JP2012124497A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device that contains a junction material which contains no lead component and has a junction strength/fracture toughness that are higher than conventional technology as a junction layer of an electrical connection part in an electronic component.SOLUTION: The semiconductor device of the present invention has electronic members electrically connected together through a junction layer. The junction layer contains an Ag matrix and a dispersion phase, which is made of a metal X whose hardness is higher than that of Ag, being dispersed in the Ag matrix. The Ag matrix and the metal X dispersion phase are metal-jointed together. The Ag matrix and the top surface of the electronic member are metal-jointed together. The metal X dispersion phase and the top surface of the electronic member are metal-jointed together. The metal X dispersion phase contains a crystal grain of 1 μm or less. The Ag matrix contains a crystal grain smaller than 100 nm.

Description

  The present invention relates to a bonding layer of an electric bonding portion (for example, a bonding portion between a semiconductor element and a circuit member) in an electronic component (particularly a semiconductor device), and in particular, Ag (silver) particles having a particle size of 1 to 1000 nm. The present invention relates to a bonding material mainly composed of a semiconductor material, a semiconductor device having a portion bonded using the bonding material, and a method for manufacturing the same. Hereinafter, semiconductor elements, circuit members, and the like are collectively referred to as electronic members.

  In general, when the particle size of metal particles is reduced to nanometer size and the number of constituent atoms per particle decreases, the influence of the surface area on the volume of the particles increases rapidly, and the melting point and sintering temperature are greatly increased compared to the bulk state. (In this specification, a particle having a particle size of 1 to 1000 nm is defined as a nanoparticle). And the report applied as a joining material in the electronics mounting using the low temperature sintering property of this metal nanoparticle is made (for example, refer nonpatent literature 1).

  In Patent Document 1, using a bonding material mainly composed of metal nanoparticles with an average particle diameter of 100 nm or less coated with an organic material, the organic material is decomposed by heating and the metal nanoparticles are sintered together. It is described to do. In the bonding method, the metal particles after bonding are bonded to each other by a metal bond and changed to a bulk metal as a whole. Therefore, the metal particles are considered to have very high heat resistance, reliability, and high heat dissipation. Patent Document 1 also describes a method of mixing metal particles of about 100 μm or less as an aggregate with the above-described bonding material.

  On the other hand, in connection with electronic parts and the like, in recent years, there has been a demand for lead-free solder, but an alternative material for high-temperature solder (melting point: about 300 ° C.) has not yet been determined. The use of hierarchical solder is indispensable for mounting electronic components and the like, and the emergence of a material that replaces the currently used high-temperature solder (lead content: about 96%) is strongly desired.

Proceedings of the 13th Microelectronics Symposium (MES2003), pp. 96-99. JP 2004-107728 A

  Prior art as described above is expected as an alternative material for high-temperature solder (lead content: about 96%) that is normally used, but when used in a high-temperature environment of 300-400 ° C (manufacturing electronic components) If the high temperature environment is experienced in the process), good results may not be obtained in terms of bonding strength. The present invention has been made in view of such problems.

  Therefore, the object of the present invention is compared with the case where a bonding material using Ag nanoparticles of the prior art is used in the electrical bonding between electronic members in the manufacturing process of electronic components (particularly, the manufacturing process of a semiconductor device). An object of the present invention is to provide a semiconductor device having, as a bonding layer, a bonding material that can provide higher bonding strength and fracture toughness.

In order to achieve the above object, the present invention is a semiconductor device in which electronic members are electrically connected to each other through a bonding layer,
The bonding layer includes an Ag matrix, and a dispersed phase composed of a metal X dispersed in the Ag matrix and having a hardness higher than Ag.
The Ag matrix and the metal X dispersed phase are metal bonded to each other, the Ag matrix and the outermost surface of the electronic member are metal bonded to each other, and the metal X dispersed phase and the outermost surface of the electronic member are bonded to each other. And
The metal X dispersed phase includes crystal grains of 1 μm or less, and the Ag matrix includes crystal grains smaller than 100 nm.

  According to the present invention, in the electrical joining of members in an electronic component manufacturing process (especially a semiconductor device manufacturing process), a bonding material capable of obtaining higher bonding strength and fracture toughness than those of the prior art is bonded. A semiconductor device including the layer can be provided.

In the present invention described above, it is preferable to add the following improvements and changes.
(I) The metal X dispersed phase is composed of a plurality of crystal grains, and the plurality of crystal grains are metal-bonded without intervening an oxide film.
(Ii) The mass ratio of the metal X dispersed phase to the Ag matrix is greater than 0 and less than 1.
(Iii) An interdiffusion layer caused by crystals sandwiching the interface is formed in the bonding interface region of the metal bond.
(Iv) The metal X dispersed phase is substantially a sphere or an ellipsoid, and the diameter is when the metal X dispersed phase can be regarded as a substantially sphere, and the length when the metal X dispersed phase can be regarded as a substantially ellipsoid. The axis is in the range of “T / (2 × 10 ⁴ ) to T / 2” with respect to the thickness T of the bonding layer.
(V) The distance from one dispersed phase to the nearest dispersed phase in the metal X dispersed phase is in the range of “T / (4 × 10 ⁴ ) to T / 2”.
(Vi) The outermost surface of the electronic member is a metallized layer formed on the surface of the electronic member, and the metallized layer is made of any of Au, Pt, Pd, Ag, Cu, Ni, or an alloy thereof. ing.
(Vii) The metal X is Cu and / or Ni.

  The present invention has been completed by the inventors' extensive research and research on bonding materials used in semiconductor devices. First, the preliminary examination in the joining process performed by the present inventors will be described.

The present inventors examined the shear strength of the joint part in which Cu (copper) electrodes were joined together using the following joining material mainly composed of Ag nanoparticles.
(1) Bonding material in which Ag nanoparticles with a particle diameter of 1 to 100 nm coated with organic substances and Cu nanoparticles with an average particle diameter of 0.2 μm not coated with organic substances are mixed (2) Particle diameters coated with organic substances Bonding material in which Ag nanoparticles of 1-100 nm and Cu particles with an average particle size of 5 μm not coated with organic substances are mixed (3) Bonding material only of Ag nanoparticles with particle diameters of 1-100 nm coated with organic substances (Reference sample)
Each bonding material was investigated by changing the mass ratio of Cu particles to Ag nanoparticles and the heat treatment temperature. The joining conditions were a heat treatment temperature of 300 to 400 ° C., a joining time of 150 s, and a joining pressure of 2.5 MPa. For the shear test, a bond tester (manufactured by Seishin Shoji Co., Ltd., SS-100KP, maximum load 100 kg) was used (other details will be described later). The results are shown in FIGS.

  FIG. 1 is a graph showing the relationship between the mass ratio of Cu particles to Ag nanoparticles and the normalized shear strength in the bonding material (1). FIG. 2 is a graph showing the relationship between the mass ratio of Cu particles to Ag nanoparticles and the normalized shear strength in the bonding material of (2). The normalized shear strength is normalized with the shear strength in the case of the above-mentioned bonding material (3) (only Ag nanoparticles, mass ratio of Cu particles = 0) being 1. As can be seen from FIGS. 1 and 2, in any case, it was found that the shear strength of the joint tends to decrease as the mass ratio of the Cu particles in the joining material increases.

  Therefore, in order to investigate the factor of the tendency, the joint structure during and after the fracture by the shear test was observed. FIG. 3 is a model diagram showing a cross section of the Cu electrode joint. As shown in FIG. 3, the Cu electrode 301 and the Cu electrode 302 are joined via a joining material 300. The bonding material 300 is made of Ag nanoparticles and Cu particles (aggregate) as described above, and has a structure in which the aggregate 304 is dispersed in the matrix of the sintered silver 303 by heat treatment.

  As a result of observing the joint microstructure during and after the fracture by the shear test, the main fracture path and / or the origin of fracture are the interface parts 305 and 306 between the aggregates 304 (Cu particles), and the aggregate 304. And the Cu electrodes 301 and 302 at the interfaces 307 and 308. This is because the bonding strength in these regions (305 to 308) is the strength inside the sintered silver 303 formed by Ag nanoparticles, the bonding strength at the interface 309 between the sintered silver 303 and the aggregate 304, and the sintering strength. This strongly suggests that the bonding strength of the interface portions 310 and 311 between the silver joint 303 and the Cu electrodes 301 and 302 is low.

  Further, comparing FIG. 1 and FIG. 2, it can be seen that the bonding material (1) shown in FIG. 1 has a smaller normalized shear strength than the bonding material (2) shown in FIG. This can be thought of as follows. The aggregate (Cu nanoparticles with an average particle size of 0.2 μm) in the bonding material of (1) has a smaller particle size than the aggregate (Cu particles with an average particle size of 5 μm) in the bonding material of (2). It is considered that there are many aggregated portions between aggregates even in the Ag matrix. Aggregation of aggregates tends to be a joint failure portion caused by an interface portion between aggregates as shown by 305 and 306 in FIG. 3, and constitutes a fracture starting point and a fracture path in a shear test. For this reason, it was thought that the normalized shear strength was smaller in the bonding material (1) than in the bonding material (2).

  Embodiments according to the present invention will be described below with reference to the drawings. However, the present invention is not limited to the embodiment taken up here, and may be appropriately combined.

  The present invention is a semiconductor device in which electronic members are electrically connected to each other through a bonding layer, and the bonding layer includes an Ag matrix and a metal X dispersed in the Ag matrix and having a hardness higher than Ag. The Ag matrix and the metal X dispersed phase are metal bonded to each other, the Ag matrix and the outermost surface of the electronic member are metal bonded to each other, and the metal X dispersed phase and the electronic member are The metal X dispersed phase includes crystal grains of 1 μm or less, and the Ag matrix includes crystal grains smaller than 100 nm. Metal X is dispersed almost uniformly in the Ag matrix, and each interface forms a good metal bond, so that the mechanical strength (for example, shear strength) is higher than the sintered structure of Ag phase alone or only metal X phase. ) Is improved.

  In general, the mechanism of stress fracture in a single phase is that a micro crack is first generated by the stress, and then the stress is concentrated around the tip of the generated crack. It is said to lead to destruction. The mechanism called dispersion strengthening or precipitation strengthening is to disperse a phase that is less plastically deformed than the matrix phase (so-called hard phase) in the matrix phase, thereby allowing the dispersed phase to function as a crack growth barrier, By making the dispersed phase function as dislocation pinning, the fracture toughness and strength as a whole are improved.

  In the above shear test results, the joint materials (1) and (2), which should be expected to be dispersion strengthened, tend to have lower shear strength than the joint material of only Ag nanoparticles (Cu particle mass ratio = 0). It was seen. From the microstructure observation, the balance of bonding strength at all interfaces such as the interface between the matrix phase and the dispersed phase, the interface between the matrix phase and the electronic member, the interface between the dispersed phase and the electronic member, and the interface inside the dispersed phase (all It has been found that it is important that the interface has a good bonding strength. That is, the point in the present invention is that all the interfaces existing in the bonding layer are metal-bonded.

  In other words, in the bonding layer, the interface between the sintered silver layer and the metal X dispersed phase, the interface between the sintered silver layer and the outermost surface of the electronic member, the interface between the metal X dispersed phase and the outermost surface of the electronic member, metal X If there is an interface inside the dispersed phase, if any one of the interfaces is in a bonded state, the region is likely to become a starting point of cracks or a crack transmission path when stress is applied, and the shear strength is high. It drops significantly. In the present invention, the bonded state in which metal bonding is not obtained means that there is a gap or the like at the bonding interface and adhesion is not obtained, or bonding is performed through one or both oxide film layers. Is defined as In the present invention, the state of metal bonding refers to the state of sintering without an oxide film layer, and in the case of a dissimilar metal interface, mutual bonding is performed in the bonding interface region (for example, about 15 nm from the interface). It is defined as a state in which a diffusion layer is formed. The presence or absence of an oxide film layer or an interdiffusion layer can be evaluated by, for example, TEM-EDX (transmission electron microscope-energy dispersive X-ray analyzer).

The effects of strengthening the joint and improving the fracture toughness described above are exhibited when the metal X is dispersed in the Ag matrix, that is, the Ag matrix forms a network in the form of a network with respect to the dispersed phase. More specifically, when the metal X dispersed phase is substantially a sphere or an ellipsoid, and the metal X dispersed phase can be regarded as a substantially sphere, the diameter is long, and when the metal X dispersed phase can be regarded as a substantially ellipsoid, the length is long. The axis is preferably in the range of “T / (2 × 10 ⁴ ) to T / 2” with respect to the thickness T of the bonding layer. Furthermore, it is desirable that the distance from one disperse phase to the nearest disperse phase is in the range of “T / (4 × 10 ⁴ ) to T / 2”. If it is out of the above range, the function expected as an aggregate by the metal X dispersed phase is not exhibited.

  Ag is preferred as the matrix phase of the bonding layer. This is because the metal forming the matrix is preferably superior in sintering ability to the metal forming the dispersed phase. Excellent sinterability is a characteristic that means that the surface diffusion coefficient and volume diffusion coefficient constituting the sintering mechanism are large. Further, since surface diffusion has a great influence on the formation of the sintered layer, having a property (precious property) that is difficult to oxidize so as not to inhibit the surface diffusion strongly affects the sintering ability. From this point of view, Cu, Ag, Au (gold), Pt (platinum), or Pd (palladium) can be used alone or as a metal for forming a matrix. It is. Among them, Ag having the largest diffusion coefficient is preferable. From this point of view, it is considered that the strength and fracture toughness of the joint where Ni (nickel) having a higher hardness is dispersed in the Cu matrix are improved as compared with the case where only Cu is used.

  The dispersed structure as described above is more than Ag nanoparticles having a particle size of 1 to 1000 nm in which individual particle surfaces are coated with organic substances, and Ag particles having a particle diameter of 1 to 1000 nm in which individual particle surfaces are coated with organic substances. It can be obtained by mixing and sintering hard metal X nanoparticles (details will be described later). The “hard metal” means, for example, a metal having a Vickers height higher than Ag in an annealed state. If the metal X particles are not dispersed in the Ag matrix, the interface between the metal X particles and the interface between the metal X particles and the outermost surface of the electronic member tend to be brittle, and the object of the present invention cannot be achieved. Here, becoming brittle (fragile interface) means a state in which there is a gap at the interface between the metal X particles, the interface between the metal X particles and the outermost surface of the electronic member, or metal bonding is not obtained. . Moreover, the particle size distribution of the metal nanoparticles (Ag and metal X) is preferably 1 to 1000 nm, and more preferably 1 to 100 nm. On the other hand, it is preferable that the amount of the organic substance covering the surface of each metal nanoparticle is 1 to 15 mass% of the entire bonding material before the heat treatment. More preferably, it is 1-10 mass%. If the amount of the organic substance is suppressed as much as possible within the range in which the surface of each metal nanoparticle can be uniformly coated, the time and labor required for removing the organic substance can be reduced, and the joining process can be shortened and the temperature can be reduced.

  There is no particular limitation on the method of coating metal nanoparticles having a particle size of 1 to 1000 nm with an organic substance, and a known method can be used as long as the surface of each particle can be uniformly coated. Further, the form of the coating is not particularly limited as long as the organic substance covering the metal nanoparticles is an organic substance that prevents aggregation of the metal nanoparticles and can be dispersed independently (substantially uniformly) in the dispersion medium. As a kind of organic substance, 1 or more types of organic substances chosen from carboxylic acids, alcohols, and amines are preferable. Note that “class” includes ions, complexes, and the like derived from cases where organic substances are chemically bonded to metals. However, it is preferable to avoid organic substances containing sulfur or halogen elements because the elements may remain in the bonded layer after bonding and cause corrosion.

  Examples of carboxylic acids include acetic acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, myristolein Acid, palmitoleic acid, oleic acid, elaidic acid, erucic acid, nervonic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, succinic acid, oxalic acid, malonic acid, maleic acid, fumaric acid, succinic acid, glutaric acid, Malic acid, adipic acid, citric acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, 2,4-hexadiynecarboxylic acid, 2,4-heptadiynecarboxylic acid, 2,4-octadiynecarboxylic acid, 2,4-decadiynecarboxylic acid, 2,4-dodecadiynecarboxylic acid, 2,4-tetradecadiinca Boronic acid, 2,4-pentadecadiyne carboxylic acid, 2,4-hexadecadiyne carboxylic acid, 2,4-octadecadiine carboxylic acid, 2,4-nonadecadiyne carboxylic acid, 10,12-tetradecadiyne Carboxylic acid, 10,12-Pentadecadiyne carboxylic acid, 10,12-Hexadecadiine carboxylic acid, 10,12-Heptadecadiine carboxylic acid, 10,12-Octadecadiyne carboxylic acid, 10,12-tricosadiyne Carboxylic acid, 10,12-pentacosadiyne carboxylic acid, 10,12-hexacosadiyne carboxylic acid, 10,12-heptacosadiyne carboxylic acid, 10,12-octacosadiyne carboxylic acid, 10,12-nonacosadi Examples thereof include incarboxylic acid, 2,4-hexadiyne dicarboxylic acid, 3,5-octadiyne dicarboxylic acid, 4,6-decadiyne dicarboxylic acid, and 8,10-octadecadin dicarboxylic acid.

  Examples of alcohols include ethyl alcohol, propyl alcohol, butyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, dodecyl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, Examples include oleyl alcohol, linoleyl alcohol, ethylene glycol, triethylene glycol, and glycerin.

  Examples of amines include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine Amine, hexadecylamine, heptadecylamine, octadecylamine, oleylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, isopropylamine, 1,5 -Dimethylhexylamine, 2-ethylhexylamine, di (2-ethylhexyl) amine, methylenediamine, trimethylamine, triethylamine, ethyl Diamine, tetramethylethylenediamine, hexamethylenediamine, N, N-dimethylpropan-2-amine, aniline, N, N-diisopropylethylamine, 2,4-hexadiynylamine, 2,4-heptadiynylamine, 2,4- Octadiynylamine, 2,4-decadiynylamine, 2,4-dodecadiynylamine, 2,4-tetradecadiynylamine, 2,4-pentadecadiynylamine, 2,4-hexadecadiynylamine, 2,4 -Octadecadiynylamine, 2,4-nonadecadiynylamine, 10,12-tetradecadiynylamine, 10,12-pentadecadiynylamine, 10,12-hexadecadiynylamine, 10,12-heptadecadiynylamine 10,12-octadecadiynylamine, 10,12-tricosadiynylamine, 10,12-pentacosadiynylamine, 10,12-hexacosadiynylamine, 10,12-heptacosadiynylamine, 1 0,12-octacosadiynylamine, 10,12-nonacosadiynylamine, 2,4-hexadiynyldiamine, 3,5-octadiynyldiamine, 4,6-decadiynyldiamine, 8,10-octa Examples include decadiynyldiamine, stearic acid amide, palmitic acid amide, lauric acid lauryl amide, oleic acid amide, oleic acid diethanolamide, oleic acid lauryl amide, and the like.

  The organic substance covering the metal nanoparticles preferably has a molecular structure in which by-products are easily decomposed at a low temperature when detached from the metal surface. Although details will be described later, it is preferable to use organic substances that cover the metal nanoparticles as a matrix and the metal nanoparticles as an aggregate having the same degree of polarity. This is because the dispersibility of each metal nanoparticle in the organic dispersion medium can be made comparable by coating with an organic substance having the same polarity. In addition, the degree of polarity can be investigated by dispersing in low polarity toluene or high polarity water.

  The mass ratio of the metal X in the bonding material according to the present invention is preferably in the range of more than 0 and less than 1 with respect to the mass of Ag in the matrix phase. More preferably, it is larger than 0 and not larger than 0.25 (details will be described later).

  As a method of mixing Ag nanoparticles whose surface is coated with organic substances and metal X nanoparticles whose surface is coated with organic substances, a dispersion medium having the same polarity as both organic substances is used. The method of dispersing and mixing in the most simple and preferred. As specific means for mixing, for example, general means such as a three-roll method, a stirring vibrator, and a stirrer can be used. On the other hand, examples of the dispersion medium with small polarity include toluene and α-terpineol. Examples of the dispersion medium with large polarity include water. Examples of intermediates include primary alcohols and triethylene glycol. Is mentioned.

  The bonding material composed of metal X nanoparticles and Ag nanoparticles whose surfaces are coated with an organic substance may be used as it is, but in order to facilitate supply (for example, coating or printing) to a bonding portion of an electronic member. In addition, it is also preferable to use ink, paste, or sheet. When used as an ink or paste, water or an organic solvent may be added as a dispersion medium. Examples of the dispersion medium include methanol, ethanol, propanol, ethylene glycol, triethylene glycol, terpineol, water, hexane, tetrahydrofuran, toluene, cyclohexane, polyvinyl alcohol, polyacrylonitrile, polyvinyl pyrrolidone, polyethylene glycol, and the like. Examples of commercially available solvents include Dispersic 160, Dispersic 161, Dispersic 162, Dispersic 163, Dispersic 166, Dispersic 170, Dispersic 180, Dispersic 182, Dispersic 184, Dispersic 190 ( Above, Big Chemie Japan Co., Ltd., MegaFuck F-479 (Dainippon Ink Chemical Co., Ltd., MegaFuck: registered trademark), Sol Sparse 20000, Sol Sparse 24000, Sol Sparse 26000, Sol Sparse 27000, Sol Sparse 28000 (above, Fuji Polymeric dispersants such as “Solsperse” (registered trademark) manufactured by Film Imaging Colorant Co., Ltd. can be used.

  The ink-like / paste-like bonding material is, for example, a method in which ink or paste is ejected from a fine nozzle by an ink jet method and applied to a portion where an electronic member is to be bonded, or a metal mask or mesh-shaped mask having an opening to be applied is used. It is possible to apply and print by appropriately combining known methods according to the area and shape of the part to be joined, such as a method of using and applying only to a necessary part.

  Moreover, it can process into a sheet form by pressure molding and can be used as a joining material. At this time, moldability is improved by adding an organic substance that is solid at room temperature, such as myristyl alcohol, cetyl alcohol, stearyl alcohol, capric acid, undecanoic acid, lauric acid, and myristic acid. As described above, it is preferable to adjust the bonding material to an ink-like / paste-like or sheet material in order to facilitate application / printing at the joining portion of the electronic member, but at this time, the metal nanoparticles in the bonding material The content is preferably 60 to 99 mass%.

  As described above, a bonding material including Ag nanoparticles whose individual particle surfaces are coated with organic substances and metal X nanoparticles whose individual particle surfaces are coated with organic substances as described above is disposed between the electronic members to be bonded. By the heat treatment, the organic component in the bonding material is removed and the Ag nanoparticles and the metal X nanoparticles are sintered, and the composite metal sintered body in which the metal X is dispersed in the Ag matrix according to the present invention (bonding) Layer). Thereby, this electronic member can be joined. At this time, metal bonding is also obtained at the interface between the bonding layer and the electronic member.

  Regarding the temperature in the heat treatment, it is preferably performed at 150 to 400 ° C. (details will be described later). If the temperature is lower than 150 ° C., removal of organic components in the bonding material may be incomplete, and if the temperature exceeds 400 ° C., problems may occur from the viewpoint of heat resistance of the electronic member. Since the upper limit temperature is due to the heat resistance of the electronic member to be joined, the upper limit temperature is not limited to 400 ° C. when the electronic member to be joined permits.

  In addition, it is preferable to pressurize the joint with a pressure greater than 0 together with the heat treatment. By applying pressure during the heat treatment, it is possible to compensate for the volume shrinkage associated with the decomposition and discharge of the organic component and the sintering of the metal nanoparticles. Thereby, the joint strength of the joint is improved. The applied pressure is preferably less than 10 MPa. More preferably, it is 5 MPa or less. This is because electronic members to be joined (for example, semiconductor chips and wirings and electrodes formed on the upper surface thereof) are generally vulnerable to physical deformation. As shown in Table 1, when a pressure of 10 MPa or more was applied, the semiconductor chip to be bonded might be damaged.

  The outermost surface of the electronic member that comes into contact with the bonding material according to the present invention is preferably metallized with a metal species that facilitates metal bonding with Ag, for example, Au, Pt, Pd, Ag, Cu, Ni, or those A material selected from these alloys can be used (details will be described later).

  Since the bonding material according to the present invention becomes a composite metal sintered body (bonding layer) by heat treatment and exhibits properties as a bulk body, its melting point is much higher than the heat treatment temperature (sintering temperature). It will be expensive. The current mounting method in the semiconductor device manufacturing process is mainly to use hierarchical solder, and the solder used in the primary mounting is the Sn-Ag-Cu solder mainly used in the secondary mounting. It is required to have a melting point equal to or higher than the mounting temperature (230 to 260 ° C.). For this reason, high-temperature solder (lead content: about 96%, melting point: about 300 ° C.) is often used. From the viewpoint of this melting point, the metal X is a simple substance selected from the group consisting of Au, Cu, Ni, Ti, Pt, and Pd, or an alloy thereof, whose melting point exceeds 300 ° C. even when alloyed with Ag. Preferably there is. This makes it possible to make the high-temperature solder lead-free, which is difficult at present.

  On the other hand, in addition to the above-mentioned requirements for heat resistance (melting point), high heat dissipation (high thermal conductivity) is required for the joint portion of the electronic member. For example, in a non-insulated semiconductor device which is one of power semiconductor devices used for an inverter or the like, the electrode of the semiconductor device is an electrode for passing a current and also a member for fixing a semiconductor element. More specifically, the fixing member (base material) of the power transistor often serves also as a collector electrode, and a current of several amperes or more flows when the semiconductor device is in operation. In order to operate such a semiconductor device safely and stably, it is necessary to efficiently dissipate heat generated during the operation of the semiconductor device to the outside of the package and to secure connection reliability of the junction. For this reason, high heat dissipation is required in addition to heat resistance including long-term reliability.

  As described above, the bonding material according to the present invention exhibits properties as a bulk body by becoming a composite metal sintered body (bonding layer) by heat treatment, so that it is high in addition to excellent heat resistance. It has heat dissipation (high thermal conductivity) (specific examples will be described later). In the composite metal sintered body according to the present invention, the use of Cu or Ni as the dispersed phase does not form an intermetallic compound with Ag as the matrix phase, and the solidus temperature due to the eutectic is 770 ° C. or higher. It is particularly preferable for some reason.

  The bonding layer according to the present invention is characterized by having a sintered structure of metal crystals, not a melt-solidified structure such as brazing, welding, or eutectic. In the bonding layer formed at a sintering temperature of 400 ° C. or less, Ag and the metal X are not alloyed as a whole, so that one of them functions as the other grain growth barrier layer and the crystal grain size is fine ( For example, it is possible to obtain a particle size of 1 μm or less. Fine control of crystal grains (increasing grain boundaries and different material interfaces) improves joint toughness and fracture toughness.

  In the bonding layer, not only the matrix phase but also the disperse phase is formed by sintering the metal X nanoparticles, so that the shape reflects the sintering. Further, regarding the metal X nanoparticles constituting the dispersed phase, a natural oxide film may exist on the particle surface before the sintering. Although details will be described later, this is because the natural oxide film is reduced during the heat treatment due to the presence of the organic substance covering the metal X nanoparticles and Ag nanoparticles constituting the dispersed phase.

  Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the embodiments described here, and may be combined as appropriate.

  In Example 1, the effect of organic coating on the surface of the metal X nanoparticles mixed as an aggregate was examined. As bonding material (4), Ag nanoparticles with a particle size of 1 to 100 nm coated with organic substances on the surface of each particle and Cu nanoparticles with an average particle diameter of 0.2 μm coated with organic substances on the surface of each particle are mixed. The prepared bonding material was prepared. At this time, similarly to the bonding materials (1) and (2) described above, the organic substance covering the Ag nanoparticles is an amine, the organic substance covering the Cu nanoparticle is a carboxylic acid, and the dispersion medium when mixing is water. Was used. Moreover, the joining material which changed mass ratio of Cu particle | grains with respect to Ag particle | grains was prepared. The test piece to be joined using the above-mentioned joining material is made of oxygen-free copper, and is a disk-shaped test piece having a diameter of 5 mm and a thickness of 2 mm on the upper side and a disk shape having a diameter of 10 mm and a thickness of 5 mm on the lower side. A test piece was obtained.

  After installing the bonding material (4) between the above-mentioned upper and lower test pieces, only water was removed by applying a vacuum drying treatment. Next, the joint was joined by performing a heat treatment while applying pressure. The bonding conditions are a maximum heating temperature (bonding temperature) of 300 to 400 ° C., a bonding time of 150 s, and a bonding pressure of 2.5 MPa. The joining time is the sum of the temperature rise from room temperature to the joining temperature and the time kept at the maximum heating temperature.

  Next, the joint strength under pure shear stress was measured using a joint joint produced under the above joining conditions. For the shear test, a bond tester (manufactured by Seishin Shoji Co., Ltd., SS-100KP, maximum load 100 kg) was used. The shear rate was 30 mm / min, the test piece was broken with a shearing tool, and the maximum load at the time of breaking was measured. The value obtained by dividing the maximum load thus obtained by the joint area was taken as the shear strength of the joint joint.

  FIG. 4 is a graph showing the relationship between the mass ratio of Cu nanoparticles to Ag nanoparticles and the normalized shear strength in the bonding material of (4). As described above, the normalized shear strength is standardized with the shear strength in the case of the bonding material (3) (only Ag nanoparticles, mass ratio of Cu particles = 0) being 1. As is clear from comparison between FIG. 4 and FIG. 1, it can be seen that the bonding material (4) has a higher normalized shear strength than the bonding material (1) at any bonding temperature. It can also be seen that the normalized shear strength is greater than 1 when the Cu nanoparticle mass ratio of the bonding material (4) is 0 to 1 (at least 0.25) when the bonding temperature is 400 ° C.

  The difference between the bonding material of the above (4) and the bonding material of the above (1) is whether or not the individual surfaces of Cu nanoparticles mixed as an aggregate are covered with an organic substance. From the result of FIG. 4, when forming the connection layer by the composite metal sintered body, the aggregates 304 (Cu) as shown in FIG. It is considered that the bonding strength (metal bonding property) at the interface portions 305 and 306 between the particles) and the interfaces 307 and 308 between the aggregate 304 and the Cu electrodes 301 and 302 has been greatly improved. That is, the examination of Example 1 revealed that it is important for the metal X nanoparticles mixed with the bonding material to cover at least the surface of each particle with an organic substance.

  In Example 2, the polarity magnitude of the organic substance covering the surface of each nanoparticle was examined. As the bonding material (5), Ag nanoparticles having a particle diameter of 1 to 100 nm each having a particle surface coated with an amine organic substance and Cu nano particles having an average particle diameter of 0.2 μm having each particle surface coated with a carboxylic acid organic substance. A bonding material mixed with particles was prepared. At this time, toluene was used as a dispersion medium when mixing. Moreover, the joining material which changed mass ratio of Cu particle | grains with respect to Ag particle | grains was prepared. Then, the joint joint was produced on the conditions and methods similar to Example 1, and the junction strength was measured.

  The result of shear strength is shown in FIG. FIG. 5 is a graph showing the relationship between the mass ratio of Cu nanoparticles to Ag nanoparticles and the normalized shear strength in the bonding material of (5) above. As is clear from comparison between FIG. 5 and FIG. 4, it can be seen that the bonding material (5) has a higher normalized shear strength than the bonding material (4) at any bonding temperature. . It can also be seen that the normalized shear strength is greater than 1 when the Cu nanoparticle mass ratio of the bonding material of (5) is 0 to 1.

  The reason why the above results were obtained can be considered as follows. Cu nanoparticles coated with carboxylic acid organic materials used in bonding materials (4) and (5) and Ag nanoparticles coated with amine organic materials used in bonding materials (5) are nonpolar dispersions such as toluene. Dispersibility is good with respect to a medium (or a dispersion medium with small polarity). Therefore, since the bonding material (5) used toluene as a dispersion medium, it is considered that homogeneous mixing was obtained in the dispersion medium. On the other hand, the Ag nanoparticles coated with the amine organic material used in the bonding material (4) have good dispersibility with respect to a polar dispersion medium such as water (or a dispersion medium having a large polarity). On the other hand, since the bonding material (4) used water as a dispersion medium, it is considered that imbalance occurred in mixing in the dispersion medium.

  When the microstructure of the bonding layer of each sample was observed with a scanning electron microscope (SEM), in the case of a combination of organic substances having different polarities (for example, bonding material (4)), it aggregated into a part of the dispersed phase of Cu nanoparticles. Segregation, which is considered to be caused by, was observed. On the other hand, in the case of a combination of organic substances having the same polarity (joining material (5)), the structure was such that the Cu dispersed phase was dispersed substantially uniformly in the Ag matrix. From the examination of Example 2, it has been clarified that it is important to select a combination of the organic substances used for preparing the bonding material so that the polarities thereof are approximately the same.

  In Example 3, the bonding temperature in the bonding material according to the present invention was examined. The heat measurement was performed in the atmosphere using a thermobalance / differential thermal analyzer (TG / DTA6200, manufactured by Seiko Instruments Inc.) at a temperature rising rate of 10 ° C./min. FIG. 6 shows Ag nanoparticles having a particle size of 1 to 100 nm coated with amine organic substances on the individual particle surfaces and Cu nanoparticles having an average particle diameter of 0.2 μm coated with carboxylic acid organic substances on the individual particle surfaces. It is a thermal analysis result with respect to the joining material mixed by mass ratio "Ag: Cu = 1: 0.25". As shown in FIG. 6, an exothermic peak was detected at about 150 ° C. to about 300 ° C., and weight loss was observed with this exothermic peak. Moreover, the weight was almost constant thereafter.

  From these results, it was considered that the exothermic peak and the weight reduction were caused by the oxidative decomposition of the organic substances covering the individual particle surfaces. Furthermore, when the sample after measurement was observed with TEM (transmission electron microscope), sintering of metal nanoparticles was confirmed. From the examination of Example 3, it became clear that the bonding temperature is desirably 150 ° C. or higher.

In Example 4, the surface properties of Cu nanoparticles (natural oxide film present on the surface) were examined. FIG. 7 shows the result of XRD measurement (X-ray diffractometer: RU200B, manufactured by Rigaku Corporation) on Cu nanoparticles having an average particle diameter of 0.2 μm whose individual particle surfaces are coated with carboxylic acid organic substances. . As shown in FIG. 7, a Cu ₂ O peak was detected in addition to the Cu peak. Further, when the Cu nanoparticles were observed by TEM, the presence of a Cu ₂ O layer of about 1 to 5 nm was observed on the surface of the Cu nanoparticles.

Next, Ag nanoparticles having a particle diameter of 1 to 100 nm and the Cu nanoparticles (the surface of which has Cu ₂ O present and the outer surface thereof being coated with a carboxylic acid organic material). A bonding material (6) prepared at a mass ratio of “Ag: Cu = 1: 0.25” was prepared. As the dispersion medium when mixing, toluene having a small polarity was used. Thereafter, a bonded joint was produced at a bonding temperature of 400 ° C., a bonding time of 150 s, and a pressure of 2.5 MPa, and XRD measurement was performed on the bonding layer of the obtained joint. The result is shown in FIG. FIG. 8 shows an example of the result of XRD measurement performed on the bonding layer bonded using the bonding material (6). As shown in FIG. 8, no peak representing the presence of Cu ₂ O detected in the bonding material (6) was detected. This was thought to be due to the reduction of the natural oxide film (for example, Cu ₂ O) by oxidative decomposition of the organic substance coated with Ag nanoparticles and Cu nanoparticles. From the examination of Example 4, it became clear that the metal X nanoparticles to be mixed do not pose a problem even if the surface of the particles has a film having a degree of natural oxidation.

  Whether the interfaces existing in the bonding layer (the interface between the matrix phase and the dispersed phase, the interface between the matrix phase and the electronic member, the interface between the dispersed phase and the electronic member, the interface inside the dispersed phase, etc.) are all metal-bonded In order to investigate, the bonding layer was observed with TEM-EDX (transmission electron microscope-energy dispersive X-ray analyzer). In general, a sintered silver layer formed of Ag nanoparticles is a polycrystalline body when there is no bonding defect such as a void, and its crystal size is about submicron (100 to 1000 nm range). . On the other hand, with respect to the bonding layer according to the present invention, crystal grains whose crystal size was clearly smaller than 10 to 1000 nm and 100 nm were confirmed. The reason was considered that the sintered copper as the dispersed phase functioned as a barrier layer for the grain growth of the sintered silver as the matrix phase.

  In addition, as a result of observation, oxidation is performed at interfaces existing in the bonding layer (interface between matrix phase and dispersed phase, interface between matrix phase and electronic member, interface between dispersed phase and electronic member, interface inside dispersed phase, etc.) The presence of a film or the like was not recognized. On the other hand, it was confirmed that many twins were introduced in these interface regions. These twins are considered to be introduced mainly during sintering and grain growth, and strongly suggest that various interfaces are metal-bonded together with the absence of an oxide film.

  FIG. 9 shows a TEM-EDX quantitative analysis performed on the interface region between sintered silver as a matrix phase and sintered copper as a dispersed phase in the bonding layer bonded using the bonding material (6). It is an example of a result. Concentration changes indicating mutual diffusion were observed in the range of several nm on both sides of the interface (about 5 to 15 nm). In addition, lattice strain was observed in the interface region. It was considered that lattice strain was introduced as a result of both metal lattice bonding and interdiffusion between two different lattice constants (Ag: 0.4086 nm, Cu: 0.3615 nm). That is, it is considered that the interface region forms a metal alloy that is graded and alloyed, and as a result, the grain boundary diffusion of oxygen atoms is inhibited, and the oxidation resistance of the entire joint becomes substantially equal to Ag. (It is thought that the oxidation resistance is improved at least as compared with a sintered body of Cu alone).

  In Example 6, the properties of the outermost surface of the electronic member (bonded electrode) were investigated. As described above, in order to obtain a high joint strength in general, it is important to obtain a metal joint even at the interface between the electronic member and the joining layer. Therefore, an Au layer, an Ag layer, a Cu layer, and a Ni layer were formed as metallization layers on the surface of the test specimen, and the effects were verified. In order to evaluate the joint strength in each metallized layer, joint joints were produced under the same conditions and methods as in Example 1 using the joint material (6), and the joint strength was measured. FIG. 10 is a graph showing the relationship between the bonding temperature and the normalized shear strength in each metallized layer. As shown in FIG. 10, a normalized shear strength of 1 or more was obtained for any metallized layer. In particular, the normalized shear strength of 1.5 or more was obtained in the entire bonding temperature range (300 to 400 ° C.) for the Au layer and the Ag layer, and the Cu layer and the Ni layer in the bonding temperature range of at least 350 ° C. or more. The Pt layer and the Pd layer as the metallized layer are considered to obtain the same results as the Au layer and the Ag layer in consideration of the chemical properties of the elements.

  In Example 7, a semiconductor device according to the present invention will be described. 11A and 11B are schematic views showing an example of the structure of a non-insulated semiconductor device that is one of the semiconductor devices according to the present invention. FIG. 11A is a top view and FIG. It is an AA 'sectional view of). As shown in FIG. 11, a semiconductor element (eg, MOSFET) 101 is mounted on wiring electrodes 102a and 102b formed on a ceramic insulating substrate 102, and the ceramic insulating substrate 102 is mounted on a base material 103. The material 103 is housed in an epoxy resin case 105. The electrode terminal 110 formed on the epoxy resin case 105 and the wiring electrodes 102a and 102b are connected by a bonding wire 104 (for example, an Al wire having a diameter of 300 μm) by a method such as ultrasonic bonding. Further, a gate electrode / emitter electrode (not shown) formed in each semiconductor element 101 and the electrode terminal 110 are also connected by a bonding wire 104. The epoxy resin case 105 is filled with a silica ketone resin 107, and an epoxy resin lid 106 is provided on the case.

  Here, the base material 103 and the ceramic insulating substrate 102 are bonded together by a bonding layer 108 formed using the bonding material (7) according to the present invention. On the wiring electrode 102a formed on the ceramic insulating plate 102, eight MOSFET elements 101 are bonded via a bonding layer 109 formed of a bonding material (7). Further, the temperature detection thermistor element 111 is mounted on the wiring electrode 102b via the bonding layer 109. Note that the bonding material (7) is an Ag nanoparticle having a particle diameter of 1 to 1000 nm in which each particle surface is coated with a carboxylic acid organic material, and each particle surface is coated with an organic material composed of an amine and a carboxylic acid. It is a paste-like bonding material in which Cu nanoparticles having a particle diameter of 1 to 1000 nm are mixed at a mass ratio “Ag: Cu = 1: 0.1” and further dispersed in α-terpineol.

  Bonding by the bonding layers 108 and 109 was performed in the following procedure. First, the bonding material (7) was applied to predetermined positions on the wiring electrode 102a (Cu electrode with Ni plating on the outermost surface) and the base material 103 of the ceramic insulating plate 102, respectively. Next, the ceramic insulating plate 102 and the semiconductor element 101 (Au plating was applied to the outermost surface of the terminal) were placed on the applied bonding material (7). Thereafter, bonding was performed under the bonding conditions of a bonding temperature of about 300 ° C., a bonding time of 300 s, and a pressure of 1 MPa.

  The epoxy resin case 105 and the base material 103 are fixed using a silica ketone adhesive resin (not shown). The lid 106 made of epoxy resin is provided with a recess 106 ′, the electrode terminal 110 is provided with a hole 110 ′, and a screw (not shown) for connecting the insulating semiconductor device to an external circuit is provided. It can be installed. The base material 103 and the electrode terminal 110 are obtained by performing Ni plating on the surface of a Cu plate that has been punched into a predetermined shape in advance.

  FIG. 12 is an enlarged schematic cross-sectional view of the semiconductor element 101 mounting portion shown in FIG. 11 before the bonding process. As shown in FIG. 12, a paste-like bonding material (7) is disposed between the base material 103 and the ceramic insulating substrate 102, and between the wiring electrode 102a formed on the ceramic insulating plate 102 and the semiconductor element 101. Also, a paste-like bonding material (7) is disposed. At this time, a water-repellent film 122 is applied on the base material 103 so as to define a mounting region of the ceramic insulating substrate 102 in order to prevent the paste from flowing out when the paste-like bonding material is applied. Similarly, a water-repellent film 121 is applied on the ceramic insulating substrate 102 so as to define the mounting area of the semiconductor element 101 so as to prevent outflow when applying the paste.

  FIG. 13 is a schematic perspective view showing another structural example of the semiconductor device according to the present invention. As shown in FIG. 13, a ceramic insulating substrate 202 is mounted on a base material 203, a semiconductor element 201 is mounted on a wiring electrode 202a formed on the ceramic insulating substrate 202, and an emitter electrode of the semiconductor element 201 serves as a connection terminal. The wiring electrode 202 b formed on the ceramic insulating substrate 202 is connected via the 204. The base material 203, the wiring electrodes 202a and 202b, and the connection terminal 204 are obtained by performing Ni plating on the surface of the Cu plate and applying Ag plating thereon.

  14 is an enlarged schematic cross-sectional view of the semiconductor element mounting portion shown in FIG. 13 before the bonding process. The present invention is provided between the wiring electrode 202a formed on the ceramic insulating substrate 202 and the semiconductor element 201, between the emitter electrode of the semiconductor element 201 and the connection terminal 204, and between the electrode wiring 202b and the connection terminal 204, respectively. The bonding material (8) according to the above is arranged. Note that the bonding material (8) is an Ag nanoparticle having a particle diameter of 5 to 100 nm in which each particle surface is coated with an organic substance composed of amines and alcohols, and each particle surface is composed of amines and carboxylic acids. It is a bonding material obtained by mixing Cu nanoparticles with a particle size of 30 to 500 nm coated with an organic substance at a mass ratio of “Ag: Cu = 1: 0.25”, and further pressing and processing into a sheet.

  After placement and mounting as shown in FIG. 14, joining was performed under the joining conditions of a joining temperature of about 300 ° C., a joining time of 300 s, and a pressure of 0.5 MPa. As a result, a connection layer (composite metal sintered layer) in which the dispersed Cu phase was uniformly dispersed in the Ag matrix phase was formed, and the joining was completed. In the semiconductor device of this embodiment, by using the connection terminal 204 having a large wiring width, a large current can flow not only to the collector electrode but also to the emitter electrode portion. At this time, since the connection layer according to the present invention has good heat resistance, high electrical conductivity, and high thermal conductivity, the semiconductor device can be operated safely and stably.

  In the above embodiment, the case of the MOSFET has been described as an example of the semiconductor device, but the semiconductor device according to the present invention is not limited thereto. For example, when mounting an LED (particularly a high-brightness LED, etc.) on a substrate, bonding using the bonding material of the present invention significantly improves heat dissipation compared to conventional solders and heat conductive adhesives. This is preferable.

It is a graph which shows the relationship between the mass ratio of Cu nanoparticle with respect to Ag nanoparticle in a bonding material (1), and normalized shear strength. It is a graph which shows the relationship between the mass ratio of Cu particle | grains with respect to Ag nanoparticle in a bonding | jointing material (2), and normalized shear strength. It is a model figure showing the section of Cu electrode joined part. It is a graph which shows the relationship between the mass ratio of Cu nanoparticle with respect to Ag nanoparticle in a bonding material (4), and normalized shear strength. It is a graph which shows the relationship between the mass ratio of Cu nanoparticle with respect to Ag nanoparticle in a bonding | jointing material (5), and normalized shear strength. The mass ratio of Ag nanoparticles with a particle size of 1 to 100 nm with the surface of each particle coated with an amine organic substance and Cu nanoparticles with an average particle size of 0.2 μm with the surface of each particle coated with a carboxylic acid organic substance is `` Ag : Cu = 1: 0.2 ”is a thermal analysis result for the bonding material mixed. It is the result of having performed the XRD measurement with respect to Cu nanoparticle with an average particle diameter of 0.2 micrometer by which each particle | grain surface was coat | covered with carboxylic acid organic substance. It is an example of the result of having performed the XRD measurement with respect to the joining layer joined using the joining material (6). An example of the result of quantitative analysis by TEM-EDX for the interface region between sintered silver as the matrix phase and sintered copper as the dispersed phase in the bonding layer bonded using the bonding material (6) It is. It is a graph which shows the relationship between the joining temperature in each metallization layer in the joining strength with each electrode produced using the joining material (6), and the normalized shear strength. FIG. 11A is a schematic view showing a structural example of a non-insulated semiconductor device which is one of the semiconductor devices according to the present invention, FIG. 11A is a top view, and FIG. It is A 'sectional drawing. FIG. 12 is an enlarged schematic cross-sectional view of the semiconductor element mounting portion shown in FIG. 11 before the bonding process. It is the isometric view schematic diagram which showed the other structural example of the semiconductor device which concerns on this invention. FIG. 14 is an enlarged schematic cross-sectional view of the semiconductor element mounting portion shown in FIG. 13 before a bonding process.

101 ... semiconductor element, 102 ... ceramic insulating substrate, 102a, 102b ... wiring electrode,
103 ... Base material, 104 ... Bonding wire, 105 ... Epoxy resin case,
106 ... Epoxy resin lid, 106 '... concave, 107 ... silica ketone resin,
108, 109 ... bonding layer, 110 ... electrode terminal, 110 '... hole, 111 ... thermistor element for temperature detection,
121, 122 ... water repellent film,
201 ... semiconductor element, 202 ... ceramic insulating substrate, 202a, 202b ... wiring electrode,
203 ... Base material, 204 ... Connection terminal,
300 ... Bonding material, 301,302 ... Cu electrode, 303 ... Sintered silver, 304 ... Aggregate,
305, 306 ... interface part between aggregates, 307, 308 ... interface part with Cu electrode,
309 ... interfacial part between sintered silver and aggregate, 310,311 ... interfacial part between sintered silver and Cu electrode.

Claims (8)

A semiconductor device in which electronic members are electrically connected via a bonding layer,
The bonding layer includes an Ag matrix, and a dispersed phase composed of a metal X dispersed in the Ag matrix and having a hardness higher than Ag.
The Ag matrix and the metal X dispersed phase are metal bonded to each other,
The Ag matrix and the outermost surface of the electronic member are metal bonded to each other,
The metal X dispersed phase and the outermost surface of the electronic member are metal bonded to each other,
The metal X dispersed phase includes crystal grains of 1 μm or less,
The semiconductor device, wherein the Ag matrix includes crystal grains smaller than 100 nm. The semiconductor device according to claim 1,
The metal X dispersed phase is composed of a plurality of crystal grains,
The semiconductor device, wherein the plurality of crystal grains are metal-bonded without intervening an oxide film. The semiconductor device according to claim 1 or 2,
A semiconductor device, wherein a mass ratio of the metal X dispersed phase to the Ag matrix is larger than 0 and smaller than 1. The semiconductor device according to any one of claims 1 to 3,
An interdiffusion layer resulting from a crystal sandwiching the interface is formed in a junction interface region of the metal junction. The semiconductor device according to any one of claims 1 to 4,
The metal X dispersed phase is substantially a sphere or a substantially ellipsoid, and when the metal X dispersed phase can be regarded as a substantially sphere, the diameter thereof, and when the metal X dispersed phase can be regarded as a substantially ellipsoid, the major axis thereof, A semiconductor device characterized by being in a range of “T / (2 × 10 ⁴ ) to T / 2” with respect to the thickness T of the bonding layer. The semiconductor device according to claim 5,
A semiconductor device, wherein a distance from one dispersed phase to the nearest dispersed phase in the metal X dispersed phase is in a range of “T / (4 × 10 ⁴ ) to T / 2”. The semiconductor device according to any one of claims 1 to 6,
The outermost surface of the electronic member is a metallized layer formed on the surface of the electronic member,
The metallized layer is made of any one of Au, Pt, Pd, Ag, Cu, and Ni, or an alloy thereof. The semiconductor device according to claim 1,
The semiconductor device, wherein the metal X is Cu and / or Ni.

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