Composite and manufacturing method thereof

Abstract

To provide a composite having excellent structural stability which comprises a middle layer (stabilization layer) that suppresses a problem such as chemical reaction and element diffusion, which could occur between two materials in the case where two portions including inorganic materials having constitutions different from each other bond, between the two materials, and a method for manufacturing the composite.SOLUTION: A structure 1 of the present invention comprises: a first material part 10 including a first inorganic material; a second material part 12 including a second inorganic material having a different constitution from the first inorganic material; and a stabilization layer 14 arranged between the first material part 10 and the second material part 12, where the stabilization layer 14 includes a compound expressed by M12M2O4 (in the formula, M1 and M2 are elements different from each other, M1 is at least one selected from Al, Fe and Ga, and M2 is at least one selected from Cu, Mg, Zn, Fe, Mn and Co ).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a composite having excellent structural stability and a method for producing the same. [Background technology]

[0002] In recent years, with the advancement of the IoT society, materials with various excellent properties, such as mechanical strength, thermal conductivity, and electrical and chemical properties, have been developed, and the development of devices incorporating multiple materials is progressing. Further development of novel materials and devices is expected in the future. For example, at the interface between materials with different chemical properties, such as oxides and nitrides, or at the interface between highly reactive materials, it is necessary to suppress chemical reactions and element diffusion, prevent material decomposition and degradation, and maintain the original performance of the materials. Therefore, in the development of new devices, it is necessary to suppress the insufficient mechanical strength at the interface between different materials and the degradation and decomposition of materials due to element diffusion that occurs during device fabrication and operation. To address these issues, intermediate layers and manufacturing methods tailored to each device or material combination are being developed.

[0003] For example, Patent Document 1 discloses a metal / ceramic bonded body used as a thermistor, in which a composite ceramic containing SiC is bonded to a surface layer made of an Fe-Cr-Al alloy, and the intermediate layer is made of Cr or a Cr alloy to suppress oxidation and peeling of the surface layer.

[0004] Patent Document 2 discloses a diffusion prevention layer that, in a surface acoustic wave device, when a substrate made of a piezoelectric material such as lithium tantalate or lithium niobate is bonded to a support substrate such as sapphire with an intervening layer provided therebetween, prevents oxygen contained in the intervening layer or the support substrate from diffusing into the piezoelectric material such as lithium tantalate or lithium niobate through heat treatment.

[0005] Patent Document 3 discloses a method for producing a metallized ceramic substrate in which a conductor layer is formed on a ceramic substrate directly or indirectly by firing conductive metal particles, and the ceramic substrate and the conductor layer are adhered to each other with high adhesion. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-182667 A [Patent Document 2] JP 2020-36212 A [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-109062 Summary of the Invention [Problem to be solved by the invention]

[0007] The object of the present invention is to provide a composite having excellent structural stability, which has an intermediate layer (stabilizing layer) between two materials that suppresses defects such as chemical reactions and element diffusion that may occur between the two materials when the two parts containing inorganic materials of different compositions are bonded, and a method for producing the composite. [Means for solving the problem]

[0008] As a result of extensive research, the present inventors have discovered that the above-mentioned object can be achieved by interposing a compound represented by the following general formula (1) between two material portions (stabilizing layer), and have thus completed the present invention.

[0009] [1] A composite comprising: a first material part containing a first inorganic material; a second material part containing a second inorganic material having a different composition from the first inorganic material; and a stabilizing layer disposed between the first material part and the second material part, The composite is characterized in that the stabilizing layer contains a compound (A) represented by the following general formula (1): M 1 2M 2 O4(1) (In the formula, M 1 and M 2 are different elements, and M 1 is at least one selected from Al, Fe, and Ga, and M 2 is at least one selected from Cu, Mg, Zn, Fe, Mn, and Co.

[0010] [2] The composite according to [1] above, wherein the first inorganic material contains a nitride, and the second inorganic material contains an oxide (excluding the compound (A)).

[0011] [3] The composite according to [1] above, wherein the first inorganic material contains a silicon compound (excluding silicon nitride) or silicon, and the second inorganic material contains an oxide (excluding compound (A)).

[0012] [4] The composite according to any one of [1] to [3] above, wherein the compound (A) is Al2CuO4.

[0013] [5] The composite according to any one of [1] to [4] above, wherein the stabilizing layer comprises a reinforcing layer containing an inorganic compound (excluding the compound (A)).

[0014] [6] The composite according to [5] above, wherein the inorganic compound contained in the reinforcing layer contains copper oxide.

[0015] [7] A method for producing the composite according to any one of [1] to [4] above, A method for producing a composite, comprising forming a film containing compound (A) on the surface of the first material part to form a laminate, and then forming the second material part on the surface of the film containing compound (A) in the laminate.

[0016] [8] The method for producing a composite according to [7] above, wherein the laminate is obtained by applying a paste containing a raw material for producing the compound (A) and a dispersion medium to the surface of the first material part, heating the formed coating film to remove the dispersion medium, and then further increasing the temperature to produce the compound (A) and form the compound (A)-containing film. [Effects of the Invention]

[0017] The composite of the present invention has excellent structural stability because it includes a stabilization layer between the first material portion and the second material portion that suppresses defects such as chemical reactions and element diffusion that may occur between two different materials when two material portions (first material portion and second material portion) containing inorganic materials of different compositions are bonded. In particular, the stabilization layer-side interface of the first material portion and the stabilization layer-side interface of the second material portion are free of defects, resulting in excellent structural stability. For example, when the first inorganic material contains a nitride, a silicon compound, or silicon, and the second inorganic material contains an oxide other than compound (A), chemical reactions and element diffusion that may occur between the first inorganic material and the second inorganic material when they are directly bonded can be suppressed. In the composite of the present invention, even when the stabilizing layer is provided with a reinforcing layer containing an inorganic compound other than the compound (A), the structural stability is excellent. According to the method for producing a composite of the present invention, a composite having the above-mentioned effects can be produced efficiently. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a first embodiment of the composite of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing a second embodiment of the composite of the present invention. [Figure 3] FIG. 2 is a schematic cross-sectional view showing a third embodiment of the composite of the present invention. [Figure 4] 1 shows an X-ray diffraction pattern of a stabilizing film (Al 2 CuO 4 film) formed on the surface of a silicon nitride substrate in a laminate obtained before producing a composite (C1) in Example 1. [Figure 5]1 is an X-ray diffraction pattern of a conductive sintered oxide film in the composite (C1) obtained in Example 1. [Figure 6] 1 is a cross-sectional SEM image of the composite (C1) obtained in Example 1. [Figure 7] 1 shows an X-ray diffraction pattern of a conductive sintered oxide film in a composite (D1) obtained in Comparative Example 1. [Figure 8] 1 shows an X-ray diffraction pattern of a conductive sintered oxide film in a composite (C2) obtained in Example 2. [Figure 9] 1 shows an X-ray diffraction pattern of a conductive sintered oxide film in a composite (D2) obtained in Comparative Example 2. [Figure 10] 1 shows an X-ray diffraction pattern of a conductive sintered oxide film in a composite (C3) obtained in Example 3. [Figure 11] 1 is a cross-sectional SEM image of the composite (C3) obtained in Example 3. [Figure 12] 1 shows an X-ray diffraction pattern of a SmBa2Cu3Oy sintered film in the composite (C4) obtained in Example 4. [Figure 13] 1 shows an X-ray diffraction pattern of the sintered surface of a composite (D3) obtained by sintering a SmBa2Cu3Oy printed film in Comparative Example 4. [Figure 14] 10 is an X-ray diffraction pattern of a stabilizing film (Al2O3-containing Al2CuO4 film) formed on the surface of a silicon nitride substrate in a laminate obtained before producing a composite (C5) in Example 5. [Figure 15] 1 shows an X-ray diffraction pattern of a conductive sintered oxide film in a composite (C5) obtained in Example 5. [Figure 16] 1 is a cross-sectional SEM image of the composite (C6) obtained in Example 6. [Figure 17] 1 shows an X-ray diffraction pattern of a conductive sintered oxide film in a composite (C6) obtained in Example 6. [Figure 18] 1 shows an X-ray diffraction pattern of a conductive sintered oxide film in a composite (D4) obtained in Comparative Example 4. [Figure 19] 1 shows an X-ray diffraction pattern of a stabilizing film (Al 2 CoO 4 film) formed on the surface of a silicon nitride substrate in a laminate obtained before producing a composite (C7) in Example 7. [Figure 20] 10 is an X-ray diffraction pattern of a stabilizing film (Al 2 MgO 4 film) formed on the surface of a silicon nitride substrate in a laminate obtained before producing a composite (C8) in Example 8. [Figure 21] 10 is an X-ray diffraction pattern of a stabilizing film (Al 2 ZnO 4 film) formed on the surface of a silicon nitride substrate in a laminate obtained before producing a composite (C9) in Example 9. [Figure 22] 10 is an X-ray diffraction pattern of a stabilizing film (Fe 2 CoO 4 film) formed on the surface of a silicon nitride substrate in a laminate obtained before producing a composite (C10) in Example 10. [Figure 23] 10 is an X-ray diffraction pattern of a stabilizing film (Fe 2 CuO 4 film) formed on the surface of a silicon nitride substrate in a laminate obtained before producing a composite (C11) in Example 11. [Figure 24] 10 is an X-ray diffraction pattern of a stabilizing film (Fe 2 MgO 4 film) formed on the surface of a silicon nitride substrate in a laminate obtained before producing a composite (C12) in Example 12. [Figure 25] 10 is an X-ray diffraction pattern of a stabilizing film (Fe 2 ZnO 4 film) formed on the surface of a silicon nitride substrate in a laminate obtained before producing a composite (C13) in Example 13. [Figure 26] 10 is an X-ray diffraction pattern of a stabilizing film (Ga 2 CoO 4 film) formed on the surface of a silicon nitride substrate in a laminate obtained before producing a composite (C14) in Example 14. [Figure 27] 10 is an X-ray diffraction pattern of a stabilizing film (Ga 2 CuO 4 film) formed on the surface of a silicon nitride substrate in a laminate obtained before producing a composite (C15) in Example 15. [Figure 28] 10 is an X-ray diffraction pattern of a stabilizing film (Ga 2 MgO 4 film) formed on the surface of a silicon nitride substrate in a laminate obtained before producing a composite (C16) in Example 16. [Figure 29] 10 is an X-ray diffraction pattern of a stabilizing film (Ga 2 ZnO 4 film) formed on the surface of a silicon nitride substrate in a laminate obtained before producing a composite (C17) in Example 17. [Figure 30] 1 shows an X-ray diffraction pattern of a conductive sintered oxide film in a composite (D5) obtained in Comparative Example 5. [Figure 31] 10 is an X-ray diffraction pattern of a stabilizing film (Al 2 CuO 4 film) formed on the surface of a gallium nitride thin film on a sapphire substrate in a laminate obtained before producing a composite (C18) in Example 18. [Figure 32] 10 is an X-ray diffraction pattern of a stabilizing film (Ga 2 ZnO 4 film) formed on the surface of a gallium nitride thin film on a sapphire substrate in a laminate obtained before producing a composite (C19) in Example 19. DETAILED DESCRIPTION OF THE INVENTION

[0019] The composite of the present invention comprises a first material part containing a first inorganic material, a second material part containing a second inorganic material having a different composition from the first inorganic material, and a stabilizing layer containing a compound (A) disposed between the first material part and the second material part.

[0020] 1 to 3 show examples of cross-sectional structures of essential parts of a composite body of the present invention that includes a first material part, a second material part, and a stabilizing layer, but the present invention is not limited to these. Fig. 1 shows a composite 1 of a first embodiment having a structure in which a stabilizing layer 14 and a second material part 12 are bonded in that order onto a first material part 10. The stabilizing layer 14 may be a layer made of only the compound (A), or may be a layer made of the compound (A) and another compound (described later). In the present invention, the stabilizing layer 14 may be a single layer as shown in Fig. 1, or, although not shown, may have a structure in which multiple layers containing different compounds (A) are stacked. Fig. 2 shows a composite 2 of a second embodiment having a structure in which a stabilizing layer 24 and a second material part 22 are bonded in this order onto a first material part 20. The stabilizing layer according to the present invention can be provided with a reinforcing layer that does not contain compound (A) (described later), and the stabilizing layer 24 in Fig. 2 is composed of a stabilizing main agent layer 26 that contains compound (A) and reinforcing layers 28, 28 that sandwich the stabilizing main agent layer 26 on both sides. FIG. 3 shows a composite body 3 of a third embodiment having a structure in which a stabilizing layer 34 and a second material part 32 are bonded between first material parts 30, 30 arranged on one surface side and the other surface side.

[0021] The materials constituting the first material portion, the second material portion, and the stabilizing layer will be described below.

[0022] In the present invention, the first inorganic material and the second inorganic material are materials that contain completely different substances, or that contain a common substance but have different compositions.

[0023] In the present invention, the combination of the first inorganic material and the second inorganic material is not particularly limited, and for example, the first inorganic material and the second inorganic material can be, respectively, a nitride and a non-nitride; silicon or a silicon-containing compound and an oxide; an acidic material that reacts with a base to produce a salt; and a basic material that reacts with an acid to produce a salt.

[0024] Examples of nitrides include silicon nitride, aluminum nitride, gallium nitride, boron nitride, titanium nitride, lithium nitride, zinc nitride, and iron nitride.

[0025] Examples of non-nitrides containing oxides include metal elements (Pt, Au, Ag, W, Mo, Nb, or Ta), conductive oxides containing Ru (RuO2, CaCu3Ru4O 12 , SrRuO3, CaRuO3, Ca2RuO4, etc.), superconducting copper oxides (RE 2-x Ba x CuO4, REBa2Cu3O 6+δ , REBa2Cu4O8, RE2Ba4Cu7O 14, Bi2Sr2CuO6, Bi2Sr2CaCu2O8, Bi2Sr2Ca2Cu3O 10 , HgBa2CuO 4+δ , HgBa2CaCu2O 6+δ ,HgBa2Ca2Cu3O 8+δ RE includes rare earth elements such as Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), layered cobalt oxides (sodium cobaltite, calcium cobaltite), perovskite structure oxides (barium titanate, strontium titanate, barium zirconate, barium hafnate, barium stannate, and the like, or compounds in which some of the constituent elements thereof are substituted with different elements, or compounds in which some of the constituent elements are missing), metal oxides (silicon dioxide, quartz, aluminum oxide, sapphire, ferrite, titanium oxide, tin oxide, zinc oxide, copper oxide, cobalt oxide, iron oxide, gallium oxide, molybdenum oxide, hafnium oxide, rare earth oxides other than those mentioned above, and the like), oxides, carbides, sulfides, silicon, and the like.

[0026] Examples of silicon-containing compounds include silicon dioxide, quartz, silicon carbide, metal silicides (Cu5Si, (V, Cr, Mn)3Si, Fe3Si, Mn3Si, (Mg, Ge, Sn, Pb)2Si, (Ca, Ru, Ce, Rh, Ir, Ni)2Si, (Ti, Zr, Hf, Th, Ce, Pu)Si, CaSi, SrSi, YSi, Mg2Si, NiSi, Na2Si, WSi2, MoSi2, TiSi2, etc.).

[0027] Examples of acidic materials that react with a base to form a salt include silicon oxide, chromium oxide, tin oxide, boron oxide, manganese oxide, and rhenium oxide.

[0028] Examples of basic materials that react with acids to produce salts include oxides containing copper (superconducting copper oxide, copper oxide, La4BaCu5O 14+δExamples of suitable oxides include oxygen-deficient perovskite-structured copper oxides such as SiO2, CaO, CaCO3, calcium cobaltite, and the like; compounds containing calcium (CaF2, CaO, CaCO3, calcium cobaltite, and the like); and compounds containing sodium (Na2O, sodium cobaltite, and the like).

[0029] In the present invention, preferred combinations of the first inorganic material and the second inorganic material are shown below. (A) An embodiment in which the first inorganic material contains a nitride and the second inorganic material contains an oxide (excluding the compound (A)) as a non-nitride. (A) An embodiment in which the first inorganic material contains a silicon compound (excluding silicon nitride) or silicon, and the second inorganic material contains an oxide (excluding compound (A)).

[0030] In the above aspect (A), the first inorganic material is preferably a material containing at least one nitride selected from silicon nitride, aluminum nitride, gallium nitride, boron nitride, titanium nitride, lithium nitride, zinc nitride, and iron nitride, particularly preferably silicon nitride, in an amount of 80% by volume or more relative to the entire first inorganic material, and the second inorganic material is preferably a material containing at least one oxide selected from conductive oxides containing Ru and superconducting copper oxides containing rare earth elements, in an amount of 50% by volume or more relative to the entire second inorganic material. When the second inorganic material contains another oxide, copper oxide is preferred.

[0031] In the above aspect (A), the first inorganic material is preferably a material containing silicon dioxide or silicon in an amount of 50% by volume or more relative to the entire first inorganic material, and the second inorganic material is preferably a material containing at least one oxide selected from conductive oxides containing Pt, Au, Ag, W, Mo, Nb, Ta, and Ru, and superconducting copper oxides containing rare earth elements, in an amount of 50% by volume or more relative to the entire second inorganic material. When the second inorganic material contains another oxide, copper oxide is preferred.

[0032] Next, the compound (A) contained in the stabilizing layer will be described. The compound (A) is represented by the general formula (1): M 1 2M 2O4, which are different elements, and M 1 is at least one trivalent element selected from Al, Fe, and Ga, and M 2 is at least one divalent element selected from Cu, Mg, Zn, Fe, Mn, and Co. The stabilizing layer may contain only one type of compound (A), or two or more types of compounds.

[0033] The compound (A) generally has a spinel structure. 1 or M 2 The bonding strength between the compound (A) and O (oxygen) is strong, and the crystal structure is stable. Therefore, when such a compound (A) is contained in the stabilizing layer, the effects of the present invention are fully exhibited.

[0034] In oxides (A2BO4) having a spinel structure, the elements corresponding to the A site are 1 As shown in the figure, the element corresponding to the B site is at least one selected from Al, Fe, and Ga. 2 As shown above, the metal element is at least one selected from Cu, Mg, Zn, Fe, Mn, and Co. Therefore, if the total number of metal elements is 2 at the A site and 1 at the B site, an oxide consisting of multiple elements can be obtained.

[0035] The compound (A) generally has low electrical conductivity. Therefore, for example, when the first inorganic material and the second inorganic material are electrically conductive, a stabilization layer containing the compound (A) can be interposed between the first material part and the second material part to electrically insulate the first material part and the second material part, thereby suppressing chemical reactions and element diffusion that occur between the different first inorganic material and second inorganic material.

[0036] In the oxides having a spinel structure represented by the general formula (1) above, compounds having lower reactivity with the materials to be joined are preferably compounds in which aluminum (Al) is used at the A site. The aluminum (Al) element is contained in alumina, sapphire, aluminum nitride, and the like, which constitute ceramic substrates used in many ceramic products and electronic devices. In this case, if a compound in which copper (Cu) is applied to the B site is used, the reaction with the first inorganic material and the second inorganic material can be suppressed, and this is more preferable as a component constituting the stabilizing layer.

[0037] In the stabilization layer, the proportion of compound (A) contained (if multiple types are present, the proportion of the total amount) is preferably 80% by volume or more, more preferably 90% by volume or more, of the entire stabilization layer, in order to suppress defects such as element diffusion at the stabilization layer side interface in the first material part and the stabilization layer side interface in the second material part.

[0038] When the stabilization layer contains a component other than compound (A), the other component is preferably a component that does not react with compound (A) or decompose compound (A) at 500°C to 1100°C, and can be, for example, at least one of metals, alloys, oxides, carbides, sulfides, etc. In the present invention, oxides and nitrides are preferred. As oxides, aluminum oxide, copper oxide, magnesium oxide, etc. are preferred, and copper oxide is particularly preferred.

[0039] When the stabilizing layer is composed of the compound (A) and other components, the stabilizing layer may be a layer in which these are uniformly mixed, or may be a layer in which the compound (A) is contained with a gradient distribution from the first material part side to the second material part side. In addition, from the viewpoint of density, the stabilization layer is preferably a dense layer.

[0040] In the present invention, the stabilization layer may further include a reinforcing layer containing an inorganic compound other than compound (A) in addition to the portion containing compound (A). The composite 2 in FIG. 2 is a preferred example of a composite including a reinforcing layer. The composite 2 includes a stabilization main layer 26 containing compound (A) and reinforcing layers 28, 28 sandwiching the stabilization main layer 26 on both sides. The advantages of the present invention are difficult to obtain even if a layer containing only a compound other than compound (A), such as aluminum oxide or copper oxide, is provided between a first material portion containing a first inorganic material and a second material portion containing a second inorganic material. In the present invention, not only the composite 1 of the first embodiment shown in FIG. 1, which has a structure in which a stabilization layer 14 and a second material portion 12 are sequentially bonded onto a first material portion 10, but also the composite 2 of the second embodiment shown in FIG. 2, which includes reinforcing layers 28, 28, exhibit excellent structural stability by suppressing defects such as element diffusion at the stabilization layer-side interface of the first material portion and the stabilization layer-side interface of the second material portion.

[0041] The other inorganic compound constituting the reinforcing layer (hereinafter also referred to as "reinforcing layer inorganic compound") can be at least one of oxide, carbide, sulfide, nitride, etc. In the present invention, oxides and nitrides are preferred because they are less likely to peel and have excellent structural stability as an integrated product. Preferred oxides include copper oxide, bismuth oxide, and antimony oxide. In the two reinforcing layers in Figure 2, the inorganic compound contained in one reinforcing layer and the inorganic compound contained in the other reinforcing layer may be the same or different.

[0042] In the present invention, the thickness of the stabilization layer in the embodiment shown in Figures 1 and 2 is not particularly limited, but the lower limit is usually 10 nm, preferably 100 nm, and more preferably 1 µm. The upper limit is selected appropriately depending on the size of the portion where the first material portion and the second material portion face each other or the types of the first inorganic material and the second inorganic material, but is usually 1 mm. Furthermore, the thicknesses of the two reinforcing layers 28, 28 in Figure 2 may be the same or different.

[0043] 1 and 2 are examples of cross sections of a main part of a composite body, and show that the layers are in contact with each other on a flat surface, but this is not limited to a flat surface, and may be an uneven surface. FIG. 2 shows a structure in which a stabilizing layer 24 consisting of a stabilizing main agent layer 26 containing compound (A) and reinforcing layers 28, 28 sandwiching the stabilizing main agent layer 26 on both sides, and a second material part 22 are bonded in this order on top of the first material part 20; however, the reinforcing layer 28 may also be a composite provided either between the first material part 20 and the stabilizing main agent layer 26 or between the stabilizing main agent layer 26 and the second material part 22 (not shown). The composite 3 in Figure 3 is a composite showing a modified example of Figure 1, and has a structure in which a second material part 32 is provided inside, and this second material part 32 is sandwiched between a stabilizing layer 34 and a first material part 30, in that order.

[0044] 1 can be produced by, for example, (a) forming a film or deposition portion for a stabilizing layer (hereinafter, these are also collectively referred to as "stabilizing film") on the surface of a first material portion, and then forming a second material portion on the surface of the stabilizing film in the resulting laminate, or (b) arranging a raw material for forming the stabilizing layer between the first material portion and the second material portion and integrating them. Below, we will explain the method for producing a composite of the present invention, which corresponds to (a) above, in which a film containing compound (A) (stabilizing film) is formed on the surface of the first material portion to form a laminate, and then forming a second material portion on the surface of the compound (A)-containing film (stabilizing film) in the laminate.

[0045] Examples of methods for forming a stabilizing film containing compound (A) on the surface of the first material part (stabilizing film forming method) include: a method in which a dispersion liquid obtained by dispersing particles containing compound (A) in a liquid medium (dispersion medium) such as an organic solvent is applied to the first material part, followed by drying (desolvation), degreasing (de-dispersant) if necessary, and heat treatment (sintering if necessary); a method in which a dispersion liquid obtained by dispersing manufacturing raw materials (particles, etc.) of compound (A) in a liquid medium is applied to the first material part, followed by drying, a baking reaction, and sintering if necessary; a method in which a film containing compound (A) is formed on the first material part using a vapor phase film deposition method such as sputtering, pulsed laser deposition, chemical vapor deposition, metalorganic vapor phase epitaxy, molecular beam epitaxy, or atomic layer deposition; and a method in which a stabilizing film containing compound (A) is formed on the first material part using a chemical solution film deposition method such as a metalorganic compound decomposition method or a sol-gel method. In this way, a method can be applied in which a stabilizing film is formed on the surface of the first material part using a compound (A) that has been prepared in advance, or a method can be applied in which a stabilizing film containing compound (A) is formed on the surface of the first material part using a manufacturing raw material for compound (A).

[0046] Below, we will explain a method for producing Al2CuO4 using the production raw material when compound (A) is Al2CuO4, but Al2CuO4 is not limited to the production method described below and may be obtained by any other production method.

[0047] When producing Al2CuO4, first, copper oxide (CuO, Cu2O, etc.) and aluminum oxide (Al2O3, etc.) are used so as to have a composition ratio of Al2CuO4, and are mixed using, for example, a mortar made of various materials such as agate or alumina, or a ball mill.

[0048] The resulting raw material mixture is then calcined under the conditions described below, but prior to this, it may be formed into a molded body by pressure molding, extrusion molding, sheet molding, casting molding, injection molding or the like.

[0049] The raw material mixture (molded body) is then heated under atmospheric pressure to cause a sintering reaction. The heating temperature is preferably 800°C or higher, more preferably 900°C to 1000°C, and even more preferably 950°C to 1000°C. If the ratio of copper oxide and aluminum oxide to Al2CuO4 is not based on the amount of each compound used, and one of them is used in excess, a mixture consisting of the excess compound and the remaining Al2CuO4 will be obtained after sintering. This is also acceptable within the range in which chemical reactions and element diffusion occurring between the first material portion and the second material portion can be suppressed.

[0050] When using a dispersion containing particles containing the compound (A), a liquid medium, and a dispersant used in combination as needed, the dispersion can be prepared by mixing and dispersing compound (A)-containing particles, the particle size of which has been adjusted to, for example, 10 μm or less using a ball mill or the like, with terpineol, polyethylene glycol, glycerin, toluene, propylene glycol, or the like to a predetermined solids concentration, followed by stirring and dispersing the mixture to form a paste or slurry.

[0051] The method for forming a stabilizing film on the surface of the first material part using the dispersion to obtain a laminate is not particularly limited, and can be a method in which the dispersion is subjected to various film-forming methods such as screen printing, dip coating, spin coating, inkjet printing, etc. to form a coating film, and then heated for desolvation and degreasing to remove the dispersion medium, etc. After this heating, the stabilizing film can be densified by further heating at a high temperature, if necessary, for sintering. Furthermore, a denser stabilizing film can also be obtained by the vapor phase film formation method.

[0052] In the present invention, a preferred method for forming a film containing Al2CuO4 on the surface of the first material part is to use copper oxide (CuO, Cu2O, etc.) and aluminum oxide (Al2O3, etc.) in a composition ratio of Al2CuO4, mix them with a dispersion medium such as terpineol, polyethylene glycol, glycerin, toluene, or propylene glycol to a predetermined solid concentration, and subject the resulting dispersion (paste or slurry) to various film formation methods such as screen printing, dip coating, spin coating, or inkjet printing to form a coating, and then heat the mixture for desolvation and degreasing to remove the dispersion medium, etc., and after this heating, heat the mixture at a higher temperature to perform firing.

[0053] To produce the composite 1 having the structure of Figure 1 by forming a second material portion on the surface of the stabilizing film in the laminate obtained as described above, the following methods can be applied: a dispersion of particles containing the second inorganic material dispersed in a liquid medium (dispersion medium) such as an organic solvent is applied to the surface of the stabilizing film, followed by drying (desolvation), degreasing (de-dispersion) if necessary, and heat treatment (sintering if necessary); a slurry or paste of the second inorganic material (particles, etc.) dispersed in a liquid medium is applied to the surface of the stabilizing film, followed by drying, a firing reaction, and sintering if necessary; a vapor-phase deposition method such as sputtering, pulsed laser deposition, chemical vapor deposition, metalorganic vapor phase deposition, molecular beam epitaxy, or atomic layer deposition is used to form the second material portion on the surface of the stabilizing film; or a chemical solution deposition method such as a metalorganic compound decomposition method or a sol-gel method is used to form the second material portion on the surface of the stabilizing film.

[0054] Next, a preferred method for producing the composite 2 of FIG. 2, that is, a composite having a stabilizing layer 24 including reinforcing layers 28 sandwiching both sides of a stabilizing base layer 26 containing compound (A), will be described.

[0055] First, a dispersion liquid obtained by dispersing particles containing an inorganic compound for the reinforcing layer in a liquid medium (dispersion medium) such as an organic solvent is applied to the surface of the first material part, and then a film for the reinforcing layer is formed by drying (desolvation), degreasing (dedispersion agent) if necessary, and heat treating (sintering if necessary).Next, a stabilizing main component film is formed on the surface of this film by applying the stabilizing film formation method described in the composite manufacturing method of the present invention above.After that, a film for the reinforcing layer is formed on the surface of this stabilizing main component film in the same manner as above to form a stabilizing film having a laminated structure, and then the second material part is formed on the surface of this stabilizing film.

[0056] In the present invention, a composite comprising a first material part, a second material part, and a stabilizing layer disposed therebetween suppresses problems such as chemical reactions and element diffusion that may occur between the first and second inorganic materials, which are different from each other in the past, and therefore can be widely used as an article with excellent structural stability without degrading the properties of the first and second inorganic materials. For example, it is considered useful as a component of various electronic devices, heat-generating components, etc., which have a bonding interface between materials with different chemical properties or a bonding interface between materials with high reactivity to each other, such as a combination of a nitride with a non-nitride such as an oxide or a metal, a combination of a silicon-containing compound with an oxide, or a combination of an acidic material that reacts with a base to produce a salt with a basic material that reacts with an acid to produce a salt. [Example]

[0057] Next, the present invention will be explained in more detail by way of examples, but these are merely illustrative and do not limit the present invention.

[0058] Example 1 In this example, a paste containing CuO particles and Al2O3 particles (a material for forming a stabilization layer containing Al2CuO4) is printed on a silicon nitride (Si3N4) substrate, which has high thermal conductivity and is expected to be a heat dissipation substrate for next-generation power semiconductors, and then heated and sintered to form an Al2CuO4 film.Then, a conductive oxide with a perovskite crystalline structure, CaCu3Ru4O, which is known to have metallic electrical conductivity, is applied to the surface of this Al2CuO4 film. 12 and CuO, a sintering aid that promotes sintering, were printed and heated to sinter a conductive oxide layer-forming material, to produce a composite (hereinafter referred to as "composite (C1)") in which a stabilizing layer containing the compound represented by general formula (1) according to the present invention was interposed between the substrate and the conductive oxide layer, and the composite was evaluated.

[0059] First, we will explain the stabilization layer-forming material printed on the surface of a silicon nitride substrate. CuO particles and Al2O3 particles were mixed so that the CuO content was 32 volume % to obtain an Al2O3 mixed powder containing 32 volume % CuO. Next, the resulting mixed powder was mixed with a dispersion medium mainly composed of terpineol to obtain an Al2O3 paste containing 32 volume % CuO, which is the stabilization layer-forming material.

[0060] Thereafter, the obtained paste (stabilizing layer forming material) was applied to the surface of the silicon nitride substrate by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0061] The resulting paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated further to 1000°C for 3 hours in air to react and sinter the CuO and Al2O3, resulting in a laminate in which the sintered film was adhered closely to the surface of the silicon nitride substrate.

[0062] X-ray diffraction measurement (ray source: CuKα) of the sintered film of the obtained laminate was carried out using a fully automatic multipurpose X-ray diffractometer "SmartLab" (model name) manufactured by Rigaku Co., Ltd. The X-ray diffraction pattern is shown in FIG. According to this, the diffraction pattern has diffraction peaks of Al2CuO4 in addition to the diffraction peaks of silicon nitride that constitutes the substrate, and it was found that the substrate has a spinel structure.

[0063] Then, a conductive oxide layer-forming material was screen-printed on the surface of the sintered film (Al2CuO4 film) of the laminate. This conductive oxide layer-forming material was CaCu3Ru4O synthesized by a solid-state reaction method. 12 CaCu3Ru4O containing 30% CuO by volume, obtained by mixing CaCu3Ru4O particles with CuO particles so that the CuO content was 30% by volume. 12 The mixed powder was mixed with a dispersion medium mainly composed of terpineol to obtain CaCu3Ru4O containing 30% CuO by volume. 12 It is a paste.

[0064] Next, the obtained CaCu3Ru4O containing 30% Cu by volume 12 The paste (conductive oxide layer forming material) was applied by screen printing to the surface of the Al2CuO4 film formed on the silicon nitride substrate using a rubber squeegee and a stainless steel mesh screen to form a conductive paste film.

[0065] The conductive paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated to 1000°C for 12 hours to sinter it, leaving an AlCuO layer and a CaCuRuO layer containing 30% CuO by volume on the surface of the silicon nitride substrate. 12 A composite (C1) was produced comprising the layers in sequence.

[0066] The resulting composite (C1) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film is shown in FIG. According to this, most of the CaCu3Ru4O 12 It can be seen that the RuO2 was sintered without decomposition. In Figure 5, a peak due to RuO2 is seen, but it is an extremely small amount. 12and CaCu3Ru4O, rather than Al2CuO4. 12 This can also be achieved by forming a film directly on a sinterable aluminum oxide substrate and then heating and sintering it at a high temperature.

[0067] The cross section of the obtained composite (C1) was observed using a scanning electron microscope "JSM-6335FM" (model name) manufactured by JEOL Ltd. The photographed image is shown in FIG. According to this, an Al2CuO4 layer 62 and a CaCu3Ru4O layer containing 30% by volume of CuO are formed on the surface of a silicon nitride substrate 61. 12 A sintered film 63 is then formed. The thickness of the Al2CuO4 layer 62 measured from FIG.

[0068] (Comparative Example 1) The same procedure as in Example 1 was carried out except that the Al2CuO4 layer was not formed, and a CaCu3Ru4O containing 30% by volume of CuO was formed on the surface of the silicon nitride substrate. 12 An attempt was made to form a sintered film, and a composite (hereinafter referred to as "composite (D1)") was obtained.

[0069] The resulting composite (D1) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film is shown in FIG. According to this, CaCu3Ru4O 12 No peaks reflecting CaCu3Ru4O were observed. 12 It can be seen that RuO2 has been produced.

[0070] In complex (D1), CaCu3Ru4O 12 The present inventors speculate that the cause of the decomposition is as follows.

[0071] One possible cause is that the silicon nitride and CaCu3Ru4O 12 At the interface, silicon nitride is formed into CaCu3Ru4O 12This is because the oxygen in CaCu3Ru4O is taken away, oxidized, and changed into silicon dioxide. 12 In other words, when a material has an interface between a nitride such as silicon nitride and an oxide, and is subjected to heat treatment such as high-temperature sintering in the atmosphere, the oxygen that constitutes the oxide is taken by the nitride, and the oxide is unable to maintain its crystal structure and decomposes.

[0072] One of the reasons is that the silicon that makes up the silicon nitride of the substrate and CaCu3Ru4O 12 The Ca and Cu that make up the material undergo a chemical reaction when sintered in air at 1000°C for 12 hours, resulting in CaCuSiO 10 This is because impurities such as CaCu3Ru4O are formed, and Ca and Cu are lost. 12 In other words, since silicon can react with various elements to form compounds, when there is an interface between a silicon-containing material and an oxide, when heat treatment such as high-temperature sintering is performed in the atmosphere, the silicon reacts with the elements that make up the oxide, and the oxide that has lost its constituent elements is unable to maintain its crystal structure and decomposes.

[0073] Furthermore, at the interface between a material containing silicon, which is an acidic material that reacts with bases to produce silicates, and a basic material containing Ca, which reacts with hydrochloric acid to produce calcium chloride, or Cu, which reacts with nitric acid to produce copper nitrate, the combination of these highly reactive materials means that the oxides that have lost their constituent elements due to this reaction are unable to maintain their crystalline structure and decompose.

[0074] On the other hand, an Al2CuO4 layer was placed between the silicon nitride substrate and a conductive oxide, CaCu3Ru4O, containing 30% Cu by volume was used. 12 In Example 1, a sintered film was formed. 12Since the Al2CuO4 stabilizing layer did not decompose, it can be seen that the following phenomena, as seen in Comparative Example 1, were suppressed by the Al2CuO4 stabilizing layer: (1) when there is an interface between a nitride (silicon nitride) and an oxide, when heat treatment such as high-temperature sintering is performed in the atmosphere, the oxygen that constitutes the oxide is taken by the nitride, and the oxide is unable to maintain its crystal structure and decomposes; (2) when there is an interface between a silicon-containing material and an oxide, when heat treatment such as high-temperature sintering is performed in the atmosphere, the silicon and the elements that constitute the oxide react, and the oxide that has lost its constituent elements is unable to maintain its crystal structure and decomposes; and (3) when there is an interface between an acidic material and a basic material, when a combination of highly reactive materials results in the oxide losing its constituent elements due to the reaction, and the oxide is unable to maintain its crystal structure and decomposes.

[0075] Example 2 The same procedure as in Example 1 was carried out except that a silicon dioxide (SiO2) substrate was used instead of the silicon nitride substrate, and an Al2CuO4 layer and a CaCu3Ru4O layer containing 30% by volume of CuO were formed on the surface of the silicon dioxide substrate. 12 A composite (hereinafter referred to as "composite (C2)") having these layers in sequence was produced. The resulting composite (C2) contained 30% by volume of CuO. 12 The X-ray diffraction pattern of the sintered film is shown in FIG. According to this, most of the CaCu3Ru4O 12 It can be seen that the RuO2 was sintered without decomposition. In Figure 8, a peak due to RuO2 is seen, but it is an extremely small amount. 12 and CaCu3Ru4O, rather than Al2CuO4. 12 This can also be achieved by forming a film directly on a sinterable aluminum oxide substrate and then heating and sintering it at a high temperature.

[0076] (Comparative Example 2) The same procedure as in Example 2 was carried out except that the Al2CuO4 layer was not formed, and a CaCu3Ru4O containing 30% by volume of CuO was formed on the surface of the silicon dioxide substrate. 12 An attempt was made to form a sintered film, and a composite (hereinafter referred to as "composite (D2)") was obtained.

[0077] The resulting composite (D2) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film is shown in FIG. According to this, CaCu3Ru4O 12 However, peaks reflecting RuO2 were also observed, so it was possible that some of the peaks were CaCu3Ru4O 12 It is thought that it was decomposed.

[0078] In complex (D2), CaCu3Ru4O 12 The present inventors speculate that the cause of the decomposition is as follows.

[0079] One reason is that the silicon that makes up silicon dioxide and CaCu3Ru4O 12 The Ca and Cu that make up the material undergo a chemical reaction when sintered in air at 1000°C for 12 hours, resulting in CaCuSiO 10 This is because impurities such as CaCu3Ru4O are formed, and Ca and Cu are lost. 12 In other words, since silicon can react with various elements to form compounds, when there is an interface between a silicon-containing material and an oxide, when heat treatment such as high-temperature sintering is performed in the atmosphere, the silicon reacts with the elements that make up the oxide, and the oxide that has lost its constituent elements is unable to maintain its crystal structure and decomposes.

[0080] One reason is that the interface between a silicon-containing material such as silicon dioxide, which is an acidic material that reacts with bases to produce silicates, and a basic material that contains Ca, which reacts with hydrochloric acid to produce calcium chloride, or Cu, which reacts with nitric acid to produce copper nitrate, is a highly reactive combination of materials, so the oxide that has lost its constituent elements due to this reaction is unable to maintain its crystalline structure and decomposes.

[0081] On the other hand, an Al2CuO4 layer was placed between a silicon dioxide substrate and a conductive oxide, CaCu3Ru4O, containing 30% CuO by volume. 12 In Example 2, a sintered film was formed.12 Since no decomposition occurred, it can be seen that the following phenomena, as in Comparative Example 2: (1) when there is an interface between a silicon-containing material and an oxide, when heat treatment such as high-temperature sintering is carried out in the atmosphere, the elements that make up the silicon react with the oxide, and the oxide that has lost its constituent elements is unable to maintain its crystal structure and decomposes; and (2) when there is an interface between an acidic material and a basic material, the oxide that has lost its constituent elements is unable to maintain its crystal structure and decomposes due to the reaction caused by a combination of highly reactive materials.

[0082] Example 3 In this example, the same operations as in Example 1 were carried out, except that an AlCuO layer was formed on the surface of a silicon nitride substrate by pulsed laser deposition, and an AlCuO layer and a conductive oxide material, CaCuRuO containing 30% by volume of CuO, were formed on the surface of the silicon nitride substrate. 12 A sintered film was formed to obtain a composite (hereinafter referred to as "composite (C3)").

[0083] The target material used in the pulsed laser deposition method was an AlCuO sintered body obtained by mixing CuO particles and AlO particles so that the molar ratio of Al and Cu elements was Al:Cu = 2:1, pressurizing the resulting mixed powder, and then heating it in air at 1000°C for 12 hours to react and sinter the CuO and AlO to form an AlCuO sintered body.

[0084] An AlCuO film was formed on the surface of a silicon nitride substrate placed in a closed vapor deposition system using the following method. Specifically, a 266 nm wavelength Nd:YAG laser was used to irradiate an AlCuO sintered compact target in a vacuum at room temperature, vaporizing AlCuO to obtain a laminate with an AlCuO film on the surface of the silicon nitride substrate. This laminate was then heated in air at 1000°C for 1 hour to obtain a laminate with an AlCuO sintered film. Then, CaCu3Ru4O containing 30% CuO by volume 12The paste (conductive oxide layer-forming material) was used to carry out the same operation as in Example 1, to obtain a composite (C3).

[0085] The resulting composite (C3) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film is shown in FIG. According to this, most of the CaCu3Ru4O 12 It can be seen that the RuO2 was sintered without decomposition. In Fig. 10, as in Fig. 5 of Example 1, a peak due to RuO2 is observed, but it is an extremely small amount. Therefore, it is considered that the Al2CuO4 film formed on the silicon nitride substrate by pulsed laser deposition was coated with CaCu3Ru4O containing 30% CuO by volume. 12 Even in the method of forming a sintered film, (1) when there is an interface between a nitride such as silicon nitride and an oxide, when heat treatment such as high-temperature sintering is performed in air, the oxygen that makes up the oxide is taken by the nitride, and the oxide is unable to maintain its crystal structure and decomposes; (2) when there is an interface between a material containing silicon and an oxide, when heat treatment such as high-temperature sintering is performed in air, the silicon and the elements that make up the oxide react, and the oxide that has lost its constituent elements is unable to maintain its crystal structure and decomposes; and (3) when there is an interface between an acidic material and a basic material, because the combination of highly reactive materials means that the oxide that has lost its constituent elements due to the reaction is unable to maintain its crystal structure and decomposes. These phenomena were found to be suppressed by the Al2CuO4 that makes up the stabilizing layer.

[0086] Furthermore, the cross section of the obtained composite (C3) was observed, and the image shown in FIG. 11 was obtained. According to this, an Al2CuO4 layer 82 and a CaCu3Ru4O layer containing 30% by volume of CuO are formed on the surface of a silicon nitride substrate 81. 12 A sintered film 83 is then formed. The thickness of the Al2CuO4 layer 82 measured from FIG.

[0087] Example 4 In this example, the stabilization layer forming material (paste containing CuO particles and Al2O3 particles) used in Example 1 is printed on a silicon dioxide (SiO2) substrate, and then heated and sintered to form an Al2CuO4 film. Then, SmBa2Cu3O, which has an oxygen-deficient layered perovskite crystal structure and is known as a copper oxide superconducting material, is applied to the surface of this Al2CuO4 film. y A paste (copper oxide superconducting layer forming material) containing particles consisting of the above was printed and heated and sintered to produce a composite (hereinafter referred to as "composite (C4)") in which a stabilizing layer containing the compound represented by general formula (1) according to the present invention was interposed between a substrate and a copper oxide superconducting layer, and the composite was evaluated.

[0088] First, the stabilizing layer-forming material (paste containing CuO particles and Al2O3 particles) was screen-printed onto the surface of a silicon dioxide substrate to form a paste film in the same manner as in Example 1. Then, heating and firing were carried out to obtain a laminate in which the sintered film was adhered closely to the surface of the silicon dioxide substrate.

[0089] Then, a copper oxide superconducting layer forming material was screen-printed on the surface of the sintered film (Al2CuO4 film) of the laminate. This copper oxide superconducting layer forming material was SmBa2Cu3O synthesized by a solid-state reaction method. y The particles were mixed with a dispersion medium whose main component was terpineol to obtain SmBa2Cu3O. y It is a paste.

[0090] The resulting SmBa2Cu3O y The paste (copper oxide superconducting layer forming material) was applied by screen printing to the surface of the Al2CuO4 film formed on the silicon dioxide substrate using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0091] The paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated further to 950°C in air for 12 hours to sinter it, forming an Al2CuO4 layer and a SmBa2Cu3O4 layer on the surface of the silicon dioxide substrate. yA composite (C4) was produced comprising the layers in sequence.

[0092] The resulting composite (C4) is SmBa2Cu3O y The X-ray diffraction pattern of the sintered film is shown in FIG. According to this, some SmBa2Cu3O y Although there are peaks that suggest that Sm2CuO4 is formed by the decomposition of SmBa2Cu3O, most of the y It can be seen that the Sm2CuO4 content is sintered without decomposition. y This is an extremely small amount compared to the remaining amount.

[0093] (Comparative Example 3) The same procedure as in Example 4 was carried out except that the Al2CuO4 layer was not formed, and a SmBa2Cu3O y An attempt was made to form a sintered film, and a composite (hereinafter referred to as "composite (D3)") was obtained.

[0094] The resulting composite (D3) is SmBa2Cu3O y The X-ray diffraction pattern of the sintered film is shown in FIG. According to this, Sm3Ba3Cu6O 14.1 and Sm2CuO4 were detected, indicating that the copper oxide superconducting material is SmBa2Cu3O y decomposes to give the decomposition product Sm3Ba3Cu6O 14.1 and Sm2CuO4 were produced.

[0095] In the complex (D3), SmBa2Cu3O y The present inventors speculate that the cause of the decomposition is as follows.

[0096] One reason is that the silicon that makes up the silicon dioxide of the substrate and the SmBa2Cu3O y Ba and Cu that make up the alloy undergo a chemical reaction during sintering in air at 950°C for 12 hours, resulting in the formation of Cu. 3.17This is to form Si, Ba2SiO4, etc., and at this time, Ba and Cu are taken away to form SmBa2Cu3O y In other words, since silicon can react with various elements to form compounds, when there is an interface between a silicon-containing material and an oxide, when heat treatment such as high-temperature sintering is performed in the atmosphere, the silicon reacts with the elements that make up the oxide, and the oxide that has lost its constituent elements is unable to maintain its crystal structure and decomposes.

[0097] One reason is that the interface between a silicon-containing material such as silicon dioxide, which is an acidic material that reacts with bases to produce silicates, and a basic material that contains Ba, which reacts with acids to produce barium salts, or Cu, which reacts with nitric acid to produce copper nitrate, is a highly reactive combination of materials, and as a result, the oxide loses its constituent elements due to this reaction, making it unable to maintain its crystalline structure and causing it to decompose.

[0098] On the other hand, an Al2CuO4 layer is interposed between a silicon dioxide substrate and a copper oxide superconducting material, SmBa2Cu3O y In Example 4, a sintered film was formed using SmBa2Cu3O y Since no decomposition occurred, it can be seen that the following phenomenon, as in Comparative Example 3: (1) when there is an interface between a silicon-containing material and an oxide, when heat treatment such as high-temperature sintering is performed in the atmosphere, the elements that make up the silicon react with the oxide, and the oxide that has lost its constituent elements is unable to maintain its crystal structure and decomposes; and (2) when there is an interface between an acidic material and a basic material, the oxide that has lost its constituent elements is unable to maintain its crystal structure and decomposes due to the reaction caused by a combination of highly reactive materials.

[0099] Example 5 In this example, a stabilization layer forming material (a paste containing CuO particles and Al2O3 particles) different from that used in Example 1 etc. is printed on a silicon nitride substrate, and then heated and sintered to form an Al2O3-containing Al2CuO4 film. After that, the CaCu3Ru4O 12A conductive oxide layer-forming material containing CuO was printed and heated and sintered to produce a composite (hereinafter referred to as "composite (C5)") in which a stabilizing layer containing the compound represented by general formula (1) according to the present invention and aluminum oxide (Al2O3) was interposed between the substrate and the conductive oxide layer, and the composite was evaluated.

[0100] First, we will explain the stabilization layer-forming material printed on the surface of a silicon nitride substrate. CuO particles and Al2O3 particles were mixed so that the CuO content was 20% by volume, resulting in an Al2O3 mixed powder containing 20% ​​by volume of CuO. Next, the resulting mixed powder was mixed with a dispersion medium mainly composed of terpineol to obtain an Al2O3 paste containing 20% ​​by volume of CuO, which is the stabilization layer-forming material.

[0101] Thereafter, the obtained Al2O3 paste containing 20% ​​by volume of CuO (stabilizing layer forming material) was applied to the surface of the silicon nitride substrate by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0102] The resulting paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated further to 1000°C for 3 hours in air to react and sinter the CuO and Al2O3, resulting in a laminate in which the sintered film was adhered closely to the surface of the silicon nitride substrate.

[0103] The X-ray diffraction pattern of the sintered film of the obtained laminate is shown in FIG. According to this, it was found that the diffraction pattern contained, in addition to the diffraction peaks of the silicon nitride that constituted the substrate, diffraction peaks of Al2CuO4 produced by the reaction of CuO and Al2O3, and diffraction peaks of Al2O3 that remained uninvolved in the reaction. In other words, it was found that the sintered film contained Al2CuO4 formed by the reaction of CuO particles and Al2O3 particles during sintering, and Al2O3. As mentioned above, this sintered film is called an "Al2O3-containing Al2CuO4 film."

[0104] Thereafter, the conductive oxide layer-forming material used in Example 1 was screen-printed onto the surface of the sintered film (Al2O3-containing Al2CuO4 film) of the laminate. That is, the conductive oxide layer forming material was applied to the surface of the Al2O3-containing Al2CuO4 film by screen printing using a rubber squeegee and a stainless steel mesh screen to form a conductive paste film.

[0105] Next, the obtained conductive paste film was heated in air at 200°C for 30 minutes to remove the dispersion medium. Then, the temperature was further increased to 1000°C in air for 12 hours for sintering, resulting in an Al2O3-containing Al2CuO4 layer and a 30% by volume CuO-containing CaCu3Ru4O layer on the surface of the silicon nitride substrate. 12 A composite (C5) was produced comprising, in order, the layers:

[0106] The resulting composite (C5) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film is shown in FIG. According to this, most of the CaCu3Ru4O 12 It can be seen that the sintered material is sintered without decomposition. Furthermore, in Figure 15, a peak attributable to RuO2 is observed, but only in a very small amount. Therefore, even when the stabilization layer contains other materials in addition to Al2CuO4, the compound represented by general formula (1) according to the present invention, the following phenomena are suppressed by the Al2CuO4 constituting the stabilization layer: (1) When an interface between a nitride (silicon nitride) and an oxide is present, oxygen constituting the oxide is taken by the nitride, causing the oxide to lose its crystal structure and decompose during heat treatment such as high-temperature sintering in air; (2) When an interface between a silicon-containing material and an oxide is present, silicon reacts with elements constituting the oxide, causing the oxide to lose its element and decompose during heat treatment such as high-temperature sintering in air; and (3) When an interface between an acidic material and a basic material is present, the oxide loses its element due to the reaction between the highly reactive materials, causing the oxide to lose its element and decompose.

[0107] Example 6 In this example, a reinforcing layer containing CuO, a stabilizing layer containing Al2CuO4, which is a compound represented by general formula (1) according to the present invention, a reinforcing layer containing CuO, and a stabilizing layer containing CaCu3Ru4O 12 A composite (hereinafter referred to as "composite (C6)") having a conductive oxide layer containing the above in sequence was produced and evaluated.

[0108] To form the two reinforcing layers, CuO paste obtained by mixing CuO particles with a dispersion medium containing terpineol as the main component was used.

[0109] First, the CuO paste was applied to the surface of the silicon nitride substrate by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film for a reinforcing layer.

[0110] The resulting reinforcing layer paste film was then heat-treated in air at 200°C for 30 minutes to remove the dispersion medium, and the temperature was further increased to 1020°C for 3 hours for sintering, forming a first reinforcing film made of CuO on the surface of the silicon nitride substrate.

[0111] Thereafter, the stabilizing layer forming material used in Example 1, an Al2O3 paste containing 32% by volume of CuO, was applied to the surface of the first reinforcing film made of CuO by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0112] The resulting paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated further to 1000°C for 12 hours in air to react and sinter the CuO and AlO, resulting in a laminate in which the AlCuO sintered film was adhered to the surface of the first reinforcing film.

[0113] Thereafter, a CuO paste for forming a reinforcing layer was applied to the surface of the sintered film (Al2CuO4 film) of the laminate by screen printing in the same manner as described above, and a second reinforcing film made of CuO was formed by heating and sintering.

[0114] Next, CaCu3Ru4O containing 30% CuO by volume 12 Using the paste (conductive oxide layer-forming material), the same operation as in Example 1 was carried out to obtain a composite (C6) (see FIG. 16). That is, FIG. 16 is a cross-sectional image of the composite (C6) taken by SEM, and the composite (C6) has, on the surface of a silicon nitride substrate 131, a reinforcing layer 132 containing CuO derived from the first reinforcing film, a stabilizing layer 133 containing AlCuO, a reinforcing layer 134 containing CuO derived from the second reinforcing film, and a stabilizing layer 135 containing CaCuRuO. 12 13 and a conductive oxide layer 135 containing the same.

[0115] The resulting composite (C6) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film is shown in FIG. According to this, the X-ray diffraction pattern is very similar to the X-ray diffraction pattern of the composite (C1) obtained in Example 1, and it is clear that the CuO-containing reinforcing layer is CaCu3Ru4O 12 Even in structures adjacent to a conductive oxide layer containing CaCu3Ru4O 12It can be seen that the silicon nitride substrate and the conductive oxide layer are sintered without decomposition. Also, in Figure 17, peaks attributable to RuO2 are observed, but only in very small amounts. Therefore, even in composite (C6) that includes not only a stabilization layer containing Al2CuO4 but also reinforcing layers between the silicon nitride substrate and the stabilization layer containing Al2CuO4 and between the stabilization layer and the conductive oxide layer, it is possible to prevent the following phenomena: (1) When a nitride (silicon nitride) and an oxide have an interface, oxygen constituting the oxide is taken by the nitride during heat treatment such as high-temperature sintering in air, causing the oxide to lose its crystal structure and decompose; (2) When a silicon-containing material and an oxide have an interface, silicon reacts with elements constituting the oxide, causing the oxide to lose its crystal structure and decompose during heat treatment such as high-temperature sintering in air; and (3) When an acidic material and a basic material have an interface, the oxide loses its element due to the reaction between the highly reactive materials, causing the oxide to lose its crystal structure and decompose.

[0116] Furthermore, to confirm the effect of the reinforcing layer of composite (C6), a test was conducted in which adhesive tape was attached to and peeled off the surface of the conductive oxide layer. No interfacial peeling was observed, and composite (C6) was found to be a strong, integrated product.

[0117] Comparative Example 4 In this example, a CuO layer and a CaCu3Ru4O 12 A composite (hereinafter referred to as "composite (D4)") was prepared by successively forming a conductive oxide layer containing the above. The CuO layer was formed using the same CuO paste as in Example 6. The conductive oxide layer was formed using the same CaCu3Ru4O containing 30% CuO by volume as in Example 1. 12 A paste (conductive oxide layer forming material) was used.

[0118] First, the CuO paste was applied to the surface of a silicon nitride substrate, and then the same operation as in Example 6 was carried out to form a CuO film. Next, the above CaCu3Ru4O containing 30% Cu by volume 12 The paste was applied to the surface of the CuO film, and then the same operation as in Example 1 was carried out to form a conductive oxide sintered film, thereby obtaining a composite (D4).

[0119] The X-ray diffraction pattern of the conductive oxide sintered film in the obtained composite (D4) is shown in FIG. According to this, CaCu3Ru4O contained in the conductive oxide layer forming material 12 No diffraction peaks reflecting RuO2 are observed, and only diffraction peaks reflecting RuO2 are observed. 12 Therefore, in the case of CuO only, the silicon nitride substrate and the conductive oxide material CaCu3Ru4O 12 It can be seen that the effect of the stabilizing layer for suppressing the chemical reaction occurring between the

[0120] Example 7 In this example, a paste containing Co3O4 particles and Al2O3 particles (a material for forming a stabilization layer containing Al2CoO4) is printed on a silicon nitride substrate, and then heated and sintered to form an Al2CoO4 film. After that, a CaCu3Ru4O containing 30% by volume of CuO is applied to the surface of this Al2CoO4 film. 12 was printed on a substrate and sintered by heating to prepare a composite (hereinafter referred to as "composite (C7)") in which a stabilizing layer containing the compound represented by general formula (1) according to the present invention was interposed between the substrate and the conductive oxide layer, and the composite was evaluated.

[0121] First, we will explain the stabilization layer-forming material printed on the surface of a silicon nitride substrate. Co3O4 particles and Al2O3 particles were mixed so that the Co3O4 content was 44 mass% to obtain an Al2O3 mixed powder containing 44 mass% Co3O4. Next, the resulting mixed powder was mixed with a dispersion medium mainly composed of terpineol to obtain an Al2O3 paste containing 44 mass% Co3O4, which is the stabilization layer-forming material.

[0122] Thereafter, the obtained paste (stabilizing layer forming material) was applied to the surface of the silicon nitride substrate by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0123] The resulting paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated further to 1000°C for 2 hours in air to react and sinter the CoO and AlO, resulting in a laminate in which the sintered film was adhered closely to the surface of the silicon nitride substrate.

[0124] The X-ray diffraction pattern of the sintered film of the obtained laminate is shown in FIG. According to this, the diffraction pattern has diffraction peaks of Al2CoO4 in addition to the diffraction peaks of silicon nitride that constitutes the substrate, and it was found that the substrate has a spinel structure.

[0125] Then, CaCu3Ru4O containing 30% CuO by volume 12 The paste (conductive oxide layer forming material) was applied by screen printing to the surface of the Al2CoO4 film formed on the silicon nitride substrate using a rubber squeegee and a stainless steel mesh screen to form a conductive paste film.

[0126] The conductive paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated to 1000°C for 2 hours to sinter it, leaving an Al2CoO4 layer and a CaCu3Ru4O3 layer containing 30% Cu by volume on the surface of the silicon nitride substrate. 12 A composite (C7) was prepared comprising the layers in sequence.

[0127] The resulting composite (C7) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film (not shown) shows that the majority of the 12 It was found that the powder was sintered without decomposition. In addition, a peak due to RuO2 was observed, but it was only a trace amount. This RuO2 is CaCu3Ru4O 12and CaCu3Ru4O, rather than Al2CoO4. 12 This can also be achieved by forming a film directly on a sinterable aluminum oxide substrate and then heating and sintering it at a high temperature.

[0128] Example 8 In this example, a paste containing MgO particles and Al2O3 particles (a material for forming a stabilization layer containing Al2MgO4) is printed on a silicon nitride substrate, and then heated and sintered to form an Al2MgO4 film. After that, a CaCu3Ru4O containing 30% by volume of CuO is applied to the surface of this Al2MgO4 film. 12 was printed on a substrate and sintered by heating to prepare a composite (hereinafter referred to as "composite (C8)") in which a stabilizing layer containing the compound represented by general formula (1) according to the present invention was interposed between the substrate and the conductive oxide layer, and the composite was evaluated.

[0129] First, we will explain the stabilization layer-forming material printed on the surface of a silicon nitride substrate. MgO particles and Al2O3 particles were mixed so that the MgO content was 28 mass% to obtain an Al2O3 mixed powder containing 28 mass% MgO. Next, the resulting mixed powder was mixed with a dispersion medium containing terpineol as the main component to obtain an Al2O3 paste containing 28 mass% MgO, which is the stabilization layer-forming material.

[0130] Thereafter, the obtained paste (stabilizing layer forming material) was applied to the surface of the silicon nitride substrate by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0131] The resulting paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated further to 1100°C for 2 hours in air to react and sinter the MgO and Al2O3, resulting in a laminate in which the sintered film was adhered closely to the surface of the silicon nitride substrate.

[0132] The X-ray diffraction pattern of the sintered film of the obtained laminate is shown in FIG. According to this, the diffraction pattern has diffraction peaks of Al2MgO4 in addition to the diffraction peaks of silicon nitride that constitutes the substrate, and it was found that the substrate has a spinel structure.

[0133] Then, CaCu3Ru4O containing 30% CuO by volume 12 The paste (conductive oxide layer forming material) was applied by screen printing to the surface of the Al2MgO4 film formed on the silicon nitride substrate using a rubber squeegee and a stainless steel mesh screen to form a conductive paste film.

[0134] The conductive paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated to 1000°C for 2 hours to sinter it, forming an Al2MgO4 layer and a CaCu3Ru4O3 layer containing 30% Cu by volume on the surface of the silicon nitride substrate. 12 A composite (C8) was prepared comprising the layers in sequence.

[0135] The resulting composite (C8) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film (not shown) shows that the majority of the 12 It was found that the powder was sintered without decomposition. In addition, a peak due to RuO2 was observed, but it was only a trace amount. This RuO2 is CaCu3Ru4O 12 and CaCu3Ru4O, rather than Al2MgO4. 12 This can also be achieved by forming a film directly on a sinterable aluminum oxide substrate and then heating and sintering it at a high temperature.

[0136] Example 9 In this example, a paste containing ZnO particles and Al2O3 particles (a material for forming a stabilization layer containing Al2MgO4) is printed on a silicon nitride substrate, and then heated and sintered to form an Al2ZnO4 film. After that, a CaCu3Ru4O film containing 30% by volume of CuO is applied to the surface of this Al2ZnO4 film. 12was printed on a substrate and sintered by heating to prepare a composite (hereinafter referred to as "composite (C9)") in which a stabilizing layer containing the compound represented by general formula (1) according to the present invention was interposed between the substrate and the conductive oxide layer, and the composite was evaluated.

[0137] First, we will explain the stabilization layer-forming material printed on the surface of a silicon nitride substrate. ZnO particles and Al2O3 particles were mixed so that the ZnO content was 44 mass% to obtain an Al2O3 mixed powder containing 44 mass% ZnO. Next, the resulting mixed powder was mixed with a dispersion medium containing terpineol as the main component to obtain an Al2O3 paste containing 44 mass% ZnO, which is the stabilization layer-forming material.

[0138] Thereafter, the obtained paste (stabilizing layer forming material) was applied to the surface of the silicon nitride substrate by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0139] The resulting paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated further to 1000°C for 2 hours in air to react and sinter the ZnO and Al2O3, resulting in a laminate in which the sintered film was adhered closely to the surface of the silicon nitride substrate.

[0140] The X-ray diffraction pattern of the sintered film of the obtained laminate is shown in FIG. According to this, the diffraction pattern has diffraction peaks of Al2ZnO4 in addition to the diffraction peaks of silicon nitride that constitutes the substrate, and it was found that the substrate has a spinel structure.

[0141] Then, CaCu3Ru4O containing 30% CuO by volume 12 The paste (conductive oxide layer forming material) was applied by screen printing to the surface of the Al2ZnO4 film formed on the silicon nitride substrate using a rubber squeegee and a stainless steel mesh screen to form a conductive paste film.

[0142] The conductive paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated to 1000°C for 2 hours to sinter it, forming an Al2ZnO4 layer and a CaCu3Ru4O3 layer containing 30% CuO by volume on the surface of the silicon nitride substrate. 12 A composite (C9) was prepared comprising the layers in sequence.

[0143] The resulting composite (C9) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film (not shown) shows that the majority of the 12 It was found that the powder was sintered without decomposition. In addition, a peak due to RuO2 was observed, but it was only a trace amount. This RuO2 is CaCu3Ru4O 12 and CaCu3Ru4O, rather than Al2ZnO4. 12 This can also be achieved by forming a film directly on a sinterable aluminum oxide substrate and then heating and sintering it at a high temperature.

[0144] Example 10 In this example, a paste containing Co3O4 particles and Fe2O3 particles (a material for forming a stabilization layer containing Fe2CO4) is printed on a silicon nitride substrate, and then heated and sintered to form an Fe2CoO4 film. After that, a CaCu3Ru4O containing 30% by volume of CuO is applied to the surface of this Fe2CoO4 film. 12 was printed on a substrate and sintered by heating to prepare a composite (hereinafter referred to as "composite (C10)") in which a stabilizing layer containing the compound represented by general formula (1) according to the present invention was interposed between the substrate and the conductive oxide layer, and the composite was evaluated.

[0145] First, we will explain the stabilization layer-forming material printed on the surface of a silicon nitride substrate. Co3O4 particles and Fe2O3 particles were mixed so that the Co3O4 content was 33 mass% to obtain a 33 mass% Co3O4-containing Fe2O3 mixed powder. Next, the resulting mixed powder was mixed with a dispersion medium mainly composed of terpineol to obtain a 33 mass% Co3O4-containing Fe2O3 paste, which is the stabilization layer-forming material.

[0146] Thereafter, the obtained paste (stabilizing layer forming material) was applied to the surface of the silicon nitride substrate by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0147] The resulting paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated further to 1000°C for 2 hours in air to react and sinter the CoO and FeO, resulting in a laminate in which the sintered film was adhered closely to the surface of the silicon nitride substrate.

[0148] The X-ray diffraction pattern of the sintered film of the obtained laminate is shown in FIG. According to this, the diffraction pattern has a diffraction peak of Fe2CoO4 in addition to the diffraction peak of silicon nitride that constitutes the substrate, and it was found that the substrate has a spinel structure.

[0149] Then, CaCu3Ru4O containing 30% CuO by volume 12 The paste (conductive oxide layer forming material) was applied by screen printing to the surface of the Fe2CoO4 film formed on the silicon nitride substrate using a rubber squeegee and a stainless steel mesh screen to form a conductive paste film.

[0150] The conductive paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated to 950°C for 2 hours to sinter it, forming a Fe2CoO4 layer and a CaCu3Ru4O3 layer containing 30% Cu by volume on the surface of the silicon nitride substrate. 12 A composite (C10) was prepared comprising the layers in sequence.

[0151] The resulting composite (C10) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film (not shown) shows that the majority of the 12It was found that the powder was sintered without decomposition. In addition, a peak due to RuO2 was observed, but it was only a trace amount. This RuO2 is CaCu3Ru4O 12 and CaCu3Ru4O, rather than Fe2CoO4. 12 This can also be achieved by forming a film directly on a sinterable aluminum oxide substrate and then heating and sintering it at a high temperature.

[0152] Example 11 In this example, a paste containing CuO particles and Fe2O3 particles (a material for forming a stabilization layer containing Fe2CuO4) is printed on a silicon nitride substrate, and then heated and sintered to form an Fe2CuO4 film. After that, a CaCu3Ru4O containing 30% by volume of CuO is applied to the surface of this Fe2CuO4 film. 12 was printed on a substrate and sintered by heating to prepare a composite (hereinafter referred to as "composite (C11)") in which a stabilizing layer containing the compound represented by general formula (1) according to the present invention was interposed between the substrate and the conductive oxide layer, and the composite was evaluated.

[0153] First, we will explain the stabilization layer-forming material printed on the surface of a silicon nitride substrate. CuO particles and Fe2O3 particles were mixed so that the CuO content was 33 mass% to obtain a 33 mass% CuO-containing Fe2O3 mixed powder. Next, the resulting mixed powder was mixed with a dispersion medium mainly composed of terpineol to obtain a 33 mass% CuO-containing Fe2O3 paste, which is the stabilization layer-forming material.

[0154] Thereafter, the obtained paste (stabilizing layer forming material) was applied to the surface of the silicon nitride substrate by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0155] The resulting paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated further to 1000°C for 2 hours in air to react and sinter the CuO and Fe2O3, resulting in a laminate in which the sintered film was adhered closely to the surface of the silicon nitride substrate.

[0156] The X-ray diffraction pattern of the sintered film of the obtained laminate is shown in FIG. According to this, the diffraction pattern has a diffraction peak of Fe2CuO4 in addition to the diffraction peak of silicon nitride that constitutes the substrate, and it was found that the substrate has a spinel structure.

[0157] Then, CaCu3Ru4O containing 30% CuO by volume 12 The paste (conductive oxide layer forming material) was applied by screen printing to the surface of the Fe2CuO4 film formed on the silicon nitride substrate using a rubber squeegee and a stainless steel mesh screen to form a conductive paste film.

[0158] The conductive paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated to 950°C for 2 hours to sinter it, forming a FeCuO layer and a CaCuRuO layer containing 30% CuO by volume on the surface of the silicon nitride substrate. 12 A composite (C11) was prepared comprising the layers in sequence.

[0159] The resulting composite (C11) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film (not shown) shows that the majority of the 12 It was found that the powder was sintered without decomposition. In addition, a peak due to RuO2 was observed, but it was only a trace amount. This RuO2 is CaCu3Ru4O 12 and CaCu3Ru4O, rather than Fe2CuO4. 12 This can also be achieved by forming a film directly on a sinterable aluminum oxide substrate and then heating and sintering it at a high temperature.

[0160] Example 12 In this example, a paste containing MgO particles and Fe2O3 particles (a material for forming a stabilization layer containing Fe2MgO4) is printed on a silicon nitride substrate, and then heated and sintered to form an Fe2MgO4 film. After that, a CaCu3Ru4O containing 30% by volume of CuO is applied to the surface of this Fe2MgO4 film. 12was printed on a substrate and sintered by heating to prepare a composite (hereinafter referred to as "composite (C12)") in which a stabilizing layer containing the compound represented by general formula (1) according to the present invention was interposed between the substrate and the conductive oxide layer, and the composite was evaluated.

[0161] First, we will explain the stabilization layer-forming material printed on the surface of a silicon nitride substrate. MgO particles and Fe2O3 particles were mixed so that the MgO content was 20 mass% to obtain a 20 mass% MgO-containing Fe2O3 mixed powder. Next, the resulting mixed powder was mixed with a dispersion medium mainly composed of terpineol to obtain a 20 mass% MgO-containing Fe2O3 paste, which is the stabilization layer-forming material.

[0162] Thereafter, the obtained paste (stabilizing layer forming material) was applied to the surface of the silicon nitride substrate by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0163] The resulting paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated further to 1000°C for 2 hours in air to react and sinter the MgO and Fe2O3, resulting in a laminate in which the sintered film was adhered closely to the surface of the silicon nitride substrate.

[0164] The X-ray diffraction pattern of the sintered film of the obtained laminate is shown in FIG. According to this, the diffraction pattern has a diffraction peak of Fe2MgO4 in addition to the diffraction peak of silicon nitride that constitutes the substrate, and it was found that the substrate has a spinel structure.

[0165] Then, CaCu3Ru4O containing 30% CuO by volume 12 The paste (conductive oxide layer forming material) was applied by screen printing to the surface of the Fe2MgO4 film formed on the silicon nitride substrate using a rubber squeegee and a stainless steel mesh screen to form a conductive paste film.

[0166] The conductive paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated to 1000°C for 2 hours to sinter it, forming a Fe2MgO4 layer and a CaCu3Ru4O3 layer containing 30% Cu by volume on the surface of the silicon nitride substrate. 12 A composite (C12) was prepared comprising the layers in sequence.

[0167] The resulting composite (C12) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film (not shown) shows that the majority of the 12 It was found that the powder was sintered without decomposition. In addition, a peak due to RuO2 was observed, but it was only a trace amount. This RuO2 is CaCu3Ru4O 12 and CaCu3Ru4O, rather than Fe2MgO4. 12 This can also be achieved by forming a film directly on a sinterable aluminum oxide substrate and then heating and sintering it at a high temperature.

[0168] Example 13 In this example, a paste containing ZnO particles and Fe2O3 particles (a material for forming a stabilization layer containing Fe2ZnO4) is printed on a silicon nitride substrate, and then heated and sintered to form an Fe2ZnO4 film. After that, a CaCu3Ru4O film containing 30% by volume of CuO is applied to the surface of this Fe2ZnO4 film. 12 was printed on a substrate and sintered by heating to prepare a composite (hereinafter referred to as "composite (C13)") in which a stabilizing layer containing the compound represented by general formula (1) according to the present invention was interposed between the substrate and the conductive oxide layer, and the composite was evaluated.

[0169] First, we will explain the stabilization layer-forming material printed on the surface of a silicon nitride substrate. ZnO particles and Fe2O3 particles were mixed so that the ZnO content was 34 mass% to obtain a 34 mass% ZnO-containing Fe2O3 mixed powder. The resulting mixed powder was then mixed with a dispersion medium primarily composed of terpineol to obtain a 34 mass% ZnO-containing Fe2O3 paste, which is the stabilization layer-forming material.

[0170] Thereafter, the obtained paste (stabilizing layer forming material) was applied to the surface of the silicon nitride substrate by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0171] The resulting paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and the temperature was then further increased to 1000°C for 2 hours in air to react and sinter the ZnO and Fe2O3, resulting in a laminate in which the sintered film was adhered closely to the surface of the silicon nitride substrate.

[0172] The X-ray diffraction pattern of the sintered film of the obtained laminate is shown in FIG. According to this, the diffraction pattern has a diffraction peak of Fe2ZnO4 in addition to the diffraction peak of silicon nitride that constitutes the substrate, and it was found that the substrate has a spinel structure.

[0173] Then, CaCu3Ru4O containing 30% CuO by volume 12 The paste (conductive oxide layer forming material) was applied by screen printing to the surface of the Fe2ZnO4 film formed on the silicon nitride substrate using a rubber squeegee and a stainless steel mesh screen to form a conductive paste film.

[0174] The conductive paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated to 950°C for 2 hours to sinter it, forming a layer of Fe2ZnO4 and a layer of CaCu3Ru4O containing 30% by volume of CuO on the surface of the silicon nitride substrate. 12 A composite (C13) was prepared comprising the layers in sequence.

[0175] The resulting composite (C13) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film (not shown) shows that the majority of the 12 It was found that the powder was sintered without decomposition. In addition, a peak due to RuO2 was observed, but it was only a trace amount. This RuO2 is CaCu3Ru4O12 and CaCu3Ru4O, rather than Fe2ZnO4. 12 This can also be achieved by forming a film directly on a sinterable aluminum oxide substrate and then heating and sintering it at a high temperature.

[0176] Example 14 In this example, a paste containing Co3O4 particles and Ga2O3 particles (a material for forming a stabilization layer containing Ga2CoO4) is printed on a silicon nitride substrate, and then heated and sintered to form a Ga2CoO4 film. After that, a CaCu3Ru4O containing 30% by volume of CuO is applied to the surface of this Ga2CoO4 film. 12 was printed on a substrate and sintered by heating to prepare a composite (hereinafter referred to as "composite (C14)") in which a stabilizing layer containing the compound represented by general formula (1) according to the present invention was interposed between the substrate and the conductive oxide layer, and the composite was evaluated.

[0177] First, we will explain the stabilization layer-forming material printed on the surface of a silicon nitride substrate. Co3O4 particles and Ga2O3 particles were mixed so that the Co3O4 content was 30 mass% to obtain a Ga2O3 mixed powder containing 30 mass% Co3O4. Next, the resulting mixed powder was mixed with a dispersion medium mainly composed of terpineol to obtain a Ga2O3 paste containing 30 mass% Co3O4, which is the stabilization layer-forming material.

[0178] Thereafter, the obtained paste (stabilizing layer forming material) was applied to the surface of the silicon nitride substrate by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0179] The resulting paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated further to 1000°C for 2 hours in air to react and sinter the CoO and GaO, resulting in a laminate in which the sintered film was adhered closely to the surface of the silicon nitride substrate.

[0180] The X-ray diffraction pattern of the sintered film of the obtained laminate is shown in FIG. According to this, the diffraction pattern has diffraction peaks of Ga2CoO4 in addition to diffraction peaks of silicon nitride that constitutes the substrate, and it was found that the substrate has a spinel structure.

[0181] Then, CaCu3Ru4O containing 30% CuO by volume 12 The paste (conductive oxide layer forming material) was applied by screen printing to the surface of the Ga2CoO4 film formed on the silicon nitride substrate using a rubber squeegee and a stainless steel mesh screen to form a conductive paste film.

[0182] The conductive paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated to 1000°C for 2 hours to sinter it, forming a Ga2CoO4 layer and a CaCu3Ru4O3 layer containing 30% Cu by volume on the surface of the silicon nitride substrate. 12 A composite (C14) was prepared comprising the layers in sequence.

[0183] The resulting composite (C14) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film (not shown) shows that the majority of the 12 It was found that the powder was sintered without decomposition. In addition, a peak due to RuO2 was observed, but it was only a trace amount. This RuO2 is CaCu3Ru4O 12 and CaCu3Ru4O, instead of Ga2CoO4. 12 This can also be achieved by forming a film directly on a sinterable aluminum oxide substrate and then heating and sintering it at a high temperature.

[0184] Example 15 In this example, a paste containing CuO particles and Ga2O3 particles (a material for forming a stabilization layer containing Ga2CuO4) is printed on a silicon nitride substrate, and then heated and sintered to form a Ga2CuO4 film. After that, a CaCu3Ru4O containing 30% by volume of CuO is applied to the surface of this Ga2CuO4 film. 12was printed on a substrate and sintered by heating to prepare a composite (hereinafter referred to as "composite (C15)") in which a stabilizing layer containing the compound represented by general formula (1) according to the present invention was interposed between the substrate and the conductive oxide layer, and the composite was evaluated.

[0185] First, we will explain the stabilization layer-forming material printed on the surface of a silicon nitride substrate. CuO particles and Ga2O3 particles were mixed so that the CuO content was 30 mass% to obtain a Ga2O3 mixed powder containing 30 mass% CuO. Next, the resulting mixed powder was mixed with a dispersion medium containing terpineol as the main component to obtain a Ga2O3 paste containing 30 mass% CuO, which is the stabilization layer-forming material.

[0186] Thereafter, the obtained paste (stabilizing layer forming material) was applied to the surface of the silicon nitride substrate by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0187] The resulting paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated further to 1000°C for 2 hours in air to react and sinter the CuO and GaO, resulting in a laminate in which the sintered film was adhered closely to the surface of the silicon nitride substrate.

[0188] The X-ray diffraction pattern of the sintered film of the obtained laminate is shown in FIG. According to this, the diffraction pattern has diffraction peaks of Ga2CuO4 in addition to diffraction peaks of silicon nitride that constitutes the substrate, and it was found that the substrate has a spinel structure.

[0189] Then, CaCu3Ru4O containing 30% CuO by volume 12 The paste (conductive oxide layer forming material) was applied by screen printing to the surface of the Ga2CuO4 film formed on the silicon nitride substrate using a rubber squeegee and a stainless steel mesh screen to form a conductive paste film.

[0190] The conductive paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated to 950°C for 2 hours to sinter it, forming a Ga2CuO4 layer and a CaCu3Ru4O layer containing 30% CuO by volume on the surface of the silicon nitride substrate. 12 A composite (C15) was prepared comprising the layers in sequence.

[0191] The resulting composite (C15) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film (not shown) shows that the majority of the 12 It was found that the powder was sintered without decomposition. In addition, a peak due to RuO2 was observed, but it was only a trace amount. This RuO2 is CaCu3Ru4O 12 and CaCu3Ru4O instead of Ga2CuO4. 12 This can also be achieved by forming a film directly on a sinterable aluminum oxide substrate and then heating and sintering it at a high temperature.

[0192] Example 16 In this example, a paste containing MgO particles and Ga2O3 particles (a material for forming a stabilization layer containing Ga2MgO4) is printed on a silicon nitride substrate, and then heated and sintered to form a Ga2MgO4 film. After that, a CaCu3Ru4O containing 30% by volume of CuO is applied to the surface of this Ga2MgO4 film. 12 was printed on a substrate and sintered by heating to prepare a composite (hereinafter referred to as "composite (C16)") in which a stabilizing layer containing the compound represented by general formula (1) according to the present invention was interposed between the substrate and the conductive oxide layer, and the composite was evaluated.

[0193] First, we will explain the stabilization layer-forming material printed on the surface of a silicon nitride substrate. MgO particles and Ga2O3 particles were mixed so that the MgO content was 18% by mass, resulting in a Ga2O3 mixed powder containing 18% by mass of MgO. Next, the resulting mixed powder was mixed with a dispersion medium containing terpineol as the main component to obtain a Ga2O3 paste containing 18% by mass of MgO, which is the stabilization layer-forming material.

[0194] Thereafter, the obtained paste (stabilizing layer forming material) was applied to the surface of the silicon nitride substrate by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0195] The resulting paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated further to 1100°C for 2 hours in air to react and sinter the MgO and GaO, resulting in a laminate in which the sintered film was adhered closely to the surface of the silicon nitride substrate.

[0196] The X-ray diffraction pattern of the sintered film of the obtained laminate is shown in FIG. According to this, the diffraction pattern has diffraction peaks of Ga2MgO4 in addition to diffraction peaks of silicon nitride that constitutes the substrate, and it was found that the substrate has a spinel structure.

[0197] Then, CaCu3Ru4O containing 30% CuO by volume 12 The paste (conductive oxide layer forming material) was applied by screen printing to the surface of the Ga2MgO4 film formed on the silicon nitride substrate using a rubber squeegee and a stainless steel mesh screen to form a conductive paste film.

[0198] The conductive paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated to 1000°C for 2 hours to sinter it, forming a Ga2MgO4 layer and a CaCu3Ru4O3 layer containing 30% Cu by volume on the surface of the silicon nitride substrate. 12 A composite (C16) was prepared comprising the layers in sequence.

[0199] The resulting composite (C16) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film (not shown) shows that the majority of the 12 It was found that the powder was sintered without decomposition. In addition, a peak due to RuO2 was observed, but it was only a trace amount. This RuO2 is CaCu3Ru4O12 and CaCu3Ru4O, instead of Ga2MgO4. 12 This can also be achieved by forming a film directly on a sinterable aluminum oxide substrate and then heating and sintering it at a high temperature.

[0200] Example 17 In this example, a paste containing ZnO particles and Ga2O3 particles (a material for forming a stabilization layer containing Ga2ZnO4) is printed on a silicon nitride substrate, and then heated and sintered to form a Ga2ZnO4 film. After that, a CaCu3Ru4O containing 30% by volume of CuO is applied to the surface of this Ga2ZnO4 film. 12 was printed on a substrate and sintered by heating to prepare a composite (hereinafter referred to as "composite (C17)") in which a stabilizing layer containing the compound represented by general formula (1) according to the present invention was interposed between the substrate and the conductive oxide layer, and the composite was evaluated.

[0201] First, we will explain the stabilization layer-forming material printed on the surface of a silicon nitride substrate. ZnO particles and Ga2O3 particles were mixed so that the ZnO content was 18 mass% to obtain a Ga2O3 mixed powder containing 18 mass% ZnO. Next, the resulting mixed powder was mixed with a dispersion medium containing terpineol as the main component to obtain a Ga2O3 paste containing 18 mass% ZnO, which is the stabilization layer-forming material.

[0202] Thereafter, the obtained paste (stabilizing layer forming material) was applied to the surface of the silicon nitride substrate by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0203] The resulting paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and the temperature was then further increased to 1000°C for 2 hours in air to react and sinter the ZnO and Ga2O3, resulting in a laminate in which the sintered film was adhered closely to the surface of the silicon nitride substrate.

[0204] The X-ray diffraction pattern of the sintered film of the obtained laminate is shown in FIG. According to this, the diffraction pattern has diffraction peaks of Ga2ZnO4 in addition to diffraction peaks of silicon nitride that constitutes the substrate, and it was found that the substrate has a spinel structure.

[0205] Then, CaCu3Ru4O containing 30% CuO by volume 12 The paste (conductive oxide layer forming material) was applied by screen printing to the surface of the Ga2ZnO4 film formed on the silicon nitride substrate using a rubber squeegee and a stainless steel mesh screen to form a conductive paste film.

[0206] The conductive paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated to 1000°C for 2 hours to sinter it, forming a Ga2ZnO4 layer and a CaCu3Ru4O3 layer containing 30% Cu by volume on the surface of the silicon nitride substrate. 12 A composite (C17) was prepared comprising the layers in sequence.

[0207] The resulting composite (C17) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film (not shown) shows that the majority of the 12 It was found that the powder was sintered without decomposition. In addition, a peak due to RuO2 was observed, but it was only a trace amount. This RuO2 is CaCu3Ru4O 12 Instead of reacting with Ga2ZnO4, for example, CaCu3Ru4O 12 This can also be achieved by forming a film directly on a sinterable aluminum oxide substrate and then heating and sintering it at a high temperature.

[0208] (Comparative Example 5) The same procedure as in Example 10 was carried out except that the Fe2CoO4 layer was not formed, and a CaCu3Ru4O3 film containing 30% by volume of CuO was formed on the surface of the silicon nitride substrate. 12 An attempt was made to form a sintered film (sintering at 950°C) to obtain a composite (hereinafter referred to as "composite (D5)").

[0209] The resulting composite (D5) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film is shown in FIG. According to this, CaCu3Ru4O 12 It can be seen that a part of the ruthenium dioxide was decomposed and a relatively large amount of RuO2 was produced.

[0210] In complex (D5), CaCu3Ru4O 12 The present inventors speculate that the cause of the partial decomposition is as follows.

[0211] One possible cause is that the silicon nitride and CaCu3Ru4O were sintered at 950°C for 2 hours in air. 12 At the interface, silicon nitride is formed into CaCu3Ru4O 12 This is because the oxygen in CaCu3Ru4O is taken away, oxidized, and changed into silicon dioxide. 12 In other words, when a material has an interface between a nitride such as silicon nitride and an oxide, and is subjected to heat treatment such as high-temperature sintering in the atmosphere, the oxygen that constitutes the oxide is taken by the nitride, and the oxide is unable to maintain its crystal structure and decomposes.

[0212] One of the reasons is that the silicon that makes up the silicon nitride of the substrate and CaCu3Ru4O 12 The Ca and Cu that make up the material undergo a chemical reaction during sintering in air at 950°C for 2 hours, resulting in CaCuSiO 10 This is because impurities such as CaCu3Ru4O are formed, and Ca and Cu are lost. 12 In other words, since silicon can react with various elements to form compounds, when there is an interface between a silicon-containing material and an oxide, when heat treatment such as high-temperature sintering is performed in the atmosphere, the silicon reacts with the elements that make up the oxide, and the oxide that has lost its constituent elements is unable to maintain its crystal structure and decomposes.

[0213] Furthermore, at the interface between a material containing silicon, which is an acidic material that reacts with bases to produce silicates, and a basic material containing Ca, which reacts with hydrochloric acid to produce calcium chloride, or Cu, which reacts with nitric acid to produce copper nitrate, the combination of these highly reactive materials means that the oxides that have lost their constituent elements due to this reaction are unable to maintain their crystalline structure and decompose.

[0214] On the other hand, a Fe2CoO4 layer was placed between the silicon nitride substrate and a conductive oxide, CaCu3Ru4O, containing 30% Cu by volume. 12 In Example 10, a sintered film was formed. 12 Since the Fe2CoO4 stabilization layer did not decompose, it can be seen that the following phenomena, as seen in Comparative Example 5, were suppressed by the Fe2CoO4 stabilization layer: (1) when there is an interface between a nitride (silicon nitride) and an oxide, when heat treatment such as high-temperature sintering is performed in the atmosphere, the oxygen that constitutes the oxide is taken by the nitride, and the oxide is unable to maintain its crystal structure and decomposes; (2) when there is an interface between a silicon-containing material and an oxide, when heat treatment such as high-temperature sintering is performed in the atmosphere, the silicon and the elements that constitute the oxide react, and the oxide that has lost its constituent elements is unable to maintain its crystal structure and decomposes; and (3) when there is an interface between an acidic material and a basic material, when a combination of highly reactive materials is used, the oxide that has lost its constituent elements due to the reaction is unable to maintain its crystal structure and decomposes.

[0215] Example 18 In this example, a paste containing CuO particles and Al2O3 particles (a material for forming a stabilization layer containing Al2CuO4) is printed on the surface of a gallium nitride (GaN) thin film formed on a sapphire substrate, and then heated and sintered to form an Al2CuO4 film. After that, a CaCu3Ru4O containing 30% by volume of CuO is applied to the surface of this Al2CuO4 film. 12 was printed on a substrate and sintered by heating to prepare a composite (hereinafter referred to as "composite (C18)") in which a stabilizing layer containing the compound represented by general formula (1) according to the present invention was interposed between the substrate and the conductive oxide layer, and the composite was evaluated.

[0216] First, we will explain the stabilization layer-forming material printed on the surface of the gallium nitride thin film. CuO particles and Al2O3 particles were mixed so that the CuO content was 32 volume % to obtain an Al2O3 mixed powder containing 32 volume % CuO. Next, the obtained mixed powder was mixed with a dispersion medium mainly composed of terpineol to obtain an Al2O3 paste containing 32 volume % CuO, which is the stabilization layer-forming material.

[0217] Thereafter, the obtained paste (stabilizing layer forming material) was applied to the surface of the gallium nitride thin film by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0218] The resulting paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and then heated further to 1000°C for 2 hours in air to react and sinter the CuO and Al2O3, resulting in a laminate in which the sintered film was adhered closely to the surface of the gallium nitride thin film.

[0219] The X-ray diffraction pattern of the sintered film of the obtained laminate is shown in FIG. According to this, the diffraction pattern has diffraction peaks of Al2CuO4 in addition to the diffraction peaks of gallium nitride that constitutes the substrate, and it was found that the substrate has a spinel structure.

[0220] Then, CaCu3Ru4O containing 30% CuO by volume 12 The paste (conductive oxide layer forming material) was applied by screen printing using a rubber squeegee and a stainless steel mesh screen to the surface of the Al2CuO4 film formed on the gallium nitride thin film, forming a conductive paste film.

[0221] Next, the obtained conductive paste film was heated in air at 200°C for 30 minutes to remove the dispersion medium. Then, the temperature was further increased to 1000°C for 2 hours to sinter it, and an Al2CuO4 layer and a CaCu3Ru4O layer containing 30% by volume of CuO were formed on the surface of the gallium nitride thin film. 12 A composite (C18) was prepared comprising the layers in sequence.

[0222] The resulting composite (C18) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film (not shown) indicates that the 12 Therefore, the Al2CuO4 layer was sintered without decomposition. 12 When forming a sintered film, CaCu3Ru4O is used as a stabilizing layer in the same way as on silicon nitride. 12 It has the effect of suppressing the decomposition of

[0223] Example 19 In this example, a paste containing ZnO particles and Ga2O3 particles (a material for forming a stabilization layer containing Ga2ZnO4) is printed on the surface of a gallium nitride (GaN) thin film formed on a sapphire substrate, and then heated and sintered to form a Ga2ZnO4 film. After that, a CaCu3Ru4O containing 30% by volume of CuO is applied to the surface of this Ga2ZnO4 film. 12 was printed on a substrate and sintered by heating to prepare a composite (hereinafter referred to as "composite (C19)") in which a stabilizing layer containing the compound represented by general formula (1) according to the present invention was interposed between the substrate and the conductive oxide layer, and the composite was evaluated.

[0224] First, we will explain the stabilization layer-forming material printed on the surface of a silicon nitride substrate. ZnO particles and Ga2O3 particles were mixed so that the ZnO content was 18 mass% to obtain a Ga2O3 mixed powder containing 18 mass% ZnO. Next, the resulting mixed powder was mixed with a dispersion medium containing terpineol as the main component to obtain a Ga2O3 paste containing 18 mass% ZnO, which is the stabilization layer-forming material.

[0225] Thereafter, the obtained paste (stabilizing layer forming material) was applied to the surface of the gallium nitride thin film by screen printing using a rubber squeegee and a stainless steel mesh screen to form a paste film.

[0226] The resulting paste film was then heated in air at 200°C for 30 minutes to remove the dispersion medium, and the temperature was then further increased to 1000°C for 2 hours in air to react and sinter the ZnO and Ga2O3, resulting in a laminate in which the sintered film was adhered closely to the surface of the gallium nitride thin film.

[0227] The X-ray diffraction pattern of the sintered film of the obtained laminate is shown in FIG. According to this, the diffraction pattern has diffraction peaks of Ga2ZnO4 in addition to diffraction peaks of gallium nitride that constitutes the substrate, and it was found that the substrate has a spinel structure.

[0228] Then, CaCu3Ru4O containing 30% CuO by volume 12 The paste (conductive oxide layer forming material) was applied by screen printing to the surface of the Ga2ZnO4 film formed on the gallium nitride thin film using a rubber squeegee and a stainless steel mesh screen to form a conductive paste film.

[0229] Next, the obtained conductive paste film was heated in air at 200°C for 30 minutes to remove the dispersion medium. Then, the temperature was further increased to 1000°C for 2 hours to sinter it, and a Ga2ZnO4 layer and a CaCu3Ru4O layer containing 30% by volume of CuO were formed on the surface of the gallium nitride thin film. 12 A composite (C19) was prepared comprising the layers in sequence.

[0230] The resulting composite (C19) contained 30% CuO by volume, CaCu3Ru4O. 12 The X-ray diffraction pattern of the sintered film (not shown) indicates that the 12 Therefore, the Ga2ZnO4 layer was formed on the gallium nitride by sintering without decomposition. 12 When forming a sintered film, CaCu3Ru4O is used as a stabilizing layer in the same way as on silicon nitride. 12 It has the effect of suppressing the decomposition of

[0231] The results obtained in the above examples and comparative examples are shown in Table 1. [Table 1]

[0232] Comparing Comparative Example 1 with Example 1, the first inorganic material, a silicon nitride substrate, and the second inorganic material, CaCu3Ru4O containing 30% Cu by volume, 12 It can be seen that the stabilization layer containing Al2CuO4 as compound (A) disposed between the first inorganic material and the second inorganic material suppresses chemical reactions, element diffusion, etc. that may occur between the first inorganic material and the second inorganic material, resulting in a composite with excellent structural stability without degrading the properties of the first inorganic material and the second inorganic material. In this case, the first inorganic material is a nitride and the second inorganic material is a non-nitride. Furthermore, the first inorganic material is a compound containing silicon, and the second inorganic material is an oxide.

[0233] Comparison of Comparative Example 1 with Examples 7, 8, 9, 12, 14, 16, and 17 reveals that the silicon nitride substrate, which is the first inorganic material, and CaCuRuO containing 30% by volume of CuO, which is the second inorganic material, are different. 12 The stabilization layer containing compound (A) selected from Al2CoO4, Al2MgO4, Al2ZnO4, Fe2MgO4, Ga2CoO4, Ga2MgO4, and Ga2ZnO4, disposed between the first and second inorganic materials, suppresses chemical reactions and element diffusion that may occur between the first and second inorganic materials, resulting in a composite with excellent structural stability without degrading the properties of the first and second inorganic materials. In this case, the first inorganic material is a nitride and the second inorganic material is a non-nitride. Furthermore, the first inorganic material is a silicon-containing compound and the second inorganic material is an oxide.

[0234] Comparison of Comparative Example 5 with Examples 10, 11, 13, and 15 reveals that the silicon nitride substrate, which is the first inorganic material, and CaCuRuO containing 30% by volume of CuO, which is the second inorganic material, are superior in performance to the conventional inorganic material. 12The stabilization layer containing compound (A) selected from Fe2CoO4, Fe2CuO4, Fe2ZnO4, and Ga2CuO4, disposed between the first and second inorganic materials, suppresses chemical reactions and element diffusion that may occur between the first and second inorganic materials, resulting in a composite with excellent structural stability without degrading the properties of the first and second inorganic materials. In this case, the first inorganic material is a nitride and the second inorganic material is a non-nitride. Furthermore, the first inorganic material is a silicon-containing compound and the second inorganic material is an oxide.

[0235] Comparing Comparative Example 2 with Example 2, the first inorganic material, a silicon dioxide substrate, and the second inorganic material, CaCu3Ru4O containing 30% Cu by volume, 12 It can be seen that the stabilization layer containing Al2CuO4 as compound (A) disposed between the first inorganic material and the second inorganic material suppresses chemical reactions, element diffusion, and other events that may occur between the first inorganic material and the second inorganic material, resulting in a composite with excellent structural stability without degrading the properties of the first and second inorganic materials. In this case, the first inorganic material is a silicon-containing compound, and the second inorganic material is an oxide. Furthermore, the first inorganic material is an acidic material that reacts with bases to produce salts, and the second inorganic material is a basic material that reacts with acids to produce salts.

[0236] Comparing Example 1 and Example 3, the silicon nitride substrate as the first inorganic material and CaCu3Ru4O containing 30% by volume of CuO as the second inorganic material 12 It can be seen that, regardless of the method of forming a stabilizing film containing Al2CuO4 as compound (A) as a stabilizing layer between the first inorganic material and the second inorganic material, and regardless of the thickness of the stabilizing layer, chemical reactions, element diffusion, etc. that may occur between the first inorganic material and the second inorganic material are suppressed, resulting in a composite with excellent structural stability without degrading the properties of the first inorganic material and the second inorganic material.

[0237] A comparison between Comparative Example 3 and Example 4 shows that the first inorganic material, a silicon dioxide substrate, and the second inorganic material, SmBa2Cu3O yIt can be seen that the stabilization layer containing Al2CuO4 as compound (A) disposed between the first inorganic material and the second inorganic material suppresses chemical reactions, element diffusion, and other events that may occur between the first inorganic material and the second inorganic material, resulting in a composite with excellent structural stability without degrading the properties of the first and second inorganic materials. In this case, the first inorganic material is a silicon-containing compound, and the second inorganic material is an oxide. Furthermore, the first inorganic material is an acidic material that reacts with bases to produce salts, and the second inorganic material is a basic material that reacts with acids to produce salts.

[0238] Comparing Example 1 and Example 5, the silicon nitride substrate as the first inorganic material and CaCu3Ru4O containing 30% Cu by volume as the second inorganic material 12 It can be seen that even when the stabilization layer contains Al2O3 in addition to compound (A), Al2CuO4, chemical reactions, element diffusion, etc. that may occur between the first inorganic material and the second inorganic material are suppressed, resulting in a composite with excellent structural stability without deteriorating the properties of the first inorganic material and the second inorganic material.

[0239] Comparing Example 1 and Example 6, the silicon nitride substrate as the first inorganic material and CaCu3Ru4O containing 30% by volume of CuO as the second inorganic material 12 It can be seen that even when copper oxide (CuO) is included as a reinforcing layer between compound (A) Al2CuO4 and the first and second inorganic materials in the stabilization layer between them, chemical reactions, element diffusion, etc. that may occur between the first and second inorganic materials are suppressed, resulting in a composite with excellent structural stability without degrading the properties of the first and second inorganic materials.

[0240] A comparison between Comparative Example 4 and Example 6 shows that the silicon nitride substrate, which is the first inorganic material, and the CaCu3Ru4O containing 30% by volume of CuO, which is the second inorganic material, 12It can be seen that when only copper oxide (CuO), which was included in the stabilization layer in Example 6, was placed between the first and second inorganic materials as a reinforcing layer, chemical reactions, element diffusion, etc. that may occur between the first and second inorganic materials were not suppressed, and a composite with excellent structural stability was not obtained without degrading the properties of the first and second inorganic materials. Therefore, it can be seen that in Example 6, compound (A), Al2CuO4, suppresses chemical reactions, element diffusion, etc. that may occur between the first and second inorganic materials.

[0241] Comparing Example 18 with Example 1, the first inorganic material, a gallium nitride thin film on a sapphire substrate, and the second inorganic material, CaCu3Ru4O containing 30% by volume of CuO, 12 It can be seen that the stabilization layer containing Al2CuO4 as compound (A) disposed between the first inorganic material and the second inorganic material suppresses chemical reactions, element diffusion, etc. that may occur between the first inorganic material and the second inorganic material, resulting in a composite with excellent structural stability without deteriorating the properties of the first inorganic material and the second inorganic material. In this case, the first inorganic material is a nitride and the second inorganic material is a non-nitride.

[0242] Comparing Example 19 with Example 17, the first inorganic material, a gallium nitride thin film on a sapphire substrate, and the second inorganic material, CaCu3Ru4O containing 30% Cu by volume, 12 It can be seen that the stabilization layer containing Ga2ZnO4 as compound (A) disposed between the first inorganic material and the second inorganic material suppresses chemical reactions, element diffusion, etc. that may occur between the first inorganic material and the second inorganic material, resulting in a composite with excellent structural stability without deteriorating the properties of the first inorganic material and the second inorganic material. In this case, the first inorganic material is a nitride and the second inorganic material is a non-nitride. [Industrial Applicability]

[0243] The composite of the present invention includes a stabilizing layer that suppresses chemical reactions, element diffusion, and other reactions that may occur between two inorganic materials of different compositions when they are bonded, and therefore can be widely used as an article with excellent structural stability without deteriorating the properties of the first and second inorganic materials. For example, the composite is useful for components of various electronic devices, heat-generating components, and the like, which have a bonded interface between materials with different chemical properties or a bonded interface between materials with high reactivity to each other, such as a combination of a nitride with a non-nitride such as an oxide or a metal, a combination of a silicon-containing compound with an oxide, or a combination of an acidic material that reacts with a base to produce a salt with a basic material that reacts with an acid to produce a salt. [Explanation of symbols]

[0244] 1,2,3: Complex 10,20,30: 1st Materials Department 12,22,32: 2nd material department 14, 24, 34: Stabilization layers 26: Stabilizing base layer 28: Reinforcement layer

Claims

1. A composite comprising: a first material portion including a first inorganic material; a second material portion including a second inorganic material having a different composition from the first inorganic material; and a stabilizing layer disposed between the first material portion and the second material portion, The stabilizing layer contains a compound (A) represented by the following general formula (1): M １ ２ M ２ O ４ (1) (In the formula, M １ and M ２ are different elements, and M １ is at least one selected from Al, Fe, and Ga, and M ２ is at least one selected from Cu, Zn, Fe, Mn, and Co. A composite characterized in that the first inorganic material and the second inorganic material are a combination of the following (1) or (2): (1) The first inorganic material includes a nitride, and the second inorganic material includes an oxide (excluding the compound (A)). (2) The first inorganic material contains a silicon compound (excluding silicon nitride) or silicon, and the second inorganic material contains an oxide (excluding the compound (A)).

2. The compound (A) is Al ２ CuO ４ The complex according to claim 1,

3. The composite according to claim 1 or 2, wherein the stabilizing layer comprises a reinforcing layer containing an inorganic compound (excluding the compound (A)).

4. The composite according to claim 3 , wherein the inorganic compound contained in the reinforcing layer comprises copper oxide.

5. A method for producing the composite of claim 1 or 2, comprising: a compound (A)-containing film containing the compound (A) formed on a surface of the first material part to form a laminate, and then the second material part formed on a surface of the compound (A)-containing film in the laminate.

6. 6. The composite production method according to claim 5, wherein the laminate is obtained by applying a paste containing a production raw material for the compound (A) and a dispersion medium to the surface of the first material part, heating the formed coating film to remove the dispersion medium, and then further increasing the temperature to produce the compound (A) and form the compound (A)-containing film.

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