state in which a deformed substrate is placed on a curved electrostatic chuck body and electrostatically attracted; 4B shows a state in which the surface of the electrostatically chucked substrate is corrected by flattening the electrostatic chuck body by the flattening means. FIG. 4A is a longitudinal sectional view schematically showing an electrostatic chuck according to another embodiment of the present invention, in which (a) shows a state in which a deformed substrate is placed on a curved electrostatic chuck body and electrostatically attracted. , and (b) shows a state in which the electrostatic chuck body is flattened by a flattening means and the surface of the electrostatically chucked substrate is corrected. FIG. 8A is a vertical cross-sectional view schematically showing an electrostatic chuck that is a modification of the embodiment shown in FIG. 6 or 7, and FIG. (b) shows a state in which the surface of the electrostatically attracted substrate is corrected by flattening the electrostatic chuck main body by the flattening means.

An electrostatic chuck and an operating method thereof according to embodiments of the present invention will be described below with reference to the drawings. Note that the aspect ratios of the respective members shown in the drawings are changed from actual values for the sake of easy understanding of the contents of the drawings.

1 and 2 show an electrostatic chuck 1 according to one embodiment of the invention. The electrostatic chuck 1 according to this embodiment is particularly suitable for attracting and holding a semiconductor wafer (circular substrate) in a semiconductor manufacturing apparatus.

As shown in FIGS. 1 and 2, the electrostatic chuck 1 according to the present embodiment has a sheet-shaped electrostatic chuck body 2 for electrostatically attracting a substrate, and the upper surface of the electrostatic chuck body 2 is the substrate. form the adsorption surface 2a. The electrostatic chuck body 2 has a curved shape in its natural state, and is curved in a concave shape in this example. A base 3 is arranged below the electrostatic chuck main body 2 , and the electrostatic chuck main body 2 is mounted on a flat mounting surface 3 a formed on the upper surface of the base 3 .

The electrostatic chuck body 2 includes a circular sheet-shaped ceramic sintered body 2b and a bipolar electrode 2c embedded inside the ceramic sintered body 2b. A connection cable 4 is connected to each of the bipolar electrodes 2c from the surface (lower surface) of the ceramic sintered body 2b opposite to the attracting surface 2a. The connection cable 4 is inserted through a through hole 3 b that vertically penetrates the base 3 . A voltage for electrostatic chucking is applied to each electrode 2c of the electrostatic chuck body 2 from an external power supply (not shown) via the connection cable 4 .

The electrostatic chuck 1 further includes a plurality of (four in this example) substantially rod-shaped movable contact members 5 . A horizontally extending hook portion 5 a is provided at the upper end of the movable contact member 5 . Through holes 3c extending in the vertical direction are formed in the peripheral portion of the base 3 at equal angular intervals in the circumferential direction. A movable contact member 5 is inserted through the through hole 3c so as to be movable up and down.

The movable contact member 5 is vertically driven by an elevation drive means (not shown), and rotated about its longitudinal axis by a rotary drive means (not shown). The elevation drive means and the rotation drive means can be configured by combining a drive source such as a piezo element (piezoelectric actuator) or linear motor and a power transmission mechanism such as a gear mechanism.

As described above, the movable contact member 5 is rotatable about its longitudinal axis, and has a position where the hook portion 5a can contact the edge portion of the electrostatic chuck body 2 shown in FIG. The hook portion 5a can be switched to the position shown in FIG. At the retracted position shown in FIG. 2(c), when the movable contact member 5 is moved up and down, the hook portion 5a can move in and out of the through hole 3c.

The movable contact member 5 constitutes flattening means in the present invention, and applies an external force to the curved sheet-shaped electrostatic chuck main body 2 placed on the base 3 to flatten the electrostatic chuck main body 2 . It is configured to be flattened on the mounting surface 3a.

That is, when the movable contact member 5 is lowered by the elevation driving means from the state shown in FIG. The edge portion of the electrostatic chuck main body 2 that is in contact with the mounting surface 3a and separated from the mounting surface 3a is pressed toward the mounting surface 3a. As a result, the edge portion of the electrostatic chuck body 2 that has been floating above the mounting surface 3a is displaced toward the mounting surface 3a, and the electrostatic chuck body 2 is flattened on the mounting surface 3a. The deformation of the electrostatic chuck body 2 at this time is preferably elastic deformation.

When the electrostatic chuck 1 is used in, for example, a semiconductor manufacturing apparatus (such as a film forming apparatus), the material of the ceramic sintered body 2b is halogen-based gas (for example, CF ₄ , SF ₆ , NF ₃ , ClF ₃ ). Those having high corrosion resistance to are preferred. Examples thereof include alumina, aluminum nitride, yttrium oxide, composite oxide of yttrium and aluminum, magnesium oxide, or fluoride.

The material and thickness of the ceramic sintered body 2b forming the electrostatic chuck main body 2 are not particularly limited, but in order to elastically deform the electrostatic chuck main body 2 by applying an external force by the flattening means, the electrostatic chuck It is preferable that the body 2 has a relatively low rigidity. For example, it is preferable to use alumina (Al ₂ O ₃ ) or aluminum nitride as the ceramic sintered body 2b and to set the thickness to 5 mm or less.

As a method for manufacturing the electrostatic chuck main body 2, a sheet lamination method of laminating and molding green sheets on which electrodes are printed is suitable. The laminated body becomes a sintered body by firing, but the desired sintered body can be obtained by using a molding die or applying a load (for example, to the central part) with a weight during firing or in a subsequent heat treatment. can be deformed into a curved shape.

As an example of the electrostatic chuck main body 2, an alumina green sheet (thickness: 0.6 mm) is printed with a tungsten paste to serve as the electrostatic attraction electrode 2c, and a plurality of unprinted green sheets are laminated on this. . At this time, holes for exposing the electrodes are previously formed in the green sheet arranged on one side of the electrodes.

After the laminate is hot-pressed, it is processed to produce a compact. This is fired at 1600° C. or higher in a reducing atmosphere to obtain an alumina sintered body. This is processed so that the total thickness is 1.5 mm, the distance between the electrode 2c and the adsorption surface 2a (insulating layer thickness) is 0.3 mm, and the surface roughness is Ra 0.1 μm.

The flat electrostatic chuck body 2 thus obtained is deformed by heat treatment. That is, a flat electrostatic chuck body whose outer peripheral portion is supported in a ring shape is placed in a reducing atmosphere furnace, a weight is placed on the center portion, and heat treatment is performed at 1500° C. for 1 hour.

After the heat treatment, the electrostatic chuck main body 2 is deformed into a concave shape at its central portion, and has a concave shape as a whole with a depth of deformation of about 200 μm.

As the material of the base 3 on which the electrostatic chuck main body 2 is placed, metal or ceramics is suitable. Also, the material of the movable contact member 5 is preferably metal or ceramics.

Further, by additionally embedding a heating electrode inside the electrostatic chuck main body 2, it is possible to configure an electrostatic chuck having a substrate heating function in addition to the substrate adsorption holding function. Heating of the substrate is performed, for example, when a film is formed on a semiconductor wafer in a semiconductor manufacturing apparatus. 2. Description of the Related Art In order to ensure high in-plane uniformity in a film forming process of a semiconductor wafer, it is necessary to uniformly heat the entire surface of the semiconductor wafer. Therefore, it is important that the entire bottom surface of the substrate is in close contact with the attraction surface 2a of the electrostatic chuck body 2, and the electrostatic chuck 1 according to this embodiment is suitable for such a case.

Next, a method of operating the electrostatic chuck 1 according to this embodiment will be described with reference to FIGS. 3 and 4. FIG.

As shown in FIG. 3(a), the curved sheet-shaped electrostatic chuck main body 2 is mounted on the mounting surface 3a of the base 3, and as shown in FIG. The substrate S deformed into a concave shape is placed on the attraction surface 2a of the electrostatic chuck main body 2 (substrate placement step).

At this time, since the chucking surface 2a of the electrostatic chuck body 2 is deformed into a concave shape, the deformed lower surface of the substrate S, which is similarly deformed into a concave shape, and the chucking surface 2a of the electrostatic chuck body 2 are aligned as a whole. can be sufficiently close or touching as

A voltage is applied to the electrode 2 c of the electrostatic chuck body 2 via the connection cable 4 while the substrate S is placed on the attraction surface 2 a of the electrostatic chuck body 2 . Then, an electrostatic force is generated between the lower surface of the substrate S and the attraction surface 2 a of the electrostatic chuck body 2 , and the substrate S is attracted to the attraction surface 2 a of the electrostatic chuck body 2 . At this time, since the attraction surface 2a having the concave shape of the electrostatic chuck body 2 is sufficiently close to or in contact with the deformed lower surface of the substrate S having the concave shape as a whole, the electrostatic A sufficient electrostatic force is generated over the entire surface between the chuck body 2 and the chucking surface 2a. As a result, even a deformed substrate S can be reliably attracted by the electrostatic chuck main body 2 .

Next, in a state where the deformed substrate S is electrostatically attracted to the curved electrostatic chuck main body 2, as shown in FIG. The peripheral portion of the main body 2 is pressed and displaced toward the mounting surface 3a to flatten the electrostatic chuck main body 2 on the mounting surface 3a (flattening step). As a result, the substrate S electrostatically attracted to the electrostatic chuck body 2 is simultaneously flattened.

Here, since the hook portion 5a of the movable contact member 5 is not in contact with the substrate S, the state shown in FIG. Desired processing (for example, film formation processing, etching processing, or exposure processing) can be performed on the substrate S while it is in contact with the portion.

On the other hand, the hook portion 5a of the movable contact member 5 is switched from the contact position shown in FIG. 2B to the retracted position shown in FIG. The movable contact member 5 can also be retracted as shown in 4(b).

In this case, a means for maintaining the flat state of the electrostatic chuck body 2 is required even after the external force by the movable contact member 5 is released. A vacuum chucking mechanism for vacuum chucking or an electrostatic chucking mechanism for electrostatic chucking can be provided with respect to 3a.

As described above, according to the electrostatic chuck 1 of the present embodiment, the substrate S is electrostatically attracted by the curved sheet-shaped electrostatic chuck main body 2, so that even if the substrate S is deformed, the can be adsorbed.

Further, when the electrostatic chuck 1 serves both as holding means and heating means for the substrate S, the entire lower surface of the substrate S is firmly attracted to the attraction surface 2a of the electrostatic chuck main body 2, so that the substrate S is held. can be heated with high in-plane uniformity. As a result, high in-plane uniformity can be ensured in, for example, semiconductor wafer processing (film formation processing, etc.).

Further, after the deformed substrate S is electrostatically attracted by the electrostatic chuck body 2 , the electrostatic chuck body 2 is flattened by the movable abutment member 5 . They are flattened together and flattened.

For example, when exposure processing is performed on a semiconductor wafer in a semiconductor manufacturing apparatus, a high degree of flatness is required for the processing surface (upper surface) of the semiconductor wafer. Even so, the electrostatic chuck 1 of the present embodiment corrects the flatness of the deformed semiconductor wafer, thereby meeting the demand for high flatness required for exposure processing.

As described above, the electrostatic chuck 1 according to the present embodiment can achieve two effects, that is, reliable adsorption of the deformed substrate S and flatness correction of the deformed substrate S. FIG.

Further, according to the electrostatic chuck 1 according to the present embodiment, the curved sheet-shaped electrostatic chuck main body 2 can be mechanically and reliably flattened by the movable contact member 5 . Since the flatness of the electrostatic chuck main body 2 is mechanically corrected, it functions effectively even in a decompressed space, for example.

As a modified example of the above-described embodiment, instead of the substantially rod-shaped movable contact member 5, as shown in FIG. good. That is, in this example, a plurality of (for example, four) screw members 6 are provided on the base 3 so as to be rotatable about their longitudinal axes. The end of the peripheral portion of the electrostatic chuck main body 2 is fitted into the screw groove of the screw member 6 .

Then, when the screw member 6 rotates around its longitudinal axis, the end of the peripheral edge of the electrostatic chuck body 2 that is fitted in the screw groove of the screw member 6 is displaced downward or upward. When flattening the electrostatic chuck body 2 curved in a concave shape, the screw member 6 is rotated around its longitudinal axis to displace the end of the peripheral edge of the electrostatic chuck body 2 downward. . As a result, the electrostatic chuck main body 2 is flattened on the mounting surface 3 a of the base 3 .

Also in this modified example, the same effect as the embodiment described above can be obtained.

Next, an electrostatic chuck 1A according to another embodiment of the invention will be described with reference to FIG.

The electrostatic chuck 1A according to the present embodiment is the same as the electrostatic chuck 1 according to the above-described embodiment, except that the configuration of the flattening means is changed.

That is, in the electrostatic chuck 1A according to the present embodiment, a vacuum exhaust line 10 is formed inside the base 3 as shown in FIG. The evacuation line 10 has a plurality of suction ports 10a that open at the mounting surface 3a of the base 3. As shown in FIG. The vacuum exhaust line 10 is connected to a vacuum source (not shown), and the vacuum exhaust line 10 constitutes a vacuum suction mechanism as flattening means in the present invention.

As shown in FIG. 6A, in a state in which the deformed substrate S is electrostatically attracted by the curved sheet-shaped electrostatic chuck main body 2, a vacuum exhaust line 10 is provided on the lower surface of the electrostatic chuck main body 2 to vacuum-adhere. give power. As a result, the portion of the electrostatic chuck body 2 separated from the mounting surface 3a is attracted toward the mounting surface 3a by the vacuum attraction force. As a result, as shown in FIG. 2 is flattened and, at the same time, the deformed substrate S is flattened.

According to the electrostatic chuck 1A according to the present embodiment, similarly to the electrostatic chuck 1 according to the above-described embodiments, the deformed substrate S can be reliably electrostatically attracted, and the surface of the electrostatically attracted substrate S can be corrected. can.

Further, according to the electrostatic chuck 1A according to the present embodiment, the curved sheet-shaped electrostatic chuck main body 2 can be flattened by the vacuum suction mechanism 10 without using a mechanical mechanism. Since there is no mechanical mechanism, generation of particles due to contact between members can be suppressed.

Next, an electrostatic chuck 1B according to another embodiment of the invention will be described with reference to FIG.

The electrostatic chuck 1B according to the present embodiment is the same as the electrostatic chuck 1 according to the above-described embodiment, except that the flattening means has a different configuration.

That is, in the electrostatic chuck 1</b>B according to the present embodiment, an additional electrode 20 is provided inside the electrostatic chuck body 2 in addition to the electrode 2 c for electrostatically attracting the substrate S. The additional electrode 20 constitutes an electrostatic adsorption mechanism in the present invention, and generates an electrostatic force between the lower surface of the curved sheet-shaped electrostatic chuck main body 2 and the mounting surface 3a of the base 3. , the portion of the electrostatic chuck body 2 spaced apart from the mounting surface 3a is drawn toward the mounting surface 3a by electrostatic force.

As shown in FIG. 7A, when the deformed substrate S is electrostatically attracted by the curved sheet-shaped electrostatic chuck main body 2, the lower surface of the electrostatic chuck main body 2 and the mounting surface 3a of the base 3 are aligned. , an additional electrode 20 generates an electrostatic adsorption force. As a result, the portion of the electrostatic chuck main body 2 separated from the mounting surface 3a is attracted toward the mounting surface 3a by the electrostatic adsorption force. As a result, as shown in FIG. The main body 2 is flattened and, at the same time, the deformed substrate S is flattened.

According to the electrostatic chuck 1B of the present embodiment, similarly to the electrostatic chuck 1 of the above embodiment, the deformed substrate S can be reliably electrostatically attracted, and the surface of the electrostatically attracted substrate S can be corrected. can.

Further, according to the electrostatic chuck 1B of the present embodiment, the curved sheet-shaped electrostatic chuck main body 2 is flattened by the additional electrode 20 constituting the electrostatic adsorption mechanism without using a mechanical mechanism. be able to. Since there is no mechanical mechanism, generation of particles due to contact between members can be suppressed. In addition, since the electrostatic chucking force is used to flatten the electrostatic chuck main body 2, it functions effectively even in a decompressed space, for example.

Next, as a modified example of the embodiment provided with the vacuum suction mechanism shown in FIG. 6 or the embodiment provided with the electrostatic attraction mechanism shown in FIG. 7, the electrostatic chuck body shown in FIG. The curved shape of 2 may be a convex shape instead of a concave shape. In addition, in FIG. 8, illustration of a vacuum suction mechanism or an electrostatic attraction mechanism is omitted.

Even when the electrostatic chuck main body 2 has a central convex shape, the shape of the electrostatic chuck main body 2 can be changed by the vacuum suction force of the vacuum suction mechanism or the electrostatic attraction force of the electrostatic attraction mechanism as shown in FIG. can be changed from the curved state shown in FIG. 8B to the flat state shown in FIG.

According to this modified example, it is possible to reliably electrostatically attract the substrate S that has been deformed into a central convex shape, and to correct the surface thereof.

As another modification, any two or all three of the mechanical flattening means, the vacuum suction flattening means, and the electrostatic attraction flattening means may be combined into one. It may be incorporated into one electrostatic chuck.

1, 1A, 1B Electrostatic chuck 2 Electrostatic chuck main body 2a Adsorption surface 2b of electrostatic chuck main body Ceramic sintered body 2c of electrostatic chuck main body Electrode 3 of electrostatic chuck main body Base 3a Base mounting surface 3b Connection Through-hole 3c in base for cable Through-hole 4 in base for movable abutment member Connection cable 5 Movable abutment member (flattening means)
5a Hook portion 6 of movable contact member Screw member (flattening means)
10 vacuum exhaust line 10a vacuum exhaust line suction port 20 additional electrode S substrate

Claims (5)

a sheet-shaped electrostatic chuck body curved concavely toward the base;
a base including a flat mounting surface on which the electrostatic chuck body is mounted;
flattening means for flattening the electrostatic chuck body on the mounting surface by applying an external force to the curved sheet-shaped electrostatic chuck body placed on the base. An electrostatic chuck characterized by: The flattening means abuts on the edge portion of the curved sheet-shaped electrostatic chuck main body and presses the edge portion of the electrostatic chuck main body spaced apart from the mounting surface toward the mounting surface. 2. The electrostatic chuck of claim 1, further comprising a movable abutment member. The flattening means applies a vacuum attraction force to the lower surface of the curved sheet-shaped electrostatic chuck main body to attract the portion of the electrostatic chuck main body separated from the mounting surface toward the mounting surface. 3. The electrostatic chuck according to claim 1, further comprising a vacuum suction mechanism of . The flattening means generates an electrostatic force between the lower surface of the curved sheet-shaped electrostatic chuck body and the mounting surface, thereby flattening the portion of the electrostatic chuck body spaced apart from the mounting surface. 4. The electrostatic chuck according to any one of claims 1 to 3, further comprising an electrostatic chucking mechanism for attracting the chuck toward the placement surface. A method for operating an electrostatic chuck according to any one of claims 1 to 4,
a substrate mounting step of mounting the deformed substrate on the curved sheet-shaped electrostatic chuck body mounted on the mounting surface;
flattening the curved sheet-shaped electrostatic chuck body on the mounting surface by the flattening means in a state in which the deformed substrate is electrostatically attracted to the curved sheet-shaped electrostatic chuck body; A method of operating an electrostatic chuck, comprising:

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