TWI780384B - electrostatic chuck - Google Patents

Abstract

An electrostatic chuck is provided, which is characterized by comprising: a bottom plate; a ceramic dielectric substrate arranged on the aforementioned bottom plate and having a first main surface exposed to the outside, the aforementioned first main surface at least includes: a first region; adjacent to the aforementioned In the second area of the first area, the first area of the first main surface is provided with: a plurality of first grooves; at least one first gas introduction hole connected to at least one of the plurality of first grooves, the plurality of The first groove includes: a first boundary groove disposed closest to the first boundary between the first region and the second region and extending along the first boundary; at least one first boundary groove different from the first boundary groove A groove in an area is provided in the aforementioned second area of the aforementioned first main surface: a plurality of second grooves; at least one second gas introduction hole connected to at least one of the aforementioned plurality of second grooves, and the aforementioned plurality of second grooves The groove includes a second boundary groove disposed closest to the first boundary and extending along the first boundary, and the distance between the ends of the groove between the first boundary groove and the second boundary groove is greater than that between the first boundary groove and the adjacent The distance between the groove ends of the grooves in the first region of the first boundary groove is also small.

Description

Electrostatic chuck

Aspects of the present invention relate to electrostatic chucks.

An electrostatic chuck includes, for example, a ceramic dielectric substrate made of alumina, and electrodes arranged inside the ceramic dielectric substrate. Upon application of electric power to the electrodes, an electrostatic force is generated. An electrostatic chuck is used to attract objects such as silicon wafers by the generated electrostatic force. In such an electrostatic chuck, an inert gas such as helium (He) (hereinafter simply referred to as gas) flows between the surface of the ceramic dielectric substrate and the back surface of the object to control the temperature of the object.

For example, in devices that process substrates such as CVD (Chemical Vapor Deposition) devices, sputtering devices, ion implantation devices, and etching devices, there are The case where the temperature of the substrate rises. Therefore, in an electrostatic chuck used in such a device, gas is passed between the ceramic dielectric substrate and the substrate, and heat dissipation from the substrate is achieved by bringing the gas into contact with the substrate.

Furthermore, during the processing, a temperature distribution occurs within the surface of the object. In this case, as the pressure of the gas becomes higher, the heat dissipation amount from the object increases, so that the temperature of the object can be lowered. Therefore, the object-side surface of the ceramic dielectric substrate is divided into a plurality of regions, and by making the plurality The pressure change of the gas in each area controls the in-plane temperature of the object.

For example, in order to control the pressure of gas in each area, a technique of disposing a seal ring between each area has been proposed (for example, refer to Patent Document 1).

In this case, in order to control the pressure of the gas in each area, it is preferable to separate each area airtightly by a seal ring. However, in this way, particles generated during the wafer processing process tend to accumulate in the portion of the sealing ring, and there is a possibility that a defect or the like may occur in this portion.

A technique of providing a slight gap between the top of the seal ring and the object to control the pressure of the gas in each area has also been proposed (see Patent Document 2).

Even in this case, the problem that particles tend to accumulate in the ring-sealing portion has not yet been solved.

Therefore, development of a technology capable of effectively controlling the pressure of gas in each region and suppressing accumulation of fine particles in the ring-sealing portion is desired.

[Patent Document 1]: Japanese Patent Laid-Open No. 2011-119708

[Patent Document 2]: Japanese Patent Laid-Open No. 2012-129547

The first invention is an electrostatic chuck, which is characterized by comprising: a base plate; a ceramic dielectric substrate disposed on the base plate and having a first principal surface (principal surface) exposed to the outside, the first The main surface at least includes: a first area (area 101); a second area (area 102) adjacent to the first area, in the first area of the first main surface The field is provided with: a plurality of first grooves including grooves 14a, 14b; at least one first gas introduction hole (gas introduction hole 15) connected to at least one of the aforementioned plurality of first grooves, and the aforementioned plurality of first grooves include: the most Set close to the first boundary (boundary 102a) between the aforementioned first region and the aforementioned second region, the first boundary ditch extending along the aforementioned first boundary contains a groove 14a; at least one first boundary ditch different from the aforementioned first boundary ditch Groove (groove 14b) in a region, in the aforementioned second region of the aforementioned first main surface, there are: a plurality of second grooves containing grooves 14a, 14b; at least one second groove connected to at least one of the aforementioned plurality of second grooves; Gas introduction hole (gas introduction hole 15), the aforementioned plurality of second grooves include: the second boundary groove extending along the aforementioned first boundary is disposed closest to the aforementioned first boundary; and at least one of the second regions Different from the second boundary groove, the distance (L1) between the ends of the first boundary groove and the second boundary groove is larger than that in the first region adjacent to the first boundary groove. The distance between the groove ends (L2) between the grooves is also small, and the distance between the groove ends between the first boundary groove and the second boundary groove is smaller than that between the second boundary groove and the second region adjacent to the second boundary groove. The distance between the groove ends between the inner grooves is also small.

This electrostatic chuck does not have seal rings arranged between the regions to control the pressure of the gas in the regions as in the past. That is, when the object W is placed, an enclosed space is formed by the object W and the ceramic dielectric substrate (the first region and the second region). Therefore, the problem of particles accumulating in the ring-sealing portion can be solved. On the other hand, when only the seal ring is not provided, it becomes difficult to divide the gas pressure in each area, so that the controllability of the gas pressure decreases. Therefore, in the present invention, Not only the seal ring is removed, but also efforts are made so that the distance between the groove ends between the first boundary groove and the second boundary groove is larger than the distance between the groove ends between the first boundary groove and the grooves in the first region adjacent to the first boundary groove Still young.

Furthermore, according to this electrostatic chuck, since the area where the pressure of the gas changes can be reduced near the boundary between the areas, the area where the pressure of the gas becomes intended can be enlarged. Therefore, the problem of particle accumulation can be solved, and at the same time, the pressure of the gas in each region can be effectively controlled.

The second invention is an electrostatic chuck characterized in that in the first invention, the distance between the ends of the first boundary groove and the second boundary groove is larger than the distance between the ends of the grooves in the first region. The distance is still small.

According to this electrostatic chuck, the pressure of gas in each region can be more effectively controlled.

The third invention is an electrostatic chuck, characterized in that: in the first invention or the second invention, when projected onto a plane perpendicular to the first direction from the bottom plate to the ceramic dielectric substrate, the first gas introduced At least a part of the hole overlaps with the aforementioned first boundary groove.

In this electrostatic chuck, since the first boundary groove directly communicates with the first gas introduction hole, the gas control property is excellent. Therefore, the area where the pressure of the gas changes can be further reduced in the vicinity of the boundary between the areas.

The fourth invention is an electrostatic chuck, characterized in that: in any one of the first invention to the third invention, when projected onto a plane perpendicular to the first direction from the bottom plate to the ceramic dielectric substrate, , at least a part of the second gas introduction hole overlaps with the second boundary groove.

According to this electrostatic chuck, the area where the pressure of the gas changes can be further reduced near the boundary between the areas.

The fifth invention is an electrostatic chuck, characterized in that in any one of the first to fourth inventions, a line connecting the center of the first gas introduction hole and the center of the second gas introduction hole and the line connecting the center of the second gas introduction hole The angle formed by the first boundary is less than 90°.

According to this electrostatic chuck, it is possible to bring the boundary grooves closer to each other, and the area where the pressure of the gas changes can be reduced. Therefore, the region where the pressure of the intended gas can be increased can be increased.

The sixth invention is an electrostatic chuck, characterized in that in any one of the first to fourth inventions, a line connecting the center of the first gas introduction hole and the center of the second gas introduction hole The angle formed by the first boundaries is 90°.

According to this electrostatic chuck, it is easier to maintain the pressure of each area at the target pressure.

The seventh invention is an electrostatic chuck, which is characterized in that: in any one of the first invention to the sixth invention, it is further provided with a lift pin hole provided on the first main surface, and the lift pin hole is provided on the first main surface. The distance between the pin hole and the aforementioned first boundary groove is greater than the distance between the aforementioned ejector pin hole and the inner groove in the first region closest to the aforementioned ejector pin hole.

According to the electrostatic chuck, pressure variations in the area can be reduced.

The eighth invention is an electrostatic chuck, characterized in that: In any one of the first to seventh inventions, the first main surface at least includes: the first region; the second region located outside the first region; In the third area (area 103) of the aforementioned second area, the aforementioned plurality of second grooves are arranged closest to the second boundary between the aforementioned second area and the aforementioned third area, and the second groove extending along the aforementioned second boundary The outer boundary groove (groove 14a) is provided adjacent to the second boundary in the third region, and the third boundary groove extending along the second boundary includes the groove 14a. The second outer boundary groove and the third boundary A distance (L4) between groove ends between the grooves is greater than a distance (L1) between groove ends between the first boundary groove and the second boundary groove.

According to this electrostatic chuck, the area where the pressure of the gas changes can be further reduced near the boundary between the areas.

The ninth invention is an electrostatic chuck, which is characterized in that: in the eighth invention, it is further equipped with an outer seal (outer seal) provided so as to surround the periphery of the first main surface, at least a part of which is in contact with the object to be adsorbed, In a second direction perpendicular to the first direction from the bottom plate toward the ceramic dielectric substrate, the distance between the second boundary and the outer seal is greater than the distance between the first boundary and the second boundary Still young.

According to this electrostatic chuck, the area where the pressure of the gas changes can be further reduced near the boundary between the areas.

The tenth invention is an electrostatic chuck, characterized in that in the fourth invention or the fifth invention, the first gas introduction hole can be provided to supply gas to the first boundary groove, and the first gas introduction hole is provided with at least 2 indivual.

According to this electrostatic chuck, the gas can be reliably supplied to the first boundary groove containing groove 14a extending along the first boundary (boundary 102a).

The eleventh invention is an electrostatic chuck, wherein in the tenth invention, the second gas introduction hole is provided to supply gas to the second boundary groove, and at least two second gas introduction holes are provided.

According to this electrostatic chuck, gas can be reliably supplied to the second boundary groove containing groove 14a extending along the first boundary (boundary 102a).

The twelfth invention is an electrostatic chuck, which is characterized by comprising: a base plate; a ceramic dielectric substrate disposed on the base plate and having a first main surface exposed to the outside, and the first main surface at least includes: a first Region (region 101); the second region (region 102) adjacent to the aforementioned first region is provided with: a plurality of first grooves containing grooves 14a, 14b in the aforementioned first region of the aforementioned first main surface; At least one first gas introduction hole (gas introduction hole 15) connected to at least one groove, the aforementioned plurality of first grooves include: the first boundary (boundary 102a) closest to the aforementioned first region and the aforementioned second region It is provided that the first boundary ditch extending along the first boundary contains a ditch 14a; at least one ditch (ditch 14b) in the first region different from the first bridging ditch is in the aforementioned second region of the first main surface It is provided with: a plurality of second grooves containing grooves 14a, 14b; at least one second gas introduction hole (gas introduction hole 15) connected to at least one of the aforementioned plurality of second grooves, and the aforementioned plurality of second grooves include: the closest The aforementioned first border is provided, and the second border ditch extending along the aforementioned first border includes a ditch 14a; border with the aforementioned first The boundary ditch occupancy rate in the first range (range C1) between the boundary ditch and the aforementioned second boundary ditch is higher than that of the second range (range D) which includes the ditch in the first region and has the same shape and size as the first range. , D1), the occupancy ratio of the grooves in the area is still large, and the distance between the ends of the grooves between the first boundary groove and the second boundary groove is larger than that in the second region adjacent to the second boundary groove. The distance between the groove ends between the grooves is also small.

This electrostatic chuck does not have seal rings arranged between the regions to control the pressure of the gas in the regions as in the past. That is, when the object W is placed, one closed space is formed by the object W and the ceramic dielectric substrate (the first region and the second region). Therefore, the problem of particles accumulating in the ring-sealing portion can be solved. On the other hand, when only the seal ring is not provided, it becomes difficult to divide the gas pressure in each area, so that the controllability of the gas pressure decreases. Therefore, in the present invention, not only the sealing ring is removed, but also efforts are made so that the distance between the groove ends between the first boundary groove and the second boundary groove is smaller than that between the first boundary groove and the groove in the first region adjacent to the first boundary groove. The distance between the groove ends is also small.

Furthermore, according to this electrostatic chuck, since the area where the pressure of the gas changes can be reduced near the boundary between the areas, the area where the pressure of the gas becomes intended can be increased. Therefore, the problem of particle accumulation can be solved, and the pressure of the gas in each area can be effectively controlled

The thirteenth invention is an electrostatic chuck, characterized in that in the twelfth invention, the distance between the groove ends between the first boundary groove and the second boundary groove is smaller than the distance between the groove ends in the first region. The distance between departments is still small.

According to this electrostatic chuck, the pressure of gas in each region can be more effectively controlled.

The fourteenth invention is an electrostatic chuck, characterized in that in the twelfth invention or the thirteenth invention, when projected onto a plane perpendicular to the first direction from the bottom plate to the ceramic dielectric substrate, the above-mentioned first At least a part of a gas introduction hole overlaps with the first boundary groove.

In this electrostatic chuck, since the first boundary groove directly communicates with the first gas introduction hole, the gas control property is excellent. Therefore, the area where the pressure of the gas changes can be further reduced in the vicinity of the boundary between the areas.

The fifteenth invention is an electrostatic chuck, characterized in that: in any one of the twelfth invention to the fourteenth invention, when projected onto the first direction perpendicular to the first direction from the bottom plate to the ceramic dielectric substrate At least a part of the second gas introduction hole overlaps with the second boundary groove in a plane.

According to this electrostatic chuck, the area where the pressure of the gas changes can be further reduced near the boundary between the areas.

The sixteenth invention is an electrostatic chuck, characterized in that in any one of the twelfth to fifteenth inventions, the center of the first gas introduction hole and the center of the second gas introduction hole are connected. The angle formed by the line and the aforementioned first boundary is less than 90°.

According to this electrostatic chuck, it is possible to bring the boundary grooves closer to each other, and the area where the pressure of the gas changes can be reduced. Therefore, the region where the pressure of the intended gas can be increased can be increased.

The seventeenth invention is an electrostatic chuck, characterized in that: In any one of the twelfth invention to the fifteenth invention, the angle formed by the line connecting the center of the first gas introduction hole and the center of the second gas introduction hole and the first boundary is 90°. .

According to this electrostatic chuck, it is easier to maintain the pressure of each area at the target pressure.

The eighteenth invention is an electrostatic chuck, which is characterized in that: in any one of the twelfth invention to the seventeenth invention, it is further provided with a ejector pin hole provided on the first main surface, and the ejector pin The distance between the hole and the aforementioned first boundary groove is greater than the distance between the aforementioned ejector pin hole and the inner groove in the first region closest to the aforementioned ejector pin hole.

According to the electrostatic chuck, pressure variations in the area can be reduced.

The nineteenth invention is an electrostatic chuck, characterized in that: in any one of the twelfth invention to the eighteenth invention, the aforementioned first main surface at least includes: the aforementioned first region; The aforementioned second area on the outside; located outside the aforementioned second area, adjacent to the third area (area 103) of the aforementioned second area, the aforementioned plurality of second grooves include the area closest to the aforementioned second area and the aforementioned third area The second outer boundary ditch (groove 14a) is provided at the second boundary and extends along the second boundary, and the third boundary is provided adjacent to the second boundary and extends along the second boundary in the third region. The groove includes a groove 14a, has the aforementioned predetermined unit area, and has a boundary groove occupancy in a third range (range C2) including the second boundary, the second outer boundary groove, and the third boundary groove than the first range ( The in-region groove occupancy rate in the range C1) is still large.

According to the electrostatic chuck, the area-to-area boundary can be The area where the pressure change of the gas is reduced more nearby.

The twentieth invention is an electrostatic chuck, which is characterized in that: in the nineteenth invention, it is further provided to surround the periphery of the first main surface, at least a part of which is sealed except for being in contact with the object to be adsorbed, and In a second direction intersecting with the first direction from the bottom plate to the ceramic dielectric substrate, the distance between the second boundary and the outer seal is smaller than the distance between the first boundary and the second boundary .

According to this electrostatic chuck, the area where the pressure of the gas changes can be further reduced near the boundary between the areas.

The twenty-first invention is an electrostatic chuck, which is characterized by comprising: a bottom plate; a ceramic dielectric substrate disposed on the bottom plate and having a first main surface exposed to the outside, and the first main surface at least includes: the first main surface A region (region 101); the second region (region 102) adjacent to the aforementioned first region is provided with: a plurality of first grooves containing grooves 14a, 14b in the aforementioned first region of the aforementioned first main surface; At least one first gas introduction hole (gas introduction hole 15) connected to at least one of the first grooves, the plurality of first grooves include the first boundary (boundary 102a) closest to the first region and the second region It is provided that the first boundary groove extending along the aforementioned first boundary contains a groove 14a, and the aforementioned second region of the aforementioned first main surface is provided with: a plurality of second grooves including grooves 14a, 14b; At least one second gas introduction hole (gas introduction hole 15) connected to at least one of the grooves, the aforementioned plurality of second grooves include: a second boundary groove disposed closest to the aforementioned first boundary and extending along the aforementioned first boundary; and at least one ditch in the second region, different from the aforementioned second boundary ditch, the aforementioned first side The distance between the groove ends between the boundary groove and the second boundary groove containing groove 14a exceeds 0 mm and is 60 mm or less, and the distance between the groove ends between the first boundary groove and the second boundary groove is larger than the distance between the second boundary groove and the second boundary groove. The distance between the groove ends of the grooves in the second region adjacent to the second boundary groove is also small.

This electrostatic chuck does not have seal rings arranged between the regions to control the pressure of the gas in the regions as in the past. That is, when the object W is placed, one closed space is formed by the object W and the ceramic dielectric substrate (the first region and the second region). Therefore, the problem of particles accumulating in the ring-sealing portion can be solved. On the other hand, when only the seal ring is not provided, it becomes difficult to divide the gas pressure in each area, so that the controllability of the gas pressure decreases. Therefore, in the present invention, not only is the sealing ring removed, but also efforts are made so that the distance between the groove ends between the first boundary groove and the second boundary groove exceeds 0 mm and is 60 mm or less.

Furthermore, according to this electrostatic chuck, since the area where the pressure of the gas changes can be reduced near the boundary between the areas, the area where the pressure of the gas becomes intended can be enlarged. Therefore, the problem of particle accumulation can be solved, and at the same time, the pressure of the gas in each region can be effectively controlled.

The twenty-second invention is an electrostatic chuck, wherein in the twenty-first invention, the distance between the ends of the first boundary groove and the second boundary groove exceeds 0 mm and is 20 mm or less.

According to this electrostatic chuck, the pressure of gas in each region can be more effectively controlled.

The twenty-third invention is an electrostatic chuck, which is characterized in that: in the twenty-first invention or the twenty-second invention, the When the bottom plate faces the plane of the ceramic dielectric substrate in the first direction, at least a part of the first gas introduction hole overlaps with the first boundary groove.

In this electrostatic chuck, since the first boundary groove directly communicates with the first gas introduction hole, the gas control property is excellent. Therefore, the area where the pressure of the gas changes can be further reduced in the vicinity of the boundary between the areas.

The twenty-fourth invention is an electrostatic chuck, characterized in that: in any one of the twenty-first invention to the twenty-third invention, when projected to a direction perpendicular to the direction from the bottom plate to the ceramic dielectric substrate At least a part of the second gas introduction hole overlaps with the second boundary groove in the plane of the first direction.

According to this electrostatic chuck, the area where the pressure of the gas changes can be further reduced near the boundary between the areas.

The twenty-fifth invention is an electrostatic chuck, characterized in that in any one of the twenty-first to twenty-fourth inventions, the center of the first gas introduction hole and the second gas introduction hole are connected. The angle formed by the line of the center of and the aforementioned first boundary is less than 90°.

According to this electrostatic chuck, it is possible to bring the boundary grooves closer to each other, and the area where the pressure of the gas changes can be reduced. Therefore, the region where the pressure of the intended gas can be increased can be increased.

The twenty-sixth invention is an electrostatic chuck characterized in that in any one of the twenty-first to twenty-fourth inventions, the center of the first gas introduction hole and the second gas introduction hole are connected. The angle formed by the line of the center of and the aforementioned first boundary is 90°.

According to the electrostatic chuck, it is easier to keep the pressure in each area Stay on target pressure.

The twenty-seventh invention is an electrostatic chuck, characterized in that: in any one of the twenty-first invention to the twenty-sixth invention, the aforementioned plurality of first grooves further have: different from the aforementioned first boundary grooves At least one groove (groove 14b) in the first region; the ejector pin hole arranged on the aforementioned first main surface, the distance between the aforementioned ejector pin hole and the aforementioned first boundary groove is shorter than the aforementioned ejector pin hole and the closest The distance between the grooves in the aforementioned first region of the aforementioned ejector pin hole is also larger.

According to the electrostatic chuck, pressure variations in the area can be reduced.

1: Electrostatic chuck

11: Ceramic dielectric substrate

11a: first major surface

11b: Second major surface

12: Electrode

13: Dots

14a~14c: ditch

15: Gas inlet hole

16: Ejection pin hole

17: Outer seal

20: Connecting part

50: Bottom plate

50a: upper part

50b: lower part

51: input channel

52: output channel

53: gas supply channel

53a: Boring part

55: Connection Road

70: second porous part

90: the first porous part

100a, 100b1, 100b2, 101~104: area

101a~103a: Boundary

200: processing device

210: power supply

220: Medium supply department

221: storage department

222: Control valve

223: discharge part

230: Supply Department

231: Gas supply unit

232: Gas Control Department

240: reaction chamber

L1~L4, L21~L24: Distance between groove ends

P1, P2, P3: gas pressure

W: object

FIG. 1 is a schematic cross-sectional view illustrating an electrostatic chuck related to the embodiment of this embodiment.

FIG. 2 is a schematic cross-sectional view for illustrating a ceramic dielectric substrate, electrodes, and a first porous portion.

Fig. 3(a) is a schematic cross-sectional view illustrating the arrangement of grooves and the arrangement of gas introduction holes in a comparative example. (b) is a schematic cross-sectional view illustrating an example of the arrangement of grooves and the arrangement of gas introduction holes related to the present embodiment.

Fig. 4 is a graph (graph) of the pressure of the region and the pressure of the boundary between the region and the region obtained by simulation.

Figure 5 is a graph illustrating the effect of boundary trench spacing.

Fig. 6(a) is a graph used to illustrate the effect of boundary groove spacing by [slope deviation rate]. (b) is a graph used to illustrate [slope deviation rate].

Fig. 7 is an enlarged view of part H in Fig. 6(a).

Fig. 8 is a graph illustrating the effect of the number of second grooves (grooves 14a, 14b).

Fig. 9(a) is a schematic cross-sectional view for illustrating the arrangement of gas introduction holes. (b) is a schematic cross-sectional view illustrating the arrangement of gas introduction holes related to another embodiment.

Fig. 10(a) and (b) are graphs of the pressure of the region and the pressure of the boundary between the region and the region obtained by simulation.

Fig. 11 is a schematic plan view of a ceramic dielectric substrate according to another embodiment.

Fig. 12(a) is a schematic plan view illustrating the arrangement of grooves in a comparative example. (b) is a schematic plan view for illustrating the arrangement of grooves.

Fig. 13 is a graph illustrating the pressure variation on the center of the substrate.

14(a)~(c) are schematic diagrams for illustrating the form of the groove 14c.

Fig. 15 is a schematic plan view of a ceramic dielectric substrate according to another embodiment.

FIG. 16 is a schematic diagram for illustrating an example of a processing device according to the embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in each drawing, the same reference numerals are assigned to the same constituent elements, and detailed descriptions thereof are appropriately omitted.

In addition, in each figure, from the bottom plate 50 toward the ceramic dielectric substrate The direction of 11 is taken as the Z direction, one of the directions approximately perpendicular to the Z direction is taken as the Y direction, and the direction slightly perpendicular to the Z direction and the Y direction is taken as the X direction.

(Electrostatic Chuck)

FIG. 1 is a schematic cross-sectional view illustrating an electrostatic chuck 1 according to the present embodiment.

FIG. 2 is a schematic cross-sectional view for illustrating the ceramic dielectric substrate 11 , the electrode 12 and the first porous portion 90 .

As shown in FIG. 1 , a ceramic dielectric substrate 11 , an electrode 12 , a first porous portion 90 , a bottom plate 50 , and a second porous portion 70 can be disposed on the electrostatic chuck 1 .

As shown in FIGS. 1 and 2 , the ceramic dielectric substrate 11 can be, for example, a plate-shaped member using sintered ceramics. For example, the ceramic dielectric substrate 11 may include aluminum oxide (Al ₂ O ₃ ). For example, the ceramic dielectric substrate 11 can be formed using high-purity alumina. The concentration of alumina in the ceramic dielectric substrate 11 can be, for example, not less than 99 atomic percent (atomic%) and not more than 100 atomic%. If high-purity alumina is used, the plasma resistance of the ceramic dielectric substrate 11 can be improved. The porosity of the ceramic dielectric substrate 11 can be, for example, 1% or less. The density of the ceramic dielectric substrate 11 can be, for example, 4.2 g/cm ³ .

The ceramic dielectric substrate 11 has a first main surface 11a on which an object W to be adsorbed is placed, and a second main surface 11b on the opposite side to the first main surface 11a. The first main surface 11 a is a surface exposed to the outside of the electrostatic chuck 1 . The object W can be, for example, a semiconductor substrate such as a silicon wafer or a glass substrate.

A plurality of dots 13 are provided on the first main surface 11 a of the ceramic dielectric substrate 11 . The object W is placed on the plurality of points 13 and supported by the plurality of points 13 . If a plurality of points 13 are set, the A space is formed between the back surface of the object W of the electrostatic chuck 1 and the first main surface 11 a. By appropriately selecting the height and number of dots 13 , the area ratio and shape of dots 13 , for example, particles adhering to the object W can be brought into an appropriate state. For example, the height (dimension in the Z direction) of the plurality of dots 13 can be in the range of 1 μm to 100 μm, preferably in the range of 1 μm to 30 μm, more preferably in the range of 5 μm to 15 μm.

A plurality of grooves 14 a, 14 b are provided on the first main surface 11 a of the ceramic dielectric substrate 11 . The plurality of grooves 14 a and 14 b are opened on the first main surface 11 a side of the ceramic dielectric substrate 11 . The width of the groove 14 a (the dimension in the X direction or the Y direction) can be, for example, 0.1 mm to 2.0 mm, preferably 0.1 mm to 1.0 mm, more preferably 0.2 mm to 0.5 mm. The depth (dimension in the Z direction) of the groove 14 a can be, for example, 10 μm to 300 μm, preferably 10 μm to 200 μm, more preferably 50 μm to 150 μm. The width (dimension in the X direction or the Y direction) of the groove 14b can be 0.1 mm or more and 1.0 mm or less, for example. The depth (dimension in the Z direction) of the groove 14b can be, for example, 0.1 mm to 2.0 mm, preferably 0.1 mm to 1.0 mm, more preferably 0.2 mm to 0.5 mm.

A plurality of gas introduction holes 15 are provided in the ceramic dielectric substrate 11 . One end of each of the plurality of gas introduction holes 15 may be connected to the groove 14a. The other end of each of the plurality of gas introduction holes 15 can pass through the first porous portion 90 and be connected to the gas supply channel 53 described later. The gas introduction holes 15 are provided from the second main surface 11b to the first main surface 11a. That is, the gas introduction hole 15 extends in the Z direction between the second main surface 11 b side and the first main surface 11 a side, and penetrates through the ceramic dielectric substrate 11 . gas The diameter of the introduction hole 15 can be, for example, not less than 0.05 mm and not more than 0.5 mm.

In addition, details about the plurality of grooves 14a, 14b and the plurality of gas introduction holes 15 will be described later.

The electrodes 12 are arranged inside the ceramic dielectric substrate 11 . The electrode 12 is disposed between the first main surface 11 a and the second main surface 11 b of the ceramic dielectric substrate 11 .

The shape of the electrode 12 can be, for example, a film shape along the first main surface 11 a and the second main surface 11 b of the ceramic dielectric substrate 11 . The electrode 12 is an adsorption electrode for adsorbing and holding the object W to be held. The electrodes 12 may be either unipolar or bipolar. The electrode 12 illustrated in FIG. 1 is a bipolar type, and two electrodes 12 are arranged on the same surface.

A connection portion 20 is arranged on the electrode 12 . The electrodes 12 and the connection part 20 can be formed of a conductive material such as metal. An end portion of the connection portion 20 on the side opposite to the electrode 12 may be exposed on the second main surface 11 b side of the ceramic dielectric substrate 11 . The connecting portion 20 can be, for example, a via (solid type) or a via hole (hollow type) that is connected to the electrode 12 . The connecting portion 20 may be a metal terminal connected by an appropriate method such as brazing.

The electrode 12 is electrically connected to a power source 210 through the connecting portion 20 . When a predetermined voltage is applied to the electrode 12 , charges can be generated in the region of the electrode 12 on the first main surface 11 a side. Therefore, the object W is attracted and held on the first main surface 11 a side of the ceramic dielectric substrate 11 by electrostatic force.

The first porous portion 90 is arranged inside the ceramic dielectric substrate 11 . For example, the first porous portion 90 can be arranged between the bottom plate 50 and the first main surface 11a of the ceramic dielectric substrate 11 in the Z direction, and can be connected to the gas The position where the supply path 53 faces. For example, the first porous portion 90 may be disposed in the gas introduction hole 15 of the ceramic dielectric substrate 11 . For example, the first porous portion 90 is inserted into a part of the gas introduction hole 15 .

In the case of the first porous portion 90 exemplified in FIGS. 1 and 2 , the first porous portion 90 is arranged in a portion of the gas introduction hole 15 on the second main surface 11 b side. One end of the first porous portion 90 is exposed on the second main surface 11 b of the ceramic dielectric substrate 11 . The other end of the first porous portion 90 is located between the first main surface 11a and the second main surface 11b. In addition, the other end portion of the first porous portion 90 may be exposed on the bottom surface of the groove 14a. Furthermore, both end portions of the first porous portion 90 may be located between the first main surface 11 a and the second main surface 11 b.

The material of the first porous portion 90 can be, for example, insulating ceramics. The first porous portion 90 includes, for example, at least one of aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), and yttrium oxide (Y ₂ O ₃ ). In this way, it can be regarded as the first porous portion 90 having a high withstand voltage and high rigidity.

In this case, the alumina purity of the ceramic dielectric substrate 11 can be made higher than the alumina purity of the first porous portion 90 . In this way, performance such as plasma resistance of the electrostatic chuck 1 can be ensured, and mechanical strength (mechanical strength) of the first porous portion 90 can be secured. As an example, by making the first porous part 90 contain a small amount of additives, the sintering of the first porous part 90 is promoted, and it becomes possible to control pores and ensure mechanical strength.

The purity of ceramics such as alumina can be determined by X-ray fluorescence analysis (X-ray fluorescence analysis), ICP-AES method (Inductively Coupled Plasma-Atomic Emission Spectrometry: Inductively Coupled Plasma-Atomic Emission Spectrometry) etc. for measurement.

As shown in FIG. 1 , the bottom plate 50 supports, for example, the ceramic dielectric substrate 11 . The ceramic dielectric substrate 11 may, for example, be followed on the bottom plate 50 . The adhesive can be, for example, silicon adhesive.

The bottom plate 50 is made of metal, for example. The base plate 50 is, for example, divided into an upper part 50a and a lower part 50b made of aluminum, between which a connecting channel 55 is arranged. One end side of the connection path 55 is connected to the input path 51 , and the other end side of the connection path 55 is connected to the output path 52 .

The bottom plate 50 also plays a role of adjusting the temperature of the ceramic dielectric substrate 11 . For example, when cooling the ceramic dielectric substrate 11 , a cooling medium (cooling medium) flows in from the input channel 51 and flows out from the output channel 52 through the connection channel 55 . Accordingly, the ceramic dielectric substrate 11 mounted thereon can be cooled by the cooling medium absorbing the heat of the bottom plate 50 . In addition, in the case of keeping the ceramic dielectric substrate 11 warm, a heat keeping medium may flow into the connecting path 55 . If the temperature of the ceramic dielectric substrate 11 can be controlled, it becomes easy to control the temperature of the object W adsorbed and held on the ceramic dielectric substrate 11 .

Gas is supplied to the plurality of grooves 14a, 14b. When the supplied gas contacts the object W, the temperature of the object W is controlled. In this case, if the temperature of the bottom plate 50 can be controlled, the width of temperature control by the gas supplied to the grooves 14a and 14b can be reduced. For example, the temperature of the object W can be roughly controlled by the bottom plate 50, and the temperature of the object W can be controlled by the gas supplied to the grooves 14a, 14b. body precisely controls the temperature of the object W.

A plurality of gas supply passages 53 may be provided on the bottom plate 50 . The gas supply passage 53 can be provided so as to penetrate through the bottom plate 50 . The gas supply passage 53 may not pass through the bottom plate 50 , but may be provided on the ceramic dielectric substrate 11 side by branching off from another gas supply passage 53 midway.

The gas supply channel 53 is connected to the gas introduction hole 15 . That is, the gas flowing into the gas supply channel 53 flows into the gas introduction hole 15 after passing through the gas supply channel 53 .

The gas flowing into the gas introduction hole 15 flows into the groove 14 a connecting the gas introduction hole 15 after passing through the gas introduction hole 15 . Accordingly, the object W can be directly cooled by the gas.

The second porous part 70 may be disposed between the first porous part 90 and the gas supply channel 53 in the Z direction. For example, the second porous portion 70 is embedded in the end surface of the bottom plate 50 on the ceramic dielectric substrate 11 side. As shown in FIG. 1 , for example, a counterbore portion 53 a is provided on the end surface of the base plate 50 on the ceramic dielectric substrate 11 side, and the second porous portion 70 can be fitted into the counterbore portion 53 a. The bore portion 53 a is connected to the gas supply path 53 . The second porous portion 70 can be arranged to face the first porous portion 90 .

Next, the plurality of grooves 14a, 14b and the plurality of gas introduction holes 15 will be further described.

As described above, the temperature of the object W can be controlled by the gas supplied to the plurality of grooves 14a, 14b. During the processing of the object W, temperature distribution may occur within the surface of the object W. For example, a region with a low temperature or a region with a high temperature may be generated within the surface of the object W. In this case, if the The pressure of the gas in the area with high contact temperature is higher than the pressure of the gas in the area with low contact temperature, and the amount of heat dissipation from the area with high temperature increases, so it is possible to control the temperature of the object W while suppressing the temperature of the object W. produces a temperature distribution within the plane.

For example, the in-plane temperature of the object W can be controlled by dividing the first main surface 11a side of the ceramic dielectric substrate 11 into a plurality of regions and changing the pressure of the gas supplied to the plurality of regions. In this case, in order to control the pressure of the gas in each area, a seal ring may be provided between each area to isolate each area. In this example, the top of the seal ring is brought into contact with the surface of the object W on the first main surface 11 a side. In this way, since the flow of gas between regions can be substantially eliminated, the pressure of gas in each region can be effectively controlled.

However, if the seal ring is provided, particles generated during the wafer processing process tend to accumulate in the seal ring portion, and there is a possibility that a defect or the like may occur in this portion.

Therefore, in the present invention, no seal ring is provided for dividing the area, but the arrangement of the grooves 14a, 14b is worked out. That is to say, when the object W is placed, a closed space is formed by the object W and the ceramic dielectric substrate 11 (for example, the region 101 and the region 102 ). According to the present invention, the pressure control in the zone can be effectively carried out despite the absence of a sealing ring.

Furthermore, in the present invention, substantially no sealing ring is provided, as long as the pressure of the gas in each region can be effectively controlled, and partial or partial disposition of the sealing ring is not hindered. That is to say, as long as there is substantially no sealing ring and the effect of effectively controlling the pressure of the gas in each region is achieved, partly or It is also possible to provide sealing rings locally.

FIG. 3( a ) is a schematic cross-sectional view illustrating the arrangement of grooves 14 and the arrangement of gas introduction holes 15 in a comparative example.

In FIG. 3( a ), grooves 14 are provided at regular intervals in the X direction. That is, the distance L23 between the groove ends in the X direction is made the same.

In addition, in this specification, the distance between groove ends refers to the inner wall of one groove on the other side of the groove and the inner wall of the other groove on the other side of the groove when there are two adjacent grooves. the shortest distance between. In this case, when the distance between the groove ends of the two grooves varies, the shortest distance can be regarded as the distance between the groove ends.

Furthermore, in the X direction, the region 100a and the region 100b1, and the region 100a and the region 100b2 are adjacent to each other. In the configuration illustrated in FIG. 3( a ), the gas introduction holes 15 are connected to the two grooves 14 provided across the boundary between the region 100 a and the region 100 b 1 .

And, let the pressure of the gas supplied to the groove 14 provided in the region 100a be P1, the pressure of the gas supplied to the groove 14 provided in the region 100b1 be P2, and let the pressure of the gas supplied to the groove 14 provided in the region 100b2 be P1. for P3.

Fig. 3(b) is a schematic cross-sectional view illustrating an example of the arrangement of the grooves 14a and 14b and the arrangement of the gas introduction holes 15 according to the present embodiment. The groove 14a is a boundary groove provided to sandwich the boundary between different regions, and the groove 14b is a groove in a region other than the groove 14a provided in the region.

In FIG. 3( b ), the groove ends of the two grooves 14a (boundary grooves) provided across the boundary between the region 100a and the regions 100b1 and 100b2 in the X direction The distance between the boundary grooves (interval of the boundary groove) is L21, and the distance between the groove ends of the groove 14a (the boundary groove) and the groove 14b (the groove in the region) other than the groove 14a in the region 100a adjacent to the boundary groove 14a (the groove in the region) is L21. interval) is L22. In this case, L21<L22. Furthermore, the distance between the groove 14a (boundary groove) and the groove ends of the grooves 14b adjacent to the boundary groove 14a other than the grooves 14a provided in the regions 100b1 and 100b2 is L24.

Also, let the pressure of the gas supplied to the groove 14a provided in the region 100a through the gas introduction hole 15 be P1, and let the pressure of the gas supplied to the groove 14a provided in the region 100b1 be P2.

Fig. 4 is a graph showing the pressure in the region 100a, the pressures in the regions 100b1 and 100b2, and the pressure at the boundary between the region 100a and the regions 100b1 and 100b2 obtained by simulation. In the simulation, the object W supported by the points 13 is formed above the first main surface 11 a of the ceramic dielectric substrate 11 .

A in FIG. 4 is an example in which the arrangement of the grooves 14, the arrangement of the gas introduction holes 15, and the distance between the boundary grooves and the distance between the grooves in the region are equal to those illustrated in FIG. 3(a).

B in FIG. 4 is an example in which the arrangement of the grooves 14a and 14b, the arrangement of the gas introduction holes 15, and the boundary groove spacing are smaller than the groove spacing in the region illustrated in FIG. 3(b). In either case, no sealing rings are provided between the regions.

In addition, in the simulation, P1=3×P2, the distance L21 between the groove ends was 5 mm, the distance L22 between the groove ends was 20 mm, and the distance L23 between the groove ends was 15 mm. The size of the region 100 a in the X direction is 50 mm.

It can be seen from FIG. 4 that, in the case where the interval between the boundary grooves and the interval between the grooves in the region are equal (case A), in the region 100a and the regions 100b1 and 100b2 Near the boundary of , the region where the pressure of the gas changes becomes larger. On the other hand, in the case where the interval between the boundary grooves is smaller than the interval between the grooves in the region (case B), the region where the pressure of the gas can be changed near the boundary between the region 100a and the regions 100b1 and 100b2 is narrower than that in the case of A. small. That is, in any one of the region 100a, the regions 100b1, and 100b2, the pressure of the intended gas can be increased, and the uniformity of the gas pressure in the region can be improved.

As mentioned above, by concentrating on the arrangement of the grooves 14a and 14b, the temperature of the object W can be controlled by the pressure of the gas even when no seal ring is provided between the regions. Therefore, if the uniformity of the gas pressure in the region can be improved, the temperature of the object W in the portion corresponding to the region can be controlled more effectively. Furthermore, it is possible to suppress the occurrence of in-plane distribution in the temperature of the object W.

Furthermore, according to the knowledge obtained by the present inventors, if at least one of the two boundary grooves 14a provided across the boundary is connected to the gas introduction hole 15, the above-mentioned effect can be obtained, so it is preferable.

In this case, since there is a gap of only the height of point 13 between the first main surface 11a and the object W, the gas supplied to the groove 14a connected to the gas introduction hole 15 passes through the gap and is supplied to the groove 14b or other channels. The ditch 14a. That is, in each region, the gas is supplied to the space formed between the back surface of the object W and the first main surface 11a including the grooves 14a and 14b.

And, as illustrated in Fig. 3 (b), when the gas introduction holes 15 are connected to each of the two grooves 14a provided across the boundary, the change of the gas pressure on the boundary of the region can be made more significant, And, can It is more preferable to control the temperature of the object W more effectively. Furthermore, it is possible to more effectively suppress the occurrence of in-plane distribution in the temperature of the object W.

Figure 5 is a graph illustrating the effect of boundary trench spacing.

The boundary groove interval on the horizontal axis is the distance between the groove ends of two grooves (boundary grooves) provided across the boundary of the adjacent region. The effect of the boundary groove spacing is the effect of the boundary groove spacing itself. For example, the distance L23 illustrated in FIG. 3( a ) and the distance L21 illustrated in FIG. 3( b ) can be applied.

The deviation rate on the vertical axis indicates how much the average pressure in each region deviates from the set pressure (intended pressure). When the deviation rate becomes larger, it means that the difference between the average pressure in each region and the intended pressure becomes larger.

Figure 5 shows, for example, that the pressure P1 in the area 100a in Figure 3(a) and (b) is 20 Torr (2666.4Pa), and the pressure P3 in the area 100b2 is 60 Torr (7999.2Pa), and the deviation rate is obtained by simulation.

It can be seen from FIG. 5 that if the boundary groove interval of the distance between the groove ends of the boundary groove exceeds 0 mm and is less than 60 mm, preferably more than 0 mm and less than 20 mm, the deviation rate increases approximately linearly. If the boundary groove interval exceeds 60 mm, the deviation rate increases exponentially. This means that if the interval between the boundary grooves is 60 mm or less, preferably 20 mm or less, the increase in the deviation rate can be suppressed, and the average pressure in each region can approach the intended pressure.

As mentioned above, because the effect of the boundary groove spacing is the effect of the boundary groove spacing itself, if the arrangement of the aforementioned grooves 14a, 14b is worked hard, and the aforementioned arrangement of the gas introduction hole 15 (the gas introduction hole 15 is connected to the boundary groove) , the proper combination of the grooves 14c described later can more effectively control the gas flow in each area. At the same time, it can effectively suppress the accumulation of particles on the sealing ring part.

Fig. 6(a) is a graph used to illustrate the effect of boundary groove spacing by [slope deviation rate].

Fig. 6(b) is a graph for explaining [slope deviation rate].

Fig. 7 is an enlarged view of part H in Fig. 6(a).

If the pressure in the first region and the pressure in the second region are ideally cut off, the pressure distribution on the first boundary between the first region and the second region is shown in Figure 6(b), which can be considered to be on a straight line distribution (varies linearly). Therefore, the effect of the boundary groove spacing can be evaluated by arithmetically calculating the slope from the analytically obtained pressure distribution between regions, and obtaining the deviation rate (slope deviation rate) from the ideal slope.

From FIG. 6( a ), it can be seen that when the boundary groove interval of the distance between the groove ends of the boundary groove exceeds 0 mm and is 60 mm or less, the slope deviation rate increases approximately linearly. If the boundary groove interval exceeds 60mm, the slope deviation rate increases exponentially. This means that if the boundary groove interval is 60 mm or less, the increase in the gradient deviation rate can be suppressed, and the average pressure in each region will approach the intended pressure.

Furthermore, it can be seen from FIG. 7 that if the boundary groove interval between the groove ends of the boundary groove exceeds 0 mm and is 20 mm or less, the slope deviation rate can be made closer to linear. This means that if the boundary groove interval is 20 mm or less, the increase in the slope deviation rate can be suppressed more, and the average pressure in each region will be closer to the intended pressure.

Fig. 8 is a graph illustrating the effect of the number of second grooves (radial grooves).

It can be seen from FIG. 8 that if at least two second grooves are provided in the second region, the deviation rate can be significantly reduced. That is, the pressure of the first boundary (boundary 102a) between the first region (region 101) and the second region (region 102) can be made close to the average value of the pressure of the first region and the pressure of the second region. Therefore, it is easier to maintain the pressure in each zone at the target pressure.

According to the knowledge obtained by the present inventors, if the occupancy rate of the boundary groove is larger than the occupancy rate of the inner groove, the effect illustrated in FIG. 4 can be obtained. That is, if the boundary groove occupancy is larger than the intra-region groove occupancy, the area where the gas pressure changes can be reduced near the boundary. Therefore, the temperature of the object W can be effectively controlled because the region where the pressure of the intended gas can be increased can be increased. Furthermore, it is possible to suppress the occurrence of in-plane distribution in the temperature of the object W.

FIG. 9( a ) is a schematic cross-sectional view for illustrating the arrangement of the gas introduction holes 15 .

In FIG. 9( a ), in the X direction, the region 100a and the region 100b1 and the region 100a and the region 100b2 are adjacent to each other. Furthermore, two grooves 14a (boundary grooves) are provided across the boundary between the region 100a and the regions 100b1 and 100b2 in the X direction. Further, grooves 14b (in-region grooves) are provided inside the region 100a and inside the regions 100b1 and 100b2. In the region 100a, the gas introduction hole 15 is connected to the groove 14a on the region 100b1 side, and the gas introduction hole 15 is not connected to the groove 14a on the region 100b2 side. In the region 100b1, the gas introduction hole 15 is connected to the groove 14a on the side of the region 100a. In the region 100b2, the gas introduction hole 15 is connected to the groove 14a on the side of the region 100a. That is, in the region 100a, the gas introduction hole 15 is connected to only one groove 14a.

In addition, let the pressure of the gas supplied to the groove 14a provided in the region 100a be P1, and let the pressure of the gas supplied to the groove 14a provided in the regions 100b1 and 100b2 be P2.

Fig. 9(b) is a schematic cross-sectional view for illustrating the arrangement of gas introduction holes 15 related to another embodiment.

In FIG. 9(b), in the region 100a, the gas introduction hole 15 is connected to the groove 14a on the region 100b1 side and the groove 14a on the region 100b2 side.

In addition, let the pressure of the gas supplied to the groove 14a provided in the region 100a be P1, and let the pressure of the gas supplied to the groove 14a provided in the regions 100b1 and 100b2 be P2.

Fig. 10(a) and (b) are graphs of the pressure in the region 100a, the pressure in the regions 100b1 and 100b2, and the pressure at the boundary between the region 100a and the regions 100b1 and 100b2 obtained by simulation. In the simulation, the object W supported by the points 13 is formed above the first main surface 11 a of the ceramic dielectric substrate 11 .

Fig. 10(a) is the situation of Fig. 9(a).

Fig. 10(b) is the situation of Fig. 9(b).

Furthermore, assuming that P1=3×P2, the size of the region 100 a in the X direction is 50 mm.

As shown in Fig. 9(a), since the gas introduction hole 15 is not connected to the groove 14a in the region 100b2 side of the region 100a, it can be seen from Fig. 9(a) that the region where the pressure of the gas changes near the boundary get bigger. Therefore, the area where the pressure of the intended gas becomes smaller becomes smaller.

On the other hand, in the region 100b1 side of the region 100a, in the groove 14a Since the gas introduction hole 15 is connected, it can be seen from FIG. 10( a ) that the area where the pressure of the gas changes becomes smaller near the boundary. Therefore, the region where the pressure of the intended gas can be increased can be increased.

10(b), it is more preferable to connect the gas introduction holes 15 between the two grooves 14a provided across the boundary, so that the area where the pressure of the intended gas can be increased can be increased.

As mentioned above, the temperature of the object W can be controlled by the pressure of the gas. Therefore, if the region where the pressure of the intended gas can be increased, the temperature of the object W can be effectively controlled. Furthermore, it is possible to suppress the occurrence of in-plane distribution in the temperature of the object W.

As described above, it is preferable that the gas introduction hole 15 is connected to the groove 14a (boundary groove). Furthermore, it is more preferable that the gas introduction hole 15 is connected to each of the two grooves 14a provided across the boundary. In addition, in the example shown in FIG.9(b), two gas introduction holes 15 are provided in the area|region 100a. For example, both of the two gas introduction holes 15 may communicate with one gas supply channel 53 (see FIG. 1 ).

And, in the case where each of the two grooves 14a provided across the boundary is connected to the gas introduction hole 15, the center of the gas introduction hole 15 connected to one groove 14a is connected to the gas introduction hole connected to the other groove 14a. The angle formed by the line of the center of the hole 15 and the boundary may be less than 90°. In this case, the angle can be, for example, not less than 1.0° and not more than 89°, preferably not less than 2.0° and not more than 70°, more preferably not less than 3.0° and not more than 60°.

In this way, the boundary grooves can be brought closer to each other, and the area where the pressure of the gas changes can be reduced. Therefore, the region where the pressure of the intended gas can be increased can be increased.

Connect the gas introduction hole 15 connected to one groove 14a The angle formed by the center, the center of the gas introduction hole 15 connected to the other groove 14a, and the boundary may be 90°.

In this case, the angle is not limited to 90° in the strict sense, and for example, a difference in the degree of manufacturing error is allowed.

In this way, if the two gas introduction holes 15 are arranged at opposing positions, the gases supplied from the two gas introduction holes 15 with different pressures will antagonize each other. Therefore, it is easier to maintain the pressure in each zone at the target pressure.

FIG. 11 is a schematic plan view of a ceramic dielectric substrate 11 according to another embodiment. FIG. 11 is a schematic plan view of the ceramic dielectric substrate 11 shown in FIG. 2 .

As shown in FIG. 11 , a plurality of grooves 14 c may be further provided on the first main surface 11 a of the ceramic dielectric substrate 11 . The width of the groove 14c (dimension in the direction substantially perpendicular to the extending direction of the groove) can be, for example, 0.1 mm or more and 1 mm or less. The depth (dimension in the Z direction) of the groove 14 c can be, for example, not less than 50 μm and not more than 150 μm.

In this example, at least one groove 14 c is provided in each of the regions 101 , 102 , and 104 . The groove 14c connects the plurality of grooves 14a and 14b provided in one region. Therefore, the gas supplied to the groove 14a connected to the gas introduction hole 15 flows along the groove 14a, passes through the groove 14c, and is supplied to the groove 14b or another groove 14a. Since the gas flow can be smoothed by providing the groove 14c, even in the case where there is no seal ring, it is possible to suppress the generation of pressure distribution in the area. Furthermore, even if the top of the dot 13 is worn away to narrow the gap between the object W and the first main surface 11a, the gas can be supplied to the groove 14b or another groove 14a through the groove 14c.

The groove 14c is arranged so that the groove 14a and the groove 14b communicate with each other. The groove 14c may extend, for example, in a direction intersecting the grooves 14a and 14b.

For example, as shown in FIG. 11 , a plurality of grooves 14 c may be provided on a line passing through the center of the ceramic dielectric substrate 11 . In addition, the plurality of grooves 14c does not necessarily need to be provided on a line passing through the center of the ceramic dielectric substrate 11 . And, although the linear groove 14c has been described as an example, the groove 14c can be a curved groove 14c or a groove having a linear portion and a curved portion in the range where the groove 14c can communicate with the groove 14a and the groove 14b. 14c. The number, arrangement, shape, etc. of the plurality of grooves 14c can be appropriately changed according to the size of the object W, the required specification of the temperature distribution on the object W, and the like. The number, arrangement, shape, etc. of the plurality of grooves 14c can be appropriately determined by conducting experiments or simulations, for example.

In the aspect of the present invention in which no seal ring is provided, efforts are made to improve the responsiveness of the gas pressure in the region. As an example, the gas pressure in the region can be effectively controlled by providing the groove 14c that communicates the groove 14a and the groove 14b.

Moreover, since there is a gap at the height of the point 13 between the first main surface 11a and the object W, the gas supplied to the groove 14a connected to the gas introduction hole 15 passes through the gap and is supplied to the groove 14b or other grooves. 14a. However, if the top of the point 13 is worn away to narrow the gap between the object W and the first main surface 11a, the flow of gas in each region may be hindered, and pressure distribution may occur. If the groove 14c is provided, the gas can be supplied to the groove 14b or another groove 14a through the groove 14c even if the gap between the object W and the first main surface 11a is narrowed due to abrasion of the top of the dot 13 . Therefore, the time until the pressure in the region reaches a predetermined pressure can be greatly shortened, or Suppression creates pressure distribution in the area.

Moreover, as shown in FIG. 11 , it can be set in the area 101 (first area), and is closest to the boundary 102a (first boundary) between the area 101 and the area 102 (second area), and the area extending along the boundary 102a The groove 14a (first boundary groove) is provided with at least two gas introduction holes 15 (first gas introduction holes) capable of supplying gas.

In recent years, the density of semiconductor integrated circuits has been further advanced, and the density of plasma has also been increased in order to achieve further microfabrication. If the diameter of the gas introduction holes 15 is reduced in order to suppress arcing in the high-density plasma, individual differences may occur among the gas introduction holes 15 due to manufacturing unevenness. According to the aspect of this embodiment, the influence of the variation in the diameter of each gas introduction hole 15 can be suppressed, and a predetermined flow rate of gas can be more reliably supplied to the groove 14a extending along the boundary 102a.

And, as shown in FIG. 11 , at least two gas introduction holes 15 (second boundary grooves) that can supply gas can be provided in the region 102, and are arranged closest to the boundary 102a. gas inlet hole). In addition, in the example shown in FIG. 11, three gas introduction holes 15 are provided.

In this way, as described above, the influence of the variation in the diameter of each gas introduction hole 15 can be suppressed, and the gas can be more reliably supplied to the groove 14a extending along the boundary 102a.

Next, the effect of the groove 14c will be further described.

FIG. 12( a ) is a schematic plan view for illustrating the arrangement of grooves 14 related to a comparative example.

In FIG. 12( a ), a plurality of grooves 14 are provided on the surface of the substrate 110 . The plurality of grooves 14 are annular and concentrically arranged at equal intervals around the center 110 a of the substrate 110 . In addition, in FIG. 12(a), the groove 14c is not provided.

Fig. 12(b) is a schematic top view illustrating the arrangement of the groove 14 and the groove 14c.

In FIG. 12( b ), a plurality of grooves 14 and a plurality of grooves 14 c that communicate at least a part of the plurality of grooves 14 are provided. In this example, the groove 14c is provided on a line passing through the center 110a of the substrate 110 . The plurality of grooves 14 are connected to each other through the groove 14c.

FIG. 13 is a graph for illustrating the pressure change on the center 110 a of the substrate 110 . FIG. 13 is a graph showing the pressure change on the center 110a of the substrate 110 obtained by simulation. In the simulation, the object W supported by the point 13 is formed above the substrate 110 .

E in FIG. 13 is the case where a plurality of grooves 14 are provided as illustrated in FIG. 12( a ).

F in FIG. 13 is the case where a plurality of grooves 14 and a plurality of grooves 14 c are provided as illustrated in FIG. 12( b ).

It can be seen from Fig. 13 that in the case (case E) illustrated in Fig. 12(a), the pressure can only be increased to 95% of the specified pressure (20 Torr). This means that a pressure distribution can be generated in the area.

In the case (case F) illustrated in FIG. 12( b ), the pressure can be increased to a predetermined pressure (20 Torr). This means that pressure distribution in the area can be suppressed.

Furthermore, in the case of F, the time T1 required to increase to a predetermined pressure is shorter than the time T2 required to increase to a pressure of 95% of the specified pressure in the case of E. This means that the time until the pressure in the region reaches a predetermined pressure can be significantly shortened, in other words, the responsiveness of gas control and thus temperature control can be improved.

As mentioned above, it is preferable that the gas introduction hole 15 is connected to at least one of the two grooves 14a provided across the boundaries 101a to 103a.

For example, as illustrated in FIG. 11 , in the inner regions 101 , 102 , and 104 of the first main surface 11 a , the gas introduction holes 15 may be connected to the outermost grooves 14 a in each region. In the outermost region 103 of the first main surface 11a, the gas introduction hole 15 can be connected to the innermost groove 14a.

The number and arrangement of the gas introduction holes 15 provided in each area can be appropriately changed according to the size of the object W, the required specification of the temperature distribution on the object W, and the like. For example, as illustrated in FIG. 11 , three gas introduction holes 15 may be provided at equal intervals in one region. In this case, at least one of the plurality of gas introduction holes 15 provided in the region 103 and the gas introduction hole 15 provided in the region 102 may be arranged on a line passing through the center of the first main surface 11a.

The above is the case of the area where the pressure change of the gas is reduced in the vicinity of the boundary. However, if the gas is supplied to the grooves 14a and 14c provided in the area, the gas introduction hole 15 is provided at the position where the groove 14a and the groove 14c intersect or where the gas is supplied. Nearby is better. For example, when projected onto a plane perpendicular to the Z direction, on the part connecting the groove 14a and the groove 14c, at least A part overlaps with at least one of the groove 14a and the groove 14c. In this way, the gas supplied to the groove 14a can easily flow out to the side of the groove 14c. Therefore, it becomes easy to obtain the aforementioned effect of the groove 14c.

14(a)~(c) are schematic diagrams for illustrating the form of the groove 14c.

Fig. 14(b) is an enlarged view of part E in Fig. 14(a).

Fig. 14(c) is an enlarged view of part F in Fig. 14(a).

As shown in FIG. 14( b ), for example, the groove 14 c may be provided so as to overlap a line drawn from the center of the ceramic dielectric substrate 11 toward the outer periphery. In this case, at the portion connecting the groove 14a and the groove 14c, the angle formed by the tangent line of the groove 14a and the groove 14c can be 90°.

Furthermore, as shown in FIG. 14( c ), for example, the groove 14 c may not overlap a line drawn from the center toward the outer periphery of the ceramic dielectric substrate 11 . In this case, at the portion connecting the groove 14a and the groove 14c, the angle formed by the tangent of the groove 14a and the groove 14c is not 90°.

FIG. 15 is a schematic plan view of a ceramic dielectric substrate 11 according to another embodiment.

In the case illustrated in FIGS. 9 and 11 , the first main surface 11 a is concentrically divided into a plurality of regions 101 to 104 . In contrast, in the case illustrated in FIG. 15 , the first main surface 11 a is divided into a plurality of regions 105 that are closely attached to each other. A plurality of regions 105 may be arranged side by side. Although there is no particular limitation on the shape of the plurality of regions 105, a shape that can adhere to each other is preferred. The plurality of regions 105 can be in a polygonal shape such as a triangle or a quadrangle, for example. The outline of the region 105 illustrated in Figure 15 The shape is a regular hexagon. The external shape, number, arrangement, etc. of the plurality of regions 105 can be appropriately changed according to the size of the object W, the required specification of the temperature distribution on the object W, and the like. The shape, quantity, arrangement, etc. of the plurality of regions 105 can be appropriately determined by conducting experiments or simulations, for example.

The groove 14a is provided along the boundary 105a of the region 105 . The groove 14a is provided on both sides with the boundary 105a interposed therebetween. At least one groove 14 b is provided in the region 105 . The groove 14b may be arranged concentrically with the groove 14a. The number and position of the grooves 14b provided in one region can be appropriately changed according to the size of the object W, the required specification of the temperature distribution on the object W, and the like. The number, positions, and the like of the grooves 14b provided in one region can be appropriately determined by conducting experiments or simulations, for example.

Others are the same as above, groove 14c, gas inlet hole 15, point 13, ejector pin hole 16, outer seal 17, etc. can be provided.

(processing device)

FIG. 16 is a schematic diagram illustrating an example of a processing device 200 related to the embodiment.

As shown in FIG. 16 , an electrostatic chuck 1 , a power source 210 , a medium supply unit 220 , and a supply unit 230 can be arranged in the processing apparatus 200 .

The power source 210 is electrically connected to the electrode 12 disposed on the electrostatic chuck 1 . The power supply 210 can be, for example, a DC power supply. The power supply 210 applies a predetermined voltage to the electrodes 12 . Furthermore, a switch for switching between application of a voltage and stop of application of a voltage may be disposed on the power supply 210 .

The medium supply part 220 is connected to the input channel 51 and the output channel 52 . The medium supply part 220, for example, can be regarded as a cooling medium or heat preservation Medium liquid supply.

The medium supply unit 220 has, for example, a storage unit 221 , a control valve (control valve) 222 , and a discharge unit 223 .

The storage unit 221 can be used as a tank for storing liquid, factory piping, or the like, for example. In addition, a cooling device and/or a heating device for controlling the temperature of the liquid may be disposed in the storage portion 221 . The accommodating part 221 may be provided with a pump or the like for sending out the liquid.

The control valve 222 is connected between the input channel 51 and the storage part 221 . The control valve 222 can control at least one of the flow rate and the pressure of the liquid. Also, the control valve 222 can switch the supply and stop of the liquid.

The discharge part 223 is connected to the output channel 52 . The discharge portion 223 can be used as a tank, a drain pipe, or the like that recovers the liquid discharged from the output channel 52 . In addition, the discharge part 223 is not necessarily required, and the liquid discharged from the output channel 52 may be supplied to the storage part 221 . In this way, since the cooling medium or the heat insulating medium can be circulated, resource saving can be achieved.

The supply unit 230 has a gas supply unit 231 and a gas control unit 232 .

The gas supply unit 231 can be used as a high-pressure cylinder or factory piping that stores gas such as helium. In addition, although the case where one gas supply part 231 was provided was exemplified, a plurality of gas supply parts 231 may be provided.

The gas control unit 232 is connected between the plurality of gas supply channels 53 and the gas supply unit 231 . The gas control unit 232 can control at least one of the flow rate and the pressure of the gas. Furthermore, the gas control unit 232 may further have a function of switching the supply and stop of the gas. Gas Control Section 232 For example, a mass flow controller or a mass flow meter can be used.

As shown in FIG. 16 , a plurality of gas control units 232 may be provided. For example, the gas control unit 232 may be provided for every plurality of areas 101-104. In this way, the gas supplied can be controlled for each of the plurality of regions 101 to 104 . In this case, the gas control unit 232 can also be provided for every plurality of gas supply channels 53 . In this way, the gas in the plurality of regions 101 to 104 can be controlled more precisely. Moreover, although the case where the several gas control part 232 was provided was demonstrated as an example, if the gas control part 232 can independently control the supply of the gas in several supply systems, it may be one.

Here, the means for holding the object W includes a vacuum chuck, a mechanical chuck, or the like. However, the vacuum pad cannot be used in an environment reduced to a pressure lower than atmospheric pressure. Furthermore, if a mechanical chuck is used, the object W may be damaged or particles may be generated. Therefore, for example, an electrostatic chuck is used in a processing device used in a semiconductor manufacturing process or the like.

In such a processing device, the processing space needs to be isolated from the external environment. Therefore, the processing device 200 may further include a reaction chamber (chamber) 240 . The reaction chamber 240 can be, for example, an airtight structure having an environment capable of maintaining a pressure reduced to a pressure lower than atmospheric pressure.

Furthermore, the processing device 200 may include a plurality of ejector pins, and a driving device for raising and lowering the plurality of ejector pins. When receiving the object W from the conveying device or delivering the object W to the conveying device, the ejector pin is raised by the driving device and protrudes from the first main surface 11 a. In the pair that will receive from the carrier When the object W is placed on the first main surface 11a, the ejector pins are lowered by the driving device to be accommodated in the interior of the ceramic dielectric substrate 11.

Furthermore, various devices can be arranged in the processing device 200 according to the content of processing. For example, a vacuum pump or the like for exhausting the inside of the reaction chamber 240 may be provided. A plasma generating device that generates plasma inside the reaction chamber 240 may be disposed. A process gas supply unit that supplies process gas to the inside of the reaction chamber 240 may be disposed. A heater for heating the object W or the process gas may be disposed inside the reaction chamber 240 . In addition, the devices disposed in the processing device 200 are not limited to the illustrated devices. Since known techniques can be applied to devices disposed in the processing device 200 , detailed descriptions are omitted.

As described above, the processing apparatus 200 related to the form of the present embodiment includes the above-mentioned electrostatic chuck 1 and can independently control the gas supply to the first gas introduction hole (gas introduction hole 15 ) and the second gas introduction hole provided on the electrostatic chuck 1 . The gas control part (gas control part 232) of the gas of the gas introduction hole (gas introduction hole 15). According to the processing apparatus 200 according to the aspect of this embodiment, the pressure of the gas in each area can be made into an appropriate pressure.

The embodiments of the present invention have been described above. However, the present invention is not limited to these descriptions. For example, although the configuration using Coulomb force was exemplified as the electrostatic chuck 1 , a configuration using Johnsen-Rahbeck force (Johnsen-Rahbeck force) may also be used. Furthermore, those skilled in the art may appropriately add that design changes are included in the scope of the present invention as long as they have the characteristics of the present invention regarding the above-mentioned embodiment. Moreover, each element included in each of the above-mentioned embodiments is as technically possible as possible. Combinations are possible, and combinations of these elements are included in the scope of the present invention as long as they also include the features of the present invention.

11: Ceramic dielectric substrate

11a: first major surface

11b: Second major surface

12: Electrode

13: Dots

14a, 14b: ditch

15: Gas inlet hole

17: Outer seal

20: Connecting part

90: the first porous part

101~104: area

L1~L4: distance between groove ends

P3: the pressure of the gas

W: object

Claims (27)

An electrostatic chuck, characterized by comprising: a bottom plate; and a ceramic dielectric substrate disposed on the bottom plate and having a first main surface exposed to the outside, the first main surface at least includes: a first region; adjacent to the In the second area of the first area, the first area of the first main surface is provided with: a plurality of first grooves; at least one first gas introduction hole connected to at least one of the plurality of first grooves, the plurality of A first ditch includes: a first boundary ditch disposed closest to the first boundary between the first region and the second region, and extending along the first boundary; at least one first region inner ditch, connected to the second region Different from a boundary groove, the second region of the first main surface is provided with: a plurality of second grooves; at least one second gas introduction hole connected to at least one of the plurality of second grooves, and the plurality of second The ditch includes: a second boundary ditch positioned closest to the first boundary and extending along the first boundary; The distance between the groove ends between the two boundary grooves is smaller than the distance between the groove ends between the first boundary groove and the grooves in the first region adjacent to the first boundary groove, the first boundary groove and the second boundary groove between ditch The distance between the ends of the grooves is smaller than the distance between the ends of the grooves between the second boundary groove and the grooves in the second region adjacent to the second boundary groove. The electrostatic chuck according to claim 1, wherein the distance between the ends of the first boundary groove and the second boundary groove is smaller than the distance between the ends of the grooves in the first region. The electrostatic chuck according to claim 1 or claim 2, wherein when projected onto a plane perpendicular to the first direction from the bottom plate to the ceramic dielectric substrate, at least a part of the first gas introduction hole is in contact with the first boundary Groove overlap. The electrostatic chuck according to claim 1 or claim 2, wherein when projected onto a plane perpendicular to the first direction from the bottom plate to the ceramic dielectric substrate, at least a part of the second gas introduction hole is in contact with the second boundary Groove overlap. The electrostatic chuck according to claim 1 or claim 2, wherein the angle formed between the center of the first gas introduction hole and the center of the second gas introduction hole and the first boundary is less than 90°. The electrostatic chuck according to claim 1 or claim 2, wherein the angle formed by the line connecting the center of the first gas introduction hole and the center of the second gas introduction hole and the first boundary is 90°. The electrostatic chuck according to claim 1 or claim 2, which further has a ejector pin hole arranged on the first main surface, and the distance between the ejector pin hole and the first boundary groove is shorter than the distance between the ejector pin hole and the first boundary groove. The distance between the grooves in the first region closest to the ejector pin hole is also greater. Such as the electrostatic chuck of claim 1 or claim 2, its The first main surface at least includes: the first region; the second region located outside the first region; a third region located outside the second region and adjacent to the second region, the plurality of second regions The groove includes a second boundary groove disposed closest to the second boundary between the second region and the third region, a second outer boundary groove extending along the second boundary, and a second boundary groove disposed adjacent to the second boundary in the third region. , a third boundary ditch extending along the second boundary, the distance between the ends of the second outer boundary ditch and the third boundary ditch is greater than the distance between the ends of the first boundary ditch and the second boundary ditch The distance is still large. The electrostatic chuck according to claim 8, wherein it is further equipped to surround the periphery of the first main surface, at least a part of which is sealed outside of contact with the object to be adsorbed, and is perpendicular to the direction from the bottom plate to the ceramic dielectric. In a second direction of the first direction of the substrate, the distance between the second boundary and the outer seal is smaller than the distance between the first boundary and the second boundary. The electrostatic chuck according to claim 4, wherein the first gas introduction hole can supply gas to the first boundary groove, and at least two first gas introduction holes are provided. The electrostatic chuck according to claim 10, wherein the second gas introduction hole can be provided to supply gas to the second boundary groove, and at least two second gas introduction holes are provided. An electrostatic chuck, characterized by comprising: a bottom plate; and a ceramic dielectric substrate disposed on the bottom plate and having a first main surface exposed to the outside, the first main surface at least includes: a first region; adjacent to the In the second region connected to the first region, the first region of the first main surface is provided with: a plurality of first grooves; at least one first gas introduction hole connected to at least one of the plurality of first grooves, The plurality of first grooves include: a first boundary groove, disposed closest to the first boundary between the first region and the second region, and extending along the first boundary; at least one groove in the first region, and The first boundary groove is different, and the second region of the first main surface is provided with: a plurality of second grooves; at least one second gas introduction hole connected to at least one of the plurality of second grooves, the plurality of The second ditch includes: a second boundary ditch arranged closest to the first boundary and extending along the first boundary; and at least one ditch in the second region, which is different from the second boundary ditch and has a prescribed unit area, The occupancy rate of the boundary ditch in the first range including the first boundary, the first boundary ditch, and the second boundary ditch is higher than that of the ditch in the first area, which has the same shape and the same size as that of the first range. The occupancy rate of the grooves in the area in the second range is still larger, and the distance between the groove ends between the first boundary groove and the second boundary groove is larger than that between the second boundary groove and the adjacent The distance between the groove ends of the grooves in this second region of the second boundary groove is also small. The electrostatic chuck according to claim 12, wherein the distance between the ends of the first boundary groove and the second boundary groove is smaller than the distance between the ends of the grooves in the first region. The electrostatic chuck according to claim 12 or claim 13, wherein when projected onto a plane perpendicular to the first direction from the bottom plate to the ceramic dielectric substrate, at least a part of the first gas introduction hole is in contact with the first boundary Groove overlap. The electrostatic chuck according to claim 12 or claim 13, wherein when projected onto a plane perpendicular to the first direction from the bottom plate to the ceramic dielectric substrate, at least a part of the second gas introduction hole is in contact with the second boundary Groove overlap. The electrostatic chuck according to claim 12 or claim 13, wherein the angle formed by the line connecting the center of the first gas inlet hole and the center of the second gas inlet hole and the first boundary is less than 90°. The electrostatic chuck according to claim 12 or claim 13, wherein the angle formed by the line connecting the center of the first gas inlet hole and the center of the second gas inlet hole and the first boundary is 90°. The electrostatic chuck according to claim 12 or claim 13, which further has a ejection pin hole arranged on the first main surface, and the distance between the ejection pin hole and the first boundary groove is shorter than the distance between the ejection pin hole and the first boundary groove. The distance between the grooves in the first region closest to the ejector pin hole is also greater. The electrostatic chuck according to claim 12 or claim 13, wherein the first main surface at least includes: the first region; located in the first region The second area outside the domain; the third area located outside the second area and adjacent to the second area, the plurality of second grooves include the second groove closest to the second area and the third area The second outer boundary ditch extending along the second boundary, the third boundary ditch arranged adjacent to the second boundary and extending along the second boundary in the third area has the specified In unit area, the boundary groove occupancy rate in the third range including the second boundary, the second outer boundary groove, and the third boundary groove is larger than the inner groove occupancy rate in the first range. The electrostatic chuck according to claim 19, wherein it is further equipped to surround the periphery of the first main surface, at least a part of which is sealed except for being in contact with the object to be adsorbed, and is perpendicular to the direction from the bottom plate to the ceramic dielectric In a second direction of the first direction of the substrate, the distance between the second boundary and the outer seal is smaller than the distance between the first boundary and the second boundary. An electrostatic chuck, characterized by comprising: a bottom plate; and a ceramic dielectric substrate disposed on the bottom plate and having a first main surface exposed to the outside, the first main surface at least includes: a first region; adjacent to the In the second area of the first area, the first area of the first main surface is provided with: a plurality of first groove; at least one first gas introduction hole connected to at least one of the plurality of first grooves, the plurality of first grooves are arranged closest to the first boundary between the first region and the second region, along The first boundary groove extending along the first boundary, the second region of the first main surface is provided with: a plurality of second grooves; at least one second gas introduction connected to at least one of the plurality of second grooves In the hole, the plurality of second grooves include: a second boundary groove disposed closest to the first boundary and extending along the first boundary; and at least one groove in a second region, different from the second boundary groove, the The distance between the groove ends between the first boundary groove and the second boundary groove exceeds 0 mm and is 60 mm or less, and the distance between the groove ends between the first boundary groove and the second boundary groove is larger than that between the second boundary groove and the adjacent The distance between the groove ends of the grooves in the second region of the second boundary groove is also small. The electrostatic chuck according to claim 21, wherein the distance between the ends of the first boundary groove and the second boundary groove exceeds 0 mm and is 20 mm or less. The electrostatic chuck according to claim 21 or claim 22, wherein when projected onto a plane perpendicular to the first direction from the bottom plate to the ceramic dielectric substrate, at least a part of the first gas introduction hole is in contact with the first boundary Groove overlap. The electrostatic chuck as claimed in claim 21 or claim 22, wherein when projected onto the first direction perpendicular to the ceramic dielectric substrate from the base plate On a plane in one direction, at least a part of the second gas introduction hole overlaps with the second boundary groove. In the electrostatic chuck according to claim 21 or 22 of the patent claims, the angle between the line connecting the center of the first gas inlet hole and the center of the second gas inlet hole and the first boundary is less than 90°. The electrostatic chuck according to claim 21 or claim 22, wherein the angle formed by the line connecting the center of the first gas introduction hole and the center of the second gas introduction hole and the first boundary is 90°. The electrostatic chuck according to claim 21 or claim 22, wherein the plurality of first grooves further include: at least one inner groove in the first region different from the first boundary groove; ejection pin holes provided on the first main surface , the distance between the ejector pin hole and the first boundary groove is greater than the distance between the ejector pin hole and the groove in the first region closest to the ejector pin hole.

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