JP2023061525A - holding device - Google Patents

Abstract

To provide a holding device in which the occurrence of abnormal discharge is reduced.SOLUTION: A holding device includes a plate-shaped member, a base member, and a bonding material. A gas flow channel inside the plate-shaped member 10 includes a plane parallel gas flow channel 60T extending parallel to a first surface S1, and a gas outflow channel 60V1 and a gas inflow channel 60V2 that connect a gas outflow hole 61 or a gas inflow hole 62 and the plane parallel gas flow channel 60T. Between the plane parallel gas flow channel and the first surface S1 or a second surface S2, a first electrode 51 including a first penetration hole 51H through which the gas outflow channel 60V1 is inserted with a predetermined distance D1 and a second electrode 52 including a second penetration hole 52H through which the gas inflow channel 60V2 is inserted with a predetermined distance D2 are provided. Inside the gas flow channel are provided a gas outflow-inflow channel porous body part 70V disposed inside any gas outflow channel, and a parallel flow channel porous body part 70T disposed inside the plane parallel gas flow channel so as to overlap the first penetration hole or the second penetration hole in a view in a normal direction of the first surface.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to retention devices.

As an example of the holding device, an electrostatic chuck described in Patent Document 1 below is known. This electrostatic chuck includes a plate having a first surface and a second surface, a first electrode embedded in the plate near the first surface, a second electrode embedded in the plate near the second surface, a first a plurality of electrical conductors connecting the electrode and the second electrode; a first gas flow path arranged in the plate between the first electrode and the second electrode; and a first gas flow path from the second surface of the plate. and a plurality of gas outlet channels extending from the first surface of the plate to the first gas channel. When performing plasma processing on a substrate, wafer, or the like, an electrostatic chuck is placed inside a plasma processing chamber or the like in such a posture that the first surface of the plate is the upper surface and the second surface is the lower surface. Hold the board, etc. Then, high-frequency power is applied to a metallic cooling plate arranged below the plate to generate plasma and a bias voltage to the substrate and the like. In addition, in order to improve the temperature controllability of the substrate held on the plate first surface side, a thermally conductive gas such as helium is sent from the second surface side to the first surface side through the gas flow path in the plate. be done.

WO2020/185395

In recent years, high-frequency power applied during plasma processing has been increased in order to speed up processing. As a result, the potential difference between the cooling plate and the substrate or the like increases, increasing the possibility of unintended abnormal electrical discharge (arcing) occurring in the gas flow path. If abnormal discharge occurs, the processing quality of substrates and the like deteriorates and the yield decreases. Therefore, there is a demand for a technique for reducing the occurrence of abnormal discharge in the flow path without interfering with gas supply. As an example, in a portion of the gas channel extending from the gas inflow hole and the gas outflow hole in a direction intersecting the holding surface for holding the substrate (the portion corresponding to the gas inflow channel and the gas outflow channel in Patent Document 1), For example, it is known that the occurrence of abnormal discharge can be reduced by arranging an insulating porous body. In addition, the portion extending parallel to the holding surface (the portion corresponding to the first gas flow path in Patent Document 1) is arranged with electrodes (first electrode and second electrode in Patent Document 1) above and below it, thereby Discharge countermeasures are possible.

However, the electrodes arranged above and below the portion extending parallel to the holding surface cannot be arranged in the vicinity of the gas inflow path and the gas outflow path from the viewpoint of ensuring insulation and avoiding discharge in the gas flow path. . As a result, there are areas near the gas inflow path and the gas outflow path that do not have the electrodes arranged above and below. In the conventional method, measures against abnormal discharge could not be taken for this region.

In view of the above situation, an object of the present technology is to provide a holding device that enables countermeasures against abnormal discharge in a conventionally difficult area and further reduces the occurrence of abnormal discharge.

A holding device according to the present disclosure includes an insulating plate-like member having a first surface for holding an object and a second surface located on the opposite side of the first surface, the inside of the plate-like member is connected to a plane-parallel gas channel extending parallel to the first surface and a first connection hole provided in a wall surface of the plane-parallel gas channel, the first surface a gas outflow passage that communicates between a gas outflow hole provided in the second surface and the plane-parallel gas flow passage; a gas flow channel that communicates between the gas flow hole and the plane-parallel gas flow channel; and a first electrode disposed between the first surface and the plane-parallel gas flow channel. , a second electrode disposed between the second surface and the plane-parallel gas flow path, and the first electrode includes a wall surface of the gas flow path between the first electrode and the wall surface of the gas flow path. A first through hole through which the gas outflow passage is inserted is formed at a predetermined interval, and the second electrode is provided with a predetermined interval between the second electrode and the wall surface of the gas inflow passage. A second through hole is formed through which the gas inflow path is inserted, and an insulating porous body is disposed inside the gas flow path, and the porous body is at least one of the gas outflow path and the gas inflow path. and the plane-parallel gas flow path so as to overlap the first through-hole or the second through-hole when viewed from the normal direction of the first surface. and an intra-parallel flow channel porous body portion arranged inside the holding device.

According to the present disclosure, it is possible to provide a holding device with reduced occurrence of abnormal discharge.

FIG. 1 is a perspective view schematically showing a schematic configuration with a part of the holding device according to the embodiment cut away. FIG. 2 is a cross-sectional view schematically showing the outline of the internal structure of the plate member. 3 is a cross-sectional view showing an enlarged part of FIG. 2. FIG. FIG. 4 is a cross-sectional view showing an enlarged vicinity of a porous body arrangement region of a plate member according to a reference example. FIG. 5 is a cross-sectional view showing an enlarged portion of a plate-shaped member where a porous body is provided according to another embodiment.

[Description of Embodiments of the Present Disclosure]
First, the embodiments of the present disclosure are listed.
<1> A holding device of the present disclosure includes an insulating plate-like member having a first surface for holding an object and a second surface located on the opposite side of the first surface, the plate-like member is connected to a plane-parallel gas channel extending parallel to the first surface and a first connecting hole provided on a wall surface of the plane-parallel gas channel, the first a gas outflow passage connecting a gas outflow hole provided on one surface and the plane-parallel gas flow passage; a gas flow path that communicates between a gas flow hole provided in the surface and the plane-parallel gas flow path; and a first gas flow path arranged between the first surface and the plane-parallel gas flow path an electrode and a second electrode disposed between the second surface and the plane-parallel gas flow path; A first through hole through which the gas outflow path is inserted is formed with a predetermined gap therebetween, and the second electrode has a predetermined gap between the second electrode and the wall surface of the gas inflow path. a second through hole through which the gas inflow path is inserted is formed in the gas flow path, and an insulating porous body is disposed inside the gas flow path, and the porous body is the gas outflow path or the gas inflow path. and the plane-parallel gas so as to overlap the first through hole or the second through hole when viewed from the normal direction of the first surface. and an intra-parallel flow path porous body portion arranged inside the flow path.

<2> In the holding device of <1> above, the plane-parallel gas flow path is provided with an empty region where the porous body is not disposed.

<3> In the holding device of <1> or <2> above, the first connection hole and the second connection hole are provided at positions that do not overlap each other when viewed from the normal direction of the first surface. .

<4> In the holding device according to any one of <1> to <3> above, the porous body overlaps the first through hole when viewed from the normal direction of the first surface. A first porous body arranged in a region extending from the inside of the gas outflow channel to the inside of the plane-parallel gas channel, and the second through hole so as to overlap the entirety of the second through hole when viewed from the normal direction of the first surface. and a second porous body arranged in a region extending from the inside of the gas inlet channel to the inside of the plane-parallel gas channel.

<5> In the holding device according to any one of <1> to <3> above, the parallel flow path inner porous body portion includes a portion of the porous body that is continuous with the inflow/outflow path inner porous body portion, It is formed by protruding from the first connection hole or the second connection hole into the plane-parallel gas flow path.

[Details of the embodiment of the present disclosure]
A specific example of the holding device of the present disclosure will be described below with reference to the drawings. The present disclosure is not limited to these examples, but is indicated by the scope of the claims, and is intended to include all modifications within the meaning and scope of equivalents of the scope of the claims. Part of each drawing shows the X-axis, Y-axis, and Z-axis of an orthogonal coordinate system XYZ, and the directions of the axes are drawn in the same direction in each drawing. In the following description, the upper side of the paper surface in FIG. 1 is the upper side of the paper surface, and the upper side of FIGS. 2 to 5 is the upper side. I have something to do. In addition, the relative size and arrangement of members in each drawing are not necessarily accurate, and some members have been changed in scale for convenience of explanation. In the following description, "parallel" and "perpendicular" do not necessarily have such a positional relationship, and "substantially parallel" and "substantially orthogonal" are used as long as they do not deviate from the gist of the present disclosure. shall include

<Details of embodiment>
A holding device 100 according to the present embodiment will be described below with reference to FIGS. 1 to 4. FIG. The holding device 100 is an electrostatic chuck that attracts and holds an object (eg, semiconductor wafer W) by electrostatic attraction while heating the object (eg, semiconductor wafer W) to a predetermined processing temperature (eg, 50° C. to 400° C.). An electrostatic chuck is used as a table on which a wafer W is placed in a process such as etching using plasma in a decompressed chamber.

FIG. 1 is a diagram schematically showing a schematic configuration of a holding device 100. As shown in FIG. The holding device 100 includes a disk-shaped plate-shaped member 10 and a similarly disk-shaped base member 20 . The diameter of the base member 20 is larger than that of the plate-like member 10. For example, when the plate-like member 10 has a disc shape of 300 mm in diameter and 3 mm in thickness, the base member 20 can be in the shape of a disc of 340 mm in diameter and 20 mm in thickness. can. Both the plate-like member 10 and the base member 20 are generally disk-shaped, and may be provided with unevenness or the like for alignment. The plate-shaped member 10 and the base member 20 are arranged in the vertical direction (Z-axis direction) and are joined by the joining material 30 . A first surface S1 on the upper side of the plate member 10 serves as an attraction surface for attracting and holding the wafer W, and a second surface S2 on the lower side of the plate member 10 is bonded to the base member 20 via the bonding material 30. be done. The first surface S1 on the upper side of the plate member 10 may be an uneven surface including protrusions for placing the wafer W thereon.

As shown in FIG. 2, the plate member 10 is arranged such that its first surface S1 and second surface S2 are substantially perpendicular to the vertical direction (Z-axis direction). The plate-like member 10 is an insulating substrate, and is made of, for example, ceramics containing aluminum nitride (AlN) or alumina (Al ₂ O ₃ ) as a main component. In addition, the main component here means the component with the highest content ratio (weight ratio).

As shown in FIGS. 1 and 2, a plurality of gas outflow holes 61 are provided in the first surface S1 of the plate member 10, and gas inflow holes 62 are provided in the second surface S2. A gas passage 60 is formed inside the plate-like member 10 so as to allow the fluid to communicate between the gas outlet hole 61 and the gas inlet hole 62 . The outer peripheral edge of the first surface S1 is formed to protrude slightly higher than the inner peripheral portion. A gap G is formed between the wafer W and the first surface S1.

A thermally conductive gas such as helium gas is caused to flow through the gas flow path 60 of the plate member 10 . The gas injected into the gas inflow hole 62 from the gas injection path 23 of the base member 20 (to be described later) flows through the gas flow path 60 and out of the gas outflow hole 61, and flows into the gap G between the plate member 10 and the wafer W. be filled. Thereby, the temperature of the first surface S1 is easily transmitted to the wafer W, and the temperature controllability of the wafer W is improved. The internal configuration of the plate member 10 including the gas flow paths 60 will be described later.

As the bonding material 30, for example, a silicone-based organic bonding agent, an inorganic bonding agent, or a bonding sheet containing an Al-based metal adhesive can be used. The bonding material 30 preferably has high adhesive strength to both the plate-shaped member 10 and the base member 20, and also has high heat resistance and thermal conductivity. A hole is provided in the bonding material 30 at a position facing the gas inlet hole 62 formed in the plate member 10 and communicating with the gas injection passage 23 formed in the base member 20 described later. This allows the gas injected into the gas injection path 23 to flow through the hole inside the bonding material 30 to the gas flow path 60 .

The base member 20 is joined to the lower side of the plate member 10, ie, the second surface S2 side, with a joining material 30, as shown in FIG. The base member 20 is a conductive base material, and can be composed mainly of, for example, aluminum, an aluminum alloy, a composite of metal and ceramics (Al--SiC), or ceramics (SiC). When plasma processing the wafer W, a bias voltage is generated on the wafer W by applying high-frequency power to the base member 20 . As described above, the base member 20 has a disc shape with a diameter larger than that of the plate-like member 10, and the entire plate-like member 10 is placed thereon.

As shown in FIG. 1, a coolant passage 21 is formed inside the base member 20 . Plasma heat is cooled by flowing a coolant such as water or fluorine-based inert liquid through the coolant path 21 . When the coolant flows through the coolant path 21, the base member 20 is cooled, the plate member 10 is cooled by heat conduction via the bonding material 30, and the wafer W held on the first surface S1 of the plate member 10 is cooled. Cooled. The temperature of the wafer W can be controlled by adjusting the coolant flow.

As shown in FIG. 1, the inside of the base member 20 is also provided with a gas injection passage 23 through which a fluid can move. The gas injection path 23 is open to the lower surface of the base member 20 and communicates with the gas flow path 60 of the plate member 10 through the hole in the bonding material 30 . A conductive gas is injected.

Next, the configuration inside the plate member 10 will be described with reference to FIGS. 2 and 3. FIG.
As described above, inside the plate member 10, the gas flow path 60 is formed to allow the gas outflow hole 61 and the gas inflow hole 62 to communicate with each other. As shown in FIG. 2 and the like, the gas channel 60 according to this embodiment includes a plane-parallel gas channel 60T, a plurality of gas outflow channels 60V1, and a gas inflow channel 60V2. The plane-parallel gas flow channel 60T is a tunnel-shaped gas flow channel portion extending in the horizontal direction, that is, parallel to the first surface S1. The gas outflow path 60V1 extends vertically, that is, perpendicular to the first surface S1, and is connected to a first connection hole 63 provided in the upper wall surface of the plane-parallel gas flow path 60T. It is a gas channel portion that communicates with the parallel gas channel 60T. The gas inflow path 60V2 extends in the vertical direction, that is, perpendicular to the first surface S1, is connected to a second connection hole 64 provided in the lower wall surface of the plane-parallel gas flow path 60T, and is plane-parallel to the gas inflow hole 62. It is a gas channel portion that communicates with the gas channel 60T. In the present embodiment, the first connection hole 63 and the second connection hole 64 are provided at positions that do not overlap each other when viewed from the normal direction of the first surface S1. Although the shapes of the gas outflow hole 61 and the gas inflow hole 62 and the cross-sectional shape of the gas flow path 60 are not limited, the present embodiment exemplifies the case where they are all formed in a substantially circular shape.

As shown in FIG. 2, inside the plate member 10, the first electrode 51 is arranged above the plane-parallel gas flow passage 60T, that is, on the first surface S1 side, and below the plane-parallel gas flow passage 60T, that is, on the first surface S1 side. A second electrode 52 is arranged on the second surface S2 side. Thus, the plane-parallel gas flow path 60T is sandwiched between the first electrode 51 and the second electrode 52 from above and below. The first electrode 51 and the second electrode 52 are made of a conductive material containing tungsten, molybdenum, or the like, for example. In the present embodiment, the first electrode 51 has a planar shape substantially parallel to the first surface S1 and functions as a chuck electrode that develops electrostatic attraction for attracting the wafer W or the like onto the first surface S1. For example. In this case, the first electrode 51 is connected to a power supply via a terminal or the like, and power is supplied to the first electrode 51 as necessary, thereby attracting and holding the wafer W on the first surface S1. In this embodiment, the second electrode 52 is also assumed to have a planar shape substantially parallel to the first surface S1.

As shown in FIGS. 2 and 3, the planar first electrode 51 has a first connection hole at a position directly above the first connection hole 63 of the plane-parallel gas flow path 60T located below. A first through hole 51H that is one size larger than 63 is provided, and the gas outflow path 60V1 is inserted through the center of the first through hole 51H. As shown in FIG. 3, the hole edge of the first through hole 51H is separated from the wall surface of the gas outflow path 60V1 by a predetermined distance D1. In other words, the first electrode 51 is provided with a predetermined distance D1 from the wall surface of the gas outflow path 60V1. Similarly, as shown in FIGS. 2 and 3, the planar second electrode 52 is provided with a second electrode 52 at a position directly below the second connection hole 64 of the plane-parallel gas flow path 60T located above. A second through hole 52H that is slightly larger than the connection hole 64 is provided, and the gas inflow path 60V2 is inserted through the center of the second through hole 52H. That is, as shown in FIG. 3, the second electrode 52 is provided with a predetermined distance D2 from the wall surface of the gas inflow passage 60V2. If the first electrode 51 and the second electrode 52 made of a conductive material are exposed or close to the gas outflow path 60V1 or the gas inflow path 60V2, they become objects of discharge when high-frequency power is applied. This is because the first electrode 51 or the second electrode 52 and the walls of the gas outflow path 60V1 or the gas inflow path 60V2 need to be separated by a constant distance. The distance D1 and the distance D2 may be the same size or different from each other, depending on the forming material of the first electrode 51, the second electrode 52, the plate member 10, the assumed plasma processing conditions, and the like. Can be set.

As shown in FIG. 2 , a porous body 70 is arranged inside the gas flow path 60 formed in the plate member 10 . The porous body 70 is formed so as to allow a fluid such as a thermally conductive gas to flow through the inside of the gas flow path 60 and eliminate large voids that extend linearly in the vertical direction. As shown in FIG. 3, in the holding device 100 according to the present embodiment, a first porous body 71 is arranged as the porous body 70 in the region extending from the inside of the gas outlet channel 60V1 to the inside of the plane-parallel gas channel 60T. and a second porous body 72 arranged in a region extending from the inside of the gas inflow passage 60V2 to the inside of the plane-parallel gas passage 60T.

As shown in FIG. 3, the porous body 70 has an inflow/outflow channel internal porous body portion 70V and a parallel channel internal porous body portion 71T. Specifically, the first porous body 71 and the second porous body 72 respectively include the inflow/inflow path inner porous body portions 71V and 72V located inside the gas outflow path 60V1 or the gas inflow path 60V2, and the plane-parallel gas flow paths. It has parallel flow channel inner porous body portions 71T and 72T located within 60T. In the present embodiment, the inflow/outflow path internal porous body portion 70V and the parallel flow path internal porous body portion 70T are integrally formed in each porous body 70 . More specifically, in the first porous body 71, a portion continuing from the inflow/outflow channel internal porous body portion 71V protrudes from the first connection hole 63 into the plane-parallel gas channel 60T, thereby forming a parallel channel internal porous body. A portion 71T is formed. Similarly, in the second porous body 72, a portion continuing from the inflow/outflow channel internal porous body portion 72V protrudes from the second connection hole 64 into the plane-parallel gas channel 60T, thereby forming a parallel channel internal porous body portion. 72T is formed. As shown in FIG. 3, the intra-parallel flow path porous body portions 71T and 72T are arranged in the first through hole 51H of the first electrode 51 or the second through hole 52 of the second electrode 52 when viewed from the normal direction of the first surface S1. It is formed so as to overlap the entire surface of the hole 52H. In addition, as shown in FIG. 3, in the present embodiment, in the plane-parallel gas flow path 60T, when viewed from the normal direction of the first surface S1, a , an empty region ER in which the porous body 70 is not arranged is left.

The holding device 100 according to the present embodiment as described above is formed by joining the separately produced plate-like member 10 to the base member 20 produced by a known method via the joining material 30 as shown in FIG. 1 and the like. and can be manufactured. The method of manufacturing the plate-like member 10 having the porous bodies 70 disposed thereon is not particularly limited, and various known methods can be appropriately adopted. For example, after manufacturing a ceramic substrate provided with electrodes including the first electrode 51 and the second electrode 52 and gas flow paths 60 by a known method, a fluid porous body precursor having an appropriate viscosity is added to the gas outlet holes. 61 or the gas inflow hole 62 into the gas outflow path 60V1 or the gas inflow path 60V2. After injecting the porous body precursor so that a predetermined amount protrudes into the plane-parallel gas flow path 60T from the first connection hole 63 or the second connection hole 64, the porous body precursor is cured by heating or the like, thereby achieving the above-described mode. , the first porous body 71 and the second porous body 72 can be arranged in the gas flow path 60 . Alternatively, a plurality of green sheets are each formed with grooves and holes that constitute the gas flow paths 60, and the porous body precursor or the porous body 70 is arranged in an appropriate position and stacked and fired to form a plate. A shaped member 10 may be fabricated. Alternatively, block bodies are produced by dividing a ceramic substrate into a plurality of pieces, and after arranging prefabricated porous bodies 70 in suitable positions of grooves and holes constituting gas flow paths 60 in each block body, the block bodies are joined together. The plate member 10 may be produced by joining.

The holding apparatus 100 as described above is used, for example, as part of a semiconductor manufacturing apparatus. The holding device 100 is installed in the chamber of the semiconductor manufacturing apparatus, and the wafer W is placed on the first surface S1 of the plate member 10 . When power is supplied to the first electrode 51 functioning as a chuck electrode, electrostatic attraction is generated and the wafer W is attracted to the first surface S1. Further, when the raw material gas is introduced into the chamber and high-frequency power is applied to the base member 20, plasma is generated and a bias voltage is generated on the wafer W to perform processing.

When the wafer W is processed, the wafer W is cooled through the plate-shaped member 10 when the coolant flows through the coolant passage 21 of the base member 20 . When the temperature of the wafer W is adjusted in this way, the thermally conductive gas injected from the gas injection passage 23 of the base member 20 into the gas passage 60 of the plate-like member 10 flows into the gas outflow holes 61 of the first surface S1. and fills the gap G formed between the first surface S1 and the wafer W, thereby controlling the temperature of the wafer W with high accuracy.

When the wafer W is processed, high-frequency power is applied to the base member 20 as described above. may occur. Particularly in recent years, high-frequency power applied during plasma processing has been increased in voltage in order to speed up processing, etc., and the potential difference between the wafer W and the base member 20 has increased, causing abnormalities in the gas flow path 60. Discharge is likely to occur.

FIG. 4 is a cross section schematically showing the outline of the internal structure including the gas flow path 60 of the plate member 110 according to the reference example. In the plate-shaped member 110 according to the reference example, the first porous body 171 and the second porous body 172 arranged in the gas flow path 60 do not have a parallel flow path inner porous body portion. It is different from the plate member 10 concerned. Since other configurations are basically the same as those of the plate-like member 10, the same reference numerals as those of the plate-like member 10 are used, and description thereof is omitted.

In the plate member 110 shown in FIG. 4, the first porous body 171 or the second porous body 172 is arranged inside the gas outflow path 60V1 and the gas inflow path 60V2 of the gas flow path 60. As shown in FIG. Therefore, the occurrence of abnormal discharge in the gas outflow path 60V1 and the gas inflow path 60V2 is reduced. In addition, most of the plane-parallel gas flow path 60T is sandwiched between the first electrode 51 and the second electrode 52 arranged above and below, and abnormal discharge does not occur in the area sandwiched between these electrodes. reduced. However, in order to avoid abnormal discharge in the gas outflow path 60V1 and the gas inflow path 60V2, the first electrode 51 is spaced from the wall surface of the gas outflow path 60V1 by a distance D1, and the second electrode 52 is spaced from the gas inflow path 60V2 wall surface by a distance D2. are spaced apart from each other. Therefore, a region LR (see FIG. 4 There is a shaded area in . Discharge countermeasures are insufficient in this region LR, and abnormal discharge is likely to occur.

In contrast to the plate-like member 110 shown in FIG. 4, in the plate-like member 10 according to the present embodiment shown in FIG. A parallel flow path inner portion 71T of the first porous body 71 and a parallel flow path inner portion 72T of the second porous body 72 are arranged in the portion where there is no parallel flow path. As a result, even in the area corresponding to the area LR in FIG. 4, the occurrence of abnormal discharge during processing of the wafer W is reduced.

(Effect of this embodiment)
As described above, the holding device 100 according to the present embodiment has the first surface S1 for holding the object (wafer) W and the second surface S2 located on the opposite side of the first surface S1. An insulating plate-like member 10 is provided, and inside the plate-like member 10, there are a gas flow channel 60, which is a plane-parallel gas flow channel 60T extending parallel to the first surface S1, and the plane-parallel gas flow a gas outflow path 60V1 connected to a first connection hole 63 provided in the wall surface of the path 60T to allow communication between the gas outflow hole 61 provided in the first surface S1 and the plane-parallel gas flow path 60T; A gas inflow passage that is connected to a second connection hole 64 provided in the wall surface of the plane-parallel gas passage 60T and communicates the gas inflow hole 62 provided in the second surface S2 with the plane-parallel gas passage 60T. 60V2, a first electrode 51 disposed between the first surface S1 and the plane-parallel gas flow channel 60T, the second surface S2 and the plane-parallel gas flow channel 60T. and a second electrode 52 disposed between the first electrode 51 and the wall surface of the gas outflow path 60V1 with a predetermined gap D1 between the first electrode 51 and the wall surface of the gas outlet passage 60V1. A first through hole 51H through which the gas outflow path 60V1 is inserted is formed. A second through hole 52H through which the inflow path 60V2 is inserted is formed, and an insulating porous body 70 is disposed inside the gas flow path 60. The porous body 70 is the gas outflow path 60V1 or the The inflow/outflow path inner porous body portion 70V disposed inside at least one of the gas inflow paths 60V2 overlaps the first through hole 51H or the second through hole 52H when viewed from the normal direction of the first surface S1. and an intra-parallel flow path porous body portion 70T disposed inside the plane-parallel gas flow path 60T.

According to the above configuration, the occurrence of abnormal discharge inside the gas outflow path 60V1 or the gas inflow path 60V2 is reduced by the inflow/outflow path inner porous body portion 70V. Occurrence of abnormal discharge is reduced by the parallel flow path inner porous body portion 70T even in the region LR in which the electrodes cannot be arranged above and below in order to ensure the insulation of the electrodes in the plane-parallel gas flow path 60T. be. As a result, in the plane-parallel gas flow path 60T, the porous body 70 is arranged inside in the vicinity of the first connection hole 63 and the second connection hole 64, and the first electrode 51 and the second electrode are arranged vertically in other regions. 52 are arranged to reduce the occurrence of abnormal discharge over the entire plane-parallel gas flow path 60T. As a result, it is possible to take measures against abnormal discharge for the entire gas flow path 60 formed inside the plate member 10, and it is possible to provide the holding device 100 in which the occurrence of abnormal discharge is reduced. In the above description, it is preferable that the parallel flow path internal porous body portion 70T is arranged so as to overlap the entire area of the first through hole 51H or the second through hole 52H when viewed from the normal direction of the first surface S1.
In addition, the gas channels are provided with a plurality of plane-parallel gas channels inside the plate-like member, and the plurality of gas channels (including the gas outlet channel and the gas inlet channel) extending in a direction intersecting the first surface, The gas inflow hole and the gas outflow hole may be configured to communicate with each other via a plurality of plane-parallel gas flow paths.

Further, in the holding device 100 according to the present embodiment, the plane-parallel gas flow path 60T is provided with an empty region ER in which the porous body 70 is not arranged.

Disposing the porous body 70 over the entire interior of the gas flow path 60 can suppress the occurrence of abnormal discharge, but inevitably reduces the flow rate of the gas. According to the above configuration, the first electrode 51 and the second electrode 52 are arranged while the porous body 70 is arranged in the region LR where it is difficult to arrange the electrodes vertically in the plane-parallel gas flow passage 60T. Therefore, the porous body 70 can be formed so as not to be arranged in a region where measures against abnormal discharge are possible. As a result, it is possible to reduce the occurrence of abnormal discharge while minimizing the decrease in gas flow rate.

Further, in the holding device 100 according to the present embodiment, the first connection hole 63 and the second connection hole 64 are provided at positions that do not overlap each other when viewed from the normal direction of the first surface S1.

During plasma processing, high-frequency power is applied in a direction from the second surface S2 toward the first surface S1, that is, generally along the normal direction of the first surface S1. Since the gas flow path 60 has a higher porosity than other portions of the plate-like member 10 even if the porous body 70 is arranged inside, the gas flow path 60 is formed so as to line up along the normal direction. 60, especially in the gas flow path 60 formed inside the plate member 10 so as to linearly penetrate from the side of the first surface S1 to the side of the second surface S2, there is a high possibility that abnormal discharge will occur. According to the above configuration, the first connection hole 63 and the second connection hole 64 are formed at mutually shifted positions when viewed from the normal direction of the first surface S1, and the gas outflow path 60V1 and the gas inflow path 60V2 are formed at mutually shifted positions. are not aligned vertically. Therefore, the possibility of abnormal discharge occurring inside the gas outflow path 60V1 and the gas inflow path 60V2 is reduced compared to the case where these are formed at positions overlapping each other in the vertical direction.

Further, in the holding device 100 according to the present embodiment, the porous body 70 is arranged from the inside of the gas outflow path 60V1 so as to overlap the first through hole 51H when viewed from the normal direction of the first surface S1. The first porous body 71 disposed in the region extending to the inside of the plane-parallel gas flow path 60T and the second through-hole 52H are overlapped as viewed from the normal direction of the first surface S1. and a second porous body 72 arranged in a region extending from the inside of the gas inlet channel 60V2 to the inside of the plane-parallel gas channel 60T.

According to the above configuration, the first porous body extends from the gas outflow path 60V1 to the plane-parallel gas flow path 60T in the vicinity of the first connection hole 63, and from the gas inflow path 60V2 to the plane-parallel gas flow path 60T in the vicinity of the second connection hole 64. A second porous body 72 is arranged in each of the . Therefore, the occurrence of abnormal discharge is further reduced as compared with a configuration in which only one of the porous bodies 70 is provided.

In addition, in the holding device 100 according to the present embodiment, the parallel flow path inner porous body portions 71T and 72T are configured such that a part of the porous body 70 connected to the inflow/outflow path inner porous body portions 71V and 72V is the first It is formed by protruding from the connection hole 63 or the second connection hole 64 into the plane-parallel gas flow path 60T.

According to the above configuration, the inflow/inflow channel internal porous body portions 71V and 72V and the parallel channel internal porous body portions 71T and 72T are integrally formed, and the porous bodies 71 and 72 have a shape having a bent portion. Therefore, the porous bodies 71 and 72 are less likely to be displaced within the gas flow path 60, and the generation of particles due to friction or the like can be reduced while stably obtaining the effect of suppressing abnormal discharge. Further, for example, a fluid precursor for forming the porous body 70 is injected from the gas outflow path 60V1 or the gas inflow path 60V2 so as to protrude into the plane-parallel gas flow path 60T, and hardened. It is possible to easily form the in-incoming porous body portions 71V and 72V and the in-parallel flow channel porous body portions 71T and 72T and arrange them in the gas flow channel 60 .

<Other embodiments>
(1) In the above embodiment, an example in which the inflow/outflow path internal porous body portion and the parallel flow path internal porous body portion are integrally formed has been described, but the present invention is not limited to this. For example, like the plate-like member 210 shown in FIG. It doesn't matter if

(2) In the above embodiment, a heater electrode made of a heating resistor and connected to a power source via a terminal or the like is provided inside the plate member 10 in addition to the first electrode 51 and the second electrode 52 . may have been By supplying power to the heater electrode as necessary, the plate-like member 10 is heated, and the wafer W held on the first surface S1 of the plate-like member 10 is heated. The temperature of the wafer W can be controlled by adjusting the power supply to the heater electrode. Further, in the above embodiment, the case where the first electrode 51 functions as a chuck electrode was exemplified, but the present invention is not limited to this. The chuck electrode may be provided separately from the first electrode 51 .

(3) The first electrode and the second electrode may or may not be electrically connected to other electrodes or terminals. Even if electric power is not supplied to both electrodes, abnormal discharge in the plane-parallel gas flow path can be reduced by increasing the capacitance. Also, the first electrode and the second electrode may or may not be electrically connected to each other. By electrically connecting both electrodes, the potential difference in the plane-parallel gas flow path disposed between them is reduced, and the occurrence of abnormal discharge can be further reduced.

(4) In the above embodiment, the example in which the porous bodies 70 are arranged in all of the plurality of gas outflow paths 60V1 and the gas inflow paths 60V2 is shown, but the present invention is not limited to this. Even by arranging a porous body according to the present disclosure in a part of a plurality of gas inflow and outflow paths, the occurrence of abnormal discharge in the gas flow path is reduced compared to a holding device without such a porous body. can.

(5) The base member is not limited to one in which the gas injection path is formed. For example, a groove extending from the gas inlet hole 62 to the outer periphery is formed on the second surface S2 of the plate-like member 10, and the heat-conducting gas is injected from this groove and introduced into the gas flow path 60. may have been Also, the base member is not limited to one in which the refrigerant passage is formed. It is preferable that the base member is made of a material with high thermal conductivity, or has some kind of cooling mechanism such as cooling fins.

(6) The material forming each member in the holding device of the above embodiment is merely an example, and each member may be formed of another material. Moreover, the manufacturing method of the holding device and the like in the above embodiment is merely an example, and various modifications are possible.

(7) The present disclosure is not limited to the electrostatic chuck exemplified in the above embodiment, and can be similarly applied to other holding devices (for example, heating devices, etc.) that hold an object on the surface of a ceramic substrate. be.

DESCRIPTION OF SYMBOLS 100... Holding|maintenance apparatus 10, 110, 210... Plate-shaped member 20... Base member 21... Coolant path 23... Gas injection path 30... Joining material 51... First electrode 51H... First through-hole 52... Second electrode 52H... Second Through hole 60 Gas channel 60T Plane parallel gas channel 60V1 Gas outflow channel 60V2 Gas outflow channel 61 Gas outflow hole 62 Gas inflow hole 63 First connection hole 64 Second connection hole 70 Porous body 71, 171, 271... First porous bodies 72, 172... Second porous bodies 70T, 71T, 72T, 271T... Porous body parts in parallel flow paths 70V, 71V, 72V, 171V, 271V... Porous body parts in inflow and outflow paths S1 First surface S2 Second surface G Gap D1 Spacing (between the first electrode and the wall surface of the gas outflow channel) D2 Spacing (between the second electrode and the wall surface of the gas inflow channel) ER Empty region LR ( Region W: Wafer (target)

Claims (5)

An insulating plate-shaped member having a first surface for holding an object and a second surface located on the opposite side of the first surface,
Inside the plate member,
a gas flow path,
a plane-parallel gas flow path extending parallel to the first surface;
a gas outflow path that is connected to a first connection hole provided in a wall surface of the plane-parallel gas flow path so as to allow communication between the gas outflow hole provided on the first surface and the plane-parallel gas flow path;
a gas inflow path connected to a second connection hole provided in a wall surface of the plane-parallel gas flow path to allow communication between the gas inflow hole provided in the second surface and the plane-parallel gas flow path. a gas flow path;
a first electrode disposed between the first surface and the plane-parallel gas flow path;
a second electrode interposed between the second surface and the plane-parallel gas flow path;
The first electrode is formed with a first through hole through which the gas outflow path is inserted with a predetermined gap between the first electrode and the wall surface of the gas outflow path,
The second electrode is formed with a second through hole through which the gas inflow path is inserted with a predetermined gap between the second electrode and the wall surface of the gas inflow path,
An insulating porous body is arranged inside the gas channel,
The porous body is
an inflow/outflow channel internal porous body portion disposed inside at least one of the gas outflow channel and the gas inflow channel;
an intra-parallel flow path porous body portion arranged inside the plane-parallel gas flow path so as to overlap with the first through-hole or the second through-hole when viewed from the normal direction of the first surface; holding device. 2. The holding device according to claim 1, wherein said plane-parallel gas flow path is provided with an empty region where said porous body is not disposed. The holding device according to claim 1 or 2, wherein said first connection hole and said second connection hole are provided at positions not overlapping with each other when viewed from the normal direction of said first surface. The porous body is
a first porous body arranged in a region extending from the inside of the gas outlet channel to the inside of the plane-parallel gas channel so as to overlap with the first through hole when viewed from the normal direction of the first surface;
A second porous body arranged in a region extending from the inside of the gas inlet channel to the inside of the plane-parallel gas channel so as to overlap the entire second through hole when viewed from the normal direction of the first surface. 4. A retaining device according to any one of claims 1 to 3, comprising: A part of the porous body connected to the inflow/outflow path internal porous body portion protrudes from the first connection hole or the second connection hole into the plane-parallel gas flow path. 5. A retaining device according to any one of the preceding claims, formed by:

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