JP2023046804A - holding device - Google Patents

Abstract

To provide a holding device capable of improving thermal uniformity on a holding surface around a penetration hole.SOLUTION: In an electrostatic chuck 1, a first penetration hole 15 penetrating a holding surface 11 and a bottom face 12 is formed in a tabular member 10, and a second penetration hole 25 penetrating a top face 21 and a bottom face 22 and communicating to the first penetration hole 15 is formed in a base member 20. A third penetration hole 45 communicating to the first penetration hole 15 and the second penetration hole 25 is formed in a joint layer 40. A holding device includes an annular seal member 50 disposed between the bottom face 12 and the top face 21 in such a manner that a central axis CL of the third penetration hole 45 is positioned inside off its own inner periphery in a view in a lamination direction of the tabular member 10 and the base member 20. An annular recess 13 in which the seal member 50 is disposed is formed on the bottom face 12, and both corners 13a of the annular recess 13 are formed in an arcuate shape in which a width dimension of the annular recess 13 becomes larger in a direction from a bottom to an opening of the annular recess 13.SELECTED DRAWING: Figure 4

Description

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

As a holding device, for example, in Patent Document 1, an electrostatic chuck portion (first member), a base portion (second member), and an adhesive layer (bonding layer) that adheres and integrates the electrostatic chuck portion and the base portion ), and a through hole penetrating through them in the thickness direction is disclosed. When such an electrostatic chuck device is used, plasma may enter the through-holes and erode the adhesive layer. A groove (recess) for placement is provided.

JP 2017-162899 A

However, in the holding device as described above, the heat transfer between the first member and the second member deteriorates at the sealing portion provided with the sealing member and the recess. As a result, the temperature difference between the periphery of the through hole and other portions on the holding surface (first surface) increases, and the uniformity of heat on the holding surface deteriorates.

Accordingly, the present disclosure has been made to solve the above-described problems, and an object of the present disclosure is to provide a holding device capable of improving the uniformity of heat on the holding surface around the through hole.

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, a third surface, and a fourth member provided opposite to the third surface and a second member disposed between the second surface of the first member and the third surface of the second member to join the first member and the second member and a bonding layer that holds an object on the first surface of the first member,
The first member is formed with a first through hole penetrating the first surface and the second surface,
The second member is formed with a second through hole that penetrates the third surface and the fourth surface and communicates with the first through hole,
a third through-hole communicating with the first through-hole and the second through-hole is formed in the bonding layer,
When viewed from the lamination direction of the first member and the second member, the second surface and the third surface are arranged such that the center axis of the third through hole is located inside the inner circumference thereof. having an annular sealing member disposed between the surface of
An annular recess in which the seal member is arranged is formed on the second surface,
Both corners of the recess are shaped such that the width dimension of the recess increases from the bottom of the recess toward the opening side of the recess.

In this holding device, both corners of the annular recess in which the seal member is arranged have a shape in which the width dimension of the recess increases from the bottom of the recess toward the opening. Therefore, the volume of the first member (the volume in the vertical direction, that is, the stacking direction of the first member and the second member) increases at both corners of the recess. Therefore, the heat conduction in the stacking direction is averaged in the vicinity of the concave portion, that is, the heat conduction is improved. As a result, the temperature distribution change (temperature gradient) on the first surface (holding surface) can be moderated in the sealing portion around the through hole, and the uniformity of heat on the first surface (holding surface) can be improved. be able to.

In addition, when the corners include an arc (R) shape or a tapered shape, stress concentration that tends to occur at both corners of the concave portion is alleviated. Therefore, since damage to the first member can be prevented, it is possible to improve the reliability and extend the life of the holding device.

In the holding device described above,
It is preferable that the width dimension of the recess is the smallest at the opening, and that the minimum dimension is smaller than the width dimension of the seal member.

By forming the recess in such a shape, the volume of the first member (the volume in the vertical direction, ie, the direction in which the first member and the second member are laminated) in the vicinity of the seal member is further increased. Therefore, the heat conduction in the stacking direction is more evenly distributed (that is, the heat conduction is further improved) in the vicinity of the concave portion, so that the uniformity of heat on the first surface can be further improved.

In addition, since the seal member can be fixed at the opening of the recess, it is possible to suppress the unevenness of the seal member within the recess. Therefore, the sealing member that deteriorates the heat conduction between the first member and the second member always exists at the same position. This eliminates the change in temperature distribution on the first surface due to the bias of the seal member. Therefore, the temperature controllability on the first surface is improved, and the temperature uniformity can be stabilized.

Furthermore, since the seal member is fixed at the opening of the recess, it is possible to suppress the reaction force from the seal member during thermal expansion. Therefore, it is possible to prevent the occurrence of poor bonding between the first member and the second member due to breakage of the bonding layer.

Further, in the holding device described above,
The first member and the second member may be ceramic members.

By doing so, the difference in thermal expansion between the first member and the second member is smaller than when the first member and the second member are made of different materials, so the stress acting on the sealing member is smaller. Therefore, deterioration of the sealing member can be prevented, and corrosion resistance of the bonding layer can be improved. Moreover, since the stress acting on the seal member is reduced, the reaction force from the seal member that the first member receives can be suppressed. Therefore, stress concentration that tends to occur at both corners of the recess can be alleviated. Therefore, since damage to the first member can be effectively prevented, the reliability and durability of the holding device can be further improved.

ADVANTAGE OF THE INVENTION According to this indication, the holding|maintenance apparatus which can improve the uniformity of heat in the holding|maintenance surface around a through-hole can be provided.

1 is a schematic perspective view of an electrostatic chuck of a first embodiment; FIG. 2 is a schematic configuration diagram of an XZ cross section of the electrostatic chuck of the first embodiment; FIG. 2 is a schematic configuration diagram of the XY plane of the electrostatic chuck of the first embodiment; FIG. 4 is a schematic configuration diagram of an XZ cross section near a through hole in the electrostatic chuck of the first embodiment; FIG. 5 is an enlarged view of the annular recess shown in FIG. 4; FIG. FIG. 11 is a schematic configuration diagram of an XZ cross section near a through hole in the electrostatic chuck of the second embodiment; FIG. 11 is a schematic configuration diagram of an XZ cross section near a through-hole in an electrostatic chuck of a third embodiment;

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, an electrostatic chuck that holds a semiconductor wafer, which is an object, will be described as an example.

[First embodiment]
First, the electrostatic chuck 1 of the first embodiment will be described with reference to FIGS. 1 to 4. 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 FIG. 1 , the electrostatic chuck 1 has a plate-like member 10 , a base member 20 , and a joining layer 40 that joins the plate-like member 10 and the base member 20 . In addition, in the present embodiment, 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 . Note that, in the present embodiment, the Z-axis direction is an example of the “stacking 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 member 10 has a diameter of approximately 150 mm to 350 mm and a thickness of approximately 2 mm to 6 mm, for example.

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. Cylindrical first through holes 15a and 15b are formed between the holding surface 11 and the lower surface 12 so as to penetrate in the thickness direction (Z-axis direction, vertical direction in FIG. 2). Note that 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.

A holding surface 11 of the plate member 10 has an uneven shape. Specifically, as shown in FIGS. 2 and 3, the holding surface 11 is formed with an annular projection 16 (so-called seal band) near its outer edge, and a plurality of independent seals are formed inside the annular projection 16 . A columnar protrusion 17 is formed. The shape of the cross section (XZ cross section) of the annular projection 16 is substantially rectangular as shown in FIG. The height (dimension in the Z-axis direction) of the annular projection 16 is, for example, about 10 μm to 20 μm. Further, the width (dimension in the X-axis direction) of the annular projection 16 is, for example, about 0.5 mm to 5.0 mm.

As shown in FIG. 3, each convex portion 17 has a substantially circular shape when viewed in the Z-axis direction (planar view), and is arranged at substantially equal intervals. Moreover, the shape of the cross section (XZ cross section) of each convex portion 17 is substantially rectangular as shown in FIG. The height of the convex portion 17 is substantially the same as the height of the annular convex portion 16, and is, for example, about 10 μm to 20 μm. Further, the width of the convex portion 17 (maximum diameter of the convex portion 17 when viewed in the Z-axis direction) is, for example, about 0.5 mm to 1.5 mm. A portion of the holding surface 11 of the plate-like member 10 inside the annular convex portion 16 where the convex portion 17 is not formed serves as a concave portion 18 .

The semiconductor wafer W is supported by the annular protrusion 16 and the plurality of protrusions 17 on the holding surface 11 of the plate member 10 and held by the electrostatic chuck 1 . When the semiconductor wafer W is held by the electrostatic chuck 1, between the surface (lower surface) of the semiconductor wafer W and the holding surface 11 of the plate member 10 (more specifically, the recess 18 of the holding surface 11), There will be a space S (see FIG. 2). An inert gas (for example, helium gas) is supplied to the space S through gas holes 30b, which will be described later.

The plate member 10 has cylindrical first through holes 15a and 15b (hereinafter referred to as " ) are formed. Around the first through holes 15a and 15b of the lower surface 12, as shown in FIGS. 2 and 4, an annular recess 13 is formed for disposing an annular seal member 50, which will be described later.

As shown in FIG. 4, both corners 13a of the annular recess 13 are shaped such that the width dimension of the annular recess 13 increases from the bottom of the annular recess 13 toward the opening. In this embodiment, both corners 13a are processed into, for example, an arc (R) shape, and the size of the arc (radius R) is about R=0.05 mm to 5.0 mm, more preferably R= 0.1 mm to 0.5 mm. The width dimension of the annular recess 13 is the dimension in the X-axis direction in the ZX cross section of the annular recess 13 .

As shown in FIG. 1, the base member 20 has a cylindrical shape, more specifically, two cylinders having different diameters, and a cylindrical upper surface portion having a large diameter and a cylindrical lower surface portion having a small diameter placed thereon. , and a stepped cylindrical shape formed by stacking them with a common central axis Ca (see FIG. 2). The base member 20 is preferably made of metal (for example, aluminum, aluminum alloy, etc.), but may be made of materials other than metal.

As shown in FIGS. 1 and 2, the base member 20 has an upper surface 21 and a central axis Ca (see FIG. 2) of the base member 20 (plate-like member 10) (that is, the Z-axis direction). and a lower surface 22 provided on the opposite side. 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, about 150 mm to 300 mm at the upper portion and about 180 mm to 350 mm at the lower portion. Also, the thickness (dimension in the Z-axis direction) of the base member 20 is, for example, about 20 mm to 50 mm.

Further, as shown in FIG. 2, 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 bonding layer 40 .

In the base member 20, cylindrical second through holes 25a and 25b (hereinafter referred to as "second through ) are formed. The second through-holes 25a and 25b are coaxial with the first through-holes 15a and 15b (the central axis CL is coincident), and the diameter of the second through-holes 25a and 25b is equal to the diameter of the first through-holes 15a and 15b. is almost the same as

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, approximately 0.1 to 1.0 mm.

As shown in FIG. 2, the bonding layer 40 includes third through holes 45a and 45b (hereinafter referred to as "third through holes 45") for communicating the first through holes 15a and 15b with the second through holes 25a and 25b. ) is formed. That is, cylindrical third through holes 45a and 45b are formed between the first through holes 15a and 15b and the second through holes 25a and 25b. The third through-holes 45a, 45b are coaxial with the first through-holes 15a, 15b and the second through-holes 25a, 25b (with the central axis CL coinciding). The diameters of the third through holes 45a, 45b are larger than those of the first through holes 15a, 15b and the second through holes 25a, 25b. The first through holes 15a and 15b, the third through holes 45a and 45b, and the second through holes 25a and 25b are arranged in a row in the Z-axis direction (the axial direction of the electrostatic chuck 1).

As shown in FIG. 2, the first through hole 15a, the third through hole 45a, and the second through hole 25a form a lift pin insertion hole 30a penetrating the electrostatic chuck 1 in the Z-axis direction. Lift pins 60 that push up the semiconductor wafer W from the holding surface 11 are inserted into the lift pin insertion holes 30 a from the lower surface 22 side of the base member 20 . The lift pin 60 has a cylindrical shape (round bar shape) and moves in the Z-axis direction within the lift pin insertion hole 30a. The lift pins 60 move to one side (upper side in FIG. 2) in the Z-axis direction, and the tips (upper ends) of the lift pins 60 protrude from the holding surface 11 of the plate-shaped member 10 to the outside. The semiconductor wafer W placed on the top is separated from the holding surface 11 (the semiconductor wafer W is lifted by the lift pins 60).

In the electrostatic chuck 1 of the present embodiment, three lift pin insertion holes 30a are formed, and a lift pin 60 is inserted into each of the lift pin insertion holes 30a. The three lift pin insertion holes 30a are formed at equal intervals in the circumferential direction of the electrostatic chuck 1 (see FIG. 3).

A gas hole 30b passing through the electrostatic chuck 1 in the Z-axis direction is formed by the first through-hole 15b, the third through-hole 45b, and the second through-hole 25b. This gas hole 30b is a gas flow path through which an inert gas (for example, helium gas) flows. As a result, by supplying an inert gas (for example, helium gas) from the lower surface 22 side of the base member 20 into the gas holes 30b, the lower surface of the semiconductor wafer W and the holding surface 11 (recess 18) of the plate member 10 are separated. This inert gas can be filled in the space S between. In the following description, the lift pin insertion holes 30a and the gas holes 30b may be simply referred to as "through holes 30".

In the electrostatic chuck 1 as described above, the third through holes 45 (through holes of the bonding layer 40) are sandwiched between the plate-like member 10 and the base member 20, and are arranged in the Z-axis direction to form the first chucks. An annular sealing member 50 is arranged so as to surround the through hole 15 and the second through hole 25, in other words, the third through hole 45 is positioned inside the inner periphery thereof (FIGS. 2 and 4). 4). This sealing member 50 is for protecting the bonding layer 40 and preventing corrosion of the bonding layer 40 .

That is, when the electrostatic chuck 1 is used to fix a semiconductor wafer W in a vacuum chamber of a semiconductor manufacturing apparatus, the processing gas, plasma, and the like used when forming a circuit pattern on the semiconductor wafer W are first penetrated. It flows into the electrostatic chuck 1 through the hole 15 . The sealing member 50 is provided because the bonding layer 40 will be corroded if the plasma or the like penetrates into and contacts the bonding layer 40 . The seal member 50 has an annular or tubular shape and is made of an elastic material such as an arbitrarily selected material such as rubber or elastomer resin.

By providing such a seal member 50, the space between the lower surface 12 of the plate member 10 and the upper surface 21 of the base member 20 is airtightly sealed. As a result, the seal member 50 can prevent plasma or the like that has flowed into the electrostatic chuck 1 through the first through-hole 15 from entering the bonding layer 40 through the third through-hole 45 and coming into contact with the bonding layer 40 . It has become.

However, the heat transfer between the plate-like member 10 and the base member 20 deteriorates at the sealing portion where the sealing member 50 and the annular concave portion 13 are provided. As a result, the temperature difference between the periphery of the through-hole 30 and other portions of the holding surface 11 becomes large, and the temperature uniformity of the holding surface 11 deteriorates around the through-hole 30 .

Therefore, in the electrostatic chuck 1 of the present embodiment, as shown in FIG. 4, both corners 13a of the annular recessed portion 13 are formed into arcs (shapes) in which the width dimension of the annular recessed portion 13 increases from the bottom of the annular recessed portion 13 toward the opening. R) shape. Further, as shown in FIG. 5, the annular recessed portion 13 is composed of both corner portions 13a, a bottom portion 13b and a side wall portion 13c. formed inside the Therefore, compared to when the extension line of the bottom portion 13b and the extension line of the side wall portion 13c intersect (when no corner portion is provided), the width dimension of the annular recess portion 13 increases from the bottom of the annular recess portion 13 toward the opening. The volume (the volume in the Z-axis direction) of the plate member 10 at both corners 13a of the annular recess 13 increases when the portions 13a are formed. That is, the volume of the plate-like member 10 increases in the hatched portion shown in FIG. As a result, in the plate member 10, the heat conduction in the Z-axis direction near the annular concave portion 13 is averaged, that is, the heat conduction is improved. Therefore, in the sealing portion around the through-hole 30, the change in temperature distribution (temperature gradient) on the holding surface 11 can be moderated, and the uniformity of heat on the holding surface 11 can be improved. Since the annular recessed portion 13 has corners 13a on both sides as well as on one side, the volume of the plate member 10 (the volume in the Z-axis direction) can be increased more easily.

In addition, since both corners 13a of the annular recess 13 are arc-shaped, stress concentration that tends to occur at both corners 13a of the annular recess 13 can be alleviated. Therefore, damage to the plate member 10 can be prevented, and as a result, the reliability of the electrostatic chuck 1 can be improved and the life of the electrostatic chuck 1 can be extended.

As described above, according to the electrostatic chuck 1 of the present embodiment, both corners 13a of the annular recessed portion 13 in which the seal member 50 is arranged have an arc (R) shape. The heat conduction in the portion 13a is averaged and the heat conduction is improved. Therefore, in the sealing portion around the through-hole 30, the change in temperature distribution (temperature gradient) on the holding surface 11 can be moderated, and the uniformity of heat on the holding surface 11 can be improved.

[Second embodiment]
Next, a second embodiment will be described. The second embodiment has the same basic structure as the first embodiment, but differs from the first embodiment in the shape of the annular recess in which the sealing member is arranged. That is, in the second embodiment, the cross-sectional shape of the annular recess is such that the width dimension is the smallest at the opening (see FIG. 6). Therefore, the same reference numerals are given to the same configurations as in the first embodiment, and the description thereof is omitted as appropriate, and the description will focus on the differences from the first embodiment.

In the electrostatic chuck 1a of the present embodiment, as shown in FIG. 6, the annular concave portion 73 has the smallest width at the opening, and the smallest dimension is smaller than the width of the seal member 50. ing. In this embodiment, the annular concave portion 73 has, for example, a so-called dovetail shape.

Therefore, in the electrostatic chuck 1a, the volume of the plate member 10 (the volume in the Z-axis direction) in the vicinity of the seal member 50 is further increased. As a result, the heat conduction in the vicinity of the annular concave portion 73 is more evenly distributed, and the heat conduction is further improved.

Moreover, since the seal member 50 can be fixed at the opening of the annular recess 73 , the bias of the seal member 50 within the annular recess 73 can be suppressed. In other words, the seal member 50 can always be arranged at the same position in the annular recess 73 . Therefore, the seal member 50 that deteriorates heat conduction between the plate member 10 and the base member 20 always exists at the same position. This eliminates a change in the temperature distribution on the holding surface 11 due to the unevenness of the seal member 50, thereby improving the temperature controllability on the holding surface 11 and stabilizing the temperature uniformity. Since the annular recess 13 has corners 13a on both sides as well as on one side, the volume of the plate-like member 10 (the volume in the Z-axis direction) can be easily increased, and the seal This is advantageous in suppressing bias of the member 50 .

Furthermore, since the seal member 50 is fixed at the opening of the annular recess 73, the reaction force from the seal member 50 can be suppressed during thermal expansion. Therefore, stress concentration that tends to occur at both corners 73a of the annular recess 73 can be further alleviated, and damage to the plate-like member 10 can be prevented. Life can be extended. In addition, it is possible to prevent the bonding failure between the plate member 10 and the base member 20 due to the breakage of the bonding layer 40 .

[Third Embodiment]
Finally, a third embodiment will be described. The third embodiment has the same basic structure as the first embodiment, but differs from the first embodiment in the configuration of the plate member. Therefore, the same reference numerals are given to the same configurations as in the first embodiment, and the description thereof will be omitted as appropriate, and the description will focus on the points of difference from the above-described embodiment.

In the electrostatic chuck 1b of the third embodiment, as shown in FIG. 7, the plate member 100 includes a first ceramic member 110, a second ceramic member 120, and a and a bonding layer 140 that bonds the . The first ceramic member 110 is an example of the "first member" of the present disclosure, and the second ceramic member 120 is an example of the "second member" of the present disclosure.

The electrostatic chuck 1b also includes a base member 20 similar to that of the first embodiment, and a joining layer 40 that joins the plate member 100 (second ceramics member 120). Furthermore, the electrostatic chuck 1b is sandwiched between the lower surface 122 of the second ceramics member 120 and the upper surface 21 of the base member 20 in the third through hole 45 in the same manner as in the first embodiment. of sealing members 50 are arranged. The sealing member 50 is arranged in an annular recess 123 formed in the lower surface 122 of the plate member 100 (second ceramics member 120), as in the first embodiment. The annular recess 123 has the same shape as the annular recess 13 of the first embodiment.

Here, the first ceramic member 110 forming the plate member 100 is formed with a cylindrical first through hole 115 penetrating between the holding surface 111 and the lower surface 112 in the Z-axis direction. The holding surface 111 is an example of the "first surface" of the present disclosure, and the lower surface 112 is an example of the "second surface" of the present disclosure. A cylindrical second through hole 125 is formed in the second ceramic member 120 so as to penetrate between the upper surface 121 and the lower surface 122 in the Z-axis direction. The upper surface 121 is an example of the "third surface" of the present disclosure, and the lower surface 122 is an example of the "fourth surface" of the present disclosure. The second through-hole 125 is coaxial with the first through-hole 115 (the central axis CL is coincident) and has the same inner diameter. The first through-hole 115, the third through-hole 145, and the second through-hole 125 are arranged in series in the Z-axis direction to form part of the through-hole 30 passing through the electrostatic chuck 1b in the Z-axis direction. are doing.

An annular recess 113 for disposing a seal member 150 is formed around the first through hole 115 on the lower surface 112 of the first ceramics member 110 . Both corners 113a of the annular recess 113 form an arc (R) shape in which the width dimension of the annular recess 113 increases from the bottom of the annular recess 113 toward the opening, as in the first embodiment. The dimensions of the annular recess 113 (corner 113a) are the same as the dimensions of the annular recess 13 (corner 13a).

A cylindrical third through hole 145 located between the first through hole 115 and the second through hole 125 is formed in the bonding layer 140 . The third through-hole 145 is coaxial with the first through-hole 115 and the second through-hole 125 (the central axis CL is coincident), and has a larger inner diameter than the first through-hole 115 and the second through-hole 125. ing.

A sealing member 150 is arranged in the annular recess 113 to protect the bonding layer 140 . The sealing member 150 has the central axis CL of the third through-hole 145 positioned inside its inner circumference so as to surround the first through-hole 115 and the second through-hole 125 when viewed in the Z-axis direction, and the first ceramics It is sandwiched between the lower surface 112 of the member 110 and the upper surface 121 of the second ceramics member 120 . Thus, the sealing member 150 hermetically seals the space between the lower surface 112 of the first ceramics member 110 exposed in the third through hole 145 and the upper surface 121 of the second ceramics member 120 . Therefore, the sealing member 150 can prevent plasma or the like that has flowed into the electrostatic chuck 1 b through the first through-hole 115 from entering the bonding layer 140 through the third through-hole 145 and contacting the bonding layer 40 .

Since both corners 113a of the annular recess 113 are formed in the same arc (R) shape as in the first embodiment, the volume of the first ceramic member 110 at both corners 113a of the annular recess 113 (in the Z-axis direction volume) increases. As a result, in the first ceramic member 110, heat conduction in the Z-axis direction near the annular recess 113 is averaged. Therefore, the heat conduction between the first ceramics member 110 and the second ceramics member 120 can be improved at the sealing portion where the sealing member 150 and the annular concave portion 113 are arranged. Therefore, in the sealing portion around the through-hole 30, the temperature distribution change (temperature gradient) on the holding surface 111 can be moderated, and the uniformity of heat on the holding surface 111 can be improved.

Moreover, since both corners 113a of the annular recess 113 are arc-shaped, stress concentration that tends to occur at both corners 113a of the annular recess 113 can be alleviated. Furthermore, since the difference in thermal expansion between the first ceramics member 110 and the second ceramics member 120 is small, the stress acting on the seal member 150 is reduced. Therefore, deterioration of the seal member 150 can be prevented, and corrosion resistance of the bonding layer 140 can be improved. Moreover, since the stress acting on the seal member 150 is reduced, the reaction force from the seal member 150 that the first ceramics member 110 receives from the seal member 150 is suppressed. Therefore, the stress concentration that tends to occur at both corners 113a of the annular recess 113 can be further alleviated. Therefore, damage to the first ceramics member 110 (plate-shaped member 100) can be effectively prevented, so that the reliability and durability of the electrostatic chuck 1b can be further improved.

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 is applicable to general holding devices that hold an object on a holding surface. be able to.

In the above-described embodiment, the sealing members 50 and 150 have circular cross-sections, but the cross-sectional shape of the sealing members 50 and 150 is not limited to this shape, and may be square, elliptical, or the like. may

Further, in the above-described embodiment, the corners 13a, 113a of the annular recesses 13, 113 are arc-shaped, but the corners 13a, 113a extend from the bottoms of the annular recesses 13, 113 toward the openings. Accordingly, the width dimension of the annular recesses 13 and 113 should be large, and the shape is not limited to an arc shape, and may be a tapered shape, a polygonal shape, or the like.

1 Electrostatic chuck 1a Electrostatic chuck 1b Electrostatic chuck 10 Plate member 11 Holding surface 12 Lower surface 13 Annular concave portion 13a Corner 15 First through hole 20 Base member 21 Upper surface 22 Lower surface 25 Second through hole 40 Bonding layer 45 Third Through-hole 50 Seal member 73 Annular recess 73a Corner 110 First ceramic member 113 Annular recess 120 Second ceramic member 150 Seal member CL Central axis W Semiconductor wafer

Claims (3)

A first member having a first surface and a second surface provided opposite to the first surface, a third surface, and a fourth member provided opposite to the third surface and a second member disposed between the second surface of the first member and the third surface of the second member to join the first member and the second member and a bonding layer that holds an object on the first surface of the first member,
The first member is formed with a first through hole penetrating the first surface and the second surface,
The second member is formed with a second through hole passing through the third surface and the fourth surface and communicating with the first through hole,
a third through-hole communicating with the first through-hole and the second through-hole is formed in the bonding layer,
When viewed from the lamination direction of the first member and the second member, the second surface and the third surface are arranged such that the center axis of the third through hole is located inside the inner circumference thereof. having an annular sealing member disposed between the surface of
An annular recess in which the seal member is arranged is formed on the second surface,
The holding device, wherein both corners of the recess are shaped such that the width of the recess increases from the bottom of the recess toward the opening of the recess. A holding device according to claim 1,
The holding device according to claim 1, wherein the width of the recess is the smallest at the opening, and the minimum dimension is smaller than the width of the seal member. In the holding device according to claim 1 or claim 2,
The holding device, wherein the first member and the second member are ceramic members.

Images