JP2023050778A - Joined body, manufacturing method thereof, and electrode-embedded member - Google Patents

Abstract

To provide a joined body capable of joining an insulation layer comprising a ceramic sintered body of AlN as a main constituent on an intended surface of a metal member which becomes a base of a substrate-holding member and the like, capable of heightening electrical insulation properties, and capable of suppressing erosion and contamination of a joined face of the metal member and the insulation layer, a production method of the same, and an electrode-embedded member.SOLUTION: A joined body 100 includes a metal member 10 comprising a high melting point metal having a melting point of 2,000°C or higher, and an insulation layer 30 comprising a ceramic sintered body of AlN as a main constituent, where a maximum thickness of the metal member 10 in a direction vertical to one principal plane 12 is 1 mm or more, and the insulation layer 30 is directly joined to at least a part of the metal member 10 excluding two planes of the one principal plane 12, and the other principal plane 14 at a side facing the one principal plane 12.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a bonded body, a manufacturing method thereof, and an electrode-embedded member.

AlN members used in semiconductor manufacturing equipment are sometimes joined to metal members for the purpose of adding various functions.

Patent Literature 1 discloses a joined body and a semiconductor holding device in which an aluminum nitride member and a metal member are joined with Al brazing material. As a preferred embodiment, the aluminum nitride member is a semiconductor holding member having an installation surface for installing a semiconductor wafer, and the metal member is a heat transfer member for transferring heat between the semiconductor holding member and the outside. An example is disclosed that is a member. It also discloses that the heat transfer member is made of tungsten, molybdenum, copper, or an alloy thereof. These metal members function as heat sinks and have a certain thickness.

In addition, in Patent Document 2, a sintered metal layer having a relatively large thickness and high conductivity is incorporated, and warping is suppressed to an extremely low level. A sintered metal layer made of tungsten or molybdenum and having a thickness of 15 to 100 μm is provided on at least a part of the bonding surface for the purpose of providing an aluminum nitride bonded body that has high strength and is suitable for use as an electrode-embedded member, and a method for manufacturing the same. is formed of aluminum nitride sintered bodies, wherein the sintered metal layer has a sheet resistance value of 1 Ω/□ or less and a warp of the sintered metal layer of 100 μm/100 mm or less A conjugate is disclosed.

JP-A-9-249465 JP-A-2005-159334 JP-A-5-246769 JP-A-62-78167

Journal of the Japan Institute of Metals, Vol. 45, No. 2 (1981) p. 184-P. 189

AlN ceramics used in semiconductor manufacturing processes are sometimes integrated with high-melting-point metals used for heat sinks and the like. For this purpose, the refractory metal must have a certain thickness or more, but the sintered metal layer as disclosed in Patent Document 2 cannot have such a structure.

In addition, according to Non-Patent Document 1, it has been considered difficult to produce a bonded body because AlN and a high-melting-point metal do not react without a bonding material. Therefore, conventionally, a joined body of AlN ceramic and a high-melting-point metal has been manufactured by a method of joining by interposing a brazing material or the like at the joint interface (Patent Documents 1, 3, and 4).

However, when these bonded bodies are used in a semiconductor manufacturing process, the methods of Patent Documents 1, 3, and 4 raise concerns about erosion of the brazing material that is the bonding layer and contamination from the bonding layer. Therefore, an AlN-high melting point metal joined body, which is a joined body of AlN ceramic and a thick high melting point metal, and which suppresses the risk of contamination and corrosion from the joining material, has been desired.

Furthermore, these joints often need to be electrically insulated from the heater electrodes embedded in AlN and peripheral members. Conventionally, an insulating thermal spray film such as alumina is formed on the exposed surface of the high-melting-point metal, or a sleeve made of alumina or the like is prepared for the hole penetrating the high-melting-point metal, and is adhered to act as an insulator. things have been done.

However, when the exposed surface is coated with a thermally sprayed film, there are many restrictions on the shape of the exposed surface, and in general, a uniform film cannot be obtained unless the surface is flat. Furthermore, the sprayed film itself usually has a porosity of about 5%, and in some cases it is not sufficient from the viewpoint of electrical insulation.

Also, when a sleeve is glued, the temperature at which the bonded body can be used is restricted by the adhesive, and generally used organic adhesives can only achieve heat resistance of about 200°C. could not be applied.

The present invention has been made in view of such circumstances, and is capable of bonding an insulating layer made of a ceramic sintered body containing AlN as a main component to a desired surface of a metal member serving as a base of a substrate holding member or the like. An object of the present invention is to provide a joined body, a method for producing the same, and an electrode-embedded member, which can improve electric insulation and suppress erosion and contamination of the joint surface of the metal member and the insulating layer.

(1) In order to achieve the above object, the joined body of the present invention is a joined body of an insulating layer made of a metal member made of a high melting point metal having a melting point of 2000° C. or higher and a ceramic sintered body containing AlN as a main component. wherein the maximum thickness in a direction perpendicular to one main surface of the metal member is 1 mm or more, and the insulating layer is formed on the one main surface of the metal member and the side facing the one main surface. It is characterized in that it is directly bonded to at least a portion of the other main surface except for two surfaces.

As a result, an insulating layer made of a ceramic sintered body containing AlN as a main component can be bonded to a desired surface of a metal member that serves as a base such as a substrate holding member, and a bonded body with improved electrical insulation can be obtained. . Also, erosion and contamination of the joint surface between the metal member and the insulating layer can be suppressed. Moreover, since the thickness of the metal member is large, it can be applied to various uses such as using the metal member as a heat sink.

(2) Further, in the joined body of the present invention, the metal member has a carbide layer containing a carbide of the high-melting-point metal in the vicinity of the joint interface between the insulating layer and the metal member, and the average of the carbide layer The thickness is characterized by being 40 μm or less.

By reducing the average thickness of the carbide layer of the high-melting-point metal in the vicinity of the bonding interface between the insulating layer and the metal member, the bonding strength between the insulating layer and the metal member can be increased, and the electrical insulation properties of the metal member can be improved. Increased reliability.

(3) Further, in the joined body of the present invention, the metal member has a through hole penetrating in a thickness direction, or a groove portion on one main surface, the other main surface, or a side surface, and the insulating layer includes the It is characterized in that it is bonded to the inner surface of the through-hole or the surface including the groove.

In this way, the metal member has a through hole penetrating in the thickness direction, or a groove on one main surface, the other main surface, or a side surface, and the insulating layer is bonded to the inner surface of the through hole or the surface including the groove. As a result, the insulating layer can be formed on the inner surface of the through-hole or the surface including the groove, which has been difficult to directly bond, further expanding the applications of the bonded body.

(4) In addition, in the joined body of the present invention, the metal member contains 1 wt % or less of a second metal oxide, which is an oxide of a metal different from the high-melting-point metal.

In this way, when the metal member contains 1 wt % or less of the second metal oxide, which is an oxide of a metal different from the high-melting-point metal, the bonding strength between the insulating layer and the metal member increases, and the metal member becomes electrically conductive. Insulation reliability is enhanced.

(5) Further, in the joined body of the present invention, a first ceramic member made of a ceramic sintered body containing AlN as a main component is joined to the one main surface of the metal member. .

By joining the ceramic member to one main surface of the metal member in this manner, a joined body using the metal member as a base can be obtained, and the joined body can be applied to a substrate holding member or the like. Moreover, since the thickness of the metal member is large, it can be applied to various uses such as using the metal member as a heat sink.

(6) Further, in the bonded body of the present invention, a second ceramic member made of a ceramic sintered body containing AlN as a main component is further bonded to the other main surface of the metal member. there is

By bonding the ceramic members to both main surfaces of the metal members in this way, the reliability of the electrical insulation of the exposed surfaces of the metal members is increased, and the internal stress of the bonded body is balanced, resulting in better bonding. The reliability of the body is improved, and the application of the joined body is further expanded.

(7) Further, an electrode-embedded member of the present invention is characterized by comprising the joined body described in (5) above and an electrode embedded in the first ceramic member of the joined body.

By using the electrode-embedded member in which the electrode is embedded in the first ceramic member of the joined body in this way, the electrode-embedded member can be used as a heater module having a heater function.

(8) A method for manufacturing a joined body of the present invention includes a metal member made of a high melting point metal having a melting point of 2000° C. or higher and an insulating layer made of a ceramic sintered body containing AlN as a main component. A preparation step of preparing granulated powder obtained by granulating AlN raw material powder or powder obtained by adding metal oxide raw material powder to AlN raw material powder; and a plate-like metal member precursor having a thickness of 1 mm or more made of the refractory metal is arranged in a carbon mold so that one main surface of the metal member precursor is perpendicular to the stacking direction, and the metal member precursor A filling lamination step of laminating so that the granulated powder or the molded body is filled in the gap between the side surface and the carbon mold, and a laminate forming step of inserting a carbon punch into the carbon mold to form a laminate , a firing step of uniaxial pressure firing of the laminate, and a removal processing step of removing and processing the ceramic sintered body formed in the metal member precursor after the uniaxial pressure firing, leaving a predetermined thickness. is characterized by including

As a result, a joined body having highly reliable electrical insulation on the side surfaces of the metal members can be obtained. Due to the thickness of the metal members, it can be used for a variety of applications, such as using the metal members as a heat sink, or as a base to increase the strength and dimensional accuracy of ceramics, when applying the bonded body to a substrate holding member, etc. can be applied to

(9) Further, in the method for manufacturing a joined body of the present invention, the metal member precursor has a through hole penetrating in a thickness direction, or a groove portion on one main surface, the other main surface, or a side surface, and The removal processing step includes a step of removing the ceramic sintered body formed in the through hole or the groove while leaving a predetermined thickness.

As a result, the insulating layer can be formed on the inner surface of the through-hole or the surface including the groove, which has been difficult to directly bond, further expanding the applications of the bonded body.

According to the present invention, an insulating layer made of a ceramic sintered body containing AlN as a main component can be bonded to a desired surface of a metal member that serves as a base such as a substrate holding member, thereby providing a bonded body with improved electrical insulation. be able to. Also, erosion and contamination of the joint surface between the metal member and the insulating layer can be suppressed.

1 is a schematic cross-sectional view showing an example of a joined body according to a first embodiment of the present invention; FIG. FIG. 5 is a schematic cross-sectional view showing a modified example of the joined body according to the first embodiment of the present invention; FIG. 5 is a schematic cross-sectional view showing an example of a joined body according to a second embodiment of the present invention; FIG. 5 is a schematic cross-sectional view showing a modification of the joined body according to the second embodiment of the present invention; FIG. 5 is a schematic cross-sectional view showing an example of an electrode-embedded member according to a second embodiment of the present invention; 4A to 4E are cross-sectional views schematically showing one stage of the manufacturing process of the manufacturing method according to the embodiment of the present invention, respectively; FIG. 4A to 4E are cross-sectional views schematically showing one stage of the manufacturing process of the manufacturing method according to the embodiment of the present invention, respectively; FIG. FIG. 2 is a schematic diagram of a cross section obtained by vertically cutting the side surface of Example 1;

Next, embodiments of the present invention will be described with reference to the drawings. In order to facilitate understanding of the description, the same reference numerals are given to the same components in each drawing, and overlapping descriptions are omitted. In addition, in the configuration diagram, the size of each component is conceptually represented, and does not necessarily represent the actual size ratio.

[First Embodiment]
[Structure of conjugate]
A joined body according to a first embodiment of the present invention will be described. FIG. 1 is a schematic cross-sectional view showing an example of a joined body according to a first embodiment of the invention. A joined body 10 according to the first embodiment of the present invention is formed by joining a metal member 10 made of a high melting point metal having a melting point of 2000° C. or higher and an insulating layer 30 made of a ceramic sintered body mainly composed of AlN. formed. The metal member 10 made of a high-melting-point metal can be molybdenum (Mo), tungsten (W), tantalum (Ta), etc., with a melting point of 2000° C. or higher, and refers to those with a purity of 99 wt % or higher. As a result, deformation of the metal member 10 is suppressed even at the temperature during uniaxial pressure firing. At the same time, since a high melting point metal oxide having a relatively high melting point of 900° C. or higher is formed at the interface between the metal member 10 and the insulating layer 30, deformation of the joint interface between the metal member 10 and the insulating layer 30 is prevented. can be suppressed. The insulating layer 30 containing AlN as a main component means containing 90 wt % or more of AlN.

In the bonded body 100, an insulating layer 30 is directly bonded to at least a part of the metal member 10 except for two main surfaces 12 and 14 of the metal member 10. . To be directly joined means to be joined without using another member such as brazing material or adhesive. As a result, the insulating layer 30 made of a ceramic sintered body containing AlN as a main component can be directly bonded to the desired surface of the metal member 10 that serves as a base for a substrate holding member or the like, thereby suppressing corrosion and contamination of the bonding surface. , the joined body 100 with improved electrical insulation can be obtained. The thickness of the insulating layer 30 is preferably 1 mm or more. The thickness of the insulating layer may not be constant.

Metal member 10 has a maximum thickness of 1 mm or more in a direction perpendicular to one main surface 12 of metal member 10 . Since the metal member 10 is thick as described above, the metal member 10 can be used for various purposes such as a base for a substrate holding member, a heat sink, or a heat spreader. One main surface 12 of the metal member 10 is one surface perpendicular to the thickness direction of the metal member 10 or a surface having the largest area. The metal member 10 having a large thickness means that the maximum thickness of the metal member 10 in a direction perpendicular to one main surface 12 is 1 mm or more. If the maximum thickness of the metal member 10 is less than 1 mm, the metal member 10 may be deformed or its application may be limited. Moreover, it is preferable that the average thickness of the metal member 10 in the direction perpendicular to the main surface 12 is 1 mm or more.

The maximum thickness in the direction perpendicular to one main surface 12 of the metal member 10 is preferably set according to the intended use. Considering that there was no joined body 100 with a thick metal member 10 like the present invention, the thickness is preferably 2 mm or more, more preferably 3 mm or more, and 4 mm or more depending on the application. is more preferred. Also, the side surface 16 of the metal member 10 may be uneven, curved, or tapered.

Metal member 10 may have a carbide layer containing carbide of a high-melting-point metal in the vicinity of the joint interface between metal member 10 and insulating layer 30 . When metal member 10 has a carbide layer, the average thickness of the carbide layer is 40 μm or less. Since the carbide layer containing the carbide of the refractory metal is an embrittlement layer, reducing the average thickness of the carbide layer in the vicinity of the bonding interface between the metal member 10 and the insulating layer 30 allows the metal member 10 and the insulating layer 30 to It is possible to obtain a bonded body 100 in which the bonding strength of the bonding surface can be increased and erosion and contamination of the bonding surface are suppressed. The average thickness of the carbide layer of metal member 10 is preferably 5 μm or less. By reducing the average thickness of the carbide layer containing the carbide of the high-melting-point metal in this manner, the bonding strength between the metal member 10 and the insulating layer 30 increases, and the reliability of the bonded body increases. The vicinity of the bonding interface will be described later.

The carbide layer containing refractory metal carbide is affected by the composition of AlN forming the insulating layer 30, and is also affected by the presence or absence of metal oxides contained in AlN and the addition amount thereof. Therefore, it is presumed that the C component of the carbide layer of the high-melting-point metal is the residual carbon of the granulated powder due to the addition of the metal oxide or the contamination from the environment.

FIG. 2 is a schematic cross-sectional view showing a modification of the joined body according to the first embodiment of the present invention. As shown in FIG. 2, the metal member 10 preferably has a through hole 20 penetrating in the thickness direction, or a groove 22 on one main surface 12 , the other main surface 14 , or the side surface 16 . Moreover, in that case, the insulating layer 30 is preferably bonded to the inner surface of the through-hole 20 or the surface including the groove portion 22 . In this way, the metal member 10 has a through hole 20 penetrating in the thickness direction, or a groove 22 on one main surface 12, the other main surface 14, or a side surface 16, and the insulating layer 30 is formed on the inner surface or the inner surface of the through hole 20. By bonding to the surface including the groove 22, the insulating layer 30 can be formed on the inner surface of the through-hole 20 or the surface including the groove 22, which has been difficult to directly bond, and the application of the bonded body 10 is further expanded.

The groove part 22 includes a case where it is a step. Further, when the groove 22 is provided on one main surface 12 or the other main surface 14, the inside of the groove 22 is a portion of the metal member 10 excluding the two main surfaces 12 and 14. may be

The insulating layer 30 may contain a second phase of metal oxide. When the insulating layer 30 contains the second phase of metal oxide, the metal constituting the metal oxide of the second phase is preferably one or more selected from Y and Ca, and Y is preferred. more preferred. The metal oxide constituting the second phase may be a sintering aid for a ceramic sintered body containing AlN as a main component. In that case, the metal oxide constituting the second phase may be added in a necessary amount as a sintering aid for the ceramic sintered body. For example, when Y is added as a sintering aid, it may be added in an amount of 0.1 wt % or more and 5 wt % or less in terms of Y ₂ O ₃ . Alternatively, the insulating layer 30 may be composed only of AlN.

The metal member 10 preferably contains 1 wt % or less of the second metal oxide, which is an oxide of a metal different from the refractory metal. When the metal member 10 contains 1 wt % or less of the second metal oxide, the bonding strength between the metal member 10 and the insulating layer 30 increases, and the reliability of the joined body 100 increases. The metal constituting the second metal oxide is preferably one or more selected from Y, Ce, and Ca, and more preferably Y or Ce. When the insulating layer 30 contains the second phase of metal oxide, the metal forming the second metal oxide is the same as the metal forming the second phase metal oxide of the insulating layer 30. good too. These metal oxide components preliminarily contained in the metal member 10 increase the concentration of metal and oxygen at the bonding interface, thereby increasing the bonding strength.

The oxygen concentration at the bonding interface between the metal member 10 and the insulating layer 30 is preferably higher than the oxygen concentration inside the insulating layer 30 . Further, when the insulating layer 30 contains a second phase made of a metal oxide, the bonding interface between the metal member 10 and the insulating layer 30 has a metal concentration and an oxygen concentration that constitute the second phase of the insulating layer 30. It is preferable that the concentration of the metal and the oxygen concentration inside the insulating layer 30 are respectively higher. In this manner, the oxygen concentration at the joint interface between the metal member 10 made of a high-melting-point metal and the insulating layer 30 made of a ceramic sintered body containing AlN as a main component is higher than the oxygen concentration inside the insulating layer 30, or the second Since the metal concentration and oxygen concentration of the phase are higher than the metal concentration and oxygen concentration inside the insulating layer 30, the metal member 10 and the insulating layer 30 are joined through these, and the joint surface is eroded. and a conjugate with suppressed contamination can be obtained.

The reason why the oxygen concentration in the vicinity of the bonding interface increases is that the natural oxide film formed on the surface of the high-melting metal reacts with the high-melting-point metal, generating a high-melting-point metal oxide exhibiting a melting point of 900°C or higher during firing. It is presumed that part of these melts and diffuses toward the ceramic sintered body.

Note that the bonding interface between the metal member 10 and the insulating layer 30 refers to an interface where the concentration of the metal element that mainly constitutes the metal member 20 sharply decreases in cross-sectional elemental mapping by EDX or EPMA. Further, the inside of the insulating layer 30 is defined as a region separated by 1 mm or more in the direction of the insulating layer 30 (ceramic sintered body) perpendicular to the straight line when the joint interface is approximated by a straight line. In addition, when the insulating layer 30 is thinner than 1 mm, the region 500 μm inside from the surface of the insulating layer 30 farthest from the bonding interface, or the region further away from the bonding interface among the intermediate regions of the thickness of the insulating layer 30 is insulated. Inside layer 30 . When the insulating layer 30 contains a second phase of metal oxide, it can be said that the concentration of the metal forming the second phase of the insulating layer 30 is uniform. Further, the vicinity of the bonding interface is defined as a range within 100 μm perpendicular to the straight line when the bonding interface is approximated by a straight line. A carbide layer of refractory metal is contained entirely near the bond interface.

Changes in the concentration of metal, carbon, and oxygen existing in the metal member 10, the insulating layer 30, or their bonding interfaces can be determined by comparing the intensity (number of counts) of the characteristic X-rays of the relevant region by EPMA. This makes it possible to relatively evaluate the difference in metal, carbon, and oxygen concentrations near and inside the interface.

The presence of the refractory metal carbide layer can be confirmed by cross-sectional elemental mapping by EDX or EPMA, and the thickness can be measured by cross-sectional SEM observation or optical microscope observation. The average thickness of the carbide layer of the refractory metal is confirmed, for example, by drawing 10 equally spaced straight lines at 10 μm intervals perpendicular to a straight line approximating the bonding interface on a 1000× SEM image of the carbide layer. It can be measured by calculating the average value of the length of the line segment that overlaps with . The average value is taken as the average thickness of the refractory metal carbide layer in that field. In order to obtain an overall average value, it is preferable to further average the average values obtained in three or more fields of view. Here, when the carbide layer is so thin that it is difficult to confirm it in the SEM image, it is evaluated to be at least 2 μm or less, which is measurable.

Metal member 10 may not have a carbide layer of a high-melting-point metal in the vicinity of the bonding interface between metal member 10 and insulating layer 30 . The fact that there is no refractory metal carbide layer near the bonding interface means that when the bonding interface is approximated by a straight line in elemental mapping of the cross section by EDX or EPMA, the C component is detected within a range of 100 μm perpendicular to the straight line. It means that it will not be done.

Preferably, the insulating layer 30 further contains a Group 4 metal, and the metal member 10 has the Group 4 metal diffused therein. Since the insulating layer 30 contains the Group 4 metal and the Group 4 metal is diffused in the metal member 10, the bonding strength between the metal member 10 and the insulating layer 30 is increased. 100 becomes more reliable. The Group 4 metal is preferably one or more selected from Ti and Hf, more preferably Ti.

[Second embodiment]
A joined body according to a second embodiment of the present invention will be described. FIG. 3 is a schematic cross-sectional view showing an example of a joined body according to a second embodiment of the invention. Since the joined body 200 according to this embodiment has the same basic configuration as the joined body 100 according to the first embodiment, only different points will be described below.

A joined body 200 according to the present embodiment is formed by joining a first ceramic member 40 made of a ceramic sintered body containing AlN as a main component to one main surface 12 of a metal member 10 . At this time, the metal member 10 preferably has a maximum diameter of 50% or more of the maximum diameter of the first ceramic member 40 . Also, the first ceramic member 40 is preferably bonded to the entire one main surface 12 of the metal member 10 . By having these characteristics, the metal member 10 can be applied in a form suitable for various uses. Moreover, it is preferable that the first ceramic member 40 is directly bonded to one main surface 12 of the metal member 10 without interposing any other member. This is because if another member is interposed, the bonding strength may decrease.

By bonding the first ceramic member 40 to one main surface 12 of the metal member 10 in this manner, the bonded body 200 using the metal member 10 as a base can be formed. It can be applied to various uses such as increasing the strength and dimensional accuracy of one ceramic member 40, and the joined body 200 can be applied to a substrate holding member and the like.

FIG. 4 is a schematic cross-sectional view showing a modification of the joined body according to the second embodiment of the invention. As shown in FIG. 4, the joined body 200 has a second ceramic sintered body mainly composed of AlN on the other main surface 14 of the metal member 10 facing the main surface 12. Preferably, member 45 is also joined. By bonding the ceramic members 40 and 45 to both the main surfaces 12 and 14 of the metal member 10 in this way, the internal stress of the bonded body 200 is balanced, thereby improving the reliability of the bonded body 200. The use of the joined body 200 is further expanded. Moreover, by sandwiching the plate-like high-melting-point metal (metal member 10) between the ceramic members 40 and 45, warping of the joined body 200 can be suppressed, and the joined body 200 with high dimensional accuracy can be manufactured.

The first ceramic member 40 and the second ceramic member 45 are both made of a ceramic sintered body containing AlN as a main component. may be different. Also, the compositions of the first ceramic member 40 and the second ceramic member 45 may be the same or different. The first ceramic member 40 or the second ceramic member 45 and the insulating layer 30 are preferably formed integrally. The first ceramics member 40 or the second ceramics member 45 may be bonded to function as the insulating layer 30 .

[Structure of Electrode-Embedded Member]
Next, an electrode-embedded member according to an embodiment of the present invention will be described. FIG. 5 is a schematic cross-sectional view showing an example of the electrode-embedded member according to the second embodiment of the present invention. An electrode-embedded member 250 according to the second embodiment of the present invention includes a joined body 200 and electrodes 50 embedded in the first ceramic member 40 of the joined body 200 .

The bonded body 200 is the bonded body 200 described above. The electrode 50 is embedded in the first ceramic member 40 of the joined body 200 . The shape of the electrode 50 can be various shapes such as a mesh shape and a foil shape. Also, various materials such as molybdenum and tungsten can be used. Electrode 50 can be used as a heater electrode.

The electrode embedded member 250 may be provided with terminal holes and terminals (not shown).

The bonded body and electrode-embedded member of the present invention can bond an insulating layer made of a ceramic sintered body containing AlN as a main component to a desired surface of a metal member that serves as a base such as a substrate holding member, and the exposed surface of the metal member. can be assembled with the peripheral member by electrically insulating the member, so that the member can be a member with improved electrical insulation. In addition, since the sleeve is integrally formed with the metal member, the heat resistance temperature can be increased as compared with the conventional one. In addition, since it is possible to obtain a member that suppresses erosion and contamination of the joint surface between the metal member and the insulating layer, it can be applied to various uses. Further, by arranging the sealing member on the side surface of the metal member, it is also possible to ensure necessary airtightness.

[Method for producing joined body]
Next, a method for manufacturing the bonded bodies 100 and 200 configured as described above will be described. 6A to 6E are cross-sectional views schematically showing one stage of the manufacturing process of the manufacturing method according to the embodiment of the present invention. A manufacturing method according to an embodiment of the present invention includes a preparation process, a filling lamination process, a laminate formation process, a firing process, and a removal processing process.

In the preparation step, granulated powder 32 is prepared by granulating AlN raw powder or AlN raw powder to which metal oxide raw powder is added. The AlN raw material powder preferably has a high purity, and the purity is preferably 96% or higher, more preferably 98% or higher. Also, the average particle diameter of the AlN powder is preferably 0.1 μm or more and 1.0 μm or less, more preferably 0.3 μm or more and 0.8 μm or less. For example, when Y ₂ O ₃ is used as the metal oxide raw powder, 0.1 wt % to 5 wt % of Y ₂ O ₃ is added to the AlN raw powder, and a binder such as PVA, a dispersant, and a solvent are added. is added to prepare a slurry, and the granulated powder 32 is granulated with a spray dryer or the like.

In the filling lamination step, a plate-shaped metal member precursor 24 having a thickness of 1 mm or more and made of a high-melting-point metal is prepared, and the granulated powder 32 or the compact formed from the granulated powder 32 and the metal member precursor 24 are coated with metal. The member precursor 24 is placed in a bottomed carbon mold 60 (molding mold) so that one main surface 12 of the member precursor 24 is perpendicular to the stacking direction, and granulated in the gap between the side surface 16 of the metal member precursor 24 and the carbon mold 60 . Lamination is performed so that the powder 32 or the compact is filled.

As another example of stacking compacts, the obtained granulated powder 32 is used to produce one or more compacts. As a method for molding the molded body, for example, a known method such as uniaxial pressure molding or cold isostatic pressing (CIP) method may be used. The method for forming the molded body is not limited to pressure molding, and can be applied to, for example, green sheet lamination or cast molding.

In the case of producing the electrode-embedded member 250, when the granulated powder 32 is filled, the granulated powder 32 is temporarily pressed, the electrode 50 is arranged, and the granulated powder 32 is added and temporarily pressed, or alternatively, the compact is formed. The electrode 50 is embedded in the portion that will become the first ceramics member 40 after sintering by stacking and arranging the electrode 50 and then stacking the molded body.

In the laminate forming step, the carbon punch 70 is inserted into the carbon mold 60 to form the laminate 34 . The laminated body 34 may be composed of two layers of the granulated powder 32 or the molded body layer that becomes the ceramic sintered body 36 after sintering and the metal member precursor 24 that becomes the metal member 10 after sintering. The member precursor 24 may be three layers sandwiched between layers of the granulated powder 32 or the compact. In addition, the side surface in the stacking direction may have a portion where the metal member precursor 24 is exposed in a region where the insulating layer 30 is not formed, but the region where the insulating layer 30 is not formed is also covered with the granulated powder 32 or the compact. It is preferable that the sintered surface is fired at a low temperature and then exposed by grinding after sintering. FIG. 6 shows the case where the metal member precursor 24 is covered with the granulated powder 32 and produced in three layers.

In the firing process, the joined bodies 100 and 200 are produced by firing the laminate 34 under uniaxial pressure. The firing conditions are, for example, a temperature of 1700° C. or more and 2000° C. or less, a pressure of 1 MPa or more, and the firing can be performed by holding for 0.1 hour or more and 10 hours or less. At this time, the granulated powder 32 or the molded body formed from the granulated powder 32 is subjected to a hydrostatic force and pressed against the side surface 16 of the metal member precursor 24, and the ceramic sintered body 36 becomes the metal member precursor. 24 without a bonding material interposed therebetween to be integrated.

At this time, the step of uniaxial pressure firing is controlled so that the average thickness of the carbide layer containing the carbide of the high melting point metal in the vicinity of the bonding interface between the insulating layer 30 and the metal member 10 in the metal member 10 is 40 μm or less. is preferred. As the amount of additive contained in the granulated powder 32 increases, the carbide layer of the high-melting-point metal tends to thicken faster. Therefore, it is preferable to shorten the firing time and lower the firing temperature. On the other hand, in order to sinter the ceramics sintered body 36, it is necessary to perform firing at a predetermined temperature or higher for a predetermined time depending on the amount of additive contained in the granulated powder 32. Therefore, the firing time and firing temperature are adjusted according to the amount of additive contained in the granulated powder 32 .

In the removing process, after the uniaxial pressure firing, a predetermined area of the ceramic sintered body 36 formed on the metal member 10 is removed while leaving a predetermined thickness. In addition, a step of processing into a predetermined shape may be provided. At this time, depending on the design of the joined body 100, 200, part or all of the ceramic sintered body 36 formed on one main surface 12, the other main surface 14, or the side surface 16 of the metal member 10 may be removed to expose the metal member 10 . In the removing process, if the fired ceramics sintered body 36 has a thickness required for the insulating layer 30, the first ceramics member 40, or the second ceramics member 45, the removing process need not be performed. Further, a step of processing the shape of the metal member 10 may be provided. At this time, the metal member 10 is processed so that the maximum thickness in the direction perpendicular to one main surface 12 of the metal member 10 does not fall below 1 mm.

Further, when the electrode embedding member 250 is used, a step of exposing a part of the electrode 50 or a step of connecting a terminal to the electrode 50 may be provided.

In addition, in the method of forming and laminating the molded body, a process of degreasing the molded body to produce a degreased body and a process of calcining the degreased body to produce a calcined body may be provided. In that case, for example, the degreasing temperature is preferably 400° C. or higher and 800° C. or lower, and the degreasing time is preferably 1 hour or longer and 120 hours or shorter. The degreasing atmosphere is preferably an air atmosphere or a nitrogen atmosphere, more preferably an air atmosphere. Further, for example, the calcination temperature is preferably 1200° C. or more and 1700° C. or less, and the calcination time is preferably 0.5 hours or more and 12 hours or less. The calcining atmosphere is preferably a nitrogen or inert gas atmosphere, but may be a vacuum atmosphere.

7A to 7E are cross-sectional views schematically showing one stage of the manufacturing process of the manufacturing method according to the embodiment of the present invention. FIG. 7 shows an example of a manufacturing method using a metal member precursor 24 having through-holes 20 penetrating in the thickness direction, or grooves 22 on one principal surface 12, the other principal surface 14, or side surfaces 16. . Only differences from the manufacturing method described above will be described.

The metal member precursor 24 prepared in the filling lamination step preferably has a through hole 20 penetrating in the thickness direction, or a groove 22 on one main surface 12 , the other main surface 14 , or the side surface 16 . Moreover, in the filling and lamination step, it is preferable to fill the through holes 20 or the grooves 22 formed in the metal member precursor 24 with the granulated powder 32 or a compact formed from the granulated powder. By filling the through-hole 20 or the groove 22 with the granulated powder 32 or the like and firing it in this way, the inner surface of the through-hole 20 or the inside of the groove 22 is also pressed against the hydrostatic force, and the through-hole 20 The ceramic sintered body 36 can be directly bonded to the inner surface of the groove 22 or the groove 22 . In addition, the risk of defects occurring in the ceramics sintered body 36 after firing is reduced. In addition to the granulated powder 32 or a molded body formed from the granulated powder, a calcined body or fired body thereof may be filled.

Moreover, the removing process preferably includes a process of removing the ceramic sintered body 36 formed in the through-hole 20 or the groove 22 while leaving a predetermined thickness. As a result, the insulating layer 30 can be formed on the inner surface of the through-hole 20 or the surface including the groove 22, which has been difficult to directly bond, and the applications of the bonded bodies 100 and 200 are further expanded. In addition, by using a metal member precursor 24 having through-holes 20 penetrating in the thickness direction, or grooves 22 on one main surface 12, the other main surface 14, or side surfaces 16, a difficult-to-work high-melting-point metal can be processed in advance, and shapes for various structures can be produced more easily than processing after firing, and the applications of the joined bodies 100 and 200 are further expanded.

The through-holes 20 are used, for example, as holes for retrofitting power supply terminals for extracting electrodes, holes for supplying or sucking gas, and holes for lift pins for placing a substrate. The groove portion 22 is used, for example, as an installation groove for sealing members with peripheral members.

By such a method, it is possible to manufacture a joined body or an electrode-embedded member capable of enhancing electrical insulation and suppressing erosion and contamination of the joint surface of the metal member and the insulating layer.

[Example]
(Preparation of conjugate)
(Example 1)
5 wt % of Y ₂ O ₃ was added to the AlN raw material powder, and a binder (PVA), dispersant and solvent were added to prepare a slurry, and a granulated powder was granulated with a spray dryer. In addition, as a metal member precursor made of a high-melting-point metal, a plate-shaped Mo having a diameter of Φ50 mm, a thickness of 8 mm, and a groove portion having a width of 5 mm and a depth of 3 mm was provided in the middle portion in the thickness direction of the side surface.

Next, the granulated powder was filled in a carbon mold with a bottom and press-molded with a carbon punch to produce a compact having a diameter of 80 mm and a thickness of 10 mm. Next, a metal member precursor was prepared and placed on the compact.

Next, the gap between the carbon mold and the side surface of the metal member precursor was filled with granulated powder having the same composition. Next, the carbon mold was further filled with the granulated powder, and the metal member precursor was embedded therein. At this time, the metal member precursor was filled with granulated powder and molded with a carbon punch so that the thickness from the upper surface of the metal member precursor became 10 mm.

Then, with the carbon punch inserted in the carbon mold, uniaxial hot press firing was performed at a temperature of 1800° C., a pressure of 4 MPa, and an N ₂ atmosphere for 2 hours. As a result, a metal member made of Mo, which is a high-melting-point metal, could be embedded inside the AlN sintered body having a diameter of 80 mm. Next, the side surface of the joined body was removed along the cross section in the central axis direction from the side surface of the metal member until the thickness of the insulating layer became 1 mm. In addition, the insulating layer formed in the groove on the side surface of the metal member was removed leaving a thickness of 1 mm from the surface of the groove. In this way, the joined body of Example 1 was produced.

(Example 2)
Among the granulated powders of Example 1, the granulated powders for forming a molded body to be laminated on one main surface were AlN raw material powders containing 0.5 wt% Y ₂ O ₃ and 0.9 wt% TiN. A joined body of Example 2 was produced in the same process and under the same conditions as in Example 1, except that the additive was changed. The granulated powder forming the molded body to be laminated on the other main surface and the granulated powder filled in the gap between the carbon mold and the side surface of the metal member precursor were 5 wt. % Y ₂ O ₃ is added, which is the same as in Example 1.

(Example 3)
A bonded body of Example 3 was produced in the same process and under the same conditions as in Example 2, except that the metal member precursor of Example 2 was replaced with a member made of an alloy in which 0.4 wt% of Y ₂ O ₃ was added to Mo. bottom.

(Example 4)
A joined body of Example 4 was produced in the same process and under the same conditions as in Example 1, except that the metal member precursor of Example 1 was replaced with a member made of W.

(Example 5)
The joined body of Example 5 was produced in the same process and under the same conditions as in Example 2, except that the granulated powder for forming the molded body to be laminated on one main surface of the granulated powder of Example 2 was changed only to the AlN raw material powder. was made. The granulated powder forming the molded body to be laminated on the other main surface and the granulated powder filled in the gap between the carbon mold and the side surface of the metal member precursor were 5 wt. % Y ₂ O ₃ is added, which is the same as in Example 1.

(Example 6)
A joined body of Example 6 was produced in the same process and under the same conditions as in Example 1, except that the firing time in Example 1 was changed to 5 hours.

(Example 7)
Among the granulated powders of Example 2, the granulated powder for forming the molded body to be laminated on one main surface was changed to the AlN raw material powder to which Y ₂ O ₃ was added in an internal ratio of 7 wt%, and the temperature was 1800. C., a pressure of 4 MPa, and a _N2 atmosphere for 10 hours, except for uniaxial hot press sintering. The granulated powder forming the molded body to be laminated on the other main surface and the granulated powder filled in the gap between the carbon mold and the side surface of the metal member precursor were 5 wt. % Y ₂ O ₃ is added, which is the same as in Example 1.

(Comparative example 1)
An Al metal member having the same shape as in Example 1 was prepared, and instead of the insulating layer, a 100 μm-thick alumina film was formed on the side surface of the Al by plasma spraying.

(Evaluation of electrical insulation)
Mo was grounded, and a probe of an insulation resistance meter (DC 1000 V) was applied to 100 arbitrary points on the insulating layer or alumina film to evaluate the insulation resistance value. A resistance of 50 MΩ or more was regarded as a pass.

(Measurement result)
It was confirmed that all of the examples had an insulation resistance of 50 MΩ or more, indicating high electrical insulation. In Comparative Example 1, 7 out of 100 locations showed defective insulation, indicating insufficient electrical insulation. This is due to the fact that the thermal sprayed film is essentially porous, the non-flat areas such as the corners of uneven parts tend to have a particularly sparse structure, and it is difficult to form a film thick enough to ensure sufficient insulation. It is considered that this is because electrical insulation cannot be locally ensured due to the above reasons. On the other hand, since the insulating layer of the present invention is a sintered body, the porosity is smaller than that of the sprayed film, and it is easy to increase the thickness, so that it is easy to secure electrical insulation. It is considered to be

(Elemental analysis)
Next, with respect to the sample of Example 1, a cut surface perpendicular to the stacking direction was subjected to elemental analysis by EPMA and mapped. It was found that Y and O are present in the insulating layer and the ceramic member (AlN sintered body), but are present in greater amounts at the joint interface between the insulating layer or the ceramic member and the metal member. That is, at the joint interface between the insulating layer or the ceramic member and the metal member, the metal concentration and oxygen concentration that constitute the second phase of the ceramic sintered body are higher than the metal concentration and oxygen concentration inside the ceramic sintered body, respectively. confirmed to be large.

FIG. 8 is a schematic cross-sectional view obtained by vertically cutting the side surface of Example 1. FIG. Regarding the cross section of the same field of view, the result of elemental analysis by EPMA in advance and the mapping was combined with the difference in color tone of the SEM image. layer, an oxygen-rich AlN ceramic layer, a refractory metal Mo layer, a carbide layer containing carbonized Mo, and a Mo layer in this order. Moreover, it was found that the cross sections of Examples 2 and 5 also had the same structure, although the thickness of each layer was different.

The AlN ceramic layer and the oxygen-rich AlN ceramic layer showed no difference in color tone on the SEM image. In addition, the oxygen-rich AlN ceramic layers of Examples 1 and 2 contained more Y as well as O than the AlN ceramic layers located relatively far from the bonding interface. The oxygen-rich AlN ceramic layer of Example 5 contained a large amount of O. It should be noted that the AlN ceramic layer and the oxygen-rich AlN ceramic layer have portions in which the amounts of oxygen and the like are relatively different in the ceramic member, and it was not possible to distinguish them by a clear standard.

A carbide layer of refractory metal was formed at a distance from the bonding interface. It is believed that C for carbiding the refractory metal is derived from the raw material or mixed from the environment, but the reason why such a layer is formed at a position a little away from the bonding interface is unknown.

(Measurement of thickness of carbide layer)
The average thickness of the refractory metal carbide layer was measured on 1000x SEM images. As a result, Example 1 was 24 μm, Example 2 was 14 μm, Example 3 was 17 μm, Example 4 was 16 μm, Example 5 was 2 μm, Example 6 was 32 μm, and Example 7 was 36 μm. It was confirmed that the higher the amount of additive contained in the granulated powder or the longer the firing time, the thicker the carbide layer of the high-melting-point metal.

In the joined body of the present invention, the average thickness of the carbide layer of the high-melting-point metal formed at the joint interface between the ceramic sintered body and the metal member can be made sufficiently thin, so it is thought that the joint strength increases. In addition, in the bonded body of the present invention, oxygen is present at a high concentration at the bonding interface between the ceramic sintered body and the metal member, so there is a possibility that the high melting point metal and AlN are chemically bonded via oxygen. is considered to be high. When the ceramic sintered body contains a metal oxide that constitutes the second phase, not only oxygen but also the metal that constitutes the second phase of the ceramic sintered body is present at a high concentration at the bonding interface between the ceramic sintered body and the metal member. Since it exists, it is thought that this also contributes, but in such a bonded body, the addition of a metal oxide that constitutes the second phase to the raw material promotes carbide formation during uniaxial pressing. Since the average thickness of the carbide layer of the refractory metal has increased, the bond strength itself is considered to be reduced.

(Example 8)
Two φ12 mm through-holes (PCD. 40 mm, equidistant) were formed in the metal member precursor of Example 1. Then, the metal member precursor is placed on a molded body having a diameter of φ80 mm, and the through holes of the metal member precursor and the side surfaces of the metal member precursor are filled with granulated powder, and the thickness is greater than the upper surface of the metal member precursor. A joined body of Example 8 was produced in the same process and under the same conditions, except that the granulated powder was further filled so that the diameter became 10 mm and the Mo was embedded.

After firing the joined body of Example 8, removal processing was performed until the thickness of the ceramic sintered body formed on the side surface of the metal member became 1 mm. A hole of Φ8 mm was drilled coaxially with the hole. As a result, it was possible to provide an insulating sleeve (insulating layer) with a thickness of 2 mm bonded to Mo in the through hole.

(Example 9)
(Preparation of electrode embedded member)
In Example 9, a heater electrode was embedded in the AlN sintered body (ceramic member) positioned on the metal member precursor in the manufacturing method of Example 8 to produce a heater module that can be used in high-temperature processes.

The same granulated powder as in Example 1 was prepared. In addition, as a metal member precursor, an upper diameter φ298 mm, a thickness of 10 mm, a lower diameter φ298 mm, a thickness of 10 mm, a groove having a width of 5 mm and a depth of 5 mm in the middle part in the thickness direction, two positions at a radius of 20 mm from the center corresponding to the terminal hole A plate-shaped Mo with a through hole of Φ12 mm was prepared.

First, a heater laminate was produced. The granulated powder was filled in a bottomed carbon mold and press-molded with a carbon punch to prepare a compact having a diameter of Φ320 mm and a thickness of 8 mm. Next, a heater electrode was placed on the compact. The heater electrode is obtained by cutting Mo mesh (wire diameter 0.1 mm, mesh size #50, plain weave) into a predetermined pattern to match the resistance value of the heater electrode. Next, the carbon mold was further filled with the granulated powder, and the heater electrodes were embedded in the carbon mold to prepare a heater laminate. At this time, granulated powder was filled and a carbon punch was used to form the heater electrode so that the thickness was 8 mm from the upper surface of the heater electrode.

Next, a plate-like Mo was placed on the heater laminate to produce a laminate. In this manner, a heater laminate and a laminate in which plate-like Mo was laminated were produced.

Then, with the carbon punch inserted into the carbon mold, uniaxial hot press firing was performed at a temperature of 1800° C., a pressure of 4 MPa, and an N ₂ atmosphere for 4 hours. After firing, the outer shape was processed (Φ300 mm×18 mm). The drilling of terminal holes (Φ8 mm) for connecting the electrodes and an external power supply, the connection of the terminals, and the preparation of the necessary insulating structure were simultaneously performed during processing after firing. Thus, an electrode-embedded member of Example 9 was produced.

(evaluation)
The fabricated heater module could be heated to 400° C. by energizing the heater electrodes from an external power supply.

As described above, the bonded body or electrode-embedded member of the present invention can bond an insulating layer made of a ceramic sintered body containing AlN as a main component to a desired surface of a metal member that serves as a base such as a substrate holding member, thereby providing electrical insulation. It was confirmed that a conjugate with enhanced properties can be obtained. In addition, it was confirmed that the thick metal member can be used for various purposes, such as using the metal member as a heat sink. Moreover, it was confirmed that the manufacturing method of the present invention can manufacture such a bonded body or an electrode-embedded member.

It goes without saying that the present invention is not limited to the above-described embodiments, but extends to various modifications and equivalents within the spirit and scope of the present invention. Also, the structure, shape, number, position, size, etc. of the constituent elements shown in each drawing are for convenience of explanation, and may be changed as appropriate.

10 metal member 12 one main surface 14 the other main surface 16 side surface 20 through hole 22 groove 24 metal member precursor 30 insulating layer 32 granulated powder 34 laminate 36 ceramic sintered body 40 first ceramic member 45 second Ceramic member 50 Electrode 60 Carbon mold 70 Carbon punches 100 and 200 Joined body 250 Electrode embedded member

Claims (9)

A joined body of a metal member made of a high melting point metal having a melting point of 2000° C. or higher and an insulating layer made of a ceramic sintered body containing AlN as a main component,
The maximum thickness in a direction perpendicular to one main surface of the metal member is 1 mm or more,
The bonding, wherein the insulating layer is directly bonded to at least a part of the metal member except for two surfaces of the one main surface and the other main surface facing the one main surface. body. the metal member has a carbide layer containing a carbide of the refractory metal in the vicinity of the bonding interface between the metal member and the insulating layer;
2. A joined body according to claim 1, wherein said carbide layer has an average thickness of 40 [mu]m or less. The metal member has a through hole penetrating in the thickness direction, or a groove on one main surface, the other main surface, or a side surface,
3. The joined body according to claim 1, wherein the insulating layer is joined to the inner surface of the through hole or the surface including the groove. 4. The joined body according to claim 1, wherein the metal member contains 1 wt % or less of a second metal oxide, which is an oxide of a metal different from the refractory metal. 5. The method according to claim 1, wherein a first ceramic member made of a ceramic sintered body containing AlN as a main component is bonded to said one main surface of said metal member. zygote. 6. The joined body according to claim 5, wherein a second ceramic member made of a ceramic sintered body containing AlN as a main component is further joined to said other main surface of said metal member. a joined body according to claim 5;
and an electrode embedded in the first ceramic member of the joined body. A method for producing a joined body of a metal member made of a high melting point metal having a melting point of 2000° C. or higher and an insulating layer made of a ceramic sintered body containing AlN as a main component,
a preparation step of preparing a granulated powder obtained by granulating the AlN raw material powder or a powder obtained by adding a metal oxide raw material powder to the AlN raw material powder;
The granulated powder or a molded body formed from the granulated powder and a plate-shaped metal member precursor having a thickness of 1 mm or more made of the high-melting metal are arranged so that one main surface of the metal member precursor is perpendicular to the stacking direction. A filling lamination step of laminating so that the granulated powder or the molded body is filled in the gap between the side surface of the metal member precursor and the carbon mold, and
A laminate forming step of inserting a carbon punch into the carbon mold to form a laminate;
A sintering step of uniaxially pressurizing and sintering the laminate;
and a removing step of removing the ceramic sintered body formed in the metal member precursor after the uniaxial pressure firing while leaving a predetermined thickness. The metal member precursor has a through hole penetrating in the thickness direction, or a groove on one main surface, the other main surface, or a side surface,
9. The method of manufacturing a joined body according to claim 8, wherein said removing step includes a step of removing said ceramic sintered body formed in said through-hole or said groove while leaving a predetermined thickness.

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