Method for manufacturing semiconductor device, and semiconductor device

Abstract

This method for manufacturing a semiconductor device comprises: a step for preparing a first substrate having a first support substrate, a first insulating film, and a first electrode provided in a first recess of the first insulating film; a step for preparing a second substrate having a second support substrate, a second insulating film, and a second electrode provided in a second recess of the second insulating film; a step for sticking together the first insulating film of the first substrate and the second insulating film of the second substrate; and a step for joining the first electrode of the first substrate and the second electrode of the second substrate. The first insulating film includes an organic insulating film. The first electrode includes a first electrode body provided in the first recess, a first barrier metal that is provided in at least one of the inner surface and the bottom surface of the first recess and that covers a part of the first electrode body, and a second barrier metal that covers the surface of the first electrode body at the opening side of the first recess. The adhesion strength between the first insulating film and the first barrier metal is 30 MPa or more.

Description

Semiconductor device manufacturing method and semiconductor device

[0001] The present disclosure relates to a method for manufacturing a semiconductor device and a semiconductor device.

[0002] In recent years, three-dimensional packaging has been considered to improve the integration density of LSIs. Patent Document 1 and Non-Patent Document 1 disclose examples of three-dimensional packaging of semiconductor chips.

[0003] US Patent Application Publication No. 2021 / 002815

[0004] FC Chen et al., “Systemon Integrated Chips(SoIC TM) for 3D Heterogeneous Integration”, 2019 IEEE 69th Electronic Components and Technology Conference (ECTC), p.594-599(2019)

[0005] When fabricating semiconductor devices using three-dimensional packaging, the use of hybrid bonding technology has been considered to facilitate miniaturization of wiring between devices. However, as shown in FIG. 7B, when hybrid bonding is performed, slight misalignment S may occur between the terminal electrodes (first electrode 113, second electrode 123). Such misalignment S may be caused, for example, by the miniaturization of the terminal electrodes themselves or by differences in thermal expansion coefficients due to heating during bonding. If such misalignment S occurs in a semiconductor device, copper or other materials constituting the terminal electrodes may dissolve into the resin constituting the insulating film (first insulating film 112, second insulating film 122), potentially causing migration at the interface between the copper or other electrode and the insulating film.

[0006] An object of the present disclosure is to provide a method for manufacturing a semiconductor device that can suppress migration at the interface between an electrode and an insulating film, and a semiconductor device.

[0007] [1] One aspect of the present disclosure relates to a method for manufacturing a semiconductor device. The method for manufacturing a semiconductor device includes the steps of: (a) preparing a first substrate including a first support substrate, a first insulating film provided on the first support substrate, and a first electrode provided in a first recess of the first insulating film and exposed from a first surface side of the first insulating film; (b) preparing a second substrate including a second support substrate, a second insulating film provided on the second support substrate, and a second electrode provided in a second recess of the second insulating film and exposed from a second surface side of the second insulating film; (c) bonding the first insulating film of the first substrate to the second insulating film of the second substrate; and (d) bonding the first electrode of the first substrate to the second electrode of the second substrate. The first insulating film includes an organic insulating film. The first electrode includes a first electrode body provided in the first recess, a first barrier metal provided on at least one of the inner surface and bottom surface of the first recess and covering a portion of the first electrode body, and a second barrier metal covering the surface of the first electrode body on the opening side of the first recess. The adhesive strength between the first insulating film and the first barrier metal is 30 MPa or more.

[0008] In this semiconductor device manufacturing method, the first electrode provided on the first insulating film includes a first barrier metal covering a portion of the first electrode body and a second barrier metal covering the surface of the first electrode body on the opening side of the first recess. In this case, the first barrier metal and the second barrier metal prevent elution of the first electrode body, which is often made of a material that easily dissolves, such as copper. This prevents migration at the interface between the first electrode and the first insulating film, even if misalignment occurs between the first electrode and the second electrode at any stage. Note that misalignment here includes even extremely small misalignments as long as they may cause migration. This also applies hereinafter. Furthermore, although the bond between electrode materials such as copper and the resin that constitutes the insulating film (organic insulating film) is weak and may result in peeling, providing the first barrier metal on at least one of the inner surface and bottom surface of the first recess in the first insulating film to cover a portion of the first electrode body and providing an adhesive strength of 30 MPa or more between the first insulating film and the first barrier metal prevents such peeling.

[0009] In this semiconductor device manufacturing method, the first insulating film includes an organic insulating film. In this case, the relatively soft organic material can absorb foreign matter (debris) adhering to the surface of the first substrate into the insulating film, thereby reducing poor connection between the first and second substrates. The organic insulating material included in the insulating film may be polyimide, a polyimide precursor, polyamideimide, benzocyclobutene (BCB), polybenzoxazole (PBO), or a PBO precursor. These materials are liquid or soluble in solvents, making it easy to fabricate the insulating film by, for example, spin coating, and to form thin films. Furthermore, these materials have high heat resistance, so they can withstand the high temperatures encountered when bonding the first and second substrates, enabling more reliable bonding between the first and second substrates. Note that a portion of the first insulating film may be formed from an inorganic insulating film, and the other portion (e.g., the surface side) may be formed from an organic insulating film.

[0010] [2] In the method for manufacturing a semiconductor device according to [1] above, it is further preferred that the adhesive strength between the first insulating film and the first barrier metal be 40 MPa or more. In this case, the first barrier metal can further suppress peeling between the electrode body made of copper or the like and the organic insulating film. The adhesive strength between the first insulating film and the first barrier metal may be 50 MPa or more.

[0011] [3] In the above-described method for manufacturing a semiconductor device, the step of a) preparing a first substrate may include the steps of: a1) forming a first insulating film on a first support substrate, a2) forming at least one first recess in the first insulating film, a3) forming a first barrier metal on inner and bottom surfaces of the first recess, a4) forming a first electrode body in a region within the first recess surrounded by the first barrier metal, and a5) forming a second barrier metal on a surface of the first electrode body. The step of b) preparing a second substrate may include the steps of: b1) forming a second insulating film on a second support substrate, b2) forming at least one second recess in the second insulating film, b3) forming a third barrier metal on inner and bottom surfaces of the second recess, b4) forming a second electrode body in a region within the second recess surrounded by the third barrier metal, and b5) forming a fourth barrier metal on a surface of the second electrode body.

[0012] [4] In the method for manufacturing a semiconductor device according to [3] above, in the step of forming the first barrier metal, the first barrier metal may be formed in the first recess of the first insulating film by electroless plating. In this case, it is possible to easily increase the adhesive strength between the first insulating film and the first barrier metal.

[0013] [5] In the method for manufacturing a semiconductor device according to [4], in the step of forming the first electrode body, the first electrode body may be formed by electrolytic plating using the first barrier metal as a power supply layer. In this case, the adhesive strength between the first barrier metal and the first electrode body can also be increased.

[0014] [6] In any of the semiconductor device manufacturing methods [3] to [5] above, in the step a4) of forming the first electrode body, a conductive material may be disposed on the first barrier metal and the first insulating film in the first recess so as to fill the first recess, and the disposed conductive material may be ground to form the first electrode body. Also, in the step b4) of forming the second electrode body, a conductive material may be disposed on the third barrier metal and the second insulating film in the second recess so as to fill the second recess, and the disposed conductive material may be ground to form the second electrode body.

[0015] [7] In the semiconductor device manufacturing method according to [6] above, the step a4) of forming the first electrode body may include grinding the conductive material and then polishing the first insulating film, and the step b4) of forming the second electrode body may include grinding the conductive material and then further polishing the second insulating film. The surface roughness of each of the polished first insulating film and second insulating film may be 0.1 μm or less. By ensuring that the surface roughness of each of the first insulating film and second insulating film is 0.1 μm or less, the bonding strength when the first insulating film and the second insulating film are bonded together can be increased. Note that the surface roughness used here is the arithmetic mean roughness Ra measured using a laser microscope at a magnification of 20x, and is the arithmetic mean roughness Ra specified in JIS B 0601 2001.

[0016] [8] In the method for manufacturing a semiconductor device according to [6] or [7] above, in the step a5) of forming a second barrier metal, the second barrier metal may be formed to cover the surface of the first electrode body after grinding the conductive material, and in the step b5) of forming a fourth barrier metal, the fourth barrier metal may be formed to cover the surface of the second electrode body after grinding the conductive material. In this case, the bonding strength between the first electrode body and the second barrier metal and the bonding strength between the second electrode body and the fourth barrier metal can be increased.

[0017] [9] In any of the semiconductor device manufacturing methods described in [3] to [8] above, the step of a) preparing a first substrate may include a step of modifying the surface of the first electrode body by at least one of ultraviolet irradiation, electron beam irradiation, ozone water treatment, corona discharge treatment, and plasma treatment before the step of forming the second barrier metal. In this case, the bonding strength of the second barrier metal to the first electrode body can be improved, and peeling of the second barrier metal can be suppressed, thereby suppressing migration. Note that in the step of b) preparing a second substrate, a similar treatment may be performed on the surface of the second electrode body.

[0018]

[10] In the method for manufacturing a semiconductor device according to any one of [1] to [9] above, it is preferable that the entire first electrode body is covered with the first barrier metal and the second barrier metal. In this case, migration at the interface between the first electrode and the first insulating film can be more reliably suppressed. It is also preferable that the entire second electrode body is covered with the third barrier metal and the fourth barrier metal. In this case, migration at the interface between the second electrode and the second insulating film can be more reliably suppressed.

[0019]

[11] In the method for manufacturing a semiconductor device according to any one of [1] to

[10] above, the thickness of the second barrier metal before bonding the first electrode and the second electrode may be 1 μm or less, and the thickness of the fourth barrier metal before bonding the first electrode and the second electrode may be 1 μm or less. In this case, miniaturization of the terminal electrode can be more reliably achieved.

[0020]

[12] In any of the semiconductor device manufacturing methods described above in [1] to

[11] , the second insulating film may include an organic insulating film, and the second electrode may include a second electrode body provided in the second recess, a third barrier metal provided on at least one of the inner surface and bottom surface of the second recess and covering a portion of the second electrode body, and a fourth barrier metal covering the surface of the second electrode body on the opening side of the second recess. In this manufacturing method, the adhesive strength between the second insulating film and the third barrier metal is preferably 30 MPa or more. In this case, the third barrier metal and the fourth barrier metal suppress elution of the second electrode body, which is often made of a material that easily elutes, such as copper. This makes it possible to suppress migration at the interface between the second electrode and the second insulating film, even if misalignment occurs between the first electrode and the second electrode at any stage. Furthermore, although the bond between electrode materials such as copper and the resin constituting the insulating film (organic insulating film) is weak and may result in peeling, such peeling can be suppressed by providing a third barrier metal on at least one of the inner surface and bottom surface of the second recess of the second insulating film to cover a portion of the second electrode body, and by ensuring that the adhesive strength between the second insulating film and the third barrier metal is 30 MPa or more. Incidentally, as in the case of the first insulating film described above, the second insulating film including an organic insulating film can absorb foreign matter and reduce connection defects. The adhesive strength between the second insulating film and the third barrier metal may be 40 MPa or more, or may be 50 MPa or more.

[0021]

[13] In the method for manufacturing a semiconductor device according to

[12] above, the first electrode may be formed so that the surface of the second barrier metal is recessed inward relative to the first surface of the first insulating film, and the second electrode may be formed so that the surface of the fourth barrier metal protrudes outward relative to the second surface of the second insulating film. In this case, in the step c) of bonding the first insulating film and the second insulating film, it is preferable that the protruding portion of the fourth barrier metal is fitted into the recessed region of the second barrier metal. Such a concave-convex configuration more reliably aligns the first substrate and the second substrate and prevents misalignment, thereby further suppressing migration at the interface between the electrode and the insulating film.

[0022]

[14] In the method for manufacturing a semiconductor device according to any one of [1] to

[13] above, at least one semiconductor element may be disposed in the first support substrate or on a surface of the first support substrate opposite to a surface on which the first insulating film is formed. Also, at least one semiconductor element may be disposed in the second support substrate or on a surface of the second support substrate opposite to a surface on which the second insulating film is formed.

[0023]

[15] In the semiconductor device manufacturing method according to any one of [1] to

[14] above, when bonding the first electrode and the second electrode, the second barrier metal and the fourth barrier metal may be bonded. In this case, even if misalignment occurs between the first electrode and the second electrode, a portion of at least one of the second barrier metal and the fourth barrier metal is bonded to the resin, thereby preventing the first electrode body and the second electrode body from being bonded to the resin. This more reliably suppresses migration at the interface between the first electrode and the first insulating film and the interface between the second electrode and the second insulating film.

[0024]

[16] In any of the semiconductor device manufacturing methods described above in [1] to

[15] , the second barrier metal and the fourth barrier metal preferably contain at least one selected from titanium, nickel, palladium, chromium, tantalum, tungsten, cobalt, and gold. More preferably, the second barrier metal and the fourth barrier metal contain at least one selected from nickel, cobalt, and tungsten. These materials have low ionization tendency and therefore high barrier performance. By including such a material with high barrier performance in the second barrier metal and the fourth barrier metal, migration at the interface between the first electrode and the first insulating film and the interface between the second electrode and the second insulating film can be more reliably suppressed.

[0025]

[17] In the method for manufacturing a semiconductor device according to any one of [1] to

[16] above, the first recess and the second recess preferably have an opening diameter or width of 5 μm to 50 μm. This method for manufacturing a semiconductor device can suppress migration even when a terminal electrode or a wiring electrode is formed in such a minute recess, making it possible to manufacture a semiconductor device having minute wiring.

[0026]

[18] In the method for manufacturing a semiconductor device according to any one of [1] to

[17] above, at least one of the first insulating film and the second insulating film may include a portion of an inorganic insulating film. When the insulating film includes an inorganic insulating film, recesses for forming terminal electrodes and the like can be easily miniaturized, making it possible to fabricate a semiconductor device with finer wiring. Furthermore, since inorganic materials are easily bonded to each other, the adhesive strength between the first substrate and the second substrate can be increased, thereby improving the connection reliability of the semiconductor device.

[0027]

[19] In the method for manufacturing a semiconductor device according to any one of the above [1] to

[18] , the second barrier metal and the fourth barrier metal may be formed by plating. In this case, thinner and finer barrier metals can be easily formed.

[0028]

[20] Another aspect of the present disclosure relates to a semiconductor device. The semiconductor device includes a first substrate and a second substrate. The first substrate includes a first support substrate, a first insulating film provided on the first support substrate, and a first electrode provided in a first recess of the first insulating film and exposed from a first surface side of the first insulating film. The second substrate includes a second support substrate, a second insulating film provided on the second support substrate, and a second electrode provided in a second recess of the second insulating film and exposed from a second surface side of the second insulating film. In this semiconductor device, the first insulating film includes an organic insulating film, the first insulating film and the second insulating film are bonded together, and the first electrode and the second electrode are joined together. The first electrode includes a first electrode body provided in the first recess, a first barrier metal provided on at least one of the inner surface and bottom surface of the first recess and covering a portion of the first electrode body, and a second barrier metal covering the surface of the first electrode body on the opening side of the first recess. The adhesive strength between the first insulating film and the first barrier metal is 30 MPa or more.

[0029] In this semiconductor device, the first electrode provided on the first insulating film includes a first barrier metal covering a portion of the first electrode body and a second barrier metal covering the surface of the first electrode body on the opening side of the first recess. In this case, the first barrier metal and the second barrier metal prevent elution of the first electrode body, which is often made of a material that easily dissolves, such as copper. This prevents migration at the interface between the first electrode and the first insulating film. Furthermore, although the bond between electrode materials such as copper and the resin constituting the insulating film (organic insulating film) is weak and can lead to peeling, providing the first barrier metal on at least one of the inner surface and bottom surface of the first recess in the first insulating film to cover a portion of the first electrode body and providing an adhesive strength of 30 MPa or greater between the first insulating film and the first barrier metal can prevent such peeling. The adhesive strength between the first insulating film and the first barrier metal may be 40 MPa or greater, or 50 MPa or greater.

[0030] In the semiconductor device described above, the second insulating film may include an organic insulating film, and the second electrode may include a second electrode body provided within the second recess, a third barrier metal provided on at least one of the inner surface and bottom surface of the second recess and covering a portion of the second electrode body, and a fourth barrier metal covering the surface of the second electrode body on the opening side of the second recess. The adhesive strength between the second insulating film and the third barrier metal is 30 MPa or more. In this case, the third barrier metal and the fourth barrier metal suppress elution of the second electrode body, which is often formed from a material that easily elutes, such as copper. This suppresses migration at the interface between the second electrode and the second insulating film. Furthermore, although the bond between electrode materials such as copper and the resin constituting the insulating film (organic insulating film) is weak and can lead to peeling, providing the third barrier metal on at least one of the inner surface and bottom surface of the second recess of the second insulating film to cover a portion of the second electrode body and having an adhesive strength of 30 MPa or more between the second insulating film and the third barrier metal can also suppress such peeling. The adhesive strength between the second insulating film and the third barrier metal may be 40 MPa or more, or 50 MPa or more.

[0031] According to the present disclosure, migration at the interface between the electrode and the insulating film can be suppressed.

[0032] FIG. 1 is a cross-sectional view showing an example of a semiconductor device manufactured by a method according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view showing an enlarged view of a bonding portion A of an electrode in the semiconductor device shown in FIG. 1 . FIG. 3 is a cross-sectional view for explaining a method of manufacturing the semiconductor device shown in FIG. 1 , showing an example of a process for manufacturing a first substrate and a second substrate. FIG. 4 is a cross-sectional view showing an enlarged view of region B shown in (d) of FIG. 3 . FIG. 5 is a cross-sectional view for explaining a method of manufacturing the semiconductor device shown in FIG. 1 , showing an example of a process for bonding the first substrate and the second substrate together, following the process of FIG. 3 . FIG. 6 is a cross-sectional view showing an example of a case where misalignment occurs in the process shown in FIG. 5 . FIG. 7(a) is a cross-sectional view showing a case where misalignment occurs at the bonding portion of a semiconductor device manufactured by a method according to an embodiment of the present disclosure, and FIG. 7(b) is a cross-sectional view showing a case where misalignment occurs at the bonding portion of a semiconductor device manufactured by a method according to a comparative example. FIG. 8 is a cross-sectional view for explaining a first modification of the method for manufacturing a semiconductor device according to the embodiment, where (a) is a cross-sectional view before bonding the electrodes, and (b) is a cross-sectional view after bonding the electrodes. 9A and 9B are cross-sectional views illustrating a second modified example of the method for manufacturing a semiconductor device according to this embodiment. FIG. 10 is a cross-sectional view illustrating a third modified example of the method for manufacturing a semiconductor device according to this embodiment.

[0033] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following description, identical or equivalent parts will be designated by the same reference numerals, and duplicate explanations will be omitted. Furthermore, unless otherwise specified, positional relationships such as up, down, left, and right will be based on the positional relationships shown in the drawings. Furthermore, the dimensional ratios of the drawings are not limited to those shown in the drawings.

[0034] In this specification, the term "layer" encompasses not only a structure with a shape formed over the entire surface when observed in a plan view, but also a structure with a shape formed on a portion of the surface. Furthermore, in this specification, the term "process" includes not only an independent process, but also a process that cannot be clearly distinguished from other processes, as long as the intended effect of the process is achieved. Furthermore, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively.

[0035] (Configuration of Semiconductor Device) FIG. 1 is a cross-sectional view showing an example of a semiconductor device manufactured by a method according to an embodiment of the present disclosure. FIG. 2 is an enlarged cross-sectional view showing a bonding portion A of an electrode in the semiconductor device shown in FIG. 1. The semiconductor device 1 is, for example, an example of a semiconductor package, and includes a first substrate 10 and a second substrate 20 as shown in FIGS. 1 and 2. In the semiconductor device 1, the first substrate 10 and the second substrate 20 are bonded together. The first substrate 10 may include a semiconductor chip 30 (semiconductor element), and the second substrate 20 may include a semiconductor chip 40 (semiconductor element). The semiconductor chip 30 may be disposed on the surface of the first substrate 10 opposite to the second substrate 20 (the bottom surface in FIG. 1). The semiconductor chip 40 may be disposed on the surface of the second substrate 20 opposite to the first substrate 10 (the top surface in FIG. 1). The semiconductor chips 30 and 40 are, for example, semiconductor chips such as LSI (Large Scale Integrated Circuit) chips, CMOS (Complementary Metal Oxide Semiconductor) sensors, and memories. The semiconductor chips 30 and 40 may be other types of semiconductor chips.

[0036] The first substrate 10 has a first support substrate 11, a first insulating film 12, and a plurality of first electrodes 13. The first insulating film 12 is provided on the first support substrate 11. Each of the first electrodes 13 is provided in a first recess 14 formed in the first insulating film 12, and is formed so as to be exposed from a first surface 12 a of the first insulating film 12.

[0037] The first support substrate 11 is not particularly limited, but may be, for example, a silicon plate, a glass plate, a SUS plate, a substrate containing glass cloth, or a semiconductor element-containing sealing resin. The first support substrate 11 is preferably a substrate made of high rigidity. The thickness of the first support substrate 11 is preferably, for example, in the range of 0.2 mm to 2.0 mm. A thickness of 0.2 mm or more improves the handleability of the first support substrate 11. Furthermore, a thickness of 2.0 mm or less enables reduction in material costs and enables the semiconductor device 1 to be made thinner. The shape of the first support substrate 11 in a planar view may be either a wafer shape (disk shape) or a panel shape (rectangular shape). The size of the first support substrate 11 is not particularly limited, but may be, for example, a wafer shape with a diameter of 200 mm, 300 mm, or 450 mm, or a rectangular panel with a side length of 300 mm to 700 mm. The semiconductor chip 30 may be provided on the inside of the first support substrate 11 or on the surface of the first support substrate 11 opposite to the second substrate 20 (the lower surface in FIG. 1).

[0038] The first insulating film 12 is made of an organic insulating material. The first insulating film 12 may partially contain an inorganic insulating material. The organic insulating material forming the first insulating film 12 is, for example, a photosensitive organic insulating material or a thermosetting organic insulating material. The inorganic insulating material forming the first insulating film 12 is, for example, silicon nitride (SiN), silicon dioxide (SiO ２), or a silicon-containing material such as silicon oxynitride (SiON). More specifically, the organic insulating material forming the first insulating film 12 may be, for example, polyimide, a polyimide precursor, polyamideimide, benzocyclobutene (BCB), polybenzoxazole (PBO), or a PBO precursor. These materials are liquid or soluble in a solvent, making it easy to prepare an insulating film by, for example, spin coating, and to form a thin film. Furthermore, these materials have high heat resistance, so they can withstand the high temperatures encountered when bonding the first substrate 10 and the second substrate 20, enabling more reliable bonding between the first substrate 10 and the second substrate 20. The organic insulating material forming the first insulating film 12 may be a liquid or film-like material, with a film-like material being preferred from the standpoints of film thickness flatness and cost. The first insulating film 12 may contain a filler in the organic insulating material, and the average particle size of the filler contained in the insulating material is preferably 500 nm or less. The inclusion of such a filler makes it possible to easily form a fine trench structure in the first insulating film 12. Note that the first insulating film 12 does not necessarily need to contain a filler. The particle size of the filler can be measured by a laser diffraction particle size distribution measurement method.

[0039] When forming the first insulating film 12 by laminating a film-like organic insulating material onto the first support substrate 11, lamination is preferably performed in a low-temperature process, and therefore the first insulating film 12 is preferably a photosensitive organic insulating film that can be laminated at 40°C to 120°C. By allowing the photosensitive insulating film used for the first insulating film 12 to be laminated at a temperature of 40°C or higher, tackiness at room temperature can be reduced, making handling easier. By allowing the photosensitive insulating film used for the first insulating film 12 to be laminated at a temperature of 120°C or lower, warping of the photosensitive insulating film after lamination can be reduced. The thermal expansion coefficient of the organic insulating material used for the first insulating film 12 after curing is preferably 80 ppm / °C or less from the viewpoint of suppressing warpage, and more preferably 70 ppm / °C or less from the viewpoint of achieving high reliability. The thermal expansion coefficient of the insulating material used for the first insulating film 12 after curing is preferably 20 ppm / °C or more from the viewpoints of stress relaxation and obtaining high-resolution patterns.

[0040] The thickness of the first insulating film 12 is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less. By setting the thickness of the first insulating film 12 to such a thickness, the first recess 14 formed in the first insulating film 12 can be made finer. From the viewpoint of ensuring electrical reliability, the thickness of the first insulating film 12 is preferably 1 μm or more.

[0041] The first electrode 13 is an electrode formed in the first insulating film 12 and includes a first electrode body 13a, a first barrier metal 13b, and a second barrier metal 13c. The first electrode 13 may be a terminal electrode such as a bump, or may be a wiring electrode. The first electrode body 13a is provided in a first recess 14 formed in the first insulating film 12 and is formed of a highly conductive material such as copper, aluminum, or silver. The first barrier metal 13b is provided on the inner surface 14a and bottom surface 14b of the first recess 14 and covers the side and bottom surfaces of the first electrode body 13a. The thickness of the first barrier metal 13b is, for example, in the range of 0.1 μm to 0.8 μm. The adhesive strength between the first insulating film 12 and the first barrier metal 13b is 30 MPa or more. The adhesive strength between the first insulating film 12 and the first barrier metal 13b is preferably 40 MPa or more, and more preferably 50 MPa or more. The second barrier metal 13c covers the surface of the first electrode body 13a on the opening side of the first recess 14. The thickness of the second barrier metal 13c is, for example, in the range of 0.1 μm to 0.8 μm, and is 1 μm or less before being bonded to the second electrode. The first electrode body 13a is entirely covered with the first barrier metal 13b and the second barrier metal 13c.

[0042] The first barrier metal 13b and the second barrier metal 13c are portions for preventing the first electrode body 13a, which is made of a material that easily ionsize, from eluting into the resin, and are made of a conductive material with low ionization tendency. The first barrier metal 13b and the second barrier metal 13c are preferably made of a plating film (e.g., an electroless plating film), such as a nickel plating film, a palladium plating film, a cobalt plating film, a gold plating film, or an alloy plating film containing at least one of nickel, palladium, cobalt, and gold. From the viewpoint of improving adhesive strength with the first insulating film 12, the first barrier metal 13b is preferably made of a titanium film, a nickel film, a chromium film, a tungsten film, or a cobalt film. From the viewpoints of adhesion to the first electrode body 13a and temperature cycle resistance, the first barrier metal 13b and the second barrier metal 13c are preferably nickel-plated films or palladium-plated films. These materials have low ionization tendency and high barrier performance for preventing elution of materials such as copper constituting the first electrode body 13a. From the viewpoint of barrier performance, the first barrier metal 13b and the second barrier metal 13c are preferably composed of at least one selected from nickel, cobalt, and tungsten.

[0043] The second substrate 20 includes a second support substrate 21, a second insulating film 22, and a plurality of second electrodes 23. The second insulating film 22 is provided on the second support substrate 21. Each second electrode 23 is provided in a second recess 24 formed in the second insulating film 22 and is exposed from a second surface 22a of the second insulating film 22. The second substrate 20 may have a configuration similar to that of the first substrate 10. The configuration of the second support substrate 21 may be similar to that of the first support substrate 11. The configuration of the second insulating film 22 may be similar to that of the first insulating film 12, and the second insulating film 22 may be formed from an organic insulating material. The second insulating film 22 may partially contain an inorganic insulating material. Because the configuration of the second substrate 20 corresponds to that of the first substrate 10, a description of the configurations of the second support substrate 21 and the second insulating film 22 will be omitted.

[0044] The second electrode 23 has a configuration similar to that of the first electrode 13 and includes a second electrode body 23a, a third barrier metal 23b, and a fourth barrier metal 23c. The second electrode 23 is an electrode bonded to the first electrode 13 and, like the first electrode 13, may be a terminal electrode such as a bump or a wiring electrode. The second electrode body 23a is provided in a second recess 24 formed in the second insulating film 22 and is made of a highly conductive material such as copper, aluminum, or silver. The third barrier metal 23b is provided on the inner surface 24a and bottom surface 24b of the second recess 24 and covers the side and bottom surfaces of the second electrode body 23a. The thickness of the third barrier metal 23b is, for example, in the range of 0.1 μm to 0.8 μm. The adhesive strength between the second insulating film 22 and the third barrier metal 23b is 30 MPa or more. The adhesive strength between the second insulating film 22 and the third barrier metal 23b is preferably 40 MPa or more, and more preferably 50 MPa or more. The fourth barrier metal 23c covers the surface of the second electrode body 23a on the opening side of the second recess 24. The thickness of the fourth barrier metal 23c is, for example, in the range of 0.1 μm to 0.8 μm, and is 1 μm or less before being bonded to the first electrode 13. The second electrode body 23a is entirely covered with the third barrier metal 23b and the fourth barrier metal 23c.

[0045] The third barrier metal 23b and the fourth barrier metal 23c are portions for preventing the second electrode body 23a, which is made of a material that easily ionsize, from eluting into the resin. Similar to the first barrier metal 13b and the second barrier metal 13c, the third barrier metal 23b and the fourth barrier metal 23c are made of a conductive material with low ionization tendency. The third barrier metal 23b and the fourth barrier metal 23c are preferably made of a plating film (e.g., an electroless plating film), such as a nickel plating film, a palladium plating film, a cobalt plating film, a gold plating film, or an alloy plating film containing at least one of nickel, palladium, cobalt, and gold. From the viewpoint of improving adhesive strength with the second insulating film 22, the third barrier metal 23b is preferably made of a titanium film, a nickel film, a chromium film, a tungsten film, or a cobalt film. Furthermore, from the viewpoints of adhesion to the second electrode body 23a and temperature cycle resistance, the third barrier metal 23b and the fourth barrier metal 23c are preferably nickel-plated films or palladium-plated films. Furthermore, these materials have low ionization tendency and high barrier performance for preventing the elution of materials such as copper constituting the second electrode body 23a. From the viewpoint of barrier performance, the third barrier metal 23b and the fourth barrier metal 23c are preferably composed of at least one selected from nickel, cobalt, and tungsten. In the semiconductor device 1, the second barrier metal 13c of the first electrode 13 and the fourth barrier metal 23c of the second electrode 23 are bonded together.

[0046] (Method of Manufacturing Semiconductor Device) Next, a method of manufacturing the semiconductor device 1 will be described with reference to FIGS. 3 to 5. FIG. 3 is a cross-sectional view for explaining the method of manufacturing the semiconductor device 1, and shows an example of the steps of manufacturing each of the first substrate 10 and the second substrate 20. FIG. 4 is a cross-sectional view showing an enlarged view of region B shown in FIG. 3(d). FIG. 5 is a cross-sectional view for explaining the method of manufacturing the semiconductor device 1, and shows an example of the step of bonding the first substrate 10 and the second substrate 20 together, following the step of FIG. 3.

[0047] The semiconductor device 1 can be manufactured, for example, through the following steps (a) to (d): a) preparing a first substrate having a first support substrate, a first insulating film provided on the first support substrate, and a first electrode provided in a first recess in the first insulating film and exposed from a first surface side of the first insulating film; b) preparing a second substrate having a second support substrate, a second insulating film provided on the second support substrate, and a second electrode provided in a second recess in the second insulating film and exposed from a second surface side of the second insulating film; c) bonding the first insulating film of the first substrate and the second insulating film of the second substrate together; and d) joining the first electrode of the first substrate and the second electrode of the second substrate together.

[0048] The above-mentioned a) step of preparing a first substrate includes the following steps: a1) step of forming a first insulating film on a first support substrate, a2) step of forming at least one first recess in the first insulating film, a3) step of forming a first barrier metal on the inner surface and bottom surface of the first recess, a4) step of forming a first electrode body in a region within the first recess surrounded by the first barrier metal, and a5) step of forming a second barrier metal on the surface of the first electrode body. Also, b) step of preparing a second substrate includes the following steps: b1) step of forming a second insulating film on a second support substrate, b2) step of forming at least one second recess in the second insulating film, b3) step of forming a third barrier metal on the inner surface and bottom surface of the second recess, b4) step of forming a second electrode body in a region within the second recess surrounded by the third barrier metal, and b5) step of forming a fourth barrier metal on the surface of the second electrode body.

[0049] [Step (a)] A method for fabricating (preparing) the first substrate 10 will be described. To fabricate the first substrate 10, first, a first support substrate 11 is prepared. The first support substrate 11 is, for example, a substrate with a thickness of 0.2 mm to 2.0 mm and is a wafer-shaped or panel-shaped substrate. The first support substrate 11 may have other configurations. Then, as shown in FIG. 3A, a first insulating film 12 is formed on the first support substrate 11. For example, if the first insulating film 12 is formed from a photosensitive insulating film, the first insulating film 12 is formed by laminating the photosensitive insulating film on the first support substrate 11. The insulating film material and the like described above can be used. The lamination temperature may be, for example, 40°C to 120°C. The photosensitive insulating film used here may contain a thermosetting organic insulating material. Note that the method for forming the first insulating film 12 is not limited to this, and other methods may also be used. For example, when the first insulating film 12 is formed from a liquid organic insulating material, the first insulating film 12 may be formed by applying the insulating material onto the first support substrate 11 and then rotating the first support substrate 11, for example. The thickness of the first insulating film 12 formed on the first support substrate 11 is, for example, 10 μm or less, preferably 5 μm or less, and more preferably 3 μm or less. The thickness of the first insulating film 12 may also be 1 μm or more. The first insulating film 12 may also be formed from an inorganic material.

[0050] Next, as shown in FIG. 3B, multiple first recesses 14 are formed in the first insulating film 12. The first recesses 14 can be formed using, for example, laser ablation, photolithography, imprinting, or the like. Using a photolithography process allows for the production of fine first recesses 14 at low cost. When forming recesses using a photolithography process, it is preferable to use a film-like photosensitive organic insulating material for the first insulating film 12. Typical exposure methods for photosensitive organic insulating materials include projection exposure, contact exposure, and direct writing exposure. Development methods include developing using an alkaline aqueous solution of sodium carbonate or TMAH. After forming the first recesses 14, the insulating material (thermosetting material) constituting the first insulating film 12 may be further heated and cured. The heating temperature in this case may be, for example, 100°C to 200°C, and the heating time may be, for example, 30 minutes to 3 hours. The first recesses 14 formed by the above method have an opening diameter or width of 5 μm to 50 μm.

[0051] Next, after the first recesses 14 are formed in the first insulating film 12, a first barrier metal 13b is formed on the inner surface 14a and the bottom surface 14b of each of the first recesses 14. In the step of forming the first barrier metal 13b, as shown in FIG. 3B, a conductive material 3A constituting the first barrier metal 13b is formed on the inner surface 14a and the bottom surface 14b of each of the first recesses 14 and the first surface 12a of the first insulating film 12 by plating (electroless plating) or the like. At this time, the first barrier metal is formed so that the adhesive strength between the first insulating film 12 and the first barrier metal 13b is 30 MPa or more. The adhesive strength between the first insulating film 12 and the first barrier metal 13b may be 40 MPa or more, or may be 50 MPa or more. The conductive material 3A constituting the first barrier metal 13b includes, for example, at least one selected from titanium, nickel, palladium, chromium, tantalum, tungsten, cobalt, and gold. The first barrier metal 13b also functions as a seed layer for forming the first electrode body 13a (described later), and may be made of any one of titanium, copper, nickel, nickel alloys (NiP, NiB, CoNiP), cobalt, and tungsten alloys (Taw). These materials are applied by, for example, electroless plating.

[0052] Here, we will explain the adhesive strength when a barrier film is applied to an organic material film. If copper is applied directly to an organic material film without a barrier film, the copper oxidizes over time and peels off from the organic material film. However, if a copper electrode is applied to the organic material film via a barrier film, such peeling is prevented. For example, the present inventors used a photosensitive insulating material (manufactured by Resonac Corporation, product name AH-3000) as the organic material film and a NiB film (manufactured by JCU Corporation, product name) as the barrier film, and formed the barrier film on this organic material film by electroless nickel boron plating. The formed barrier film had a thickness of 100 nm. The barrier film was formed using electroless plating. A peel strength test between the barrier film and the organic material film was performed on this test piece. The peel strength was, for example, 40 MPa. This confirms that the above-described method can achieve an adhesive strength of 30 MPa or more between the first insulating film 12 and the first barrier metal 13b. By changing the type of organic insulating film or the type of barrier film used, it is possible to further increase the bonding strength between the first insulating film 12 and the first barrier metal 13b to 50 MPa or more. The above-mentioned can also be applied to the bonding strength between the second insulating film 22 and the third barrier metal 23b, which will be described later.

[0053] Subsequently, after the first barrier metal 13b (conductive material 3A) is formed, the first electrode body 13a is formed in the region surrounded by the first barrier metal 13b within the first recess 14. In the process of forming the first electrode body 13a, as shown in FIG. 3C, a conductive material 3B constituting the first electrode body 13a is formed by electroplating or the like on the conductive material 3A formed in the first recess 14 and on the first insulating film 12. The conductive material 3B forming the first electrode body 13a includes, for example, at least one selected from copper, aluminum, and silver. The first electrode body 13a (conductive material 3B) is formed by electroplating using the first barrier metal 13b (conductive material 3A) functioning as a seed layer as a power supply layer. When forming the first electrode body 13a, a conductive material such as copper is deposited on the first barrier metal 13b in the first recess 14 and on the first insulating film 12 so as to fill the first recess 14.

[0054] Subsequently, after the conductive material 3B that forms the first electrode body 13a is formed, the conductive material 3A of the first barrier metal 13b and the conductive material 3B of the first electrode body 13a are ground to remove unnecessary portions, thereby forming the first barrier metal 13b and the first electrode body 13a to a predetermined thickness. Note that during this grinding, the first insulating film 12 may also be ground together with the conductive material 3A and the conductive material 3B to form the predetermined thickness.

[0055] Subsequently, after the first electrode body 13 a and the first barrier metal 13 b are formed, the first surface 12 a of the first insulating film 12 is polished. For this polishing, a grinder for electronic materials processing or a method such as CMP (Chemical Mechanical Polishing) can be used. By this polishing, the surface roughness of the first surface 12 a of the first insulating film 12 becomes 0.1 μm or less. The surface roughness used here is the arithmetic mean roughness Ra measured using a laser microscope at a magnification of 20 times, and is the arithmetic mean roughness Ra specified in JIS B 0601 2001. During this polishing, the polishing may be performed under conditions such that the surface of the first electrode body 13a and the first surface 12a of the first insulating film 12 are flush with each other, such that the surface of the first electrode body 13a protrudes from the first surface 12a of the first insulating film 12, or such that the surface of the first electrode body 13a is recessed inward from the first surface 12a of the first insulating film 12. As an example, the first insulating film 12 is polished so that the surface of the first electrode body 13a is slightly recessed inward from the first surface 12a of the first insulating film 12. Note that these conditions can be controlled by appropriately adjusting the polishing liquid used in CMP, the polishing conditions, and the like.

[0056] After the surfaces of the first insulating film 12 and the first electrode body 13a are polished, the surface of the first electrode body 13a is subjected to surface modification by at least one of ultraviolet irradiation, electron beam irradiation, ozone water treatment, corona discharge treatment, and plasma treatment. This surface modification is a pretreatment for forming the second barrier metal 13c described later.

[0057] Next, as shown in FIG. 3D, a second barrier metal 13c is formed on the surface of the first electrode body 13a. In this process, after the above-described processes of polishing the conductive material and pretreating the surface of the first electrode body, the second barrier metal is formed to cover the surface of the first electrode body 13a. The second barrier metal 13c is formed on the first electrode body 13a by, for example, electroless plating. This second barrier metal 13c is formed from a material containing at least one selected from titanium, nickel, palladium, chromium, tantalum, tungsten, cobalt, and gold. The second barrier metal 13c is formed from a material with low ionization tendency. Note that when the second barrier metal 13c is formed by electroless plating, a material may be formed to cover the first surface 12a of the first insulating film 12, as in the formation of the first barrier metal 13b. In this case, excess material is ground or polished in the same manner as described above. Through the above processes, the first substrate 10 is prepared.

[0058] [Step (b)] The method for producing the second substrate 20 is similar to the method for producing the first substrate 10, and therefore detailed description will be omitted. However, the second substrate 20 is produced through the above-described steps shown in Fig. 3. In the examples shown in Fig. 3 and Fig. 5, the second substrate 20 has the same configuration as the first substrate 10, but it does not need to have exactly the same configuration as the first substrate 10. The thickness or material of the second support substrate 21, the thickness or material of the second insulating film 22, the presence or absence of a semiconductor chip, etc. may be different from those of the first substrate 10.

[0059] [Step (c)] Next, after preparation of the first substrate 10 and the second substrate 20 is completed, the first insulating film 12 of the first substrate 10 and the second insulating film 22 of the second substrate 20 are bonded together. In this step, as shown in (a) of Fig. 5, at least one of the first substrate 10 and the second substrate 20 is aligned so that the first electrode 13 of the first substrate 10 and the second electrode 23 of the second substrate 20 correspond to each other. Both the first substrate 10 and the second substrate 20 may be aligned. For such alignment, an alignment mark or the like may be provided on at least one of the first substrate 10 and the second substrate 20.

[0060] In step (c), organic matter or metal oxide adhering to the surfaces of the first substrate 10 and the second substrate 20 is removed, and then the second substrate 20 is aligned with respect to the first substrate 10. After the alignment is complete, the first insulating film 12 of the first substrate 10 and the second insulating film 22 of the second substrate 20 are bonded to each other using hybrid bonding. At this time, the first insulating film 12 of the first substrate 10 and the second insulating film 22 of the second substrate 20 may be uniformly heated before bonding. The temperature difference between the first substrate 10 and the second substrate 20 during bonding is preferably, for example, 10°C or less. By performing heat bonding at such a uniform temperature, the first insulating film 12 is mechanically and firmly attached to the second insulating film 22. Furthermore, since heat bonding is performed at a uniform temperature, misalignment at the bonding site is unlikely to occur, enabling high-precision bonding. During the bonding stage, the first electrode 13 of the first substrate 10 and the second electrode 23 of the second substrate 20 are spaced apart from each other and are not bonded (although they are aligned). The first substrate 10 and the second substrate 20 may be bonded together by other bonding methods, such as room temperature bonding.

[0061] [Step (d)] Next, after the first substrate 10 and the second substrate 20 are bonded together, the plurality of first electrodes 13 of the first substrate 10 and the plurality of second electrodes 23 of the second substrate 20 are bonded together. In step (d), as shown in FIG. 5B , after the bonding in step (c) is completed, a predetermined amount of heat and / or pressure is applied to bond the first electrodes 13 of the first substrate 10 and the second electrodes 23 of the second substrate 20 by hybrid bonding. When the first electrodes 13 and the second electrodes 23 are made of, for example, copper, the annealing temperature in step (d) is preferably 150° C. or higher and 400° C. or lower, and more preferably 200° C. or higher and 300° C. or lower. This bonding process forms an electrode bonded portion where the first electrodes 13 and the corresponding second electrodes 23 are bonded together, and the first electrodes 13 and the second electrodes 23 are firmly bonded together mechanically and electrically. The electrode bonding in step (d) may be performed after the lamination in step (c), or may be performed simultaneously with the lamination in step (c).

[0062] Through the above steps, the semiconductor device 1 shown in FIG. 1 is fabricated.

[0063] Here, with reference to FIGS. 6 and 7 , the effects of the semiconductor device manufacturing method according to this embodiment will be described in comparison with the semiconductor device manufacturing method according to a comparative example. FIG. 6 is a cross-sectional view showing an example in which misalignment occurs when bonding the first electrode 13 and the second electrode 23 together after bonding the first substrate 10 and the second substrate 20. FIG. 7A is a cross-sectional view showing a case in which misalignment occurs at the bonding points of a semiconductor device 1A manufactured by the method according to this embodiment, and FIG. 7B is a cross-sectional view showing a case in which misalignment occurs at the bonding points of a semiconductor device manufactured by the method according to the comparative example. The manufacturing method according to the comparative example differs from the manufacturing method according to this embodiment in that metal caps corresponding to the second barrier metal 13c and the fourth barrier metal 23c are not provided on the first electrode 113 corresponding to the first electrode 13 and the second electrode 123 corresponding to the second electrode 23. Other steps and configurations are the same as those of the embodiment.

[0064] 7B, in the manufacturing method of the semiconductor device according to the comparative example, when such misalignment occurs, the first electrode body 113a of the first electrode 113 is exposed to the resin that constitutes the second insulating layer 121 due to misalignment S. Similarly, the second electrode body 123a of the second electrode 123 is exposed to the resin that constitutes the first insulating layer 111. In this case, copper and other materials that constitute the first electrode body 113a and the second electrode body 123a are eluted, causing migration between the electrodes and the resin. This can result in, for example, a short circuit between the terminal electrodes.

[0065] In contrast, in the semiconductor device 1, 1A and the manufacturing method thereof according to this embodiment, the surface of the first electrode body 13a of the first electrode 13 is covered with the second barrier metal 13c, and the entire first electrode body 13a is covered with the first barrier metal 13b and the second barrier metal 13c. Similarly, the surface of the second electrode body 23a of the second electrode 23 is covered with the fourth barrier metal 23c, and the entire second electrode body 23a is covered with the third barrier metal 23b and the fourth barrier metal 23c. In this case, the elution of the first electrode body 13a and the second electrode body 23a, which are often made of a material that is easily eluted, such as copper, is suppressed by the first barrier metal 13b, the second barrier metal 13c, the third barrier metal 23b, and the fourth barrier metal 23c. As a result, even if a positional misalignment occurs between the first electrode 13 and the second electrode 23 at any stage, migration at the interface between the first electrode 13 and the first insulating film 12 can be suppressed, and migration at the interface between the second electrode 23 and the second insulating film 22 can also be suppressed.

[0066] Furthermore, the bond between the electrode material, such as copper, and the resin constituting the insulating film is weak and may result in peeling. However, in the manufacturing method of the semiconductor device 1, 1A according to this embodiment, the first barrier metal 13b is provided on the inner surface 14a and bottom surface 14b of the first recess 14 of the first insulating film 12 to cover a portion of the first electrode body 13a, and the adhesive strength between the first insulating film 12 and the first barrier metal 13b is 30 MPa or more, thereby preventing such peeling. Similarly, the third barrier metal 23b is provided on the inner surface 24a and bottom surface 24b of the second recess 24 of the second insulating film 22 to cover a portion of the second electrode body 23a, and the adhesive strength between the second insulating film 22 and the third barrier metal 23b is 30 MPa or more, thereby preventing such peeling.

[0067] Furthermore, in the manufacturing method of the semiconductor device 1, 1A according to this embodiment, the first insulating film 12 and the second insulating film 22 include an organic insulating film. In this case, the relatively soft organic material absorbs foreign matter (debris) adhering to the surfaces of the first substrate 10 and the second substrate 20 into the insulating film, thereby reducing poor connection between the first substrate 10 and the second substrate 20. The organic insulating material contained in the insulating film may be polyimide, a polyimide precursor, polyamideimide, benzocyclobutene (BCB), polybenzoxazole (PBO), or a PBO precursor. These materials are liquid or soluble in a solvent, making it easy to prepare the insulating film by, for example, spin coating, and to form a thin film. Furthermore, these materials have high heat resistance, so they can withstand the high temperatures that are encountered when bonding the first substrate 10 and the second substrate 20, enabling more reliable bonding between the first substrate 10 and the second substrate 20.

[0068] Furthermore, in the manufacturing method of the semiconductor device 1, 1A according to this embodiment, the thickness of the second barrier metal 13c and the fourth barrier metal 23c may be 1 μm or less before bonding the first electrode 13 and the second electrode 23. In this case, miniaturization of the terminal electrodes can be more reliably achieved.

[0069] Furthermore, in the manufacturing method of the semiconductor device 1, 1A according to this embodiment, when the first electrode 13 and the second electrode 23 are bonded, the second barrier metal 13c and the fourth barrier metal 23c are also bonded. As a result, even if misalignment occurs between the first electrode 13 and the second electrode 23, a portion of at least one of the second barrier metal 13c and the fourth barrier metal 23c is bonded to the resin, preventing the first electrode body 13a and the second electrode body 23a from being bonded to the resin. This makes it possible to more reliably suppress migration at the interface between the first electrode 13 and the first insulating film 12 and the interface between the second electrode 23 and the second insulating film 22.

[0070] In the manufacturing method of the semiconductor device 1, 1A according to this embodiment, the second barrier metal 13c and the fourth barrier metal 23c may be formed to contain at least one selected from titanium, nickel, palladium, chromium, tantalum, tungsten, cobalt, and gold. When the second barrier metal 13c and the fourth barrier metal 23c contain such a material with high barrier performance, migration at the interface between the first electrode 13 and the first insulating film 12 and the interface between the second electrode 23 and the second insulating film 22 can be more reliably suppressed.

[0071] In the above-described manufacturing method, the first insulating film 12 and the second insulating film 22 include an organic insulating film. However, this is not limited thereto. In the manufacturing method of a semiconductor device according to this embodiment, the first insulating film 12 and the second insulating film 22 may further include an inorganic insulating film. When the insulating film includes an inorganic insulating film, recesses for terminal electrodes can be easily miniaturized, making it possible to manufacture semiconductor devices 1, 1A with finer wiring. Furthermore, since inorganic materials are easily bonded to each other, the adhesive strength between the first substrate 10 and the second substrate 20 can be increased, thereby improving the connection reliability of the semiconductor device.

[0072] Furthermore, in the manufacturing method of the semiconductor device 1, 1A according to this embodiment, the first insulating film 12 and the second insulating film 22 may be polished by CMP or the like, and the surface roughness of each of the polished first insulating film 12 and second insulating film 22 may be 0.1 μm or less, thereby increasing the bonding strength when the first insulating film 12 and the second insulating film 22 are bonded together.

[0073] In the manufacturing method of the semiconductor device 1, 1A according to this embodiment, before the step of forming the second barrier metal 13c, the surface of the first electrode body 13a may be surface-modified by at least one of ultraviolet irradiation, electron beam irradiation, ozone water treatment, corona discharge treatment, and plasma treatment. This can improve the bonding strength of the second barrier metal 13c to the first electrode body 13a, suppress peeling of the second barrier metal 13c, and suppress migration. Similarly, before the step of forming the fourth barrier metal 23c, the surface of the second electrode body 23a may be surface-modified by at least one of ultraviolet irradiation, electron beam irradiation, ozone water treatment, corona discharge treatment, and plasma treatment. This can improve the bonding strength of the fourth barrier metal 23c to the second electrode body 23a, suppress peeling of the fourth barrier metal 23c, and suppress migration.

[0074] [First Modification] Here, a first modification of the semiconductor device manufacturing method according to this embodiment will be described with reference to FIG. 8 . FIG. 8 is a cross-sectional view illustrating the first modification of the semiconductor device manufacturing method according to this embodiment. As shown in FIG. 8A, in step (a) of the semiconductor device manufacturing method according to this first modification, the first electrode 13A is formed such that the surface of the second barrier metal 13c is recessed inward relative to the first surface 12a of the first insulating film 12. Formation of such a recessed region 13d can be achieved by controlling at least one of the following: the depth of the first recess 14, the thickness of the first barrier metal 13b, the amount of conductive material constituting the first electrode body 13a or the position of the surface of the first electrode body 13a, the grinding or polishing conditions for the first insulating film 12 and the first electrode body 13a, and the thickness or amount of the second barrier metal 13c to be disposed.

[0075] Furthermore, in the manufacturing method of a semiconductor device according to the first modification, in step (b), the second electrode 23A is formed such that the surface of the fourth barrier metal 23c protrudes outward beyond the second surface 22a of the second insulating film 22. Such protruding portion 23d can be formed by controlling at least one of the depth of the second recess 24, the thickness of the third barrier metal 23b, the amount of conductive material constituting the second electrode body 23a or the position of the surface of the second electrode body 23a, the conditions for grinding or polishing the second insulating film 22 and the second electrode body 23a, and the thickness or amount of the fourth barrier metal 23c to be disposed.

[0076] 8B, in the manufacturing method according to the first modification, when the first insulating film 12 and the second insulating film 22 are bonded together in step (c), the protruding portion 23d of the fourth barrier metal 23c is fitted into the recessed region 13d of the second barrier metal 13c. This uneven structure ensures that the first substrate 10 and the second substrate 20 are aligned more reliably and prevents misalignment. Then, in step (d), the first electrode 13A and the second electrode 23A are bonded together. In the manufacturing method according to the first modification, in addition to the effect of preventing copper elution by the second barrier metal 13c and the fourth barrier metal 23c, the alignment structure prevents misalignment during bonding. This further suppresses migration at the interface between the electrodes and the insulating film.

[0077] [Second Modification] Next, a second modification of the semiconductor device manufacturing method according to this embodiment will be described with reference to FIG. 9 . FIG. 9 is a cross-sectional view illustrating the second modification of the semiconductor device manufacturing method according to this embodiment. In the above-described embodiment, the first electrode 13 and the second electrode 23 have the same width. However, this is not limiting. For example, as shown in FIG. 9 , the first electrode 13B may be formed so that its width is wider than the second electrode 23. In this case, even if the second electrode 23 is slightly misaligned with respect to the first electrode 13B, the entire second electrode 23 can be bonded to the first electrode 13B. The width of the first electrode 13B may be, for example, more than 1.0 times but not more than 3.0 times the width of the second electrode 23. In this case, migration at the interface between the electrode and the insulating film can be suppressed even if a slight misalignment occurs.

[0078] [Third Modification] Next, a third modification of the semiconductor device manufacturing method according to this embodiment will be described with reference to FIG. 10 . FIG. 10 is a cross-sectional view illustrating the third modification of the semiconductor device manufacturing method according to this embodiment. In the third modification, as in the second modification, the width of the first electrode 13B is wider than the width of the second electrode 23C, as shown in FIG. 10 . Meanwhile, in this modification, the first electrode 13B includes the second barrier metal 13c, but the second electrode 23C does not include the fourth barrier metal 23c. In this case, even if the second electrode 23C is slightly misaligned with respect to the first electrode 13B, the entire second electrode 23C can be bonded to the first electrode 13B. Therefore, even if there is some misalignment, migration at the interface between the electrode and the insulating film can be suppressed. By providing a barrier metal, which is a metal cap, on at least one side, migration can be suppressed.

[0079] Although the embodiments of the present disclosure have been described above, the present invention is not limited to the above-described embodiments, and appropriate modifications may be made without departing from the spirit of the present disclosure.

[0080] 1, 1A...semiconductor device, 10...first substrate, 11...first support substrate, 12...first insulating film, 12a...first surface, 13, 13A, 13B...first electrode, 13a...first electrode body, 13b...first barrier metal, 13c...second barrier metal, 13d...recessed region, 14...first recess, 14a...inner surface, 14b...bottom surface, 20...second substrate, 21...second support substrate, 22...second insulating film, 22a...second surface, 23, 23A, 23C...second electrode, 23a...second electrode body, 23b...third barrier metal, 23c...fourth barrier metal, 23d...protruding portion, 30, 40...semiconductor chip (semiconductor element).

Claims

1. preparing a first substrate including a first support substrate, a first insulating film provided on the first support substrate, and a first electrode provided in a first recess of the first insulating film and exposed from a first surface side of the first insulating film; preparing a second substrate including a second support substrate, a second insulating film provided on the second support substrate, and a second electrode provided in a second recess of the second insulating film and exposed from a second surface side of the second insulating film; bonding the first insulating film of the first substrate and the second insulating film of the second substrate; and joining the first electrode of the first substrate and the second electrode of the second substrate, the first insulating film includes an organic insulating film, the first electrode includes a first electrode body provided in the first recess, a first barrier metal provided on at least one of an inner surface and a bottom surface of the first recess and covering a part of the first electrode body, and a second barrier metal covering a surface of the first electrode body on the opening side of the first recess, The method for manufacturing a semiconductor device, wherein the adhesive strength between the organic insulating film and the first barrier metal of the first insulating film is 30 MPa or more.

2. the adhesive strength between the organic insulating film and the first barrier metal of the first insulating film is 40 MPa or more; The method for manufacturing a semiconductor device according to claim 1 .

3. The step of preparing the first substrate includes: forming the first insulating film on the first support substrate; forming at least one first recess in the first insulating film; forming the first barrier metal on the inner surface and the bottom surface of the first recess; forming the first electrode body in a region surrounded by the first barrier metal in the first recess; and forming a second barrier metal on the surface of the first electrode body. The method for manufacturing a semiconductor device according to claim 1 .

4. The organic insulating film of the first insulating film is formed from a photosensitive organic insulating material or a thermosetting organic insulating material. The method for manufacturing a semiconductor device according to claim 1 .

5. The organic insulating film of the first insulating film is formed from an organic insulating material containing a filler. The method for manufacturing a semiconductor device according to claim 1 .

6. The first insulating film is formed from a photosensitive organic insulating film that can be laminated at 40°C to 120°C. The method for manufacturing a semiconductor device according to claim 1 .

7. In the step of forming the first electrode body, a conductive material is disposed on the first barrier metal and the first insulating film in the first recess so as to fill at least the first recess, and the disposed conductive material is ground to form the first electrode body. The method for manufacturing a semiconductor device according to claim 3 .

8. In the step of forming the first electrode body, the conductive material is ground and then the first insulating film is polished, and the surface roughness of the polished first insulating film is 0.1 μm or less. The method for manufacturing a semiconductor device according to claim 7 .

9. The step of preparing the first substrate includes a step of modifying the surface of the first electrode body by at least one of ultraviolet irradiation, electron beam irradiation, ozone water treatment, corona discharge treatment, and plasma treatment before the step of forming the second barrier metal. The method for manufacturing a semiconductor device according to claim 3 .

10. the first electrode body is entirely covered with the first barrier metal and the second barrier metal; The method for manufacturing a semiconductor device according to claim 1 .

11. The second insulating film includes an organic insulating film, In the step of bonding the first insulating film and the second insulating film, the organic insulating film of the first insulating film and the organic insulating film of the second insulating film are bonded to each other. The method for manufacturing a semiconductor device according to any one of claims 1 to 10.

12. the second insulating film includes an organic insulating film, the second electrode includes a second electrode body provided in the second recess, a third barrier metal provided on at least one of an inner surface and a bottom surface of the second recess and covering a part of the second electrode body, and a fourth barrier metal covering a surface of the second electrode body on the opening side of the second recess, the adhesive strength between the organic insulating film of the second insulating film and the third barrier metal is 30 MPa or more; The method for manufacturing a semiconductor device according to any one of claims 1 to 10.

13. the first electrode is formed such that a surface of the second barrier metal is recessed inward from the first surface of the first insulating film; the second electrode is formed such that a surface of the fourth barrier metal protrudes outward beyond the second surface of the second insulating film; In the step of bonding the first insulating film and the second insulating film, a protruding portion of the fourth barrier metal is fitted into a recessed region of the second barrier metal. The method for manufacturing a semiconductor device according to claim 12.

14. At least one semiconductor element is disposed in the first support substrate or on a surface of the first support substrate opposite to a surface on which the first insulating film is formed. The method for manufacturing a semiconductor device according to any one of claims 1 to 10.

15. a first substrate including a first support substrate, a first insulating film provided on the first support substrate, and a first electrode provided in a first recess of the first insulating film and exposed from a first surface side of the first insulating film; a second substrate including a second support substrate, a second insulating film provided on the second support substrate, and a second electrode provided in a second recess of the second insulating film and exposed from a second surface side of the second insulating film; the first insulating film includes an organic insulating film, the first insulating film and the second insulating film are bonded together, the first electrode and the second electrode are joined together, the first electrode includes a first electrode body provided in the first recess, a first barrier metal provided on at least one of an inner surface and a bottom surface of the first recess and covering a part of the first electrode body, and a second barrier metal covering a surface of the first electrode body on the opening side of the first recess, The semiconductor device, wherein the adhesive strength between the organic insulating film and the first barrier metal of the first insulating film is 30 MPa or more.

16. the second insulating film includes an organic insulating film, the second electrode includes a second electrode body provided in the second recess, a third barrier metal provided on at least one of an inner surface and a bottom surface of the second recess and covering a part of the second electrode body, and a fourth barrier metal covering a surface of the second electrode body on the opening side of the second recess, the adhesive strength between the organic insulating film of the second insulating film and the third barrier metal is 30 MPa or more; The semiconductor device according to claim 15.