JP2022003667A - Holding device - Google Patents

Abstract

To provide a holding device capable of obtaining clear temperature distribution between an inner peripheral portion and an outer peripheral portion of the holding surface of a wafer.SOLUTION: A holding device includes a ceramic member 41 having a suction surface 51 and a lower surface 52 provided on the side opposite to the suction surface 51 in the Z-axis direction, and a base member 42 having an upper surface 61 and a lower surface 62 provided on the opposite side of the upper surface 61, and in an electrostatic chuck 10 in which the lower surface 52 of the ceramic member 41 and the upper surface 61 of the base member 42 are thermally connected to hold a wafer W on the surface of the suction surface 51 of the ceramic member 41, the base member 42 includes refrigerant flow paths 66 and 67 for flowing a refrigerant and an annular groove portion 63 when viewed from the Z-axis direction, and the ceramic member 41 has a heat insulating space 74 that is arranged so as to overlap the groove portion 63 when viewed from the Z-axis direction.SELECTED DRAWING: Figure 2

Description

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

As a conventional technique relating to a holding device, for example, in Patent Document 1, in order to obtain a clear temperature distribution by controlling the inner peripheral portion and the outer peripheral portion of the holding surface (wafer holding surface) of an object to different temperatures. A plasma processing apparatus is disclosed in which a concentric slit is provided in an electrode block so that heat transfer between an inner peripheral portion and an outer peripheral portion is suppressed.

Japanese Unexamined Patent Publication No. 2003-243371

However, in the above device, heat transfer in the radial direction inside the dielectric film (ceramics) cannot be suppressed. Therefore, due to the radial heat transfer inside the dielectric film, the temperature boundary (temperature difference) between the inner peripheral portion and the outer peripheral portion of the holding surface of the object becomes unclear, and a clear temperature distribution can be obtained. It may not be possible.

Therefore, the present disclosure has been made to solve the above-mentioned problems, and to provide a holding device capable of obtaining a clear temperature distribution between the inner peripheral portion and the outer peripheral portion of the holding surface of the object. The purpose.

A form of this disclosure made to solve the above problems is
A plate-like member having a first surface and a second surface provided on a side opposite to the first surface in the first direction, a third surface, and the opposite of the third surface. A base member including a fourth surface provided on the side is provided, and the second surface of the plate-shaped member and the third surface of the base member are thermally connected and the plate is provided. In the holding device for holding the object on the first surface of the shaped member,
The base member is
Refrigerant flow path for flowing refrigerant and
It has a first heat insulating portion that is annular when viewed from the first direction.
The plate-shaped member is characterized by having a second heat insulating portion arranged along 5% or more of the circumferential direction of the first heat insulating portion when viewed from the first direction.

In this holding device, since the second heat insulating portion is arranged on the plate-shaped member when viewed from the first direction, heat transfer in the second direction (diameter direction) in the plate-shaped member is suppressed. Heat transfer in the first direction can be promoted. In the base member, heat transfer in the second direction between the inner peripheral portion and the outer peripheral portion is suppressed with the first heat insulating portion as a boundary. Further, when viewed from the first direction, the second heat insulating portion is arranged around the first heat insulating portion, so that the inside of the plate-shaped member is inside the plate-shaped member with the temperature range formed by the base member almost unchanged. Since the temperature is transmitted in the direction of 1, a clear temperature distribution can be obtained between the inner peripheral portion and the outer peripheral portion on the first surface.

In the above-mentioned holding device,
A plurality of convex portions are formed on the first surface.
It is preferable that the convex portion is arranged so as not to overlap with the first heat insulating portion when viewed from the first direction.

In this holding device, the convex portion contacts the object and holds the object. Since this convex portion is not arranged directly above the first heat insulating portion, the temperature distribution between the inner peripheral portion and the outer peripheral portion becomes clearer on the first surface (contact surface with the object). Then, in the heat transfer between the plate-shaped member and the object, when the convex portion and the portion directly above the first heat insulating portion where the convex portion is not arranged are compared, the first heat insulating portion where the convex portion is not arranged is compared. It is harder to transfer heat directly above. As a result, the boundary where the temperature difference occurs between the inner peripheral portion and the outer peripheral portion of the plate-shaped member can be clearly seen, so that a clearer temperature distribution can be obtained between the inner peripheral portion and the outer peripheral portion on the first surface. ..

In the above-mentioned holding device,
The second heat insulating portion is the first from a groove formed on the first surface or a position of 1/3 of the thickness of the plate-shaped member from the second surface in the first direction. It is preferable that the internal cavity is arranged on the surface side of the above.

In this way, by forming the second heat insulating portion with the groove formed on the first surface or the internal cavity located above 1/3 of the thickness, the plate-shaped member is in the vicinity of the first surface. The heat transfer in the second direction (diameter direction) can be effectively suppressed. Therefore, heat transfer in the first direction is further promoted. Therefore, the temperature controlled by the inner peripheral portion and the outer peripheral portion of the base member is transmitted to the inside of the plate-shaped member in the first direction as it is, so that the inner peripheral portion and the outer peripheral portion can be obtained on the first surface. Since the temperature difference is clearly generated in, a clearer temperature distribution can be obtained between the inner peripheral portion and the outer peripheral portion.

Further, by forming the second heat insulating portion by the groove or the internal cavity, the second heat insulating portion can be provided to the plate-shaped member very easily. Then, for example, by using a gas tunnel conventionally formed in a plate-shaped member as an internal cavity, a second heat insulating portion can be provided in the plate-shaped member only by changing the shape and arrangement of the gas tunnel. ..

In the above-mentioned holding device,
The first surface of the plate-shaped member is
It has an inner region located inside the second heat insulating portion when viewed from the first direction, and an outer region located outside the second heat insulating portion when viewed from the first direction. ,
It is preferable that the inner refrigerant flow path for cooling the inner region and the outer refrigerant flow path for cooling the outer region are independently provided in the refrigerant flow path.

By doing so, the inner region and the outer region are provided with independent refrigerant flow paths, that is, the passage inlet and the passage outlet, respectively, and the temperature and flow velocity of the refrigerant can be changed separately. Since it can be cooled by the flow path and the inner region and the outer region are separated by the first heat insulating portion, the accuracy of temperature distribution control in the inner region and the outer region of the first surface can be further improved. Can be done. Therefore, on the first surface, a clearer temperature distribution can be obtained between the inner peripheral portion and the outer peripheral portion.

In the above-mentioned holding device,
When viewed from the first direction, it is preferable that the first heat insulating portion and the second heat insulating portion are arranged so as to overlap each other in the circumferential direction.

By doing so, since the second heat insulating portion is arranged directly above the first heat insulating portion, the inner region and the outer region of the base member substantially coincide with the inner region and the outer region of the first surface. Therefore, the temperature ranges controlled by the inner region and the outer region of the base member are directly reflected on the first surface. Therefore, since the controllability of the temperature distribution control on the first surface is further improved, it is possible to obtain a clearer temperature distribution on the inner peripheral portion and the outer peripheral portion on the first surface.

In the above-mentioned holding device,
A plurality of convex portions are formed on the first surface.
When the second heat insulating portion is the internal cavity, the convex portion is arranged more in the non-arranged region of the internal cavity than in the arranged region of the internal cavity when viewed from the first direction. It is preferable to be there. The number of convex portions may be compared by the number of convex portions arranged per unit area.

By doing so, there are few (or no) protrusions in the arrangement region of the internal cavity (which is also the arrangement region of the first stage heat portion), and even in the non-arrangement region of the internal cavity (the non-arrangement region of the first stage heat portion). There are many convex parts in). Therefore, in the portion where many convex portions are arranged, the contact area with the object becomes large, so that the heat transfer is improved and the temperature controllability can be improved. Therefore, the control temperature in the inner region and the outer region can be accurately changed on the first surface with the non-arranged region of the inner cavity as the boundary. Therefore, the inner peripheral portion and the outer peripheral portion on the first surface can be changed accurately. A clear temperature distribution can be obtained with.

According to the present disclosure, it is possible to provide a holding device capable of obtaining a clear temperature distribution between the inner peripheral portion and the outer peripheral portion of the holding surface of an object.

It is a schematic perspective view of the electrostatic chuck which concerns on 1st Embodiment. It is a schematic block diagram of the XZ cross section of the electrostatic chuck which concerns on 1st Embodiment. It is a schematic block diagram of the XY plane of the electrostatic chuck which concerns on 1st Embodiment. It is a schematic block diagram of the XZ cross section of the electrostatic chuck which concerns on 2nd Embodiment. (A) to (E) are schematic block diagrams of the XY planes of the electrostatic chuck according to the second embodiment.

[First Embodiment]
The holding device according to the present disclosure will be described in detail with reference to the drawings. In this embodiment, a case where it is applied to an electrostatic chuck that holds a semiconductor wafer will be described.

<Overall configuration of electrostatic chuck>
The electrostatic chuck of this embodiment will be described with reference to FIGS. 1 to 3. The electrostatic chuck 10 is a device that attracts and holds an object (for example, a wafer W) by electrostatic attraction, and is used, for example, for fixing a wafer W in a vacuum chamber of a semiconductor manufacturing apparatus. As shown in FIG. 1, the electrostatic chuck 10 has a ceramic member 41 which is a plate-shaped member, a base member 42, a bonding layer 43, and the like.

In the following description, for convenience of explanation, the XYZ axes are defined as shown in FIG. Here, the Z axis is the axis in the Ca direction (vertical direction in FIG. 1), which is the central axis of the electrostatic chuck 10, and the X axis and the Y axis are the radial axes of the electrostatic chuck 10. The Z-axis direction (that is, the central axis Ca direction) is an example of the "first direction" of the present disclosure, and the X-axis direction and the Y-axis direction (that is, the radial direction of the electrostatic chuck 10) are the present disclosure. This is an example of the "second direction" of.

The ceramic member 41 is, for example, a disk-shaped member and is made of ceramics. The ceramics, various ceramics are used, the strength and wear resistance, from the point of view of plasma resistance and the like, for example, aluminum oxide (alumina, Al 2 _{O 3)} or aluminum nitride (AlN) as a main component a ceramic Is preferably used. The main component referred to here means a component having the highest content ratio (for example, a component having a volume content of 90 vol% or more).

The diameter of the ceramic member 41 is, for example, about 150 mm to 300 mm, and the thickness of the ceramic member 41 is, for example, about 2 mm to 6 mm. The thermal conductivity of the ceramic member 41 is preferably in the range of 10 to 50 W / mK (more preferably 18 to 30 W / mK, for example, 20 W / mK).

As shown in FIGS. 1 and 2, the ceramic member 41 has a suction surface 51 on the upper surface and a lower surface 52 provided on the opposite side of the suction surface 51 in the central axis direction (that is, the Z-axis direction) of the ceramic member 41. And have. The ceramic member 41 holds the wafer W on the suction surface 51. The suction surface 51 is an example of the "first surface" of the present disclosure, and the lower surface 52 is an example of the "second surface" of the present disclosure.

As shown in FIGS. 2 and 3, an annular convex portion 71 is formed on the suction surface 51 in the vicinity of the outer edge thereof, and a plurality of independent columnar convex portions 72 are formed inside the annular convex portion 71. There is. The annular convex portion 71 is also called a seal band. As shown in FIG. 2, the shape of the cross section (XZ cross section) of the annular convex portion 71 is substantially rectangular. The height (dimension in the Z-axis direction) of the annular convex portion 71 is, for example, about 10 μm to 20 μm. The width (dimension in the X-axis direction) of the annular convex portion 71 is, for example, about 0.5 mm to 5.0 mm.

As shown in FIG. 3, the convex portions 72 have a substantially circular shape in the Z-axis direction, and are arranged at substantially equal intervals. Further, the shape of the cross section (XZ cross section) of each convex portion 72 is substantially rectangular as shown in FIG. The height of the convex portion 72 is substantially the same as the height of the annular convex portion 71, and is, for example, about 10 μm to 20 μm. The width of the convex portion 72 (the maximum diameter of the convex portion 72 in the Z-axis direction) is, for example, about 0.5 mm to 1.5 mm. The portion of the suction surface 51 of the ceramic member 41 where the convex portion 72 is not formed is a concave portion 73 inside the annular convex portion 71.

Then, the wafer W is supported by the annular convex portion 71 and the plurality of convex portions 72 on the suction surface 51 of the ceramic member 41 and is held by the electrostatic chuck 10. When the wafer W is held by the electrostatic chuck 10, a space exists between the surface (lower surface) of the wafer W and the suction surface 51 of the ceramic member 41 (more specifically, the recess 73 of the suction surface 51). Will be done. An inert gas (for example, helium gas) is supplied to this space.

The ceramic member 41 is provided with a chuck electrode (not shown) having a substantially circular shape, for example, in the Z-axis direction. Then, the chuck electrode generates an electrostatic attraction when a voltage is applied from a power source (not shown), and the wafer W is attracted to and held on the suction surface 51 by the electrostatic attraction.

The base member 42 is, for example, a cylinder as shown in FIG. 1, specifically, two cylinders having different diameters are arranged so that a lower surface portion of a small diameter cylinder is placed on an upper surface portion of a large diameter cylinder. It is a stepped columnar shape formed by stacking the central axis Ca in common. The base member 42 is preferably formed of a metal (for example, aluminum, an aluminum alloy, etc.), but may be other than the metal.

Then, as shown in FIGS. 1 and 2, the base member 42 has an upper surface 61 and an upper surface 61 in the central axis Ca (see FIG. 2) direction (that is, the Z-axis direction) of the base member 42 (ceramic member 41). Is provided with a lower surface 62 provided on the opposite side. The upper surface 61 is an example of the "third surface" of the present disclosure, and the lower surface 62 is an example of the "fourth surface" of the present disclosure.

The diameter of the base member 42 is, for example, about 150 mm to 300 mm in the upper part and about 180 mm to 350 mm in the lower part. The thickness of the base member 42 (dimensions in the Z-axis direction) is, for example, about 20 mm to 50 mm. The thermal conductivity of the base member 42 (assuming aluminum) is larger than that of the ceramic member 41, and is preferably in the range of 180 to 250 W / mK (preferably about 230 W / mK).

The base member 42 is joined to the ceramic member 41 by a bonding layer 43 arranged between the lower surface 52 of the ceramic member 41 and the upper surface 61 of the base member 42. The bonding layer 43 is made of an adhesive material such as a silicone resin, an acrylic resin, or an epoxy resin. The thickness of the bonding layer 43 (dimensions in the Z-axis direction) is, for example, about 0.1 mm to 1.0 mm. The thermal conductivity of the bonding layer 43 is, for example, 1.0 W / mK. The thermal conductivity of the bonding layer 43 (assuming a silicone resin) is preferably in the range of 0.1 to 2.0 W / mK (preferably 0.5 to 1.5 W / mK).

As shown in FIG. 2, the base member 42 is provided with a groove portion 63 extending in the lower surface 52 direction along the central axis Ca (see FIG. 2) (that is, the Z axis) from the upper surface 61 at a substantially intermediate position in the radial direction. Has been done. Further, as shown in FIG. 3, the groove portion 63 extends in an annular shape about the central axis Ca of the base member 42. Therefore, the base member 42 is divided by the groove portion 63 into an inner region 64 located inside the groove portion 63 and an outer region 65 located outside the groove portion 63.

Further, the depth of the groove portion 63, that is, the length from the upper surface 61 of the base member 42 to the bottom surface of the groove portion 63 along the central axis Ca is about 1/10 of the thickness of the base member 42, preferably 1. About / 3 is desirable. Specifically, for example, if the thickness of the base member 42 is about 20 mm, it is preferably about 2 mm to 7 mm, and if the thickness of the base member 42 is about 50 mm, it is preferably about 5 mm to 17 mm.

Further, the width of the groove portion 63 in the radial direction (that is, in the X-axis direction or the Y-axis direction) is preferably about 5 mm to 35 mm. The groove portion 63 is an example of the "first heat insulating portion" of the present disclosure.

Further, as shown in FIG. 2, the inner region 64 of the base member 42 is provided with an inner refrigerant passage 66 for flowing a refrigerant (for example, a fluorine-based inert liquid, water, etc.). The inner refrigerant passage 66 is spirally arranged in the inner region 64 of the base member 42 with the central axis Ca (that is, the Z axis) as the center in the Z-axis direction. Further, the inner refrigerant passage 66 is connected to a supply port and a discharge port (not shown) provided on the lower surface 62 of the base member 42, and therefore, the refrigerant supplied to the base member 42 from the supply port is an inner refrigerant. It flows through the passage 66 and is discharged to the outside of the base member 42 from the discharge port. By flowing the refrigerant through the inner refrigerant passage 66 in this way, the inner region 64 of the base member 42 can be cooled.

Further, as shown in FIG. 2, the outer region 65 of the base member 42 is provided with an outer refrigerant passage 67 for flowing a refrigerant (for example, a fluorine-based inert liquid, water, etc.). The outer refrigerant passage 67 is spirally arranged in the outer region 65 of the base member 42 in the Z-axis direction. That is, the outer refrigerant passage 67 is located outside the inner refrigerant passage 66 with the annular groove 63 interposed therebetween. Further, the outer refrigerant passage 67 is connected to a supply port and a discharge port (not shown) provided on the lower surface 62 of the base member 42, and the refrigerant supplied to the base member 42 from the supply port is the outer refrigerant passage 67. It flows inside and is discharged to the outside of the base member 42 from the discharge port. By flowing the refrigerant through the outer refrigerant passage 67 in this way, the outer region 65 of the base member 42 can be cooled.

As described above, in the present embodiment, the inner refrigerant passage 66 provided in the inner region 64 and the outer refrigerant passage 67 provided in the outer region 65 are provided independently in the control system, and each of them has a refrigerant. It is possible to adjust the temperature of the refrigerant and the flow velocity of the refrigerant. The base member 42 is provided with a groove 63 between the inner region 64 and the outer region 65. Therefore, when the refrigerant is passed through the outer refrigerant passage 67, the outer region 65 of the base member 42 is cooled independently, and when the refrigerant is passed through the inner refrigerant passage 66, the inner region 64 of the base member 42 is independently cooled. Will be. At this time, since the base member 42 is provided with the annular groove portion 63, the inner region 64 is not affected by the temperature of the outer region 65, and the outer region 65 is the temperature of the inner region 64. Can be cooled without being affected by. Therefore, a desired clear temperature distribution can be obtained in the inner region 64 and the outer region 65 of the base member 42.

As shown in FIG. 2, a heat insulating space 74 is provided inside the ceramic member 41. Further, as shown in FIG. 3, the heat insulating space 74 extends in an annular shape with the central axis Ca (that is, the Z axis) as the center. Therefore, the ceramic member 41 is divided into an inner region 75 located inside the heat insulating space 74 and an outer region 76 located outside the heat insulating space 74 by the heat insulating space 74.

Further, as shown in FIG. 3, the heat insulating space 74 is joined to the ceramic member 41 via the bonding layer 43 to the base member 42, and the groove portion 63 is viewed in the Z-axis direction as shown in FIG. That is, they are arranged so as to overlap with each other, that is, along almost the entire circumference (for example, 90% or more) in the circumferential direction. That is, in the present embodiment, in the Z-axis direction view, the center in the width direction of the heat insulating space 74 is arranged so as to coincide with the center in the width direction of the groove portion 63 over almost the entire circumference in the circumferential direction. There is.

In the present embodiment, in the Z-axis direction view, the center in the width direction of the heat insulating space 74 is arranged so as to coincide with the center in the width direction of the groove 63 over almost the entire circumference in the circumferential direction. However, it is not limited to that. That is, for example, in the Z-axis direction view, the center in the width direction of the heat insulating space 74 may be displaced inward with respect to the center in the width direction of the groove 63, or may be displaced in the outward direction. Needless to say, there is no problem.

Further, the length of the heat insulating space 74 in the direction of the central axis Ca is preferably about 1/4 to 1/2, preferably about 1/3 of the thickness of the ceramic member 41. Specifically, for example, if the thickness of the ceramic member 41 is about 2 mm, it is preferably about 0.5 mm to 1 mm, and if the thickness of the ceramic member 41 is about 6 mm, it is preferably about 1.5 mm to 3 mm. ..

Further, as shown in FIG. 2, the bottom portion of the heat insulating space 74 is spaced from the lower surface 52 of the ceramic member 41 to the suction surface 51 side by a length of 1/3 of the thickness of the ceramic member 41. It is arranged.

Further, the width of the heat insulating space 74 in the radial direction (that is, the X-axis direction and the Y-axis direction) is set wider than the width of the groove portion 63, and is preferably about 15 mm to 35 mm. The heat insulating space 74 is an example of the "second heat insulating portion" of the present disclosure.

As shown in FIG. 2, the lower surface 52 of the ceramic member 41 in the inner region 75 and the outer region 76 and the upper surface 61 of the base member 42 in the inner region 64 and the outer region 65 are arranged between the joint layer 43. Is thermally connected by.

On the other hand, since the bonding layer 43 is not arranged in the annular opening portion of the groove portion 63 on the upper surface 61 of the base member 42, the ceramic member 41 is formed in the opening portion of the groove portion 63 on the upper surface 61 of the base member 42. The lower surface 52 and the upper surface 61 of the base member 42 are not thermally connected.

Further, as shown in FIGS. 2 and 3, a large number of columnar convex portions 72 are provided on the suction surface 51 of the ceramic member 41 corresponding to the inner region 75 and the outer region 76 in the Z-axis direction. There is. Therefore, in a state where the wafer W is supported by the annular convex portion 71 on the suction surface 51 of the ceramic member 41 and the plurality of convex portions 72, that is, all the convex portions formed on the suction surface 51, the inside of the ceramic member 41. The suction surface 51 in the region 75 and the outer region 76 and the wafer W are thermally connected to each other via the annular convex portion 71 and the plurality of convex portions 72.

On the other hand, the columnar convex portion 72 is not provided on the suction surface 51 portion of the ceramic member 41 that overlaps with the groove portion 63, that is, overlaps with the heat insulating space 74 in the Z-axis direction. Therefore, the wafer W and the ceramic member 41 are not thermally connected.

In the electrostatic chuck 10 configured as described above, the refrigerant can be supplied from the supply port to the inner refrigerant passage 66 and the outer refrigerant passage 67, whereby the temperature of the base member 42 can be controlled. Specifically, the temperature of the inner region 64 of the base member 42 can be controlled by changing the temperature of the refrigerant supplied from the supply port to the inner refrigerant passage 66 and the flow velocity of the refrigerant. Further, the temperature of the outer region 65 of the base member 42 can be controlled by changing the temperature of the refrigerant supplied from the supply port to the outer refrigerant passage 67 and the flow velocity of the refrigerant.

At this time, in the present embodiment, since the annular groove portion 63 is provided between the inner region 64 and the outer region 65 of the base member 42, the base member 42 has the inner region 64 and the outer region 65 with the groove portion 63 as a boundary. The heat transfer in the radial direction between them is suppressed. As a result, the controllability of the temperature distribution control in the inner region 64 and the outer region 65 is further improved, and therefore, the upper surface 61 of the inner region 64 and the upper surface 61 of the outer region 65 of the base member 42 are more clear. The temperature distribution can be obtained.

Further, the temperature of the upper surface 61 of the inner region 64 of the base member 42 is the temperature of the first heat transfer path extending in the central axis Ca direction, specifically, the bonding layer 43, the inner region 75 of the ceramic member 41, and a large number of columns. Heat is transferred to the wafer W via the convex portion 72 of the above. Therefore, the temperature of the suction surface 51 corresponding to the inner region 75 of the ceramic member 41, that is, the inner region 75 of the ceramic member 41, is determined by changing the temperature of the refrigerant supplied from the supply port to the inner refrigerant passage 66 and the flow velocity of the refrigerant. , The temperature can be easily controlled.

Further, the temperature of the upper surface 61 of the outer region 65 of the base member 42 is a second heat transfer path extending annularly in the central axis Ca direction outside the first heat transfer path, specifically, an annular joint. Heat is transferred to the wafer W via the layer 43, the annular outer region 76 of the ceramic member 41, and a large number of columnar protrusions 72. Therefore, the temperature of the suction surface 51 corresponding to the outer region 76 of the ceramic member 41, that is, the outer region 76 of the ceramic member 41, is determined by changing the temperature of the refrigerant supplied from the supply port to the outer refrigerant passage 67 and the flow velocity of the refrigerant. , The temperature can be easily controlled.

At this time, in the present embodiment, the heat insulating space 74 is provided in the portion of the ceramic member 41 that overlaps with the groove portion 63, and the suction surface that overlaps with the groove portion 63 in the Z-axis direction, that is, overlaps with the heat insulating space 74. Since the columnar convex portion 72 is not formed in the 51 portion, and the bonding layer 43 is not arranged in the annular opening portion of the groove portion 63 in the upper surface 61 of the base member 42, the first Radial heat transfer between the heat transfer path and the second heat transfer path is suppressed. Therefore, the temperature formed on the upper surface 61 of the base member 42 is heat-transferred to the wafer W in a state of being substantially unchanged, and therefore a clear temperature distribution can be obtained in the inner region and the outer region of the wafer W.

Further, by changing the temperature of the refrigerant supplied from the supply port to the inner refrigerant passage 66 and the outer refrigerant passage 67 and the flow velocity of the refrigerant, it is possible to accurately control the temperature between the inner region and the outer region of the wafer W. ..

[Second Embodiment]
Subsequently, the holding device according to the second embodiment of the present disclosure will be described in detail with reference to FIGS. 4 and 5 (A) to 5 (E). In the description thereof, those having the same action and effect as those of the first embodiment will be described with the same reference numerals.

That is, in the first embodiment, the heat insulating space 74 provided in the ceramic member 41 is provided to suppress heat transfer between the inner region 75 and the outer region 76 of the ceramic member 41. In the form, as shown in FIG. 4, the heat insulating space 74 is different in that it is composed of a gas tunnel (He tunnel) 74. He gas is discharged to the suction surface 51 by such a gas tunnel 74, and the He gas is filled between the wafer W and the suction surface 51, so that even in a place where there is no convex portion 72, the He gas is passed through. Heat transfer between the wafer W and the suction surface 51 is possible. Note that FIG. 4 shows a cross-sectional view of the holding device of FIG. 5B as an example of a cross-sectional view of the holding device according to the second embodiment.

In order to make the gas tunnel also serve as the heat insulating space 74, it is necessary to devise the shape and arrangement of the gas tunnel, and the details thereof will be described below with reference to FIG. In the following description, the heat insulating space 74 will be described as a gas tunnel 74. Further, in FIGS. 5A to 5E, the groove portion 63 formed in the base member 42 and the gas tunnel 74 formed in the ceramic member 41 are schematically shown by one line.

First, as shown in FIG. 5A, the gas tunnel 74 has a gas supply port 74A and a supply path 74B extending from the supply port 74A toward the gas tunnel 74. Further, the gas tunnel 74 is arranged so as to be interrupted on the side opposite to the portion to which the supply path 74B is connected. Therefore, the gas tunnel 74 is not arranged over the entire circumference in the circumferential direction of the groove portion 63, and there is a portion in which the gas tunnel 74 is not arranged along the circumferential direction of the groove portion 63.

In this case, if the circumferential length of the gas tunnel 74 is 5% or more of the circumferential length of the groove 63, heat transfer between the inner region 75 and the outer region 76 of the ceramic member 41 is suppressed. It is possible to do.

In FIG. 5A, the gas tunnel 74 formed in the ceramic member 41 is arranged on the inner peripheral side with respect to the groove 63 formed in the base member 42, but the gas is viewed in the Z-axis direction. The center in the width direction of the tunnel 74 may be arranged so as to coincide with the center in the width direction of the groove portion 63 over the entire circumference in the circumferential direction, or may be arranged on the outer peripheral side. The same applies to FIGS. 5 (B) to 5 (E) below.

Further, as shown in FIG. 5B, the gas tunnel 74 is divided into four parts in the circumferential direction of the groove portion 63. Further, a supply path 74B is connected from the supply port 74A to the central portion of each of the gas tunnels 74 divided into four parts. Further, discharge ports 74C are formed at both ends of each of the gas tunnels 74 divided into four parts. Therefore, at each end of a divided gas tunnel 74, there is a gap between the ends of the adjacent gas tunnels 74. As a result, the gas tunnel 74 divided into four does not exist over the entire circumference of the groove 63 in the circumferential direction, and the groove is formed between each end of the gas tunnel 74 and the end of the adjacent gas tunnel 74. The gas tunnel 74 is not arranged along the circumferential direction of 63.

In this case, if the circumferential length of the gas tunnel 74 is 5% or more of the circumferential length of the groove 63, heat transfer between the inner region 75 and the outer region 76 of the ceramic member 41 is suppressed. It is possible to do.

In FIG. 5B, the gas tunnel 74 formed in the ceramic member 41 is arranged on the inner peripheral side with respect to the groove 63 formed in the base member 42, but the gas is viewed in the Z-axis direction. The center in the width direction of the tunnel 74 may be arranged so as to coincide with the center in the width direction of the groove portion 63 over the entire circumference in the circumferential direction, or may be arranged on the outer peripheral side.

Further, as shown in FIG. 5C, the gas tunnel 74 meanders from the inner peripheral side of the groove 63 to the outer peripheral side of the groove 63 so as to straddle the groove 63, and then straddles the groove 63 again. It is arranged in a meandering manner on the inner peripheral side of the groove portion 63. Therefore, the gas tunnel 74 is not arranged along the groove 63 in the portion where the gas tunnel 74 greatly overhangs on the inner peripheral side or the outer peripheral side.

In this case, since the gas tunnel 74 is arranged over the entire circumference of the groove portion 63, it is possible to suppress heat transfer between the inner region 75 and the outer region 76 of the ceramic member 41, but the groove portion. Depending on the width of the meandering of 63, the inner region 64 and the outer region 65 of the base member 42 and the inner region 75 and the outer region 76 of the ceramic member 41 may not match in the Z-axis direction. However, depending on the width of the meandering of the groove portion 63, the width in the radial direction (that is, the X-axis direction and the Y-axis direction) of the gas tunnel 74 may be narrower than the width of the heat insulating space 74 of the first embodiment, or This can be solved by making the width of the groove 63 in the radial direction (that is, the X-axis direction and the Y-axis direction) wider than the width of the groove 63 in the first embodiment (that is, the X-axis direction and the Y-axis direction). Is.

Further, as shown in FIG. 5D, the gas tunnel 74 extends on the inner peripheral side of the groove portion 63 over the entire circumference in the circumferential direction of the groove portion 63. Further, the supply path 74B extends from the supply port 74A arranged on the outer peripheral side of the groove portion 63 so as to straddle the groove portion 63, and then is connected to the gas tunnel 74.

Even if the supply port 74A is arranged on the outer peripheral side of the groove portion 63 in this way, since the gas tunnel 74 is arranged over the entire circumference of the groove portion 63, the inner region 75 and the outer region 76 of the ceramic member 41 It is possible to suppress heat transfer between them. Also in FIG. 5D, the gas tunnel 74 formed in the ceramic member 41 is arranged on the inner peripheral side with respect to the groove portion 63 formed in the base member 42, but the gas is viewed in the Z-axis direction. The center in the width direction of the tunnel 74 may be arranged so as to coincide with the center in the width direction of the groove portion 63 over the entire circumference in the circumferential direction, or may be arranged on the outer peripheral side.

Further, as shown in FIG. 5 (E), the gas tunnel 74 extends in the circumferential direction of the groove portion 63 on the inner peripheral side of the groove portion 63, but intersects the groove portion 63 in a part of the gas tunnel 74. It extends on the outer peripheral side of the groove portion 63 so as to do so. Therefore, the gas tunnel 74 extending on the outer peripheral side of the groove 63 so as to intersect the groove 63 is not arranged along the groove 63.

In this case, if the circumferential length of the gas tunnel 74 excluding the portion extending on the outer peripheral side of the groove 63 is 5% or more of the circumferential length of the groove 63, the inner region of the ceramic member 41 It is possible to suppress heat transfer between the 75 and the outer region 76.

In FIG. 5E, the gas tunnel 74 formed in the ceramic member 41 is arranged on the inner peripheral side with respect to the groove 63 formed in the base member 42, but the gas is viewed in the Z-axis direction. The center in the width direction of the tunnel 74 may be arranged so as to coincide with the center in the width direction of the groove portion 63 over the entire circumference in the circumferential direction, or may be arranged on the outer peripheral side. In this case, the portion extending on the outer peripheral side of the groove portion 63 in FIG. 5E may be extended to the inner peripheral side.

As described above, in the present embodiment, the shape and arrangement of the gas tunnel 74 are devised so that the gas tunnel 74 can also be used as a heat insulating space. However, in any of the cases described above, the gas tunnel 74 is made of ceramics. It is possible to suppress heat transfer between the inner region 75 and the outer region 76 of the member 41.

It should be noted that the above embodiment is merely an example and does not limit the present disclosure in any way, and it goes without saying that various improvements and modifications can be made without departing from the gist thereof. For example, in the present embodiment, the chuck electrode is exemplified as the internal electrode that sucks and holds the wafer W on the suction surface 51, but the internal electrode is not limited to the chuck electrode and may be a high frequency electrode.

Further, in the present embodiment, the ceramic member 41 is not provided with a heater for heating the ceramic member 41, but a heater may be provided. In this case, it is desirable to dispose separate heaters having different control systems in the inner region 75 and the outer region 76 on the lower surface 62 side of the heat insulating space 74 in the ceramic member 41.

Further, in the present embodiment, the first heat insulating portion is configured by an annular groove portion 63 extending from the upper surface 61 of the base member 42 toward the lower surface 62 along the central axis Ca, but the present invention is not limited thereto. .. For example, it may be an annular heat insulating space formed inside the base member 42, or may be formed by an annular groove portion extending from the lower surface 62 of the base member 42 toward the upper surface 61 along the central axis Ca. .. In this case, it is desirable that the bottom surface of the heat insulating space is arranged at a distance on the upper surface 61 side by the length of 1/3 of the thickness of the base member 42. Further, it is desirable that the annular groove portion extends from the lower surface 62 toward the upper surface 61 side along the central axis Ca by a length of 1/3 of the thickness of the base member 42.

Further, in the present embodiment, the second heat insulating portion is configured by the heat insulating space 74 formed in the ceramic member 41, but the present invention is not limited to this. For example, it may be configured by an annular groove portion extending from the suction surface 51 of the ceramic member 41 toward the lower surface 52 along the central axis Ca. In this case, it is desirable that the annular groove portion extends from the suction surface 51 toward the lower surface 52 side along the central axis Ca by a length of 1/3 of the thickness of the base member 42.

Further, in the present embodiment, a large number of columnar convex portions 72 are provided on the suction surface 51 corresponding to the inner region 75 and the outer region 76 in the Z-axis direction of the ceramic member 41, and the groove portion 63 and the groove portion 63. The suction surface 51 portion that overlaps, that is, overlaps with the heat insulating space 74, is not provided with the columnar convex portion 72, but is not limited thereto. For example, in the Z-axis direction view, the suction surface 51 corresponding to the inner region 75 and the outer region 76 is provided with a large number of columnar convex portions 72, and the suction surface overlaps with the groove portion 63, that is, overlaps with the heat insulating space 74. The 51 portion may be provided with the convex portions 72 so that the number of the convex portions 72 per unit area is smaller than the number of the convex portions 72 provided on the suction surface 51 corresponding to the inner region 75 and the outer region 76. ..

10 Electrostatic chuck 41 Ceramic member 42 Base member 51 Adsorption surface 52 Lower surface 61 Upper surface 62 Lower surface 63 Groove 66 Inner refrigerant passage 67 Outer refrigerant passage 72 Convex portion 74 Insulated space (gas tunnel)
75 Inner area (ceramic member)
76 Outer area (ceramic member)
W wafer

Claims (6)

A plate-like member having a first surface and a second surface provided on a side opposite to the first surface in the first direction, a third surface, and the opposite of the third surface. A base member including a fourth surface provided on the side is provided, and the second surface of the plate-shaped member and the third surface of the base member are thermally connected and the plate is provided. In the holding device for holding the object on the first surface of the shaped member,
The base member is
Refrigerant flow path for flowing refrigerant and
It has a first heat insulating portion that is annular when viewed from the first direction.
The holding device is characterized in that the plate-shaped member has a second heat insulating portion arranged along 5% or more of the circumferential direction of the first heat insulating portion when viewed from the first direction. In the holding device according to claim 1,
A plurality of convex portions are formed on the first surface.
A holding device characterized in that the convex portion is arranged so as not to overlap with the first heat insulating portion when viewed from the first direction. In the holding device according to claim 1 or 2.
The second heat insulating portion is the first from a groove formed on the first surface or a position of 1/3 of the thickness of the plate-shaped member from the second surface in the first direction. A holding device characterized by being an internal cavity arranged on the surface side of the. In any one of the holding devices according to claim 1 to claim 3.
The first surface of the plate-shaped member is
It has an inner region located inside the second heat insulating portion when viewed from the first direction, and an outer region located outside the second heat insulating portion when viewed from the first direction. ,
The holding device is characterized in that the inner refrigerant flow path for cooling the inner region and the outer refrigerant flow path for cooling the outer region are independently provided in the refrigerant flow path. In any one of the holding devices according to claim 1 to claim 4.
A holding device characterized in that the first heat insulating portion and the second heat insulating portion are arranged so as to overlap each other in the circumferential direction when viewed from the first direction. In the holding device according to claim 1,
A plurality of convex portions are formed on the first surface.
When the second heat insulating portion is the internal cavity, the convex portion is arranged more in the non-arranged region of the internal cavity than in the arranged region of the internal cavity when viewed from the first direction. A holding device characterized by being present.

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