JP2020072176A - Sample holding tool - Google Patents

Abstract

To provide a sample holding tool that can reduce the possibility that when plasma is generated inside a through hole, short circuit occurs.SOLUTION: A sample holding tool comprises an insulating substrate 1 that has a sample holding surface, and a support 2 that is joined to the insulating substrate 1, and a through hole 9 provided in the insulating substrate 1 and a hole part 7 provided in the support 2 are communicated with each other to form a gas inflow hole. A cylindrical sleeve 10 is arranged inside the hole part 7, and an annular insulating member 4 having a smaller modulus of elasticity than that of the sleeve 10 is provided between the sleeve 10 and the insulating substrate 1. The insulating member 4 is pinch-pressed by the sleeve 10 and the insulating substrate 1.SELECTED DRAWING: Figure 3

Description

  The present disclosure relates to a sample holder that holds a sample such as a semiconductor wafer used in a manufacturing process of a semiconductor integrated circuit, a manufacturing process of a liquid crystal display device, or the like.

  As a sample holder used in a semiconductor manufacturing apparatus or the like, for example, an electrostatic chuck described in Patent Document 1 is known. The electrostatic chuck described in Patent Document 1 includes an insulator and a metal base, and a through hole that penetrates the insulator and the metal base is provided. The through hole has a boundary portion between the insulator and the metal base. An insulating sleeve is arranged to cover the.

JP, 2004-31665, A

  In the electrostatic chuck described in Patent Document 1, when plasma is generated inside the through hole, there is a possibility that a short circuit may occur between the inside of the through hole and the metal base. Therefore, it is difficult to improve the long-term reliability of the electrostatic chuck.

  The sample holder of the present disclosure includes a plate-shaped ceramic body having one main surface as a sample holding surface, a support body having one main surface joined to the other main surface of the ceramic body, and a support body of the support body. A hole penetrating from one main surface to the other main surface, a cylindrical sleeve located in the hole, a sleeve located between the end surface of the sleeve and the other main surface of the ceramic body, An annular insulating member having a smaller elastic modulus than the insulating member, and the insulating member is narrowed by the sleeve and the ceramic body.

  According to the sample holder of the present disclosure, the insulating member improves the sealing property between the inside of the through hole and the support, and can suppress a short circuit when plasma is generated. Thereby, the long-term reliability of the sample holder can be improved.

It is a top view which shows one Embodiment of the sample holder of this indication. It is sectional drawing when it cut | disconnects by the cut surface line AA of the sample holder shown in FIG. It is the partial expanded sectional view which expanded the area | region B of the sample holder shown in FIG. It is a partial expanded sectional view showing other embodiments of a sample holder. It is a partial expanded sectional view showing other embodiments of a sample holder. It is a partial expanded sectional view showing other embodiments of a sample holder. It is a partial expanded sectional view showing other embodiments of a sample holder. It is a partial expanded sectional view showing other embodiments of a sample holder.

  Hereinafter, the sample holder 100 will be described with reference to the drawings. FIG. 1 is a plan view showing an embodiment of the sample holder of the present disclosure. The sample holder 100 includes an insulating base body 1, a support body 2, a bonding layer 3, an insulating member 4, and a sleeve 10.

  The insulating substrate 1 is a ceramic body having a first surface (one main surface) 1a and a second surface (the other main surface) 1b opposite to the first surface 1a, and the first surface 1a is a sample. It is a sample holding surface for holding. The insulating base 1 is a plate-shaped member, and the outer shape thereof is not limited, and may be, for example, a disk-shaped or a rectangular plate-shaped.

  The insulating substrate 1 is made of, for example, a ceramic material. As the ceramic material, for example, alumina, aluminum nitride, silicon nitride, yttria, or the like can be used. The outer dimensions of the insulating base 1 can be, for example, 200 to 500 mm in diameter (or side length) and 2 to 15 mm in thickness.

  Various methods can be used as a method of holding the sample using the insulating base 1. The sample holder 100 of this example is an electrostatic chuck that holds a sample by electrostatic force. Therefore, the sample holder 100 includes the adsorption electrode 6 inside the insulating substrate 1. The adsorption electrode 6 has two electrodes. One of the two electrodes is connected to the positive electrode of the power source, and the other is connected to the negative electrode. Each of the two electrodes has a substantially semi-circular plate shape, and is located inside the insulating base 1 so that the chords of the semi-circles face each other. By combining these two electrodes, the entire outer shape of the adsorption electrode 6 is circular. The center of the circular outer shape of the entire suction electrode 6 can be set to be the same as the center of the outer shape of the circular ceramic body. The adsorption electrode 6 has, for example, a metal material. The metal material includes, for example, a metal material such as platinum, tungsten or molybdenum.

  The sample holder 100 is used, for example, by generating plasma above the first surface 1a of the insulating substrate 1 which is the sample holding surface. Plasma can be generated by exciting a gas located between electrodes by applying a high frequency between a plurality of electrodes provided outside, for example.

  The support 2 is made of metal and is a member for supporting the insulating base 1. As the metal material, for example, aluminum can be used. The outer shape of the support 2 is not particularly limited, and may be circular or square. The outer dimensions of the support 2 can be, for example, 200 to 500 mm in diameter (or side length) and 10 to 100 mm in thickness. The support body 2 may have the same outer shape as the insulating base 1, may have a different outer shape, may have the same outer dimension, or may have different outer dimension.

  The support 2 and the insulating substrate 1 are joined together via the joining layer 3. Specifically, the first surface 2 a of the support body 2 and the second surface 1 b of the insulating base 1 are joined by the joining layer 3. As the bonding layer 3, for example, an adhesive made of a resin material can be used. As the resin material, for example, silicone resin can be used.

  As shown in FIGS. 2 and 3, the support 2 has a hole portion penetrating from the first surface (one main surface) 2a to the second surface (the other main surface) 2b opposite to the first surface 2a. 7 is provided. The insulating substrate 1 is also provided with a through hole 9 penetrating from the first surface 1a to the second surface 1b. The hole portion 7 and the through hole 9 are in communication with each other, and are continuous holes from the first surface 1a of the insulating substrate 1 to the second surface 2b of the support body 2 through the bonding layer 3. The hole portion 7 and the through hole 9 are, for example, gas inlet holes for allowing a gas such as helium to flow from the second surface 2b side of the support body 2 to the first surface 1a side of the insulating substrate 1 which is the sample holding surface. It is provided.

  The through hole 9 has a hole diameter smaller than the hole diameter of the hole portion 7 of the support 2 and the hole diameter of the bonding layer 3 in at least a part of the insulating base 1. In the sample holder 100 of this example, the hole portion 7 has a cylindrical shape with a constant hole diameter from the second surface 2b to the first surface 2a of the support 2. Further, the through hole 9 is a columnar shape having a constant hole diameter in the insulating base 1 from the second surface 1b to the first surface 1a of the insulating base 1. In the present embodiment, the second surface 1b of the insulating substrate 1 has a columnar shape having the same diameter as the hole 7 for communicating with the hole 7 of the support 2 and is located on the first surface 1a side. A recess 8 is provided.

  The sample holder 100 includes a sleeve 10 located in the hole 7. The sleeve 10 has a cylindrical shape extending along the central axis of the hole 7, and is made of an insulating material. The sleeve 10 covers the inner peripheral surface of the hole 7 where the metal material is exposed. By providing the sleeve 10 in the hole portion 7, the internal space of the sleeve 10 and the through hole 9 communicate with each other, and thus the gas inflow hole is formed. The sleeve 10 of the present embodiment has a right cylindrical shape, and the end surface 11 on the insulating base 1 side is parallel to a virtual plane orthogonal to the central axis.

  As described above, when the sample holder 100 is used, plasma is generated above the sample holding surface, but the generated plasma may travel through the through hole 9 and enter the hole 7. In that case, a short circuit occurs between the inner peripheral surface of the hole 7 and the support 2 is damaged. An insulating sleeve 10 is provided in the hole 7 in order to suppress a plasma short circuit.

  As the insulating material forming the sleeve 10, for example, a ceramic material can be used. Examples of the ceramic material include alumina and aluminum nitride. In the conventional structure, the end surface 11 of the sleeve 10 on the insulating base 1 side is brought into contact with the second surface 1b of the insulating base 1. For example, both the insulating substrate 1 and the sleeve 10 are made of a ceramic material, and there is a case where sufficient airtightness cannot be secured at the interfaces contacting each other. In that case, even if the sleeve 10 is provided, a short circuit due to plasma cannot be sufficiently suppressed.

  In the present embodiment, the annular insulating member 4 located between the end surface 11 of the sleeve 10 and the second surface 1b of the insulating base 1 is provided. The insulating member 4 is provided such that the center axis of the ring is parallel to the center axes of the through hole 9 and the sleeve 10, and these center axes preferably coincide with each other and are coaxial. The insulating member 4 is made of an insulating material having a smaller elastic modulus than the sleeve 10, and is narrowed by the sleeve 10 and the insulating base 1. A compressive force acts on the insulating member 4 in the central axis direction by the end surface 11 of the sleeve 10 and the second surface 1b of the insulating base 1. The insulating member 4 has a smaller elastic modulus than the insulating base 1 and the sleeve 10, and is elastically deformed by the narrow pressure between the sleeve 10 and the insulating base 1. By providing the insulating member 4, it is possible to sufficiently secure the airtightness (sealability) between the end surface 11 of the sleeve 10 and the second surface 1b of the insulating base 1. As a result, it is possible to sufficiently prevent the plasma that has entered the hole 7 from short-circuiting with the support 2, and it is possible to improve the long-term reliability of the sample holder 100.

  The insulating member 4 can be narrowed by previously disposing the insulating member 4 in the hole 7, inserting the sleeve 10 into the hole 7, and applying a force in the axial direction. The sleeve 10 can hold the insulating member 4 in a narrow pressure state by the insulating base 1 and the sleeve 10 by adhering and fixing the outer peripheral surface and the inner peripheral surface of the hole portion 7 with an adhesive or the like. it can.

  As the insulating material forming the insulating member 4, any material can be used as long as it has a smaller elastic modulus than the sleeve 10 and is resistant to plasma, and is, for example, a fluororesin. The shape of the insulating member 4 is annular, and for example, the cross-sectional shape in a cutting plane parallel to the central axis is circular. The cross-sectional shape is not limited to the circular shape, and may be a rectangular shape or a polygonal shape.

  4 to 8 are partially enlarged cross-sectional views showing another embodiment of the sample holder. In each of the following embodiments, the shape of the end surface 11 of the sleeve 10 is different. The configuration other than the shape of the end surface 11 of the sleeve 10 is the same as that of the sample holder 100 of the above-described embodiment shown in FIGS.

  In the sleeve 10 of the embodiment shown in FIG. 4, the end surface 11 has a recess 11a. As shown in the figure, the insulating member 4 is fitted and fixed in the recess 11a. In the example shown in FIG. 4, the cross-sectional shape of the recess 11 a on the cut surface parallel to the central axis is arcuate, and matches the arc of the insulating member 4. The cross-sectional shape of the recess 11a is not limited to an arc shape, and may be a V-shape or a rectangular shape, but the opening width of the recess 11a is the maximum length in the cross-section of the insulating member 4 (if it is circular, Diameter)).

  Since the end surface 11 of the sleeve 10 has the recess 11a, the insulating member 4 is fixed to the recess 11a, unnecessary deformation of the insulating member 4 is suppressed, and the displacement of the insulating member 4 in the hole 7 (axis shift). Can be suppressed.

  In the sleeve 10 of the embodiment shown in FIG. 5, the end surface 11 has the inclined portion 11b. The inclined portion 11b of the present embodiment is inclined inward in the axial direction as it goes inward in the radial direction of the sleeve 10. The insulating member 4 is narrowed by the inclined portion 11b and the second surface 1b of the insulating base 1. Due to the inclination of the inclined portion 11b, a force for compressing in the direction parallel to the axial direction and a force for compressing inward in the radial direction are applied to the insulating member 4. Thereby, the stress on the bonding layer 3 due to the insulating member 4 can be reduced. Therefore, the durability of the bonding layer 3 can be improved.

  In the sleeve 10 of the embodiment shown in FIG. 6, the end surface 11 has the inclined portion 11c. Unlike the inclined portion 11b shown in FIG. 5, the inclined portion 11c of this embodiment is inclined outward in the axial direction as it goes inward in the radial direction of the sleeve 10. The insulating member 4 is narrowed by the inclined portion 11c and the second surface 1b of the insulating base 1. Due to the inclination of the inclined portion 11c, a force that compresses in a direction parallel to the axial direction and a force that extends outward in the radial direction are applied to the insulating member 4. As a result, the contact area between the support 2 and the sleeve 10 can be reduced. Therefore, the thermal stress between the support 2 and the sleeve 10 can be reduced under the heat cycle when the sample holder 100 is used. As a result, it is possible to reduce the risk of the sleeve 10 being damaged.

  In the sleeve 10 of the embodiment shown in FIG. 7, the end surface 11 has a step portion 11d. In the present embodiment, the stepped portion 11d is low on the radially outer side 11d1 of the sleeve 10 and high on the radially inner side 11d2. The radially inner side 11d2 is annular, and the insulating member 4 is located on the radially outer side 11d1 so as to surround the annular radially inner side 11d2. The insulating member 4 is squeezed between the second surface 1b of the insulating base 1 and the radially outer side 11d1 of the step portion 11d. The annular inner side 11d2 in the radial direction can suppress unnecessary deformation of the insulating member 4 and can suppress positional displacement (axial line displacement) of the insulating member 4 in the hole 7.

  In the sleeve 10 of the embodiment shown in FIG. 8, the end surface 11 has the stepped portion 11d as in FIG. 7, but the radially inner side 11d3 is higher, and the radially inner side 11d3 is the insulating base 1. Is in contact with the second surface 1b. The height of the radially inner side 11d3 (the length extending in the axial direction with respect to the radially outer side 11d1) is such that the insulating member 4 is narrowed and elastically deformed to ensure sufficient sealing performance. The cross-sectional diameter of the insulating member 4 before being narrowed may be smaller than that of the insulating member 4. The same effect as that of the embodiment shown in FIG. 7 is obtained, and the depth at which the sleeve 10 is inserted into the hole 7 is defined. As a result, it is possible to suppress an excessive compressive force from being applied to the insulating member 4 and reduce unnecessary deformation and damage of the insulating member 4.

1: Insulating substrate 2: Support 3: Bonding layer 4: Insulating member 6: Adsorption electrode 7: Hole 8: First recess 9: Through hole 10: Sleeve 100: Sample holder

Claims (7)

A plate-shaped ceramic body whose one main surface is a sample holding surface,
A support having one main surface joined to the other main surface of the ceramic body,
A hole penetrating from one main surface of the support to the other main surface;
A tubular sleeve located in the hole,
An annular insulating member located between the end surface of the sleeve and the other main surface of the ceramic body and having a smaller elastic modulus than the sleeve;
The sample holder, wherein the insulating member is narrowed by the sleeve and the ceramic body.   The sample holder according to claim 1, wherein the end surface has a concave portion.   The sample holder according to claim 2, wherein the insulating member is fixed to the recess.   The sample holder according to claim 1, wherein the end surface has an inclined portion.   The sample holder according to claim 1, wherein the end surface has a step portion.   The sample holder according to claim 5, wherein the step portion has a lower radial outer side and a higher radial inner side.   The sample holder according to claim 1, wherein at least a part of the end surface of the sleeve is located away from the other main surface of the ceramic body.

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