Holding member and electrostatic chuck

Abstract

A holding member is provided which suppresses arc discharge while simultaneously shortening the length of a flow path and saving space for the flow path. [Solution] A holding member for holding an object, comprising: a plate-shaped member having a holding surface for holding the object; and a gas flow path section formed within the plate-shaped member and capable of circulating gas from the side opposite the holding surface toward the holding surface side, the gas flow path section having a first flow path section extending perpendicular to the holding surface, and a second flow path section extending perpendicularly and communicating with the first flow path section, characterized in that, of the first transverse cross section which is a cross section of an end of the first flow path section, and the second transverse cross section which is a cross section of an end of the second flow path section, adjacent first transverse cross sections and second transverse cross sections overlap without one containing the other when viewed transparently from the perpendicular direction.

Description

[Technical field]

[0001] The present invention relates to a holding member and an electrostatic chuck. [Background technology]

[0002] As a holding member for holding an object, an electrostatic chuck that holds a wafer as an object by electrostatic attraction is known. For example, Patent Document 1 discloses an electrostatic chuck that includes a plurality of ceramic layers that are wafer ceramics to be placed under the wafer, and in which a flow path having a plurality of bends is formed by notches included in each ceramic layer. The flow path thus formed suppresses the acceleration of electrons included in the gas flowing through the flow path, and suppresses the occurrence of arc discharge. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6948767 Summary of the Invention [Problem to be solved by the invention]

[0004] In the flow path disclosed in Patent Document 1, since the flow path has multiple bends, the length of the flow path that the gas passes through before reaching the wafer side tends to be long, leading to a decrease in gas supply efficiency. In addition, in the flow path disclosed in Patent Document 1, the space required to arrange the flow path part in the wafer ceramic tends to be large, leading to restrictions on the arrangement of other components in the wafer ceramic. For this reason, there has been a demand for the development of a holding member that suppresses arc discharge while shortening the flow path length and saving space for the flow path.

[0005] The present invention has been made to solve at least some of the above-mentioned problems, and aims to provide a retaining member that suppresses arc discharge while shortening the flow path length and saving space in the flow path. [Means for solving the problem]

[0006] The present invention has been made to solve at least part of the above-mentioned problems, and can be realized in the following forms.

[0007] (1) According to one aspect of the present invention, there is provided a holding member for holding an object, the holding member comprising: a plate-shaped member having a holding surface for holding the object; and a gas flow path portion formed in the plate-shaped member and capable of circulating gas from an opposite side to the holding surface side toward the holding surface side, the gas flow path portion having a first flow path portion extending in a direction perpendicular to the holding surface and a second flow path portion extending in the perpendicular direction and communicating with the first flow path portion, wherein, among a first transverse cross section which is a transverse cross section of an end portion of the first flow path portion and a second transverse cross section which is a transverse cross section of an end portion of the second flow path portion, adjacent first transverse cross sections and second transverse cross sections overlap with each other without including one inside the other when viewed in the perpendicular direction.

[0008] According to this configuration, the adjacent first and second transverse sections overlap each other without one of them being enclosed within the other when viewed through in the vertical direction. That is, a surface facing the vertical direction is arranged around the portion where the adjacent first and second transverse sections overlap. Therefore, electrons contained in the gas flowing through the gas flow passage are likely to hit that surface, and the acceleration of the electrons that hit that surface is suppressed, so that the occurrence of arc discharge can be suppressed. In addition, according to this configuration, since both the first and second flow passage sections extend in the vertical direction, the flow passage length through which the gas passes before reaching the holding surface can be shortened compared to a gas flow passage section having multiple bends or a porous gas flow passage section. In addition, since both the first and second flow passage sections extend in the vertical direction, the space required for arranging the gas flow passage section in the plate-shaped member can be reduced. Therefore, according to this configuration, it is possible to provide a holding member that achieves both shortening the flow passage length of the gas flow passage section and saving space for the gas flow passage section while suppressing arc discharge.

[0009] (2) In the retaining member of the above aspect, a plurality of gas flow path sections may be formed within the plate-shaped member, and at least some of the gas flow path sections may have portions that overlap with other of the gas flow path sections when viewed transparently from the vertical direction. According to this configuration, since a plurality of gas flow passages are formed in the plate-like member, gas can be efficiently supplied to the holding surface side. Also, according to this configuration, since the plurality of gas flow passages can be arranged close to each other, it is possible to save space for the plurality of gas flow passages in the plate-like member.

[0010] (3) In the holding member of the above aspect, a plurality of gas flow passages may be formed within the plate-like member, and at least some of the gas flow passages may communicate with other gas flow passages. According to this configuration, since a plurality of gas flow passages are formed in the plate-like member, gas can be efficiently supplied to the holding surface side. Also, according to this configuration, even if the flow of gas is hindered in one gas flow passage due to clogging with particles or the like, gas can be circulated to other gas flow passages that are connected to the gas flow passage, so that a decrease in gas supply efficiency can be suppressed.

[0011] (4) In the holding member of the above aspect, a conductive member may be provided near the gas flow path portion and extending along the vertical direction. According to this configuration, since the conductive member extending in the vertical direction is provided near the gas flow path, when high frequency power is applied from the side opposite to the holding surface of the plate member, it is possible to suppress the generation of a potential difference between the holding surface side of the gas flow path and the opposite side, thereby further suppressing the generation of arc discharge.

[0012] (5) In the holding member of the above aspect, a volume of the first flow path portion or the second flow path portion that opens to the opposite side of the gas flow path portion may be larger than a volume of the first flow path portion or the second flow path portion that opens to the holding surface side of the gas flow path portion. According to this configuration, the volume of the first flow path section or the second flow path section that opens to the side opposite to the holding surface side of the gas flow path section is relatively large, so that the amount of gas flowing into the gas flow path section can be secured. Also, the volume of the first flow path section or the second flow path section that opens to the holding surface side of the gas flow path section is relatively small, so that electrons contained in the gas flowing through the gas flow path section are unlikely to accelerate, so that gas can be supplied to the holding surface side while suppressing the occurrence of arc discharge.

[0013] (6) According to another aspect of the present invention, there is provided an electrostatic chuck comprising the holding member according to any one of (1) to (5) above, and an electrostatic electrode that generates an electrostatic attractive force on the holding surface. According to this configuration, an electrostatic attraction (adsorption force) is generated by supplying power to the electrostatic electrode, and the target object can be held on the holding surface side by this electrostatic attraction. In addition, since the gas flow passage portion has the first flow passage portion and the second flow passage portion, it is possible to provide an electrostatic chuck that realizes all of the following: suppression of the occurrence of arc discharge, improvement of the efficiency of supplying gas to the holding surface side, and space saving of the gas flow passage portion.

[0014] The present invention can be realized in various forms, for example, in the form of a holding member, an electrostatic chuck equipped with an electrostatic electrode that generates electrostatic attraction on the holding member and the holding surface of the holding member, a vacuum chuck, a ceramic heater, semiconductor manufacturing equipment, parts equipped with these, and methods of manufacturing these, etc. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is an explanatory diagram illustrating a cross-sectional configuration of an electrostatic chuck according to a first embodiment. [Diagram 2] FIG. 4 is an explanatory diagram of a gas flow passage portion. [Diagram 3] FIG. 4 is an explanatory view showing a flow path portion when viewed through a laminate; [Figure 4] 11 is an explanatory diagram showing a gas flow path portion in an electrostatic chuck according to a second embodiment. FIG. [Diagram 5] 13 is an explanatory diagram showing a gas flow path portion in an electrostatic chuck according to a third embodiment. FIG. [Figure 6] 13 is an explanatory diagram showing a gas flow path portion in an electrostatic chuck according to a fourth embodiment. FIG. [Figure 7] FIG. 13 is an explanatory view illustrating a cross-sectional configuration of an electrostatic chuck according to a fifth embodiment. [Figure 8] 13 is an explanatory diagram of a gas flow path portion in an electrostatic chuck according to a sixth embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] First Embodiment FIG. 1 is an explanatory diagram showing a schematic cross-sectional configuration of an electrostatic chuck 1 according to a first embodiment of the present invention. The electrostatic chuck 1 is a device that adsorbs and holds a semiconductor wafer W, which is an object, by electrostatic attraction. In FIG. 1, mutually orthogonal X, Y and Z axes are shown to specify a direction. In FIG. 1, the semiconductor wafer W held by the electrostatic chuck 1 is shown in the +Z axis direction from the electrostatic chuck 1. The electrostatic chuck 1 is used, for example, to fix the semiconductor wafer W in a vacuum chamber of a semiconductor manufacturing device. The electrostatic chuck 1 includes a plate-shaped member 10, a base member 20, an adhesive member 30, and an electrostatic electrode 40.

[0017] The plate-shaped member 10 is a disk-shaped member. The main component of the material forming the plate-shaped member 10 is ceramics. The main component refers to the component with the highest volume content. Examples of materials forming the plate-shaped member 10 include aluminum oxide (alumina, Al2O3) and aluminum nitride (AlN). The plate-shaped member 10 has a holding surface 10f that holds the semiconductor wafer W as an object. The holding surface 10f is a circular surface facing the side that holds the semiconductor wafer W (the side in the +Z axis direction).

[0018] The holding surface 10f is formed with an annular convex portion 12, a plurality of convex portions 14, and a plurality of concave portions 16. The annular convex portion 12 is formed along the outer edge of the holding surface 10f. Each of the convex portions 14 is formed inside the annular convex portion 12. Each of the concave portions 16 is formed between the convex portions 14. In other words, the concave portions 16 are formed at positions inside the annular convex portion 12 where no convex portion 14 is formed. When the holding surface 10f is viewed from a direction facing the holding surface 10f (when viewed from above), each of the concave portions 16 is arranged in a scattered manner on the circular holding surface 10f.

[0019] The base member 20 is a disk-shaped member bonded to the plate-shaped member 10 via an adhesive member 30, which will be described later. The material forming the base member 20 includes metals and various composite materials. Examples of the metal forming the base member 20 include Al (aluminum), Ti (titanium), and alloys thereof. Examples of the composite material forming the base member 20 include a composite material formed by melting an aluminum alloy mainly composed of aluminum into a porous ceramic mainly composed of silicon carbide (SiC) and pressurizing the melted aluminum alloy to infiltrate the porous ceramic mainly composed of silicon carbide (SiC). The aluminum alloy contained in the composite material may include Si (silicon) or Mg (magnesium), or may include other elements within a range that does not affect the properties, etc. In addition, a coolant flow path may be formed inside the base member 20 to flow a coolant for cooling the semiconductor wafer W through the base member 20 when the semiconductor wafer W is held by the electrostatic chuck 1.

[0020] When an upper electrode (not shown) is disposed on the +Z-axis direction side of the holding surface 10f, high frequency power can be applied between the upper electrode and the base member 20 to generate plasma for processing the surface of the semiconductor wafer W. An AC power source 25 is connected to the base member 20 as a supply source of high frequency power.

[0021] The adhesive member 30 is disposed between the plate-shaped member 10 and the base member 20, and bonds the plate-shaped member 10 and the base member 20. The adhesive member 30 is made of an adhesive material such as a silicone resin, an acrylic resin, or an epoxy resin. The adhesive member 30 may also contain a filler such as a ceramic such as Al2O3 or AlN. The adhesive member 30 may also be made of a metallic adhesive material such as aluminum or an aluminum alloy.

[0022] The electrostatic electrode 40 is a disk-shaped member provided inside the plate-shaped member 10, and is made of a conductive material such as tungsten or molybdenum. The electrostatic electrode 40 generates an electrostatic attractive force on the holding surface 10f by using power supplied from an external power source via a metal terminal 45 arranged inside the base member 20.

[0023] When electrostatic attraction is generated on the holding surface 10f, the semiconductor wafer W is held on the holding surface 10f by contacting with the annular convex portion 12 and the convex portion 14. In a state in which the semiconductor wafer W is held on the holding surface 10f, in order to increase the thermal conductivity between the semiconductor wafer W and the holding surface 10f, an inert gas such as helium gas is supplied between the semiconductor wafer W and the holding surface 10f. In detail, the inert gas is supplied from the opposite side (the -Z-axis side in FIG. 1) to the holding surface 10f side (the +Z-axis side in FIG. 1) through the through holes HL described later toward the holding surface 10f side. The inert gas supplied to the holding surface 10f side flows through the space between the semiconductor wafer W and the recess 16 and diffuses throughout the space.

[0024] A through hole HL is formed in the electrostatic chuck 1 as a flow path for flowing the inert gas toward the holding surface 10f. The through hole HL is composed of a first through hole H1, a second through hole H2, and a third through hole H3. The second through hole H2 is a through hole formed in the base member 20 along the Z-axis direction. The third through hole H3 is a through hole formed in the adhesive member 30 along the Z-axis direction and is connected to an end of the second through hole H2 on the +Z-axis direction side. The first through hole H1 is a through hole formed in the plate-shaped member 10 and is connected to an end of the third through hole H3 on the +Z-axis direction side. The first through hole H1 is composed of a portion V extending along the thickness direction (Z-axis direction) of the plate-shaped member 10, a portion P extending parallel to the holding surface 10f, and a gas flow path portion F described later. The gas flow passage F is a flow passage formed in the plate-like member 10, and is capable of circulating an inert gas from the opposite side (the -Z-axis side in FIG. 1) of the holding surface 10f side (the +Z-axis side in FIG. 1) toward the holding surface 10f side. The plate-like member 10 and the gas flow passage F of the electrostatic chuck 1 constitute a holding member H that holds a semiconductor wafer W as an object. The stacked body L will be described with reference to FIG. 2.

[0025] FIG. 2 is an explanatory diagram of the gas flow passage section F. FIG. 2(A) shows an enlarged view of the periphery of the gas flow passage section F in the plate-like member 10. FIG. 2(B) shows the state in which the green sheets G1 to G6 that define the gas flow passage section F are separated. FIG. 2(C) shows each of the green sheets G1 to G6 as viewed from the +Z-axis direction. Each of the green sheets G1 to G6 has a substantially identical disk shape and substantially the same thickness, and the flow passage sections F1 to F6 that penetrate the green sheets G1 to G6 are formed in each of the green sheets G1 to G6. Each of the flow passage sections F1 to F6 is a cylindrical through hole that extends in a direction perpendicular to the holding surface 10f (the Z-axis direction in FIG. 2), and each of the flow passage sections F1 to F6 has substantially the same volume. Note that the vertical direction here includes not only a completely vertical direction but also an approximately vertical direction that can be regarded as a vertical direction at a glance. Each of the central axes X1 to X6 is a central axis of each of the flow passage sections F1 to F6. The central axes X1 to X6 are all aligned along the vertical direction, but are located at different positions on a plane (XY plane in FIG. 2) perpendicular to the vertical direction. Specifically, the central axes X1 to X6 are located at the same position on the Y axis direction, but are located at different positions on the X axis direction. That is, the flow passage sections F1 to F6 are located at the same position on the Y axis direction, but are located at different positions on the X axis direction. The maximum length of each of the flow passage sections F1 to F6 along the Z axis direction (the length indicated by the double-headed arrow in the flow passage section F2 in FIG. 2(B)) is preferably 0.25 mm or less, more preferably 0.15 mm or less. In addition, the maximum length of two adjacent flow passage sections along the Z axis direction (the length indicated by the double-headed arrow in the flow passage section F in FIG. 2(A)) is preferably 0.50 mm or less, more preferably 0.30 mm or less. By designing the lengths as described above, the occurrence of arc discharge in the gas flow passage section F can be sufficiently suppressed.

[0026] As shown in Fig. 2, in this embodiment, the gas flow path section F is defined by stacking the disk-shaped green sheets G1-G6. In detail, the gas flow path section F is defined by the flow path sections F1-F6 being connected to each other when the disk-shaped green sheets G1-G6 are stacked. That is, the gas flow path section F has the flow path sections F1-F6. Then, the gas flow path section F is disposed in the plate-shaped member 10 by fitting a cylindrical laminate L (see Fig. 2(A)) in which the green sheets G1-G6 are stacked, into a space that connects the portion P of the plate-shaped member 10 and the holding surface 10f along the Z-axis direction (the space in which the laminate L is fitted in Fig. 1). In the manufacturing process of the plate-shaped member 10, the laminate L before firing may be fitted into the plate-shaped member 10 before firing, and then fired together with the plate-shaped member 10, or the laminate L before firing may be fitted into the fired plate-shaped member 10, and then fired together with the plate-shaped member 10. Also, the fired laminate L may be fitted into the fired plate-shaped member 10. When the laminate L is fired, the boundaries of the green sheets G1 to G6 disappear. The surface VP shown in FIG. 2(A) and the cross sections Sd1, Su2, Sd2, and Su3 shown in FIG. 2(B) will be described later.

[0027] Fig. 3 is an explanatory diagram showing the flow path sections F1 and F2 of the gas flow path section F when the laminate L is seen through in a vertical direction. In Fig. 3, in order to make it easier to see the overlap of the flow path sections F1 and F2, the laminate L seen through is not hatched as in Fig. 2. Fig. 3 shows the overlap of the flow path sections F1 and F2 when seen through in a vertical direction, and illustrates the outer edge Eg of the flow path section F2 that is visible inside the flow path section F1.

[0028] As shown in FIG. 2(A) and (B), the flow path section F1 and the flow path section F2 are adjacent to each other. Furthermore, as shown in FIG. 2(B), the cross section Sd1 of the end of the flow path section F1 on the -Z axis direction side and the cross section Su2 of the end of the flow path section F2 on the +Z axis direction side are adjacent to each other. The cross section here refers to a cross section of the flow path section cut by a plane perpendicular to the central axis of the target flow path section. As shown in FIG. 3, the adjacent cross sections Sd1 and Su2 overlap each other without including one inside the other when viewed in a vertical direction. Similar to the overlapping of the cross sections Sd1 and Su2, the adjacent cross sections in the flow path sections F1 to F6 overlap each other without including one inside the other.

[0029] In this way, each of the flow path sections F1 to F6 constituting the gas flow path section F corresponds to a first flow path section extending in a direction perpendicular to the holding surface 10f, and a second flow path section extending in a direction perpendicular to the holding surface 10f and communicating with the first flow path section. That is, the flow path sections F1 to F6 correspond to three first flow path sections and three second flow path sections. For example, when the flow path section F1 is regarded as the first flow path section, the flow path section F2 corresponds to the second flow path section, while when the flow path section F1 is regarded as the second flow path section, the flow path section F2 corresponds to the first flow path section. That is, each of the flow path sections F1 to F6 can be regarded as the first flow path section or the second flow path section, and the flow path sections F1 to F6 can be said to be three first flow path sections and three second flow path sections arranged alternately. In such a first flow path section and a second flow path section, among the first cross section which is a cross section of an end of the first flow path section and the second cross section which is a cross section of an end of the second flow path section, the adjacent first cross section and second cross section overlap each other without including one inside the other when viewed in a vertical direction. For example, when the flow path section F2 is regarded as the first flow path section and the flow path sections F1 and F3 are regarded as the second flow path sections (see FIG. 2(B)), the cross section Su2 (first cross section) of the end of the flow path section F2 on the +Z axis direction side and the cross section Sd1 (second cross section) of the end of the flow path section F1 on the -Z axis direction side, and the cross section Sd2 (first cross section) of the end of the flow path section F2 on the -Z axis direction side and the cross section Su3 (second cross section) of the end of the flow path section F3 on the +Z axis direction side overlap each other without including one inside the other when viewed in a vertical direction.

[0030] According to the electrostatic chuck 1 of the first embodiment described above, the adjacent cross sections of the cross sections of the end portions of the flow passage portions F1 to F6 overlap each other without including one inside the other when viewed through from the vertical direction. That is, a surface VP (see FIG. 2(A)) facing the vertical direction is arranged around the portion where the cross sections of the adjacent end portions overlap. Therefore, electrons contained in the inert gas flowing through the gas flow passage portion F are likely to hit the surface VP, and the acceleration of the electrons that hit the surface VP is suppressed, so that the occurrence of arc discharge can be suppressed. In addition, according to the electrostatic chuck 1 of the first embodiment, each of the flow passage portions F1 to F6 corresponding to the first and second flow passage portions extends in the vertical direction, so that the flow passage length through which the inert gas passes before reaching the holding surface 10f side can be shortened compared to a gas flow passage portion having a plurality of bends or a porous gas flow passage portion. Furthermore, since each of the flow path portions F1 to F6 corresponding to the first and second flow path portions extends in the vertical direction, it is possible to reduce the space required to arrange the gas flow path portion F within the plate-shaped member 10. Therefore, according to the electrostatic chuck 1 of the first embodiment, it is possible to provide an electrostatic chuck 1 including a holding member H that achieves both a shortened flow path length of the gas flow path portion F and a space-saving gas flow path portion F while suppressing arc discharge.

[0031] <Second embodiment> 4 is an explanatory diagram showing a gas flow path portion Fa in an electrostatic chuck 1a according to a second embodiment of the present invention. The electrostatic chuck 1a of the second embodiment is the same as the electrostatic chuck 1 of the first embodiment (see FIG. 1) except that the shape of the gas flow path portion Fa formed in a plate-shaped member 10 is different from the shape of the gas flow path portion F.

[0032] FIG. 4(A) shows the gas flow path section Fa seen through from a vertical direction, as in FIG. 3. FIG. 4(B) is a perspective view of the gas flow path section Fa. In order to make the shape of the gas flow path section Fa easier to see, the laminate (green sheet) around the gas flow path section Fa is not shown in FIGS. 4(A) and 4(B). The shape of the gas flow path section Fa in the second embodiment is spiral, as shown in FIG. 4(B). That is, each of the flow path sections Fa1 to Fa8 constituting the gas flow path section Fa is arranged in a spiral shape. Note that in FIG. 3, the outer edge Eg of the flow path section F2 seen from the inside of the flow path section F1 is shown, but in FIG. 4(A) to make the drawing easier to see, the outer edge of the other flow path section seen from the inside of one of the adjacent flow path sections is omitted. For example, the outer edge of the flow path section Fa1 seen from the inside of the flow path section Fa2 is omitted, and the outer edges of the flow path sections Fa2 to 7 seen from the inside of the flow path sections Fa3 to 8 are also omitted. Each of the flow path sections Fa1 to Fa8 corresponds to four first flow path sections and four second flow path sections, similar to each of the flow path sections F1 to F6 in the first embodiment, and adjacent cross sections among the cross sections at the end of each of the flow path sections Fa1 to Fa8 overlap with each other without including one inside the other when viewed in a vertical direction. In Fig. 4(B), cross sections Sa3 and Sa4 are shown as examples of two cross sections that overlap with each other without including one inside the other.

[0033] The electrostatic chuck 1a of the second embodiment described above can also achieve the same effects as the electrostatic chuck 1 of the first embodiment. Furthermore, in the electrostatic chuck 1a of the second embodiment, since the gas flow path portion Fa is spiral, it is possible to further reduce the space required for the gas flow path portion Fa.

[0034] <Third embodiment> 5 is an explanatory diagram showing gas flow passage portions Fb1-Fb5 of an electrostatic chuck 1b according to a third embodiment of the present invention. The electrostatic chuck 1b of the third embodiment is the same as the electrostatic chuck 1a of the second embodiment (see FIG. 4) except that a plurality of spiral gas flow passage portions Fb1-Fb5 are formed in a plate-shaped member 10.

[0035] FIG. 5 shows the gas flow passage sections Fb1 to Fb5 seen through in the vertical direction. In order to make the shape of each of the gas flow passage sections Fb1 to Fb5 easier to see, FIG. 5 does not show the laminate (green sheet) around the gas flow passage sections Fb1 to Fb5, as in FIG. 4. Each of the gas flow passage sections Fb1 to Fb5 of the third embodiment has a spiral shape, similar to the gas flow passage section Fa of the second embodiment (see FIG. 4). Each of the gas flow passage sections Fb1 to Fb5 formed in the plate-shaped member 10 has a portion that overlaps with the other gas flow passage sections Fb1 to Fb5 when seen through in the vertical direction (Z-axis direction). In FIG. 5, the portion that overlaps with the other gas flow passage sections Fb1 to Fb5 is hatched in a dot pattern. The gas flow passage section Fb1 communicates with the other gas flow passage section Fb2 via a connection flow passage CM.

[0036] The electrostatic chuck 1b of the third embodiment described above can also achieve the same effects as the electrostatic chuck 1 of the first embodiment. Furthermore, in the electrostatic chuck 1b of the third embodiment, since a plurality of gas flow passage portions Fb1 to Fb5 are formed in the plate-shaped member 10, gas can be efficiently supplied to the holding surface 10f side.

[0037] 5, each of the gas flow passage portions Fb1-Fb5 has a portion overlapping with the other gas flow passage portions Fb1-Fb5 when viewed in a vertical direction. Therefore, the gas flow passage portions Fb1-Fb5 can be disposed close to each other, thereby reducing the space required for the gas flow passage portions Fb1-Fb5 in the plate-shaped member 10.

[0038] In the electrostatic chuck 1b of the third embodiment, the gas flow passage portion Fb1 communicates with another gas flow passage portion Fb2 via a connection flow passage CM. Therefore, even if the flow of the inert gas is hindered in the gas flow passage portion Fb1 due to clogging with particles or the like, the inert gas can be caused to flow to the other gas flow passage portion Fb2 with which the gas flow passage portion Fb1 is connected, and therefore it is possible to suppress a decrease in the supply efficiency of the inert gas.

[0039] <Fourth embodiment> FIG. 6 is an explanatory diagram showing gas flow passage portions Fb1 to Fb5 and gas flow passage portions Fc1 to Fc5 in an electrostatic chuck 1c according to a fourth embodiment of the present invention. The electrostatic chuck 1c according to the fourth embodiment is the same as the electrostatic chuck 1b according to the third embodiment (see FIG. 5) except that the electrostatic chuck 1c does not include a connection flow passage CM and that a plurality of spiral gas flow passage portions Fc1 to Fc5 are formed in addition to the plurality of spiral gas flow passage portions Fb1 to Fb5 in the plate-shaped member 10. Each of the gas flow passage portions Fc1 to Fc5 is disposed between the gas flow passage portions Fb1 to Fb5. As shown in FIG. 6, each of the gas flow passage portions Fc1 to Fc5 has a portion overlapping with the gas flow passage portions Fb1 to Fb5 when seen through from the vertical direction (Z-axis direction).

[0040] The electrostatic chuck 1c of the fourth embodiment described above can also achieve the same effects as the electrostatic chuck 1 of the first embodiment. Furthermore, in the electrostatic chuck 1c of the fourth embodiment, since a plurality of gas flow passage portions Fb1-Fb5, Fc1-Fc5 are formed in the plate-shaped member 10, gas can be efficiently supplied to the holding surface 10f side.

[0041] <Fifth embodiment> 7 is an explanatory diagram illustrating a cross-sectional configuration of an electrostatic chuck 1d according to a fifth embodiment of the present invention. The electrostatic chuck 1d according to the fifth embodiment is the same as the electrostatic chuck 1 according to the first embodiment (see FIG. 1) except that a conductive member 18 is provided in the electrostatic chuck 1 according to the first embodiment.

[0042] The conductive member 18 is provided near the gas flow passage section F and extends along the vertical direction (Z-axis direction in FIG. 7). The term "near" here means within a certain range from the gas flow passage section F. For example, the conductive member 18 is disposed at a position closer to the gas flow passage section F than the electrostatic electrode 40 in a plane perpendicular to the vertical direction (XY plane in FIG. 7). In this embodiment, the conductive member 18 is a cylindrical member that covers the periphery of the gas flow passage section F, but may be, for example, a rod-shaped member as long as it is provided near the gas flow passage section F and extends along the vertical direction. In this embodiment, the end of the conductive member 18 on the +Z-axis direction side is not exposed to the holding surface 10f, but the end may be exposed to the holding surface 10f. In this embodiment, the end of the conductive member 18 on the -Z-axis direction side is connected to the base member 20. However, if the adhesive member 30 is a metallic adhesive and thus has conductivity, the end may be connected to the adhesive member 30 without being connected to the base member 20.

[0043] When high-frequency power is applied between an upper electrode (not shown) located on the +Z-axis direction side of the holding surface 10f and the base member 20 in order to generate plasma for processing the surface of the semiconductor wafer W, the conductive member 18 is connected to the base member 20 (or the conductive adhesive member 30), thereby suppressing the generation of a potential difference between the holding surface side and the opposite side of the gas flow path section F.

[0044] The electrostatic chuck 1d of the fifth embodiment described above can also achieve the same effects as the electrostatic chuck 1 of the first embodiment. Furthermore, in the electrostatic chuck 1d of the fifth embodiment, the conductive member 18 extending along the vertical direction is provided in the vicinity of the gas flow path portion F. Therefore, when high-frequency power is applied from the side opposite to the holding surface 10f side of the plate-shaped member 10, it is possible to suppress the generation of a potential difference between the holding surface 10f side of the gas flow path portion F and the opposite side. Therefore, it is possible to further suppress the generation of an arc discharge.

[0045] Sixth Embodiment 8 is an explanatory diagram of a gas flow passage portion Fe in an electrostatic chuck 1e according to a sixth embodiment of the present invention. The electrostatic chuck 1e of the sixth embodiment is the same as the electrostatic chuck 1 of the first embodiment (see FIG. 2) except that the volumes of the flow passage portions Fe1 to Fe6 (see FIG. 8(B)) constituting the gas flow passage portion Fe are different from one another.

[0046] FIG. 8(A) shows the laminate Le fitted in the plate-like member 10. FIG. 8(B) shows the state in which the green sheets Ge1 to Ge6 that define the gas flow path portion Fe are separated. The laminate Le is a cylindrical laminate in which the green sheets Ge1 to Ge6 are laminated. The flow path portions Fe1 to Fe6 are formed in each of the green sheets Ge1 to Ge6 that are substantially the same disk shape and substantially the same thickness. Each of the flow path portions Fe1 to Fe6 is a cylindrical through hole. The flow path portions Fe1 to Fe6 have different volumes. In detail, the flow path portions arranged closer to the -Z axis direction among the flow path portions Fe1 to Fe6 have larger volumes. That is, the flow path portion Fe1 has the smallest volume among the flow path portions Fe1 to Fe6, and the flow path portion Fe6 has the largest volume. Here, the flow path section Fe6 corresponds to the flow path section that opens on the side opposite to the holding surface 10f of the gas flow path section Fe, and the flow path section Fe1 corresponds to the flow path section that opens on the side of the gas flow path section Fe that opens on the side of the holding surface 10f of the gas flow path section Fe. Similarly to the flow path sections F1 to F6 of the first embodiment, the flow path sections Fe1 to Fe6 correspond to three first flow path sections and three second flow path sections. Therefore, the size of the first or second flow path section that opens on the side opposite to the holding surface 10f of the gas flow path section Fe (flow path section Fe6) is larger than the size of the first or second flow path section that opens on the side of the gas flow path section Fe that opens on the side of the holding surface 10f of the gas flow path section Fe (flow path section Fe1).

[0047] The electrostatic chuck 1e of the sixth embodiment described above can also achieve the same effects as the electrostatic chuck 1 of the first embodiment. Furthermore, in the electrostatic chuck 1e of the sixth embodiment, the volume of the flow passage portion Fe6 that opens on the side opposite to the holding surface 10f side of the gas flow passage portion Fe is relatively large, so that the inflow amount of the inert gas into the gas flow passage portion Fe can be secured. Furthermore, the volume of the flow passage portion Fe1 that opens on the holding surface 10f side of the gas flow passage portion Fe is relatively small, so that electrons contained in the inert gas flowing through the gas flow passage portion Fe are likely to hit the inner surface of the flow passage portion Fe1 and are difficult to accelerate, so that the gas can be supplied to the holding surface 10f side while suppressing the occurrence of arc discharge.

[0048] <Modifications of this embodiment> The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit and scope of the invention. For example, the following modifications are also possible.

[0049] In each of the above-described embodiments, the gas flow passages F, Fe are formed in the plate-shaped member 10 by fitting the laminates L, Le into the plate-shaped member 10, but this is not limiting. For example, the gas flow passages F, Fe may be directly formed in the plate-shaped member 10.

[0050] In the third embodiment, the gas flow path section Fb1 communicates with the other gas flow path section Fb2 via the connection flow path CM, but this is not limited thereto. For example, the gas flow path section Fb1 may communicate with the other gas flow path section Fb2 by directly contacting a flow path section constituting the gas flow path section Fb1 with a flow path section constituting the other gas flow path section Fb2, without the connection flow path CM or the like.

[0051] In the above-described fifth embodiment, the conductive member 18 is provided in the vicinity of the gas flow path section F to suppress the generation of a potential difference between the holding surface side and the opposite side of the gas flow path section F when high-frequency power is applied, but the present invention is not limited to this. For example, instead of providing the conductive member 18 in the vicinity of the gas flow path section F, the inner surface of each of the gas flow path sections F may be covered with a plating layer. In other words, the inner surface of each of the flow path sections F1 to F6 constituting the gas flow path section F may be covered with a plating layer.

[0052] In the fifth embodiment, the conductive member 18 is exemplified as a cylindrical member or a rod-shaped member, but is not limited thereto. For example, the conductive member 18 may be a member in which pads and vias are alternately connected along the vertical direction.

[0053] In the sixth embodiment, the flow path sections Fe1 to Fe6 that are disposed closer to the -Z axis direction have larger volumes, but this is not limited to the above. For example, on the premise that the volume of the flow path section Fe6 is larger than the volume of the flow path section Fe1, the volume of each of the flow path sections Fe1 to Fe6 may be any size as long as the volume of one of the adjacent flow path sections that is closer to the holding surface 10f is equal to or smaller than the volume of the other flow path section that is farther from the holding surface 10f than the one flow path section, among the flow path sections Fe1 to Fe6.

[0054] In the above embodiment, the flow path sections F1 to F6 and the flow path sections Fe1 to Fe6 are cylindrical through holes, but are not limited to this. As long as the flow path sections F1 to F6 and the flow path sections Fe1 to Fe6 are through holes extending in the vertical direction, the cross-sectional shapes of the ends of the flow path sections may be any shape. Furthermore, the cross-sectional shapes of the ends of the flow path sections constituting the gas flow path section F and the gas flow path section Fe do not all need to be the same, and some or all of them may be different.

[0055] In the above-described embodiments, each gas flow path section is composed of six or eight flow path sections, but is not limited thereto. The gas flow path section may be composed of two or more flow path sections. For example, when the gas flow path section is composed of two flow path sections, one of the flow path sections corresponds to the first flow path section, and the other flow path section corresponds to the second flow path section.

[0056] Although the present aspect has been described above based on the embodiment and modified examples, the above-mentioned embodiment of the aspect is intended to facilitate understanding of the present aspect and does not limit the present aspect. The present aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents are included in the present aspect. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate.

[0057] The present invention can also be realized in the following forms. [Application example 1] A holding member for holding an object, A plate-like member having a holding surface for holding the object; a gas flow path portion formed in the plate-like member and capable of passing a gas from an opposite side to the holding surface toward the holding surface, The gas flow path portion is A first flow path portion extending in a direction perpendicular to the holding surface; a second flow path portion extending in the vertical direction and communicating with the first flow path portion, A retaining member, characterized in that, among a first transverse cross-section which is a transverse cross-section of an end of the first flow path section and a second transverse cross-section which is a transverse cross-section of an end of the second flow path section, adjacent first transverse cross-sections and second transverse cross-sections overlap without one containing the other when viewed transparently from the vertical direction. [Application example 2] The holding member according to Application Example 1, A plurality of gas flow passages are formed in the plate-like member, A holding member, wherein at least some of the gas flow passage portions have portions that overlap with other of the gas flow passage portions when viewed in the perpendicular direction. [Application example 3] The holding member according to Application Example 1 or Application Example 2, A plurality of gas flow passages are formed in the plate-like member, A holding member, wherein at least some of the gas flow passage portions communicate with other of the gas flow passage portions. [Application example 4] The holding member according to any one of Application Examples 1 to 3, further comprising: A holding member, comprising: a conductive member extending along the vertical direction provided near the gas flow path portion. [Application example 5] The holding member according to any one of Application Examples 1 to 4, a volume of the first flow path portion or the second flow path portion that opens to the opposite side of the gas flow path portion is larger than a volume of the first flow path portion or the second flow path portion that opens to the holding surface side of the gas flow path portion. [Application Example 6] 1. An electrostatic chuck comprising: A holding member according to any one of Application Examples 1 to 5, and an electrostatic electrode that generates an electrostatic attractive force on the holding surface. [Explanation of symbols]

[0058] 1, 1a to 1e...Electrostatic chuck 10...Plate-shaped member 10f…Holding surface 12...Ring-shaped protrusion 14…Convex part 16…Recess 18...Conductive material 20...Base member 25…AC power supply 30...Adhesive material 40...Electrostatic electrode 45...Metal terminal Eg…Outer edge F, Fa, Fb1-Fb5, Fc1-Fc5, Fe...Gas passage section F1~F6, Fa1~Fa8, Fe1~Fe6...flow path G1~G6, Ge1~Ge6...Green sheets H...Holding member H1...1st through hole H2…Second through hole H3...Third through hole HL...Through hole L, Le…Laminate Sa3, Sa4, Sd1, Sd2, Su2, Su3...cross sections

Claims

1. A holding member for holding an object, A plate-like member having a holding surface for holding the object; a gas flow path portion formed in the plate-like member and capable of passing a gas from an opposite side to the holding surface toward the holding surface, The gas flow path portion is A first flow path portion extending in a direction perpendicular to the holding surface; a second flow path portion extending in the vertical direction and communicating with the first flow path portion, A retaining member, characterized in that, among a first transverse cross-section which is a transverse cross-section of an end of the first flow path section and a second transverse cross-section which is a transverse cross-section of an end of the second flow path section, adjacent first transverse cross-sections and second transverse cross-sections overlap without one containing the other when viewed transparently from the vertical direction.

2. 2. The holding member according to claim 1, A plurality of gas flow passages are formed in the plate-like member, A holding member, wherein at least some of the gas flow passage portions have portions that overlap with other of the gas flow passage portions when viewed in the perpendicular direction.

3. 2. The holding member according to claim 1, A plurality of gas flow passages are formed in the plate-like member, A holding member, wherein at least some of the gas flow passage portions communicate with other of the gas flow passage portions.

4. The retaining member according to claim 1 , further comprising: A holding member, comprising: a conductive member extending along the vertical direction provided near the gas flow path portion.

5. 2. The holding member according to claim 1, a volume of the first flow path portion or the second flow path portion that opens to the opposite side of the gas flow path portion is larger than a volume of the first flow path portion or the second flow path portion that opens to the holding surface side of the gas flow path portion.

6. 1. An electrostatic chuck comprising: A holding member according to any one of claims 1 to 5; and an electrostatic electrode that generates an electrostatic attractive force on the holding surface.

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