Electrostatic chuck

Abstract

To provide an electrostatic chuck capable of suppressing the thickness of a dielectric substrate while precisely adjusting the in-plane temperature distribution of the substrate by a heater.SOLUTION: The electrostatic chuck 10 includes a dielectric substrate 100 and a heater for heating the dielectric substrate 100. The heater includes an internal heater 300 provided inside the dielectric substrate 100 and an external heater unit 400 provided outside the dielectric substrate 100.SELECTED DRAWING: Figure 1

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] During substrate processing, it is necessary to make the temperature distribution within the surface of the substrate as uniform as possible. In order to enable the temperature distribution within the surface of the substrate to be adjusted with high precision, electrostatic chucks equipped with heaters for heating dielectric substrates have been developed in recent years and have already been put into practical use. For example, Patent Document 1 listed below describes an electrostatic chuck equipped with both a low-output sub-heater and a high-output main heater. With this configuration, it is possible to increase the temperature of the substrate in a short time using the main heater and to make the temperature distribution within the surface of the substrate uniform using the sub-heater. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-55292 Summary of the Invention [Problem to be solved by the invention]

[0005] In the electrostatic chuck described in Patent Document 1, the main heater and the sub-heater are entirely unitized and provided outside the dielectric substrate. By providing the entire heater outside the dielectric substrate rather than inside it, the dielectric substrate can be made thinner. However, compared to a configuration in which the entire heater is provided inside the dielectric substrate, it may be more difficult to precisely adjust the temperature distribution within the surface of the substrate.

[0006] The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an electrostatic chuck that can precisely adjust the in-plane temperature distribution of a substrate using a heater while suppressing the thickness of a dielectric substrate. [Means for solving the problem]

[0007] In order to solve the above problems, the 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 heater includes a first heater provided inside the dielectric substrate and a second heater provided outside the dielectric substrate.

[0008] In an electrostatic chuck having such a configuration, the first heater is provided inside the dielectric substrate, so that the temperature distribution within the surface of the substrate can be adjusted more precisely. Also, instead of providing the entire heater inside the dielectric substrate, the second heater is provided outside the dielectric substrate, so that the dielectric substrate does not become too thick due to the inclusion of the heater. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide an electrostatic chuck that can precisely adjust the in-plane temperature distribution of the substrate using a heater, while also being able to reduce the thickness of the dielectric substrate. [Brief explanation of the drawings]

[0010] [Figure 1]1 is a cross-sectional view schematically showing the configuration of an electrostatic chuck according to a first embodiment. [Figure 2] FIG. 10 is a diagram showing an example of how to divide the built-in heaters. [Figure 3] FIG. 10 is a diagram showing an example of a first heat generating portion routed in one region. [Figure 4] FIG. 4 is a diagram for explaining the role of a first bypass section, etc. [Figure 5] FIG. 2 is an exploded view showing a schematic configuration of an external heater unit. [Figure 6] 10A and 10B are diagrams illustrating an example of how heat generating layers in an external heater unit are divided. [Figure 7] FIG. 10 is a diagram showing an example of a second heat generating portion routed in one region. [Figure 8] FIG. 10 is a diagram for explaining the role of a second bypass section, etc. [Figure 9] FIG. 10 is a cross-sectional view schematically showing the configuration of an electrostatic chuck according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] 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.

[0012] A first embodiment will be described. An 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 object to be attracted, that is, the substrate W, is, for example, a silicon wafer. The electrostatic chuck 10 may also be used in apparatuses other than semiconductor manufacturing apparatuses.

[0013] 1 is a schematic cross-sectional view showing the configuration of an electrostatic chuck 10 that attracts and holds a substrate W. The electrostatic chuck 10 includes a dielectric substrate 100, a base plate 200, a built-in heater 300, and an external heater unit 400.

[0014] 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.

[0015] 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 "bonding surface" that is bonded to the external heater unit 400 via a bonding layer 510. 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."

[0016] An attraction electrode (not shown) is embedded inside the dielectric substrate 100. The attraction electrode is a thin, flat layer made of a metal material such as tungsten, and is disposed parallel to the surface 110. In addition to tungsten, the attraction electrode may be made of molybdenum, platinum, palladium, or the like. When a voltage is applied to the attraction electrode from the outside, an electrostatic force is generated between the surface 110 and the substrate W, thereby attracting and holding the substrate W.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] The base plate 200 is a substantially disk-shaped member that supports the dielectric substrate 100 and the external heater unit 400. 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 external heater unit 400 via a bonding layer 520.

[0023] 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.

[0024] 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.

[0025] The built-in heater 300 generates heat upon receiving an external power supply and heats the dielectric substrate 100. The built-in heater 300 is provided inside the dielectric substrate 100. The built-in heater 300 has a first heat generating portion 331, a first bypass portion 350, and a first power supply terminal 390.

[0026] The first heat generating portion 331 is a linear conductor that generates heat when power is supplied from an external source. The first heat generating portion 331 is routed along a plane parallel to the surface 110 at a height position closer to the surface 120 than an attraction electrode (not shown) (lower in FIG. 1).

[0027] The built-in heater 300 is divided into multiple regions that do not overlap each other when viewed from above, and each region has one first heat generating portion 331. In other words, the built-in heater 300 includes multiple first heat generating portions 331 corresponding to the number of the above regions. By individually adjusting the heat generation amount of each first heat generating portion 331, it is possible to make the in-plane temperature distribution of the substrate W during processing more uniform.

[0028] 2 shows a top view of an example of how the built-in heater 300 is divided into regions. In this example, the built-in heater 300 is divided into a total of 24 regions HA. The linear first heat generating portion 331 is routed individually in each region HA. In other words, in this embodiment, a total of 24 first heat generating portions 331 are provided.

[0029] 3 shows an example of the first heat generating part 331 routed in one area HA. ​​In each area HA, one linear first heat generating part 331 is routed along a path that passes uniformly through almost the entire area.

[0030] Circular pad portions 332, 333 are formed on both ends of the first heat generating portion 331. The first heat generating portion 331 and the pad portions 332, 333 are formed by screen printing a metal material such as tungsten. Note that the shape of the first heat generating portion 331 shown in Fig. 3 is a schematic and differs from the actual shape. The same applies to the positions of the pad portions 332, 333.

[0031] Power is supplied to the first heating portion 331 via a first power supply terminal 390 and a first bypass portion 350. As shown in FIG. 1, the first power supply terminal 390 is a metal terminal embedded in the surface 120 of the dielectric substrate 100. A plurality of first power supply terminals 390 are provided corresponding to the respective first heating portions 331, but only one of them is shown in FIG. 1. The first power supply terminal 390 and the first bypass portion 350 located immediately above it are electrically connected via a via 302 provided inside the dielectric substrate 100. The via 302 is an electrical path provided by filling a hole extending perpendicular to the surface 110 with a metal such as tungsten.

[0032] The first bypass portion 350 is a thin, flat layer made of a metal material such as tungsten. The first bypass portion 350 is provided inside the dielectric substrate 100 at a height position closer to the surface 120 than the first heat generating portion 331. The first bypass portion 350 and the first heat generating portion 331 are electrically connected through a via 301 provided inside the dielectric substrate 100. The via 301 is an electrical path provided by filling a hole extending perpendicular to the surface 110 with a metal such as tungsten. In this way, the first heat generating portion 331 and the first power supply terminal 390 are electrically connected by the via 301, the first bypass portion 350, and the via 302.

[0033] One end of a bus bar 11 is connected to the first power supply terminal 390. Power is supplied from the outside to the first power supply terminal 390 via this bus bar 11. The bus bar 11 is inserted through a through hole 405 formed in the external heater unit 400 and a through hole 205 formed in the base plate 200.

[0034] 4 is a schematic perspective view showing the configuration of two regions HA, two first heat generating portions 331 routed through the regions HA, and first bypass portions 350 connected to the respective first heat generating portions 331. One of the two regions HA shown in FIG. 4 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 first heat generating portions 331 and the like shown in FIG. 4 are schematic and differ from the actual shapes.

[0035] A plurality of first bypass sections 350 are provided, each corresponding to a first power supply terminal 390. Only three of the plurality of first bypass sections 350 are shown in FIG. 4. Of the plurality of first bypass sections 350, those designated by the reference numeral "351" in FIG. 4 are arranged in positions that overlap only one region HA in top view. In other words, they are individually arranged in positions directly below the respective regions HA. The portions of the first bypass section 350 arranged in this manner are also referred to as "first bypass sections 351" below.

[0036] 4 is positioned so as to overlap both the region HA1 and the region HA2 in top view. The portion of the first bypass section 350 positioned in this manner will hereinafter also be referred to as the "first bypass section 352."

[0037] In the first heat generating portion 331 arranged in the region HA1, the pad portion 332 at one end of the first heat generating portion 331 is electrically connected to the first bypass portion 351 located directly below it by the via 301. The pad portion 333 at the other end of the first heat generating portion 331 is electrically connected to the first bypass portion 352 by the via 301.

[0038] The same applies to the first heat generating portion 331 arranged in region HA2, where a pad portion 332 at one end of the first heat generating portion 331 is electrically connected to a first bypass portion 351 located directly below it by a via 301. A pad portion 333 at the other end of the first heat generating portion 331 is electrically connected to the first bypass portion 352 by a via 301.

[0039] Vias 302 are connected to each of the first bypass portions 351 from below in Fig. 4. A voltage is individually applied to each of the vias 302 from an external DC power supply via a first power supply terminal 390 and a bus bar 11, not shown in Fig. 4. In addition, vias 302 are also connected to the first bypass portion 352 from below in Fig. 4. The vias 302 are grounded via the first power supply terminal 390 and the bus bar 11, not shown in Fig. 4. The DC power supply and the ground portion shown in Fig. 4 are part of a temperature adjustment control circuit that is connected to the electrostatic chuck 10 from outside.

[0040] As described above, in each of the first heat generating portions 331 provided in each region HA, one pad portion 332 is connected to an individual DC power supply via the first bypass portion 351, and the other pad portion 333 is grounded via the common first bypass portion 352. The other first heat generating portions 331 not shown in Fig. 4 are also connected to a DC power supply or the like in a similar configuration. With this configuration, it is possible to individually supply power to each of the multiple first heat generating portions 331 provided and adjust the amount of heat generated in each portion.

[0041] It is also possible to supply power to the first heat generating portion 331 directly from the first power supply terminal 390 without passing through the first bypass portion 350. However, by using a configuration in which power is supplied via the first bypass portion 350 as in this embodiment, it becomes possible to increase the degree of freedom in arranging the first power supply terminal 390 and to consolidate the first power supply terminals 390 that are grounded into one.

[0042] As described above, the entire built-in heater 300, including the first heat generating portion 331, is provided inside the dielectric substrate 100. The built-in heater 300 corresponds to the "first heater" in this embodiment. A configuration may also be adopted in which the portion of the built-in heater 300 other than the first heat generating portion 331 (for example, the first bypass portion 350) is provided outside the dielectric substrate 100.

[0043] Similar to the built-in heater 300, the external heater unit 400 generates heat upon receiving power from an external source and heats the dielectric substrate 100. However, the external heater unit 400 is entirely unitized and is provided outside the dielectric substrate 100. The shape of the external heater unit 400 is generally disk-shaped.

[0044] As shown in FIG. 1, the external heater unit 400 is sandwiched between the dielectric substrate 100 and the base plate 200 and bonded to each. The external heater unit 400 and the dielectric substrate 100 are bonded via a bonding layer 510, and the external heater unit 400 and the base plate 200 are bonded via a bonding layer 520. The bonding layers 510 and 520 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.

[0045] The specific configuration of the external heater unit 400 will be described. Fig. 5 shows a schematic exploded view of the configuration of the external heater unit 400. As shown in the figure, the external heater unit 400 has a support plate 410 (410A), an insulating layer 420, a heat generating layer 430, an insulating layer 440, a second bypass section 450, an insulating layer 460, a support plate 410 (410B), and a second power supply terminal 490.

[0046] The support plate 410 is a substantially disk-shaped member and is provided at each of the upper and lower ends of the external heater unit 400 in FIG. 5. The support plate 410 provided at the upper end in FIG. 5 is also referred to as the "support plate 410A" below. The support plate 410 provided at the lower end in FIG. 5 is also referred to as the "support plate 410B" below. The support plate 410A is a portion that is bonded to the dielectric substrate 100 via a bonding layer 510, and the support plate 410B is a portion that is bonded to the base plate 200 via a bonding layer 520.

[0047] The pair of support plates 410A, 410B are members for reinforcing the entire external heater unit 400 by sandwiching the entire heat generating layer 430, the second bypass section 450, etc. between them. In this embodiment, both support plates 410A, 410B are made of metal, but they may be made of other materials (e.g., insulating materials). Note that each of the members constituting the external heater unit 400, such as the support plate 410, has a plurality of through holes such as gas holes and lift pin holes, as well as the through hole 405 shown in FIG. 1, but these through holes are not shown in FIG. 5.

[0048] The insulating layer 420 is provided between the support plate 410A and the heat generating layer 430, and serves to electrically insulate them from each other. The insulating layer 420 also serves to physically bond them to each other. In this embodiment, the insulating layer 420 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 410A is made of an insulating material, the insulating layer 420 may be eliminated.

[0049] Heat generating layer 430 is a portion that generates heat when power is supplied from an external source. In Fig. 5, heat generating layer 430 is depicted as a single disk, but in reality, heat generating layer 430 is divided into multiple regions that do not overlap each other when viewed from above, and each region can be individually heated. The specific configuration of heat generating layer 430 will be described later.

[0050] The insulating layer 440 is provided between the heat generating layer 430 and the second bypass section 450, and serves to electrically insulate them from each other. The insulating layer 440 also serves to physically bond them to each other. In this embodiment, the insulating layer 440 is a polyimide film, but it may contain a component other than polyimide, or may be made of a material other than polyimide.

[0051] The second bypass section 450 is a layer for electrically connecting the second power supply terminal 490 and the heat generating layer 430 (specifically, between the second power supply terminal 490 and the second heat generating section 431). In FIG. 2, the second bypass section 450 is schematically depicted as a single disk, but in reality, the second bypass section 450 is divided into multiple sections. By providing the second bypass section 450 in the middle of the electric path connected to the heat generating layer 430, it becomes possible to adjust the position of the second power supply terminal 490, for example. A portion of each of the divided second bypass sections 450 is electrically connected to the heat generating layer 430.

[0052] The insulating layer 460 is provided between the second bypass section 450 and the support plate 410B, and serves to electrically insulate them from each other. The insulating layer 460 also serves to physically bond them to each other. In this embodiment, the insulating layer 460 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 410B is made of an insulating material, it is possible to eliminate the insulating layer 460.

[0053] 5 are laminated together, the entire assembly is pressurized and heated, thereby bonding the entire assembly together via the insulating layer 420, which is a polyimide film, and the like.

[0054] The second power supply terminal 490 is a part that receives, from the outside, the power required to generate heat in the heat generating layer 430. In this embodiment, the second power supply terminal 490 is formed as a long, thin, rod-shaped plug. One end of the second power supply terminal 490 is connected to the second bypass section 450 through openings (not shown) formed in the insulating layer 460 and the support plate 410B.

[0055] A plurality of second power supply terminals 490 are provided corresponding to the respective second heat generating portions 431, but only two of them are shown in Fig. 5. As shown in Fig. 1, through holes 206 are formed in the base plate 200 at positions corresponding to the second power supply terminals 490, and the second power supply terminals 490 are inserted through the through holes 206.

[0056] One end of a bus bar 12 is connected to the second power supply terminal 490. Power is supplied from the outside to the second power supply terminal 490 via this bus bar 12. The bus bar 12 is also inserted through the through hole 206.

[0057] The configuration of the heat generating layer 430 of the external heater unit 400 will now be described. As mentioned above, the heat generating layer 430 is divided into multiple regions, and each region can generate heat independently. Figure 6 shows an example of how the heat generating layer 430 is divided from a top view. In this example, the heat generating layer 430 is divided into a total of three regions HB.

[0058] The heat generating layer 430 is configured as linear second heat generating portions 431, which are individually routed in each region HB. That is, in this embodiment, a total of three second heat generating portions 431 are provided.

[0059] 7 shows an example of the second heat generating portion 431 routed in one region HB in top view. In each region HB, one linear second heat generating portion 431 is routed along a path that passes uniformly through almost the entire area. The second heat generating portion 431 is a portion that generates heat by receiving power from an external source.

[0060] Circular pad portions 432, 433 are formed on both ends of second heat generating portion 431. Second heat generating portion 431 and pad portions 432, 433 are formed, for example, by etching a thin metal foil. Note that the shape of second heat generating portion 431 shown in Fig. 6 is schematic and differs from the actual shape. The same applies to the positions of pad portions 432, 433.

[0061] 8 is a schematic perspective view showing the configuration of the two regions HB, the two second heat generating portions 431 routed therethrough, and the second bypass portions 450 connected to the respective second heat generating portions 431. For ease of explanation, the shape of each region HB is depicted in FIG. 8 as being different from its actual shape. The same applies to the shapes of the second heat generating portions 431 and the second bypass portions 450.

[0062] 8 will be referred to as "region HB1" below, and the other region HB will be referred to as "region HB2" below.

[0063] As described above, the second bypass section 450 is divided into multiple sections. In FIG. 8, only three of the multiple divided second bypass sections 450 are shown. Of the three divided second bypass sections 450, the one marked with the reference numeral "451" in FIG. 8 is arranged in a position overlapping only one region HB in top view. In other words, each of the three divided second bypass sections 450 is individually arranged in a position directly below each region HB. The portion of the second bypass section 450 arranged in this manner will also be referred to as the "second bypass section 451" below.

[0064] 8 is positioned so as to overlap both the region HB1 and the region HB2 in top view. The portion of the second bypass section 450 positioned in this manner is hereinafter also referred to as the "second bypass section 452."

[0065] In the second heat generating portion 431 arranged in the region HB1, a pad portion 432 at one end of the second heat generating portion 431 is electrically connected to the second bypass portion 451 located immediately below it. A pad portion 433 at the other end of the second heat generating portion 431 is electrically connected to the second bypass portion 452.

[0066] The same applies to the second heat generating portion 431 arranged in region HB2, where a pad portion 432 at one end of the second heat generating portion 431 is electrically connected to the second bypass portion 451 located directly below it. A pad portion 433 at the other end of the second heat generating portion 431 is electrically connected to the second bypass portion 452.

[0067] The electrical connection between the above-described components is achieved, for example, by welding the upper and lower layers together. To facilitate understanding of the configuration, in Fig. 8, each welded portion is depicted as a linear rod-shaped member (the portion designated by the reference numeral "401"). In the portion overlapping each welded portion in top view, an opening is formed in the insulating layer 340 between the heat generating layer 430 and the second bypass portion 450, and the heat generating layer 430 (specifically, the pad portions 432 and 433) and the second bypass portion 450 are directly connected through this opening.

[0068] The heat generating layer 430 and the second bypass section 450 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, an electrical path indicated by the reference numeral "401" in FIG. 8 is formed between the heat generating layer 430 and the second bypass section 450. This electrical path will hereinafter also be referred to as "electrical path 401."

[0069] 8 is connected to each of the second bypass portions 451. A voltage is individually applied to each of the second power supply terminals 490 from an external DC power supply via the bus bar 12. In addition, one end of the second power supply terminal 490 is also connected to the second bypass portion 452 from the bottom in FIG. 8. The second power supply terminal 490 is grounded via the bus bar 12. The DC power supply and the ground portion shown in FIG. 8 are part of a temperature adjustment control circuit that is externally connected to the electrostatic chuck 10.

[0070] As described above, in each of the second heat generating portions 431 provided in each region HB, one pad portion 432 is connected to an individual DC power supply via the second bypass portion 451, and the other pad portion 433 is grounded via the common second bypass portion 452. The other second heat generating portions 431 not shown in Fig. 8 are also connected to a DC power supply or the like in a similar configuration. With this configuration, it is possible to individually supply power to each of the multiple second heat generating portions 431 provided and adjust the amount of heat generated in each portion.

[0071] It is also possible to supply power to the second heat generating portion 431 directly from the second power supply terminal 490 without passing through the second bypass portion 450. However, by using a configuration in which power is supplied via the second bypass portion 450 as in this embodiment, it is possible to increase the degree of freedom in arranging the second power supply terminal 490 and to consolidate the second power supply terminals 490 that are grounded into one.

[0072] As described above, the entire external heater unit 400, including the second heat generating portion 431, is provided outside the dielectric substrate 100. The external heater unit 400 corresponds to the "second heater" in this embodiment.

[0073] The external heater unit 400 generates a larger amount of heat per unit area than the previously described built-in heater 300. The external heater unit 400 is intended to raise the temperature of the entire dielectric substrate 100 in a short period of time. The built-in heater 300 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 other words, the external heater unit 400 is used as a main heater for raising the temperature, and the built-in heater 300 is used as a sub-heater for adjustment. In this way, in this embodiment, two heaters are provided separately, each with its own role.

[0074] The electrostatic chuck 10 has a first heat generating portion 331, which has a small amount of heat generation per unit area and is provided inside the dielectric substrate 100. This allows the in-plane temperature distribution of the substrate W to be adjusted more precisely.

[0075] Like the first heating element 331 for precision adjustment, the second heating element 431 for temperature increase may also be provided inside the dielectric substrate 100. However, if the entire heater is provided inside the dielectric substrate 100, the dielectric substrate 100 will become too thick. If the dielectric substrate 100 becomes too thick, the impedance of the circuit including the dielectric substrate 100 will increase accordingly, which may cause problems such as an increased likelihood of discharge during processing of the substrate W.

[0076] Therefore, in this embodiment, as described above, the entire heater is not provided inside the dielectric substrate 100, but a part of it is provided outside the dielectric substrate 100 as an external heater unit 400. This configuration makes it possible to precisely adjust the in-plane temperature distribution of the substrate W while also reducing the thickness of the dielectric substrate 100. This also has the advantage of making it easier to manufacture the dielectric substrate 100 compared to when the entire heater is provided inside the dielectric substrate 100.

[0077] Furthermore, the second heat generating portion 431 for temperature increase has greater variations during manufacturing than the first heat generating portion 331 for adjustment, and it is often difficult to stably obtain consistent quality. For this reason, if the second heat generating portion 431 is built into the dielectric substrate 100, the yield of the dielectric substrate 100 may be reduced. If the second heat generating portion 431 is provided outside the dielectric substrate 100 as in this embodiment, there is also the advantage that the yield of the dielectric substrate 100 is improved.

[0078] In this embodiment, like the first heat generating portion 331, the first bypass portion 350 is also provided inside the dielectric substrate 100. The first bypass portion 350 is provided at a position between the first heat generating portion 331 and the second heat generating portion 431 in a direction perpendicular to the surface 110 that is the mounting surface, that is, at a height position closer to the surface 110 than the second heat generating portion 431. In this configuration, when arranging the first bypass portion 350, it is not necessary to consider interference with the electric path 401 connected to the second heat generating portion 431, and therefore the first bypass portion 350 can be arranged with a high degree of freedom.

[0079] The electrostatic chuck 10 according to this embodiment includes an internal heater 300 and an external heater unit 400 as heaters for heating the dielectric substrate 100. The electrostatic chuck 10 may be configured to further include a heater other than these as a heater for heating the dielectric substrate 100.

[0080] The second embodiment will be described below. Differences from the first embodiment will be mainly described below, and descriptions of commonalities with the first embodiment will be omitted as appropriate.

[0081] 9 is a schematic diagram illustrating the configuration of the electrostatic chuck 10 according to this embodiment, taken from the same perspective as in FIG. 1. In this embodiment, the external heater unit 400 does not include a second bypass portion 450, and one end of each second power supply terminal 490 is directly connected to pad portions 432 and 433 at the end of the second heat generating portion 431. With this configuration, the manufacturing cost of the external heater unit 400 can be reduced.

[0082] 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]

[0083] 10: Electrostatic chuck 100: Dielectric substrate 110: Face 300: Built-in heater 331: First heating section 350: First bypass section 390: First power supply terminal 400: External heater unit 431: Second heating section 450: Second bypass section 490: Second power supply terminal 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 first heater provided inside the dielectric substrate; a second heater provided outside the dielectric substrate.

2. the first heater includes a plurality of first heat generating portions that are conductors that are linearly routed inside the dielectric substrate, a plurality of first power supply terminals provided corresponding to the first heat generating portions; 2. The electrostatic chuck according to claim 1, further comprising: a plurality of first bypass portions electrically connecting the first heat generating portion and the first power supply terminal.

3. 3. The electrostatic chuck according to claim 2, wherein the first bypass portion is provided inside the dielectric substrate.

4. the second heater includes a plurality of second heat generating portions that are conductors that are linearly routed outside the dielectric substrate, 2. The electrostatic chuck according to claim 1, further comprising a plurality of second power supply terminals provided corresponding to the second heat generating portions, respectively.

5. 5. The electrostatic chuck according to claim 4, further comprising a plurality of second bypass portions electrically connecting the second heat generating portion and the second power supply terminal.

6. 6. The electrostatic chuck according to claim 5, wherein the second bypass portion is provided outside the dielectric substrate.

7. 5. The electrostatic chuck according to claim 4, wherein each of the second power supply terminals is directly connected to the second heat generating portion.

8. 2. The electrostatic chuck according to claim 1, wherein the amount of heat generated by the second heater per unit area is greater than the amount of heat generated by the first heater per unit area.

Images