Electrostatic chuck

Abstract

To provide an electrostatic chuck capable of preventing short circuits between a bypass section and a power supply terminal.SOLUTION: An electrostatic chuck 10 comprises a dielectric substrate 100 and a heater unit 300 for heating the dielectric substrate 100. The heater unit 300 comprises a heating section 351 which is a conductor wound in a linear configuration and generates heat when supplied with power from an external source, a bypass layer 370 positioned at a height different from the heating section 351, and a power supply terminal 390 bonded to the bypass layer 370. In the top view, the heating section 351 is routed along a path that does not pass through a region D1, which overlaps the power supply terminal 390.SELECTED DRAWING: Figure 8

Description

[Technical Field]

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

[0002] For example, semiconductor manufacturing equipment such as etching equipment is provided with an electrostatic chuck 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, attracting and holding the substrate placed on the dielectric substrate.

[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 temperature adjustment with high precision, electrostatic chucks equipped with heaters have been developed in recent years and are already in practical use. Patent Document 1 listed below describes an electrostatic chuck configured such that a heater is disposed between a dielectric substrate and a base plate. [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 present inventors have been studying the possibility of unitizing a heater used in an electrostatic chuck. When unitizing a heater, it is preferable to provide a bypass section in addition to a heat generating section, which is a conductor drawn in a linear shape. The bypass section is a section to which a power supply terminal that receives power from an external source is connected. By providing the bypass section, it becomes possible to increase the degree of freedom in arranging the power supply terminal on the heater.

[0006] When the bypass section and the power supply terminal are joined by, for example, resistance spot welding, heat is applied to the power supply terminal and its surrounding area. If the heat-generating section is routed along a path that passes through the area directly above the power supply terminal, the insulating layer between the heat-generating section and the bypass section may be damaged by the heat, causing a short circuit between them. As a result, current may flow along an unexpected path, which may prevent the temperature of the dielectric substrate from being properly regulated.

[0007] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an electrostatic chuck that can prevent a short circuit between a bypass portion and a power supply terminal. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides an electrostatic chuck including a dielectric substrate having a mounting surface on which an object to be attracted is mounted, and a heater for heating the dielectric substrate. The heater is a linear conductor and includes a heat generating portion that generates heat upon receiving power from an external source, a bypass portion provided at a different height from the heat generating portion, and a power supply terminal connected to the bypass portion. When viewed from a direction perpendicular to the mounting surface, the heat generating portion is routed along a path that does not pass through an area that overlaps with the power supply terminal.

[0009] In the electrostatic chuck having the above configuration, the heat generating portion of the heater is routed along a path that does not pass through the area that overlaps with the power supply terminal in a top view, i.e., the area to which heat is applied when the power supply terminal is joined, thereby preventing a short circuit caused by heat during joining between the bypass portion and the power supply terminal. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an electrostatic chuck that can prevent a short circuit between the bypass portion and the power supply terminal. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view schematically illustrating a configuration of an electrostatic chuck according to an embodiment of the present invention. [Figure 2] FIG. 2 is an exploded view schematically illustrating the configuration of the heater unit. [Figure 3] 10A and 10B are diagrams illustrating an example of the arrangement of sub-heater layers in a heater unit. [Figure 4] FIG. 1 is a diagram showing the configuration of one sub-heater layer. [Figure 5] 10A and 10B are diagrams illustrating an example of the arrangement of main heater layers in a heater unit. [Figure 6] FIG. 1 is a diagram showing the configuration of one main heater layer. [Figure 7] FIG. 10 is a diagram for explaining the role of a bypass layer, etc. [Figure 8] 10A and 10B are diagrams for explaining the positional relationship between the range in which the heat generating portion is routed and the power supply terminal; [Figure 9] 10A and 10B are diagrams for explaining examples of routing of a heat generating portion. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components in the drawings will be denoted by the same reference numerals as much as possible, and duplicated descriptions will be omitted.

[0013] 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 also be used in apparatuses other than semiconductor manufacturing apparatuses.

[0014] 1 is a schematic cross-sectional view showing the configuration of an electrostatic chuck 10 in a state where it attracts and holds a substrate W. The electrostatic chuck 10 includes a dielectric substrate 100, a base plate 200, and a heater 300.

[0015] 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 also 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.

[0016] 1 of the dielectric substrate 100 is a "mounting surface" on which the substrate W is placed. Also, a lower surface 120 of the dielectric substrate 100 in FIG. 1 is a "bonding surface" that is bonded to the heater 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 also be referred to as a "top view."

[0017] An attraction electrode 130 is embedded inside the dielectric substrate 100. The attraction electrode 130 is a thin, flat layer made of a metal material such as tungsten, and is disposed parallel to the surface 110. The attraction electrode 130 may be made of a material other than tungsten, such as molybdenum, platinum, or palladium. When a voltage is applied to the attraction 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 attracting and holding the substrate W. The power supply path may be configured in any of various well-known ways. The attraction electrode 130 may be provided as a single so-called "monopolar" electrode as in this embodiment, or as two so-called "bipolar" electrodes.

[0018] As shown in Fig. 1, a space SP is formed between the dielectric substrate 100 and the substrate W. When a process such as etching is performed in the semiconductor manufacturing equipment, helium gas for temperature adjustment is supplied to the space SP from the outside 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, thereby maintaining the temperature of the substrate W at an appropriate temperature. Note that the temperature adjustment gas supplied to the space SP may be a gas other than helium.

[0019] A seal ring 111 and dots 112 are provided on a surface 110 that is a mounting surface, and the space SP is formed around these.

[0020] The seal ring 111 is a wall that divides the space SP at the outermost position. The upper end of the seal ring 111 forms part of the surface 110 and abuts against the substrate W. Note that multiple 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.

[0021] 1, the portion marked with the reference numeral "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 portion of the surface 110 to the position of the bottom surface 116.

[0022] The dots 112 are circular protrusions that protrude 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 comes into contact with the substrate W. By providing a plurality of such dots 112, bending of the substrate W is suppressed.

[0023] The base plate 200 is a substantially disk-shaped member that supports the dielectric substrate 100 and the heater 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 300 via a bonding layer 420.

[0024] A coolant flow path 250 for flowing a coolant is formed inside the base plate 200. When a process such as etching is performed in the semiconductor manufacturing equipment, 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. The coolant is supplied to and discharged from the coolant flow path 250 through an opening (not shown) formed in a surface 220 of the base plate 200 opposite to the surface 210.

[0025] 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 an insulating film, the dielectric strength of the base plate 200 can be increased.

[0026] The heater 300 generates heat when power is supplied from an external source, and heats the dielectric substrate 100. As will be described later, the heater 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 adjusted individually. By adjusting the amount of heat generated by each part individually, the in-plane temperature distribution of the substrate W during processing can be made closer to uniform.

[0027] The heater 300 is sandwiched between the dielectric substrate 100 and the base plate 200 and is bonded to each of them. The heater 300 and the dielectric substrate 100 are bonded via a bonding layer 410, and the heater 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, curing a silicone adhesive. A plurality of particulate fillers are disposed inside each of the layers to increase thermal conductivity. For example, particles containing alumina as a main component can be used as the filler.

[0028] The specific configuration of the heater 300 will be described. FIG. 2 shows a schematic exploded view of the configuration of the heater 300. As shown in the figure, the heater 300 has a support plate 310 (310A), an insulating layer 320, a sub-heater layer 330, an insulating layer 340, a main heater layer 350, an insulating layer 360, a bypass layer 370, an insulating layer 380, a support plate 310 (310B), and a power supply terminal 390. In this embodiment, the sub-heater layer 330, the main heater layer 350, and the bypass layer 370 are arranged in this order from top to bottom in FIG. 2, but the arrangement order of these layers may be different from that of this embodiment.

[0029] The support plate 310 is a substantially disk-shaped member and is provided at each of the upper and lower ends of the heater 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 that is bonded to the dielectric substrate 100 via a bonding layer 410, and the support plate 310B is a portion that is bonded to the base plate 200 via a bonding layer 420.

[0030] The pair of support plates 310A, 310B are members for reinforcing the entire heater 300 by sandwiching the entire sub-heater layer 330, main heater layer 350, bypass layer 370, etc. between them. In this embodiment, both support plates 310A, 310B are made of metal, but they may also be made of other materials (e.g., insulating materials). Note that each of the members constituting the heater 300, such as the support plate 310, has a plurality of through holes formed therein for the purpose of passing lift pins through, etc., but these are not shown in FIG. 2.

[0031] The insulating layer 320 is provided between the support plate 310A and the sub-heater layer 330 to electrically insulate them from each other. The insulating layer 320 also serves to physically bond them to each other. In this embodiment, the insulating layer 320 is a polyimide film, but it may contain components other than polyimide or may be made of a material other than polyimide. If the support plate 310A is made of an insulating material, the insulating layer 320 can be eliminated.

[0032] The sub-heater layer 330 generates heat when power is supplied from an external source. In Figure 2, the sub-heater layer 330 is depicted as a single disk, but in reality, the sub-heater layer 330 is divided into multiple regions, and each region can be individually heated. The specific configuration of the sub-heater layer 330 will be described later.

[0033] The insulating layer 340 is provided between the sub-heater layer 330 and the main heater layer 350 to electrically insulate them from each other. The insulating layer 340 also serves to physically bond them to each other. In this embodiment, the insulating layer 340 is a polyimide film, but it may contain components other than polyimide or may be made of a material other than polyimide.

[0034] The main heater layer 350, like the sub-heater layer 330 described above, generates heat when power is supplied from an external source. In Figure 2, the main heater layer 350 is depicted as a single disk, but in reality, the main heater layer 350 is divided into multiple regions, and each region can be individually heated. The specific configuration of the main heater layer 350 will be described later.

[0035] The main heater layer 350 generates a larger amount of heat per unit area than the sub-heater layer 330 described above. The main heater layer 350 is intended to raise the temperature of the entire dielectric substrate 100 in a short period of 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 more uniform. In this way, in this embodiment, two heater layers are provided separately, each with its own role.

[0036] The insulating layer 360 is provided between the main heater layer 350 and the bypass layer 370 to electrically insulate them from each other. The insulating layer 360 also serves to physically bond them to each other. In this embodiment, the insulating layer 360 is a polyimide film, but it may contain a component other than polyimide, or may be made of a material other than polyimide.

[0037] The bypass layer 370 is a layer for electrically connecting a power supply terminal 390 (described later) to the sub-heater layer 330 and the main heater layer 350. In FIG. 2, the bypass layer 370 is schematically depicted as a single disk, but in reality, the bypass layer 370 is divided into multiple pieces. By providing the bypass layer 370 in the middle of the electric path connected to the sub-heater layer 330, etc., it becomes possible to adjust the position of the power supply terminal 390, etc. A portion of each of the divided bypass layers 370 is electrically connected to the sub-heater layer 330 or the main heater layer 350.

[0038] As is clear from Fig. 2, the bypass layer 370 is provided at a different height position from the sub-heater layer 330 and the main heater layer 350. The "height position" here refers to a position along a direction perpendicular to the surface 110, which is the mounting surface (the up-down direction in Fig. 2). The bypass layer 370 corresponds to the "bypass section" in this embodiment.

[0039] The insulating layer 380 is provided between the bypass layer 370 and the support plate 310B to electrically insulate them from each other. The insulating layer 380 also serves to physically bond them to each other. In this embodiment, the insulating layer 380 is a polyimide film, but it may contain components other than polyimide or may be made of a material other than polyimide. If the support plate 310B is made of an insulating material, the insulating layer 380 may be eliminated.

[0040] 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.

[0041] The power supply terminal 390 is a part that receives, from the outside, the power required to generate heat in the sub-heater layer 330 and the like. In this embodiment, the power supply terminal 390 is formed as a long, thin, rod-shaped plug, one end of which is joined to the bypass layer 370. A plurality of power supply terminals 390 are provided, corresponding 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 terminals 390, and the power supply terminals 390 are inserted through the through holes.

[0042] The structure of the sub-heater layer 330 will now be described. As mentioned above, the sub-heater layer 330 is divided into multiple regions, and each region can generate heat independently. Figure 3 shows an example of how the sub-heater layer 330 is divided from a top view. In this example, the sub-heater layer 330 is divided into a total of 24 regions HA.

[0043] The sub-heater layer 330 is configured as linear heat generating portions 331, which are individually routed in each region HA. That is, in this embodiment, a total of 24 heat generating portions 331 are provided.

[0044] 4 shows an example of a heat generating portion 331 routed in one area HA. ​​In each area HA, one linear heat generating portion 331 is routed along a path that passes uniformly through almost the entire area. The heat generating portion 331 is a portion that generates heat when power is supplied from an external source.

[0045] Circular pad portions 332, 333 are formed on both ends of the heat generating portion 331. The heat generating portion 331 and the pad portions 332, 333 are formed, for example, by etching a thin metal foil, and the entire portion functions as one sub-heater layer 330. In other words, one sub-heater layer 330 is provided for each of the 24 regions HA.

[0046] 4 is a schematic view of the heat generating portion 331 and differs from the actual shape. The same applies to the positions of the pad portions 332 and 333.

[0047] The structure of the main heater layer 350 will now be described. Like the sub-heater layer 330, the main heater layer 350 is also divided into multiple regions, and each region can generate heat independently. Figure 5 shows an example of how the main heater layer 350 is divided from a top view. In this example, the main heater layer 350 is divided into a total of three regions HB.

[0048] The main heater layer 350 is configured as linear heat generating portions 351, which are individually routed in each region HB. That is, in this embodiment, a total of three heat generating portions 351 are provided.

[0049] 6 shows an example of heat generating parts 351 routed in one area HB. In each area HB, one linear heat generating part 351 is routed along a path that passes uniformly through almost the entire area. The heat generating part 351 is a part that generates heat when power is supplied from an external source. The number of heat generating parts 351 (3 in total) is fewer than the number of heat generating parts 331 (24 in total).

[0050] Circular pad portions 352, 353 are formed on both ends of the heat generating portion 351. The heat generating portion 351 and the pad portions 352, 353 are formed, for example, by etching a thin metal foil, and the entire portion functions as one main heater layer 350. In other words, one main heater layer 350 is provided for each of the three regions HB.

[0051] 6 is a schematic view of the heat generating portion 351 and differs from the actual shape. The same applies to the positions of the pad portions 352 and 353.

[0052] 7 is a schematic perspective view showing two regions HA, two sub-heater layers 330 arranged therein, and a bypass layer 370 connected to the sub-heater layers 330. One of the two regions HA shown in FIG. 7 will also be referred to as "region HA1" below. The other region HA will also be referred to as "region HA2" below. Note that the shapes of the heat generating portion 331 and other components shown in FIG. 7 are schematic and differ from the actual shapes.

[0053] As described above, the bypass layer 370 is divided into multiple pieces. In FIG. 7, only three of the multiple divided bypass layers 370 are shown. Of the three divided bypass layers 370, the one marked with the reference symbol "370A" in FIG. 7 is arranged in a position overlapping only one region HA in top view. In other words, each of the bypass layers 370 is individually arranged in a position directly below each region HA. The portion of the bypass layer 370 arranged in this manner will also be referred to as the "bypass layer 370A" hereinafter.

[0054] 7 is disposed at a position overlapping both the region HA1 and the region HA2 in top view. The portion of the bypass layer 370 disposed in this manner is hereinafter also referred to as the "bypass layer 370B."

[0055] In the sub-heater layer 330 arranged in the region HA1, the pad portion 332 at one end of the heat generating portion 331 is electrically connected to the bypass layer 370A located immediately below it, and the pad portion 333 at the other end of the heat generating portion 331 is electrically connected to the bypass layer 370B.

[0056] The same applies to the sub-heater layer 330 arranged in region HA2, where a pad portion 332 at one end of the heat generating portion 331 is electrically connected to the bypass layer 370A located immediately below it, and a pad portion 333 at the other end of the heat generating portion 331 is electrically connected to the bypass layer 370B.

[0057] The electrical connection of each of the above-described parts is realized, for example, by welding the upper and lower layers together. To make the configuration easier to understand, in Fig. 7, each welded part is schematically depicted as a linear rod-shaped member (the part indicated by the reference numeral 301). In the parts overlapping with each welded part in top view, openings are formed in each of the layers (insulating layer 340, main heater layer 350, and insulating layer 360) between the sub-heater layer 330 and the bypass layer 370, and the sub-heater layer 330 and the bypass layer 370 are directly connected through these openings.

[0058] The sub-heater layer 330 and the bypass layer 370 may be electrically connected by welding as in this embodiment, but may also be electrically connected by other methods. For example, they may be electrically connected via a conductive member extending vertically. In either configuration, the sub-heater layer 330 and the bypass layer 370 are connected via an electrical path indicated by reference numeral 301 in FIG. 7 . This electrical path will hereinafter also be referred to as the "connection portion 301."

[0059] One end of a power supply terminal 390 is joined to each bypass layer 370A from below in FIG. 7. A voltage is individually applied to each of these power supply terminals 390 from an external DC power supply. Similarly, one end of a power supply terminal 390 is joined to the bypass layer 370B from below in FIG. 7. This power supply terminal 390 is grounded.

[0060] As described above, one pad portion 332 of each of the sub-heater layers 330 provided for each region HA is connected to an individual DC power supply via the bypass layer 370A, and the other pad portion 333 is grounded via the common bypass layer 370B. The other sub-heater layers 330 not shown in Fig. 7 are also connected to DC power supplies or the like in a similar configuration. With this configuration, it is possible to individually supply power to each of the multiple sub-heater layers 330 provided and adjust the amount of heat generated at each portion.

[0061] It is also possible to supply power to the sub-heater layer 330 directly from the power supply terminal 390 without passing through the bypass layer 370. However, by using a configuration in which power is supplied via the bypass layer 370 as in this embodiment, it is possible to increase the degree of freedom in arranging the power supply terminals 390 and to consolidate the power supply terminals 390 that are grounded into one.

[0062] The supply of power to each main heater layer 350 is also achieved by the same configuration as above. The specific configuration is the same as that shown in Fig. 7, so its description and illustration will be omitted.

[0063] FIG. 8 shows a schematic side view of the configuration of the sub-heater layer 330, main heater layer 350, bypass layer 370, and power supply terminal 390 provided in the heater 300.

[0064] The heat generating portion 351 provided in the main heater layer 350 corresponds to the "first heat generating portion" in this embodiment. The heat generating portion 331 provided in the sub-heater layer 330 is a heat generating portion provided at a different height position from the heat generating portion 351, and corresponds to the "second heat generating portion" in this embodiment.

[0065] The bypass layer 370 arranged on the left side in Fig. 8 is electrically connected to the heat generating portion 351 (first heat generating portion) via a connection portion 302. This bypass layer 370 will also be referred to as a "first bypass portion 371" below. The connection portion 302 is similar to the connection portion 301 shown in Fig. 7, and is a portion that connects the heat generating portion 351 (first heat generating portion) and the first bypass portion 371 by, for example, welding.

[0066] 8 is electrically connected to the heat generating portion 331 (second heat generating portion) via the connection portion 301. This bypass layer 370 is also referred to as the "second bypass portion 372" below.

[0067] The power supply terminal 390 located on the left side in FIG. 8 is joined to the first bypass section 371. This power supply terminal 390 will also be referred to as the "first power supply terminal 391" below. The power supply terminal 390 located on the right side in FIG. 8 is joined to the second bypass section 372. This power supply terminal 390 will also be referred to as the "second power supply terminal 392" below.

[0068] A circular flange FL is formed at the upper end of each power supply terminal 390 when viewed from above. The power supply terminal 390 is joined to the bypass layer 370 by resistance spot welding, with the flange FL abutting against the bypass layer 370 from below. The resistance spot welding is performed by arranging a pair of electrodes in parallel on the left and right, and pressing these electrodes against the flange FL from below in FIG. 8. In FIG. 8, the welded locations are marked with the symbol "WD."

[0069] 8, the region marked with the symbol "D1" is a region that overlaps with the first power supply terminal 391 in top view, specifically, a circular region that overlaps with the flange FL of the first power supply terminal 391 in top view. This region will also be referred to as "region D1" below. The region marked with the symbol "D2" in the same figure is a region that overlaps with the second power supply terminal 392 in top view, specifically, a circular region that overlaps with the flange FL of the second power supply terminal 392 in top view. This region will also be referred to as "region D2" below. The region marked with the symbol "D3" in the same figure is a circular region that encompasses the entire connecting portion 302 in top view. This region will also be referred to as "region D3" below.

[0070] The resistance spot welding is performed from the bottom side of FIG. 8 after the entire heater 300 (including the sub-heater layer 330, main heater layer 350, and bypass layer 370) is laminated. If the heat-generating portion 351 were routed along a path passing through region D1, the insulating layer 360 (not shown in FIG. 8; see FIG. 2) between the heat-generating portion 351 and the first bypass portion 371 could be damaged by the heat of welding, resulting in a short circuit between the heat-generating portion 351 and the first bypass portion 371. As a result, current could flow along an unexpected path, potentially preventing proper temperature control of the dielectric substrate 100. This problem could also occur if the heat-generating portion 351 were routed along a path passing through region D2.

[0071] Therefore, in the heater 300 according to this embodiment, the heat generating portion 351 (first heat generating portion) is routed along a path that does not pass through either region D1 or region D2. In this configuration, even if a part of the insulating layer 360 is damaged by heat during welding, it is possible to prevent a situation in which a short circuit occurs between the heat generating portion 351 and the first bypass portion 371 or between the heat generating portion 351 and the second bypass portion 372 through the damaged part.

[0072] 9 illustrates the configuration of heat generating portion 351 routed near region D1 in a top view. As shown in the figure, heat generating portion 351 is routed along a path that protrudes in an arc shape so as to surround region D1 from the outside without intersecting with region D1 in a top view. In this way, the portion of heat generating portion 351 that is routed along the path that protrudes in an arc shape will be referred to as "protrusion 351A" below.

[0073] In this embodiment, the line widths of each portion of the heat generating portion 351 are adjusted so that the line width W2 of the protruding portion 351A of the heat generating portion 351 is smaller than the line width W1 of the portion of the heat generating portion 351 that is connected to the protruding portion 351A. That is, in this embodiment, the line width of the heat generating portion 351 is locally smaller at the protruding portion 351A.

[0074] In this configuration, the electrical resistance of the protrusion 351A increases locally, thereby increasing the amount of Joule heat generated in that area. Therefore, even if the arrangement density of the heat-generating portions 351 near the protrusion 351A is locally sparse, it is possible to suppress a decrease in the amount of heat generated in that area. As a result, it is possible to suppress variations in the in-plane temperature distribution of the substrate W during processing.

[0075] Near area D2, heat generating portion 351 is routed along the same path as in Fig. 9. Note that the configuration of heat generating portion 351 shown in Fig. 9 is merely an example. The configuration of heat generating portion 351 routed around area D1 and area D2 may be different from that shown in Fig. 9.

[0076] Returning to FIG. 8 , the explanation will be continued. As described above, the heat generating portion 351 (first heat generating portion) of this embodiment is routed along a path that does not pass through either region D1 or region D2 that overlaps with the power supply terminal 390 in a top view. Furthermore, in this embodiment, the heat generating portion 331 (second heat generating portion) is also routed along a path that does not pass through either region D1 or region D2. This prevents a situation in which a short circuit occurs between the heat generating portion 331 and the heat generating portion 351, or between the heat generating portion 331 and the bypass layer 370, via the damaged portion, even if a part of the insulating layer 340 or the like is damaged by heat during welding. The configuration of the heat generating portion 331 routed around region D1 or region D2 is the same as the configuration of the heat generating portion 351 shown in FIG. 9.

[0077] In FIG. 8, the portions of the heat generating portion 331 and the heat generating portion 351 that are routed so as not to pass through the area D1 and the like are indicated by dotted lines.

[0078] When focusing on the first power supply terminal 391 shown in FIG. 8, the first bypass section 371 to which the first power supply terminal 391 is connected and the heat generating section 351 that is routed along a path that does not pass through the area D1 directly above the first power supply terminal 391 are electrically connected via the connection section 302.

[0079] Similarly, when focusing on the second power supply terminal 392 shown in Figure 8, the second bypass section 372 to which the second power supply terminal 392 is connected and the heat generating section 331 which is routed along a path that does not pass through the area D2 directly above the second power supply terminal 392 are electrically connected via the connection section 301.

[0080] Furthermore, when focusing on the second power supply terminal 392 shown in FIG. 8, the heat generating portion 351 (first heat generating portion) that is not electrically connected to the second power supply terminal 392 is routed along a path that does not pass through the area D2 directly above the second power supply terminal 392.

[0081] Similarly, when focusing on the first power supply terminal 391 shown in Figure 8, the heat generating portion 331 (second heat generating portion) that is not electrically connected to the first power supply terminal 391 is routed along a path that does not pass through the area D1 directly above the first power supply terminal 391.

[0082] Incidentally, insulating layer 340 is located in a position that is relatively difficult for heat during welding to reach, compared to insulating layer 360. Therefore, if there is a sufficiently low possibility that heat during welding will damage insulating layer 360 at the back, heat generating portion 331 may be routed along a path that passes through region D1 and region D2. In other words, heat generating portion 351 (first heat generating portion) may be routed along a path that does not pass through region D1 or region D2, while heat generating portion 331 (second heat generating portion) may be routed along a path that passes through region D1 and region D2.

[0083] 8 is a portion that electrically connects the first bypass portion 371 and the heat generating portion 351 (first heat generating portion). Also, region D3 shown in the figure is a circular region that encompasses the entire connecting portion 302 in top view. In other words, region D3 encompasses the entire region that overlaps with connecting portion 302 in top view. Region D3 may completely coincide with the region that overlaps with connecting portion 302 in top view.

[0084] In this embodiment, the heat generating portion 331 (second heat generating portion) is routed along a path that does not pass through the above-mentioned region D3. With this configuration, it is possible to prevent a short circuit between the heat generating portion 331 and the heat generating portion 351 during welding to form the connection portion 302.

[0085] The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Design modifications to these specific examples made by a person skilled in the art as appropriate are also included within the scope of the present disclosure as long as they comprise the features of the present disclosure. The elements of the above-described specific examples, as well as their arrangement, conditions, shape, etc., are not limited to those exemplified and can be modified as appropriate. The elements of the above-described specific examples can be combined in various ways as appropriate, as long as no technical contradictions arise. [Explanation of symbols]

[0086] 10: Electrostatic chuck 100: Dielectric substrate 110: Face 300: Heater 331, 351: Heat generating part 370: Bypass layer 371: First bypass section 372: Second bypass section 390: Power supply terminal 391: First power supply terminal 392: Second power supply terminal D1,D2,D3:Area W: Substrate

Claims

1. a dielectric substrate having a mounting surface on which an object to be attracted is placed; a heater for heating the dielectric substrate, The heater is a heat generating portion that is a linear conductor and generates heat when supplied with power from an external source; a bypass portion provided at a different height from the heat generating portion; a power supply terminal joined to the bypass portion, When viewed from a direction perpendicular to the placement surface, The electrostatic chuck is characterized in that the heat generating portion is routed along a path that does not pass through an area overlapping with the power supply terminal.

2. 2. The electrostatic chuck according to claim 1, wherein the heat generating portion and the bypass portion are electrically connected to each other.

3. The heat generating portion is A first heat generating portion; a second heat generating portion provided at a different height position from the first heat generating portion, The bypass section a first bypass portion electrically connected to the first heat generating portion; a second bypass portion electrically connected to the second heat generating portion, The power supply terminal is a first power supply terminal joined to the first bypass portion; a second power supply terminal joined to the second bypass portion, When viewed from a direction perpendicular to the placement surface, 2. The electrostatic chuck according to claim 1, wherein the first heat generating portion is routed along a path that does not pass through a region overlapping with the second power supply terminal.

4. When viewed from a direction perpendicular to the placement surface, 4. The electrostatic chuck according to claim 3, wherein the second heat generating portion is routed along a path that does not pass through a region overlapping with the first power supply terminal.

5. The heater is a connection portion that electrically connects the first bypass portion and the first heat generating portion, When viewed from a direction perpendicular to the placement surface, 4. The electrostatic chuck according to claim 3, wherein the second heat generating portion is routed along a path that does not pass through an area overlapping with the connecting portion.

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