Semiconductor device and preparation method thereof

Abstract

The invention relates to a semiconductor device and a preparation method thereof. The preparation method of the semiconductor device comprises the following steps: forming a first metal bonding layer on the surface of the semiconductor device; forming a second metal bonding layer on the surface of the diamond heat dissipation layer; respectively coating nano-silver paste on the surfaces of the first metal bonding layer and the second metal bonding layer; the first metal bonding layer and the second metal bonding layer are arranged on the opposite surfaces of the foamy copper layer, the nano-silver paste and the foamy copper layer form a compound layer through heating treatment, and the material of the compound layer comprises Ag2Cu3. According to the preparation method of the semiconductor device, the semiconductor device with the diamond heat dissipation layer and good heat dissipation effect can be prepared. Meanwhile, the preparation method has low requirements on the surface roughness of the diamond, the diamond does not need to be polished, and the preparation difficulty is low.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor devices, and in particular to a semiconductor device and a method for preparing the same. Background Art

[0002] Diamond material has a high thermal conductivity and can be used as a heat dissipation layer for semiconductor devices. The traditional method for preparing a diamond heat dissipation layer includes epitaxially growing a diamond heat dissipation layer on a chip, and epitaxially growing a semiconductor material on the diamond heat dissipation layer to prepare a chip. However, the above method has the problem that the preparation temperature is high and the chip is easily damaged. Therefore, the chip and the diamond heat dissipation layer can be integrated by a chip-diamond wafer bonding method. In the traditional chip-diamond wafer bonding preparation method, the surface roughness of the diamond needs to be reduced. However, it is difficult to polish the diamond to reduce its surface roughness. Summary of the invention

[0003] Based on this, it is necessary to provide a semiconductor device and a method for preparing the same. The method for preparing the semiconductor device of the present application can prepare a semiconductor device having a diamond heat dissipation layer and good heat dissipation effect. At the same time, the above preparation method does not require excessive surface roughness of the diamond, and does not need to polish the diamond, and the preparation difficulty is relatively low.

[0004] In a first aspect, the present application provides a method for preparing a semiconductor device, comprising the following steps:

[0005] forming a first metal bonding layer on the surface of the chip body;

[0006] forming a second metal bonding layer on the surface of the diamond heat dissipation layer;

[0007] Coating nano silver paste on the surfaces of the first metal bonding layer and the second metal bonding layer respectively;

[0008] The first metal adhesive layer and the second metal adhesive layer are arranged on opposite surfaces of the foam copper layer, and the nano silver paste and the foam copper layer are subjected to heat treatment to form a compound layer, wherein the material of the compound layer includes Ag2Cu3.

[0009] In some embodiments, the heating treatment is performed at a temperature of 100°C to 200°C.

[0010] In some embodiments, the pores in the copper foam layer have a pore size of 50 nm to 150 nm.

[0011] In some embodiments, the thickness of the copper foam layer is 10 μm to 50 μm.

[0012] In some embodiments, the nano silver paste includes a dispersion medium and silver nano particles dispersed in the dispersion medium.

[0013] In some embodiments, the silver nanoparticles have a particle size of 30 nm to 80 nm.

[0014] In some embodiments, the dispersion medium includes at least one of ethylene glycol butyl ether acetate and diethylene glycol butyl ether acetate.

[0015] In some embodiments, the thickness of the nano silver paste coated on the surface of the first metal bonding layer is 10 μm-50 μm.

[0016] In some embodiments, the thickness of the nano silver paste coated on the surface of the second metal bonding layer is 10 μm-50 μm.

[0017] In some embodiments, during the process of forming a compound layer between the nano silver paste and the foam copper layer by heat treatment, the silver in the nano silver paste completely fills the pores of the foam copper.

[0018] In some embodiments, the first metal bonding layer is prepared by magnetron sputtering and / or evaporation.

[0019] In some embodiments, the material of the first metal bonding layer includes at least one of titanium, chromium, nickel and tungsten.

[0020] In some embodiments, the thickness of the first metal bonding layer is 5 nm to 50 nm.

[0021] In some embodiments, the second metal bonding layer is prepared by magnetron sputtering and / or evaporation.

[0022] In some embodiments, the material of the second metal bonding layer includes at least one of titanium, chromium, nickel and tungsten.

[0023] In some embodiments, the thickness of the second metal bonding layer is 5 nm to 50 nm.

[0024] In some embodiments, the material of the diamond heat dissipation layer includes at least one of single crystal diamond, polycrystalline diamond, amorphous diamond and diamond-metal composite material.

[0025] In a second aspect, the present application provides a semiconductor device, comprising a diamond heat dissipation layer, a first metal bonding layer, a compound layer, a first metal bonding layer and a chip body stacked in sequence; the material of the compound layer comprises Ag2Cu3.

[0026] In the preparation method of the semiconductor device described above, during the heat treatment process, the nanosilver particles in the nanosilver paste are melted by heat and can enter the pores of the foamed copper and react to form Ag2Cu3 compounds. The Ag2Cu3 compound can form a metallurgical connection with the first metal bonding layer and the second metal bonding layer. In the preparation method of the semiconductor device of the present application, the first metal bonding layer, the second metal bonding layer and the compound layer all have good thermal conductivity, that is, the preparation method of the semiconductor device described above can prepare a semiconductor device with good heat dissipation effect. At the same time, the preparation method described above does not need to require too much additional surface roughness of the diamond, and does not need to polish the diamond, and the preparation difficulty is relatively low.

[0027] Furthermore, the Ag2Cu3 compound has a high melting point, which can improve the heat resistance of the heat dissipation channel. By controlling the pore size of the foamed copper, the grain size of the generated Ag2Cu3 compound can be controlled to improve the shear resistance of the bonding interface. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of a structure in which a first metal bonding layer is formed on the surface of a chip body and a second metal bonding layer is formed on the surface of a diamond heat dissipation layer, provided in an embodiment of the present application, wherein: Figure 1 a is a schematic diagram of a structure in which a first metal bonding layer is formed on the surface of the chip body. Figure 1 b is a schematic diagram of the structure of forming a second metal bonding layer on the surface of the diamond heat dissipation layer;

[0029] Figure 2 The schematic diagram is a structural diagram of coating nano silver paste on the surfaces of the first metal bonding layer and the second metal bonding layer, wherein: Figure 2 a is a schematic diagram of the structure of coating nano silver paste on the surface of the first metal bonding layer, Figure 2 b is a schematic diagram of the structure of coating nano silver paste on the surface of the second metal bonding layer;

[0030] Figure 3 A schematic diagram of a structure in which a first metal bonding layer and a second metal bonding layer are disposed on opposite surfaces of a foam copper layer;

[0031] Figure 4 It is a schematic diagram of the structure of forming a compound layer by heating the nano silver paste and the foam copper layer.

[0032] Description of reference numerals:

[0033] 10. Chip body; 20. First metal bonding layer; 30. Diamond heat dissipation layer; 40. Second metal bonding layer; 50. Nano silver paste; 60. Foam copper layer; 70. Compound layer. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0036] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0037] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0038] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0039] Reference Figure 1~Figure 4As shown, an embodiment of the present application provides a method for preparing a semiconductor device, comprising the following steps:

[0040] Forming a first metal bonding layer 20 on the surface of the chip body 10;

[0041] forming a second metal bonding layer 40 on the surface of the diamond heat dissipation layer 30;

[0042] Coating nano silver paste 50 on the surfaces of the first metal bonding layer 20 and the second metal bonding layer 40 respectively;

[0043] The first metal bonding layer 20 and the second metal bonding layer 40 are disposed on opposite surfaces of the copper foam layer 60 , and the nano silver paste 50 and the copper foam layer 60 are subjected to a heat treatment to form a compound layer 70 , wherein the material of the compound layer 70 includes Ag 2 Cu 3 .

[0044] In the method for preparing the semiconductor device described above, during the heat treatment process, the nanosilver particles in the nanosilver paste 50 are melted by heat and can enter the pores of the foamed copper and react to form Ag2Cu3 compounds. The Ag2Cu3 compound can form a metallurgical connection with the first metal bonding layer 20 and the second metal bonding layer 40. In the method for preparing the semiconductor device of the present application, the first metal bonding layer 20, the second metal bonding layer 40 and the compound layer 70 all have good thermal conductivity, that is, the method for preparing the semiconductor device described above can prepare a semiconductor device with good heat dissipation effect. At the same time, the above preparation method does not need to require too much additional surface roughness of the diamond, and there is no need to polish the diamond, so the preparation difficulty is relatively low.

[0045] Furthermore, the Ag2Cu3 compound has a high melting point, which can improve the heat resistance of the heat dissipation channel. By controlling the pore size of the foamed copper, the grain size of the generated Ag2Cu3 compound can be controlled to improve the shear resistance of the bonding interface.

[0046] It is understandable that the chip body 10 can be any conventional semiconductor chip in the art. For example, it can be a silicon-based semiconductor chip or a gallium nitride-based semiconductor chip. Foam copper is a material in which a large number of connected or unconnected holes are evenly distributed in a copper matrix.

[0047] In some embodiments, a method for preparing a semiconductor device comprises the following steps:

[0048] S10 : forming a first metal adhesive layer 20 on the surface of the chip body 10 ; and forming a second metal adhesive layer 40 on the surface of the diamond heat dissipation layer 30 .

[0049] Reference Figure 1 As shown, Figure 1The schematic diagram is a structural diagram of forming a first metal bonding layer 20 on the surface of a chip body 10 and forming a second metal bonding layer 40 on the surface of a diamond heat dissipation layer 30, wherein: Figure 1 FIG. a is a schematic diagram showing a structure of forming a first metal bonding layer 20 on the surface of the chip body 10. Figure 1 FIG. b is a schematic structural diagram of forming a second metal bonding layer 40 on the surface of the diamond heat dissipation layer 30 .

[0050] In some embodiments, the first metal bonding layer 20 is prepared by magnetron sputtering and / or evaporation.

[0051] In some embodiments, the material of the first metal bonding layer 20 includes at least one of titanium, chromium, nickel and tungsten.

[0052] In some embodiments, the thickness of the first metal bonding layer 20 is 5 nm to 50 nm.

[0053] Within the thickness range of the first metal bonding layer 20, a good connection effect between the first metal bonding layer 20 and the chip body 10 and a good heat dissipation effect of the semiconductor device can be achieved simultaneously. Optionally, the thickness of the first metal bonding layer 20 is 5nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm or 50nm, or the thickness of the first metal bonding layer 20 can also be within the range between any two of the above thicknesses.

[0054] In some embodiments, the second metal bonding layer 40 is prepared by magnetron sputtering and / or evaporation.

[0055] In some embodiments, the material of the second metal bonding layer 40 includes at least one of titanium, chromium, nickel and tungsten.

[0056] In some embodiments, the thickness of the second metal adhesion layer 40 is 5 nm to 50 nm.

[0057] Within the thickness range of the second metal bonding layer 40, a good connection effect between the second metal bonding layer 40 and the compound layer 70 and a good heat dissipation effect of the semiconductor device can be achieved simultaneously. Optionally, the thickness of the second metal bonding layer 40 is 5nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm or 50nm, or the thickness of the second metal bonding layer 40 can also be within the range between any two of the above thicknesses.

[0058] In some embodiments, the material of the diamond heat dissipation layer 30 includes at least one of single crystal diamond, polycrystalline diamond, amorphous diamond and diamond-metal composite material.

[0059] The first metal bonding layer 20 and the second metal bonding layer 40 mentioned above can have good thermal conductivity and can form a good bonding effect with the diamond heat dissipation layer 30, the chip body 10 and the compound layer 70, so that the semiconductor device has a good heat dissipation effect.

[0060] S20 : ​​coating the nano silver paste 50 on the surfaces of the first metal bonding layer 20 and the second metal bonding layer 40 .

[0061] Reference Figure 2 As shown, Figure 2 Schematic diagram of the structure of coating the nano silver paste 50 on the surface of the first metal bonding layer 20 and the second metal bonding layer 40, wherein: Figure 2 FIG. a is a schematic diagram of a structure in which a nano silver paste 50 is coated on the surface of the first metal bonding layer 20. Figure 2 FIG. b is a schematic structural diagram of coating the nano silver paste 50 on the surface of the second metal bonding layer 40 .

[0062] In some embodiments, the nano silver paste 50 includes a dispersion medium and silver nano particles dispersed in the dispersion medium.

[0063] In some embodiments, the silver nanoparticles have a particle size of 30 nm to 80 nm.

[0064] Within the range of the particle size of the silver nanoparticles, it is convenient to melt the silver nanoparticles by heating, and then the melted silver enters the pores of the copper foam layer 60 and reacts with the copper foam to generate Ag2Cu3 compounds. Optionally, the particle size of the silver nanoparticles is 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm or 80nm, or the particle size of the silver nanoparticles can also be within the range between any two of the above particle sizes.

[0065] In some embodiments, the dispersion medium includes at least one of ethylene glycol butyl ether acetate and diethylene glycol butyl ether acetate.

[0066] In some embodiments, the nano silver paste 50 further includes polyacrylic acid.

[0067] The polyacrylic acid in the nano silver paste 50 mainly plays the role of improving the viscosity and rheological properties of the nano silver paste 50 , thereby ensuring the printing properties and molding effect of the nano silver paste 50 .

[0068] In some embodiments, the mass ratio of polyacrylic acid to silver nanoparticles is (1-3):10.

[0069] Optionally, the mass ratio of polyacrylic acid to silver nanoparticles is 1:10, 1.2:10, 1.4:10, 1.6:10, 1.8:10, 2:10, 2.2:10, 2.4:10, 2.6:10, 2.8:10 or 3:10, or, the mass ratio of polyacrylic acid to silver nanoparticles may be within the range between any two of the above mass ratios.

[0070] In some embodiments, the molecular weight of the polyacrylic acid is 2,000 to 10,000.

[0071] Optionally, the molecular weight of the polyacrylic acid is 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000 or 10000, or, the molecular weight of the polyacrylic acid may also be within the range between any two of the above molecular weights.

[0072] In some embodiments, the thickness of the nano silver paste 50 coated on the surface of the first metal bonding layer 20 is 10 μm-50 μm.

[0073] Optionally, the thickness of the nano silver paste 50 coated on the surface of the first metal bonding layer 20 is 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm, or, the thickness of the nano silver paste 50 coated on the surface of the first metal bonding layer 20 can also be within the range between any two of the above thicknesses.

[0074] In some embodiments, the thickness of the nano silver paste 50 coated on the surface of the second metal bonding layer 40 is 10 μm-50 μm.

[0075] Optionally, the thickness of the nano silver paste 50 coated on the surface of the second metal bonding layer 40 is 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm, or the thickness of the nano silver paste 50 coated on the surface of the second metal bonding layer 40 may also be within the range between any two of the above thicknesses.

[0076] S30 : disposing the first metal adhesive layer 20 and the second metal adhesive layer 40 on opposite surfaces of the foam copper layer 60 .

[0077] Reference Figure 3 As shown, Figure 3 It is a schematic structural diagram of disposing the first metal bonding layer 20 and the second metal bonding layer 40 on opposite surfaces of the foam copper layer 60 .

[0078] In some embodiments, the pores in the copper foam layer 60 have a pore diameter of 50 nm to 150 nm.

[0079] Within the range of the pore diameter of the pores in the above-mentioned copper foam layer 60, it is convenient for the silver in the nano silver paste 50 to melt and enter the pores of the copper foam layer 60, and the filling effect of the pores of the copper foam layer 60 can be better. Then, the effect of generating Ag2Cu3 compounds can be better. Optionally, the pore diameter of the pores in the copper foam layer 60 is 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm or 150nm, or the pore diameter of the pores in the copper foam layer 60 can also be within the range between any two of the above-mentioned pore diameters.

[0080] In some embodiments, the thickness of the copper foam layer 60 is 10 μm to 50 μm.

[0081] Optionally, the thickness of the copper foam layer 60 is 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm, or the thickness of the copper foam layer 60 may also be within a range between any two of the above thicknesses.

[0082] S40: The nano silver paste 50 and the foam copper layer 60 are subjected to a heating treatment to form a compound layer 70, wherein the material of the compound layer 70 includes Ag2Cu3.

[0083] Reference Figure 4 As shown, Figure 4 It is a schematic structural diagram of forming a compound layer 70 by heating the nano silver paste 50 and the foam copper layer 60.

[0084] In some embodiments, the temperature of the heating treatment is 100°C to 200°C.

[0085] Within the temperature range of the above-mentioned heating treatment, the nanosilver particles can be melted and enter the pores of the foam copper layer 60. The method for preparing the semiconductor device of the present application can achieve the bonding of the chip body 10 and the diamond heat dissipation layer 30 at a relatively low temperature, which can reduce or avoid the damage to the inside of the chip body 10 caused by high temperature, and can improve the reliability of the semiconductor device. Optionally, the temperature of the heating treatment is 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C or 200°C, or the temperature of the heating treatment can also be within the range between any two of the above-mentioned temperatures.

[0086] In some embodiments, during the process of forming the compound layer 70 by heating the nano silver paste 50 and the copper foam layer 60 , the nano silver paste 50 completely fills the pores of the copper foam.

[0087] Silver fills all the pores of the foamed copper to form a Ag2Cu3 compound, which has a better effect.

[0088] Refer again Figure 1 As shown, another embodiment of the present application provides a semiconductor device, including a diamond heat dissipation layer 30, a first metal bonding layer 20, a compound layer 70, a first metal bonding layer 20 and a chip body 10 stacked in sequence; the material of the compound layer 70 includes Ag2Cu3.

[0089] In the semiconductor device, the bonding effect between the diamond heat dissipation layer 30, the first metal bonding layer 20, the compound layer 70, the first metal bonding layer 20 and the chip body 10 is good, and the heat dissipation effect of the diamond heat dissipation layer 30, the first metal bonding layer 20, the compound layer 70, and the first metal bonding layer 20 is good. At the same time, the melting point of the Ag2Cu3 compound is relatively high, which can improve the temperature resistance of the heat dissipation channel.

[0090] In some embodiments, the compound layer 70 has a thickness of 10 μm to 50 μm.

[0091] Optionally, the thickness of the compound layer 70 is 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm or 50 μm, or the thickness of the compound layer 70 may be within a range between any two of the above thicknesses.

[0092] In some embodiments, the first metal bonding layer 20 and the compound layer 70 form a metallurgical connection.

[0093] In some embodiments, the second metal bonding layer 40 and the compound layer 70 form a metallurgical connection.

[0094] In some embodiments, the material of the first metal bonding layer 20 includes at least one of titanium, chromium, nickel and tungsten.

[0095] In some embodiments, the thickness of the first metal bonding layer 20 is 5 nm to 50 nm.

[0096] Optionally, the thickness of the first metal bonding layer 20 is 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm or 50 nm, or the thickness of the first metal bonding layer 20 may also be within a range between any two of the above thicknesses.

[0097] In some embodiments, the material of the second metal bonding layer 40 includes at least one of titanium, chromium, nickel and tungsten.

[0098] In some embodiments, the thickness of the second metal adhesion layer 40 is 5 nm to 50 nm.

[0099] Optionally, the thickness of the second metal bonding layer 40 is 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm or 50 nm, or the thickness of the second metal bonding layer 40 may also be within the range between any two of the above thicknesses.

[0100] In some embodiments, the material of the diamond heat dissipation layer 30 includes at least one of single crystal diamond, polycrystalline diamond, amorphous diamond and diamond-metal composite material.

[0101] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0102] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims, and the description and drawings may be used to interpret the contents of the claims.

Claims

1. A method for preparing a semiconductor device, characterized in that: The steps include: forming a first metal bonding layer on the surface of the chip body; forming a second metal bonding layer on the surface of the diamond heat dissipation layer; Coating nano silver paste on the surfaces of the first metal bonding layer and the second metal bonding layer respectively; The first metal adhesive layer and the second metal adhesive layer are arranged on opposite surfaces of the foam copper layer, and the nano silver paste and the foam copper layer are subjected to heat treatment to form a compound layer, wherein the material of the compound layer includes Ag2Cu3.

2. The method for preparing a semiconductor device according to claim 1, wherein: The temperature of the heating treatment is 100°C to 200°C.

3. The method for preparing a semiconductor device according to claim 1, characterized in that: The pores in the foam copper layer have a pore size of 50 nm to 150 nm; and / or, The thickness of the foam copper layer is 10 μm to 50 μm.

4. The method for preparing a semiconductor device according to claim 1, wherein: The nano silver paste includes a dispersion medium and silver nano particles dispersed in the dispersion medium.

5. The method for preparing a semiconductor device according to claim 4, characterized in that: The particle size of the silver nanoparticles is 30nm to 80nm; and / or, The dispersion medium includes at least one of ethylene glycol butyl ether acetate and diethylene glycol butyl ether acetate.

6. The method for preparing a semiconductor device according to claim 1, wherein: The thickness of the nano silver paste coated on the surface of the first metal bonding layer is 10 μm to 50 μm; and / or, The nano silver paste is coated on the surface of the second metal bonding layer to a thickness of 10 μm to 50 μm.

7. The method for preparing a semiconductor device according to any one of claims 1 to 6, characterized in that: In the process of forming a compound layer between the nano silver paste and the foam copper layer by heating, the silver in the nano silver paste completely fills the pores of the foam copper.

8. The method for preparing a semiconductor device according to any one of claims 1 to 6, characterized in that: The first metal bonding layer is prepared by magnetron sputtering and / or evaporation; and / or, The material of the first metal bonding layer includes at least one of titanium, chromium, nickel and tungsten; and / or, The thickness of the first metal bonding layer is 5nm-50nm; and / or, The second metal bonding layer is prepared by magnetron sputtering and / or evaporation; and / or, The material of the second metal bonding layer includes at least one of titanium, chromium, nickel and tungsten; and / or, The thickness of the second metal bonding layer is 5 nm to 50 nm.

9. The method for preparing a semiconductor device according to any one of claims 1 to 6, characterized in that: The material of the diamond heat dissipation layer includes at least one of single crystal diamond, polycrystalline diamond, amorphous diamond and diamond-metal composite material.

10. A semiconductor device, characterized in that: It comprises a diamond heat dissipation layer, a first metal bonding layer, a compound layer, a first metal bonding layer and a chip body which are stacked in sequence; the material of the compound layer comprises Ag2Cu3.

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