Sample holder

Abstract

To provide a sample holding tool capable of suppressing an abnormal discharge in a flow channel.SOLUTION: A sample holding tool comprises a ceramic substrate, a base plate, and an embedded member. The ceramic substrate includes: a first surface on which a processed body is mounted; a second surface that is positioned on the side opposite to the first surface; and a first flow channel that penetrates between the first surface and the second surface. The base plate is bonded to the second surface of the ceramic substrate, and includes a penetration hole at a position corresponded to at least the first flow channel. The embedded member includes a madreporic body at an end part on the first flow channel side in the penetration hole, and includes a second flow channel communicated with the first flow channel via the madreporic body. In addition, the second flow channel includes: a first portion that is vertical to the first surface; and a second portion that crosses the first portion.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION The disclosed embodiments relate to a sample holder. [Background technology]

[0002] In the process of manufacturing semiconductor parts, electrostatic chucks are used as sample holders to hold workpieces such as semiconductor wafers that are to be subjected to plasma processing. These electrostatic chucks are constructed, for example, by bonding a ceramic substrate with an embedded electrode to a metal base plate.

[0003] This electrostatic chuck has a flow path formed therein for supplying a heat transfer gas for temperature control to a workpiece placed on the electrostatic chuck. Also, from the viewpoint of suppressing the intrusion of plasma into the flow path, an electrostatic chuck has been proposed in which a porous body is disposed within the flow path (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2019-165223 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-mentioned conventional technology has room for further improvement in terms of suppressing abnormal discharge in the flow path.

[0006] One aspect of the embodiment has been made in view of the above, and aims to provide a sample holder that can suppress abnormal discharge in a flow channel. [Means for solving the problem]

[0007] A sample holder according to one aspect of the embodiment includes a ceramic substrate, a base plate, and an embedding member. The ceramic substrate has a first surface on which a workpiece is placed, a second surface opposite the first surface, and a first flow path extending between the first and second surfaces. The base plate is bonded to the second surface of the ceramic substrate and has a through-hole at a position corresponding to at least the first flow path. The embedding member has a porous body at an end of the through-hole facing the first flow path, and a second flow path communicating with the first flow path via the porous body. The second flow path has a first portion perpendicular to the first surface and a second portion intersecting the first portion. [Effects of the Invention]

[0008] According to one aspect of the embodiment, it is possible to provide a sample holder that can suppress abnormal discharge in a flow channel. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing the configuration of a sample holder according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing a cross section of the sample holder according to the embodiment. [Figure 3] FIG. 3 is an enlarged cross-sectional view showing the configuration of the embedded member and its surroundings according to the embodiment. [Figure 4] FIG. 4 is a plan view showing an example of the configuration of the embedding member according to the embodiment as viewed from above. [Figure 5] FIG. 5 is an enlarged cross-sectional view showing the configuration of an embedded member and its surroundings according to the first modification of the embodiment. [Figure 6] FIG. 6 is a plan view showing an example of the configuration of an embedding member according to the first modification of the embodiment, as viewed from above. [Figure 7] FIG. 7 is an enlarged cross-sectional view showing the configuration of an embedded member and its surroundings according to the second modification of the embodiment. [Figure 8] FIG. 8 is a plan view showing an example of the configuration of an embedding member according to the second modification of the embodiment, as viewed from above. [Figure 9] FIG. 9 is an enlarged cross-sectional view showing the configuration of an embedded member and its surroundings according to the third modification of the embodiment. [Figure 10] FIG. 10 is a plan view showing an example of the configuration of an embedding member according to the third modification of the embodiment, as viewed from above. [Figure 11] FIG. 11 is an enlarged cross-sectional view showing the configuration of an embedded member and its surroundings according to the fourth modification of the embodiment. [Figure 12] FIG. 12 is a plan view showing an example of the configuration of an embedding member according to the fourth modification of the embodiment, as viewed from above. [Figure 13] FIG. 13 is an enlarged cross-sectional view showing the configuration of an embedded member and its surroundings according to the fifth modification of the embodiment. [Figure 14] FIG. 14 is a plan view showing an example of the configuration of an embedding member according to the fifth modification of the embodiment, as viewed from above. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the sample holder disclosed in the present application will be described with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments shown below. Furthermore, each embodiment can be appropriately combined within the scope of not causing contradictions in the content. Furthermore, the same parts in each of the following embodiments will be given the same reference numerals, and duplicated explanations will be omitted.

[0011] Furthermore, in the embodiments described below, expressions such as "constant," "orthogonal," "perpendicular," or "parallel" may be used, but these expressions do not necessarily mean "constant," "orthogonal," "perpendicular," or "parallel" in the strict sense. For example, "perpendicular" means that the central axis of the first portion is 90°±2° relative to the first surface, and "parallel" means that the central axis of the second portion is 0°±2° relative to the first surface. In other words, the above expressions allow for deviations due to, for example, manufacturing precision, installation precision, etc.

[0012] <Embodiment> First, the configuration of the sample holder 100 according to the embodiment will be described with reference to Figures 1 to 4. Figure 1 is a perspective view showing the configuration of the sample holder 100 according to the embodiment. As shown in Figure 1, the sample holder 100 has a structure in which a ceramic substrate 110 and a base plate 120 are joined together.

[0013] The ceramic substrate 110 utilizes electrostatic force to adsorb an object to be processed (not shown), such as a semiconductor wafer, etc. The ceramic substrate 110 is a member formed into a substantially circular disk shape from a raw material containing ceramic.

[0014] The ceramic substrate 110 contains, for example, aluminum oxide (Al2O3), aluminum nitride (AlN), yttria (Y2O3), cordierite, silicon carbide (SiC), silicon nitride (Si3N4), or the like as a main component.

[0015] The base plate 120 is a support member that supports the ceramic substrate 110. The base plate 120 is attached to, for example, a semiconductor manufacturing device, and causes the sample holder 100 to function as a semiconductor holder that holds an object to be processed, such as a semiconductor wafer.

[0016] The base plate 120 is a circular metal member. Examples of metal materials that can be used to form the base plate 120 include aluminum, stainless steel, titanium, and aluminum-based composite materials such as AlSiC.

[0017] 2 is a schematic diagram showing a cross section of the sample holder 100 according to the embodiment. As described above, the sample holder 100 is formed by joining the ceramic substrate 110 and the base plate 120 together.

[0018] The ceramic substrate 110 has a first surface 110a and a second surface 110b. An object to be processed (not shown), such as a semiconductor wafer, is placed on the first surface 110a. The second surface 110b is located on the opposite side to the first surface 110a.

[0019] The object to be processed placed on the first surface 110a of the ceramic substrate 110 is subjected to plasma processing by generating plasma above the first surface 110a. This plasma can be generated by applying high-frequency power to an electrode (not shown) facing the first surface 110a to excite a gas.

[0020] An electrode 111 is disposed inside the ceramic substrate 110. The electrode 111 is, for example, an electrostatic attraction electrode, and is a conductive member containing a metal such as platinum, tungsten, or molybdenum. When a voltage is applied to the electrode 111, the sample holder 100 generates an electrostatic force, and the sample holder 100 functions as an electrostatic chuck, thereby attracting the workpiece to the first surface 110a of the ceramic substrate 110.

[0021] The base plate 120 is bonded to the second surface 110b of the ceramic substrate 110. The base plate 120 may be bonded to the second surface 110b via, for example, a bonding material. As such a bonding material, for example, an adhesive such as a silicone resin can be used.

[0022] The base plate 120 may have an internal space 121. The space 121 may be used as a coolant passage for passing a cooling medium such as cooling water or cooling gas. The base plate 120 may also function as a high-frequency electrode to which high-frequency power for generating plasma is applied.

[0023] As shown in FIG. 2, the ceramic substrate 110 has a first flow path 112 formed therein, which passes through the first surface 110a and the second surface 110b.

[0024] Furthermore, a through-hole 122 is formed in the base plate 120 at a position corresponding to at least the first flow path 112. Then, an embedding member 130 is disposed in the through-hole 122.

[0025] The embedding member 130 is a cylindrical member made of an insulating material such as aluminum oxide (Al2O3). When the recess 113 is provided on the second surface 110b of the ceramic substrate 110, the embedding member 130 may protrude toward the ceramic substrate 110 beyond the upper surface of the base plate 120 (i.e., the surface bonded to the second surface 110b) and fit into the recess 113.

[0026] As a result, the length of first flow path 112 is shortened at the position corresponding to recess 113 of ceramic substrate 110, and therefore, generation of plasma in first flow path 112 can be suppressed.

[0027] The embedded member 130 has a porous body 131 at the end on the first flow path 112 side. By positioning the porous body 131 at the end on the first flow path 112 side in this way, when plasma is generated above the first surface 110a of the ceramic substrate 110, it is possible to reduce the problem of the plasma passing through the first flow path 112 and reaching the base plate 120 side.

[0028] The porous body 131 is, for example, an alumina porous body or another ceramic porous body. The porous body 131 only needs to have pores to the extent that gas can flow through it. The porosity of the porous body 131 is, for example, 40% or more and 60% or less.

[0029] Furthermore, a second flow path 132 that communicates with the first flow path 112 via the porous body 131 is formed in the embedded member 130. The second flow path 132 and the first flow path 112 form a gas flow path that continues from the lower surface of the base plate 120, through the porous body 131, to the upper surface (first surface 110a) of the ceramic substrate 110.

[0030] A heat transfer gas such as helium may be flowed through second flow path 132 and first flow path 112. By flowing the heat transfer gas through second flow path 132 and first flow path 112, the heat transfer gas is supplied to the back surface of the workpiece placed on first surface 110a of ceramic substrate 110, improving the heat transfer coefficient between the workpiece and ceramic substrate 110.

[0031] Fig. 3 is an enlarged cross-sectional view showing the configuration of the embedding member 130 according to the embodiment and its surrounding area, and Fig. 4 is a plan view showing an example of the configuration of the embedding member 130 according to the embodiment as seen from above. Note that Fig. 4 and subsequent figures corresponding to Fig. 4 also show the position of the first flow path 112 formed in the ceramic substrate 110 (see Fig. 3) for ease of understanding.

[0032] 3 and other figures, in this embodiment, the second flow path 132 formed in the embedded member 130 has a first portion 132a and a second portion 132b. The first portion 132a is a portion perpendicular to the first surface 110a of the ceramic substrate 110.

[0033] The second portion 132b is a portion that intersects with the first portion 132a. In other words, the second portion 132b is a portion that extends in a different direction from the first portion 132a. For example, in this embodiment, the second portion 132b is parallel to the first surface 110a and is linear.

[0034] In the embodiment, two first portions 132a are connected by one second portion 132b to form the second flow path 132. As a result, the second flow path 132 has a shape that is bent midway inside the embedded member 130.

[0035] Of the two first portions 132a, the first portion 132a that is directly connected to the porous body 131 is positioned so as to overlap with the first flow path 112 in a plan view, as shown in Fig. 4. On the other hand, of the two first portions 132a, the first portion 132a that is not directly connected to the porous body 131 is positioned so as not to overlap with the first flow path 112 in a plan view.

[0036] Now, for example, it is assumed that first flow path 112 and second flow path 132 are positioned linearly from the upper surface (first surface 110a) of ceramic substrate 110 to the lower surface of base plate 120.

[0037] In this case, when plasma is generated above the first surface 110a, charged particles in the plasma may enter the first flow path 112 while maintaining high energy and reach the porous body 131 or the second flow path 132, which may cause abnormal discharge in the porous body 131 or the second flow path 132.

[0038] In contrast to this, in the embodiment, the second flow path 132 has a bent structure, that is, a labyrinth structure, as shown in Fig. 3 etc. As a result, even if charged particles in the plasma enter the first flow path 112 when the plasma is generated above the first surface 110a, the charged particles can be deactivated by colliding with the wall surface of the second flow path 132.

[0039] Furthermore, in the embodiment, the first flow path 112 and the second flow path 132 can be made longer in overall length than when they are positioned linearly from the first surface 110a of the ceramic substrate 110 to the lower surface of the base plate 120.

[0040] As a result, even if charged particles in the plasma enter the first flow path 112 when the plasma is generated above the first surface 110a, the charged particles can be deactivated midway through the long flow path.

[0041] As described above, in the embodiment, the second flow path 132 has a curved structure, which makes it possible to easily deactivate charged particles that have entered the second flow path 132, thereby suppressing the occurrence of abnormal discharges in the first flow path 112 and the second flow path 132.

[0042] The embedding member 130 according to the embodiment can be formed, for example, by stacking a cylindrical green sheet having a through hole corresponding to the first portion 132a and a cylindrical green sheet having a lateral hole corresponding to the second portion 132b to form a laminate, and then firing the laminate.

[0043] In the embodiment, by arranging the second portion 132b parallel to the first surface 110a, a green sheet can be easily formed in which a lateral hole corresponding to the second portion 132b is formed, and therefore the embedding member 130 can be easily formed.

[0044] In addition, the embedded member 130 according to the embodiment may be formed by arranging two semi-cylindrical molded bodies, each having a first portion 132a and a second portion 132b formed in a semi-cylindrical shape, pressing the pressed bodies together to form a cylindrical shape, and then firing the pressed bodies.

[0045] Furthermore, the embedding member 130 according to the embodiment may be formed by using a 3D printer to produce a cylindrical molded body in which the first portion 132a and the second portion 132b are formed, and then firing the molded body.

[0046] <Variation 1> Next, various modified examples of the embodiment will be described with reference to Fig. 5 to Fig. 14. Fig. 5 is an enlarged cross-sectional view showing the configuration of an embedding member 130 according to Modification 1 of the embodiment and its surroundings, and Fig. 6 is a plan view showing an example of the configuration of the embedding member 130 according to Modification 1 of the embodiment as viewed from above.

[0047] 5 and other figures, the sample holder 100 according to the first modification differs from the above-described embodiment in the configuration of the second flow path 132. Specifically, in the first modification, the second portion 132b of the second flow path 132 is positioned at an angle with respect to the first portion 132a and the first surface 110a.

[0048] This also allows charged particles in the plasma to be deactivated by colliding with the wall surface of the second flow path 132 when the plasma is generated above the first surface 110a and the charged particles in the plasma enter the first flow path 112.

[0049] Furthermore, in the first modification, even if charged particles in the plasma enter the first flow path 112, they can be deactivated midway through the long flow path. Therefore, according to the first modification, it is possible to suppress the occurrence of abnormal discharge in the first flow path 112 and the second flow path 132.

[0050] <Variation 2> Fig. 7 is an enlarged cross-sectional view showing the configuration of an embedded member 130 and its surroundings according to Modification 2 of the embodiment, and Fig. 8 is a plan view showing an example of the configuration of the embedded member 130 according to Modification 2 of the embodiment as viewed from above. As shown in Fig. 7, in Modification 2, the second flow path 132 has three first portions 132a and two second portions 132b.

[0051] Of the three first portions 132a, the first portion 132a directly connected to the porous body 131 and the first portion 132a farthest from the porous body 131 are positioned so as to overlap with the first flow path 112 in a plan view, as shown in Fig. 8. On the other hand, of the three first portions 132a, the first portion 132a located in the middle is positioned so as not to overlap with the first flow path 112 in a plan view.

[0052] In the second modification, three first portions 132a are connected by two second portions 132b to form the second flow path 132. As a result, the second flow path 132 in the second modification has a shape that is bent at multiple points along the way.

[0053] As a result, when plasma is generated above the first surface 110a, if charged particles in the plasma enter the first flow path 112, the charged particles can be caused to collide with the wall surface of the second flow path 132 and be effectively deactivated.

[0054] Furthermore, in variant 2, the overall length of the flow paths can be made even longer compared to when the first flow path 112 and the second flow path 132 are positioned in a straight line from the first surface 110a of the ceramic substrate 110 to the underside of the base plate 120.

[0055] This allows for the charged particles in the plasma to be effectively deactivated midway through the longer flow path when the plasma is generated above the first surface 110a and the charged particles in the plasma enter the first flow path 112.

[0056] In this way, in the second modification, second flow path 132 has a structure in which second flow path 132 is bent at a plurality of locations, so that the occurrence of abnormal discharge in first flow path 112 and second flow path 132 can be effectively suppressed.

[0057] In the example of Figure 7, the second flow path 132 has three first portions 132a and two second portions 132b, but the present disclosure is not limited to such an example, and the second flow path 132 may have four or more first portions 132a and three or more second portions 132b.

[0058] <Variation 3> Figure 9 is an enlarged cross-sectional view showing the configuration of the embedded member 130 and its surrounding area according to the third modification of the embodiment, and Figure 10 is a plan view showing an example of the configuration of the embedded member 130 according to the third modification of the embodiment as viewed from above.

[0059] 9 and other figures, in this modification 3, the two first portions 132a are positioned so as not to overlap with the first flow path 112 in a plan view. For example, one first portion 132a is positioned close to the periphery of the porous body 131, and the other first portion 132a is positioned close to the periphery of the porous body 131 on the opposite side to the one first portion 132a.

[0060] As a result, in variant example 3, when plasma is generated above the first surface 110a, if charged particles in the plasma enter the first flow path 112, the charged particles can be caused to collide with the wall surfaces of the voids in the porous body 131 or the wall surfaces of the second flow path 132, thereby effectively deactivating them.

[0061] Furthermore, in variant example 3, the overall length of the flow paths can be made even longer than when the first flow path 112 and the second flow path 132 are positioned in a straight line from the first surface 110a of the ceramic substrate 110 to the underside of the base plate 120.

[0062] This allows for the charged particles in the plasma to be effectively deactivated midway through the longer flow path when the plasma is generated above the first surface 110a and the charged particles in the plasma enter the first flow path 112.

[0063] In this way, in variant example 3, by positioning the first portion 132a of the second flow path 132 so that it does not overlap with the first flow path 112 in a planar view, the occurrence of abnormal discharge in the first flow path 112 and the second flow path 132 can be effectively suppressed.

[0064] <Variation 4> Fig. 11 is an enlarged cross-sectional view showing the configuration of an embedding member 130 and its surroundings according to Modification 4 of the embodiment, and Fig. 12 is a plan view showing an example of the configuration of the embedding member 130 according to Modification 4 of the embodiment as viewed from above. As shown in Fig. 12, in Modification 4, the second portion 132b is bent in plan view.

[0065] This allows the charged particles in the plasma to be effectively deactivated by colliding with the wall surface of the second flow path 132 when the plasma is generated above the first surface 110a and the charged particles enter the first flow path 112.

[0066] Furthermore, in variant 4, the overall length of the flow paths can be made even longer compared to when the first flow path 112 and the second flow path 132 are positioned in a straight line from the first surface 110a of the ceramic substrate 110 to the underside of the base plate 120.

[0067] This allows for the charged particles in the plasma to be effectively deactivated midway through the longer flow path when the plasma is generated above the first surface 110a and the charged particles in the plasma enter the first flow path 112.

[0068] In this manner, in the fourth modification, the second portion 132b has a structure that is further bent, and therefore, the occurrence of abnormal discharge in the first flow path 112 and the second flow path 132 can be effectively suppressed.

[0069] <Variation 5> Figure 13 is an enlarged cross-sectional view showing the configuration of the embedded member 130 and its surrounding area according to the fifth embodiment, and Figure 14 is a plan view showing an example of the configuration of the embedded member 130 according to the fifth embodiment viewed from above.

[0070] 13, in Modification 5, the second portion 132b is bent in a side view. In addition, in Modification 5, the second portion 132b has a portion through which the medium flows in a direction away from the first surface 110a (downward in FIG. 13).

[0071] This allows the charged particles in the plasma to be effectively deactivated when the plasma is generated above the first surface 110a and the charged particles enter the first flow path 112 by colliding with the wall surface of the second flow path.

[0072] Furthermore, in variant 5, the overall length of the flow paths can be made even longer compared to when the first flow path 112 and the second flow path 132 are positioned in a straight line from the first surface 110a of the ceramic substrate 110 to the underside of the base plate 120.

[0073] This allows for the charged particles in the plasma to be effectively deactivated midway through the longer flow path when the plasma is generated above the first surface 110a and the charged particles in the plasma enter the first flow path 112.

[0074] In this way, in the fifth modification, the occurrence of abnormal discharge in the first flow path 112 and the second flow path 132 can be effectively suppressed by causing the medium to flow in a direction away from the first surface 110a.

[0075] The sample holder 100 according to the embodiment includes a ceramic substrate 110, a base plate 120, and an embedding member 130. The ceramic substrate 110 has a first surface 110a on which a workpiece is placed, a second surface 110b opposite the first surface 110a, and a first flow path 112 penetrating between the first surface 110a and the second surface 110b. The base plate 120 is bonded to the second surface 110b of the ceramic substrate 110 and has a through-hole 122 at a position corresponding to at least the first flow path 112. The embedding member 130 has a porous body 131 at the end of the through-hole 122 facing the first flow path 112, and a second flow path 132 communicating with the first flow path 112 via the porous body 131. The second flow path 132 has a first portion 132a that is perpendicular to the first surface 110a and a second portion 132b that intersects with the first portion 132a, thereby making it possible to suppress the occurrence of abnormal discharge in the first flow path 112 and the second flow path 132.

[0076] Furthermore, in the sample holder 100 according to this embodiment, the second portion 132b is parallel to the first surface 110a, which allows the embedding member 130 to be formed easily.

[0077] Furthermore, in the sample holder 100 according to the embodiment, the second flow path 132 has a plurality of second portions 132b, which makes it possible to effectively suppress the occurrence of abnormal discharge in the first flow path 112 and the second flow path 132.

[0078] Furthermore, in the sample holder 100 according to the embodiment, the first flow path 112 and the first portion 132a of the second flow path 132 are positioned so as not to overlap each other in a plan view, thereby effectively suppressing the occurrence of abnormal discharge in the first flow path 112 and the second flow path 132.

[0079] Furthermore, in the sample holder 100 according to this embodiment, the second portion 132b is bent in plan view, which makes it possible to effectively suppress the occurrence of abnormal discharge in the first flow path 112 and the second flow path 132.

[0080] Furthermore, in the sample holder 100 according to the embodiment, the second portion 132b has a portion through which the medium flows in a direction away from the first surface 110a, thereby effectively suppressing the occurrence of abnormal discharge in the first flow path 112 and the second flow path 132.

[0081] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and various modifications are possible without departing from the spirit of the present invention. For example, in the above embodiments, an example in which the porous body 131 is provided in the embedding member 130 has been shown, but the present disclosure is not limited to such an example, and the porous body 131 may be provided in the ceramic substrate 110.

[0082] Further advantages and other aspects may readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. [Explanation of symbols]

[0083] 100 Sample holder 110 Ceramic substrate 110a 1st page 110b 2nd side 112 First Channel 120 base plate 122 Through hole 130 Embedded parts 131 Porous materials 132 Second Channel 132a Part 1 132b Part 2

Claims

1. A ceramic substrate; A base plate and an embedding member; the ceramic substrate has a first surface on which a workpiece is placed, a second surface opposite to the first surface, and a first flow path penetrating between the first surface and the second surface; the base plate is bonded to the second surface of the ceramic substrate and has a through hole at a position corresponding to at least the first flow path; the embedding member has a porous body at an end of the through hole on the first flow path side, and a second flow path communicating with the first flow path via the porous body, The second flow path is a first portion extending in a first direction perpendicular to the first surface; a second portion communicating with the first portion and extending in a second direction bent with respect to the first direction; Sample holder.

2. The second portion is parallel to the first surface.

2. The sample holder according to claim 1.

3. The second flow path has a plurality of the second portions.

3. The sample holder according to claim 1 or 2.

4. The first flow path and the first portion of the second flow path are positioned so as not to overlap each other in a plan view. The sample holder according to any one of claims 1 to 3.

5. The second portion is bent in a plan view. The sample holder according to any one of claims 1 to 4.

6. The second portion has a portion through which a medium flows in a direction away from the first surface. The sample holder according to any one of claims 1 to 5.

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