JP6226563B2 - Electrostatic holding device and method for removing object to be held from electrostatic holding device - Google Patents

Description

The present invention relates to an electrostatic holding device and a method for detaching a holding object from the electrostatic holding device.

Conventionally, an electrostatic chuck stage that holds a semiconductor wafer (hereinafter sometimes simply referred to as a wafer) by static electricity is known (see, for example, Patent Document 1).
The electrostatic chuck stage (electrostatic holding device) described in Patent Document 1 has a plurality of dielectric films that cover the upper surfaces of the inner electrode and the outer electrode of the electrostatic chuck and a gap between the inner electrode and the outer electrode at equal intervals. The resistivity of the dielectric film is set to 10 ¹¹ to 10 ¹² Ωcm or 10 ¹⁷ Ωcm or more, and the ratio of the radius of the circle in which the plurality of lift pins are arranged to the radius of the wafer (holding object) By setting it to a predetermined ratio, the residual attracting force is reduced, and the object to be held is easily detached from the electrostatic chuck.

Japanese Patent Laid-Open No. 11-233605

  However, in the conventional electrostatic holding device as described in Patent Document 1, even if the resistivity of the dielectric film and the arrangement of the plurality of lift pins are set as described above, the residual attractive force remains. This residual attraction force has the disadvantage that it prevents the holding object from being detached.

  An object of the present invention is to provide an electrostatic holding device that can easily detach a holding object and a method for detaching the holding object from the electrostatic holding device.

In order to achieve the above object, an electrostatic holding device of the present invention is configured to be deformable, and supports an electrostatic chuck that attracts and holds an object to be held by static electricity, and supports the electrostatic chuck. A table body capable of forming a sealed space between the chuck and a fluid is supplied to the sealed space to bulge the electrostatic chuck, thereby reducing a contact area between the electrostatic chuck and the object to be held. The structure of having a contact area reduction means to be used is adopted.

In addition, another electrostatic holding device of the present invention is configured to be able to deform and hold an electrostatic chuck that attracts and holds an object to be held by static electricity, a table body that supports the electrostatic chuck, and the table body. A deformable member provided so as to form a sealed space that encloses the electrostatic chuck in a plan view of the table body, and supplying the fluid to the sealed space to bulge the deformable member, A configuration is adopted in which contact area reduction means for reducing the contact area between the deformable member and the object to be held is provided.

On the other hand, the method for detaching the object to be held from the electrostatic holding apparatus according to the present invention is configured to be deformable, and supports the electrostatic chuck that attracts the object to be held by static electricity, and supports the electrostatic chuck. A table main body capable of forming a sealed space between and a step of attracting and holding an object to be held by the electrostatic chuck; and supplying a fluid to the sealed space to bulge the electrostatic chuck; A configuration is adopted that includes a step of reducing the contact area between the electrostatic chuck and the object to be held.

Further, the method for detaching the object to be held from the other electrostatic holding apparatus of the present invention is configured to be deformable, and an electrostatic chuck that attracts the object to be held by static electricity, a table body that supports the electrostatic chuck. And a deformable member provided so as to form a sealed space that encloses the electrostatic chuck in plan view of the table main body between the table main body and the electrostatic chuck by sandwiching the deformable member therebetween Attracting and holding a holding object, and supplying a fluid to the sealed space to bulge the deforming member, and reducing the contact area between the deforming member and the holding object. The configuration is adopted.

  According to the present invention as described above, since the contact area reducing means is provided, the contact area between the object to be held and the electrostatic chuck or the deformable member can be reduced and then separated from each other. The influence of the residual attraction force that hinders the detachment of the object and the close contact thereof can be released, and the object to be held can be easily detached. In addition, since it is not necessary to use a lift pin, it is possible to eliminate the insertion hole for the lift pin, and it is possible to prevent the object to be held from being damaged by the insertion hole.

The side view of the sheet sticking apparatus which concerns on 1st, 2nd embodiment of this invention. (A), (B), (C) is operation | movement explanatory drawing of a sheet sticking apparatus.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
Detailed description of the same configuration and operation in each embodiment will be omitted.
Further, in the first and second embodiments, for example, when a direction such as up, down, left, right, near side, or back side is shown without giving a reference figure, FIG. Based on the case of viewing from (the direction in which the number assigned is an appropriate direction), the up, down, left, and right directions are directions parallel to the paper surface, and the front and back directions are directions orthogonal to the paper surface.

  1 and 2, the sheet sticking apparatus 1 includes an electrostatic holding device 2 that holds a wafer WF as a holding object, and a pressing unit 3 that presses and sticks the adhesive sheet AS to the wafer WF.

  The electrostatic holding device 2 is configured to be deformable, and supports the first electrostatic chuck 21 as an electrostatic chuck that attracts the wafer WF by static electricity, supports the first electrostatic chuck 21, and the first electrostatic chuck 21. And the table body 22 capable of forming a first sealed space SP1 as a sealed space between the two, and air as a fluid is supplied to the first sealed space SP1 to cause the first electrostatic chuck 21 to bulge. A contact area reducing means 23 for reducing the contact area between the first electrostatic chuck 21 and the wafer WF, and a removal assisting means 24 (see FIG. 2B) for assisting the removal of the wafer WF from the first electrostatic chuck 21. It has.

The first electrostatic chuck 21 is configured to generate positive and negative charges and attract the wafer WF by Coulomb force, hold the electrode 21A on the front surface, back surface, or inside, and be deformable by rubber, resin, or the like. The deformed member 21B is provided. The electrode 21A may be either deformable or non-deformable.
The table body 22 includes a substantially box-shaped lower case 22A having an upper surface opened, and a table 22B provided on the inner bottom surface of the lower case 22A. The inner bottom surface of the lower case 22A includes the entire table 22B. The outer edge portion of the first electrostatic chuck 21 provided so as to be supported is supported.
The contact area reducing means 23 communicates with the first sealed space SP1 through the pipe 23A, and pressurizing means such as a pressurizing pump and a turbine capable of pressurizing the first sealed space SP1 and the first sealed space SP1 are decompressed. A first pressure adjusting means 23B having a pressure reducing means such as a pressure reducing pump, a vacuum ejector, and an on-off valve is provided.
The separation assisting unit 24 is illustrated as a driving plate that moves the support plate 24B and a support plate 24B having a holding surface 24A that can hold the wafer WF and the adhesive sheet AS by suction means such as a decompression pump and a vacuum ejector (not shown). Equipped with an unjointed robot.

The pressing means 3 is supported by an output shaft 32 of a direct acting motor 31 as a driving device, and an upper case whose lower surface is opened and can form a second sealed space SP2 (see FIG. 2A) with the lower case 22A. 33 and the upper case 33 so that a third sealed space SP3 (see FIG. 2A) can be formed, and an outer edge portion thereof is supported on the inner upper surface of the upper case 33. The second electrostatic chuck 34 that attracts the adhesive sheet AS by static electricity, the first pressurizing / depressurizing means 35 that can pressurize or depressurize the second sealed space SP2, and the second that can pressurize or depressurize the third sealed space SP3. And a pressure increasing / decreasing means 36.
The second electrostatic chuck 34 includes an electrode 34 </ b> A and a deformation member 34 </ b> B equivalent to the first electrostatic chuck 21.
The first and second pressure increasing / decreasing means 35, 36 are communicated with the second and third sealed spaces SP2, SP3 via pipes 35A, 36A, respectively, and second and third equivalent to the first pressure adjusting means 23B, respectively. Pressure adjusting means 35B and 36B are provided.

In the sheet sticking apparatus 1 described above, a procedure for sticking the adhesive sheet AS to the wafer WF will be described.
First, as shown by the solid line in FIG. 1, with the upper case 33 being separated from the lower case 22A, the detachment assisting means 24 drives the articulated robot (not shown), and the adhesive sheet AS held by suction with the support plate 24B is moved upward. When contacting the second electrostatic chuck 34 of the case 33, the pressing means 3 drives the second electrostatic chuck 34 to attract and hold the adhesive sheet AS. Further, when the disengagement assisting unit 24 drives an articulated robot (not shown) and the wafer WF attracted and held by the support plate 24B is brought into contact with the first electrostatic chuck 21, the electrostatic holding device 2 is moved to the first electrostatic chuck 21. To attract and hold the wafer WF.

  Next, after the pressing means 3 drives the linear motor 31 to lower the upper case 33 to form the second sealed space SP2, the pressing means 3 drives the first and second pressure-increasing / decreasing means 35, 36. When the detection means (not shown) detects that the second and third sealed spaces SP2 and SP3 are depressurized at the same depressurization rate and a predetermined pressure is detected, the first and second pressure increase and depressurization means 35 and 36 Stop driving. After that, the pressing means 3 drives the first pressure increasing / decreasing means 35 or the second pressure increasing / decreasing means 36 to increase the pressure of the third sealed space SP3 with respect to the second sealed space SP2, whereby FIG. ), The second electrostatic chuck 34 is bulged, and the adhesive sheet AS is pressed and stuck to the wafer WF.

  Next, the pressing means 3 stops the driving of the second electrostatic chuck 34, drives the first pressure increasing / decreasing means 35 or the second pressure increasing / decreasing means 36, and controls the pressures of the second and third sealed spaces SP2, SP3. By making them equal, the second electrostatic chuck 34 is detached from the adhesive sheet AS and returned to the state before bulging. Then, the pressing means 3 drives the first and second pressure-reducing means 35 and 36, and pressurizes the second and third sealed spaces SP2 and SP3 at the same pressurization rate to be a predetermined pressure (atmospheric pressure). Is detected by a detection means (not shown), the driving of the first and second pressure-intensifying means 35, 36 is stopped. Next, the pressing means 3 drives the linear motor 31 to move the upper case 33 upward. Next, the detachment assisting means 24 drives an articulated robot (not shown), and as shown in FIG. 2B, the holding surface 24A of the support plate 24B is brought into contact with the adhesive sheet AS, and the suction means (not shown) is driven. After holding the adhesive sheet AS, the electrostatic holding device 2 stops driving the first electrostatic chuck 21 and releases the holding of the wafer WF.

  Thereafter, the removal assisting means 24 drives an articulated robot (not shown), and the wafer WF with the adhesive sheet AS attached thereto is removed from the first electrostatic chuck 21. The wafer WF and the first electrostatic chuck 21 There may be a case where a residual attractive force remains between them or a close contact due to wettability. In such a case, in the case of a configuration in which the wafer WF is attracted and held instead of electrostatically held, a small amount of air can be protruded from the suction hole to release the contact, but in the case of electrostatic holding, The contact cannot be released. Therefore, the electrostatic holding device 2 drives the contact area reducing means 23 to supply the air to the first sealed space SP1 and bulge the first electrostatic chuck 21 as shown in FIG. The contact area between the first electrostatic chuck 21 and the wafer WF is reduced. At this time, since the wafer WF to which the adhesive sheet AS is stuck rises, the detachment assisting means 24 drives the articulated robot (not shown) and raises the support plate 24B accordingly. Accordingly, it is possible to prevent the wafer WF from being bent and damaged as the first electrostatic chuck 21 bulges, or from being dropped from the first electrostatic chuck 21 and damaged. When the detection means (not shown) detects that the first electrostatic chuck 21 has expanded by a predetermined amount, the detachment assisting means 24 drives the articulated robot (not shown), and the wafer WF with the adhesive sheet AS attached is processed in the next step. 1 and the electrostatic holding device 2 drives the contact area reducing means 23 to discharge air from the first sealed space SP1, so that the first electrostatic chuck 21 is in a state before bulging indicated by a solid line in FIG. The operation similar to the above is repeated thereafter.

  According to the embodiment as described above, since the contact area reducing unit 23 is provided, the contact area between the wafer WF and the first electrostatic chuck 21 can be reduced and then separated from each other. It is possible to release the influence of the residual attracting force that hinders the separation of the wafer and the close contact therebetween, and the wafer WF can be easily detached.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.
As shown in FIGS. 1 and 2, the sheet sticking apparatus 1 </ b> A of the second embodiment is an electrostatic chuck that attracts the wafer WF by static electricity instead of the electrostatic holding apparatus 2 with respect to the sheet sticking apparatus 1 of the first embodiment. The first electrostatic chuck 21 </ b> C (shown by a two-dot chain line in FIGS. 1 and 2), the table main body 22 that supports the first electrostatic chuck 21 </ b> C, and the table main body 22 are configured to be deformable. The deformable member 25 provided to form the first sealed space SP1 that encloses the electrostatic chuck 21C in a plan view of the table main body 22, and the deformed member 25 bulges by supplying air to the first sealed space SP1. Thus, the difference is that the electrostatic holding device 2A including the contact area reducing unit 23 that reduces the contact area between the deformable member 25 and the wafer WF is provided. Note that the first sealed space SP1 includes the electrostatic chuck 21C in a plan view of the table body 22 when the first sealed space SP1 is viewed from above in FIG. 1 within the region of the first sealed space SP1. It means that the electrostatic chuck 21C exists. Similar to the first electrostatic chuck 21 of the first embodiment, the deformable member 25 has an outer edge supported by the inner bottom surface of the lower case 22A so as to enclose the entire table 22B. The first electrostatic chuck 21C is composed of electrodes that generate positive and negative charges and attract the wafer WF by Coulomb force, and is held on the front surface, back surface, or inside of the table 22B.
As for the operation of the sheet sticking apparatus 1A, the wafer WF is attracted and held by the first electrostatic chuck 21C with the deformation member 25 interposed therebetween, and the deformation member 25 is expanded by driving the contact area reducing means 23. The operation is the same as the operation of the sheet sticking apparatus 1 of the first embodiment except that the wafer WF to which the adhesive sheet AS is stuck is raised while reducing the contact area between the wafer WF and the deformable member 25. Omitted.

  The effects of the first embodiment can also be achieved by the second embodiment as described above.

  As described above, the best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, the invention has been illustrated and described with particular reference to certain specific embodiments, but without departing from the spirit and scope of the invention, Various modifications can be made by those skilled in the art in terms of material, quantity, and other detailed configurations. In addition, the description of the shape, material, and the like disclosed above is exemplary for ease of understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such restrictions is included in this invention.

For example, in each embodiment, the fluid supplied to the first sealed space SP1 by the contact area reducing unit 23 may be air, a single gas, a mixed gas, a liquid such as water or oil, a gel-like body, or the like.
In each embodiment, the adhesive sheet AS may be pressed and attached to the wafer WF in an atmosphere of atmospheric pressure or in the second sealed space SP2 with a pressure higher than atmospheric pressure.
Furthermore, in each embodiment, it is not necessary to provide the separation assisting means 24. In this case, the adhesive sheet AS and the wafer WF can be manually transferred.
Further, in each embodiment, instead of the second electrostatic chuck 34 and the second pressure increasing / decreasing means 36, it is supported by an output shaft of a direct acting motor as a driving device, and by a suction means such as a decompression pump or a vacuum ejector not shown. A holding table capable of sucking and holding the adhesive sheet AS may be provided.
Furthermore, an electrostatic chuck that attracts the wafer WF or the like by static electricity may be provided instead of the support plate 24B that can attract and hold the wafer WF or the like by the suction means of the separation assisting means 24.
The first electrostatic chuck 21 and the deformable member 25 may be elastically deformable or plastically deformable, and may not be completely restored to the original shape after being deformed.
Further, the table 22B may not be provided. In this case, the first electrostatic chuck 21C may be disposed on the surface or inside of the lower case 22A.
Moreover, it is good also as a structure which added the 1st electrostatic chuck 21C of 2nd Embodiment to the electrostatic holding | maintenance apparatus 2 of 1st Embodiment.

Further, the material, type, shape, etc. of the adhesive sheet AS and the holding object in the present invention are not particularly limited. For example, the adhesive sheet AS is not limited to adhesive forms such as pressure-sensitive adhesiveness and heat-sensitive adhesiveness. When a heat-sensitive adhesive is used, an appropriate heating means for heating the adhesive sheet AS. May be provided. Such an adhesive sheet AS is, for example, a single layer having only an adhesive layer, an intermediate layer between the base sheet and the adhesive layer, a cover layer on the upper surface of the base sheet, etc. Three or more layers, or a so-called double-sided adhesive sheet that can peel the base sheet from the adhesive layer may be used. The double-sided adhesive sheet comprises a single-layer or multi-layer intermediate layer. It may be a single layer or a multilayer having no intermediate layer. In addition, as the holding object, for example, food, resin containers, semiconductor wafers such as silicon semiconductor wafers and compound semiconductor wafers, circuit board, information recording substrates such as optical disks, glass plates, steel plates, ceramics, wood plates or resin plates, Arbitrary forms of members and articles can also be targeted. In addition, the adhesive sheet AS is replaced with a functional and intended reading, for example, any information label, decorative label, protective sheet, dicing tape, die attach film, die bonding tape, recording layer forming resin sheet, etc. Arbitrary shaped sheets, films, tapes, etc. can be attached to any holding object as described above.
Moreover, you may employ | adopt electrostatic holding | maintenance apparatus 2 and 2A to other apparatuses, such as a coating device and a test | inspection apparatus other than sheet sticking apparatus 1 and 1A. By adopting the electrostatic holding device 2 or 2A in a coating apparatus or an inspection apparatus, it is possible to easily remove the object to be held or the object to be inspected as a holding object, and perform coating or inspection without reducing efficiency. be able to.

The means and steps in the present invention are not limited in any way as long as they can perform the operations, functions, or steps described with respect to those means and steps. The process is not limited at all. For example, as long as the electrostatic chuck is configured to be deformable and attracts the object to be held by static electricity, it is not limited in any way as long as it is within the technical scope in light of the common general technical knowledge at the time of filing. (Description of other means and steps is omitted).
Further, the drive device in the embodiment includes an electric device such as a rotation motor, a linear motion motor, a linear motor, a single axis robot, an articulated robot, an actuator such as an air cylinder, a hydraulic cylinder, a rodless cylinder, and a rotary cylinder. In addition to these, a combination of them directly or indirectly may be employed (some of them overlap with those exemplified in the embodiment).

2, 2A ... Electrostatic holding device 21, 21C ... First electrostatic chuck (electrostatic chuck)
22 ... Table body 23 ... Contact area reducing means 25 ... Deformation member SP1 ... First sealed space (sealed space)
WF ... Wafer (object to be held)

Claims (4)

An electrostatic chuck configured to be deformable and attracting and holding an object to be held by static electricity;
A table body that supports the electrostatic chuck and can form a sealed space with the electrostatic chuck;
Contact area reducing means for reducing a contact area between the electrostatic chuck and the object to be held by supplying a fluid to the sealed space to bulge the electrostatic chuck is provided. Electrostatic holding device. An electrostatic chuck for attracting and holding an object to be held by static electricity;
A table body for supporting the electrostatic chuck;
A deformable member configured to be deformable and provided so as to form a sealed space containing the electrostatic chuck in a plan view of the table body between the table body and the table body;
An electrostatic system comprising: a contact area reducing unit that reduces a contact area between the deformable member and the object to be held by supplying a fluid to the sealed space to bulge the deformable member. Holding device. An electrostatic chuck which is configured to be deformable and attracts a holding object by static electricity;
Using the table body that supports the electrostatic chuck and can form a sealed space with the electrostatic chuck,
A step of holding attract the holding object by said electrostatic chuck,
A step of supplying a fluid to the sealed space to bulge the electrostatic chuck to reduce a contact area between the electrostatic chuck and the object to be held. How to remove the object to be held. An electrostatic chuck that attracts the object to be held by static electricity;
A table body for supporting the electrostatic chuck;
Using a deformable member that is configured to be deformable and provided so as to be able to form a sealed space that encloses the electrostatic chuck in plan view of the table body,
A step of holding attract the holding object by an electrostatic chuck in between said deformable member,
Holding from the electrostatic holding device, comprising: supplying a fluid to the sealed space to bulge the deformable member to reduce a contact area between the deformable member and the object to be held. How to remove the object.

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