Holding member and electrostatic chuck

Abstract

A holding member is provided that suppresses arc discharge while 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; 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; and 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 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] Electrostatic chucks that use electrostatic attraction to hold a wafer are known as holding members for holding an object. For example, Patent Document 1 discloses an electrostatic chuck that includes multiple ceramic layers that are wafer ceramics to be placed under a wafer, and in which flow paths with multiple bends are formed by notches in each ceramic layer. The flow paths thus formed suppress the acceleration of electrons contained in gas flowing through the flow paths, thereby suppressing 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] The flow path disclosed in Patent Document 1 has multiple bends, which tends to increase the length of the flow path that the gas must pass through before reaching the wafer, leading to reduced gas supply efficiency. Furthermore, the flow path disclosed in Patent Document 1 tends to require a large amount of space within the wafer ceramic to accommodate the flow path, which limits the placement of other components within the wafer ceramic. For this reason, there has been a demand for the development of a holding member that can reduce the flow path length and save space while suppressing arc discharge.

[0005] The present invention has been made to solve at least some of the above-mentioned problems, and aims to provide a holding member that suppresses arc discharge while shortening the flow path length and saving space for 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 toward the holding surface, 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, of a first transverse cross section which is a cross section of an end portion of the first flow path portion and a second transverse cross section which is a cross section of an end portion of the second flow path portion, adjacent first and second transverse cross sections overlap each other without enclosing one within the other when viewed in the perpendicular direction.

[0008] According to this configuration, adjacent first and second transverse sections overlap without enclosing one another when viewed vertically. That is, a vertically oriented surface is disposed around the overlapping portion of the adjacent first and second transverse sections. Therefore, electrons contained in the gas flowing through the gas flow passage section are more likely to strike this surface, and the acceleration of the electrons striking this surface is suppressed, thereby suppressing the occurrence of arc discharge. Furthermore, according to this configuration, since both the first and second flow passage sections extend vertically, the gas flow path length required to reach the holding surface can be shortened compared to a gas flow passage section with multiple bends or a porous gas flow passage section. Furthermore, since both the first and second flow passage sections extend vertically, the space required to arrange the gas flow passage sections within the plate-shaped member can be reduced. Therefore, according to this configuration, a holding member can be provided that suppresses arc discharge while shortening the flow path length of the gas flow passage section and saving space for the gas flow passage section.

[0009] (2) In the holding member of the above aspect, a plurality of gas flow path sections may be formed within the plate-like member, and at least some of the gas flow path sections may have portions that overlap with other gas flow path sections when viewed in the vertical direction. With this configuration, since multiple gas flow passages are formed in the plate-shaped member, gas can be efficiently supplied to the holding surface side. Also, with this configuration, the multiple gas flow passages can be arranged close to each other, thereby saving space within the plate-shaped 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 of the gas flow passages. With this configuration, since multiple gas flow paths are formed in the plate-like member, gas can be efficiently supplied to the holding surface side. Furthermore, with this configuration, even if gas flow is obstructed in one gas flow path due to clogging with particles or the like, gas can still be circulated to other gas flow paths that are connected to it, thereby preventing a decrease in gas supply efficiency.

[0011] (4) In the holding member of the above aspect, a conductive member extending along the vertical direction may be provided in the vicinity of the gas flow path portion. 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 of the plate member opposite to the holding surface side, it is possible to prevent a potential difference from occurring between the holding surface side of the gas flow path and the opposite side, thereby further preventing arc discharge.

[0012] (5) In the holding member of the above aspect, the volume of the first flow path portion or the second flow path portion of the gas flow path portion that opens to the opposite side may be larger than the volume of the first flow path portion or the second flow path portion of the gas flow path portion that opens to the holding surface side. With this configuration, the first or second gas flow path portion that opens on the side opposite to the holding surface has a relatively large volume, ensuring a sufficient amount of gas flowing into the gas flow path portion. Furthermore, the first or second gas flow path portion that opens on the holding surface has a relatively small volume, making it difficult for electrons contained in the gas flowing through the gas flow path portion to accelerate. This allows gas to be supplied to the holding surface side while suppressing arc discharge.

[0013] (6) According to another aspect of the present invention, there is provided an electrostatic chuck, comprising: a 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, when power is supplied to the electrostatic electrode, an electrostatic attraction (adsorption force) is generated, and the object can be held on the holding surface side by this electrostatic attraction. In addition, since the gas flow path portion has the first flow path portion and the second flow path portion, it is possible to provide an electrostatic chuck that suppresses the occurrence of arc discharge, improves the efficiency of supplying gas to the holding surface side, and saves space for the gas flow path portion.

[0014] The present invention can be realized in various forms, for example, a holding member, an electrostatic chuck including an electrostatic electrode that generates electrostatic attraction between the holding member and the holding surface of the holding member, a vacuum chuck, a ceramic heater, a semiconductor manufacturing apparatus, a component including any of these, and a manufacturing method for these. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is an explanatory view schematically illustrating a cross-sectional configuration of an electrostatic chuck according to a first embodiment. [Figure 2] FIG. 4 is an explanatory diagram of a gas flow path portion. [Figure 3] FIG. 4 is an explanatory view showing a flow path portion when viewed through the laminate. [Figure 4] FIG. 10 is an explanatory view showing a gas flow path portion in an electrostatic chuck according to a second embodiment. [Figure 5] FIG. 10 is an explanatory view showing a gas flow path portion in an electrostatic chuck according to a third embodiment. [Figure 6] FIG. 10 is an explanatory view showing a gas flow path portion in an electrostatic chuck according to a fourth embodiment. [Figure 7] FIG. 10 is an explanatory view schematically showing a cross-sectional configuration of an electrostatic chuck according to a fifth embodiment. [Figure 8] FIG. 10 is an explanatory view of a gas flow path portion in an electrostatic chuck according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] First Embodiment FIG. 1 is an explanatory diagram schematically illustrating a 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 attracts 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 identify directions. In FIG. 1, the semiconductor wafer W held by the electrostatic chuck 1 is illustrated 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-like 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 ceramic. 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, which is the 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 protrusion 12, a plurality of protrusions 14, and a plurality of recesses 16. The annular protrusion 12 is formed along the outer edge of the holding surface 10f. Each of the protrusions 14 is formed inside the annular protrusion 12. Each of the recesses 16 is formed between the protrusions 14. In other words, the recesses 16 are formed at positions inside the annular protrusion 12 where no protrusions 14 are formed. When the holding surface 10f is viewed from a direction facing the holding surface 10f (when viewed from above), the recesses 16 are 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 (described later). Materials forming the base member 20 include metals and various composite materials. Examples of metals forming the base member 20 include aluminum (Al), titanium (Ti), and alloys thereof. Examples of composite materials forming the base member 20 include a composite material formed by melting an aluminum alloy (mainly aluminum) into a porous ceramic (mainly silicon carbide (SiC)) and pressurizing the melted aluminum alloy to infiltrate the porous ceramic. The aluminum alloy contained in the composite material may contain silicon (Si) or magnesium (Mg), or may contain other elements as long as they do not affect the properties of the composite material. Furthermore, a coolant flow path may be formed inside the base member 20 to allow a coolant to flow through the base member 20 to cool the semiconductor wafer W 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 supply 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 together. The adhesive member 30 is made of an adhesive material such as a silicone-based resin, an acrylic-based resin, or an epoxy-based 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 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 comes into contact with the annular protrusion 12 and the protrusion 14, thereby being held on the holding surface 10f. With the semiconductor wafer W held on the holding surface 10f, an inert gas such as helium gas is supplied between the semiconductor wafer W and the holding surface 10f to increase thermal conductivity between the semiconductor wafer W and the holding surface 10f. More specifically, the inert gas is supplied toward the holding surface 10f from the opposite side (the −Z-axis side in FIG. 1) from the side of the holding surface 10f (the +Z-axis side in FIG. 1) through through-holes HL, which will be described later. The inert gas supplied to the side of the holding surface 10f flows through the space between the semiconductor wafer W and the recess 16 and diffuses throughout the space.

[0024] Through holes HL are formed inside the electrostatic chuck 1 as flow paths for circulating an inert gas toward the holding surface 10f. The through holes HL are 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 inside the base member 20 along the Z-axis direction. The third through hole H3 is a through hole formed inside the adhesive member 30 along the Z-axis direction and 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 inside the plate-shaped member 10 and 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, which will be described later. The gas flow path section F is formed in the plate-shaped member 10 and is a flow path that can circulate 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-shaped member 10 and the gas flow path section 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 path section F. FIG. 2(A) shows an enlarged view of the periphery of the gas flow path section F in the plate-shaped member 10. FIG. 2(B) shows the state in which the green sheets G1 to G6 defining the gas flow path 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 a flow path section F1 to F6 penetrating the green sheets G1 to G6 is formed in each of the green sheets G1 to G6. Each of the flow path sections F1 to F6 is a cylindrical through-hole extending in a direction perpendicular to the holding surface 10f (the Z-axis direction in FIG. 2), and each of the flow path 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 considered to be a vertical direction at a glance. Each of the central axes X1 to X6 is the central axis of each of the flow path 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 perpendicular to the vertical direction (the XY plane in FIG. 2). Specifically, the central axes X1 to X6 are located at the same position on the Y axis direction but at different positions on the X axis direction. That is, the flow path sections F1 to F6 are located at the same position on the Y axis direction but at different positions on the X axis direction. The maximum length of each of the flow path sections F1 to F6 along the Z axis direction (the length indicated by the double arrow in flow path section F2 in FIG. 2(B)) is preferably 0.25 mm or less, more preferably 0.15 mm or less. Furthermore, the maximum length of two adjacent flow path sections along the Z axis direction (the length indicated by the double arrow in flow path 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, it is possible to sufficiently suppress the occurrence of arc discharge within the gas flow path section F.

[0026] 2, in this embodiment, the gas flow path section F is defined by stacking disk-shaped green sheets G1 to G6. More specifically, the gas flow path section F is defined by the flow path sections F1 to F6 being connected to each other when the disk-shaped green sheets G1 to G6 are stacked. That is, the gas flow path section F has flow path sections F1 to F6. Then, a cylindrical laminate L (see FIG. 2(A)) in which the green sheets G1 to G6 are stacked is fitted 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), whereby the gas flow path section F is disposed within the plate-shaped member 10. In the manufacturing process of the plate-shaped member 10, the pre-fired laminate L may be fitted into the pre-fired plate-shaped member 10 and then fired together with the plate-shaped member 10, or the pre-fired laminate L may be fitted into the fired plate-shaped member 10 and then fired together with the plate-shaped member 10. Alternatively, the fired laminate L may be fitted into the fired plate-shaped member 10. Note that when the laminate L is fired, the boundaries between 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 viewed from a vertical perspective. In Fig. 3, in order to make it easier to see the overlap of the flow path sections F1 and F2, the laminate L viewed from a vertical perspective is not hatched as in Fig. 2. Fig. 3 shows the overlap of the flow path sections F1 and F2 when viewed from a vertical perspective, 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 FIGS. 2A and 2B, the flow path section F1 and the flow path section F2 are adjacent to each other. Furthermore, as shown in FIG. 2B, the cross section Sd1 at the end of the flow path section F1 on the −Z-axis direction side and the cross section Su2 at 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 taken along a plane perpendicular to the central axis of the flow path section. As shown in FIG. 3, the adjacent cross sections Sd1 and Su2 overlap without including one another when viewed in a vertical direction. Similar to the overlapping of the cross sections Sd1 and Su2, adjacent cross sections of adjacent flow path sections among the flow path sections F1 to F6 overlap without including one another.

[0029] Thus, each of the flow path sections F1 to F6 constituting the gas flow path section F corresponds to a first flow path section extending perpendicular to the holding surface 10f and a second flow path section extending perpendicularly 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 either a first flow path section or a 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 first and second flow path sections, of the first cross section that is a cross section of an end of the first flow path section and the second cross section that is a cross section of an end of the second flow path section, adjacent first and second cross sections overlap without containing one another when viewed in a vertically transparent manner. For example, when flow path section F2 is regarded as the first flow path section and flow path sections F1 and F3 are regarded as second flow path sections (see FIG. 2(B)), the cross section Su2 (first cross section) at the end on the +Z axis direction side of flow path section F2 and the cross section Sd1 (second cross section) at the end on the −Z axis direction side of flow path section F1 overlap with the cross section Sd2 (first cross section) at the end on the −Z axis direction side of flow path section F2 and the cross section Su3 (second cross section) at the end on the +Z axis direction side of flow path section F3, respectively, without containing one another when viewed in a vertically transparent manner.

[0030] According to the electrostatic chuck 1 of the first embodiment described above, adjacent cross sections of the end portions of the flow path portions F1 to F6 overlap each other without enclosing one cross section within the other when viewed in a vertical direction. That is, a vertically oriented surface VP (see FIG. 2(A)) is disposed around the overlapping portion of the cross sections of the adjacent end portions. Therefore, electrons contained in the inert gas flowing through the gas flow path portion F are likely to strike the surface VP, and the acceleration of the electrons striking the surface VP is suppressed, thereby suppressing the occurrence of arc discharge. Furthermore, according to the electrostatic chuck 1 of the first embodiment, each of the flow path portions F1 to F6 corresponding to the first and second flow path portions extends vertically. Therefore, compared to a gas flow path portion having multiple bends or a porous gas flow path portion, the length of the flow path through which the inert gas passes before reaching the holding surface 10f can be shortened. 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 design for the 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 according to the second embodiment is the same as the electrostatic chuck 1 according to the first embodiment (see FIG. 1) except that the shape of the gas flow path portion Fa formed in the 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 as seen vertically, similar to FIG. 3. FIG. 4(B) is a perspective view of the gas flow path section Fa. To make the shape of the gas flow path section Fa easier to see, FIGS. 4(A) and 4(B) do not show the laminate (green sheet) surrounding the gas flow path section Fa. The gas flow path section Fa of the second embodiment has a spiral shape, as shown in FIG. 4(B). That is, the flow path sections Fa1 to Fa8 constituting the gas flow path section Fa are each arranged in a spiral shape. Note that while FIG. 3 shows the outer edge Eg of the flow path section F2 visible from the inside of the flow path section F1, FIG. 4(A) does not show the outer edge of one of the adjacent flow path sections that is visible from the inside of the other flow path section to make the drawing easier to see. For example, the outer edge of the flow path section Fa1 visible from the inside of the flow path section Fa2 is not shown, and the outer edges of the flow path sections Fa2 to Fa7 visible from the inside of the flow path sections Fa3 to Fa8 are also not shown. Like the flow path sections F1 to F6 of the first embodiment, each of the flow path sections Fa1 to Fa8 corresponds to four first flow path sections and four second flow path sections, and adjacent cross sections of the end sections of each of the flow path sections Fa1 to Fa8 overlap with each other without enclosing one within the other when viewed in a vertical direction. Figure 4(B) shows cross sections Sa3 and Sa4 as examples of two overlapping cross sections without enclosing 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 to Fb5 in an electrostatic chuck 1b according to a third embodiment of the present invention. The electrostatic chuck 1b according to the third embodiment is the same as the electrostatic chuck 1a according to the second embodiment (see FIG. 4) except that a plurality of spiral gas flow passage portions Fb1 to Fb5 are formed in the plate-shaped member 10.

[0035] FIG. 5 shows the gas flow path sections Fb1 to Fb5 as seen through in a vertical direction. To make the shape of each of the gas flow path sections Fb1 to Fb5 easier to see, similar to FIG. 4, FIG. 5 does not show the laminates (green sheets) surrounding the gas flow path sections Fb1 to Fb5. Each of the gas flow path sections Fb1 to Fb5 of the third embodiment has a spiral shape, similar to the gas flow path section Fa of the second embodiment (see FIG. 4). Each of the gas flow path sections Fb1 to Fb5 formed in the plate-like member 10 has a portion that overlaps with the other gas flow path sections Fb1 to Fb5 when seen through in a vertical direction (Z-axis direction). In FIG. 5, the portion that overlaps with the other gas flow path sections Fb1 to Fb5 is hatched with dots. Furthermore, the gas flow path section Fb1 is in communication with the other gas flow path section Fb2 via a connecting flow path 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 to Fb5 has a portion that overlaps with another gas flow passage portion Fb1 to Fb5 when viewed in a vertically transparent manner. Therefore, the gas flow passage portions Fb1 to Fb5 can be arranged close to each other, thereby reducing the space required for the gas flow passage portions Fb1 to Fb5 within the plate-shaped member 10.

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

[0039] <Fourth embodiment> FIG. 6 is an explanatory diagram showing gas flow passage portions Fb1-Fb5 and gas flow passage portions Fc1-Fc5 in an electrostatic chuck 1c according to a fourth embodiment of the present invention. The electrostatic chuck 1c of the fourth embodiment is the same as the electrostatic chuck 1b of 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-Fc5 are formed in addition to the plurality of spiral gas flow passage portions Fb1-Fb5 within the plate-shaped member 10. Each of the gas flow passage portions Fc1-Fc5 is disposed between the gas flow passage portions Fb1-Fb5. As shown in FIG. 6, each of the gas flow passage portions Fc1-Fc5 has a portion that overlaps with the gas flow passage portions Fb1-Fb5 when viewed in a 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 to Fb5, Fc1 to 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 schematically 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 1d according to the first embodiment.

[0042] The conductive member 18 is provided near the gas flow path section F and extends along the vertical direction (the Z-axis direction in FIG. 7 ). “Near” here refers to a certain range from the gas flow path section F. For example, the conductive member 18 is disposed closer to the gas flow path section F than the electrostatic electrode 40 in a plane perpendicular to the vertical direction (the XY plane in FIG. 7 ). In the present embodiment, the conductive member 18 is a cylindrical member that surrounds the gas flow path section F. However, the conductive member 18 may be, for example, a rod-shaped member as long as it is provided near the gas flow path section F and extends along the vertical direction. In the present embodiment, the end of the conductive member 18 on the +Z-axis direction side is not exposed on the holding surface 10f, but the end may be exposed on the holding surface 10f. In the present embodiment, the end of the conductive member 18 on the −Z-axis side is connected to the base member 20. However, if the adhesive member 30 is a metallic adhesive and thus conductive, 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 the upper electrode (not shown) positioned on the +Z-axis direction side of the holding surface 10f and the base member 20 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 near the gas flow path portion F. Therefore, when high-frequency power is applied from the side opposite to the holding surface 10f 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 arc discharge.

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

[0046] FIG. 8(A) shows the laminate Le fitted in the plate-shaped member 10. FIG. 8(B) shows the state in which the green sheets Ge1 to Ge6 defining the gas flow path section Fe are separated. The laminate Le is a cylindrical laminate formed by stacking green sheets Ge1 to Ge6. Each of the green sheets Ge1 to Ge6 has a substantially identical disk shape and substantially the same thickness, and each of the flow path sections Fe1 to Fe6 is formed therein. Each of the flow path sections Fe1 to Fe6 is a cylindrical through-hole. The flow path sections Fe1 to Fe6 have different volumes. Specifically, the flow path sections Fe1 to Fe6 closer to the -Z-axis direction have larger volumes. That is, among the flow path sections Fe1 to Fe6, the flow path section Fe1 has the smallest volume, and the flow path section Fe6 has the largest volume. Here, the flow path section Fe6 corresponds to the flow path section of the gas flow path section Fe that opens on the side opposite to the holding surface 10f, and the flow path section Fe1 corresponds to the flow path section of the gas flow path section Fe that opens on the side of the holding surface 10f. 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 of the gas flow path section Fe that opens on the side opposite to the holding surface 10f (flow path section Fe6) is larger than the size of the first or second flow path section of the gas flow path section Fe that opens on the side of the holding surface 10f (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 path portion Fe6 that opens on the side opposite to the holding surface 10f of the gas flow path portion Fe is relatively large, so that the amount of inert gas that flows into the gas flow path portion Fe can be ensured. Furthermore, the volume of the flow path portion Fe1 that opens on the holding surface 10f side of the gas flow path portion Fe is relatively small, so that electrons contained in the inert gas flowing through the gas flow path portion Fe are likely to hit the inner surface of the flow path portion Fe1 and are not easily accelerated. Therefore, it is possible to supply gas to the side of the holding surface 10f while suppressing the occurrence of arc discharge.

[0048] <Modification 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 of the invention. For example, the following modifications are also possible.

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

[0050] In the third embodiment, the gas flow path portion Fb1 communicates with another gas flow path portion Fb2 via the connecting flow path CM, but this is not limiting. For example, the gas flow path portion Fb1 may communicate with another gas flow path portion Fb2 by directly contacting a flow path portion constituting the gas flow path portion Fb1 with a flow path portion constituting the other gas flow path portion Fb2, without the intervention of the connecting flow path CM or the like.

[0051] In the fifth embodiment, the conductive member 18 is provided near the gas flow path section F to prevent a potential difference from occurring 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 near the gas flow path section F, the inner surface of each of the gas flow path sections F may be coated with a plating layer. In other words, the inner surface of each of the flow path sections F1 to F6 that constitute the gas flow path section F may be coated 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 closer to the -Z-axis direction have larger volumes, but this is not limited to this. For example, on the premise that the volume of flow path section Fe6 is larger than the volume of flow path section Fe1, the volume of each of flow path sections Fe1 to Fe6 may be any size as long as the volume of one of adjacent flow path sections that is closer to holding surface 10f is equal to or smaller than the volume of the other flow path section that is farther from 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 this is not limited thereto. The flow path sections F1 to F6 and the flow path sections Fe1 to Fe6 may have any cross-sectional shape at their ends as long as they are through-holes extending in the vertical direction. Furthermore, the cross-sectional shapes at the ends of the flow path sections constituting the gas flow path section F and the gas flow path section Fe do not all have to be the same, and some or all of them may be different.

[0055] In the above embodiments, each gas flow path section is composed of six or eight flow path sections, but this 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 flow path section corresponds to the first flow path section and the other flow path section corresponds to the second flow path section.

[0056] This aspect has been described above based on embodiments and modifications. However, the above-described embodiments are intended to facilitate understanding of this aspect and are not intended to limit this aspect. This aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents thereof are included in this 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-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 is a first flow path portion extending perpendicular to the holding surface; a second flow path portion extending in the vertical direction and communicating with the first flow path portion, A holding member characterized in that, of a first transverse section which is a transverse section of an end of the first flow path section and a second transverse section which is a transverse section of an end of the second flow path section, adjacent first transverse sections and second transverse 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 path sections have portions that overlap with other of the gas flow path sections 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 sections are in communication with other of the gas flow passage sections. [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 of the gas flow path portion that opens to the opposite side is larger than a volume of the first flow path portion or the second flow path portion of the gas flow path portion that opens to the holding surface side. [Application Example 6] An electrostatic chuck, A holding member according to any one of Application Examples 1 to 5; 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 to Fb5, Fc1 to Fc5, Fe...gas passage section F1~F6, Fa1~Fa8, Fe1~Fe6...flow path section 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 section

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-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 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 holding member characterized in that, of a first transverse section which is a transverse section of an end of the first flow path section and a second transverse section which is a transverse section of an end of the second flow path section, adjacent first transverse sections and second transverse sections overlap without one containing the other when viewed transparently from the vertical direction.

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 path sections have portions that overlap with other of the gas flow path sections when viewed in the perpendicular direction.

3. 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 sections are in communication with other of the gas flow passage sections.

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

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

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