Retaining member

Abstract

The present invention provides a retaining member and a method for manufacturing the retaining member that improve connection reliability at the interface between the conductor layer and the connecting via. [Solution] The retaining member 10 of the present disclosure comprises a first insulating portion 71 made of an insulating material, a second insulating portion 72 made of an insulating material, conductor layers 81, 82, CL made of a conductive material, and a via portion 23 made of a conductive material, which is arranged in a through hole 74 that penetrates the second insulating portion 72 in a first direction (vertical direction or Z-axis direction). The conductor layers 81, 82, CL have a first conductor layer 81 formed between the first insulating portion 71 and the second insulating portion 72, and the via portion 23 has a via conductor 90 arranged in the through hole 74 and an intermediate conductor 91 connecting the first conductor layer 81 and the via conductor 90, wherein the intermediate conductor 91 is connected to the first conductor layer 81 by biting into it in a shape that protrudes toward the first insulating portion 71 side.

Description

Technical Field

[0001] The present disclosure relates to a holding member and a method for manufacturing the holding member.

Background Art

[0002] Conventionally, as a holding device that is part of a semiconductor manufacturing apparatus and holds an object such as a wafer, a ceramic device described in Japanese Unexamined Patent Application Publication No. 2023-175100 (hereinafter referred to as Patent Document 1) is known. This ceramic device includes a ceramic member having a main body portion formed of ceramics and internal electrodes. The ceramic device 1 is used, for example, as part of a semiconductor manufacturing apparatus. The ceramic device 1 is installed in a chamber of a semiconductor manufacturing apparatus, and a wafer is placed on the first surface of the ceramic member.

[0003] Patent Document 1 describes that, as a method for manufacturing a ceramic member, an unsintered conductive layer that becomes an internal electrode and a via for connection is formed on a plurality of green sheets after firing. By laminating the plurality of green sheets and firing them in a state where the unsintered conductive layers are in contact with each other, a ceramic member in which a via for connection is connected to an internal electrode can be formed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In recent years, in the semiconductor manufacturing process, there are times when stability in power supply to the holding device itself is required. Therefore, further improvement in connection reliability at the interface between the internal electrode and the via for connection is required.

Means for Solving the Problems

[0006] The retaining member of this disclosure comprises a first insulating portion made of an insulating material, a second insulating portion made of the insulating material, a conductor layer made of a conductive material, and a via portion made of a conductive material disposed in a through hole penetrating the second insulating portion in a first direction, wherein the conductor layer has a first conductor layer formed between the first insulating portion and the second insulating portion, and the via portion has a via conductor disposed in the through hole and an intermediate conductor connecting the first conductor layer and the via conductor, wherein the intermediate conductor is connected to the first conductor layer by biting into it in a shape that protrudes toward the first insulating portion.

[0007] A method for manufacturing a retaining member according to the present disclosure comprises a first insulating portion made of an insulating material, a second insulating portion made of the insulating material, a conductive layer made of a conductive material, and a via portion made of a conductive material disposed in a through hole penetrating the second insulating portion in a first direction, wherein the conductive layer is a first conductive layer formed between the first insulating portion and the second insulating portion, the method for manufacturing a retaining member comprising: a first printing step of printing a first conductive paste onto the first surface of a first green sheet which will become the first insulating portion to form the first conductive layer before firing, and a second insulating portion which will become the second insulating portion and has a second surface A method for manufacturing a retaining member, comprising: a second printing step of forming through holes that penetrate two green sheets and filling the through holes with a second conductive paste to form the via portion before firing; a lamination step of arranging the first and second surfaces facing each other and stacking the first and second green sheets in the first direction to obtain a green sheet laminate; and a firing step of firing the green sheet laminate obtained in the lamination step, wherein in the second printing step, the second conductive paste is formed in a form that protrudes from the second surface. [Effects of the Invention]

[0008] According to this disclosure, it is possible to provide a retaining member with improved connection reliability at the interface between a conductor layer and a connecting via, and a method for manufacturing the retaining member. [Brief explanation of the drawing]

[0009] [Figure 1]Figure 1 is a schematic perspective view showing the external configuration of the electrostatic chuck according to Embodiment 1. [Figure 2] Figure 2 is a schematic cross-sectional view showing the internal structure of an electrostatic chuck. [Figure 3] Figure 3 is a cross-sectional view showing an enlarged portion of the retaining member in Figure 2. [Figure 4] Figure 4 is a magnified view of the via section and a portion of the conductor layer shown in Figure 3. [Figure 5] Figure 5 is an explanatory diagram showing a method for manufacturing a retaining member according to Embodiment 1. [Modes for carrying out the invention]

[0010] [Description of Embodiments in this Disclosure] First, embodiments of this disclosure will be listed and described. (1) The retaining member of the present disclosure comprises: a first insulating portion made of an insulating material; a second insulating portion made of the insulating material; a conductor layer made of a conductive material; and a via portion made of a conductive material disposed in a through hole penetrating the second insulating portion in a first direction, wherein the conductor layer has a first conductor layer formed between the first insulating portion and the second insulating portion; the via portion has a via conductor disposed in the through hole and an intermediate conductor connecting the first conductor layer and the via conductor, the intermediate conductor being connected to the first conductor layer by biting into it in a shape that protrudes toward the first insulating portion side.

[0011] With this configuration, an interface is formed between the first conductor layer formed between the first and second insulating parts, and the intermediate conductor connecting the first conductor layer and the via conductor, with the interface protruding towards the first insulating part. For example, in the case of an interface with a curved, raised shape, the contact area between the first conductor layer and the intermediate conductor increases compared to a linear interface. This improves the adhesion between the via portion and the first conductor layer, and reduces the electrical resistance between the via portion and the first conductor layer. Therefore, the reliability of the connection between the via portion and the first conductor layer can be ensured against shrinkage during firing. In this specification, a linear shape refers to a shape that is approximately linear and substantially identical to a linear shape.

[0012] (2) In the holding member described in (1), the intermediate conductor has a first via intermediate conductor portion connected to the via conductor and a second via intermediate conductor portion formed on the outer circumference of the first via intermediate conductor portion and not connected to the via conductor, the first conductor layer has a first conductor layer portion connected to the first via intermediate conductor portion and a second first conductor layer portion connected to the second via intermediate conductor portion, the first portion is composed of the first via intermediate conductor portion and the first conductor layer portion, the second portion is composed of the second via intermediate conductor portion and the second first conductor layer portion, the thickness of the first via intermediate conductor portion in the first direction is preferably thicker than that of the second via intermediate conductor portion, and the thickness of the second portion in the first direction is preferably thicker as it approaches the first portion.

[0013] With this configuration, the thickness of the intermediate conductor in the first direction is greatest in the first portion of the via intermediate conductor, and even when the thickness of the intermediate conductor and the first conductor layer are combined, the thickness of the first portion is also greatest. This makes it easier to relieve the stress generated by shrinkage during firing in the first portion, and makes it easier to ensure good adhesion between the via portion and the conductor layer. In addition, it is possible to prevent cracking of the intermediate conductor due to shrinkage during firing.

[0014] (3) In the holding member described in (2), the conductor layer further comprises the insulating material, the via portion further comprises the insulating material, the first conductor layer has a third conductor layer portion formed on the outer periphery of the second portion of the first conductor layer, and it is preferable that the content of the insulating material per unit volume of the first portion and the content of the insulating material per unit volume of the second portion are greater than the content of the insulating material per unit volume of the third portion of the first conductor layer, and that the thickness of each of the first portion and the second portion in the first direction is greater than the thickness of the third portion of the first conductor layer.

[0015] With such a configuration, since each of the first part and the second part has a higher content per unit volume of the insulating material, it is more likely to generate heat compared to the third part of the first conductor layer. However, since each of the first part and the second part is thicker than the third part of the first conductor layer, the local heat generation amount in each of the first part and the second part can be reduced.

[0016] (4) In the holding member according to (3), it is preferable that the content of the insulating material per unit volume of the via portion is greater than the content of the insulating material per unit volume of the first conductor layer.

[0017] With such a configuration, since the via portion has a higher content per unit volume of the insulating material, it is more likely to generate heat locally compared to the first conductor layer. However, the intermediate conductor in the via portion protrudes toward the first insulating portion side and bites into the first conductor layer for connection, so the contact area between the first conductor layer and the intermediate conductor increases, and thus the local heat generation in the via portion can be alleviated.

[0018] (5) In the holding member according to any one of (1) to (4), it is preferable that the insulating material is alumina.

[0019] Alumina can be used as the insulating material.

[0020] (6) In the holding member according to any one of (1) to (5), it includes a third insulating portion made of the insulating material, the conductor layer has a second conductor layer formed between the second insulating portion and the third insulating portion, and it is preferable that the second conductor layer has a via connection portion that protrudes toward the first insulating portion side and bites into the via portion for connection.

[0021] With such a configuration, an interface that protrudes toward the first insulating portion is formed between the via portion and the via connection portion. For example, in the case of an interface that bulges in a curved surface shape, the contact area between the via portion and the via connection portion increases as compared with a linear interface. As a result, the adhesion between the via portion and the second conductor layer is improved. In addition, the electrical resistance between the via portion and the second conductor layer can be reduced. Therefore, the connection reliability between the via portion and the second conductor layer can be ensured against shrinkage during firing.

[0022] (7) The method for manufacturing a holding member of the present disclosure includes a first insulating portion made of an insulating material, a second insulating portion made of the insulating material, a conductor layer made of a conductive material, and a via portion made of a conductive material disposed in a through hole that penetrates the second insulating portion in a first direction. The conductor layer has a first conductor layer formed between the first insulating portion and the second insulating portion. The method for manufacturing a holding member includes a first printing step of printing a first conductive paste on a first surface of a first green sheet that becomes the first insulating portion to form the first conductor layer before firing, a second printing step of forming a through hole that penetrates a second green sheet that becomes the second insulating portion and has a second surface, and filling the through hole with a second conductive paste to form the via portion before firing, a lamination step of disposing the first surface and the second surface to face each other and laminating the first green sheet and the second green sheet in the first direction to obtain a green sheet laminate, and a firing step of firing the green sheet laminate obtained by the lamination step. In the second printing step, the second conductive paste is formed in a form that protrudes from the second surface.

[0023] According to such a method for manufacturing a holding member, since the second conductive paste is formed in a form that protrudes toward the first insulating portion side from the second surface, the via portion before firing easily bites into the first conductor layer side, and the connection area between the intermediate conductor and the first conductor layer increases. As a result, the adhesion between the via portion and the first conductor layer is improved, and the connection reliability between the via portion and the first conductor layer can be ensured.

[0024] [Details of Embodiments of the Present Disclosure] Specific examples of embodiments of this disclosure will be described with reference to Figures 1 to 5. This disclosure is not limited to these examples, but is intended to include all modifications within the meaning and scope of the claims, as indicated by the claims. In the following description, for multiple identical components, only some components may be reference-labeled, while others may be omitted. In each drawing, some components may be exaggerated or simplified for illustrative purposes. Also, the dimensional ratios of each part may differ between drawings. In this specification, the configuration of the retaining member and retaining device is described with the positive Z-axis direction as upward, the negative Z-axis direction as downward, and the XY plane direction as horizontal, as shown in Figure 1; however, the actual usage of the retaining member and retaining device may involve different arrangements. Here, the Z-axis is the axial axis of the retaining device 1 (up and down direction in Figure 1), and is an example of the "first direction" in this disclosure. The X-axis and Y-axis are the radial axes of the retaining device 1. Furthermore, the term "orthogonal" in this specification includes not only strictly orthogonal connections, but also connections that are approximately orthogonal within the scope of the effects and benefits described in this embodiment. Additionally, terms such as "first," "second," and "third" in this specification are used solely to distinguish between objects and do not imply any ranking or ranking.

[0025] <Electrostatic Chuck 1> The holding device 1 equipped with the holding member 10 of this disclosure is an electrostatic chuck capable of adsorbing and holding an object such as a semiconductor wafer or a glass substrate (hereinafter referred to as "wafer W") by electrostatic attraction. The holding device 1 is attached, for example, to a processing chamber of a semiconductor manufacturing apparatus (not shown) and used to perform various processes (film deposition, etching, etc.) on the wafer W using plasma.

[0026] As shown in Figure 1, the holding device 1 comprises a holding member 10, a base member 20, and a joint 30. In the vertical direction, the holding member 10 and the base member 20 are thermally joined by the joint 30.

[0027] <Joint part 30> The joint portion 30 is made of an adhesive such as a silicone resin, fluororesin, acrylic resin, or epoxy resin. The thickness of the joint portion 30 is, for example, about 0.1 mm to 1.5 mm. As shown in Figure 2, a terminal hole 31 is formed in this joint portion 30, which penetrates vertically and communicates with the terminal hole 22 described later. The upper end of the terminal hole 31 communicates with the terminal hole 15 formed in the holding member 10 (see Figure 3).

[0028] <Base member 20> As shown in Figures 1 and 2, the base member 20 is a disc-shaped member overall, and can be formed into a shape with, for example, a diameter of about 340 mm and a thickness of about 35 mm. The main material forming the base member 20 is a conductive material such as titanium (Ti), copper (Cu), aluminum (Al), or alloys thereof. Here, "main material forming the base member" refers to the main component, meaning the material that has the highest content (weight percentage or volume percentage) (the same applies hereinafter). As shown in Figure 2, the upper surface 20A of the base member 20 is positioned on the side of the retaining member 10. The upper surface 20A of the base member 20 is joined to the lower surface 10B of the retaining member 10, which will be described later, by a joint 30. The lower surface 20B of the base member 20 is positioned on the opposite side from the upper surface 20A. The lower surface 20B of the base member 20 is positioned on the underside of the base member 20.

[0029] A refrigerant channel 21 (cooling mechanism) is provided inside the base member 20. The refrigerant channel 21 is connected to a refrigerant circulation device (not shown). The refrigerant circulation device is configured to circulate a refrigerant such as a fluorine-based inert liquid or water through the refrigerant channel 21. When refrigerant flows through the refrigerant channel 21, the base member 20 is cooled, and the holding member 10 is cooled by heat transfer (heat dissipation) between the base member 20 and the holding member 10 via the joint 30, thereby cooling the wafer W held by the holding surface 10A of the holding member 10, which will be described later. This allows the temperature of the wafer W to be controlled.

[0030] The base member 20 has a terminal hole 22 that penetrates vertically between the upper surface 20A and the lower surface 20B. The terminal hole 22 communicates with the terminal hole 31 and forms an internal space. The terminal hole 31 and the terminal hole 22 have power supply terminals 26 inside.

[0031] <Holding member 10> As shown in Figure 1, the holding member 10 is generally disc-shaped when viewed in the Z-axis direction, and can be formed into a plate shape with, for example, a diameter of about 300 mm and a thickness of about 20 mm. As shown in Figures 2 and 3, the holding member 10 comprises an insulating part 11, internal electrodes 40, 50, and 60 arranged inside the insulating part 11, a power supply terminal 26 arranged in the insulating part 11 and capable of supplying current to the internal electrodes 40, 50, and 60, a pad part 25 exposed from the lower surface 10B of the insulating part 11 and connected to the power supply terminal 26, and a via part 23 and connecting electrode 24 arranged inside the insulating part 11, extending in the vertical direction and connecting the pad part 25 and the internal electrodes 40, 50, and 60 in a way that allows current to pass between them.

[0032] The insulating portion 11 is an insulating substrate. The material mainly forming the insulating portion 11 is a ceramic made of an insulating material. For example, the insulating portion 11 is formed of a ceramic mainly composed of aluminum nitride (AlN), yttria (Y2O3), silicon carbide (SiC), alumina (Al2O3), or a composite material of alumina and silicon carbide.

[0033] In Figure 1, the Z-axis direction is defined as the vertical direction (an example of the first direction). The upper surface of the holding member 10 is a holding surface 10A that is perpendicular to the vertical direction. The holding surface 10A functions as a surface for holding the wafer W. The lower surface 10B of the holding member 10, which is located on the opposite side of the holding surface 10A, is joined to the base member 20 via a joint 30.

[0034] As shown in Figure 2, the retaining surface 10A of the retaining member 10 has an uneven shape. Specifically, the retaining surface 10A comprises an annular seal band 12 formed near its outer edge and a plurality of protrusions (mesas) 13 independently provided inside it. The seal band 12 and the protrusions 13 are each provided in a form that rises upward from the flat reference surface 14.

[0035] The retaining surface 10A is composed of the upper surface of the seal band 12 and the upper surface of the protrusion 13. The reference surface 14 is positioned below the retaining surface 10A and above the internal electrode 40. A space SP is formed between the semiconductor wafer W held by the retaining surface 10A and the reference surface 14. The space SP is formed inside the seal band 12.

[0036] When processes such as film deposition are performed in semiconductor manufacturing equipment, helium gas for temperature control is supplied to the space SP from the outside through gas holes (not shown) formed in the holding member 10. By interposing helium gas between the holding member 10 and the wafer W, the thermal resistance between them is adjusted, thereby maintaining the temperature of the wafer W at an appropriate temperature. Note that the gas supplied to the space SP may be a different type of gas than helium gas.

[0037] Inside the holding member 10 are internal electrodes 40, 50, and 60 formed from a conductive material (for example, tungsten, molybdenum, platinum, etc.). In this embodiment, internal electrode 40 is a chuck electrode. In this embodiment, internal electrode 50 is a heater electrode. In this embodiment, internal electrode 60 is a driver electrode. In this embodiment, internal electrodes 40, 50, and 60 are exemplified as one chuck electrode, one heater electrode, and one driver electrode, respectively. However, an electrode other than the chuck electrode may be used as internal electrode 40, an electrode other than the heater electrode may be used as internal electrode 50, and an electrode other than the driver electrode may be used as internal electrode 60. Furthermore, in this embodiment, internal electrodes 40, 50, and 60 are exemplified as one chuck electrode, one heater electrode, and one driver electrode, respectively. However, multiple combinations of chuck electrodes, heater electrodes, driver electrodes, and other electrodes may be used for each of the internal electrodes 40, 50, and 60.

[0038] The internal electrodes 40, 50, 60, the pad portion 25, the via portion 23, and the connecting electrode 24 are made of a conductive material containing tungsten, molybdenum, etc. The holding member 10 has a terminal hole 15 as shown in Figure 3. The terminal hole 15 communicates with the terminal hole 31. The pad portion 25 is formed at the upper end of the terminal hole 15. Power supply terminals 26 are housed inside the terminal holes 15 and 31. The pad portion 25 is connected to the upper end of the power supply terminal 26. The lower end of the power supply terminal 26 is connected to a power source (not shown). The conductive materials of the internal electrodes 40, 50, 60, the pad portion 25, and the connecting electrode 24 may be the same material and have different content ratios.

[0039] The internal electrodes 40, 50, and 60 extend, for example, in a horizontal direction perpendicular to the vertical direction. The internal electrodes 40, 50, and 60 are electrically connected to a power supply terminal 26 via a via portion 23, a connecting electrode 24, and a pad portion 25. Power is supplied to the internal electrodes 40, 50, and 60 from an external power source (not shown) via the power supply terminal 26. When power is supplied from the external power source to the internal electrodes 40, 50, and 60, which function as chuck electrodes, heater electrodes, or driver electrodes, via the power supply terminal 26, an electrostatic attraction is generated, and the wafer W is attracted and held on the holding surface 10A by this electrostatic attraction. The pad portion 25 and the connecting electrode 24 form, for example, layers extending in a horizontal direction perpendicular to the vertical direction. The via portion 23 has, for example, a columnar shape perpendicular to the holding surface 10A.

[0040] As shown in Figure 3, the via portions 23 and connecting electrodes 24 are arranged alternately and stacked in the vertical direction. Furthermore, each of the multiple via portions 23 and multiple connecting electrodes 24 positioned between the internal electrodes 50 and 60 in the vertical direction, and each of the multiple via portions 23 and multiple connecting electrodes 24 positioned between the internal electrodes 60 and the pad portion 25 (or power supply terminal 26), are offset in the horizontal direction perpendicular to the vertical direction.

[0041] Figure 3 shows an arrangement in which one via portion 23, two via portions 23, and one via portion 23 are alternately arranged between the internal electrode 50 and the internal electrode 60 in the vertical direction, but the number of via portions 23 is not limited to those shown. Figure 3 also shows an arrangement in which two via portions 23, one via portion 23, and two via portions 23 are alternately arranged between the internal electrode 60 and the pad portion 25 (or power supply terminal 26) in the vertical direction, but the number of via portions 23 is not limited to those shown. In Figure 3, there are two connecting electrodes 24 arranged between the internal electrode 50 and the internal electrode 60, but the number of connecting electrodes 24 is not limited to those shown. In Figure 3, there are two connecting electrodes 24 arranged between the internal electrode 60 and the pad portion 25 (or power supply terminal 26), but the number of connecting electrodes 24 is not limited to those shown.

[0042] Figure 4 is an enlarged cross-sectional view of a portion of Figure 3, in which, from top to bottom, the first insulating portion 71, the first conductor layer 81, the second insulating portion 72, the second conductor layer 82, and the third insulating portion 73 are stacked. The first conductor layer 81, which is formed between the first insulating portion 71 and the second insulating portion 72, and the second conductor layer 82, which is formed between the second insulating portion 72 and the third insulating portion 73, constitute a part of the conductor layer CL made of a conductive material. Here, the first conductor layer 81 and the second conductor layer 82 correspond to the conductor layer CL of this disclosure.

[0043] The first insulating portion 71, the second insulating portion 72, and the third insulating portion 73 constitute a part of the insulating portion 11. Here, the first insulating portion 71, the second insulating portion 72, and the third insulating portion 73 form layers that extend horizontally, for example, perpendicular to the vertical direction. The first conductor layer 81 and the second conductor layer 82 constitute a part of the connecting electrode 24. The first conductor layer 81 and the second conductor layer 82 form layers that extend horizontally, for example, perpendicular to the vertical direction. The first conductor layer 81 and the second conductor layer 82 are connected via a via portion 23.

[0044] Furthermore, the first conductor layer 81, the via portion 23, and the second conductor layer 82 form conductive paths with each other and are electrically connected. These conductive paths form part of the conductive paths that electrically connect the power supply terminal 26 and the internal electrodes 40, 50, and 60. For example, the second conductor layer 82 is electrically connected to the first conductor layer 81 via the via portion 23.

[0045] The via portion 23 is located in the same layer as the second insulating portion 72. The second insulating portion 72 has a through hole 74 that penetrates in the vertical direction. The via portion 23 is formed by filling the through hole 74 with a conductive material. The conductive material of the internal electrodes 40, 50, 60, the pad portion 25, and the connecting electrode 24 and the conductive material filled in the via portion 23 may be the same conductive material, or they may be different conductive materials.

[0046] The via portion 23 includes a via conductor 90 positioned in the through hole 74 and an intermediate conductor 91 connecting the first conductor layer 81 and the via conductor 90. In the vertical direction, the intermediate conductor 91 is connected to the first conductor layer 81 by biting into it with a shape that protrudes toward the first insulating portion 71. Thus, an interface K1 is formed in which the intermediate conductor 91 is connected to the first conductor layer 81 by biting into it with a shape that protrudes toward the first insulating portion 71. Therefore, as shown in Figure 4, the interface K1 between the intermediate conductor 91 and the first conductor layer 81 of the via portion 23 is formed in a curved shape that rises upward and widens horizontally.

[0047] At the curved interface K1, for example, the contact area between the via portion 23 and the first conductor layer 81 increases compared to when a planar interface is formed. This improves the adhesion between the via portion 23 and the first conductor layer 81. Furthermore, the increased contact area reduces the electrical resistance between the via portion 23 and the first conductor layer 81. Therefore, improved adhesion helps maintain the contact state against shrinkage during firing, keeping the contact area constant and thus ensuring the reliability of the connection between the via portion 23 and the first conductor layer 81.

[0048] The intermediate conductor 91 has a first via intermediate conductor portion 95 connected to the via conductor 90 in the vertical direction, and a second via intermediate conductor portion 96 formed on the outer circumference of the first via intermediate conductor portion 95 and not connected to the via conductor 90. The second via intermediate conductor portion 96 is formed on the outer circumference of the first via intermediate conductor portion 95 in the horizontal direction. When viewed from above, the second via intermediate conductor portion 96 is formed in an annular shape surrounding the first via intermediate conductor portion 95. The first via intermediate conductor portion 95 is mainly connected to the via conductor 90. As shown in Figure 4, this first via intermediate conductor portion 95 has a greater thickness in the vertical direction than the second via intermediate conductor portion 96 which is not connected to the via conductor 90.

[0049] The first conductor layer 81 includes a first conductor layer portion 85 connected to the via intermediate conductor portion 95 in the vertical direction, a second conductor layer portion 86 connected to the via intermediate conductor portion 2 96, and a third conductor layer portion 87 formed on the outer periphery of the second conductor layer portion 86. The second conductor layer portion 86 is formed on the outer periphery of the first conductor layer portion 85 in the horizontal direction.

[0050] The third portion 87 of the first conductor layer is formed on the outer periphery of the second portion 86 of the first conductor layer in the horizontal direction. The third portion 87 of the first conductor layer is not connected to the intermediate conductor 91 in the vertical direction.

[0051] The first part 110 is composed of the via intermediate conductor first part 95 and the first conductor layer first part 85. The second part 120 is composed of the via intermediate conductor second part 96 and the first conductor layer second part 86. As shown in Figure 4, the first conductor layer third part 87 is not connected to the intermediate conductor 91, so its vertical thickness is smaller than that of the first part 110, which has the first conductor layer first part 85 that is mainly connected to the intermediate conductor 91. Also, since the first conductor layer third part 87 is not connected to the intermediate conductor 91, its vertical thickness is smaller than that of the second part 120, which has the first conductor layer second part 86 that is connected to the intermediate conductor 91.

[0052] Figure 4 illustrates the first region R1, the second region R2, and the third region R3. The first region R1 is the region containing the first part 110. The second region R2 is the region containing the second part 120. The third region R3 is the region containing the third part 87 of the first conductor layer.

[0053] The vertical thickness of the first via intermediate conductor portion 95 is greater than that of the second via intermediate conductor portion 96. The vertical thickness of the second portion 120 increases as it approaches the first portion 110. With this configuration, the first-direction thickness of the intermediate conductor 91, which has the first via intermediate conductor portion 95 and the second via intermediate conductor portion 96, is greatest in the first via intermediate conductor portion 95. This makes it easier to relieve stress generated by shrinkage during firing in the first portion 110, and makes it easier to ensure good adhesion between the via portion 23 and the first conductor layer 81. Furthermore, it is possible to prevent cracking of the intermediate conductor 91 due to shrinkage during firing.

[0054] Each conductor layer 81, 82 and via portion 23 further contains an insulating material that constitutes the insulating portion 11. The first conductor layer 81 is in close contact with the upper end of the via portion 23, and the second conductor layer 82 is in close contact with the lower end of the via portion 23 via this insulating material. Here, for example, the insulating material is a ceramic such as alumina (Al2O3). It is preferable that the content of insulating material per unit volume of the conductor layer CL is less than the content of insulating material per unit volume of the via portion 23. More specifically, in this case, it is preferable that the content of insulating material per unit volume of the first conductor layer 81 is less than the content of insulating material per unit volume of the via portion 23. In this case, it is preferable that the content of insulating material per unit volume of the second conductor layer 82 is less than the content of insulating material per unit volume of the via portion 23. The first conductor layer 81 and the second conductor layer 82 may have the same or different content of insulating material per unit volume, but it is preferable that the content of insulating material per unit volume is less than that of the via portion 23.

[0055] Therefore, since the via portion 23 has a higher content of insulating material per unit volume compared to each conductor layer 81 and 82, the adhesion with the second insulating portion 72 is improved. Because the via portion 23 has a higher content of insulating material per unit volume, it is more prone to generating heat than the first conductor layer 81. However, the intermediate conductor 91 of the via portion 23 is connected to the first conductor layer 81 by protruding toward the first insulating portion 71 and biting into it, forming an interface K1. Therefore, in this embodiment, the contact area between the first conductor layer 81 and the intermediate conductor 91 is increased by the curved interface K1, which can mitigate localized heat generation in the via portion 23.

[0056] When the via portion 23 contains more insulating material per unit volume than the conductor layers 81 and 82, the region in Figure 4 that includes the first portion 110 and the second portion 120 is the region that includes the via portion 23. Therefore, the region in Figure 4 that includes the first portion 110 and the second portion 120 contains more insulating material per unit volume than the third portion 87 of the first conductor layer in Figure 4 that does not include the via portion 23. Thus, the insulating material content per unit volume of the first portion 110 and the insulating material content per unit volume of the second portion 120 are both greater than the insulating material content per unit volume of the third portion 87 of the first conductor layer.

[0057] The region in Figure 4 that includes the first portion 110 and the second portion 120 is thicker in the vertical direction than the third portion 87 of the first conductor layer in Figure 4, which does not include the via portion 23, because it has the thickness of the intermediate conductor 91 in the vertical direction. Therefore, the thickness of each of the first portion 110 and the second portion 120 is thicker than the thickness of the third portion 87 of the first conductor layer.

[0058] The first portion 110 and the second portion 120 are more prone to generating heat because they contain a higher amount of insulating material per unit volume than the third portion 87 of the first conductor layer. However, since the first portion 110 and the second portion 120 are thicker than the third portion 87 of the first conductor layer, and the via portion (intermediate conductor 91) penetrates the first conductor layer 81 at interface K1, increasing the contact area, localized heat generation in these portions can be reduced.

[0059] As shown in Figure 4, the second conductor layer 82 has a via connection portion 83 that connects to the lower end of the via portion 23. The via connection portion 83 is connected to the via portion 23 by biting into it in a shape that protrudes toward the first insulating portion 71. Therefore, an interface K2 is formed between the via portion 23 and the via connection portion 83, with a shape that protrudes toward the first insulating portion 71. As shown in Figure 4, the interface K2 formed between the via portion 23 and the via connection portion 83 is formed in a curved shape that rises upward.

[0060] At the interface K2 of the via connection portion 83, the contact area between the via portion 23 and the via connection portion 83 is increased compared to a planar interface. This improves the adhesion between the via portion 23 and the second conductor layer 82. Furthermore, the electrical resistance between the via portion 23 and the second conductor layer 82 can be reduced. Therefore, the reliability of the connection between the via portion 23 and the second conductor layer 82 can be ensured against shrinkage during firing.

[0061] <Method for manufacturing a retaining member> The above describes the configuration of the holding device 1 of Embodiment 1, and below, an example of a method for manufacturing the holding member 10 will be described with reference to Figure 5. The method for manufacturing the holding member 10 of this embodiment broadly includes a first printing step for forming the first conductive layer 81(L) before firing, a second printing step for forming the via portion 23(L) before firing, a lamination step, and a firing step.

[0062] The manufacturing method for the retaining member 10 is an application of a sheet lamination method using a green sheet (ceramic green sheet). In Figures 5(A) and 5(B), the lower side of the figure corresponds to the lower surface 10B of the retaining member 10, and the upper side of the figure corresponds to the retaining surface 10A of the retaining member 10.

[0063] First, multiple green sheets of the same shape and composition (for example, thickness: 200 μm) made of ceramics are prepared. As shown in Figure 5, these multiple green sheets include a first green sheet 171, a second green sheet 172, and a third green sheet, which will be described later. The first green sheet 171, the second green sheet 172, and the third green sheet ultimately constitute an unfired green sheet laminate L, which will be described later. The second green sheet 172(L) may also be constructed by laminating multiple thinner second green sheets 172(L)1, as shown in Figure 5. The same applies to the first green sheet 171(L) and the third green sheet.

[0064] The first green sheet 171(L) has an upper surface 171A and a lower surface 171B located on the opposite side of the upper surface 171A. The second green sheet 172(L) has an upper surface 172A and a lower surface located on the opposite side of the upper surface 172A. The first green sheet 171(L) becomes the first insulating part 71 after firing, the second green sheets 172(L) and 172(L)1 become the second insulating part 72 after firing, and the third green sheet becomes the third insulating part 73 after firing.

[0065] The first printing step is a step in which the first conductive layer 81(L) is formed before firing. In the first printing step, as shown in Figure 5(A), a first conductive paste is applied to the lower surface 171B of the first green sheet 171(L). The first conductive paste is a paste made of a conductive material such as tungsten paste, and may be the same material and content as the second conductive paste described later, or it may be a different material. In this embodiment, as shown in Figure 4, the first conductive layer 81 is formed in a state in which it is connected to the via conductor 90 via an intermediate conductor 91 having a predetermined thickness. The lower surface 171B corresponds to the first surface of this disclosure.

[0066] The second printing process is a process for forming the via portion 23(L) before firing. In the second printing process, as shown in Figure 5(A), the second conductive paste is filled into through holes 74(L) formed perpendicular to the upper surface 172A of the second green sheet 172(L), i.e., in the vertical direction. First, through holes 74(L) are formed that penetrate the second green sheet 172(L) in the vertical direction. These through holes 74(L) become through holes 74 after firing. Next, the second conductive paste is filled into these through holes 74(L). The second conductive paste is a paste made of a conductive material that is placed in the through holes 74(L) of the via portion 23(L). The second conductive paste is a paste made of a conductive material such as tungsten paste. The upper surface 172A corresponds to the second surface of this disclosure.

[0067] Figure 5(A) shows a part of the unbaked green sheet laminate L, which will be described later, before lamination. The via portion 23(L) formed in the second printing process before firing is formed such that a protruding portion 172C(L) protrudes from the upper surface 172A of the second green sheet 172(L) towards the first green sheet 171(L) (upwards in Figure 5(A)). Figure 5(B) shows the state after firing following the lamination process. The holding member 10 shown in Figure 5(B) has, in order from top to bottom in the vertical direction, a first insulating portion 71, a first conductor layer 81, and a second insulating portion 72. In Figure 5(B), the second conductor layer 82, which is laminated below the second insulating portion 72, and the third insulating portion 73 are omitted. The through hole 74 of the second insulating portion 72 is filled with a via conductor 90. An intermediate conductor 91 is formed at the upper end of the via conductor 90. In this way, the via portion 23 is formed in the same layer as the second insulating portion 72. Furthermore, the vertical interfaces between the multiple second green sheets 172(L)1 are integrated by sintering, and as shown in Figure 4, the second insulating portion 72 is formed with the multiple second green sheets 172(L)1 integrated.

[0068] In the lamination process, the first green sheet 171(L) and the second green sheet 172(L) are arranged so that the first surface 171B (bottom surface) and the second surface 172A (top surface) face each other, and the first green sheet 171(L) and the second green sheet 172(L) are laminated in the first direction (vertical direction or Z-axis direction) to obtain a green sheet laminate (L). Subsequently, the unfired green sheet laminate L is fired to form the insulating part 11, internal electrodes 40, 50, 60, pad part 25, via part 23, connecting electrode 24, etc. (firing process). The holding member 10 is formed by further polishing or other processes on the fired body. For example, a thermocompression bonding process may be added to the lamination process.

[0069] <Effects of Embodiment 1> As described above, the retaining member 10 of Embodiment 1 comprises a first insulating portion 71 made of an insulating material, a second insulating portion 72 made of an insulating material, conductive layers 81 and 82 made of a conductive material, and a via portion 23 made of a conductive material that is arranged in a through hole 74 that penetrates the second insulating portion 72 in a first direction (vertical direction or Z-axis direction). The conductive layers 81 and 82 have a first conductive layer 81 formed between the first insulating portion 71 and the second insulating portion 72, and the via portion 23 has a via conductor 90 arranged in the through hole 74 and an intermediate conductor 91 that connects the first conductive layer 81 and the via conductor 90. The intermediate conductor 91 is connected to the first conductive layer by biting into it in a shape that protrudes toward the first insulating portion 71 side.

[0070] With this configuration, an interface K1 is formed between the first conductor layer 81 formed between the first insulating portion 71 and the second insulating portion 72, and the intermediate conductor 91 connecting the first conductor layer 81 and the via conductor 90, with the interface K1 having a shape that protrudes toward the first insulating portion 71. For example, in the case of an interface K1 with a curved, raised shape, the contact area between the first conductor layer 81 and the intermediate conductor 91 increases compared to a linear interface. This improves the adhesion between the via portion 23 and the first conductor layer 81, and reduces the electrical resistance between the via portion 23 and the first conductor layer 81. Therefore, the reliability of the connection between the via portion 23 and the first conductor layer 81 can be ensured against shrinkage during firing. In this specification, a linear shape refers to a shape that is approximately linear and substantially identical to a linear shape.

[0071] In the holding member 10 of Embodiment 1, the intermediate conductor 91 has a via intermediate conductor first portion 95 connected to the via conductor 90, and a via intermediate conductor second portion 96 formed on the outer circumference of the via intermediate conductor first portion 95 and not connected to the via conductor 90. The first conductor layer 81 has a first conductor layer first portion 85 connected to the via intermediate conductor first portion 95, and a first conductor layer second portion 86 connected to the via intermediate conductor second portion 96. The via intermediate conductor first portion 95 and the first conductor layer first portion 85 constitute the first portion 110, and the via intermediate conductor second portion 96 and the first conductor layer second portion 86 constitute the second portion 120. Preferably, the thickness of the via intermediate conductor first portion 95 in a first direction (vertical direction or Z-axis direction) is thicker than that of the via intermediate conductor second portion 96, and the thickness of the second portion 120 in a first direction (vertical direction or Z-axis direction) becomes thicker as it approaches the first portion 110.

[0072] With this configuration, the thickness of the intermediate conductor 91 in the first direction (vertical or Z-axis direction) is thickest at the first via intermediate conductor portion 95, and the thickness of the first portion 110 is also the thickest when the intermediate conductor 91 and the first conductor layer 81 are combined. This makes it easier to relieve stress generated by shrinkage during firing at the first portion 110, and makes it easier to ensure good adhesion between the via portion 23 and the first conductor layer 81. In addition, it is possible to prevent cracking of the intermediate conductor 91 due to shrinkage during firing.

[0073] In the holding member 10 of Embodiment 1, the conductor layers 81 and 82 further contain an insulating material, the via portion 23 further contains an insulating material, the first conductor layer 81 has a first conductor layer third portion 87 formed on the outer periphery side of the first conductor layer second portion 86, the content of insulating material per unit volume of the first portion 110 and the content of insulating material per unit volume of the second portion 120 are each greater than the content of insulating material per unit volume of the first conductor layer third portion 87, and it is preferable that the thickness of each of the first portion 110 and the second portion 120 in the first direction is greater than the thickness of the first conductor layer third portion 87.

[0074] With this configuration, each of the first part 110 and the second part 120 has a higher content of insulating material per unit volume, and therefore generates more heat compared to the third part 87 of the first conductor layer. However, each of the first part 110 and the second part 120 is thicker than the third part 87 of the first conductor layer, so the amount of localized heat generated in each of the first part 110 and the second part 120 can be reduced.

[0075] In the holding member 10 of Embodiment 1, it is preferable that the content of insulating material per unit volume of the via portion 23 is greater than the content of insulating material per unit volume of the first conductor layer 81.

[0076] With this configuration, the via portion 23 has a higher content of insulating material per unit volume, so its shrinkage behavior during firing becomes closer to that of the base material, the second insulating portion 72, and the adhesion to the second insulating portion 72 is improved. Because the via portion 23 has a higher content of insulating material per unit volume, it is more prone to localized heat generation compared to the first conductor layer 81. However, the intermediate conductor 91 of the via portion 23 is connected to the first conductor layer 81 by protruding toward the first insulating portion 71, and the contact area between the first conductor layer 81 and the intermediate conductor 91 is increased, thus mitigating the amount of localized heat generation in the via portion 23.

[0077] In the holding member 10 of Embodiment 1, the insulating material is preferably alumina.

[0078] Alumina can be used as an insulating material.

[0079] In the holding member 10 of Embodiment 1, it is preferable that a third insulating portion 73 made of an insulating material is provided, the conductor layer CL has a second conductor layer 82 formed between the second insulating portion 72 and the third insulating portion 73, and the second conductor layer 82 has a via connection portion 83 that protrudes toward the first insulating portion 71 and bites into the via portion 23 for connection.

[0080] With this configuration, an interface K2 is formed between the via portion 23 and the via connection portion 83, with a shape that protrudes toward the first insulating portion 71. For example, if the interface K2 has a curved, raised shape in the vertical direction, the contact area between the via portion 23 and the via connection portion 83 increases compared to a linear interface. This improves the adhesion between the via portion 23 and the second conductor layer 82. Furthermore, the electrical resistance between the via portion 23 and the second conductor layer 82 can be reduced. Therefore, the reliability of the connection between the via portion 23 and the second conductor layer 82 can be ensured against shrinkage during firing.

[0081] The manufacturing method for the holding member 10 of Embodiment 1 comprises a first insulating portion 71 made of an insulating material, a second insulating portion 72 made of an insulating material, conductive layers 81 and 82 made of a conductive material, and a via portion 23 made of a conductive material arranged in a through hole 74 that penetrates the second insulating portion 72 in a first direction (vertical direction or Z-axis direction), wherein the conductive layers 81 and 82 are formed between the first insulating portion 71 and the second insulating portion 72, and the manufacturing method for the holding member 10 comprises a first printing step of printing a first conductive paste onto the first surface 171B (bottom surface) of the first green sheet 171(L) which will become the first insulating portion 71 to form the first conductive layer 81(L) before firing, and the second surface 1 The process comprises: a second printing step in which a through hole 74(L) is formed through a second green sheet 172(L) having a top surface 72A, and a second conductive paste is filled into the through hole 74(L) to form a via portion 23(L) before firing; a lamination step in which the first green sheet 171(L) and the second green sheet 172(L) are stacked in a first direction (up and down direction or Z-axis direction) with the first surface 171B (bottom surface) and the second surface 172A (top surface) facing each other to obtain a green sheet laminate (L); and a firing step in which the green sheet laminate L obtained by the lamination step is fired, wherein in the second printing step, the second conductive paste is formed in a form that protrudes from the second surface 172A (top surface).

[0082] According to this method of manufacturing the retaining member 10, the second conductive paste is formed in a shape that protrudes from the second surface 172A (upper surface) toward the first insulating portion 71, which makes it easier for the via portion 23(L) before firing to bite into the first conductor layer 81(L), increasing the contact area between the intermediate conductor 91 and the first conductor layer 81. As a result, the adhesion between the via portion 23 and the first conductor layer 81 is improved, and the reliability of the connection between the via portion 23 and the first conductor layer 81 can be ensured.

[0083] <Other Embodiments> (1) In Embodiment 1, the cross-sectional shape of interfaces K1 and K2 in the vertical direction in Figure 4 was a curved surface, but interfaces K1 and K2 may have a shape other than a curved surface (such as a polygon).

[0084] (2) In Embodiment 1, the connecting electrodes 24 of the holding member 10 were illustrated, but the shape, number, position, size, and range of the connecting electrodes 24 are not limited thereto.

[0085] (3) In Embodiment 1, the via portion 23 of the retaining member 10 was illustrated, but the shape, number, position, size, and range of the via portion 23 are not limited thereto.

[0086] (4) In Embodiment 1, the pad portion 25 and the power supply terminal 26 were illustrated as examples, but the shape, number, arrangement position, size, and arrangement range of the pad portion 25 and the power supply terminal 26 are not limited thereto.

[0087] (5) The method for manufacturing the retaining member 10 shown in Embodiment 1 is just one example, and it may be manufactured by other methods. [Explanation of Symbols]

[0088] 1: Electrostatic chuck (holding device) 10: Retaining member, 10A: Retaining surface, 10B: Bottom surface, 11: Insulating part, 12: Seal band, 13: Protrusion, 14: Reference surface, 15: Terminal hole 20: Base member, 20A: Top surface, 20B: Bottom surface, 21: Refrigerant flow path, 22: Terminal hole, 23: Via section, 24: Connection electrode, 25: Pad section, 26: Power supply terminal 30: Joint part 31: Terminal hole 40: Internal electrode (chuck electrode) 50: Internal electrode (heater electrode) 60: Internal electrode (driver electrode) 71: First insulating part, 72: Second insulating part, 73: Third insulating part, 74: Through hole 81: First conductor layer, 82: Second conductor layer, 83: Via connection, 85: First part of the first conductor layer, 86: Second part of the first conductor layer, 87: Third part of the first conductor layer 90: Via conductor, 91: Intermediate conductor, 95: First part of via intermediate conductor, 96: Second part of via intermediate conductor 110: 1st part, 120: 2nd part 171: First Green Seat 172: Second Green Sheet, 172(L)1: Multiple Second Green Sheets 171A: Top surface, 171B: Bottom surface (first surface) 172A: Top surface (second surface), 172C: Projecting part CL: Conductor layer W: wafer SP: Space K1,K2: Interface R1, R2, R3: 1st area, 2nd area, 3rd area L: Unfired green sheet laminate

Claims

1. A first insulating part made of an insulating material, A second insulating portion made of the aforementioned insulating material, A conductive layer made of a conductive material, A retaining member comprising a via portion made of a conductive material, which is disposed in a through hole that penetrates the second insulating portion in a first direction, The conductor layer has a first conductor layer formed between the first insulating portion and the second insulating portion. The via portion comprises a via conductor placed in the through hole and an intermediate conductor connecting the first conductor layer and the via conductor. The intermediate conductor is connected to the first conductor layer by being embedded in it, with a shape that protrudes toward the first insulating portion side. The third insulating part is made of the insulating material, The conductor layer has a second conductor layer formed between the second insulating portion and the third insulating portion. The second conductor layer has a via connection portion that protrudes toward the first insulating portion and bites into the via portion for connection, and is a retaining member.

2. The intermediate conductor has a first via intermediate conductor portion connected to the via conductor, and a second via intermediate conductor portion formed on the outer circumference of the first via intermediate conductor portion and not connected to the via conductor. The first conductor layer comprises a first portion of the first conductor layer connected to the first portion of the via intermediate conductor, and a second portion of the first conductor layer connected to the second portion of the via intermediate conductor. The first portion is formed by the via intermediate conductor first portion and the first conductor layer first portion, The second portion is formed by the via intermediate conductor second portion and the first conductor layer second portion, The thickness of the first portion of the via intermediate conductor in the first direction is greater than that of the second portion of the via intermediate conductor. The retaining member according to claim 1, wherein the thickness of the second portion in the first direction increases as it approaches the first portion.

3. The conductor layer further comprises the insulating material, The via portion further comprises the insulating material, The holding member according to claim 2, wherein the first conductor layer has a third conductor layer formed on the outer periphery of the second portion of the first conductor layer, and the content of the insulating material per unit volume of the first portion and the content of the insulating material per unit volume of the second portion are each greater than the content of the insulating material per unit volume of the third portion of the first conductor layer, and the thickness of each of the first portion and the second portion in the first direction is greater than the thickness of the third portion of the first conductor layer.

4. The holding member according to claim 3, wherein the content of the insulating material per unit volume of the via portion is greater than the content of the insulating material per unit volume of the first conductor layer.

5. The holding member according to claim 1, wherein the insulating material is alumina.

Images