Ceramic substrate and manufacturing method thereof, electrostatic chuck, substrate fixing device, semiconductor device package

Abstract

To provide a ceramic substrate in which a conductor pattern containing tungsten is sintered using a sintering aid different from conventional ones.SOLUTION: A ceramic substrate has a base and a conductor pattern embedded in the base. The base is ceramic. The conductor pattern primarily consists of a solid solution of a body-centered cubic lattice structure in which nickel and manganese are solidly dissolved in tungsten, a solid solution of a body-centered cubic lattice structure in which nickel and niobium are solidly dissolved in tungsten, or a solid solution of a body-centered cubic lattice structure in which nickel and indium are solidly dissolved in tungsten.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a ceramic substrate and a manufacturing method thereof, an electrostatic chuck, a substrate fixing device, and a package for a semiconductor device. [Background technology]

[0002] Conventionally, a film forming apparatus or a plasma etching apparatus used in manufacturing a semiconductor device has a stage for precisely holding a wafer in a vacuum processing chamber. As such a stage, for example, a substrate fixing device that attracts and holds a wafer by an electrostatic chuck mounted on a base plate has been proposed.

[0003] The electrostatic chuck is made of a ceramic substrate having a base body, an electrostatic electrode built into the base body, etc. The electrostatic electrode is, for example, a sintered body containing tungsten as a main component, nickel oxide, aluminum oxide, and silicon dioxide.

[0004] In the above sintered body, ceramics and tungsten are sintered under the same conditions, but tungsten is difficult to sinter due to its high melting point (3300°C or higher), and it is necessary to add an appropriate sintering aid. In the above sintered body, nickel oxide, aluminum oxide, and silicon dioxide function as sintering aids (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-43336 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, some of the materials that function as sintering aids for sintering tungsten are relatively difficult to obtain. Therefore, it is preferable to have many options for materials that function as sintering aids, and new sintering aids for sintering tungsten are needed.

[0007] The present invention has been made in view of the above-mentioned points, and has an object to provide a ceramic substrate in which a conductor pattern containing tungsten is sintered using a sintering aid different from that used in the past. [Means for solving the problem]

[0008] This ceramic substrate has a base and a conductive pattern embedded in the base, the base being made of ceramic, and the conductive pattern being mainly composed of a solid solution of nickel and manganese in tungsten with a body-centered cubic lattice structure, a solid solution of nickel and niobium in tungsten with a body-centered cubic lattice structure, or a solid solution of nickel and indium in tungsten with a body-centered cubic lattice structure. Effect of the Invention

[0009] According to the disclosed technique, it is possible to provide a ceramic substrate in which a conductor pattern containing tungsten is sintered using a sintering aid different from that used in the past. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view illustrating a simplified example of a substrate fixing device according to a first embodiment. [Diagram 2] FIG. 2 is a plan view illustrating in a simplified manner the substrate fixing device according to the first embodiment. [Diagram 3] 1A to 1C are perspective views illustrating a manufacturing process of the electrostatic chuck according to the first embodiment; [Figure 4] 6A to 6C are perspective views (part 2) illustrating the manufacturing process of the electrostatic chuck according to the first embodiment. [Diagram 5] 1 shows the results of investigation of the liquidus temperature in Example 1. [Figure 6] 1 shows the results of investigation of the liquidus temperature in Example 2. [Figure 7] 1 shows the results of investigation of the liquidus temperature in Example 3. [Figure 8] 1 shows the results of investigation of the liquidus temperature in Example 4. [Figure 9] 11 is a cross-sectional view illustrating a package for a semiconductor device according to a second embodiment. FIG. [Figure 10] 13 is a plan view illustrating a package for a semiconductor device according to a second embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and duplicated explanations may be omitted.

[0012] First embodiment [Structure of the substrate holding device] Fig. 1 is a cross-sectional view illustrating a substrate fixing device according to a first embodiment in a simplified manner. Referring to Fig. 1, the substrate fixing device 1 has, as its main components, a base plate 10 and an electrostatic chuck 20. The substrate fixing device 1 is a device that adsorbs and holds a substrate W (e.g., a semiconductor wafer or the like) that is an object to be adsorbed, by the electrostatic chuck 20.

[0013] The base plate 10 is a member for mounting the electrostatic chuck 20. The thickness of the base plate 10 is, for example, about 20 to 40 mm. The base plate 10 is formed from, for example, a metal material such as aluminum or cemented carbide, or a composite material of such a metal material and a ceramic material, and can be used as an electrode for controlling plasma. For example, in terms of availability, ease of processing, good thermal conductivity, etc., aluminum or an alloy thereof is used and the surface thereof is anodized (insulating layer formed).

[0014] For example, by supplying a predetermined high-frequency power to the base plate 10, the energy for causing the ions in the generated plasma state to collide with the substrate W attracted to the electrostatic chuck 20 can be controlled, thereby enabling the etching process to be performed effectively.

[0015] A gas supply path for introducing an inert gas for cooling the substrate W attracted to the electrostatic chuck 20 may be provided inside the base plate 10. When an inert gas such as He or Ar is introduced from the outside of the substrate fixing device 1 into the gas supply path and the inert gas is supplied to the back surface of the substrate W attracted to the electrostatic chuck 20, the substrate W can be cooled.

[0016] A coolant flow path may be provided inside the base plate 10. The coolant flow path is, for example, a hole formed in an annular shape inside the base plate 10. A coolant such as cooling water or Galden is introduced from the outside of the substrate fixing device 1 into the coolant flow path. By circulating the coolant through the coolant flow path to cool the base plate 10, the substrate W attracted to the electrostatic chuck 20 can be cooled.

[0017] The electrostatic chuck 20 is a part that attracts and holds the substrate W, which is an object to be attracted. The planar shape of the electrostatic chuck 20 is formed according to the shape of the substrate W, and is, for example, circular. The diameter of the wafer, which is an object to be attracted to the electrostatic chuck 20, is, for example, 8, 12, or 18 inches.

[0018] Note that a plan view refers to viewing the object from the normal direction of the upper surface 10a of the base plate 10, and a planar shape refers to the shape of the object viewed from the normal direction of the upper surface 10a of the base plate 10.

[0019] The electrostatic chuck 20 is provided on the upper surface 10a of the base plate 10 via an adhesive layer. The adhesive layer is, for example, a silicone adhesive. The adhesive layer has a thickness of, for example, about 0.1 to 2.0 mm. The adhesive layer bonds the base plate 10 and the electrostatic chuck 20 and has the effect of reducing stress caused by the difference in thermal expansion coefficient between the ceramic electrostatic chuck 20 and the aluminum base plate 10. The electrostatic chuck 20 may be fixed to the base plate 10 by screws.

[0020] The electrostatic chuck 20 is a ceramic substrate having, as its main components, a base 21, an electrostatic electrode 22, and a heating element 24. The upper surface of the base 21 is a mounting surface 21a on which an object to be attracted is placed. The electrostatic chuck 20 is, for example, a Johnsen-Rahbek type electrostatic chuck. However, the electrostatic chuck 20 may be a Coulomb force type electrostatic chuck.

[0021] The substrate 21 is a dielectric material. The thickness of the substrate 21 is, for example, about 5 to 10 mm, and the relative dielectric constant (1 kHz) of the substrate 21 is, for example, about 9 to 10. The substrate 21 has an insulation resistivity of 10 at 300° C. 14 It is preferable that the resistivity is Ωcm or more.

[0022] The substrate 21 is made of ceramics containing aluminum oxide (Al2O3) and yttrium aluminum garnet (YAG) as main components, for example.

[0023] The substrate 21 is preferably made of aluminum oxide ceramics containing 10 to 80 mole percent of an yttrium aluminum garnet phase (YAG phase). This allows the insulation resistivity of the substrate 21 at 300° C. to be increased to 10 14 It can be made to be Ωcm or more.

[0024] The substrate 21 may be made of aluminum oxide ceramics having an aluminum oxide purity of 99 weight percent or more. This allows the insulation resistivity of the substrate 21 at 300° C. to be increased to 10 14The resistivity can be Ωcm or more. A purity of 99% or more indicates that the material is formed without adding a sintering aid. A purity of 99% or more also means that the material may contain impurities unintentionally present in the manufacturing process or the like. The base 21 preferably has a relative density of 97% or more with respect to aluminum oxide. In order to enhance sinterability, it is preferable that the average particle diameter of aluminum oxide in the base 21 is 1.0 μm or less.

[0025] The electrostatic electrode 22 is a thin-film electrode formed by a conductor pattern, and is built into the base 21. In this embodiment, the electrostatic electrode 22 is a bipolar type, and has a first electrostatic electrode 22a and a second electrostatic electrode 22b. Note that a monopolar type consisting of one electrostatic electrode may also be used as the electrostatic electrode 22.

[0026] The electrostatic electrode 22 mainly contains, for example, a solid solution of nickel and manganese in tungsten with a body-centered cubic lattice structure. The electrostatic electrode 22 may mainly contain a solid solution of nickel and niobium in tungsten with a body-centered cubic lattice structure. The electrostatic electrode 22 may mainly contain a solid solution of nickel and indium in tungsten with a body-centered cubic lattice structure.

[0027] The electrostatic electrode 22 may be mainly composed of a solid solution having a body-centered cubic lattice structure in which nickel, manganese, and a predetermined element are dissolved in tungsten, in which case the predetermined element is boron, magnesium, scandium, vanadium, chromium, iron, zinc, gallium, germanium, strontium, zirconium, niobium, molybdenum, or barium.

[0028] The electrostatic electrode 22 may be mainly composed of a solid solution having a body-centered cubic lattice structure in which nickel, niobium, and a predetermined element are dissolved in tungsten, in which case the predetermined element is boron, magnesium, calcium, scandium, titanium, vanadium, chromium, manganese, iron, zinc, gallium, germanium, strontium, zirconium, molybdenum, indium, or barium.

[0029] The electrostatic electrode 22 may be mainly composed of a solid solution having a body-centered cubic lattice structure in which nickel, indium, and a specific element are dissolved in tungsten as a solid solution, in which case the specific element is magnesium, calcium, scandium, titanium, vanadium, chromium, zinc, gallium, germanium, strontium, zirconium, niobium, molybdenum, or barium.

[0030] Here, the term "main component" refers to a component that accounts for 50 wt% or more of the total material constituting the electrostatic electrode 22. In the electrostatic electrode 22, the ratio of nickel and manganese to tungsten is preferably 0.05 wt% or more and 10 wt% or less. The same is true for nickel and niobium, or nickel and indium, and the ratio of each to tungsten is preferably 0.05 wt% or more and 10 wt% or less. In addition, the ratio of the above-mentioned specified elements to tungsten is preferably 0.05 wt% or more and 10 wt% or less.

[0031] The first electrostatic electrode 22a is connected to the positive electrode of a power source 40a provided outside the substrate fixing device 1. The second electrostatic electrode 22b is connected to the negative electrode of a power source 40b provided outside the substrate fixing device 1. The negative electrode of the power source 40a and the positive electrode of the power source 40b are connected outside the substrate fixing device 1, and the connection point is at ground potential.

[0032] A positive (+) voltage is applied to the first electrostatic electrode 22a from the power source 40a, and a negative (-) voltage is applied to the second electrostatic electrode 22b from the power source 40b. As a result, the first electrostatic electrode 22a is charged with a positive (+) charge, and the second electrostatic electrode 22b is charged with a negative (-) charge. Accordingly, a negative (-) charge is induced in a portion Wa of the substrate W corresponding to the first electrostatic electrode 22a, and a positive (+) charge is induced in a portion Wb of the substrate W corresponding to the second electrostatic electrode 22b.

[0033] When the substrate W, the electrostatic electrode 22, and the ceramic part 25 of the electrostatic chuck 20 (base 21) disposed therebetween are regarded as a capacitor, the ceramic part 25 corresponds to a dielectric layer. The substrate W is electrostatically attracted onto the electrostatic chuck 20 by the Coulomb force generated between the electrostatic electrode 22 and the substrate W via the ceramic part 25. The attracting and holding force becomes stronger as the voltage applied to the electrostatic electrode 22 becomes higher.

[0034] The heating element 24 is a heater built into the base 21, which generates heat when a current flows therethrough to heat the mounting surface 21a of the base 21 to a predetermined temperature. The heating element 24 is disposed below (on the base plate 10 side of) the first electrostatic electrode 22a and the second electrostatic electrode 22b. The heating element 24 is a conductor formed in a film shape. The heating element 24 is provided as a plurality of heater electrodes capable of independently controlling the heating of a plurality of regions (heater zones) on the base 21 in a plane. The heating element 24 may be provided as a single heater electrode. The heating element 24 can be formed, for example, from the same material as the electrostatic electrode 22.

[0035] When a current is supplied to the heating element 24 from a power source provided outside the substrate fixing device 1, the heating element 24 generates heat and heats the electrostatic chuck 20. The temperature of the substrate W is controlled to a predetermined temperature by the temperature of the electrostatic chuck 20. The heating temperature of the electrostatic chuck 20 is set within a range of 50°C to 200°C, for example, to 150°C.

[0036] Fig. 2 is a plan view illustrating a simplified example of the substrate fixing device according to the first embodiment. Referring to Fig. 2, in the substrate fixing device 1, an electrostatic chuck 20 is disposed on a disk-shaped base plate 10, and the peripheral portion of the base plate 10 is exposed around the electrostatic chuck 20. Mounting holes 11 for mounting the base plate 10 to a chamber of a semiconductor manufacturing device are arranged along the peripheral portion.

[0037] Moreover, the electrostatic chuck 20 and the base plate 10 have a plurality of (three in FIG. 2) lift pin openings 12 in the center. Lift pins for moving the substrate W in the vertical direction are inserted into the lift pin openings 12. By lifting the substrate W above the placement surface 21a with the lift pins, the substrate W can be automatically transported by a transport device.

[0038] [Electrostatic chuck manufacturing method] Next, a description will be given of a manufacturing method of the electrostatic chuck 20. Figures 3 and 4 are perspective views illustrating the manufacturing process of the electrostatic chuck according to the first embodiment.

[0039] First, as shown in Fig. 3(a), a green sheet 51 made of a ceramic material and an organic material is prepared. The green sheet 51 is formed, for example, into a rectangular plate shape. The ceramic material of the green sheet 51 is made of aluminum oxide and does not contain a sintering aid. The organic components are removed from the green sheet 51, and the ceramic material is sintered and densified, becoming the base 21 on which the substrate W shown in Fig. 1 is mounted.

[0040] 3(b), a green sheet 52 made of the same material and shape as the green sheet 51 is prepared, and a conductive paste is printed on the upper surface of the green sheet 52 by, for example, a printing method (screen printing) to form a conductor pattern 55. The conductor pattern 55 becomes the electrostatic electrode 22 shown in FIG. 1 by firing in a process described later. The conductor pattern 55 may be formed on the lower surface of the green sheet 51.

[0041] Conductive paste in which nickel oxide and manganese oxide are added to tungsten, conductive paste in which nickel oxide and niobium oxide are added to tungsten, or conductive paste in which nickel oxide and indium oxide are added to tungsten is used to form the conductor pattern 55. The conductive paste used to form the conductor pattern 55 may further contain the above-mentioned predetermined elements. In addition, the conductive paste used to form the conductor pattern 55 may further contain an organic material, etc.

[0042] The amount of nickel oxide and manganese oxide added is preferably, for example, 0.1 g to 10 g per 100 g of tungsten. That is, in the conductive paste, the ratio of nickel oxide and manganese oxide to tungsten is preferably 0.1 wt% to 10 wt%. When the ratio of nickel oxide and manganese oxide to tungsten is 0.1 wt% or more, the liquid phase temperature of the conductive paste can be 1450° C. or less. The same applies to nickel oxide and niobium oxide, and nickel oxide and indium oxide, and the ratio of each to tungsten is preferably 0.1 wt% to 10 wt%.

[0043] Even if the ratio of nickel oxide and manganese oxide, nickel oxide and niobium oxide, or nickel oxide and indium oxide to tungsten is more than 10 wt%, the liquid phase temperature of the conductive paste is still 1450°C or less. However, if the ratio of nickel oxide and manganese oxide, nickel oxide and niobium oxide, or nickel oxide and indium oxide to tungsten is more than 10 wt%, the electrical characteristics of tungsten are difficult to exhibit in the solid solution containing tungsten produced by sintering the conductive paste. Therefore, it is preferable that the ratio of nickel oxide and manganese oxide, nickel oxide and niobium oxide, or nickel oxide and indium oxide to tungsten is 10 wt% or less. In addition, when the conductive paste and the green sheet are simultaneously fired, the average particle size of tungsten is preferably 0.5 μm or more and 3.0 μm or less.

[0044] Next, as shown in FIG. 3(c), a green sheet 53 made of the same material and shape as the green sheet 51 is prepared, and a conductive paste is printed on the upper surface of the green sheet 53 by, for example, a printing method (screen printing) to form a conductive pattern 57. The conductive paste for forming the conductive pattern 57 may be a conductive paste made of the same material as the conductive paste for forming the above-mentioned conductive pattern 55. The green sheet 53 is for forming the heating element 24 shown in FIG. 1 by firing, and becomes the base 21 of the portion bonded to the base plate 10. The conductive pattern 57 becomes the heating element 24 by firing in a process described later. The conductive pattern 57 may be formed on the lower surface of the above-mentioned green sheet 52.

[0045] Next, as shown in Fig. 4(a), the green sheets 51-53 are laminated to form a structure 71a. The green sheets 51-53 are bonded to each other by applying pressure while heating. Next, as shown in Fig. 4(b), the periphery of the structure 71a is cut to form a disk-shaped structure 71b.

[0046] Next, the structure 71b shown in FIG. 4(b) is fired to obtain the ceramic substrate 72a shown in FIG. 4(c). The firing temperature is, for example, 1600° C. In this process, the electrostatic electrode 22 is obtained by sintering the conductive pattern 55, and the heating element 24 is obtained by sintering the conductive pattern 57. The liquid phase temperature of the conductive paste in which nickel oxide and manganese oxide, nickel oxide and niobium oxide, or nickel oxide and indium oxide are added to tungsten is 1450° C. or less, so that it is easily sintered at the temperature (for example, 1600° C.) when firing the ceramic substrate 72a. As a result, the electrostatic electrode 22 and the heating element 24 are formed, which are mainly composed of a solid solution of a body-centered cubic lattice structure in which nickel and manganese, nickel and niobium, or nickel and indium are solid-dissolved in tungsten.

[0047] Tungsten is sintered between the liquid phase temperature of the conductive paste and the temperature (e.g., 1600°C) when the ceramic substrate 72a is fired. If this temperature range is narrow, the tungsten cannot be sintered sufficiently. Therefore, the liquid phase temperature is preferably 1450°C or lower. If the liquid phase temperature is 1450°C or lower, the tungsten can be sintered sufficiently.

[0048] On the other hand, the liquidus temperature of the conductive paste should not be too low. If the temperature range from the liquidus temperature to the temperature (e.g., 1600°C) at which the ceramic substrate 72a is fired becomes wide, there is a high possibility that the tungsten will be burned too much and become oversintered. If the tungsten becomes oversintered, the adhesion with the ceramics will decrease. Therefore, it is preferable that the liquidus temperature is 1390°C or higher. If the liquidus temperature is 1390°C or higher, the possibility that the tungsten will become oversintered can be reduced.

[0049] Next, various processes are performed on the ceramic substrate 72a to complete the electrostatic chuck 20. For example, both the top and bottom surfaces of the ceramic substrate 72a are polished to form a mounting surface and an adhesive surface. Also, the openings 12 for lift pins shown in FIG. 1 are formed in the ceramic substrate 72a.

[0050] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0051] [Consideration of liquid phase temperature] In Example 1, 1 g of nickel oxide and 1 g of manganese oxide were added to 100 g of tungsten, and the liquidus temperature was calculated using Fact Sage (manufactured by Computational Mechanics Research Center, Inc.) when the mixture was adjusted in an atmosphere of nitrogen and hydrogen. Fact Sage is software that quantitatively predicts the thermodynamic equilibrium state of a multi-component system.

[0052] The calculation results of Example 1 are shown in Figure 5. As shown in Figure 5, it was confirmed by calculation that a solid solution having a body-centered cubic lattice structure in which nickel and manganese are dissolved in tungsten is formed by sintering the material according to Example 1. In addition, in Example 1, the liquidus temperature was about 1440°C.

[0053] Next, as Example 2, 1 g of nickel oxide and 1 g of niobium oxide were added to 100 g of tungsten, and the liquidus temperature was calculated using Fact Sage when adjustment was performed in an atmosphere of nitrogen and hydrogen.

[0054] The calculation results of Example 2 are shown in Figure 6. As shown in Figure 6, it was confirmed by calculation that a solid solution having a body-centered cubic lattice structure in which nickel and niobium are dissolved in tungsten is formed by sintering the material according to Example 2. In addition, in Example 2, the liquidus temperature was about 1450°C.

[0055] Next, as Example 3, 1 g of nickel oxide and 1 g of indium oxide were added to 100 g of tungsten, and the liquidus temperature was calculated by Fact Sage when the mixture was adjusted in an atmosphere of nitrogen and hydrogen.

[0056] The calculation results of Example 3 are shown in Figure 7. As shown in Figure 7, it was confirmed by calculation that a solid solution having a body-centered cubic lattice structure in which nickel and indium are dissolved in tungsten is formed by sintering the material according to Example 3. In addition, in Example 3, the liquidus temperature was about 1430°C.

[0057] In this way, when nickel oxide and manganese oxide, nickel oxide and niobium oxide, or nickel oxide and indium oxide are added to tungsten and sintered, the liquidus temperature can be set to about 1430° C. to 1450° C. This temperature is sufficiently lower than the melting point of tungsten (3300° C. or higher) and is lower than the sintering temperature of the base (for example, about 1500° C. to 1600° C.), so tungsten can be easily sintered.

[0058] That is, nickel oxide and manganese oxide, nickel oxide and niobium oxide, and nickel oxide and indium oxide are useful as sintering aids different from conventional ones used when sintering a conductor pattern containing tungsten on a ceramic substrate.

[0059] Next, as Example 4, in Examples 1 to 3, a predetermined element was further added, and adjustment was performed in an atmosphere of nitrogen and hydrogen, and the liquidus temperature was calculated by Fact Sage.

[0060] For example, when 1g of nickel oxide, 1g of manganese oxide, and 1g of boron oxide were added to 100g of tungsten and adjusted in an atmosphere of nitrogen and hydrogen, the liquidus temperature was calculated using Fact Sage and found to be approximately 1410°C.

[0061] In addition, when 1g of nickel oxide, 1g of niobium oxide, and 1g of iron oxide were added to 100g of tungsten and adjusted in an atmosphere of nitrogen and hydrogen, the liquidus temperature was calculated using Fact Sage and found to be approximately 1420°C.

[0062] In addition, when 1g of nickel oxide, 1g of indium oxide, and 1g of gallium oxide were added to 100g of tungsten and adjusted in an atmosphere of nitrogen and hydrogen, the liquidus temperature was calculated using Fact Sage and found to be approximately 1410°C.

[0063] In addition, when 1g of nickel oxide, 1g of niobium oxide, and 1g of indium oxide were added to 100g of tungsten and adjusted in an atmosphere of nitrogen and hydrogen, the liquidus temperature was calculated using Fact Sage and found to be approximately 1390°C.

[0064] Including these results, the liquidus temperature calculated by the inventors using Fact Sage is summarized in Figure 8. Figure 8 shows the liquidus temperature when oxides of elements shown in the vertical and horizontal directions are added to tungsten together with nickel oxide. It can be seen from Figure 8 that, for example, by adding nickel oxide, manganese oxide, and boron oxide to tungsten, the liquidus temperature can be increased to approximately 1410°C.

[0065] As shown in the region enclosed by the rough dashed line in Fig. 8, the liquidus temperature can be adjusted to a range of about 1410°C to 1450°C by adding nickel oxide, manganese oxide, and a predetermined element to tungsten. Then, by firing, it is possible to form a conductor pattern mainly composed of a solid solution of nickel, manganese, and a predetermined element in tungsten with a body-centered cubic lattice structure. The predetermined element in this case is boron, magnesium, scandium, vanadium, chromium, iron, zinc, gallium, germanium, strontium, zirconium, niobium, molybdenum, or barium.

[0066] As shown in the region surrounded by a solid line in Fig. 8, the liquidus temperature can be adjusted to a range of about 1390°C to 1450°C by adding nickel oxide, niobium oxide, and a predetermined element to tungsten. Then, by firing, it is possible to form a conductor pattern mainly composed of a solid solution of nickel, niobium, and a predetermined element in tungsten with a body-centered cubic lattice structure. The predetermined element in this case is boron, magnesium, calcium, scandium, titanium, vanadium, chromium, manganese, iron, zinc, gallium, germanium, strontium, zirconium, molybdenum, indium, or barium.

[0067] As shown in the area surrounded by the fine dashed line in Fig. 8, the liquidus temperature can be adjusted to a range of about 1390°C to 1450°C by adding nickel oxide, indium oxide, and a predetermined element to tungsten. Then, by firing, it is possible to form a conductor pattern mainly composed of a solid solution of nickel, indium, and a predetermined element in tungsten with a body-centered cubic lattice structure. The predetermined element in this case is magnesium, calcium, scandium, titanium, vanadium, chromium, zinc, gallium, germanium, strontium, zirconium, niobium, molybdenum, or barium.

[0068] In particular, when nickel oxide, niobium oxide, and indium oxide are added to tungsten, the liquidus temperature can be increased to approximately 1390°C, which is effective when it is desired to lower the liquidus temperature.

[0069] Second Embodiment In the second embodiment, an example of a package for a semiconductor device having the ceramic substrate described in the first embodiment is shown. Fig. 9 is a cross-sectional view illustrating the package for a semiconductor device according to the second embodiment. Fig. 10 is a plan view illustrating the package for a semiconductor device according to the second embodiment.

[0070] As shown in FIG. 9, the semiconductor device package 100 has a ceramic substrate 110, a heat sink 150, and external connection terminals 160, and the heat sink 150 is brazed to the ceramic substrate 110.

[0071] The ceramic substrate 110 has a plurality of laminated ceramic bases 111, 112, 113, and 114 (four in this embodiment), wiring patterns 121, 122, 123, and 124 which are an example of a conductor pattern, and vias 132, 133, and 134 which penetrate the ceramic bases 112, 113, and 114. The via 132 connects the wiring patterns 121 and 122 to each other, the via 133 connects the wiring patterns 122 and 123 to each other, and the via 134 connects the wiring patterns 123 and 124 to each other. In the ceramic substrate 110, the ceramic bases 111 to 114 form a base.

[0072] 8 and 9, the ceramic substrate 110 is provided with a cavity 170 that penetrates the center of the ceramic bases 112, 113, and 114 and in which the semiconductor element 200 is mounted. The wiring pattern 121 is disposed on the upper surface of the ceramic base 112 so as to surround the cavity 170. The ceramic base 111 is provided with an opening 111X that exposes the wiring pattern 121.

[0073] The ceramic bases 111-114 are ceramics made of aluminum oxide, and the wiring patterns 121-124 are mainly composed of a solid solution of nickel and manganese in tungsten with a body-centered cubic lattice structure, a solid solution of nickel and niobium in tungsten with a body-centered cubic lattice structure, or a solid solution of nickel and indium in tungsten with a body-centered cubic lattice structure. The wiring patterns 121-124 may further contain the above-mentioned predetermined elements. The vias 132-134 are sintered bodies mainly composed of molybdenum, nickel oxide, aluminum oxide, and silicon dioxide. The ceramic substrate 110 can be manufactured by the same manufacturing method as that of the electrostatic chuck 20 of the first embodiment.

[0074] In the semiconductor device package 100, the semiconductor element 200 is mounted on a heat sink 150. Pads of the semiconductor element 200 are electrically connected to the wiring pattern 121 of the ceramic substrate 110 by bonding wires or the like. As a result, the semiconductor element 200 is connected to the external connection terminal 160 through the wiring patterns 121-124 and the vias 132-134.

[0075] In the semiconductor device package 100, the wiring patterns 121 to 124 can be formed by sintering a conductive paste in which nickel oxide and manganese oxide are added to tungsten, a conductive paste in which nickel oxide and niobium oxide are added to tungsten, or a conductive paste in which nickel oxide and indium oxide are added to tungsten. The conductive paste may further contain the above-mentioned predetermined elements. This allows tungsten to be easily sintered, as in the first embodiment.

[0076] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0077] For example, in the first embodiment, the members included in the substrate fixing device and their arrangement may be changed as appropriate.

[0078] Also, in the first embodiment, the heating element 24 may be disposed between the electrostatic chuck 20 and the base plate 10. Also, the heating element 24 may be provided inside the base plate 10. Also, the heating element 24 may be attached externally below the electrostatic chuck.

[0079] Moreover, the substrate fixing device according to the first embodiment is applied to a semiconductor manufacturing device, for example, a dry etching device (for example, a parallel plate type reactive ion etching (RIE: Reactive Ion Etching) device).

[0080] Moreover, examples of objects to be attracted by the substrate fixing device according to the first embodiment include glass substrates used in the manufacturing process of liquid crystal panels and the like, in addition to semiconductor wafers (silicon wafers and the like). [Explanation of symbols]

[0081] 1 Board fixing device 10 Base plate 11 Mounting hole 12 Lift pin opening 20 Electrostatic Chuck 21 Base 22 Electrostatic Electrode 22a First electrostatic electrode 22b Second electrostatic electrode 24 Heating element 25 Ceramics Department 40a, 40b power supply 51, 52, 53 Green Sheets 55, 57 Conductor pattern 71a, 71b structure 72a Ceramic substrate 100 Semiconductor device package 110 Ceramic Substrate 111~114 Ceramic substrate 121~124 Wiring pattern 132~134 via

Claims

1. A substrate; A conductive pattern embedded in the substrate, The substrate is made of ceramics, The conductor pattern is a ceramic substrate whose main component is a solid solution of nickel and manganese in tungsten having a body-centered cubic lattice structure, a solid solution of nickel and niobium in tungsten having a body-centered cubic lattice structure, or a solid solution of nickel and indium in tungsten having a body-centered cubic lattice structure.

2. The conductive pattern is mainly composed of a solid solution having a body-centered cubic lattice structure in which nickel, manganese, and a predetermined element are solid-dissolved in tungsten, 2. The ceramic substrate according to claim 1, wherein the predetermined element is boron, magnesium, scandium, vanadium, chromium, iron, zinc, gallium, germanium, strontium, zirconium, niobium, molybdenum, or barium.

3. The conductive pattern is mainly composed of a solid solution having a body-centered cubic lattice structure in which nickel, niobium, and a predetermined element are solid-dissolved in tungsten, 2. The ceramic substrate according to claim 1, wherein the predetermined element is boron, magnesium, calcium, scandium, titanium, vanadium, chromium, manganese, iron, zinc, gallium, germanium, strontium, zirconium, molybdenum, indium, or barium.

4. The conductive pattern is mainly composed of a solid solution having a body-centered cubic lattice structure in which nickel, indium, and a predetermined element are solid-dissolved in tungsten, 2. The ceramic substrate according to claim 1, wherein the predetermined element is magnesium, calcium, scandium, titanium, vanadium, chromium, zinc, gallium, germanium, strontium, zirconium, niobium, molybdenum, or barium.

5. 5. The ceramic substrate according to claim 1, wherein the base is an aluminum oxide ceramic containing an yttrium aluminum garnet phase.

6. 5. The ceramic substrate according to claim 1, wherein the base is an aluminum oxide ceramic having an aluminum oxide purity of 99 weight percent or more.

7. A package for a semiconductor device, comprising the ceramic substrate according to claim 1 .

8. 5. The electrostatic chuck according to claim 1, wherein the conductive pattern is an electrostatic electrode.

9. A base plate; A substrate fixing device comprising: an electrostatic chuck according to claim 8 mounted on one surface of the base plate.

10. A method for manufacturing a ceramic substrate having a base and a conductor pattern embedded in the base, comprising the steps of: forming a conductor pattern on the upper surface of the green sheet using a conductive paste in which nickel oxide and manganese oxide are added to tungsten, a conductive paste in which nickel oxide and niobium oxide are added to tungsten, or a conductive paste in which nickel oxide and indium oxide are added to tungsten; and firing the green sheet and the conductor pattern to form the base and the conductor pattern.

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