JP7653252B2 - Retaining device - Google Patents

Description

This disclosure relates to a holding device for holding an object.

There is known a heating device (also called a "susceptor") that holds an object (e.g., a semiconductor wafer) and heats it to a predetermined temperature (e.g., about 400 to 800°C). Heating devices are used as part of semiconductor manufacturing equipment such as film deposition equipment (CVD film deposition equipment, sputtering film deposition equipment, etc.) and etching equipment (plasma etching equipment, etc.).

In general, a heating device includes a ceramic member having a surface (hereinafter referred to as the "holding surface") that is approximately perpendicular to a predetermined direction, and a surface (hereinafter referred to as the "rear surface") opposite to the holding surface. A resistance heating element, such as tungsten (W) or molybdenum (Mo), is disposed inside the ceramic member. A conductive power receiving electrode, at least a portion of which is exposed on the rear surface of the ceramic member, is electrically connected to the resistance heating element. A metal electrode terminal unit is joined to the power receiving electrode by a joint formed of a metal brazing material. When a voltage is applied to the resistance heating element via the electrode terminal unit and the power receiving electrode, the resistance heating element generates heat, and an object held on the holding surface of the ceramic member is heated. For example, a heating device described in JP 2018-49964 A (Patent Document 1 below) is known as such a heating device.

JP 2018-49964 A

The heating device includes a main substrate, a resistive heating element disposed inside the main substrate, and a power receiving electrode connected to an electrode terminal unit. In general, the resistive heating element is connected to the power receiving electrode through a via conductor. The main substrate is formed by stacking and sintering a plurality of green sheets, and the via conductor is formed by providing a through hole in each green sheet, filling the through hole with a metallization paste, and firing the green sheet. Since it is necessary to ensure contact between the via conductor and the power receiving electrode, the height of one via conductor is formed slightly thicker than the thickness of one green sheet. Therefore, the part of the power receiving electrode corresponding to the end of the via conductor protrudes, the flatness of the power receiving electrode is lost, and this is one of the factors that reduces the connection strength between the power receiving electrode and the terminal. In particular, when the resistive heating element and the power receiving electrode are connected through a plurality of via conductors, the end of the via conductor is pushed up against the power receiving electrode.

The holding device of the present disclosure includes a plate-shaped member having a first surface substantially perpendicular to a first direction and a second surface opposite to the first surface, an internal electrode disposed inside the plate-shaped member, a via disposed inside the plate-shaped member extending in the first direction and electrically connected to the internal electrode, a terminal member capable of passing current through the internal electrode, and a conductive connection member electrically connecting the via and the terminal member, the connection member having a via-side connection portion connected to the via and a terminal-side connection portion connected to the terminal member, and the via-side connection portion and the terminal-side connection portion are disposed at different positions in a direction perpendicular to the first direction.

According to the present disclosure, it is possible to suppress a decrease in the connection strength between the terminal member and the terminal side connection portion.

FIG. 1 is a perspective view that illustrates a heating device according to a first embodiment. FIG. 2 is a cross-sectional view showing the internal structure of the heating device. FIG. 3 is an enlarged cross-sectional view of a portion of FIG. FIG. 4 is an enlarged cross-sectional view of a portion of FIG. FIG. 5 is a cross-sectional view showing a state before a plurality of green sheets are thermocompression-bonded together. FIG. 6 is a diagram showing how a metallization paste is printed on the lower surface of a green sheet to form a metallization conductor. FIG. 7 is a diagram showing the arrangement of a plurality of metallized conductors formed on the lower surface of a green sheet. FIG. 8 is a diagram showing the state after the metallization paste has been overcoated with ceramic paste so as to cover all areas other than the surfaces to be connected to the electrode terminals. FIG. 9 is a diagram showing a conventional structure and corresponds to FIG. FIG. 10 is a diagram showing a conventional structure and corresponds to FIG. FIG. 11 is a diagram illustrating the problems in the conventional structure.

[Description of the embodiments of the present disclosure]
First, the embodiments of the present disclosure will be listed and described.
(1) The holding device of the present disclosure comprises a plate-shaped member having a first surface substantially perpendicular to a first direction and a second surface opposite the first surface, an internal electrode arranged inside the plate-shaped member, a via arranged extending in the first direction inside the plate-shaped member and electrically connected to the internal electrode, a terminal member capable of passing electricity through the internal electrode, and a conductive connecting member electrically connecting the via and the terminal member, wherein the connecting member has a via side connection portion connected to the via and a terminal side connection portion connected to the terminal member, and the via side connection portion and the terminal side connection portion are arranged at different positions in a direction perpendicular to the first direction.

The via side connection portion and the terminal side connection portion are disposed at different positions in a direction perpendicular to the first direction. Therefore, even if the portion of the via side connection portion that corresponds to the via is pushed up in the first direction, the terminal side connection portion is flat, so that a decrease in the connection strength between the terminal member and the terminal side connection portion can be suppressed.

(2) It is preferable that the connecting member has a terminal side connecting portion exposed on the second surface side of the plate-shaped member and a terminal side non-connecting portion covered by an insulating member, and that the insulating member is arranged between the terminal side non-connecting portion and the terminal member in the first direction.
Since the terminal side non-connection portion is covered with an insulating member, the size of the exposed surface of the terminal side connection portion (connection member) can be adjusted, and the terminal side connection portion can be prevented from being exposed on the second surface side when connected to the terminal member.

(3) It is preferable that the connection members are provided in a plurality of numbers so as to be arranged circumferentially when viewed in the first direction, and the via-side connection portions are arranged on the outer periphery side of the terminal-side connection portions.
Since the multiple via-side connecting portions can be arranged apart from each other, it is easy to arrange multiple vias.

(4) It is preferable that the connection member includes a configuration in which, when a connection region with the via is a first connection region and a connection region with the terminal member is a second connection region, a plurality of the first connection regions are connected to one second connection region.
Since the number of current paths from the vias to the terminal members increases, the cross-sectional area of the connection members can be increased to reduce conductor resistance, thereby suppressing heat generation.

[Details of the First Embodiment of the Present Disclosure]
Specific examples of the retaining device of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

<Heating device>
The holding device of the present disclosure is a heating device 100 that holds an object (e.g., a semiconductor wafer W) and heats it to a predetermined processing temperature (e.g., 400 to 800° C.), and is also called a susceptor. The heating device 100 is used as a part of a semiconductor manufacturing device such as a film forming device (CVD film forming device, sputtering film forming device, etc.) or an etching device (plasma etching device, etc.). As shown in FIG. 1, the heating device 100 includes a holder 10 and a columnar support 20. The heating device 100 corresponds to the "holding device" in the claims. The technology disclosed in this specification can be applied to electrostatic chucks, holding devices, etc. in addition to heating devices.

<Holding body>
As shown in Fig. 2, the holder 10 is a substantially disk-shaped member having a holding surface S1 and a back surface S2 that are substantially perpendicular to the vertical direction. The holder 10 is formed of an insulating material such as ceramics whose main component is aluminum nitride (AlN) or _alumina ( _Al2O3 ). The main component here means the component with the highest content (weight ratio). The diameter of the holder 10 is, for example, about 100 mm or more and 500 mm or less. The holder 10 corresponds to the "plate-shaped member" in the claims, the vertical direction corresponds to the "first direction" in the claims, the holding surface S1 corresponds to the "first surface" in the claims, and the back surface S2 corresponds to the "second surface" in the claims.

A resistive heating element 50 is embedded inside the holder 10 as a heater electrode for heating the holder 10. The resistive heating element 50 is formed from a conductive material such as tungsten or molybdenum. When viewed from above, the resistive heating element 50 forms a linear pattern that extends in a substantially concentric manner. Both ends of the linear pattern of the resistive heating element 50 are connected to the upper end of the first via 52A via via pads. The resistive heating element 50 corresponds to the "internal electrode" in the claims.

The lower end of the first via 52A is connected to the first land 55A. A via pad 58 is provided below the first land 55A. The first land 55A and the via pad 58 are connected via the second via 52B. A conductive metallized conductor 60 is provided below the via pad 58. The metallized conductor 60 corresponds to the "connecting member" in the claims. The metallized conductor 60 is disposed near the center of the holder 10. The via pad 58 and the metallized conductor 60 are connected via the third via 52C. The portion of the metallized conductor 60 connected to the third via 52C is the via side connection portion 64.

A pair of terminal holes 12 are formed on the rear surface S2 side of the holding body 10. A terminal side electrode 62 is provided at the upper end of each terminal hole 12. The terminal side electrode 62 includes a portion of the metallized conductor 60 (an inner portion IP described later) exposed on the rear surface S2 side of the holding body 10. The resistive heating element 50 and the metallized conductor 60 are electrically connected via each of the vias 52A, 52B, 52C, etc.

<Columnar Support>
The columnar support 20 is a substantially cylindrical member extending in the vertical direction. Like the holder 10, the columnar support 20 is formed of an insulating material such as ceramics mainly composed of aluminum nitride or alumina. The outer diameter of the columnar support 20 is, for example, about 30 mm or more and 90 mm or less, and the height of the columnar support 20 (length in the vertical direction) is, for example, about 100 mm or more and 300 mm or less.

The holder 10 and the columnar support 20 are arranged so that the back surface S2 of the holder 10 and the top surface S5 of the columnar support 20 face each other in the vertical direction. The columnar support 20 is joined near the center of the back surface S2 of the holder 10 via a joint 30 formed from a known joining material.

As shown in FIG. 2, the columnar support 20 has a through hole 22 that opens to the rear surface S2 side of the holder 10. The through hole 22 is a hole that extends in the vertical direction and has a substantially constant inner diameter along the extension direction, and has a substantially circular cross section. A plurality of electrode terminals 74 are housed in the through hole 22. The electrode terminals 74 are substantially circular columnar members when viewed from above, and are formed from a conductive material such as nickel (Ni). The diameter of the electrode terminals 74 is, for example, about 2 mm or more and 6 mm or less.

In addition, a pellet 72 is disposed between the upper end of the electrode terminal 74 and the metallized conductor 60 in the vertical direction. The pellet 72 is a substantially circular plate-shaped member when viewed from above, and is formed of a metal such as tungsten, molybdenum, or kovar. However, since the pellet 72 has the function of reducing the thermal expansion difference between the electrode terminal 74 and the metallized conductor 60, it is preferable that a material having a thermal expansion coefficient between the thermal expansion coefficient of the electrode terminal 74 and the thermal expansion coefficient of the metallized conductor 60 is used as the material for forming the pellet 72. The diameter of the pellet 72 is, for example, about 3 mm or more and 9 mm or less, and the thickness of the pellet 72 is, for example, about 1 mm or more and 6 mm or less. The pellet 72 and the electrode terminal 74 correspond to the "terminal member" in the claims.

3 and 4, the pellet 72 is joined (brazed) to the inside part IP of the terminal side electrode 62 by the first joint part 76 formed by the inactive brazing material. The inactive brazing material means a brazing material that does not substantially chemically bond to ceramics, and is, for example, a Ni-based (Ni-Cr-based alloy, etc.), Au-based (pure Au, Au-Ni-based alloy, etc.), Ag-based (pure Ag, etc.) brazing material. Since the heating device 100 is used in an air environment of about 400 to 800°C, if the brazing material contains a component that is easily oxidized, such as Cu, there is a concern that the brazing material will deteriorate. Therefore, it is preferable that the brazing material does not contain a component that is easily oxidized, such as Cu. In this embodiment, the first joint part 76 is formed so as to face not only the lower surface of the inside part IP of the terminal side electrode 62, but also the back surface S2 of the holder 10. However, since the first joint part 76 is formed by the inactive brazing material, it is not joined to the holder 10.

On the other hand, the pellet 72 is joined to the electrode terminal 74 by a second joint 78 formed of a brazing material. The second joint 78 is, for example, an Ag-based brazing material. The first joint 76 and the second joint 78 correspond to the "terminal member" in the claims.

When a voltage is applied from a power source (not shown) to the resistive heating element 50 via the electrode terminal 74, the second joint 78, the pellet 72, the first joint 76, the metallized conductor 60, the vias 52A, 52B, 52C, the via pads, and the lands 55A, 55B, the resistive heating element 50 generates heat, and the object (e.g., a semiconductor wafer W) held on the holding surface S1 of the holder 10 is heated to a predetermined temperature (e.g., about 400 to 800°C).

<Detailed configuration of metallized conductor>
The configuration of the metallized conductor 60 will be described in more detail. The metallized conductor 60 of this embodiment is formed to include a metal material and a ceramic material. The metal material included in the metallized conductor 60 is, for example, tungsten or molybdenum. The metal material included in the metallized conductor 60 is preferably a metal material having a thermal expansion coefficient close to that of the metal material constituting the pellet 72. The ceramic material included in the metallized conductor 60 is, for example, aluminum nitride or alumina. The ceramic material included in the metallized conductor 60 is preferably a ceramic material having a thermal expansion coefficient close to that of the ceramic material that is the main component of the holder 10.

The terminal side electrode 62 of the metallized conductor 60 is, for example, a substantially circular, flat member when viewed from above. However, the terminal side electrode 62 has a shape in which the outer periphery is bent diagonally upwards all around. That is, the terminal side electrode 62 is composed of an outer periphery portion OP that is bent in this way and located inside the holder 10, and an inner portion IP that is a substantially flat plate and is the portion other than the outer periphery portion OP. The outer periphery portion OP corresponds to the "terminal side non-connected portion" in the claims, and the inner portion IP corresponds to the "terminal side connected portion" in the claims.

The area corresponding to the inner and outer periphery OP of the surface (lower surface) S3 of the terminal side electrode 62 facing the first joint 76 is covered by an insulating member 13 such as a ceramic material constituting the holding body 10, but the area corresponding to the inner part IP is exposed on the back surface S2 side of the holding body 10. The diameter of the inner part IP of the terminal side electrode 62 is, for example, about 3 mm or more and 12 mm or less, and the thickness of the terminal side electrode 62 is, for example, about 0.005 mm or more and 0.15 mm or less. In addition, the maximum thickness (maximum cover thickness) of the insulating member 13 covering the outer periphery OP is, for example, about 0.005 mm or more and 0.1 mm or less. The material of the insulating member 13 is the same as the material of the holding body 10. Since the insulating member 13 is made of the same material as the holding body 10, the insulating member 13 and the holding body 10 can be formed integrally. Furthermore, because the outer periphery OP is covered with an insulating member 13, when the inner parts IP are arranged circumferentially in a plan view, the opposing inner parts IP can be arranged close to each other.

The terminal side electrode 62 and the via side connection portion 64 are provided at different positions in the horizontal direction (direction perpendicular to the up-down direction). The terminal side electrode 62 is connected to the via side connection portion 64 via the relay connection portion 69. The via side connection portion 64, the relay connection portion 69, and the terminal side electrode 62 are arranged at approximately the same height in the up-down direction and are arranged side by side in the horizontal direction. The via side connection portion 64 and the terminal side electrode 62 are arranged at a distance equal to the horizontal length of the relay connection portion 69. In other words, the third via 52C, the electrode terminal 74, and the second joint portion 78 do not overlap in a plan view (top view), and when there are multiple third vias 52C, all the third vias 52C, the electrode terminal 74, and the second joint portion 78 are arranged so as not to overlap in a plan view.

<Method of manufacturing the heating device>
The manufacturing method of the heating device 100 of this embodiment is, for example, as follows: First, the holder 10 and the columnar supports 20 are fabricated.

The method for producing the holder 10 is, for example, as follows. First, an organic solvent such as toluene is added to a mixture of 100 parts by weight of _aluminum nitride powder, 1 part by weight of yttrium oxide ( _Y2O3 ) powder, 20 parts by weight of an acrylic binder, and an appropriate amount of dispersant and plasticizer, and the mixture is mixed in a ball mill for 20 hours to produce a slurry for the green sheet. This slurry for the green sheet is formed into a sheet shape using a casting device and then dried to produce multiple green sheets 65.

In addition, a metal powder such as tungsten or molybdenum is added to and kneaded with a mixture of aluminum nitride powder, an acrylic binder, and an organic solvent such as terpineol to prepare a metallization paste 66. By printing this metallization paste 66 using, for example, a screen printing device, as shown in FIG. 5, an unsintered conductor layer that will later become the resistive heating element 50, the first land 55A, the via pad 58, and the metallization conductor 60 is formed on each specific green sheet 65.

As shown in FIG. 6, the metallized conductor 60 is formed into a horizontally long elliptical shape by printing the metallized paste 66 over the first connection region 53, which is a connection region with the multiple third vias 52C, and the second connection region 54, which is a connection region with the electrode terminal 74 arranged in the terminal hole 12 of the holding body 10. Explaining in more detail with reference to FIG. 7, for example, five second connection regions 54 are provided so as to be arranged on a circumference in a plan view, and the first connection region 53 is arranged on the outer periphery of these second connection regions 54. One first connection region 53 is connected to one second connection region 54, but two first connection regions 53 may be connected to one second connection region 54.

When the third via 52C and the terminal side electrode 62 are arranged offset as in the present disclosure, there is a possibility that the metallized conductor 60 will generate heat. As a countermeasure to this, for example, it is possible to increase the thickness of the metallized conductor 60 to increase its cross-sectional area. However, if the thickness of the metallized conductor 60 is increased, gaps will occur between the metallized paste 66 and the green sheet 65 during manufacturing, which will result in gaps between the metallized conductor 60 and the ceramic member that forms the holder 10, causing cracks and increasing the thickness of the holder 10, making this an unwise solution.

Therefore, if two first connection regions 53 are connected to one second connection region 54 of the metallized conductor 60, the number of current paths from the third via 52C to the terminal electrode 62 will double, so the amount of current passing through one path can be reduced and heat generation can be suppressed. Here, the technical significance of doubling the paths will be considered. Simply doubling the paths means doubling the cross-sectional area, so even if one path is made thicker and wider to double the cross-sectional area, the cross-sectional area is the same, so the resistance value will be the same and it seems that heat generation can be suppressed. However, it has been found from the results of simulations that the current does not flow evenly within the path, but tends to concentrate in the path with the shortest distance. Therefore, it is considered that the resistance value will be smaller and the effect of increasing the paths (the effect of suppressing heat generation) will be more easily obtained by doubling the paths and allowing current to flow through each path to increase the total amount of current, rather than making one path thicker and wider.

In FIG. 7, two first connection regions 53 are connected to the second connection region 54, but three or more first connection regions 53 may be connected to the second connection region 54. Also, in FIG. 7, a single L-shaped metallized conductor 60 is shown connecting two first connection regions 53 and the second connection region 54, but it may be separated into two I-shaped metallized conductors 60.

When printing the metallization paste 66, for example, the metallization paste 66 is printed in one go to a thickness of 50 μm or more, and then dried to volatilize the organic solvent. This process is repeated until the set thickness is reached. Next, as shown in FIG. 8, after printing each metallization paste 66 for the metallization conductor 60, the outer periphery 67 is overcoated with ceramic paste (for example, a mixture of aluminum nitride, an acrylic binder, and an organic solvent such as terpineol) 68 so as to cover the entire periphery.

Next, as shown in FIG. 5, these green sheets 65 are stacked, and then multiple sheets (e.g., 20 sheets) are thermocompressed together, and the outer periphery is cut as necessary to produce a green sheet laminate (e.g., 8 mm thick). This green sheet laminate is cut by machining to produce a disk-shaped compact, which is degreased, and the degreased body is fired to produce a fired body, after which the surface of the fired body is polished. Through these steps, the holder 10 is produced.

The columnar support 20 can be produced, for example, as follows. First, an organic solvent such as methanol is added to a mixture of 100 parts by weight of aluminum nitride powder, 1 part by weight of yttrium oxide powder, 3 parts by weight of PVA binder, and an appropriate amount of dispersant and plasticizer, and the mixture is mixed in a ball mill to obtain a slurry. This slurry is granulated in a spray dryer to produce a raw material powder. Next, the raw material powder is filled into a rubber mold in which a core corresponding to the through hole 22 is placed, and a molded body is obtained by cold isostatic pressing. The obtained molded body is degreased, and the degreased body is further fired. Through the above steps, the columnar support 20 is produced.

Next, the holder 10 and the columnar support 20 are joined. After performing lapping processing on the back surface S2 of the holder 10 and the top surface S5 of the columnar support 20 as necessary, a known bonding agent made into a paste form by mixing, for example, rare earths and organic solvents is uniformly applied to at least one of the back surface S2 of the holder 10 and the top surface S5 of the columnar support 20, and then a degreasing process is performed. Next, the back surface S2 of the holder 10 and the top surface S5 of the columnar support 20 are overlapped and heated to join the holder 10 and the columnar support 20.

After the holder 10 and the columnar support 20 are joined, each pellet 72 is inserted into the through hole 22, and the upper end of each pellet 72 is brazed (950-1150°C, 10-30 minutes) to the lower surface S3 of each terminal electrode 62 using a non-active brazing material (e.g., Ni-based, Au-based, Ag-based brazing material) to form a first joint 76. Also, each electrode terminal 74 is inserted into the through hole 22, and the upper end of each electrode terminal 74 is brazed to each pellet 72 using, for example, an Ag-based brazing material to form a second joint 78. The heating device 100 having the above-mentioned configuration is manufactured mainly by the above manufacturing method.

<Conventional structure and its problems>
Before describing the effects of this embodiment, a conventional structure and its problems will be described. As shown in Figures 9 and 10, conventionally, metallization paste 66 was printed directly on the lower end of via conductor 51. This has the advantage of being advantageous in terms of preventing heat generation in metallization conductor 61, since the distance from via conductor 51 to electrode terminal 74 is shortened and the conductor resistance is reduced.

However, the via conductors 51 are formed by providing through holes in each green sheet, filling the through holes with metallization paste, and firing the green sheet. The height of each via conductor 51 is formed slightly thicker than the thickness of one green sheet. Therefore, when multiple via conductors 51 are stacked, as shown in FIG. 11(A), a part of the via conductor 51 may protrude into the inside of the terminal hole 11, forming unevenness. In such a case, when the metallization paste 66 is printed in the via connection region 53, the metallization paste 66 is printed along the unevenness, and the metallization conductor 61 may also be formed uneven (hereinafter referred to as "via push-up"). Therefore, as shown in FIG. 11(B), when the brazing material 71 is applied to the metallization conductor 61, the lower surface of the brazing material 71 is formed unevenly, and a gap is formed between the lower surface of the brazing material 71 and the upper surface of the electrode terminal 74. As a result, the connection strength between the metallization conductor 61 and the electrode terminal 74 is reduced.

As a result, as shown in FIG. 11(C), it is possible to fill the gap between the metallized conductor 61 and the brazing material 71 by thickening the brazing material 71. In this way, it is possible to eliminate the gap between the metallized conductor 61 and the brazing material 71, and the gap between the brazing material 71 and the electrode terminal 74. However, as the brazing material 71 becomes thicker, the stress caused by the difference in thermal expansion increases, and the load on the joint increases. Furthermore, the adhesion between the metallized conductor 61 and the aluminum nitride (holding body 10) is weak, and the stress from the brazing material 71 makes it easy for the metallized conductor 61 to peel off (crack) from its end.

In addition, in order to eliminate the gap between the brazing material 71 and the electrode terminal 74, if the brazing material 71 is applied in advance to the upper surface of the electrode terminal 74 as shown in FIG. 11(D), the upper surface of the brazing material 71 becomes flat, making it easier for a gap to occur between the metallized conductor 61 and the brazing material 71.

As described above, in the conventional structure, the metallization paste 66 was printed directly on the ends of the via conductors 51, which caused unevenness due to the vias being pushed up, and it was difficult to eliminate the gaps caused by this unevenness. Conversely, if the brazing material 71 was made thicker to avoid such problems, there was a problem that peeling from the ends of the metallization conductors 61 would be more likely to occur.

In addition, when firing is performed, AlN precipitates made of aluminum nitride are generated on the surface of the metallized conductor 61, and many AlN precipitates are generated in particular at positions corresponding to the ends of the via conductors 51 (hereinafter referred to as "via precipitates"). Because the AlN precipitates are an insulator, there is a problem in that the contact area with the electrode terminal 74 becomes small.

<Effects of this embodiment>
The heating device 100 of the present disclosure includes a holder 10 having a holding surface S1 that is approximately perpendicular to the vertical direction and a back surface S2 opposite to the holding surface S1, a resistance heating element 50 arranged inside the holder 10, vias 52A, 52B, 52C that are arranged extending in the vertical direction inside the holder 10 and electrically connected to the resistance heating element 50, a pellet 72 and an electrode terminal 74 that can pass electricity through the resistance heating element 50, and a conductive metallized conductor 60 that electrically connects the vias 52A, 52B, 52C to the pellet 72 and the electrode terminal 74, wherein the metallized conductor 60 has a via side connection portion 64 connected to the vias 52A, 52B, 52C, and an inner portion IP of the terminal side electrode 62 connected to the pellet 72 and the electrode terminal 74, and the via side connection portion 64 and the inner portion IP of the terminal side electrode 62 are arranged at different positions in a direction perpendicular to the vertical direction.

The via side connection portion 64 and the inner part IP of the terminal side electrode 62 are positioned at different positions in a direction perpendicular to the vertical direction. Therefore, even if the parts of the via side connection portion 64 corresponding to the vias 52A, 52B, and 52C are pushed up in the vertical direction, i.e., via push-up occurs, the inner part IP of the terminal side electrode 62 is flat, so that a decrease in the connection strength between the pellet 72 and the electrode terminal 74 and the inner part IP of the terminal side electrode 62 can be suppressed.

In addition, even if AlN precipitates remain in the parts of the via-side connection portion 64 that correspond to the vias 52A, 52B, and 52C, i.e., via precipitation occurs, this does not pose a problem because the AlN precipitates and the green sheet are made of the same material.

The metallized conductor 60 has an inner portion IP exposed on the rear surface S2 side of the holder 10 and an outer peripheral portion OP covered by an insulating member 13, and it is preferable that the insulating member 13 is disposed between the outer peripheral portion OP and the pellet 72 and the electrode terminal 74 in the vertical direction.

When the metallized conductor 60 is heated to a high temperature while exposed on the back surface S2 side, the tungsten in the metallized conductor 60 oxidizes. Therefore, in the above configuration, the outer peripheral portion OP is overcoated with the insulating member 13 so that the size of the exposed surface of the inner portion IP (metallized conductor 60) can be adjusted, and the inner portion IP can be prevented from being exposed on the back surface S2 side when connected to the pellet 72 and electrode terminal 74. Therefore, oxidation of the tungsten in the metallized conductor 60 can be suppressed. In addition, peeling from the end of the metallized conductor 60 can be prevented by overcoating with the insulating member 13.

It is preferable that the metallized conductor 60 includes a configuration in which, when the connection region with the third via 52C is the first connection region 53 and the connection region with the electrode terminal 74 is the second connection region 54, two first connection regions 53 are connected to one second connection region 54.
Since the current path from the third via 52C to the electrode terminal 74 is doubled, the cross-sectional area of the metallized conductor 60 can be increased to reduce the conductor resistance, thereby suppressing heat generation.

<Other embodiments>
(1) In the above embodiment, the pellet 72 is disposed between the electrode terminal 74 and the terminal electrode 62, but the electrode terminal 74 and the terminal electrode 62 may be joined by a joint formed of a brazing material without disposing the pellet 72. In such a configuration, the brazing material and the electrode terminal 74 correspond to the "terminal member" in the claims.

(2) In the above embodiment, the terminal side electrode 62 has a shape in which the outer peripheral portion of a substantially flat plate-like member is bent obliquely upwards all around, but the terminal side electrode may have another shape as long as the outer peripheral portion is disposed inside the holder 10 and the inner portion is exposed to the terminal hole 12.

(3) In the above embodiment, the configuration of the terminal side electrode 62 electrically connected to the resistive heating element 50 arranged inside the holder 10 was described, but the terminal side electrode electrically connected to other internal electrodes arranged inside the holder 10 may have a similar configuration.

(4) The materials used to form each component in the heating device of the above embodiment are merely examples, and each component may be formed from other materials. In addition, the manufacturing method for the heating device of the above embodiment is merely an example, and various modifications are possible.

(5) Furthermore, the present disclosure is not limited to the heating device 100, but is also applicable to other holding devices (e.g., electrostatic chucks, etc.) that include a ceramic member, an internal electrode (heater electrode, chuck electrode, RF electrode, etc.) disposed inside the ceramic member, a via electrically connected to the internal electrode, a terminal member capable of passing current through the internal electrode, and a conductive connecting member electrically connecting the via and the terminal member, and that hold an object on the surface of the ceramic member.

(6) In the above embodiment, the outer periphery OP of the terminal side electrode 62 is covered by the insulating member 13, but the outer periphery OP may be exposed inside the terminal hole 12.

(7) In the above embodiment, the via-side connection portion 64 is disposed on the outer periphery side of the inner portion IP of the terminal-side electrode 62, but both the via-side connection portion and the inner portion of the terminal-side electrode may be disposed on the circumference in a plan view.

LIST OF SYMBOLS 10...Holding body (plate-shaped member) 11...Terminal hole 12...Terminal hole 13...Insulating member 20...Columnar support 22...Through hole 30...Joint 50...Resistive heating element (internal electrode) 51...Via conductor 52A...First via 52B...Second via 52C...Third via 53...First connection region 54...Second connection region 55A...First land 55B...Second land 56...Via 57...Via 58...Via pad 60...Metallized conductor (connecting member) 61...Metallized conductor 62...Terminal side electrode 64...Via side connection portion 65...Green sheet 66...Metallized paste 67...Outer periphery 68...Ceramic paste 69...Relay connection portion 71...Brazing material 72...Pellet (terminal member) 74...Electrode terminal (terminal member) 76...First joint portion 78...Second joint portion 100...Heating device (holding device)
CD: Direction of current flow IP: Inner part (terminal side connected part) OP: Outer part (terminal side non-connected part)
S1: Holding surface (first surface) S2: Back surface (second surface) S3: Lower surface S5: Upper surface W: Semiconductor wafer (object)

Claims (3)

a plate-like member having a first surface substantially perpendicular to a first direction and a second surface opposite to the first surface;
an internal electrode disposed inside the plate-shaped member;
a via disposed inside the plate-like member and extending in the first direction and electrically connected to the internal electrode;
a terminal member capable of conducting electricity to the internal electrode;
a conductive connection member that electrically connects the via and the terminal member,
the connection member has a via-side connection portion connected to the via , and a terminal-side connection portion connected to the terminal member , the terminal member and the terminal-side connection portion being connected to each other without any vias;
the via-side connection portion and the terminal-side connection portion are disposed at different positions in a direction perpendicular to the first direction,
when a connection region of the connection member with the via is defined as a first connection region and a connection region with the terminal member is defined as a second connection region, a plurality of the second connection regions are provided so as to be arranged circumferentially when viewed in the first direction,
A holding device , wherein the first connection region is disposed on an outer circumferential side relative to the second connection region . The holding device according to claim 1, wherein the connection member has the terminal side connection portion exposed on the second surface side of the plate-like member and a terminal side non-connection portion covered by an insulating member, and the insulating member is disposed between the terminal side non-connection portion and the terminal member in the first direction. The holding device according to claim 1 or 2 , wherein the connection member includes an aspect in which a plurality of the first connection regions are connected to one of the second connection regions.

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