Electrostatic chuck

Abstract

To provide an electrostatic chuck capable of ensuring a sufficient amount of heat generation of a heater.SOLUTION: An electrostatic chuck 10 includes a dielectric substrate 100, and a heater unit 300 that heats the dielectric substrate 100. The dielectric substrate 100 has a first region HB1 and a second region HB2 adjacent to each other in a top view. The heater unit 300 includes a first heater 610 arranged at a position corresponding to the first region HB1, and a second heater 620 arranged at a position corresponding to the second region HB2. The first heater 610 and the second heater 620 each include a heat generating portion (611, 621, 622) which is a conductor that is linearly laid. The line width of the heat generating portions 621, 622 in the second heater 620 is narrower than the line width of the heat generating portion 611 in the first heater 610. The second heater 620 includes a plurality of heat generating portions 621, 622 connected in parallel to each other.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to an electrostatic chuck. [Background technology]

[0002] For example, in semiconductor manufacturing equipment such as an etching device, an electrostatic chuck is provided as a device for attracting and holding a substrate such as a silicon wafer to be processed. The electrostatic chuck has a dielectric substrate on which an attracting electrode is provided. When a voltage is applied to the attracting electrode, an electrostatic force is generated, and the substrate placed on the dielectric substrate is attracted and held.

[0003] When a substrate is processed in a semiconductor manufacturing device, it is necessary to adjust the temperature so that the temperature distribution within the surface of the substrate is as uniform as possible. In order to enable high-precision temperature adjustment, electrostatic chucks equipped with heaters have been developed in recent years and have already been put to practical use. The heater may be provided inside the dielectric substrate, or may be provided as a unit between the dielectric substrate and the base plate, as described in Patent Document 1 below. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-197485 Summary of the Invention [Problem to be solved by the invention]

[0005] The heater has a heat generating portion which is a conductor wired in a linear shape. When power is supplied from the outside and a current flows through the heat generating portion, Joule heat is generated in the heat generating portion. In order to make it possible to individually adjust the temperature of each portion of the dielectric substrate, the heat generating portion of the heater is wired individually in each of the multiple regions.

[0006] Among the multiple regions, there are some regions where it is difficult to ensure that the line width of the heating part is the same as that of other regions, for example, because it is necessary to route the heating part while avoiding interference with through holes formed in the dielectric substrate. In such regions, the line width of the heating part narrows while the length increases, resulting in a problem of increased electrical resistance of the heating part and reduced heat generation.

[0007] The present invention has been made in view of the above problems, and has an object to provide an electrostatic chuck that can ensure a sufficient amount of heat generation from a heater. [Means for solving the problem]

[0008] In order to solve the above problems, an electrostatic chuck according to the present invention includes a dielectric substrate having a mounting surface on which an object to be attracted is placed, and a heater for heating the dielectric substrate. The dielectric substrate has a first region and a second region adjacent to each other when viewed from a direction perpendicular to the mounting surface. The heater includes a first heater disposed at a position corresponding to the first region, and a second heater disposed at a position corresponding to the second region. Both the first heater and the second heater include a heat generating portion which is a conductor that is wired. The line width of the heat generating portion in the second heater is narrower than the line width of the heat generating portion in the first heater. The second heater includes a plurality of heat generating portions connected in parallel to each other.

[0009] In the electrostatic chuck having such a configuration, the heater includes a first heater disposed at a position corresponding to the first region of the dielectric substrate, and a second heater disposed at a position corresponding to the second region of the dielectric substrate. The second heater has a narrower line width of the heat generating portion than the first heater. Therefore, as the "second region" of the dielectric substrate, for example, a relatively complicated region having a through hole or the like formed therein may be selected.

[0010] In the electrostatic chuck, the heat generating portion of the second heater has a narrower line width than the heat generating portion of the first heater, but includes a plurality of heat generating portions connected in parallel to each other. Therefore, the length of each heat generating portion of the second heater can be made shorter than when the entire heater is composed of only one heat generating portion. This makes it possible to ensure that the heat generating portion of the second heater generates the same amount of heat as the heat generating portion of the first heater. Effect of the Invention

[0011] According to the present invention, it is possible to provide an electrostatic chuck capable of ensuring a sufficient amount of heat generation from a heater. [Brief description of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view illustrating a schematic configuration of an electrostatic chuck according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded view showing a schematic configuration of a heater unit. [Diagram 3] 5A to 5C are diagrams illustrating examples of arrangement of sub-heater layers in a heater unit. [Figure 4] FIG. 1 is a diagram showing the configuration of one sub-heater layer. [Diagram 5] 5A to 5C are diagrams showing examples of the arrangement of main heater layers in a heater unit. [Figure 6] FIG. 2 is a diagram showing the configuration of a main heater layer. [Figure 7] 6A to 6C are diagrams illustrating examples of the arrangement of first heat generating portions and second heat generating portions in a second region. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components in each drawing are denoted by the same reference numerals as much as possible, and duplicated description will be omitted.

[0014] The electrostatic chuck 10 according to this embodiment is configured to electrostatically attract and hold a substrate W to be processed inside a semiconductor manufacturing apparatus (not shown), such as an etching apparatus. The substrate W to be attracted is, for example, a silicon wafer. The electrostatic chuck 10 may be used in an apparatus other than a semiconductor manufacturing apparatus.

[0015] 1 shows, in a schematic cross-sectional view, the configuration of an electrostatic chuck 10 in a state in which the electrostatic chuck 10 attracts and holds a substrate W. The electrostatic chuck 10 includes a dielectric substrate 100, a base plate 200, and a heater unit 300.

[0016] The dielectric substrate 100 is a substantially disk-shaped member made of a sintered ceramic body. The dielectric substrate 100 contains, for example, high-purity aluminum oxide (Al2O3), but may contain other materials. The purity, type, and additives of the ceramics in the dielectric substrate 100 can be appropriately set in consideration of the plasma resistance and other properties required of the dielectric substrate 100 in semiconductor manufacturing equipment.

[0017] 1 of the dielectric substrate 100 is a "mounting surface" on which the substrate W is mounted. Also, a lower surface 120 of the dielectric substrate 100 in FIG. 1 is a "bonded surface" that is bonded to the heater unit 300 via a bonding layer 410. The viewpoint when the electrostatic chuck 10 is viewed from the side of the surface 110 along a direction perpendicular to the surface 110 will hereinafter be referred to as a "top view".

[0018] An adsorption electrode 130 is embedded inside the dielectric substrate 100. The adsorption electrode 130 is a thin flat layer made of a metal material such as tungsten, and is arranged parallel to the surface 110. The material of the adsorption electrode 130 may be molybdenum, platinum, palladium, or the like, in addition to tungsten. When a voltage is applied to the adsorption electrode 130 from the outside via a power supply path (not shown), an electrostatic force is generated between the surface 110 and the substrate W, thereby adsorbing and holding the substrate W. As the configuration of the power supply path, various known configurations can be adopted. The adsorption electrode 130 may be provided as a so-called "monopolar" electrode as in this embodiment, or may be provided as two so-called "bipolar" electrodes.

[0019] As shown in Fig. 1, a space SP is formed between the dielectric substrate 100 and the substrate W. When a process such as film formation is performed in the semiconductor manufacturing apparatus, helium gas for temperature adjustment is supplied from the outside to the space SP through a gas hole (not shown). By providing helium gas between the dielectric substrate 100 and the substrate W, the thermal resistance between them is adjusted, and the temperature of the substrate W is thereby maintained at an appropriate temperature. The gas for temperature adjustment supplied to the space SP may be a type of gas other than helium.

[0020] A seal ring 111 and dots 112 are provided on a surface 110 serving as a mounting surface, and the above-mentioned space SP is formed around these.

[0021] The seal ring 111 is a wall that divides the space SP at the outermost position. The seal ring 111 forms part of the surface 110 and abuts against the substrate W. A plurality of seal rings 111 may be provided to divide the space SP. With this configuration, it is possible to individually adjust the pressure of the helium gas in each space SP and make the surface temperature distribution of the substrate W during processing more uniform.

[0022] 1, the portion marked with the reference symbol "116" is the bottom surface of the space SP. Hereinafter, this portion will also be referred to as the "bottom surface 116." The seal ring 111, together with the dots 112 described below, is formed by digging down a part of the surface 110 to the position of the bottom surface 116.

[0023] The dots 112 are circular protrusions protruding from the bottom surface 116. A plurality of dots 112 are provided and are distributed approximately evenly on the mounting surface of the dielectric substrate 100. The upper end of each dot 112 forms part of the surface 110 and abuts against the substrate W. By providing a plurality of such dots 112, bending of the substrate W is suppressed.

[0024] Lift pin holes LH are formed in the electrostatic chuck 10, but are omitted in FIG. 1 (see FIG. 5). The lift pin holes LH are through holes for inserting lift pins (not shown) provided in a semiconductor manufacturing device. The lift pin holes LH are formed so as to linearly penetrate the entire electrostatic chuck 10 including the dielectric substrate 100 along a direction perpendicular to the surface 110, which is the mounting surface (the vertical direction in FIG. 1). That is, the lift pin holes LH are formed so as to penetrate each of the dielectric substrate 100, the base plate 200, and the heater unit 300. A total of three lift pin holes LH are formed, and are arranged so as to be equally spaced at 120 degrees from each other when viewed from above. The lift pins that move up and down through the lift pin holes LH attach and detach the substrate W to and from the surface 110 of the dielectric substrate 100.

[0025] The base plate 200 is a substantially disk-shaped member that supports the dielectric substrate 100 and the heater unit 300. The base plate 200 is formed of a metal material such as aluminum. The upper surface 210 of the base plate 200 in FIG. 1 is a "bonded surface" that is bonded to the heater unit 300 via a bonding layer 420.

[0026] A coolant flow path 250 for flowing a coolant is formed inside the base plate 200. When a process such as film formation is performed in the semiconductor manufacturing apparatus, a coolant is supplied to the coolant flow path 250 from the outside, thereby cooling the base plate 200. Heat generated in the substrate W during the process is transferred to the coolant via the helium gas in the space SP, the dielectric substrate 100, and the base plate 200, and is discharged to the outside together with the coolant.

[0027] An insulating film may be formed on the surface of the base plate 200. For example, an alumina film formed by thermal spraying can be used as the insulating film. By covering the surface of the base plate 200 with the insulating film, the dielectric strength of the base plate 200 can be increased.

[0028] The heater unit 300 generates heat when power is supplied from an external source, and heats the dielectric substrate 100. As will be described later, the heater unit 300 is provided with a plurality of heat generating parts 331, etc., and the amount of heat generated by each of the heat generating parts 331, etc. can be individually adjusted. By individually adjusting the amount of heat generated by each part, the in-plane temperature distribution of the substrate W during processing can be made closer to uniform.

[0029] The heater unit 300 is sandwiched between the dielectric substrate 100 and the base plate 200 and is bonded to each of them. The heater unit 300 and the dielectric substrate 100 are bonded via a bonding layer 410, and the heater unit 300 and the base plate 200 are bonded via a bonding layer 420. The bonding layers 410 and 420 are layers formed by, for example, hardening a silicone adhesive. A plurality of particulate fillers (fillers) for increasing thermal conductivity are disposed inside each of the bonding layers. For example, particles mainly composed of alumina can be used as the filler.

[0030] A specific configuration of the heater unit 300 will be described. In FIG. 2, the configuration of the heater unit 300 is shown as a schematic exploded view. As shown in the figure, the heater unit 300 has a support plate 310 (310A), an insulating layer 320, a sub-heater layer 330, an insulating layer 340, a main heater layer 600, an insulating layer 360, a bypass layer 370, an insulating layer 380, a support plate 310 (310B), and a power supply section 390. In this embodiment, the sub-heater layer 330, the main heater layer 600, and the bypass layer 370 are arranged in this order from the top, but the arrangement order of these may be different from that of this embodiment.

[0031] The support plate 310 is a substantially disk-shaped member, and is provided at each of the upper and lower ends of the heater unit 300 in FIG. 2. The support plate 310 provided at the upper end in FIG. 2 is also referred to as "support plate 310A" below. The support plate 310 provided at the lower end in FIG. 2 is also referred to as "support plate 310B" below. The support plate 310A is a portion bonded to the dielectric substrate 100 via a bonding layer 410, and the support plate 310B is a portion bonded to the base plate 200 via a bonding layer 420.

[0032] The pair of support plates 310A, 310B are members for reinforcing the entire heater unit 300 by sandwiching the entire sub-heater layer 330, the main heater layer 600, the bypass layer 370, etc. between them. In this embodiment, both the support plates 310A, 310B are made of metal, but they may be made of other materials (e.g., insulating materials). Note that, although a plurality of through holes are formed in each of the members constituting the heater unit 300, such as the support plate 310, for the purpose of passing lift pins through, etc., they are not shown in FIG. 2.

[0033] The insulating layer 320 is provided between the support plate 310A and the sub-heater layer 330, and serves to electrically insulate them from each other. The insulating layer 320 also serves to physically bond them together. In this embodiment, the insulating layer 320 is a polyimide film, but it may be made of other materials. If the support plate 310A is made of an insulating material, it is possible to eliminate the insulating layer 320.

[0034] The sub-heater layer 330 is a part that generates heat when power is supplied from the outside. In Fig. 2, the sub-heater layer 330 is depicted as a single disk, but in reality, the sub-heater layer 330 is divided into a plurality of regions, and each region can be individually heated. The specific configuration of the sub-heater layer 330 will be described later.

[0035] The insulating layer 340 is provided between the sub-heater layer 330 and the main heater layer 600, and serves to electrically insulate the two layers from each other. The insulating layer 340 also serves to physically bond the two layers together. In this embodiment, the insulating layer 340 is a polyimide film, but it may be made of other materials.

[0036] The main heater layer 600, like the sub-heater layer 330 described above, is a part that receives power from an external source and generates heat. In Fig. 2, the main heater layer 600 is depicted as a single disk, but in reality, the main heater layer 600 is divided into a plurality of regions, and each region can be individually heated. The specific configuration of the main heater layer 600 will be described later.

[0037] The main heater layer 600 has a larger heat generation amount than the sub-heater layer 330 described above. The main heater layer 600 is intended to increase the temperature of the entire dielectric substrate 100 in a short time. The sub-heater layer 330 is intended to adjust the temperature of each part of the dielectric substrate 100 and make the in-plane temperature distribution of the substrate W closer to uniform. In this manner, in this embodiment, two heater layers are provided separately according to their respective roles. Alternatively, a configuration may be adopted in which only the main heater layer 600 is provided and the sub-heater layer 330 is not provided.

[0038] The insulating layer 360 is provided between the main heater layer 600 and the bypass layer 370, and serves to electrically insulate the two layers from each other. The insulating layer 360 also serves to physically bond the two layers together. In this embodiment, the insulating layer 360 is a polyimide film, but it may be made of other materials.

[0039] The bypass layer 370 is a layer for electrically connecting the power supply unit 390, which will be described later, to the sub-heater layer 330 and the main heater layer 600. In FIG. 2, the bypass layer 370 is depicted as a single disk, but in reality, the bypass layer 370 is divided into a plurality of layers. By providing the bypass layer 370 in the middle of each electric path connecting the power supply unit 390 to the sub-heater layer 330 or the main heater layer 600, it becomes possible to adjust the position of the power supply unit 390, etc. Each of the divided bypass layers 370 has a portion welded to the sub-heater layer 330 or the main heater layer 600.

[0040] The insulating layer 380 is provided between the bypass layer 370 and the support plate 310B, and serves to electrically insulate the two. The insulating layer 380 also serves to physically bond the two. In this embodiment, the insulating layer 380 is a polyimide film, but it may be made of other materials. If the support plate 310B is made of an insulating material, it is possible to eliminate the insulating layer 380.

[0041] 2 are laminated, the entire assembly is pressurized and heated, and the entire assembly is bonded together via the insulating layer 320, which is a polyimide film, and the like.

[0042] The power supply unit 390 is a part that receives, from the outside, the power required to heat the sub-heater layer 330 and the like. In this embodiment, the power supply unit 390 is formed as a long, thin rod-shaped plug, one end of which is connected to the bypass layer 370. A plurality of power supply units 390 are provided according to the number of bypass layers 370, but only two of them are shown in FIG. 2. Through holes (not shown) are formed in the base plate 200 at positions corresponding to the power supply units 390, and the power supply units 390 are inserted through the through holes.

[0043] Instead of the above configuration, each power supply section 390 may be directly connected to either the sub-heater layer 330 or the main heater layer 600 without passing through the bypass layer 370 .

[0044] The structure of the sub-heater layer 330 will be described. The sub-heater layer 330 is divided into a plurality of regions when viewed from above, and each region can generate heat individually. From another perspective, it can also be said that the dielectric substrate 100 has a plurality of regions when viewed from above, and one of the divided sub-heater layers 330 is disposed in an area directly below each of the regions. In other words, each of the divided sub-heater layers 330 is disposed in a position corresponding to each region of the dielectric substrate 100 (a position where they overlap when viewed from above).

[0045] 3 shows, in top view, an example of how the dielectric substrate 100 is divided to correspond to the sub-heater layer 330. In this example, the dielectric substrate 100 is divided into a total of 24 regions HA. The sub-heater layer 330 is also divided into a total of 24 regions in the same manner, and is individually disposed directly below each region HA in FIG.

[0046] The sub-heater layer 330 includes a heat generating portion 331 which is a conductor drawn in a linear shape. Joule heat is generated in the heat generating portion 331 by the flow of an externally supplied current. The heat generating portion 331 is drawn individually in each range overlapping with each region HA in top view. FIG. 4 shows an example of a heat generating portion 331 drawn in a range overlapping with one region HA. In each region HA, one linear heat generating portion 331 is drawn in a path that passes evenly through almost the entire range.

[0047] Circular pad portions 333, 334 are formed on both ends of the heat generating portion 331. The heat generating portion 331 and the pad portions 333, 334 are formed, for example, by etching a thin metal foil, and the whole functions as one sub-heater layer 330. The bypass layer 370 is connected to the pad portions 333, 334 by welding or the like. Therefore, the pad portions 333, 334 serve as inlets and outlets for current. In other regions HA as well, the heat generating portion 331 is routed in the same manner as in FIG. 4.

[0048] The configuration of the main heater layer 600 will be described. Like the sub-heater layer 330, the main heater layer 600 is also divided into a plurality of regions, and each region can be made to generate heat individually. From another perspective, it can also be said that the dielectric substrate 100 has a plurality of regions in a top view, and one of the divided main heater layers 600 is disposed in an area directly below each of the regions. In other words, each of the divided main heater layers 600 is disposed in a position corresponding to each region of the dielectric substrate 100 (a position where they overlap in a top view).

[0049] The manner in which the dielectric substrate 100 is divided into regions corresponding to the main heater layer 600 is different from the manner in which the dielectric substrate 100 is divided into regions corresponding to the sub-heater layer 330 (FIG. 3).

[0050] 5 shows an example of how to divide the dielectric substrate 100 corresponding to the main heater layer 600 from a top view. In this example, the dielectric substrate 100 is divided into a total of two regions HB. The main heater layer 600 is also divided into a total of two in the same manner, and is individually disposed directly below each region HB in FIG. 5.

[0051] Of the two regions HB of the dielectric substrate 100, one region HB is also referred to as the "first region HB1" below. The other region HB is also referred to as the "second region HB2" below. The first region HB1 and the second region HB2 are adjacent to each other in a top view.

[0052] The first region HB1 is a circular region including the center of the dielectric substrate 100 when viewed from above. The center of the first region HB1 coincides with the center of the dielectric substrate 100 when viewed from above.

[0053] The second region HB2 is an annular region surrounding the first region HB1 from the outside all around in a top view, and includes the portion where the lift pin hole LH is formed in a top view.

[0054] 6 shows the overall configuration of the main heater layer 600 in top view. The main heater layer 600 includes a first heater 610 and a second heater 620 that are separated from each other. The first heater 610 is provided at a position corresponding to the first region HB1 (a position overlapping in top view), and the second heater 620 is provided at a position corresponding to the second region HB2 (a position overlapping in top view).

[0055] The first heater 610 includes a heat generating portion 611 which is a conductor drawn in a linear shape. The heat generating portion 611 is drawn in a path that passes through substantially the entire range overlapping with the first region HB1 in a top view. The line width of the heat generating portion 611 is generally uniform throughout.

[0056] Within a range overlapping with the first region HB1 in top view, a pair of pad portions 613 and 614 are provided. One end of the heat generating portion 611 is connected to the pad portion 613, and the other end is connected to the pad portion 614.

[0057] In the range overlapping with the first region HB1 in top view, only one pair of pad portions 613, 614 is provided. Also, only one heat generating portion 611 connects between the pad portion 613 and the pad portion 614.

[0058] The heat generating portion 611 and the pad portions 613, 614 are formed, for example, by etching a thin metal foil, and the whole portion functions as one first heater 610. The bypass layer 370 is connected to the pad portions 613, 614 by welding or the like. Therefore, the pad portions 613, 614 serve as an inlet and outlet for current. Current supplied from one of the pad portions 613, 614 passes through the heat generating portion 611 and generates Joule heat.

[0059] No lift pin holes LH are formed in the first region HB1. When routing the heat generating portion 611 in the first region HB1, there is no need to avoid interference with the lift pin holes LH, so the heat generating portion 611 is routed along a relatively simple path.

[0060] The second heater 620 includes heat generating parts 621 and 622, which are conductors drawn in a linear shape. The heat generating parts 621 and 622 are drawn in a path that passes through almost the entire range overlapping with the second region HB2 in a top view. The line width of the heat generating parts 621 and 622 is generally uniform throughout.

[0061] A pair of pad portions 623, 624 are provided within a range overlapping with the second region HB2 in top view. One end of the heat generating portion 621 is connected to the pad portion 623, and the other end is connected to the pad portion 624. Similarly, one end of the heat generating portion 622 is connected to the pad portion 623, and the other end is connected to the pad portion 624.

[0062] Only one pair of pad portions 623, 624 is provided within the range overlapping with the second region HB2 in top view. Pad portion 623 and pad portion 624 are connected by heat generating portion 621 and also by heat generating portion 622. In other words, pad portion 623 and pad portion 624 are connected by heat generating portion 621 and heat generating portion 622 which are parallel to each other. Heat generating portion 621 corresponds to the "first heat generating portion" in this embodiment. Heat generating portion 622 corresponds to the "second heat generating portion" in this embodiment. The entire length of heat generating portion 621 is approximately equal to the entire length of heat generating portion 622.

[0063] The heat generating portions 621, 622 and the pad portions 623, 624 are formed, for example, by etching a thin metal foil, and the whole portion functions as one second heater 620. The bypass layer 370 is connected to the pad portions 623, 624 by welding or the like. Therefore, the pad portions 623, 624 serve as an inlet and outlet for current. A current supplied from one of the pad portions 623, 624 passes through each of the heat generating portions 621, 622, and generates Joule heat in each of them.

[0064] The lift pin hole LH is formed in the second region HB2. When the heat generating parts 621 and 622 are routed in the second region HB2, it is necessary to avoid interference with the lift pin hole LH, so the heat generating parts 621 and 622 are routed in a relatively complicated path. For this reason, if the line width of the heat generating parts 621 and 622 is made as thick as the line width of the heat generating part 611, it becomes difficult to route the heat generating part 621 and the like over the entire second region HB2. Therefore, in this embodiment, the line width of the heat generating parts 621 and 622 is made narrower than the line width of the heat generating part 611. This makes it possible to route the heat generating part 621 and the like over the entire second region HB2 while avoiding interference with the lift pin hole LH.

[0065] It is also possible to configure the pad portion 623 and the pad portion 624 to be connected by only one heat generating portion 621. In that case, however, in the second region HB2, the line width of the heat generating portion 621 needs to be narrowed as described above, so the overall length of the heat generating portion 621 becomes long. As a result, the electrical resistance of the heat generating portion 621 increases, causing a problem that the amount of heat generated becomes small.

[0066] Therefore, in this embodiment, as described above, the pad portion 623 and the pad portion 624 are connected by two heat generating portions 621, 622 connected in parallel to each other. With this configuration, the length of each of the heat generating portions 621, 622 can be shortened, and the electrical resistance of each can be suppressed. As a result, it is possible to ensure that the heat generating portions 621, 622 of the second heater 620 generate the same amount of heat as the heat generating portion 611 of the first heater 610.

[0067] In the second heater 620, the number of heat generating parts connected in parallel to each other may be two as in this embodiment, but may also be three or more.

[0068] The specific arrangement of the heat generating parts 621, 622 included in the second heater 620 is not limited to the example shown in Fig. 6, and various arrangements are possible. For example, as shown in Fig. 7(A), the second region HB2 may be divided into an outer peripheral region HB21 and an inner peripheral region HB22, and the entire heat generating part 621 may be arranged in the region HB21, and the entire heat generating part 622 may be arranged in the region HB22. In the example of Fig. 7(A), the radial range in which the heat generating part 621 is routed (arrow AR11) and the radial range in which the heat generating part 622 is routed (arrow AR12) are separated without overlapping each other.

[0069] 7(B), the second region HB2 may be divided into a left region HB23 and a right region HB24, and the entire heat generating portion 621 may be disposed in region HB23, and the entire heat generating portion 622 may be disposed in region HB24. In the example of FIG. 7(B), the circumferential range in which the heat generating portion 621 is routed (arrow AR13) and the circumferential range in which the heat generating portion 622 is routed (arrow AR14) are separated without overlapping each other.

[0070] 6, in the present embodiment, the radial range in which the heat generating portion 621 (first heat generating portion) is routed and the radial range in which the heat generating portion 622 (second heat generating portion) is routed overlap with each other in top view. Also, the circumferential range in which the heat generating portion 621 (first heat generating portion) is routed and the circumferential range in which the heat generating portion 622 (second heat generating portion) is routed overlap with each other. In other words, the heat generating portion 621 and the heat generating portion 622 are routed in paths that intertwine with each other in both the radial and circumferential directions.

[0071] The reason for adopting such a configuration will be explained. When examining the wiring path of the heat generating part of the heater unit 300, it is necessary to take into consideration various surrounding structures so as not to generate so-called hot spots or cool spots. For example, when the shape of the coolant flow path 250 in the base plate 200 is partially changed, or when the position or size of the gas hole (not shown) formed in the dielectric substrate 100 is changed, it becomes necessary to partially change the wiring path of the heat generating part accordingly.

[0072] In this case, if the range in which the heat generating part 621 is routed and the range in which the heat generating part 622 is routed are separated from each other as in the examples of FIG. 7, when the route of the heat generating part is "partially" changed, only the route of one of the heat generating parts 621 and 622 is changed. As a result, the difference between the length of the heat generating part 621 and the length of the heat generating part 622 becomes large, and the difference in the amount of heat generated also becomes large, so there is a concern that this may adversely affect the in-plane temperature distribution of the substrate W during processing. In order to prevent this, the entire route of the heat generating parts 621 and 622 must be redesigned from scratch. However, it is not efficient to redesign the entire heat generating parts 621 and 622 from scratch every time the structure of the base plate 200 or the like is partially changed.

[0073] In contrast, in this embodiment, as described above, the heat generating portion 621 and the heat generating portion 622 are routed in a mutually intertwining manner in both the radial direction and the circumferential direction. Therefore, when the route of the heat generating portion is partially changed, both the heat generating portion 621 and the heat generating portion 622 are simultaneously changed in a similar manner. Since the difference between the length of the heat generating portion 621 and the length of the heat generating portion 622 hardly changes, the above problem is unlikely to occur. When the structure of the base plate 200 or the like is partially changed, the heat generation amount in each portion can be kept roughly uniform without losing its balance, even if the route of the heat generating portion 621 and the heat generating portion 622 is "partially" changed accordingly.

[0074] In the above, a configuration has been described in which a heater for heating the dielectric substrate 100 is provided outside the dielectric substrate 100 in a state where it is unitized as the heater unit 300. However, the above-described configuration can also be applied to a configuration in which a heater is provided inside the dielectric substrate 100.

[0075] 6 may be embedded in the dielectric substrate 100, like the attraction electrode 130. Even in this embodiment, the same effects as those of the present embodiment can be achieved.

[0076] The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Any design modifications made by a person skilled in the art to these specific examples are also included within the scope of the present disclosure as long as they have the features of the present disclosure. The elements of each of the above-mentioned specific examples and their arrangements, conditions, shapes, etc. are not limited to those exemplified and can be changed as appropriate. The combination of each of the elements of each of the above-mentioned specific examples can be changed as appropriate as long as no technical contradiction occurs. [Explanation of symbols]

[0077] 10: Electrostatic chuck 100: Dielectric substrate 110: Face 300: Heater unit 610: First heater 611: Heat generating part 620: Second heater 621, 622: Heat generating part HB1: 1st area HB2:Second area LH: Lift pin hole

Claims

1. a dielectric substrate having a mounting surface on which an object to be attached is placed; a heater for heating the dielectric substrate, the dielectric substrate has a first region and a second region adjacent to each other when viewed in a direction perpendicular to the mounting surface, The heater is A first heater disposed at a position corresponding to the first region; a second heater disposed at a position corresponding to the second region; Each of the first heater and the second heater includes a heat generating portion that is a conductor that is wire-wound, a line width of the heat generating portion of the second heater is narrower than a line width of the heat generating portion of the first heater, The electrostatic chuck according to claim 1, wherein the second heater includes a plurality of the heat generating portions connected in parallel to each other.

2. When viewed from a direction perpendicular to the placement surface, the first region is a circular region including a center of the dielectric substrate, 2. The electrostatic chuck according to claim 1, wherein the second region is a region that completely surrounds the first region from the outside.

3. The dielectric substrate has a through hole for inserting a lift pin therethrough, The electrostatic chuck according to claim 2 , wherein the second region is a region including a portion where the through hole is formed.

4. 2. The electrostatic chuck according to claim 1, wherein the first heater is provided with only one heat generating portion.

5. The second heater includes, as the heat generating portion, a first heat generating portion and a second heat generating portion connected in parallel to each other, When viewed from a direction perpendicular to the placement surface, A radial range in which the first heat generating portion is routed and a radial range in which the second heat generating portion is routed overlap each other, 2. The electrostatic chuck according to claim 1, wherein a circumferential range in which the first heat generating portion is routed and a circumferential range in which the second heat generating portion is routed overlap with each other.

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