JP7299756B2 - holding device - Google Patents

Description

The technology disclosed in this specification relates to a holding device that holds an object.

For example, an electrostatic chuck is used as a holding device for holding a wafer when manufacturing semiconductors. The electrostatic chuck is formed of, for example, ceramics, and includes a plate-like member having a surface (hereinafter referred to as "attraction surface") substantially orthogonal to a predetermined direction (hereinafter referred to as "first direction"), and a plate-like member having A chuck electrode is arranged inside the member, and the wafer is attracted and held on the attracting surface of the plate-shaped member using electrostatic attraction generated by applying a voltage to the chuck electrode.

If the temperature of the wafer held on the attraction surface of the electrostatic chuck does not reach the desired temperature, the precision of each process (film formation, etching, etc.) on the wafer may decrease. The ability to control the distribution is required. Therefore, a heater electrode is provided inside the plate-like member, and the temperature distribution of the attraction surface of the plate-like member is controlled (and the temperature distribution of the wafer held on the attraction surface) is controlled by heating by the heater electrode. . The heater electrode is composed of a resistance heating element extending in a direction substantially orthogonal to the first direction (hereinafter referred to as "plane direction").

In an electrostatic chuck, at least part of a plate member is divided into a plurality of virtual portions (hereinafter referred to as "segments") aligned in the surface direction in order to improve controllability of the temperature distribution of the attraction surface, A configuration in which a heater electrode is arranged in each segment may be employed. According to such a configuration, the temperature of each segment can be individually controlled by individually controlling the voltage applied to the heater electrodes arranged in each segment of the plate-like member. Controllability of temperature distribution can be improved. In recent years, in order to control the temperature of the attraction surface with higher accuracy, there is an increasing demand for increasing the number of segment divisions.

Here, in order to pass the required amount of current to the heater electrode for use as an electrostatic chuck, it is necessary to secure a cross-sectional area of the heater electrode equal to or larger than a predetermined value. is difficult to make smaller than necessary. In addition, if the number of segments in the electrostatic chuck is increased, the area of each segment when viewed in the first direction becomes smaller, making it difficult to extend the wire length of the heater electrode. Therefore, the resistance value of the heater electrode arranged in each segment cannot be made sufficiently high. If the resistance value of each heater electrode is low when a predetermined voltage is applied, the current value flowing through each heater electrode increases in order to obtain the desired wattage. Therefore, it is not preferable.

Conventionally, in each segment, a plurality of resistance heating elements having different positions in the first direction are connected in series to constitute one heater electrode, thereby increasing the resistance value of the heater electrode arranged in each segment. Techniques for heightening are known (see, for example, Patent Document 1).

WO2018/143288

As described above, in the electrostatic chuck, if the number of segment divisions is increased in order to control the temperature of the attraction surface with higher accuracy, the area of each segment as viewed in the first direction becomes smaller. Therefore, in the conventional technique described above, in order to increase the resistance value of the heater electrode arranged in each segment, a plurality of resistance heating elements (a plurality of resistance heating elements having different positions in the first direction) constituting the heater electrode are used. ) (the number of layers) must be increased, and therefore the thickness of the plate member in the first direction must be increased. If the thickness of the plate-shaped member becomes thicker, the heat mass becomes larger, which slows down the heating/cooling rate, or the dielectric loss becomes larger, which makes it difficult for the plasma to escape, which is not preferable.

Such a problem is not limited to an electrostatic chuck that holds a wafer using electrostatic attraction. This is a common problem with any holding device that holds an object on the surface of a member.

This specification discloses a technology capable of solving the above-described problems.

The technology disclosed in this specification can be implemented, for example, in the following forms.

(1) A holding device disclosed in this specification includes a plate-like member having a first surface substantially perpendicular to a first direction, and at least a portion of the plate-like member perpendicular to the first direction. a main heater electrode arranged in each of the main segments when virtually divided into a plurality of main segments aligned in a direction and configured by a resistance heating element, on the first surface of the plate member; a sub-heater arranged in each sub-segment obtained by virtually dividing each main segment into a plurality of sub-segments arranged in a direction perpendicular to the first direction an electrode, a driver electrode provided for each main heater electrode and electrically connected to the main heater electrode, and a driver electrode provided for each main heater electrode and electrically connected to the driver electrode in the main heater electrode. a first terminal member electrically connected to an end portion opposite to the end portion on the side of the sub-heater; a second terminal member electrically connected to the end opposite to the end, and a set of the sub-heater electrodes arranged in each of the sub-segments belonging to one of the main segments. The plurality of sub-heater electrodes constituting the sub-heater electrode group are arranged in parallel with each other, and the sub-heater electrode group arranged in one main segment is arranged in one main segment via the driver electrode. It is connected in series with the arranged main heater electrode.

In this holding device, each main segment is virtually divided into a plurality of sub-segments, and each sub-segment is provided with sub-heater electrodes electrically connected to the second terminal members and in parallel with each other. there is Therefore, by individually controlling the power supply to each sub-heater electrode, it is possible to achieve finer temperature control in sub-segment units than in main-segment unit temperature control. Controllability of surface temperature distribution can be improved.

Further, in this holding device, the sub-heater electrode group is connected in series with the main heater electrode. Therefore, compared to the configuration in which the holding device includes only the main heater electrode (one layer) and the configuration in which the holding device includes only the sub-heater electrode (one layer), the gap between the first terminal member and the second terminal member is reduced. The resistance of the heater electrode can be increased. Therefore, according to this holding device, when a predetermined voltage is applied, a desired wattage can be obtained without increasing the current value flowing through each heater electrode, that is, without increasing the size of the power supply, cables, and the like. can be done.

In addition, in this holding device, each main segment is virtually divided in the direction orthogonal to the first direction to form a plurality of sub-segments. Large area. Therefore, increasing the resistance of the main heater electrode arranged in the main segment can be easily realized. Therefore, according to the present holding device, compared to the case where one heater electrode is configured by connecting in series a plurality of resistance heating elements whose positions in the first direction are different for each sub-segment, the plate-like member thickening can be suppressed.

From the above, according to the present holding device, the controllability of the temperature distribution on the first surface of the plate-like member can be achieved by realizing temperature control in units of sub-segments that are finer than temperature control in units of main segments. while improving the thickness of the plate-like member compared to the case where one heater electrode is configured by connecting in series a plurality of resistance heating elements whose positions in the first direction are different in sub-segment units. It is possible to reduce the thickness of the first terminal member and the second terminal compared to a configuration in which the holding device includes only the main heater electrode (one layer) and a configuration in which the holding device includes only the sub-heater electrode (one layer). The resistance of the heater electrode between the members can be increased.

(2) In the above holding device, the plurality of sub-heater electrodes forming the group of sub-heater electrodes arranged in one main segment are resistors forming the main heater electrodes arranged in one main segment. A configuration may be adopted in which a resistance heating element having a resistance lower than that of the heating element is used. According to this holding device, the resistance of the heater electrode between the first terminal member and the second terminal member can be effectively increased.

(3) In the above-described holding device, each of the sub-heater electrodes arranged in each of the sub-segments belonging to one of the main segments has substantially the same amount of heat generated per unit area when viewed in the first direction. may be configured. According to this holding device, it is possible to realize highly accurate temperature control in sub-segment units, and to effectively improve the controllability of the temperature distribution on the first surface of the plate member.

(4) In the above holding device, each of the main heater electrodes is arranged at a first position in the first direction, and each of the sub-heater electrodes is positioned from the first position in the first direction. It may be arranged at a second position close to the first surface. According to this holding device, the sub-heater electrodes arranged in the sub-segments that are finer than the main segments are arranged closer to the first surface than the main-heater electrodes arranged in the main segments. By controlling the temperature in units of sub-segments by switching the power supply to the sub-heater electrodes, the controllability of the temperature distribution on the first surface of the plate member can be further effectively improved.

(5) In the above holding device, each of the main heater electrodes is arranged at a first position in the first direction, and each of the sub-heater electrodes is arranged at a position different from the first position in the first direction. Arranged at different second positions, each of the driver electrodes may be arranged at a third position different from the first position and the second position in the first direction. According to this holding device, compared with a configuration in which the driver electrodes are arranged at the same positions as the main heater electrodes or the sub-heater electrodes in the first direction, the degree of freedom in setting the pattern of the driver electrodes is improved. , the degree of freedom in pattern setting of the main heater electrode and the sub-heater electrode is also improved. Therefore, according to this holding device, more suitable patterns of the main heater electrode and the sub-heater electrode can be realized, so that the controllability of the temperature distribution on the first surface of the plate member can be further effectively improved.

It should be noted that the technology disclosed in this specification can be implemented in various forms, for example, in the form of a holding device, an electrostatic chuck, a vacuum chuck, manufacturing methods thereof, and the like. be.

1 is a perspective view schematically showing the external configuration of an electrostatic chuck 100 according to this embodiment; FIG. Explanatory view schematically showing the XZ cross-sectional configuration of the electrostatic chuck 100 according to the present embodiment. Explanatory drawing schematically showing the XY plane configuration of the electrostatic chuck 100 in the present embodiment. Explanatory drawing schematically showing the configuration of the main heater electrode layer 60, the sub-heater electrode layer 50, the driver electrode layer 70, etc. Explanatory drawing schematically showing the XY cross-sectional configuration of one main heater electrode 600 arranged in one main segment MSE. Explanatory drawing schematically showing the XY cross-sectional configuration of the sub-heater electrodes 500 arranged in each of the four sub-segments SSE set in one main segment MSE. Explanatory drawing schematically showing the XY cross-sectional configuration of one driver electrode 700 provided for one main segment MSE.

A. This embodiment:
A-1. Configuration of electrostatic chuck 100:
FIG. 1 is a perspective view schematically showing the external configuration of an electrostatic chuck 100 according to the present embodiment, and FIG. 2 is an explanatory view schematically showing the XZ cross-sectional configuration of the electrostatic chuck 100 according to the present embodiment. 3 is an explanatory view schematically showing the XY plane (upper surface) configuration of the electrostatic chuck 100 in this embodiment. Each figure shows mutually orthogonal XYZ axes for specifying directions. In this specification, for the sake of convenience, the positive direction of the Z-axis is referred to as the upward direction, and the negative direction of the Z-axis is referred to as the downward direction. may be

The electrostatic chuck 100 is a device that attracts and holds an object (for example, a wafer W) by electrostatic attraction, and is used, for example, to fix the wafer W within a vacuum chamber of a semiconductor manufacturing apparatus. The electrostatic chuck 100 includes a plate-like member 10 and a base member 20 arranged side by side in a predetermined arrangement direction (vertical direction (Z-axis direction) in this embodiment). The plate-like member 10 and the base member 20 are arranged so that the lower surface S2 (see FIG. 2) of the plate-like member 10 and the upper surface S3 of the base member 20 face each other in the arrangement direction with a joint portion 30 to be described later interposed therebetween. be done. That is, the base member 20 is arranged such that the upper surface S3 of the base member 20 is located on the lower surface S2 side of the plate-shaped member 10 .

The plate-like member 10 is a plate-like member having a substantially circular surface (hereinafter referred to as “attraction surface”) S1 that is substantially perpendicular to the arrangement direction (Z-axis direction) described above. aluminum nitride, etc.). The plate member 10 has a diameter of, for example, about 50 mm to 500 mm (usually about 200 mm to 350 mm), and a thickness of, for example, about 1 mm to 10 mm, preferably about 2 mm to 8 mm. It is preferably about 3 mm to 6 mm. The attraction surface S1 of the plate member 10 corresponds to the first surface in the claims, and the Z-axis direction corresponds to the first direction in the claims. Further, in this specification, the direction perpendicular to the Z-axis direction is referred to as the "plane direction", and as shown in FIG. The direction perpendicular to the circumferential direction CD is called the "radial direction RD".

As shown in FIG. 2, a chuck electrode 40 made of a conductive material (eg, tungsten, molybdenum, platinum, etc.) is arranged inside the plate member 10 . The shape of the chuck electrode 40 as viewed in the Z-axis direction is, for example, a substantially circular shape. When a voltage is applied to the chuck electrode 40 from a chucking power supply (not shown), an electrostatic attraction is generated, and the wafer W is attracted and fixed to the attraction surface S1 of the plate member 10 by this electrostatic attraction.

Further, as shown in FIG. 2, inside the plate-like member 10, a main heater electrode layer 60, a sub-heater electrode layer 50, a driver An electrode layer 70 is arranged. Each of the main heater electrode layer 60, the sub-heater electrode layer 50, and the driver electrode layer 70 is a layer of a conductive material extending in the plane direction. In the Z-axis direction (vertical direction), the positions of the main heater electrode layer 60, the sub-heater electrode layer 50, and the driver electrode layer 70 are different from each other. Specifically, in the Z-axis direction, the sub-heater electrode layer 50 is arranged below the chuck electrode 40 and above the main heater electrode layer 60 (closer to the adsorption surface S1). Also, the driver electrode layer 70 is arranged at a position between the sub-heater electrode layer 50 and the main heater electrode layer 60 in the Z-axis direction. In the Z-axis direction, the position where the main heater electrode layer 60 is arranged corresponds to the first position in the claims, and the position where the sub-heater electrode layer 50 is arranged corresponds to the second position in the claims. The position where the driver electrode layer 70 is arranged corresponds to the third position in the claims. These configurations will be described in detail later.

The base member 20 is, for example, a circular planar plate-like member having the same diameter as the plate-like member 10 or a larger diameter than the plate-like member 10, and is made of metal (aluminum, aluminum alloy, etc.), for example. The diameter of the base member 20 is, for example, approximately 220 mm to 550 mm (usually 220 mm to 350 mm), and the thickness of the base member 20 is, for example, approximately 20 mm to 40 mm.

The base member 20 is joined to the plate member 10 by a joining portion 30 arranged between the lower surface S2 of the plate member 10 and the upper surface S3 of the base member 20. As shown in FIG. The joint portion 30 is made of an adhesive such as silicone resin, acrylic resin, or epoxy resin. The thickness of the joint portion 30 is, for example, about 0.1 mm to 1 mm.

A coolant channel 21 is formed inside the base member 20 . When a coolant (for example, a fluorine-based inert liquid, water, or the like) is caused to flow through the coolant channel 21 , the base member 20 is cooled, and heat is transferred between the base member 20 and the plate-like member 10 via the joint portion 30 . The plate-like member 10 is cooled by (thermal drawing), and the wafer W held on the adsorption surface S1 of the plate-like member 10 is cooled. Thereby, control of the temperature distribution of the wafer W is realized.

A-2. Configuration of main heater electrode layer 60, sub-heater electrode layer 50, driver electrode layer 70, etc.:
Next, the structures of the main heater electrode layer 60, the sub-heater electrode layer 50, the driver electrode layer 70, and the like arranged on the plate member 10 will be described in detail. FIG. 4 is an explanatory diagram schematically showing the configuration of the main heater electrode layer 60, the sub-heater electrode layer 50, the driver electrode layer 70, and the like. FIG. 4 schematically shows the configuration of the main heater electrode layer 60, the sub-heater electrode layer 50, the driver electrode layer 70, etc., which are arranged on a part of the plate member 10. As shown in FIG.

Here, as shown in FIG. 3 , in the electrostatic chuck 100 of the present embodiment, main segments MSE, which are a plurality of virtual portions arranged in the plane direction (direction perpendicular to the Z-axis direction), are provided on the plate-like member 10 . (indicated by a dashed line in FIG. 3) is set. More specifically, when viewed in the Z-axis direction, the plate-like member 10 is divided into a plurality of virtual annular portions (however, Only the portion containing the center point CP is divided into circular portions), and each annular portion is a plurality of imaginary portions aligned in the circumferential direction CD by a plurality of second boundary lines BL2 extending in the radial direction RD. It is divided into main segments MSE. The number of main segments MSE is, for example, about 200-250.

As shown in FIG. 4, main heater electrode layer 60 includes a plurality of main heater electrodes 600 . Each of the plurality of main heater electrodes 600 included in the main heater electrode layer 60 is arranged in one of the plurality of main segments MSE set on the plate member 10 . That is, in the electrostatic chuck 100 of this embodiment, one main heater electrode 600 is arranged for each of the plurality of main segments MSE. In other words, the portion of the plate member 10 where one main heater electrode 600 is arranged (the portion mainly heated by the main heater electrode 600) becomes one main segment MSE. The boundary line between two main segments MSE adjacent to each other in the radial or circumferential direction when viewed in the Z-axis direction is the main heater electrode 600 arranged in one main segment MSE and the main heater electrode 600 arranged in the other main segment MSE. 600 is an intermediate position line.

FIG. 5 is an explanatory view schematically showing the XY cross-sectional configuration of one main heater electrode 600 arranged in one main segment MSE. 5 (and FIG. 6, which will be described later), the shape of the main segment MSE as viewed in the Z-axis direction is shown as a square for convenience, but it actually has the shape shown in FIG. As shown in FIG. 5, the main heater electrode 600 has a heater line portion 602, which is a linear resistance heating element as viewed in the Z-axis direction, and heater pad portions 604 connected to both ends of the heater line portion 602. . In this embodiment, the heater line portion 602 is shaped so as to pass through each position in the main segment MSE as evenly as possible when viewed in the Z-axis direction. The configuration of the main heater electrodes 600 arranged in other main segments MSE is the same.

Further, as shown in FIG. 4, in the electrostatic chuck 100 of the present embodiment, each main segment MSE of the plate-like member 10 is provided with sub-segments SSE, which are a plurality of virtual portions arranged in the planar direction. . More specifically, each main segment MSE of the plate-like member 10 is divided into sub-segments SSE, which are a plurality of virtual portions having substantially the same shape as viewed in the Z-axis direction. The number of sub-segments SSEs set in each main segment MSE is, for example, four. That is, the number of sub-segments SSE set in the entire plate-shaped member 10 is, for example, about 800 to 1,000 (=200 to 250×4). As an example, FIG. 4 schematically shows the YZ cross-sectional configuration of four sub-segments SSE (SSE1 to SSE4) set in one main segment MSE.

As shown in FIG. 4, the sub-heater electrode layer 50 includes multiple sub-heater electrodes 500 . Each of the plurality of sub-heater electrodes 500 included in the sub-heater electrode layer 50 is arranged in one of the plurality of sub-segments SSE set on the plate member 10 . That is, in the electrostatic chuck 100 of this embodiment, one sub-heater electrode 500 is arranged for each of the plurality of sub-segments SSE. In other words, the portion of the plate member 10 where one sub-heater electrode 500 is arranged (the portion mainly heated by the sub-heater electrode 500) becomes one sub-segment SSE. The boundary line between two sub-segments SSE that are adjacent to each other in the radial or circumferential direction when viewed in the Z-axis direction is the sub-heater electrode 500 arranged in one sub-segment SSE and the sub-heater electrode 500 arranged in the other sub-segment SSE. is the line at the middle position of .

FIG. 6 is an explanatory diagram schematically showing the XY cross-sectional configuration of the sub-heater electrodes 500 arranged in each of the four sub-segments SSE (SSE1 to SSE4) set in one main segment MSE. As shown in FIG. 6, each sub-heater electrode 500 has a heater line portion 502, which is a linear resistance heating element as viewed in the Z-axis direction, and heater pad portions 504 connected to both ends of the heater line portion 502. . The resistance of the resistance heating element forming the sub-heater electrode 500 is lower than the resistance of the resistance heating element forming the main heater electrode 600 . In this embodiment, the heater line portion 502 is shaped so as to pass through each position within the sub-segment SSE as evenly as possible when viewed in the Z-axis direction. It is preferable to make the plurality of sub-segments SSE belonging to the main segment MSE substantially identical in shape when viewed in the Z-axis direction, because the design of the sub-heater electrodes 500 arranged in each sub-segment SSE can be made common. The configuration of the sub-heater electrodes 500 arranged in each sub-segment SSE set in the other main segment MSE is the same. A set of sub-heater electrodes 500 arranged in each sub-segment SSE belonging to one main segment MSE is hereinafter referred to as a sub-heater electrode group 510 . In this embodiment, one sub-heater electrode group 510 is composed of four sub-heater electrodes 500 .

In addition, in the present embodiment, the sub-heater electrodes 500 arranged in each sub-segment SSE belonging to one main segment MSE have substantially the same heat generation amount per unit area as viewed in the Z-axis direction. In this specification, two values being "substantially the same" means that the larger value of the two values is 110% or less of the smaller value.

In this embodiment, as shown in FIG. 6, when viewed in the Z-axis direction, a portion of the outer circumference of the sub-segment SSE coincides with a portion of the outer circumference of the main segment MSE to which the sub-segment SSE belongs. but they don't necessarily have to match. For example, a part of the outer circumference of the sub-segment SSE is positioned outside the outer circumference of the main segment MSE to which the sub-segment SSE belongs by a predetermined amount (however, it does not exceed the outer circumference of the adjacent main segment MSE). You may have Conversely, a part of the outer circumference of the sub-segment SSE may be located inside the outer circumference of the main segment MSE to which the sub-segment SSE belongs by the predetermined amount.

Further, as shown in FIG. 4, the driver electrode layer 70 arranged on the plate member 10 has a plurality of driver electrodes 700 extending in the planar direction. In this embodiment, one driver electrode 700 is provided for each of the plurality of main segments MSE (the plurality of main heater electrodes 600). FIG. 7 is an explanatory diagram schematically showing the XY cross-sectional configuration of one driver electrode 700 provided for one main segment MSE. The driver electrode 700 is a pattern of a conductive material formed so as to overlap vias 81 and 83, which will be described later, when viewed in the Z-axis direction. The configuration of driver electrodes 700 provided for other main segments MSE is the same.

As shown in FIGS. 4, 5 and 7, the driver electrode 700 provided for one main segment MSE is electrically connected through vias 83 to the main heater electrode 600 arranged for the one main segment MSE. It is As shown in FIGS. 4, 6 and 7, each sub-heater electrode 500 arranged in each sub-segment SSE belonging to one main segment MSE (that is, a plurality of (four) electrodes constituting one sub-heater electrode group 510 ) sub-heater electrodes 500) are in parallel relation to each other. Also, the sub-heater electrode group 510 arranged in one main segment MSE is connected in series with the main heater electrode 600 arranged in one main segment MSE through vias 81, driver electrodes 700 and vias 83. It is connected.

Further, as shown in FIG. 2, the electrostatic chuck 100 is formed with a plurality of heater terminal holes Ht. Each heater terminal hole Ht includes a through hole penetrating the base member 20 from the upper surface S3 to the lower surface S4, a through hole penetrating the joint portion 30 in the vertical direction, and a concave portion formed on the lower surface S2 side of the plate member 10. and are integral holes formed by communicating with each other. At positions corresponding to the heater terminal holes Ht on the lower surface S2 of the plate-like member 10 (positions overlapping the heater terminal holes Ht when viewed in the Z-axis direction), one or more heater terminals made of a conductive material are provided. A power supply pad 88 is formed. As shown in FIGS. 2 and 4, the heater power supply pad 88 is electrically connected to the end of the main heater electrode 600 via the via 84 . Another heater power supply pad 88 is electrically connected to the end of the sub-heater electrode 500 through the via 82 .

Further, one or a plurality of heater terminal members 89 made of a conductive material are accommodated in each heater terminal hole Ht. Each heater terminal member 89 is joined to the heater power supply pad 88 by, for example, brazing. As a result, a certain heater terminal member 89 (hereinafter referred to as "first heater terminal member 89A") is electrically connected to the driver electrode 700 in the main heater electrode 600 via the heater power supply pad 88 and the via 84. It is electrically connected to the end opposite to the end to which it is electrically connected. Another heater terminal member 89 (hereinafter referred to as “second heater terminal member 89B”) is electrically connected to the driver electrode 700 in the sub-heater electrode 500 through the heater power supply pad 88 and the via 82. It is electrically connected to the end opposite to the connected end.

In such a configuration, as shown in FIG. 4, from the first heater terminal member 89A, heater power supply pads 88, vias 84, main heater electrodes 600, vias 83, driver electrodes 700, vias 81, sub-heater electrodes 500 are connected. , the via 82 and the heater power supply pad 88, an electric path EP is formed to reach the second heater terminal member 89B. In each main segment MSE, the electric path EP is formed for each sub-segment SSE (formed for each sub-heater electrode 500). That is, in this embodiment, four electric paths EP are formed in each main segment MSE.

When a voltage is applied to the main heater electrode 600 and the sub-heater electrode 500 from a heater power source (not shown) through the electric path EP, the main heater electrode 600 and the sub-heater electrode 500 generate heat. The heat generated by the main heater electrode 600 heats the main segment MSE on which the main heater electrode 600 is arranged, and the heat generated by the sub-heater electrode 500 heats the sub-segment SSE on which the sub-heater electrode 500 is arranged. Control of the temperature distribution of the surface S1 (and thus control of the temperature distribution of the wafer W held on the attraction surface S1 of the plate member 10) is realized.

In the present embodiment, since the main heater electrodes 600 are connected in parallel to the heater power source, the amount of heat generated by the main heater electrodes 600 is calculated for each main heater electrode 600 (that is, for each main segment MSE). can be controlled, and the control of the temperature distribution of the attraction surface S1 of the plate-like member 10 for each main segment MSE can be realized. Furthermore, in the present embodiment, since the sub-heater electrodes 500 are arranged in parallel in each main segment MSE, the amount of heat generated by the sub-heater electrodes 500 is controlled in units of each sub-heater electrode 500 (that is, in units of each sub-segment SSE). It is possible to control the temperature distribution of the attracting surface S1 of the plate-like member 10 in sub-segment SSE units (that is, control the temperature distribution in finer units that cannot be realized only by the main heater electrode 600). can be done.

The amount of heat generated by each sub-heater electrode 500 can be controlled by changing the voltage application time ratio for each sub-heater electrode 500 . For example, in the configuration shown in FIG. 4, if it is desired to lower the temperature of the sub-segment SSE4, the ratio of the voltage application time in the electric path EP passing through the sub-heater electrode 500 arranged in the sub-segment SSE4 should be reduced. Even if the ratio of the voltage application time in the electric path EP passing through the sub-heater electrode 500 arranged in the sub-segment SSE4 is set to zero, the main heater electrode 600 will generate heat due to the voltage application in the electric path EP passing through the other sub-heater electrodes 500. Therefore, the temperature of the subsegment SSE4 does not drop significantly, and the temperature can be finely adjusted for each subsegment SSE.

A-3. Effect of this embodiment:
As described above, the electrostatic chuck 100 of this embodiment includes the plate-like member 10 having the attraction surface S1 substantially perpendicular to the Z-axis direction, and at least a portion of the plate-like member 10 extending in a direction perpendicular to the Z-axis direction. a main heater electrode 600 that is arranged in each main segment MSE when virtually divided into a plurality of main segments MSE aligned (in the surface direction) and that is composed of a resistance heating element; A device for holding an object (for example, a wafer W) on S1. The electrostatic chuck 100 further includes a sub-heater electrode 500 arranged in each sub-segment SSE when each main segment MSE is virtually divided into a plurality of sub-segments SSE arranged in the plane direction, and each main heater electrode 600 A driver electrode 700 is provided and electrically connected to the main heater electrode 600 and the sub-heater electrode 500 . The electrostatic chuck 100 is further provided for each main heater electrode 600 and electrically connected to the end of the main heater electrode 600 opposite to the end electrically connected to the driver electrode 700 . A first heater terminal member 89A is provided for each sub-heater electrode 500 and is electrically connected to the end of the sub-heater electrode 500 opposite to the end electrically connected to the driver electrode 700. and a second heater terminal member 89B. Further, the sub-heater electrodes 500 forming a sub-heater electrode group 510, which is a set of sub-heater electrodes 500 arranged in each sub-segment SSE belonging to one main segment MSE, are in parallel with each other. Also, the sub-heater electrode group 510 arranged in one main segment MSE is connected in series via the driver electrode 700 to the main heater electrode 600 arranged in the one main segment MSE.

Thus, in the electrostatic chuck 100 of the present embodiment, each main segment MSE is virtually divided into a plurality of sub-segments SSE, and each sub-segment SSE is electrically connected to the second heater terminal member 89B. Connected sub-heater electrodes 500 are arranged in parallel relation to each other. Therefore, by individually controlling the power supply to each sub-heater electrode 500, it is possible to realize temperature control in sub-segment SSE units more finely than temperature control in main-segment MSE units. controllability of the temperature distribution of the adsorption surface S1 can be improved.

Also, in the electrostatic chuck 100 of the present embodiment, the sub-heater electrode group 510 is connected in series with the main heater electrode 600 . Therefore, compared to the configuration in which the electrostatic chuck 100 includes only the main heater electrode 600 (single layer) and the configuration in which the electrostatic chuck 100 includes only the sub-heater electrode 500 (single layer), the first heater terminal member 89A and the The resistance of the heater electrode between it and the second heater terminal member 89B can be increased. Therefore, according to the electrostatic chuck 100, when a predetermined voltage is applied, a desired wattage can be obtained without increasing the current flowing through each heater electrode, that is, without increasing the size of the power supply, cables, and the like. be able to.

The sub-heater electrodes arranged in the sub-segment SSE are configured by serially connecting a plurality of resistance heating elements having different positions in the Z-axis direction, thereby increasing the resistance of the sub-heater electrodes and allowing the current to flow to the sub-heater electrodes. It is also conceivable to reduce the current value. However, since the area of the sub-segment SSE as viewed in the Z-axis direction is relatively small, it is difficult to increase the resistance value of each resistance heating element that constitutes the sub-heater electrode in such a configuration. The thickness of the plate-like member 10 is increased due to the necessity of multilayering the heating element. If the thickness of the plate-like member 10 is too large, the heat mass increases, which slows down the heating/cooling rate, or the dielectric loss increases, making it difficult for the plasma to escape, which is not preferable.

In contrast, in the electrostatic chuck 100 of the present embodiment, the main heater electrode 600 arranged in the main segment MSE is connected in series to the sub-heater electrode group 510 to increase the resistance of the electric path EP. . Since each main segment MSE is virtually divided in the direction orthogonal to the Z-axis direction to form a plurality of sub-segments SSE, the main segment MSE has a larger area in the Z-axis direction view than the sub-segments SSE. Therefore, increasing the resistance of the main heater electrode 600 arranged in the main segment MSE can be easily realized. Therefore, according to the electrostatic chuck 100 of the present embodiment, compared to the case where one heater electrode is configured by connecting in series a plurality of resistance heating elements whose positions in the Z-axis direction are different for each sub-segment SSE. Therefore, it is possible to suppress the thickness of the plate member 10 from increasing.

As described above, according to the electrostatic chuck 100 of the present embodiment, temperature control is performed in units of sub-segments SSE, which is finer than temperature control in units of main segments MSE. While improving the controllability of the temperature distribution of the plate, compared to the case where one heater electrode is configured by connecting in series a plurality of resistance heating elements whose positions in the Z-axis direction are different for each sub-segment SSE The thickness of the shaped member 10 can be reduced, and compared to a configuration in which the electrostatic chuck 100 includes only a main heater electrode (one layer) and a configuration in which the electrostatic chuck 100 includes only a sub-heater electrode (one layer). , the resistance of the heater electrode between the first heater terminal member 89A and the second heater terminal member 89B can be increased.

In addition, in the electrostatic chuck 100 of the present embodiment, the sub-heater electrode 500 is composed of a resistance heating element having a resistance lower than that of the resistance heating element that constitutes the main heater electrode 600 . Therefore, according to the electrostatic chuck 100 of the present embodiment, the resistance of the heater electrode between the first heater terminal member 89A and the second heater terminal member 89B can be effectively increased.

Further, in the electrostatic chuck 100 of the present embodiment, the amounts of heat generated per unit area in the Z-axis direction of the sub-heater electrodes 500 arranged in the sub-segments SSE belonging to one main segment MSE are substantially equal to each other. are identical. Therefore, according to the electrostatic chuck 100 of the present embodiment, highly accurate temperature control can be realized for each sub-segment SSE, and the controllability of the temperature distribution of the attraction surface S1 of the plate member 10 can be effectively improved. can be improved.

In addition, in the electrostatic chuck 100 of the present embodiment, the sub-heater electrode layer 50 is arranged above the position of the main heater electrode layer 60 (closer to the adsorption surface S1) in the Z-axis direction. That is, in the Z-axis direction, the sub-heater electrode 500 is arranged above the position of the main heater electrode 600 (closer to the attraction surface S1). Thus, in the electrostatic chuck 100 of the present embodiment, the sub-heater electrodes 500 arranged in the sub-segments SSE that are more subdivided than the main segments MSE are replaced by the main heater electrodes 600 arranged in the main segments MSE. Since the sub-heater electrode 500 is arranged closer to the attraction surface S1, temperature control is performed for each sub-segment SSE by switching the power supply to the sub-heater electrode 500, thereby further improving the controllability of the temperature distribution of the attraction surface S1 of the plate member 10. can be substantially improved.

In addition, in the electrostatic chuck 100 of the present embodiment, the positions of the main heater electrode layer 60, the sub-heater electrode layer 50, and the driver electrode layer 70 are different from each other in the Z-axis direction. That is, the positions of the main heater electrode 600, the sub-heater electrode 500, and the driver electrode 700 are different from each other in the Z-axis direction. Thus, in the electrostatic chuck 100 of the present embodiment, the driver electrode 700 is arranged at a position different from the positions of the main heater electrode 600 and the sub-heater electrode 500 in the Z-axis direction. Therefore, compared to a configuration in which the driver electrodes 700 are arranged at the same positions as the main heater electrodes 600 or the sub-heater electrodes 500 in the Z-axis direction, the degree of freedom in setting the pattern of the driver electrodes 700 is improved. The degree of freedom in pattern setting of the heater electrode 600 and the sub-heater electrode 500 is also improved. Therefore, according to the electrostatic chuck 100 of the present embodiment, a more suitable pattern of the main heater electrode 600 and the sub-heater electrode 500 can be realized, so that the controllability of the temperature distribution of the attraction surface S1 of the plate member 10 can be more effectively controlled. can be improved to

B. Variant:
The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified in various forms without departing from the scope of the invention. For example, the following modifications are possible.

The configuration of the electrostatic chuck 100 in the above embodiment is merely an example, and various modifications are possible. For example, in the above embodiments, the shapes of the main heater electrode 600 and the sub-heater electrode 500 are merely examples, and can be changed to any shape.

Also, the manner of setting the main segments MSE (the number of main segments MSE, the shape of each main segment MSE, etc.) in the above embodiment can be arbitrarily changed. For example, in the above embodiment, a plurality of main segments MSE are set so that each main segment MSE is arranged in the circumferential direction CD of the attraction surface S1. A segment MSE may be configured. Further, for example, in the above embodiment, the entire electrostatic chuck 100 is virtually divided into a plurality of main segments MSE, but a portion of the electrostatic chuck 100 is virtually divided into a plurality of main segments MSE. may

Similarly, the manner of setting the sub-segments SSE (the number of sub-segments SSE per one main segment MSE, the shape of each individual sub-segment SSE, etc.) in the above embodiment can be arbitrarily changed. For example, in the above embodiment, each main segment MSE is virtually divided into four sub-segments SSE, but the number of divisions into sub-segments SSE in each main segment MSE can be changed arbitrarily.

In the above embodiment, the sub-heater electrode 500 is arranged above the main heater electrode 600 (closer to the attraction surface S1) than the main heater electrode 600 in the Z-axis direction, but the sub-heater electrode 500 is arranged below the main heater electrode 600. It may be arranged (on the side far from the attraction surface S1). In the above embodiment, the driver electrode 700 is arranged at a different position from the sub-heater electrode 500 and the main heater electrode 600 in the Z-axis direction. position. In the above-described embodiment, the sub-heater electrode 500 is composed of a resistance heating element having a resistance lower than that of the resistance heating element that constitutes the main heater electrode 600. relationship does not have to be

In the above embodiment, the via 82 extending downward from the sub-heater electrode 500 is directly connected to the second heater terminal member 89B. The degree of freedom of the second heater terminal member 89B may be improved by arranging the driver electrodes extending in the plane direction. Further, the second heater terminal members 89B may be collectively arranged in one heater terminal hole Ht for each main segment MSE. may be arranged in one heater terminal hole Ht.

In addition, as described above, in the electrostatic chuck 100 of the present embodiment, when different voltages are applied to the second heater terminal members 89B, each sub-heater electrode 500 unit (that is, each sub-segment SSE unit) However, if the same voltage is applied to each second heater terminal member 89B, the temperature distribution can be controlled for each main heater electrode 600 (that is, for each main segment MSE). ) temperature distribution control can be realized.

Further, in the above embodiments, each via may be composed of a single via, or may be composed of a group of multiple vias. In the above embodiments, each via may have a single-layer structure consisting only of a via portion, or may have a multi-layer structure (for example, a structure in which a via portion, a pad portion, and a via portion are laminated). good too. Further, in the above-described embodiment, a monopolar system in which one chuck electrode 40 is provided inside the plate-like member 10 is adopted. method may be employed.

Further, the material for forming each member (the plate member 10, the base member 20, the joint portion 30, the sub-heater electrode layer 50, the main heater electrode layer 60, the driver electrode layer 70, etc.) of the electrostatic chuck 100 of the above embodiment is strictly This is an example, and various modifications are possible. For example, in the above-described embodiment, the electrostatic chuck 100 includes the plate member 10 made of ceramics, but instead of the plate member 10, the electrostatic chuck 100 uses a material other than ceramics (for example, resin material).

Further, the present invention is not limited to the electrostatic chuck 100 that includes the plate-like member 10 and the base member 20 and holds the wafer W using electrostatic attraction. It is also applicable to other holding devices (for example, heater devices such as CVD heaters, vacuum chucks, etc.) that hold an object on the surface of the plate-like member 10.

10: Plate-shaped member 20: Base member 21: Coolant flow path 30: Joint 40: Chuck electrode 50: Sub-heater electrode layer 60: Main heater electrode layer 70: Driver electrode layer 81: Via 82: Via 83: Via 84: Via 88: Heater power supply pad 89: Heater terminal member 100: Electrostatic chuck 500: Sub-heater electrode 502: Heater line section 504: Heater pad section 600: Main heater electrode 602: Heater line section 604: Heater pad section 700: Driver electrode BL1: First boundary line BL2: Second boundary line CD: Circumferential direction CP: Center point EP: Electric path Ht: Heater terminal hole MSE: Main segment RD: Radial direction S1: Attraction surface S2: Lower surface S3: Upper surface S4: Lower surface SSE: Subsegment W: Wafer

Claims (5)

a plate-like member having a first surface substantially perpendicular to the first direction;
A main heater composed of a resistance heating element and arranged in each main segment when at least part of the plate member is virtually divided into a plurality of main segments arranged in a direction perpendicular to the first direction. an electrode;
A holding device for holding an object on the first surface of the plate member, further comprising:
sub-heater electrodes arranged in each sub-segment obtained by virtually dividing each main segment into a plurality of sub-segments arranged in a direction perpendicular to the first direction;
a driver electrode provided for each of the main heater electrodes and electrically connected to the main heater electrode and the sub-heater electrode;
a first terminal member provided for each of the main heater electrodes and electrically connected to an end of the main heater electrode opposite to the end electrically connected to the driver electrode;
a second terminal member provided for each of the sub-heater electrodes and electrically connected to an end of the sub-heater electrode opposite to the end electrically connected to the driver electrode;
with
A plurality of the sub-heater electrodes constituting a sub-heater electrode group, which is a set of the sub-heater electrodes arranged in each of the sub-segments belonging to one of the main segments, are arranged in parallel with each other so that power supply can be individually controlled. can be,
the group of sub-heater electrodes arranged in one of the main segments are connected in series with the main heater electrodes arranged in one of the main segments via the driver electrodes ,
The holding device , wherein in one of the main segments, the sub-heater electrode group and the main heater electrode are arranged at positions different from each other in the first direction. A holding device according to claim 1, wherein
The plurality of sub-heater electrodes constituting the group of sub-heater electrodes arranged in the one main segment generate resistance heat having a resistance lower than that of the resistance heating element constituting the main heater electrode arranged in the one main segment. made up of the body
A holding device characterized by: In the holding device according to claim 1 or claim 2,
The amounts of heat generated per unit area of each of the sub-heater electrodes arranged in each of the sub-segments belonging to one of the main segments are substantially the same as each other when viewed in the first direction.
A holding device characterized by: In the holding device according to any one of claims 1 to 3,
each of the main heater electrodes is arranged at a first position in the first direction;
each said sub-heater electrode is disposed at a second position closer to said first surface than said first position in said first direction;
A holding device characterized by: In the holding device according to any one of claims 1 to 4,
each of the main heater electrodes is arranged at a first position in the first direction;
each of the sub-heater electrodes is arranged at a second position different from the first position in the first direction;
each said driver electrode is arranged in said first direction at a third position different from said first position and said second position;
A holding device characterized by:

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