JP2022175820A - holding device - Google Patents

Abstract

To provide a holding device capable of preventing immersion of plasma and process gass to the vicinity of an outer peripheral surface of a bonding layer.SOLUTION: A holding device comprises: a plate-like member 10; a base member 20; and a bonding layer 40 that is arranged between the plate-like member 10 and the base member 20, and bonds the plate-like member 10 and the base member 20. An electrostatic chuck 1 that holds a semiconductor wafer W onto a holding surface 11 of the plate-like member 10 has: an inner side protection member 50 arranged so as to cover a whole area of an outer peripheral surface 40a of the bonding layer 40; and an outer side protection member 60 that is arranged at the outer side from the inner side protection member 50 and has a dimension in a Z-axis direction larger than that of the inner side protection member 50. The outer side protection member 60 is arranged so as to cover the whole area of the outer peripheral surface of the inner side protection member 50.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to a holding device for holding an object.

A holding device is known that includes a first member that holds an object on a holding surface, and a second member that is joined to the first member via a joining layer. In this type of holding device, since the bonding layer may deteriorate due to plasma or process gas, measures are taken to protect the outer peripheral surface of the bonding layer. For example, in the wafer support member (holding device) disclosed in Patent Document 1, a recess is formed in the peripheral portion of the adhesive layer (bonding layer), and an annular protection member is arranged in the recess so as to press the wall surface of the recess. Therefore, the protection member prevents plasma and process gas from penetrating into the adhesive layer.

JP-A-2006-80389

However, in the holding device described above, there is a possibility that a gap may occur between the protective member and the bonding layer due to the difference in thermal expansion coefficient between the protective member and the bonding layer. In addition, in order to improve the sealing performance of the protective member, it is necessary to use a highly elastic material for the protective member. Also, there is a possibility that a gap is generated between the protective member and the bonding layer. Furthermore, when the protective member is placed in the recess, the protective member may be twisted or tilted, creating a gap between the protective member and the bonding layer. If a gap is formed between the protective member and the bonding layer, plasma or process gas enters the gap and deteriorates the bonding layer.

Accordingly, the present disclosure has been made to solve the above-described problems, and an object thereof is to provide a holding device capable of preventing plasma and process gas from entering the vicinity of the outer peripheral surface of the bonding layer. do.

One aspect of the present disclosure made to solve the above problems is
a first member having a first surface and a second surface provided opposite to the first surface in a first direction;
a second member comprising a third surface and a fourth surface provided opposite to the third surface in the first direction;
a bonding layer disposed between the second surface of the first member and the third surface of the second member and bonding the first member and the second member;
In a holding device that holds an object on the first surface of the first member,
an inner protective member arranged to cover the entire outer peripheral surface of the bonding layer;
an outer protective member arranged outside the inner protective member and having a dimension in the first direction larger than the inner protective member;
The outer protective member is arranged so as to cover the entire outer peripheral surface of the inner protective member.

In this holding device, the outer protective member, which is larger in the first direction (thickness direction of the holding device) than the inner protective member, is arranged so as to cover the inner protective member. can be prevented from occurring. As a result, the inner protective member can reliably cover the entire outer peripheral surface of the bonding layer. Therefore, the inner protective member and the outer protective member can prevent plasma and process gas from entering the vicinity of the outer peripheral surface of the bonding layer. Even if the inner protective member is displaced, the outer protective member covers the inner protective member, so that the outer protective member prevents plasma and process gas from entering the vicinity of the outer peripheral surface of the bonding layer. be able to.

In the holding device described above,
a first stepped portion for arranging the inner protective member on an outer peripheral portion of the first member on the second surface side and an outer peripheral portion on the third surface side of the second member; a second stepped portion for arranging the outer protective member is formed,
It is preferable that the inner protection member is in contact with both the side surface of the first stepped portion of the first member and the side surface of the first stepped portion of the second member.

In this way, the first stepped portion for arranging the inner protective member and the outer protective member are provided on the outer peripheral portion on the second surface side of the first member and the outer peripheral portion on the third surface side of the second member. By providing the second stepped portion for arranging, the inner protective member and the outer protective member can be arranged at proper positions without being displaced. At this time, since the bonding layer is firmly sealed by the inner protective member, the outer protective member is at least one of the side surface of the first stepped portion of the first member and the side surface of the second stepped portion of the second member. It should be in contact with one side. As a result, the entire inner protective member, which reliably covers the entire outer peripheral surface of the bonding layer, can be reliably covered with the outer protective member. Intrusion of plasma and process gas into the layer can be prevented.

In the holding device described above,
It is preferable that the outer protective member has higher stretchability than the inner protective member.

As a result, the inner protective member can be effectively pressed inward by the outer protective member, so that the sealing performance of the inner protective member that seals the bonding layer can be enhanced. Therefore, it is possible to effectively prevent plasma and process gas from entering the bonding layer.

In the holding device described above,
It is preferable that the outer protective member presses the inner protective member inward in a second direction orthogonal to the first direction.

As a result, the inner protective member can be reliably prevented from being partially twisted or tilted due to the difference in thermal expansion coefficient between the inner protective member and the bonding layer, and the outer protective member can protect the inner side. The member can be pushed inward more effectively. Therefore, the sealing performance of the inner protective member can be further enhanced, and the intrusion of plasma and process gas into the bonding layer can be more effectively prevented.

In the holding device described above,
It is preferable that the outer peripheral surface of the inner protection member is formed in an arc shape that protrudes outward in a second direction orthogonal to the first direction.

As a result, the inner protective member can be more effectively pressed inward by the outer protective member, so that the sealing performance of the inner protective member can be further enhanced. Therefore, it is possible to more effectively prevent plasma and process gas from entering the bonding layer.

According to the present disclosure, it is possible to provide a holding device that can prevent plasma and process gas from entering the vicinity of the outer peripheral surface of the bonding layer.

1 is a schematic perspective view of an electrostatic chuck of an embodiment; FIG. It is a schematic block diagram of the XZ cross section of the electrostatic chuck of the embodiment. It is a schematic block diagram of the XZ cross section which expanded the vicinity of the outer peripheral part of a joining layer. It is a schematic block diagram of the XZ cross section which expanded the vicinity of the outer peripheral part of the joining layer in a modification.

A holding device that is an embodiment according to the present disclosure will be described in detail with reference to the drawings. In this embodiment, for example, an electrostatic chuck used in a semiconductor manufacturing apparatus such as a film forming apparatus (CVD film forming apparatus, sputtering film forming apparatus, etc.) or an etching apparatus (plasma etching apparatus, etc.) is exemplified.

An electrostatic chuck 1 of this embodiment will be described with reference to FIGS. 1 to 3. FIG. The electrostatic chuck 1 of the present embodiment is a device that attracts and holds a semiconductor wafer W (object) by electrostatic attraction. be done. As shown in FIGS. 1 and 2, the electrostatic chuck 1 includes a plate member 10, a base member 20, a bonding layer 40 for bonding the plate member 10 and the base member 20 together, an inner protection member 50 and an outer layer. It has a protection member 60 . The plate member 10 is an example of the "first member" of the present disclosure, and the base member 20 is an example of the "second member" of the present disclosure.

In the following description, the XYZ axes are defined as shown in FIG. 1 for convenience of explanation. Here, the Z-axis is the axis in the axial direction of the electrostatic chuck 1 (vertical direction in FIG. 1), and the X-axis and the Y-axis are the radial axes of the electrostatic chuck 1 . The Z-axis direction is an example of the "first direction" of the present disclosure, and the X-axis direction (Y-axis direction) is an example of the "second direction" of the present disclosure.

As shown in FIG. 1, the plate-like member 10 is a disk-like member made of ceramics. Various ceramics are used as ceramics, but from the viewpoint of strength, wear resistance, plasma resistance, etc., for example, ceramics containing aluminum oxide (alumina, Al ₂ O ₃ ) or aluminum nitride (AlN) as a main component is preferably used. The term "main component" as used herein means a component with the highest content (for example, a component with a volume content of 90 vol % or more).

The plate-like member 10 is composed of an outer peripheral portion 10a, which is a portion having a notch formed on the upper side along the outer periphery, and an inner portion 10b located inside the outer peripheral portion 10a. The thickness of the inner portion 10b of the plate-like member 10 (thickness in the Z-axis direction, the same applies hereinafter) is thicker than the outer peripheral portion 10a by the notch formed in the outer peripheral portion 10a. . That is, the thickness of the plate-like member 10 changes at the position of the boundary between the outer peripheral portion 10a and the inner portion 10b of the plate-like member 10 .

The diameter of the inner portion 10b of the plate-like member 10 is, for example, about 50 mm to 500 mm (usually about 200 mm to 350 mm), and the diameter of the outer peripheral portion 10a of the plate-like member 10 is, for example, about 60 mm to 510 mm (usually 210 mm to 210 mm). 360 mm) (however, the diameter of the outer peripheral portion 10a is larger than the diameter of the inner portion 10b). Further, the thickness of the inner portion 10b of the plate-like member 10 is, for example, about 1 mm to 10 mm, and the thickness of the outer peripheral portion 10a of the plate-like member 10 is, for example, about 0.5 mm to 9.5 mm. The thickness of the outer peripheral portion 10a is thinner than the thickness of the inner portion 10b).

As shown in FIGS. 1 and 2, the plate-like member 10 has a holding surface 11 for holding the semiconductor wafer W, and a holding surface 11 in the thickness direction of the plate-like member 10 (the direction coinciding with the Z-axis direction, the vertical direction). and a lower surface 12 provided on the opposite side. A jig (not shown) for fixing the electrostatic chuck 1, for example, is engaged with the upper surface (peripheral upper surface) of the outer peripheral portion 10a. The holding surface 11 is an example of the "first surface" of the present disclosure, and the lower surface 12 is an example of the "second surface" of the present disclosure.

Inside the plate-like member 10, as shown in FIG. 2, a chuck electrode 13 made of a conductive material (eg, tungsten, molybdenum, platinum, etc.) is arranged. The shape of the chuck electrode 13 as viewed in the Z-axis direction is, for example, a substantially circular shape. When electric power is supplied to the chuck electrode 13 from the outside, an electrostatic attraction is generated, and the semiconductor wafer W is attracted and held on the holding surface 11 of the plate member 10 by this electrostatic attraction.

A heater electrode 14 made of a resistance heating element containing a conductive material (for example, tungsten, molybdenum, platinum, etc.) is arranged inside the plate member 10 . When electric power is supplied to the heater electrode 14 from the outside, the heater electrode 14 generates heat, thereby heating the plate-like member 10 and warming the semiconductor wafer W held on the holding surface 11 of the plate-like member 10 .

3, on the side of the lower surface 12 of the outer peripheral portion of the plate-like member 10, a circumferential first stepped portion 31 in which the inner protective member 50 is arranged, and a A second stepped portion 32 is formed on which the outer protective member 60 is arranged. The first stepped portion 31 has a side surface 31a substantially parallel to the Z-axis direction and a bottom surface 31b substantially orthogonal to the Z-axis direction, and has an L-shaped cross section. Similarly, the second stepped portion 32 has a side surface 32a substantially parallel to the Z-axis direction and a bottom surface 32b substantially orthogonal to the Z-axis direction, and has an L-shaped cross section.

As shown in FIG. 2, the base member 20 is a cylindrical member having the same diameter as the outer peripheral portion 10a of the plate member 10 (or having a larger diameter than the outer peripheral portion 10a). The base member 20 is preferably made of metal (for example, aluminum, aluminum alloy, etc.), but may be made of materials other than metal. The base member 20 includes an upper surface 21 and a lower surface 22 provided on the side opposite to the upper surface 21 with respect to the central axis direction (that is, the Z-axis direction) of the base member 20 (plate-like member 10). Note that the upper surface 21 is an example of the "third surface" of the present disclosure, and the lower surface 22 is an example of the "fourth surface" of the present disclosure.

The diameter of the base member 20 is, for example, approximately 220 mm to 550 mm (usually 220 mm to 350 mm). Also, the thickness of the base member 20 is, for example, about 20 mm to 40 mm.

Further, the base member 20 is formed with a coolant channel 23 for flowing a coolant (for example, fluorine-based inert liquid, water, etc.). The coolant channel 23 is connected to a supply port and a discharge port (not shown) provided on the lower surface 22 of the base member 20 , and the coolant supplied to the base member 20 from the supply port flows into the coolant channel 23 . It flows inside and is discharged to the outside of the base member 20 through the discharge port. In this manner, the base member 20 is cooled by causing the coolant to flow through the coolant passages 23 of the base member 20 , thereby cooling the plate-like member 10 via the joining layer 40 .

As shown in FIG. 3, on the upper surface 21 side of the outer peripheral portion of the base member 20, a circumferential first stepped portion 35 in which the inner protective member 50 is arranged, and a A second stepped portion 36 is formed on which the outer protective member 60 is arranged. The first stepped portion 35 has a side surface 35a substantially parallel to the Z-axis direction and a bottom surface 35b substantially orthogonal to the Z-axis direction, and has an L-shaped cross section. Similarly, the second stepped portion 36 has a side surface 36a substantially parallel to the Z-axis direction and a bottom surface 36b substantially orthogonal to the Z-axis direction, and has an L-shaped cross section.

The joining layer 40 is arranged between the lower surface 12 of the plate member 10 and the upper surface 21 of the base member 20 to join the plate member 10 and the base member 20 together. The bonding layer 40 thermally connects the bottom surface 12 of the plate member 10 and the top surface 21 of the base member 20 . The bonding layer 40 is made of an adhesive such as silicone resin, acrylic resin, or epoxy resin. The thickness (dimension in the Z-axis direction) of the bonding layer 40 is, for example, about 0.1 mm to 1.0 mm. Also, the thermal conductivity of the bonding layer 40 is, for example, 1.0 W/mK. The thermal conductivity of the bonding layer 40 (assuming a silicone resin) is desirably in the range of 0.1 W/mK to 2.0 W/mK (preferably 0.5 W/mK to 1.5 W/mK). .

In this embodiment, the position of the outer peripheral surface 40a of the bonding layer 40 is relative to the position of the side surface 31a of the first stepped portion 31 of the plate member 10 and the position of the side surface 35a of the first stepped portion 35 of the base member 20. , are almost the same, but may recede inward.

The inner protective member 50 and the outer protective member 60 are members for protecting the bonding layer 40 from plasma and process gas. Both ends of the inner protective member 50 are arranged on the first stepped portions 31 and 35 , and both ends of the outer protective member 60 are arranged on the second stepped portions 32 and 36 .

The inner protection member 50 is a substantially annular member when viewed in the Z-axis direction. The inner protective member 50 is made of elastomer (eg, synthetic rubber) or resin (eg, fluororesin). It should be noted that the material forming the inner protective member 50 is preferably a material that has elasticity and is excellent in plasma resistance, heat resistance, and chemical resistance. The material forming the inner protective member 50 is preferably a relatively soft material.

The dimension of the inner protective member 50 in the Z-axis direction (vertical direction in FIG. 3) is substantially equal to the total dimension of the Z-axis direction dimension of the side surface 31a, the thickness of the bonding layer 40, and the Z-axis direction dimension of the side surface 35a. The inner protective member 50 contacts both the side surface 31a and the side surface 35a at both ends in the Z-axis direction, and contacts both the bottom surfaces 31b and 32b at both ends in the Z-axis direction. 31 and 35. Thus, the inner protective member 50 covers the entire outer peripheral surface 40 a of the bonding layer 40 . The Z-axis direction dimension of the inner protection member 50 may be smaller than the total dimension as long as the inner protection member 50 is in contact with the side surface 31a and the side surface 35a at both ends in the Z-axis direction. . The Z-axis direction dimension of the inner protection member 50 is, for example, about 0.3 mm to 6.0 mm, and the width dimension (X-axis or Y-axis direction (horizontal direction in FIG. 3) dimension) is, for example, 0.3 mm to 6.0 mm. It is about 3 mm to 2.0 mm.

Like the inner protection member 50, the outer protection member 60 is also a substantially annular member when viewed in the Z-axis direction. The outer protective member 60 is made of, for example, an elastomer (such as synthetic rubber) or resin (such as fluororesin). The material for forming the outer protective member 60 is preferably a material having elasticity and excellent resistance to plasma, heat, and chemicals. It is preferable that the material has high elasticity. This is because the outer protective member 60 can effectively press the inner protective member 50 inward. In addition, elasticity should just measure an elastic modulus by a dimensional change before and behind a tensile test. Specifically, it is measured based on JIS K 6251:2017, JIS K 7137-2:2001, JIS K 7161-1 2014, and the like. Moreover, it is preferable that the outer protective member 60 has a coefficient of thermal expansion smaller than that of the inner protective member 50 . As a result, even if the inner protection member 50 is partially twisted or tilted due to the difference in thermal expansion coefficient between the inner protection member 50 and the bonding layer 40 (or the outer protection member 60), the outer protection member 60 can be This is because the twist and inclination of the inner protective member 50 can be corrected. In addition, stretchability refers to a property (for example, elasticity) that tends to return to its original shape. The protection member 50 can be effectively pressed inward.

The dimension of the outer protection member 60 in the Z-axis direction (vertical direction in FIG. 3) is larger than the dimension of the inner protection member 50 in the Z-axis direction. While contacting both 32a and side surface 36a, both ends in the Z-axis direction do not contact bottom surface 32b and bottom surface 36b (so that a gap exists between outer protection member 60 and bottom surfaces 32b and 36b), It is located within the second steps 32,36. Thus, the inner protection member 50 is covered with the outer protection member 60 . In this embodiment, the outer protective member 60 contacts both the side surfaces 32a and 36a at both ends in the Z-axis direction, but the outer protective member 60 covers the entire outer peripheral surface of the inner protective member 50. Since it suffices to cover it, it suffices to contact at least one of the side surface 32a and the side surface 36a. Further, the dimension of the outer protection member 60 in the Z-axis direction is, for example, about 0.3 mm to 7.0 mm, and the width dimension (the dimension in the X-axis or Y-axis direction (horizontal direction in FIG. 3)) is, for example, 0.3 mm to 7.0 mm. It is about 3 mm to 2.0 mm.

The outer protective member 60 presses the inner protective member 50 inward (toward the center of the electrostatic chuck 1 as viewed in the Z-axis direction). The pressing of the inner protection member 50 by the outer protection member 60 is, for example, the size (outer diameter) of the outer protection member 60 before installation when viewed in the Z-axis direction, and the size (outer diameter) of the outer protection member 60 after installation (outer diameter). diameter) so that tension is generated in the outer protection member 60 when the outer protection member 60 is installed.

That is, the outer protection member 60 can press the inner protection member 50 if tension is generated in the outer protection member 60 in a state where the outer protection member 60 is installed so as to cover the outer periphery of the inner protection member 50 . Further, even if the width dimension of the inner protective member 50 (dimension in the X-axis or Y-axis direction (horizontal direction in FIG. 3)) is larger than the dimension in the radial direction (X-axis or Y-axis direction) of the bottom surfaces 31b and 35b, , the installed outer protection member 60 can press the inner protection member 50 . In this embodiment, the outer protective member 60, which is larger than the inner protective member 50, has a gap between the outer protective member 60 and the bottom surfaces 32b, 36b. Second step portions 32 and 36 are arranged. Therefore, the deformation of the outer protection member 60 in contact with the bottom surfaces 32b and 36b and shrinking inward is not hindered. Therefore, when the outer protective member 60 is arranged on the second stepped portions 32 and 36, the tension generated in the outer protective member 60 is not reduced, so that the outer protective member 60 firmly presses the inner protective member 50. can be done.

It should be noted that the outer protective member 60 is accommodated within the second stepped portions 32 and 36 when installed so as to cover the outer periphery of the inner protective member 50 . That is, the outer peripheral surface of the outer protection member 60 does not protrude from the outer peripheral surface of the outer peripheral portion 10 a of the plate-shaped member 10 and the outer peripheral surface of the base member 20 . This prevents the outer protective member 60 from interfering with the focus ring when the focus ring is attached to the electrostatic chuck 1 . The focus ring is an annular member used to maintain the plasma density at the peripheral portion of the semiconductor wafer W at the same level as the plasma density at the central portion of the semiconductor wafer W. FIG.

When the electrostatic chuck 1 as described above is used to fix a semiconductor wafer W in a vacuum chamber of a semiconductor manufacturing apparatus, the plasma and process gas used when forming a circuit pattern on the semiconductor wafer W are applied to the bonding layer. 40, the bonding layer 40 corrodes. Therefore, in the electrostatic chuck 1 of the present embodiment, the inner protective member 50 and the outer protective member 60 are provided to prevent the outer peripheral surface 40a of the bonding layer 40 from coming into contact with plasma or process gas.

In this embodiment, the outer protective member 60 having a larger dimension in the Z-axis direction than the inner protective member 50 is arranged on the second stepped portions 32 and 36 so as to cover the inner protective member 50 . Therefore, even if the inner protective member 50 disposed on the first stepped portions 31 and 35 is twisted or tilted, the outer protective member 60 covers the entire outer peripheral surface of the inner protective member 50 from the outside. Twists and tilts are corrected. That is, it is possible to prevent the inner protective member 50 arranged on the first stepped portions 31 and 35 from being twisted or tilted. As a result, the inner protective member 50 can reliably cover the entire outer peripheral surface 40 a of the bonding layer 40 .

Therefore, the inner protective member 50 and the outer protective member 60 can prevent plasma and process gas from entering the vicinity of the outer peripheral surface 40 a of the bonding layer 40 . Even if the inner protective member 50 is displaced from the first stepped portions 31 and 35 without correcting the twist or inclination of the inner protective member 50 completely, the outer protective member 60 does not cover the inner protective member 50 . Therefore, the outer protection member 60 can prevent plasma and process gas from entering the vicinity of the outer peripheral surface 40 a of the bonding layer 40 .

In the electrostatic chuck 1 of the present embodiment, the first stepped portion for arranging the inner protective member 50 is provided on the outer peripheral portion on the lower surface 12 side of the plate member 10 and the outer peripheral portion on the upper surface 21 side of the base member 20 . 31, 35 and second stepped portions 32, 36 for arranging the outer protective member 60 are provided. Therefore, the inner protective member 50 and the outer protective member 60 can be arranged at appropriate positions without being displaced.

That is, both ends of the inner protective member 50 can be arranged on the first stepped portions 31 and 35 in a state in which they are in contact with both the side surface 31a of the first stepped portion 31 and the side surface 35a of the first stepped portion 35. can. As a result, the entire outer peripheral surface 40 a of the bonding layer 40 can be reliably covered with the inner protective member 50 , so that the bonding layer 40 can be reliably sealed with the inner protective member 50 . Further, in this embodiment, both ends of the inner protection member 50 are in contact with both the bottom surface 31b of the first stepped portion 31 and the bottom surface 35b of the first stepped portion 35 . Therefore, the sealing performance of the bonding layer 40 by the inner protective member 50 is enhanced. Furthermore, both ends of the outer protective member 60 can be arranged on the second stepped portions 32 and 36 in a state in which they are in contact with both the side surface 32a of the second stepped portion 32 and the side surface 36a of the second stepped portion 36. can. As a result, the outer protective member 60 can reliably cover the entire inner protective member 50 that completely covers the entire outer peripheral surface 40 a of the bonding layer 40 . Therefore, the bonding layer 40 can also be sealed by the outer protection member 60 . In this manner, in the present embodiment, since the bonding layer 40 can be sealed by both the inner protective member 50 and the outer protective member 60, plasma and process gas near the outer peripheral surface 40a of the bonding layer 40 are intrusion can be reliably prevented.

In addition, since the outer protection member 60 is more stretchable than the inner protection member 50, the outer protection member 60 can effectively press the inner protection member 50 inward. Therefore, it is possible to reliably prevent the inner protective member 50 arranged on the first stepped portions 31 and 35 from being partially twisted or tilted. Therefore, the sealing performance of the bonding layer 40 by the inner protective member 50 can be further enhanced. This makes it possible to more effectively prevent plasma and process gas from entering the vicinity of the outer peripheral surface 40 a of the bonding layer 40 .

Here, a modified example will be described with reference to FIG. In the modified example, as shown in FIG. 4, the basic configuration is the same as the above embodiment, but the shape of the inner protective member 150 is different from that of the above embodiment. That is, in the modified example, the outer peripheral surface 150a of the inner protection member 150 is formed in an arc shape that protrudes outward in the radial direction (X-axis or Y-axis direction).

In such a modification, as in the above-described embodiment, the inner protective member 150 is arranged on the first stepped portions 31 and 35 so as to cover the entire outer peripheral surface 40a of the bonding layer 40, and the outer peripheral surface of the inner protective member 150 is An outer protective member 60 is arranged on the second stepped portions 32 and 36 so as to cover the entire surface 150a. In the modified example, since the outer peripheral surface 150a of the inner protection member 150 has an arcuate shape that protrudes outward, the outer protection member 60 can press the inner protection member 150 inward more effectively. Therefore, since the sealing performance of the bonding layer 40 by the inner protective member 150 can be further enhanced, it is possible to more effectively prevent plasma and process gas from entering the vicinity of the outer peripheral surface 40 a of the bonding layer 40 .

As described above, according to the electrostatic chuck 1 of the present embodiment, the inner protective member 50 is arranged so as to cover the outer peripheral surface 40 a of the bonding layer 40 , and the inner protective member 50 is arranged so as to cover the inner protective member 50 . An outer protective member 60 having a larger dimension in the Z-axis direction than the outer protective member 60 is arranged. Therefore, the inner protective member 50 can be prevented from being twisted or tilted, so that the inner protective member 50 can reliably cover the entire outer peripheral surface 40 a of the bonding layer 40 . Therefore, the inner protective member 50 and the outer protective member 60 can prevent plasma and process gas from entering the vicinity of the outer peripheral surface 40 a of the bonding layer 40 .

Since the inner protective member 50 is arranged on the first stepped portions 31 and 35 provided on the plate member 10 and the base member 20, respectively, and the outer protective member 60 is arranged on the second stepped portions 32 and 36, The inner protection member 50 and the outer protection member 60 can be arranged at proper positions without being displaced. Therefore, since the outer protective member 60 can reliably cover the entire inner protective member 50 in a state in which the entire outer peripheral surface 40a of the bonding layer 40 is reliably covered, the inner protective member 50 reliably seals the bonding layer 40. This can prevent plasma and process gas from entering the bonding layer 40 .

It should be noted that the above-described embodiment is merely an example and does not limit the present disclosure in any way, and of course various improvements and modifications are possible without departing from the gist of the present disclosure. For example, in the above embodiments, the case where the present disclosure is applied to an electrostatic chuck is illustrated, but the present disclosure is not limited to electrostatic chucks, and can be applied to general holding devices that hold an object on a surface. can be done.

1 Electrostatic chuck 10 Plate member 11 Holding surface 12 Lower surface 20 Base member 21 Upper surface 22 Lower surface 31 First stepped portion 32 Second stepped portion 35 First stepped portion 36 Second stepped portion 40 Bonding layer 50 Inner protection member 60 Outer protection Member 150 Inner protection member 150a Outer peripheral surface W Semiconductor wafer

Claims (5)

a first member having a first surface and a second surface provided opposite to the first surface in a first direction;
a second member comprising a third surface and a fourth surface provided opposite to the third surface in the first direction;
a bonding layer disposed between the second surface of the first member and the third surface of the second member and bonding the first member and the second member;
In a holding device that holds an object on the first surface of the first member,
an inner protective member arranged to cover the entire outer peripheral surface of the bonding layer;
an outer protective member arranged outside the inner protective member and having a dimension in the first direction larger than the inner protective member;
The holding device, wherein the outer protective member is arranged so as to cover the entire outer peripheral surface of the inner protective member. A holding device according to claim 1,
a first stepped portion for arranging the inner protective member on an outer peripheral portion of the first member on the second surface side and an outer peripheral portion on the third surface side of the second member; a second stepped portion for arranging the outer protective member is formed,
The holding device, wherein the inner protective member is in contact with both a side surface of the first stepped portion of the first member and a side surface of the first stepped portion of the second member. In the holding device according to claim 1 or claim 2,
The holding device, wherein the outer protective member has higher stretchability than the inner protective member. In any one holding device according to claims 1 to 3,
The holding device, wherein the outer protective member presses the inner protective member inwardly in a second direction orthogonal to the first direction. In any one holding device according to claims 1 to 3,
The holding device, wherein the outer peripheral surface of the inner protective member is formed in an arcuate shape that protrudes outward in a second direction orthogonal to the first direction.

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