JP7329997B2 - Electrostatic chuck device - Google Patents

Description

The present invention relates to an electrostatic chuck device.

2. Description of the Related Art In a semiconductor manufacturing apparatus, an electrostatic chuck is known that holds and attracts a substrate such as a semiconductor wafer by electrostatic force in order to perform various processes such as measurement, transportation, and processing on the substrate. In such an electrostatic chuck, it is necessary to hold a substrate that is deformed such as bending or warping in a state of being flattened by attracting the substrate.

In addition, in Patent Document 1, a second substrate having a through hole extending in the thickness direction is placed on the first substrate, and the substrate placed on the second substrate has the through hole. It is disclosed that the flatness of the substrate is corrected by sucking the substrate from the portion that abuts on the projection formed on the upper surface of the second substrate due to the pressure reduction through the second substrate.

Further, Japanese Patent Laid-Open No. 2002-200002 discloses correcting distortion of a frame in a dry etching apparatus by pressing a frame of a transport carrier placed on a stage against the stage with a correcting member. The correction member is preferably made of an elastic material, and corrects distortion of the frame by descending and pressing the frame.

JP 2017-118105 A JP 2016-51877 A

However, the technology described in Patent Literature 1 cannot be applied to the decompression process. Further, referring to the technique described in Patent Document 2, when it is assumed that the distortion of a substrate that is attracted by an electrostatic chuck is corrected, the upper surface of the substrate on which devices are formed is contaminated by the contact of the correcting member. There is a risk.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and provides an electrostatic chuck device capable of flattening a substrate, which is applicable even in a decompression process, while suppressing the risk of contamination of the upper surface of the substrate. intended to provide

The present invention is an electrostatic chuck device comprising an electrostatic chuck having a substrate mounting surface on which a substrate is mounted, and a correction device for correcting the shape of the substrate mounted on the substrate mounting surface. wherein the correction device comprises a jig, a first drive mechanism for driving the jig in a first specified direction, and a second drive mechanism for driving the jig in a second specified direction, a guide surface extending in a direction inclined with respect to the substrate mounting surface and positioned above the outer peripheral portion of the substrate in a driving process in the first designated direction by the first drive mechanism; and a guide surface that brings the outer peripheral portion of the substrate closer to the substrate mounting surface while contacting the outer peripheral portion of the substrate in the subsequent driving process in the second designated direction by the second driving mechanism. Characterized by

According to the present invention, the guide surface of the jig is positioned above the outer peripheral portion of the substrate in the process of driving in the first specified direction, and is positioned above the outer peripheral portion of the substrate in the subsequent process of driving in the second specified direction. The peripheral portion of the substrate is brought closer to the substrate mounting surface while being in contact with the substrate. Therefore, without contacting the upper surface of the substrate with other members, the outer peripheral portion of the substrate is brought closer to the substrate mounting surface and is attracted by the electrostatic force, so that flatness correction can be performed. It is possible to suppress the risk of contamination. Furthermore, since this correction does not involve decompression unlike the technique disclosed in Patent Document 1, it can also be applied in decompression processes.

In the present invention, for example, the jig has a shaft portion extending in a direction perpendicular to the substrate mounting surface, and a claw portion protruding from a portion of the shaft portion in the circumferential direction and having the guide surface. , the first designated direction is a direction around the axis of the shaft portion positioned outside the substrate mounting surface, and the second designated direction is a downward direction perpendicular to the substrate mounting surface. be.

In this case, the jig is driven in a direction around the axis of the shaft portion and is moved downward in a direction perpendicular to the substrate mounting surface, so that the guide surface contacts the outer circumference of the substrate while the jig is in contact with the outer circumference of the substrate. It becomes possible to bring the part closer to the substrate mounting surface.

Further, in the present invention, for example, the jig has a shaft portion extending in a direction perpendicular to the substrate mounting surface, and a spiral groove formed on an outer peripheral surface of the shaft portion, defining the groove. At least a part of the wall surface of the shaft portion forming the guide surface, the first specified direction is a direction around the axis of the shaft portion positioned outside the substrate mounting surface, and the second The specified direction is a downward direction in a direction perpendicular to the substrate mounting surface.

In this case, the jig is driven in a direction around the axis of the shaft portion and moved downward in a direction perpendicular to the substrate mounting surface, so that the surface of the spiral groove comes into contact with the outer peripheral portion of the substrate. It is possible to bring the outer peripheral portion of the substrate close to the substrate mounting surface.

Further, in the present invention, for example, the first specified direction is parallel to the substrate mounting surface and extends from the outside to the inside of the substrate mounting surface, and the second specified direction is the substrate mounting surface. This is the downward direction in the direction perpendicular to the mounting surface.

In this case, the jig is parallel to the substrate mounting surface, driven in a direction from the outside to the inside of the substrate mounting surface, and moved downward in a direction perpendicular to the substrate mounting surface. It is possible to bring the outer peripheral portion of the substrate closer to the substrate mounting surface while the surface is in contact with the outer peripheral portion of the substrate.

1 is a schematic top view showing an electrostatic chuck device according to a first embodiment of the present invention; FIG. FIG. 2 is a schematic cross-sectional view taken along line II-II of FIG. 1; FIG. 4 is a schematic partial enlarged cross-sectional view showing a state in which the jig is lifted; FIG. 4 is a schematic partial enlarged cross-sectional view showing a state in which the outer peripheral edge of the substrate is in contact with the guide surface; FIG. 3 is a schematic partial enlarged cross-sectional view showing a state in which a substrate is flatly held on a substrate mounting surface; FIG. 5 is a schematic cross-sectional view showing an electrostatic chuck device according to a second embodiment of the present invention; FIG. 4 is a schematic partial enlarged cross-sectional view showing a state in which the jig is lifted; FIG. 3 is a schematic partial enlarged cross-sectional view showing a state in which a substrate is flatly held on a substrate mounting surface; FIG. 2 is a schematic partial enlarged cross-sectional view showing a jig included in the electrostatic chuck device according to the first embodiment of the present invention;

An electrostatic chuck device 100 according to a first embodiment of the present invention will be described with reference to the drawings. In the drawings, the electrostatic chuck device 100 and its constituent elements are deformed for clarity, and the directions such as up and down are merely examples and do not represent actual ratios.

1 and 2, an electrostatic chuck device 100 includes an electrostatic chuck 10 that attracts and holds a substrate W such as a semiconductor wafer, and a corrector that corrects the shape of the substrate W attracted and held by the electrostatic chuck 10 . a device 20;

The electrostatic chuck 10 is not particularly limited as long as it has a known configuration. The electrostatic chuck 10 includes a substrate 11 made of, for example, a ceramic sintered body, an electrostatic attraction electrode 12 embedded in the substrate 11, and a power supply terminal 13 for supplying power to the electrode 12. , and a current supply member 14 embedded in the substrate 11 for electrically connecting the electrode 12 and the terminal 13 . Although not shown, the terminal 13 is configured so that power can be supplied from an external power source.

The base 11 has a substrate mounting surface 11a on which the substrate W is mounted as an upper surface. The substrate mounting surface 11a may be a wide planar surface or may be formed by a group of flat tip surfaces of a plurality of projections. The group of flat tip surfaces of the plurality of protrusions is, for example, a group of flat tip surfaces of a large number of pins (protrusions) or the tip surfaces of a plurality of annular ribs (protrusions). good too.

A channel member having an outer shape larger than that of the base 11 and having a channel formed therein may be joined to the lower surface of the base 11 . In this case, a through-hole may be provided through the channel member in a direction perpendicular to the substrate mounting surface 11a, and a jig 21, which will be described later, can protrude through the through-hole.

The correction apparatus 20 includes a jig 21, a first driving mechanism 22 that drives the jig 21 in a first designated direction W1, and a second driving mechanism 22 that drives the jig 21 in a second designated direction W2 different from the first designated direction W1. 2 drive mechanism 23 .

In this embodiment, the jig 21 includes a shaft portion 24 positioned outside the substrate mounting surface 11a and extending in the vertical direction perpendicular to the substrate mounting surface 11a, and a portion of the shaft portion 24 in the circumferential direction. and a claw portion 25 protruding at the . The claw portion 25 has a guide surface 25a extending in a direction inclined with respect to the substrate mounting surface 11a, that is, in a direction inclined other than the horizontal direction.
In this embodiment, the first specified direction W1 is the direction around the axis of the shaft portion 24, and the second specified direction W2 is the downward direction perpendicular to the substrate mounting surface 11a.

In this embodiment, the jigs 21 are composed of a plurality of pieces and arranged symmetrically with respect to the substrate mounting surface 11a. However, the number of jigs 21 may be one, and the jigs 21 may not necessarily be arranged symmetrically with respect to the substrate mounting surface 11a.

Specifically, the jig 21 has a columnar shaft portion 24 and a claw portion 25 that protrudes partially in the circumferential direction from the upper portion of the shaft portion 24. The claw portion 25 is inclined downward. It has a planar guide surface 25a. Here, the portion above the guide surface 25a extends from the upper end portion of the guide surface 25a and protrudes so as to extend upward. It is also possible that there is no portion above from. Further, the guide surface 25a is not limited to a flat surface. may

Although not shown, the first drive mechanism 22 is, for example, a motor or the like that rotationally drives a disc-shaped gear portion that meshes with a gear portion that is continuously formed in the circumferential direction and that is formed at the lower portion of the shaft portion 24 . 1 drive section and a first control section for controlling the first drive section. Thereby, the first drive mechanism 22 can rotate each jig 21 in both the first specified direction W1 and the opposite direction, that is, in both directions around the axis of the shaft portion 24 .

The second drive mechanism 23 includes, for example, a motor (not shown) that rotates a disk-shaped gear portion that meshes with a continuous gear portion that is continuously formed in the lower portion of the shaft portion 24 in the axial direction. and a second control section for controlling the second drive section. Thereby, the second drive mechanism 23 can move each jig 21 in the second specified direction W2 and its opposite direction, that is, both up and down directions. It should be noted that a plurality of jigs 21 may be configured to be driven simultaneously by common drive mechanisms 22 and 23 .

A method for holding the substrate W using the electrostatic chuck device 100 according to the first embodiment will be described below.

First, referring to FIG. 2, the substrate W is placed on the substrate placement surface 11a of the electrostatic chuck 10. As shown in FIG. The substrate W is bent so that its center portion is convex downward, and is in contact with the portion of the substrate mounting surface 11a near the center. The gap in the vertical direction is large. At this time, the guide surface 25a of the jig 21 is located below the substrate W, and the claw portion 23 is located on the side opposite to the substrate W. As shown in FIG.

Next, referring to FIG. 3A, the second drive mechanism 23 is driven to move the jig 21 upward until the guide surface 25a is positioned above the outer peripheral portion of the substrate W. Then, referring to FIG.

Next, referring to FIG. 3B, the first drive mechanism 22 is driven so that the claw portion 25 faces the substrate W side, that is, the guide surface 25a is positioned above the outer peripheral portion of the substrate W. The jig 21 is rotated around the axis of the shaft portion 24 . This step corresponds to the drive process by the first drive mechanism of the present invention.

Next, referring to FIG. 3C, the second driving mechanism 23 is driven to bring the guide surface 25a into contact with the outer peripheral portion of the substrate W, and further, while maintaining this contact, the guide surface 25a moves the outer peripheral portion of the substrate W. moves downward to approach the substrate mounting surface 11a. This step corresponds to the driving process by the second driving mechanism of the present invention. As a result, the bending of the substrate W is gradually eliminated. As this deflection is eliminated, the portion of the substrate W that abuts against the guide surface 25a sequentially moves outward in the circumferential direction, but since the guide surface 25a is inclined, such movement is possible.

Next, when the substrate W is flatly placed on the substrate placement surface 11a without bending, the second driving mechanism 23 is stopped, and the jig 21 is moved downward. stop moving.

By supplying electric power to the electrode 12, the substrate W is attracted and held on the substrate mounting surface 11a by electrostatic force. It should be noted that the supply of electric power to the electrode 12 may be started before the substrate W is flatly mounted, and the substrate W may be attracted to the substrate mounting surface 11a by electrostatic force.

Next, by driving the first driving mechanism 22, the jig is moved so that the claw portion 25 faces the opposite side of the substrate W, that is, so that the contact between the guide surface 25a and the outer peripheral portion of the substrate W is released. Rotate 21.

Finally, the second drive mechanism 23 is driven to move the jig 21 downward and return the jig 21 to its initial state. Even if the contact between the substrate W and the jig 21 is released, the substrate W can be held in a flat state because an electrostatic force is acting against the restoring force that restores the bending. .

As described above, since the bending of the substrate W is eliminated by driving the jig 21, unlike the technique disclosed in the above-mentioned Patent Document 1, it is possible to apply the technique also to the decompression process. Furthermore, since the guide surface 25a of the jig 21 only abuts against the outer peripheral portion of the substrate W and the jig 21 does not contact the upper surface of the substrate W, the upper surface of the substrate W on which devices are formed is not contaminated. It is possible to suppress the risk of

3A to 3C, the outer peripheral end surface of the substrate W is wholly or partially rounded, so particles and the like are generated even if it comes into contact with the guide surface 25a of the jig 20. Not likely. Further, the outer peripheral portion of the substrate W that contacts the guide surface 25a is not limited to the outer peripheral end surface of the substrate W, and may include the upper or lower surface of the substrate W near the outer peripheral end surface.

An electrostatic chuck device 200 according to a second embodiment of the present invention will be described below with reference to the drawings.

Referring to FIG. 4 , electrostatic chuck device 200 includes electrostatic chuck 10 described above and correction device 120 that corrects the shape of substrate W attracted and held by electrostatic chuck 10 .

The correction device 120 includes a jig 121, a first drive mechanism 122 that drives the jig 121 in a first specified direction W1, and a second drive mechanism 122 that drives the jig 121 in a second specified direction W2 different from the first specified direction. A driving mechanism 123 is provided.

In this embodiment, the jig 121 is positioned outside the substrate mounting surface 11a and is formed on the shaft portion 124a extending in the vertical direction perpendicular to the substrate mounting surface 11a and the outer peripheral surface of the shaft portion 124a. It has a threaded portion 124 with a helical groove 124b. The pitch of the spiral is equal to or greater than the thickness of the substrate W. FIG. In this embodiment, the first specified direction W1 is the direction around the axis of the shaft portion 124a, and the second specified direction W2 is the downward direction perpendicular to the substrate mounting surface 11a.

In addition, in this embodiment, the jigs 121 are composed of a plurality of pieces and arranged symmetrically with respect to the substrate mounting surface 11a. However, the number of jigs 121 may be one, and the jigs 121 may not necessarily be arranged symmetrically with respect to the substrate mounting surface 11a.

The first drive mechanism 122 rotates a disk-shaped gear portion (not shown) that meshes with a gear portion continuously formed in a circumferential direction formed in a portion 125 below the threaded portion 124, for example. It is composed of a first drive section such as a motor and a first control section that controls the first drive section. Thereby, the first drive mechanism 122 can rotate each jig 121 in both the first specified direction W1 and the opposite direction, that is, in both directions around the axis of the shaft portion 124a.

Although not shown, the second drive mechanism 123 is, for example, a motor or the like that rotationally drives a disk-shaped gear portion that meshes with a continuous gear portion that is axially continuously formed on the lower portion 125 . It is composed of two drive sections and a second control section that controls the second drive section. Thereby, the second drive mechanism 123 can move each jig 121 in the second specified direction W2 and its opposite direction, that is, both up and down directions. It should be noted that a plurality of jigs 121 may be configured to be driven simultaneously by common drive mechanisms 122 and 123 .

A method for attracting and holding the substrate W using the electrostatic chuck device 200 according to the second embodiment will be described below.

First, referring to FIG. 4 , a substrate W is placed on the substrate placement surface 11 a of the electrostatic chuck 10 . The substrate W is bent so that its center portion is convex downward, and is in contact with the portion near the center of the substrate mounting surface 11a. The gap in the vertical direction is large. At this time, the jig 121 is positioned below the substrate W. As shown in FIG.

Next, referring to FIG. 5A, while the second drive mechanism 123 is driven to move the jig 121 upward, the first drive mechanism 122 is driven to rotate the jig 121 about the axis. As a result, the jig 121 spirally moves upward. At this time, the outer peripheral portion of the substrate W contacts the surface of the groove 124b, but basically the height position of the outer peripheral portion of the substrate W is maintained.

Next, the driving of the first driving section 122 and the second driving section 123 is stopped. At this time, the outer peripheral portion of the substrate W is in contact with the wall surface of the shaft portion 124a defining the groove 124b as a guide surface (hereinafter also referred to as the surface of the groove 124b).

Next, the second drive mechanism 123 is driven to move the jig 121 downward while keeping the outer peripheral portion of the substrate W in contact with the surface of the groove 124b. As a result, the bending of the substrate W is gradually eliminated, and the portion of the substrate W that contacts the surface of the groove 124b sequentially moves outward in the circumferential direction. However, since the groove 124b is inclined, such movement is not possible. be.

Next, referring to FIG. 5B, when the substrate W is flatly placed on the substrate placement surface 11a with no bending, the driving of the second driving mechanism 123 is stopped, and the treatment is performed. The downward movement of the tool 121 is stopped.

By supplying electric power to the electrode 12, the substrate W is attracted and held on the substrate mounting surface 11a by electrostatic force. It should be noted that the supply of electric power to the electrode 12 may be started before the substrate W is flatly placed, and the substrate W may be attracted to the substrate placement surface 11a by electrostatic force.

Finally, while the second drive mechanism 123 is driven to move the jig 121 downward, the first drive mechanism 122 is driven to rotate the jig 121 about the axis of the shaft portion 124a. As a result, the jig 121 spirally moves downward. At this time, the height position of the outer peripheral portion of the substrate W is maintained. The jig 121 then returns to its initial state. Even if the contact between the substrate W and the jig 121 is released, the substrate W can be held in a flat state because an electrostatic force is acting against the restoring force that restores the bending. .

As described above, since the bending of the substrate W is eliminated by driving the jig 121, unlike the technique disclosed in the above-mentioned Patent Document 1, the technique can be applied to the decompression process as well. Furthermore, since the jig 121 only abuts the surface of the groove 124b on the outer peripheral portion of the substrate W and does not contact the upper surface of the substrate W on which devices are formed, the upper surface of the substrate W is not contaminated. It is possible to suppress the risk of being

In addition, the jig of the present invention is not limited to the shape of the jigs 21 and 121 described above. For example, in the first embodiment described above, instead of the jig 21, as shown in FIG. In this case, the first designated direction W may be a direction parallel to the substrate mounting surface 11a and directed toward the center or a direction close thereto.

The first specified direction W1 and the second specified direction W2 of the present invention are not limited to the directions described above. For example, in the above-described first embodiment, the second designated direction W2 may not be the vertical direction, but may be a direction that is slanted so as to extend downward and outward from the vertical direction.

DESCRIPTION OF SYMBOLS 10... Electrostatic chuck 11... Base|substrate 11a... Substrate mounting surface 12... Electrode 13... Terminal 14... Current supply member 20, 120... Correction apparatus 21, 121... Jig 22, 122... No. 1 drive mechanism 23, 123 second drive mechanism 24 shaft 25, 35 claw 25a, 35a guide surface 124 threaded portion 124a shaft 124b helical groove 125... Lower portion 100, 200... Electrostatic chuck device W... Substrate W1... First specified direction W2... Second specified direction.

Claims (4)

An electrostatic chuck device comprising: an electrostatic chuck having a substrate mounting surface on which a substrate is mounted; and a correction device for correcting the shape of the substrate mounted on the substrate mounting surface,
The correction device
a jig;
a first drive mechanism that drives the jig in a first specified direction;
a second drive mechanism for driving the jig in a second specified direction;
The jig is a guide surface extending in a direction inclined with respect to the substrate mounting surface, and is positioned above the outer peripheral portion of the substrate in the driving process in the first designated direction by the first driving mechanism. and a guide surface that brings the outer peripheral portion of the substrate closer to the substrate mounting surface while contacting the outer peripheral portion of the substrate in the subsequent driving process in the second designated direction by the second driving mechanism. An electrostatic chuck device characterized by: The jig has a shaft portion extending in a direction perpendicular to the substrate mounting surface, and a claw portion protruding from a portion of the shaft portion in a circumferential direction and having the guide surface,
The first specified direction is a direction around the axis of the shaft portion positioned outside the substrate mounting surface,
2. The electrostatic chuck device according to claim 1, wherein said second specified direction is a downward direction in a direction perpendicular to said substrate mounting surface. The jig has a shaft portion extending in a direction perpendicular to the substrate mounting surface and a spiral groove formed on an outer peripheral surface of the shaft portion,
at least a portion of the wall surface of the shaft portion defining the groove constitutes the guide surface;
The first specified direction is a direction around the axis of the shaft portion positioned outside the substrate mounting surface,
2. The electrostatic chuck device according to claim 1, wherein said second specified direction is a downward direction in a direction perpendicular to said substrate mounting surface. the first specified direction is parallel to the substrate mounting surface and is a direction from the outside to the inside of the substrate mounting surface;
2. The electrostatic chuck device according to claim 1, wherein said second specified direction is a downward direction in a direction perpendicular to said substrate mounting surface.

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