JP5982748B2 - SEMICONDUCTOR DEVICE, SEMICONDUCTOR DEVICE MANUFACTURING METHOD, AND ELECTRONIC DEVICE - Google Patents

Description

The present technology relates to a semiconductor device , a method for manufacturing a semiconductor device , and an electronic device , and more particularly, a semiconductor device in which interelectrode bonding is performed by bonding two substrates, a method for manufacturing such a semiconductor device , and The present invention relates to an electronic device using the semiconductor device .

  As one of the structures for achieving further high integration of semiconductor devices, a three-dimensional structure in which two substrates each having an element and wiring formed thereon are stacked and bonded has been proposed. When manufacturing a semiconductor device having such a three-dimensional structure, first, two substrates each having an element formed thereon are prepared, and bonding electrodes (bonding pads) are provided on the bonding surface side of each substrate. Pulled out. At this time, for example, by applying an embedded wiring technique (so-called damascene processing), a bonding surface having a configuration in which an electrode for bonding made of copper (Cu) is surrounded by an insulating film is formed. Thereafter, the two substrates are arranged with the bonding surfaces facing each other, and the two substrates are laminated by causing the electrodes provided on each bonding surface to correspond to each other, and heat treatment is performed in this state. Thereby, the substrates having the electrodes joined together are bonded together (for example, see Patent Document 1 below).

  Here, the electrode is formed by a general embedded wiring technique, for example, as follows. First, a groove pattern is formed in an insulating film covering the surface of the substrate, and then a conductive base layer (barrier metal layer) having a barrier property against copper (Cu) is covered with the insulating film while covering the inner wall of the groove pattern. A film is formed on top. Next, after an electrode film using copper (Cu) is formed on the barrier metal layer with the groove pattern embedded, the electrode film is polished until the barrier metal layer is exposed, and the insulating film is exposed. Polish the barrier metal layer and electrode film. Thereby, a buried electrode is formed in which the electrode film is buried in the groove pattern formed in the insulating film via the barrier metal layer.

  In the above embedded wiring technology, the polishing of the electrode film can be automatically stopped when the electrode film is polished and the barrier metal layer is exposed, but in the subsequent polishing of the electrode film and the barrier metal layer, The polishing of the electrode film cannot be stopped automatically when the insulating film is exposed. Therefore, in the polished surface, dishing in which the electrode film in the groove pattern is excessively polished and erosion in which the electrode film in the groove pattern is excessively polished depending on the electrode layout are likely to occur and are flat. It is difficult to obtain a polished surface. Therefore, before the electrode film is formed, a method is proposed in which the barrier metal layer on the insulating film is removed, leaving the barrier metal layer only on the inner wall of the groove pattern, and the electrode film is formed on the upper portion and polished. (See Patent Document 2 below).

JP 2006-191081 A JP 2000-12540 A

  By the way, in the semiconductor device having a three-dimensional structure obtained by bonding as described above, the bonding strength between two substrates and the bonding strength between the electrodes are prevented while preventing the diffusion of the electrode material into the insulating film. A secured structure is desired. However, the semiconductor device manufacturing method disclosed in Patent Document 1 cannot prevent the electrode material from diffusing into the insulating film.

  On the other hand, in the embedded wiring technique disclosed in Patent Document 2, diffusion of the electrode material into the insulating film can be prevented by providing the electrode film via the barrier metal layer (underlying layer). However, this embedded wiring technique does not consider bonding between substrates, and the barrier metal layer is exposed together with the electrode and the insulating film on the planarized surface obtained by polishing. For this reason, it is difficult to ensure sufficient bonding strength over the entire planarized surface.

  Therefore, in the present technology, the bonding strength is ensured while preventing the diffusion of the electrode material into the insulating film in the configuration in which the electrodes are bonded by bonding the two substrates, thereby improving the reliability. An object of the present invention is to provide a semiconductor device having the three-dimensional structure shown. It is another object of the present technology to provide a method for manufacturing such a semiconductor device.

  In order to achieve the above object, a semiconductor device of the present technology includes a first substrate and a second substrate provided to be bonded to the first substrate. In particular, the first substrate includes a first electrode and a first insulating film that is made of a diffusion preventing material for the first electrode and covers the periphery of the first electrode. The first substrate has a bonding surface composed of the first electrode and the first insulating film. On the other hand, the second substrate includes a second electrode bonded to the first electrode and a second insulating film that is made of a diffusion preventing material for the second electrode and covers the periphery of the second electrode. In addition, the second substrate is configured such that the second electrode and the second insulating film constitute a bonding surface for the first substrate.

  According to the present technology as described above, since the periphery of the electrode is covered with the insulating film made of a diffusion preventing material for the electrode, it is not necessary to provide a barrier metal layer between the insulating film and the electrode. For this reason, the bonding surface of the two substrates (the first substrate and the second substrate) is composed only of the insulating film and the electrode to ensure the bonding strength, and prevent the electrode material from diffusing into the insulating film. be able to.

  Furthermore, the present technology is also a manufacturing method of the semiconductor device of the present technology described above, and includes the following procedure. First, an insulating film made of a diffusion preventing material for the electrode material is formed on the substrate, and a groove pattern is formed in the insulating film. Next, an electrode film made of an electrode material is formed on the insulating film in a state where the groove pattern formed in the insulating film is embedded. Further, the electrode film is polished until the insulating film is exposed, and an electrode in which the electrode film is embedded in the groove pattern is patterned. Thereafter, the two substrates on which the electrodes are formed as described above are bonded together in a state where the electrodes are joined together.

  As described above, according to the present technology, in the configuration in which the electrodes are bonded by bonding the two substrates, the bonding strength is ensured while preventing the diffusion of the electrode material, thereby improving the reliability. Thus, it is possible to obtain a semiconductor device having a three-dimensional structure.

It is a schematic structure figure showing an example of a semiconductor device to which this art is applied. It is principal part sectional drawing which shows the structure of the semiconductor device of embodiment. It is sectional process drawing which shows the manufacture procedure (the 1) of the sensor substrate in manufacture of the semiconductor device of embodiment. It is sectional process drawing which shows the manufacture procedure (the 2) of the sensor substrate in manufacture of the semiconductor device of embodiment. It is a cross-sectional process drawing which shows the manufacturing procedure (the 1) of the circuit board in manufacture of the semiconductor device of embodiment. It is sectional process drawing which shows the preparation procedure (the 2) of the circuit board in manufacture of the semiconductor device of embodiment. It is sectional drawing (the 1) which shows bonding in manufacture of the semiconductor device of embodiment. It is sectional drawing (the 2) which shows bonding in manufacture of the semiconductor device of embodiment. It is principal part sectional drawing which shows an example of the manufacturing method of the semiconductor device used as the comparison of this technique. It is principal part sectional drawing which shows the structure of the semiconductor device used as the modification of this technique. It is a block diagram of the electronic device using the semiconductor device obtained by applying this technique.

Hereinafter, embodiments of the present technology will be described in the following order based on the drawings.
1. 1. Example of schematic configuration of semiconductor device of embodiment 2. Configuration of Semiconductor Device of Embodiment 3. Production procedure of sensor substrate in production of semiconductor device of embodiment 4. Manufacturing procedure of circuit board in manufacturing of semiconductor device of embodiment 5. Bonding of substrates in manufacture of semiconductor device of embodiment Modification Example of Semiconductor Device of Embodiment 7 Example of electronic apparatus using semiconductor device of embodiment

<< 1. Example of schematic configuration of semiconductor device of embodiment >>
FIG. 1 shows a schematic configuration of a solid-state imaging device as an example of a three-dimensional structure semiconductor device to which the present technology is applied. A semiconductor device 1 shown in this figure includes a sensor substrate 2 as a first substrate and a circuit substrate 7 as a second substrate, and is attached as a second substrate laminated to the sensor substrate 2. This is a so-called three-dimensional structure semiconductor device (solid-state imaging device). Hereinafter, the sensor substrate 2 as the first substrate is simply referred to as the sensor substrate 2, and the circuit substrate 7 as the second substrate is simply referred to as the circuit substrate 7.

  On one surface side of the sensor substrate 2, a pixel region 4 in which a plurality of pixels 3 including a photoelectric conversion unit are regularly arranged in a two-dimensional manner is provided. In the pixel region 4, a plurality of pixel drive lines 5 are wired in the row direction, and a plurality of vertical signal lines 6 are wired in the column direction. One pixel 3 has one pixel drive line 5 and one line. It is arranged in a state of being connected to the vertical signal line 6. Each of these pixels 3 is provided with a photoelectric conversion unit, a charge storage unit, and a pixel circuit composed of a plurality of transistors (so-called MOS transistors) and a capacitor element. In some cases, a plurality of pixels share a part of the pixel circuit.

  On one surface side of the circuit board 7, peripheral circuits such as a vertical drive circuit 8, a column signal processing circuit 9, a horizontal drive circuit 10, and a system control circuit 11 for driving each pixel 3 provided on the sensor board 2. Is provided.

≪2. Configuration of Semiconductor Device of Embodiment >>
FIG. 2 is a cross-sectional view of a main part showing the configuration of the semiconductor device of the embodiment, and is a cross-sectional view of three pixels in FIG. Hereinafter, a detailed configuration of the semiconductor device of the embodiment will be described based on the cross-sectional view of the main part.

  The semiconductor device 1 shown in FIG. 2 is a solid-state imaging device having a three-dimensional structure in which the sensor substrate 2 and the circuit substrate 7 are bonded together as described above. The sensor substrate 2 includes a semiconductor layer 2a, and a wiring layer 2b and an electrode layer 2c disposed on the surface of the semiconductor layer 2a on the circuit board 7 side. The circuit board 7 includes a semiconductor layer 7a, and a first wiring layer 7b, a second wiring layer 7c, and an electrode layer 7d arranged on the surface of the semiconductor layer 7a on the sensor substrate 2 side.

  The sensor substrate 2 and the circuit substrate 7 as described above are bonded together with the surface of the electrode layer 2c and the surface of the electrode layer 7d as a bonding surface. In the present embodiment, as will be described later in detail. The structures of the electrode layer 2c and the electrode layer 7d are characteristic.

  A protective film 15, a color filter layer 17, and an on-chip lens 19 are laminated in this order on the surface of the sensor substrate 2 opposite to the circuit board 7.

  Next, detailed configurations of the respective layers constituting the sensor substrate 2 and the circuit substrate 7 will be sequentially described, and further, the configurations of the protective film 15, the color filter layer 17, and the on-chip lens 19 will be sequentially described.

[Semiconductor layer 2a (sensor substrate 2 side)]
The semiconductor layer 2a on the sensor substrate 2 side is obtained by thinning a semiconductor substrate made of, for example, single crystal silicon. In the semiconductor layer 2a, on the first surface side where the color filter layer 17, the on-chip lens 19 and the like are arranged, a photoelectric conversion unit 21 made of, for example, an n-type impurity layer (or a p-type impurity layer) is provided for each pixel. Is provided. On the second surface side of the semiconductor layer 2a, there are provided a floating diffusion FD composed of an n + type impurity layer, a source / drain 23 of the transistor Tr, and other impurity layers not shown here. .

[Wiring layer 2b (sensor substrate 2 side)]
The wiring layer 2b provided on the semiconductor layer 2a in the sensor substrate 2 is provided on the interface side with the semiconductor layer 2a via the gate insulating film 25, the transfer gate TG and the gate electrode 27 of the transistor Tr. The other electrodes which are not shown in FIG. The transfer gate TG and the gate electrode 27 are covered with an interlayer insulating film 29, and a buried wiring 31 using, for example, copper (Cu) is provided in a groove pattern provided in the interlayer insulating film 29. It has been.

  In this case, the interlayer insulating film 29 is configured using, for example, silicon oxide. Further, when the layout of the embedded wiring 31 is dense, it may be configured using a material having a dielectric constant lower than that of silicon oxide in order to reduce the capacitance between the embedded wirings 31. In such an interlayer insulating film 29, a groove pattern that opens to the circuit board 7 side is formed, and a part of the groove pattern reaches the transfer gate TG and the gate electrode 27.

  In such a groove pattern, a wiring layer 31b made of copper (Cu) is provided via a barrier metal layer 31a, and the embedded wiring 31 is constituted by these two layers. Here, the barrier metal layer 31a is a layer for preventing the diffusion of copper (Cu) into the interlayer insulating film 29 made of silicon oxide or a material having a lower dielectric constant than this, for example, tantalum (Ta) or tantalum nitride ( TaN).

  The wiring layer 2b as described above may be configured as a multilayer wiring layer that is further laminated.

[Electrode layer 2c (sensor substrate 2 side)]
The electrode layer 2c on the sensor substrate 2 side provided on the wiring layer 2b is a first insulating layer that covers the periphery of the first electrode 33 and the first electrode 33 drawn to the surface on the circuit substrate 7 side in the sensor substrate 2. And a film 35. The first electrode 33 and the first insulating film 35 constitute a bonding surface 41 for the circuit board 7 in the sensor substrate 2.

  Among these, the 1st electrode 33 is comprised by the single material layer, for example, is comprised using copper (Cu). Such a first electrode 33 is configured as an embedded wiring embedded in the first insulating film 35.

  The first insulating film 35 is provided so as to cover the wiring layer 2b. The first insulating film 35 includes a groove pattern 35a opening on the circuit board 7 side, and the first electrode 33 is embedded in the groove pattern 35a. That is, the first insulating film 35 is provided in contact with the periphery of the first electrode 33. Although illustration is omitted here, a part of the groove pattern 35a provided in the first insulating film 35 reaches the embedded wiring 31 provided in the wiring layer 2b, and the first embedded in this inside. One electrode 33 is connected to the embedded wiring 31 as necessary.

  The first insulating film 35 as described above is made of a diffusion preventing material for the material constituting the first electrode 35. As such a diffusion preventing material, a material having a small diffusion coefficient with respect to the material constituting the first electrode 35 is used. In particular, in the present embodiment, the first insulating film 35 is configured as a single material layer using a diffusion preventing material. In the present embodiment, the first insulating film 35 is a diffusion preventing material for the first electrode 33 and also prevents diffusion for the material constituting the second electrode 67 drawn to the surface of the circuit board 7 on the sensor substrate 2 side. Consists of materials.

  For example, when the first electrode 33 and the second electrode 67 are made of copper (Cu), the diffusion preventing material constituting the first insulating film 35 is an inorganic material having a molecular structure denser than that of silicon oxide. An insulating material or an organic insulating material is used. Examples of such an inorganic insulating material include silicon nitride (SiN), silicon carbonitride (SiCN), silicon oxynitride (SiON), and silicon carbide (SiC). Examples of the organic insulating material include benzocyclobutene (BCB), polybenzoxazole (PBO), polyimide, and polyallyl ether (PAE). Since the electrode layer 2c is the uppermost layer on the sensor substrate 2 side, the layout of the first electrode 33 is also rough. For this reason, it is difficult to attach a capacitance between the first electrodes 33 and a low dielectric constant is not required for the first insulating film 35.

  As described above, the surface of the sensor substrate 2 on the side of the circuit board 7 is configured as the bonding surface 41 with the circuit board 7 and is configured by only the first electrode 33 and the first insulating film 35. . This bonding surface 41 is configured as a flattened surface.

[Semiconductor layer 7a (circuit board 7 side)]
The semiconductor layer 7a on the circuit board 7 side is formed by thinning a semiconductor substrate made of, for example, single crystal silicon. In the semiconductor layer 7a, the source / drain 51 of the transistor Tr, an impurity layer not shown here, and the like are provided on the surface layer on the sensor substrate 2 side.

[First wiring layer 7b (circuit board 7 side)]
The first wiring layer 7b on the circuit board 7 side has a gate electrode 55 provided via a gate insulating film 53 on the interface side with the semiconductor layer 7a, and other electrodes not shown here. ing. These gate electrodes 55 and other electrodes are covered with an interlayer insulating film 57, and a buried wiring 59 using, for example, copper (Cu) is provided in a groove pattern provided in the interlayer insulating film 57. ing.

  The configurations of the interlayer insulating film 57 and the embedded wiring 59 are the same as those of the wiring layer 2b on the sensor substrate 2 side. That is, in the interlayer insulating film 57, a groove pattern that opens to the sensor substrate 2 side is formed, and a part of the groove pattern reaches the gate electrode 55 and the source / drain 51. Further, in such a groove pattern, a wiring layer 59b made of copper (Cu) is provided via a barrier metal layer 59a, and the embedded wiring 59 is constituted by these two layers.

[Second wiring layer 7c (circuit board 7 side)]
The second wiring layer 7c on the circuit board 7 side includes an interlayer insulating film 63 laminated via a diffusion preventing insulating film 61 on the interface side with the first wiring layer 7b. An embedded wiring 65 using, for example, copper (Cu) is provided in the groove pattern provided in the diffusion preventing insulating film 61 and the interlayer insulating film 63.

  The diffusion prevention insulating film 61 is made of a diffusion prevention material for the material constituting the embedded wiring 59 provided in the first wiring layer 7b. Such a diffusion preventing insulating film 61 is made of, for example, silicon nitride (SiN), silicon carbonitride (SiCN), silicon oxynitride (SiON), or silicon carbide (SiC).

  The configuration of the interlayer insulating film 63 and the embedded wiring 65 is the same as that of the wiring layer 2b on the sensor substrate 2 side. That is, the interlayer insulating film 63 is formed with a groove pattern that opens to the sensor substrate 2 side, and a part of the groove pattern reaches the embedded wiring 59 of the first wiring layer 7b. Further, in such a groove pattern, a wiring layer 65b made of copper (Cu) is provided through a barrier metal layer 65a, and the embedded wiring 65 is constituted by these two layers.

  The first wiring layer 7b and the second wiring layer 7c as described above may be configured as a multilayer wiring layer that is further laminated.

[Electrode layer 7d (circuit board 7 side)]
The electrode layer 7d on the circuit board 7 side, which is the second substrate, is formed on the circuit board 7 with the second electrode 67 drawn to the surface on the sensor board 2 side and joined to the first electrode 33, and the periphery of the second electrode 67. And a second insulating film 69 covering the substrate. The second electrode 67 and the second insulating film 69 constitute a bonding surface 71 for the sensor substrate 2 in the circuit substrate 7, and are configured in the same manner as the electrode layer 2c on the sensor substrate 2 side as described below. Has been.

  That is, the second electrode 67 is composed of a single material layer, and is composed of a material that maintains good bonding properties with the first electrode 33 provided on the sensor substrate 2 side. For this reason, the second electrode 67 may be made of the same material as the first electrode 33, and is made of, for example, copper (Cu). Such a second electrode 67 is configured as an embedded wiring embedded in the second insulating film 69.

  The second insulating film 69 is provided so as to cover the second wiring layer 7c, and includes a groove pattern 69a that opens to the sensor substrate 2, and the second electrode 67 is embedded in the groove pattern 69a. . That is, the second insulating film 69 is provided in contact with the periphery of the second electrode 67. Although illustration is omitted here, a part of the groove pattern 69a provided in the second insulating film 69 reaches the buried wiring 65 in the lower layer, and the second electrode 67 buried therein is formed. It is in a state of being connected to the embedded wiring 65 as necessary.

  The second insulating film 69 as described above is made of a diffusion preventing material for the material constituting the second electrode 67. In particular, in the present embodiment, the second insulating film 69 is configured as a single material layer using a diffusion preventing material. In the present embodiment, the second insulating film 69 is made of a diffusion preventing material for the material constituting the first electrode 33 drawn to the bonding surface of the sensor substrate 2 with the circuit board 7 together with the second electrode 67. It is good.

  The second insulating film 69 can be made of a material selected from the materials exemplified as the first insulating film 35 provided on the sensor substrate 2 side. The second insulating film 69 is made of a material that maintains good bonding properties with the first insulating film 35 on the sensor substrate 2 side. For this reason, the second insulating film 69 may be made of the same material as the first insulating film 35. Further, since the electrode layer 7d is the uppermost layer on the circuit board 7 side, the layout of the second electrode 67 is also rough. For this reason, it is difficult to attach a capacitance between the second electrodes 67, and a low dielectric constant is not required for the second insulating film 69.

  As described above, the surface on the sensor substrate 2 side of the circuit board 7 is configured as the bonding surface 71 with the sensor-side substrate 2 and is configured by only the second electrode 67 and the second insulating film 69. Yes. The bonding surface 71 is configured as a flattened surface.

[Protective film 15]
The protective film 15 covering the photoelectric conversion portion 21 of the sensor substrate 2 is formed of a material film having passivation properties, and for example, a silicon oxide film, a silicon nitride film, or a silicon oxynitride film is used.

[Color filter layer 17]
The color filter layer 17 is composed of color filters of respective colors provided in a ratio of 1: 1 corresponding to the photoelectric conversion units 21. The arrangement of the color filters for each color is not limited.

[On-chip lens 19]
The on-chip lens 19 is provided in a ratio of 1: 1 corresponding to each color filter constituting each photoelectric conversion unit 21 and the color filter layer 17, and is configured so that incident light is condensed on each photoelectric conversion unit 21. Has been.

[Operation and Effect of Semiconductor Device of Embodiment]
According to the semiconductor device 1 configured as described above, the first electrode 33 has a structure in which the first electrode 33 is covered with the first insulating film 35 made of a diffusion preventing material for the first electrode 33. There is no need to provide a barrier metal layer between the first insulating film 35 and the first insulating film 35. Similarly, since the second electrode 67 is covered with a second insulating film 69 made of a diffusion preventing material for the second electrode 67, a barrier is provided between the second electrode 67 and the second insulating film 69. There is no need to provide a metal layer.

  For this reason, each of the bonding surface 41 of the sensor substrate 2 and the bonding surface 71 of the circuit board 7 is composed of only the insulating films 35 and 69 and the electrodes 33 and 67 to ensure the bonding strength, while ensuring the bonding strength. , 67 can be prevented from diffusing into the insulating films 35, 69.

  As a result, in the semiconductor device 1 having a three-dimensional structure in which the electrodes 33 and 67 are bonded to each other by bonding the sensor substrate 2 and the circuit substrate 7, while preventing diffusion of the electrode material into the insulating films 35 and 69. The bonding strength is ensured and the reliability can be improved.

≪3. Manufacturing Procedure of Sensor Substrate in Manufacturing Semiconductor Device of Embodiment >>
FIG. 3 is a cross-sectional process diagram (part 1) for explaining a manufacturing procedure of a sensor substrate used for manufacturing the semiconductor device having the configuration described in the embodiment, and FIG. 4 is a cross-sectional process diagram (part 2). Hereinafter, a procedure for producing a sensor substrate used in the embodiment will be described with reference to these drawings.

[FIG. 3A]
First, as shown in FIG. 3A, a semiconductor substrate 20 made of, for example, single crystal silicon is prepared. A photoelectric conversion portion 21 made of an n-type impurity layer is formed at a predetermined depth of the semiconductor substrate 20, and a positive charge transfer portion made of an n + -type impurity layer and a positive electrode made of a p + -type impurity layer are further formed on the surface layer of the photoelectric conversion portion 21. A hole charge storage portion is formed. Further, on the surface layer of the semiconductor substrate 20, a floating diffusion FD composed of an n + -type impurity layer, a source / drain 23, and other impurity layers not shown here are formed.

  Further, a gate insulating film 25 is formed on the surface of the semiconductor substrate 20, and a transfer gate TG and a gate electrode 27 are further formed thereon. The transfer gate TG is formed between the floating version FD and the photoelectric conversion unit 21, and the gate electrode 27 is formed between the source / drain 23. In the same process, another electrode not shown here is formed.

  Thereafter, an interlayer insulating film 29 made of, for example, silicon oxide is formed on the semiconductor substrate 20 so as to cover the transfer gate TG and the gate electrode 27.

[FIG. 3B]
Next, as shown in FIG. 3B, a groove pattern 29 a is formed in the interlayer insulating film 29. The groove pattern 29a is formed in a shape that reaches the transfer gate TG at a location as necessary. Although not shown here, a groove pattern reaching the source / drain 23 is formed in the interlayer insulating film 29 and the gate insulating film 25 at necessary portions.

  Next, a barrier metal layer 31a is formed in a state of covering the inner wall of the groove pattern 29a, and a wiring layer 31b made of copper (Cu) is formed in a state of embedding the groove pattern 29a in the upper portion.

[FIG. 3C]
Thereafter, as shown in FIG. 3C, the wiring layer 31b is planarized and removed by a chemical mechanical polishing (CMP) method until the barrier metal layer 31a is exposed, and further until the interlayer insulating film 29 is exposed. The barrier metal layer 31a is planarized and removed. Thereby, the embedded wiring 31 is formed by embedding the wiring layer 31b in the groove pattern 29a via the barrier metal layer 31a, and the wiring layer 2b including the embedded wiring 31 is obtained.

  The steps described above are not particularly limited in the process procedure, and may be performed according to an appropriately selected normal process procedure. In the present technology, the following steps are characteristic steps.

[FIG. 4A]
That is, first, as shown in FIG. 4A, a first insulating film 35 is formed on the wiring layer 2b. The first insulating film 35 is formed using a diffusion preventing material for the material constituting the first electrode film to be formed next. For example, when the first electrode film is made of copper (Cu), the first insulating film 35 is made of an inorganic insulating material or an organic insulating material having a molecular structure denser than that of silicon oxide. Examples of such an inorganic insulating material include silicon nitride (SiN), silicon carbonitride (SiCN), silicon oxynitride (SiON), and silicon carbide (SiC). Examples of the organic insulating material include benzocyclobutene (BCB), polybenzoxazole (PBO), polyimide, and polyallyl ether (PAE).

  The first insulating film 35 made of each material as described above is formed by a film formation method suitable for each material. For example, chemical vapor deposition (CVD) is applied to inorganic insulating materials, and CVD and coating methods are applied to organic insulating materials.

  Next, a groove pattern 35 a is formed in the first insulating film 35. The groove pattern 35a has a shape in which the electrode pad is embedded, and reaches the embedded wiring 31 in the lower layer at a necessary portion (not shown).

  Such a groove pattern 35a is formed as follows. For example, if the first insulating film 35 is made of an inorganic insulating material, first, a resist pattern is formed on the first insulating film 35 by photolithography, and the first insulating film 35 is etched using this as a mask. Thereby, the groove pattern 35a is formed. On the other hand, if the first insulating film 35 is made of an organic insulating material, an inorganic material layer is first formed on the first insulating film 35, and a resist pattern is formed thereon. Next, the inorganic material layer is etched using the resist pattern as a mask to form an inorganic mask, and then the first insulating film 35 is etched from above the inorganic mask. Thus, the groove pattern 35a is formed. After the groove pattern 35a is formed, the inorganic mask is removed from the first insulating film 35.

[FIG. 4B]
Next, as shown in FIG. 4B, the first electrode film 33a is directly formed on the first insulating film 35 in a state where the groove pattern 35a is embedded. The first electrode film 33a is made of a material that is prevented from diffusing into the first insulating film 35, and is made of, for example, copper (Cu). The first electrode film 33a is formed by, for example, a plating method using a seed layer as an electrode after forming a thin seed layer by sputtering.

[FIG. 4C]
Next, as shown in FIG. 4C, the first electrode film 33a directly formed on the first insulating film 35 is planarized and removed by CMP until the first insulating film 35 is exposed. At this time, the first insulating film 35 is used as a polishing stopper, and CMP is performed so that polishing automatically stops in order from the first electrode film 33a portion where the first insulating film 35 is exposed in the periphery of the polishing surface. For such CMP, the first electrode film 33a may be a chemically active material typified by copper (Cu), and the following various methods are exemplified.

  For example, in a portion where the first insulating film 35 is exposed to the periphery due to the progress of polishing by CMP of the first electrode film 33a, the local temperature change of the polishing slurry and the local occupation ratio of the first insulating film 33a on the polishing surface Changes occur. Therefore, there is a method of automatically stopping the progress of polishing by CMP locally in the portion of the first electrode film 33a where the first insulating film 35 is exposed by a chemical action utilizing these local changes. Illustrated.

  Further, there is exemplified a method in which only the surface of the electrode film 33a is denatured and the polishing is advanced only at the portion in contact with the polishing pad without using the chemical etching action. In this case, in the portion of the first electrode film 33a where the first insulating film 35 is exposed to the periphery by the progress of polishing of the first electrode film 33a by CMP, the surface of the first insulating film 35 becomes the reference surface, and polishing further proceeds. There is nothing. For this reason, the polishing is automatically stopped in order from the first electrode film 33 portion where the first insulating film 35 is exposed to the periphery. Specifically, such CMP is performed by using an abrasive-less Cu polishing slurry “HS-C430” (trade name, manufactured by Hitachi Chemical Co., Ltd.) as the polishing slurry.

  As described above, the first electrode 33 formed by embedding the first electrode film 33a in the groove pattern 35a is formed as an embedded electrode, and the electrode layer 2c including the first electrode 33 is obtained. Thereby, the sensor substrate 2 having the flat bonding surface 41 composed of the first electrode 33 and the first insulating film 35 is manufactured as the first substrate.

<< 4. Circuit Board Manufacturing Procedure in Manufacturing Semiconductor Device of Embodiment >>
FIG. 5 is a cross-sectional process diagram (part 1) for explaining a manufacturing procedure of a circuit board used for manufacturing the semiconductor device having the configuration described in the embodiment, and FIG. 6 is a cross-sectional process diagram (part 2). A procedure for manufacturing a circuit board used in the embodiment will be described below based on these drawings.

[FIG. 5A]
First, as shown in FIG. 5A, a semiconductor substrate 50 made of, for example, single crystal silicon is prepared. On the surface layer of the semiconductor substrate 50, the source / drain 51 of each conductivity type and other impurity layers not shown here are formed. Further, a gate insulating film 53 is formed on the surface of the semiconductor substrate 50, and a gate electrode 55 is formed thereon. The gate electrode 55 is formed between the source / drain 51. In the same process, another electrode not shown here is formed.

  Thereafter, an interlayer insulating film 57 made of, for example, silicon oxide is formed on the semiconductor substrate 50 so as to cover the gate electrode 55.

  Next, a groove pattern 57 a is formed in the interlayer insulating film 57. The groove pattern 57a is formed in a shape that reaches the gate electrode 55 at a required position. Although illustration is omitted here, a groove pattern reaching the source / drain 51 is formed in the interlayer insulating film 57 and the gate insulating film 53 at necessary portions. Next, a barrier metal layer 59a is formed in a state in which the inner wall of the groove pattern 57a is covered, and a wiring layer 59b made of copper (Cu) is formed in a state in which the groove pattern 57a is embedded thereon, and then the wiring layer is formed by CMP. 59b and the barrier metal layer 59a are sequentially planarized and removed. Thus, an embedded wiring 59 is formed by embedding the wiring layer 59b in the groove pattern 57a via the barrier metal layer 59a, and the first wiring layer 7b having the embedded wiring 59 is obtained.

[FIG. 5B]
Next, as shown in FIG. 5B, an interlayer insulating film 63 is deposited on the first wiring layer 7b via the diffusion preventing insulating film 61, and a groove is formed in the interlayer insulating film 63 and the diffusion preventing insulating film 61. Pattern 63a. This groove pattern 63a is formed so as to reach the buried wiring 59 in the lower layer at a place as necessary. Thereafter, in the same manner as the formation procedure of the first wiring layer 7b, an embedded wiring 65 is formed by embedding the wiring layer 65b in the groove pattern 63a through the barrier metal layer 65a, thereby obtaining the second wiring layer 7c. .

  The steps up to the above may be performed by a normal process procedure, and the process procedure is not particularly limited, and can be performed by an appropriate procedure. In the present technology, the following steps are characteristic steps.

[FIG. 5C]
That is, first, as shown in FIG. 5C, a second insulating film 69 is formed on the second wiring layer 7c. The second insulating film 69 is formed using a diffusion preventing material for the material constituting the second electrode film to be formed next. For example, when the second electrode film is made of copper (Cu), the second insulating film 69 is made of the same material as the first insulating film (35) on the sensor substrate (2) side described above, and is formed in the same manner. Be filmed.

  Next, a groove pattern 69 a is formed in the second insulating film 69. The groove pattern 69a has a shape in which the electrode pad is embedded, and reaches the embedded wiring 65 formed in the second wiring layer 7c at a necessary position. The groove pattern 69a is formed in the same manner as the groove pattern 35a formed in the first insulating film (35) on the sensor substrate (2) side described above.

[FIG. 6A]
Next, as shown in FIG. 6A, the second electrode film 67a is directly formed on the second insulating film 69 in a state where the groove pattern 69a is embedded. The second electrode film 67a is made of a material that is prevented from diffusing into the second insulating film 69, and is made of, for example, copper (Cu). The second electrode film 67a is formed by, for example, a plating method using a seed layer as an electrode after forming a thin seed layer by sputtering.

[FIG. 6B]
Next, as shown in FIG. 6B, the second electrode film 67a is planarized and removed by CMP until the second insulating film 69 is exposed. Similar to the planarization of the first electrode film 33a described with reference to FIG. 4C, the second electrode film 67a is planarized by using the second insulating film 69 as a polishing stopper and surrounding the second insulating film 69 in the polishing surface. In order from the exposed second electrode film 67a, polishing is performed by CMP so that polishing automatically stops.

  Thus, the second electrode 67 is formed by embedding the second electrode film 67a in the groove pattern 69a, and the electrode layer 7d provided with the second electrode 67 as the embedded electrode is obtained. Thereby, the circuit board 7 having the flat bonding surface 71 composed of the second electrode 67 and the second insulating film 69 is manufactured as the second substrate.

≪5. Bonding of substrates in manufacturing of semiconductor device of embodiment >>
Next, a bonding procedure between the sensor substrate 2 on which the flat bonding surface 41 is formed and the circuit board 7 on which the flat bonding surface 71 is formed will be described with reference to FIGS. 7 and 8.

[Fig. 7]
First, as shown in FIG. 7, the sensor substrate 2 and the circuit substrate 7 manufactured by the above-described procedure are arranged to face each other with the flat bonding surface 41 and the bonding surface 71 facing each other. Furthermore, the sensor board 2 and the circuit board 7 are aligned so that the first electrode 33 on the sensor board 2 side corresponds to the second electrode 67 on the circuit board 7 side. In the illustrated example, a state in which the first electrode 33 and the second electrode 67 correspond 1: 1 is shown, but the correspondence state is not limited to this.

  Note that the bonding surface 41 of the sensor substrate 2 and the bonding surface 71 of the circuit board 7 are subjected to a pretreatment for bonding by wet treatment or plasma treatment as necessary.

[Fig. 8]
Next, as shown in FIG. 8, the sensor substrate 2 and the circuit substrate 7 are laminated by bringing the bonding surface 41 and the bonding surface 71 into contact with each other. By performing heat treatment in this state, the first electrode 33 on the bonding surface 41 and the second electrode 67 on the bonding surface 71 are joined. The first insulating film 35 on the bonding surface 41 and the second insulating film 69 on the bonding surface 71 are joined. Such heat treatment is sufficient for the electrodes 33 and 67 within the range that does not affect the elements and wirings formed on the sensor substrate 2 and the circuit substrate 7 by the material constituting the first electrode 33 and the second electrode 67. Is performed at a temperature and a time for bonding.

  For example, when the 1st electrode 33 and the 2nd electrode 67 are comprised with the material which mainly has copper (Cu), the heat processing for about 1 to 5 hours are performed at 200 to 600 degreeC. Such heat treatment may be performed in a pressurized atmosphere, or may be performed in a state where the sensor substrate 2 and the circuit substrate 7 are pressed from both sides. As an example, Cu—Cu bonding is performed by performing heat treatment at 400 ° C. for 4 hours.

  After the sensor substrate 2 and the circuit board 7 are laminated as described above and bonded between the bonding surfaces 41-71, the semiconductor substrate 20 on the sensor substrate 2 side is thinned to form the semiconductor layer 2a. The photoelectric conversion unit 21 is exposed. If necessary, the semiconductor substrate 50 on the circuit board 7 side is thinned to form a semiconductor layer 7a.

[Figure 2]
Thereafter, as shown in FIG. 2, a protective film 15 is formed on the exposed surface of the photoelectric conversion unit 21 in the sensor substrate 2, and a color filter layer 17 and an on-chip lens 19 are formed on the protective film 15, A semiconductor device (solid-state imaging device) 1 is completed.

[Operational Effects of Semiconductor Device Manufacturing Method of Embodiment]
According to the manufacturing method of the embodiment described above, as described with reference to FIG. 4C, in the formation of the sensor substrate 2, the first electrode film 33 a directly formed on the first insulating film 35 is formed using the first electrode film 33 a. The planarization is removed by CMP using the insulating film 35 as a polishing stopper. At this time, by performing CMP in which the polishing is automatically stopped in order from the first electrode film 33a portion where the first insulating film 35 is exposed in the periphery, it is possible to prevent the occurrence of dishing and erosion on the entire polishing surface, A flat polished surface can be obtained as the bonding surface 41.

  Also in the process described with reference to FIG. 6B, a flat polished surface can be obtained as the bonding surface 71 as described above.

  Therefore, in the bonding process described with reference to FIGS. 7 and 8, the sensor substrate 2 and the circuit board 7 are bonded between the flat bonding surface 41 and the bonding surface 71. Can do. Thereby, the bonding in which the good bonding between the electrodes 33 and 67 is performed between the entire surface of the bonding surface 41 and the bonding surface 71, and the bonding strength between the sensor substrate 2 and the circuit substrate 7 can be maintained. It becomes possible.

  Furthermore, the first insulating film 35 constituting the bonding surface 41 on the sensor substrate 2 side is made of a diffusion preventing material for the first electrode 33. For this reason, the diffusion of the first electrode 33 into the first insulating film 35 can be prevented. Similarly, the second insulating film 69 constituting the bonding surface 71 on the circuit board 7 side is made of a diffusion preventing material for the second electrode 67. For this reason, the diffusion of the second electrode 67 into the second insulating film 69 can be prevented. Accordingly, it is possible to realize the bonding while maintaining the bonding strength between the electrodes 33-67 as described above.

  In addition, the first insulating film 35 on the sensor substrate 2 side is configured by the diffusion preventing material for the second electrode 67 on the circuit board 7 side, and the first insulating film 35 on the circuit board 7 side is formed by the diffusion preventing material for the first electrode 33 on the sensor substrate 2 side. Two insulating films 69 are formed. Thereby, the mutual diffusion of the electrode material between the sensor substrate 2 and the circuit substrate 7 can also be prevented.

  In addition, the bonding surface 41 on the sensor substrate 2 side includes only the first electrode 33 and the first insulating film 35, and the bonding surface 71 on the circuit substrate 7 side includes only the second electrode 67 and the second insulating film 69. It is configured. For this reason, the bonding surfaces 41 and 71 are not constituted by the barrier metal layer that is chemically inert and does not easily maintain the bonding strength, and the configuration of the bonding surfaces is simplified, and the bonding strength is also maintained by this. Is possible.

  Here, FIG. 9 shows a manufacturing procedure of a semiconductor device as a comparative example. The procedure of the comparative example shown in FIG. 9 is performed as follows.

  First, as shown in FIG. 9A, a groove pattern 101a is formed in a first insulating film 101 covering one substrate surface, and a barrier metal layer 102 for an electrode material is formed along the groove pattern 101a. A first electrode film 103a made of copper (Cu) is formed. Next, as shown in FIG. 9B, the first electrode film 103a is planarized and removed by CMP, and the barrier metal layer 102 is exposed. At this time, CMP is performed using the barrier metal layer 102 as a polishing stopper. Further, in this CMP, CMP is performed such that polishing automatically stops in order from the first electrode film 103a portion where the barrier metal layer 102 is exposed in the polishing surface.

  Thereafter, as shown in FIG. 9C, the barrier metal layer 102 is planarized and removed by polishing, and the first insulating film 101 is exposed. Thus, the first electrode 103 is formed in which the first electrode film 103a made of copper (Cu) is embedded in the groove pattern 101a of the first insulating film 101 with the barrier metal layer 102 interposed therebetween.

  On the other hand, as shown in FIGS. 9A ′ to 9C ′, copper (Cu) is also formed on the surface of the other substrate in the groove pattern 201a of the second insulating film 201 through the barrier metal layer 202 in the same procedure. A second electrode 203 in which a second electrode film 203a made of is embedded is formed.

  Thereafter, as shown in FIG. 9D, the respective polished surfaces are arranged to face each other, and the first electrode 103 and the second electrode 203 are bonded to each other so as to bond the two substrates.

  In the procedure of such a comparative example, in the polishing of the barrier metal layer 102 and the first electrode film 103a from FIG. 9B to FIG. 9C, the first electrode film 103a made of chemically active copper (Cu) is rapidly applied. There is no change in the exposed area. For this reason, it is not possible to perform CMP in which polishing is automatically stopped sequentially from the first electrode film 103a portion where the first insulating film 101 is exposed in the periphery. Therefore, it is difficult to prevent dishing or erosion from occurring on the polished surface, and it is difficult to obtain a flat polished surface. The same applies to the process shown in FIG. 9C '.

  Accordingly, as shown in FIG. 9D, even if the polished surfaces having poor flatness are opposed to each other and the substrates are bonded to each other, sufficient bonding strength cannot be obtained, and the first electrode 103 and the second electrode A sufficient bonding strength with the electrode 203 cannot be obtained.

  9C includes the first insulating film 101, the barrier metal layer 102, and the first electrode 103. On the other hand, the polished surface shown in FIG. 9C ′ is also composed of the second insulating film 201, the barrier metal layer 202, and the second electrode 203. For this reason, the bonding interface between the polished surfaces is the bonding interface between the first insulating film 101 and the first electrode 103 and the barrier metal layer 202, and the second insulating film 201 and the second electrode 203 and the barrier metal layer 102. A bonding interface is also generated. However, since the barrier metal layers 102 and 202 are chemically inactive, it is difficult to perform pretreatment by plasma treatment or wet treatment at the time of bonding. For this reason, in the part where the barrier metal layers 102 and 202 are exposed on the bonding surface, the bonding strength cannot be obtained, which causes a decrease in the bonding strength between the substrates.

  In contrast to the comparative example as described above, in the semiconductor device of this embodiment shown in FIG. 2, the first electrode 33 and the first insulating film 35, the second electrode 67 and the second insulating film 69 are divided into two types, respectively. Bonding is performed between the simplified flat bonding surface 41 and the bonding surface 71. Between the first electrode 33 and the second electrode 67, between the first insulating film 35 and the second insulating film 69, between the first electrode 33 and the second insulating film 69, and between the second electrode and the first insulating film 35. It is possible to obtain a sufficient bonding strength. For this reason, a sufficient bonding strength can be obtained between the sensor substrate (first substrate) 2 and the circuit substrate (second substrate) 7.

≪6. Modified Example of Semiconductor Device of Embodiment >>
FIG. 10 is a cross-sectional view of a main part of a semiconductor device which is a modification of the embodiment. As shown in this figure, the sensor substrate 2 as the first substrate may be provided with a first insulating film 35 ′ using an interlayer insulating film 35-1 and a diffusion preventing insulating film 35-2. In this case, for example, a groove pattern 35a is provided in the interlayer insulating film 35-1 using silicon oxide or a low dielectric constant material, and diffusion is performed while covering the interlayer insulating film 35-1 including the inner wall of the groove pattern 35a. A prevention insulating film 35-2 is provided. A first electrode 33 is provided in the groove pattern 35a via a diffusion prevention insulating film 35-2. Thereby, the periphery of the first electrode 33 is surrounded by the diffusion preventing insulating film 35-2, and the bonding surface 41 is configured by the first electrode 33 and the diffusion preventing insulating film 35-2.

  Similarly, a second insulating film 69 ′ using the interlayer insulating film 69-1 and the diffusion prevention insulating film 69-2 may be provided on the circuit board 7 as the second substrate. Thereby, the periphery of the second electrode 67 is surrounded by the diffusion preventing insulating film 69-2, and the bonding surface 71 is constituted by the second electrode 67 and the diffusion preventing insulating film 69-2.

  Even in the semiconductor device 1 ′ having such a configuration, the bonding surface 41 of the sensor substrate 2 and the bonding surface 71 of the circuit board 7 are connected to the diffusion prevention insulating films 35-2 and 69-2 and the electrode 33. It is possible to ensure the bonding strength by constituting only 67. In addition, it is possible to prevent the material constituting the electrodes 33 and 67 from diffusing into the interlayer insulating films 35-1 and 69-1.

  As a result, in the semiconductor device 1 ′ having a three-dimensional structure in which the first electrode 33 and the second electrode 67 are bonded by bonding the two substrates 2-7, bonding is performed while preventing diffusion of the electrode material. Strength is ensured and reliability can be improved.

  In the manufacture of the semiconductor device 1 ′ having the above-described configuration, when the sensor substrate 2 as the first substrate is manufactured, the film constituting the first electrode 33 is formed by CMP using the diffusion prevention insulating film 35-2 as a stopper. It only has to be polished. For this reason, it is possible to accurately detect the time when the diffusion preventing insulating film 35-2 is exposed as an end point of polishing, and to finish the CMP without causing dishing to obtain a flat polished surface as the bonding surface 41. Is possible.

  Similarly, when the circuit board 7 which is the second substrate is manufactured, the film constituting the second electrode 67 may be polished by CMP using the diffusion prevention insulating film 69-2 as a stopper. For this reason, a flat polished surface can be obtained as the bonding surface 71 in the same manner.

  As a result, similarly to the manufacturing method of the previous embodiment, bonding is performed between the entire surfaces of the bonding surface 41 and the bonding surface 71, and the bonding strength between the sensor substrate 2 and the circuit substrate 7 is increased. It becomes possible to keep. In addition, the diffusion prevention insulating film 35-2 on the sensor substrate 2 side is configured by the diffusion prevention material for the second electrode 67 on the circuit board 7 side, and the circuit board 7 side is formed by the diffusion prevention material for the first electrode 33 on the sensor board 2 side. The diffusion prevention insulating film 69-2 may be configured. Thereby, diffusion of the electrode material between the sensor substrate 2 and the circuit substrate 7 can also be prevented. In addition, the bonding surface 41 on the sensor substrate 2 side includes only the first electrode 33 and the diffusion preventing insulating film 35-2, and the bonding surface 71 on the circuit board 7 side includes the second electrode 67 and the diffusion preventing insulating film 69. It consists only of -2. For this reason, the structure of a bonding surface is simplified and it becomes possible to maintain joining strength also by this.

≪7. Example of Electronic Device Using Semiconductor Device of Embodiment >>
The semiconductor device (solid-state imaging device) according to the present technology described in the above-described embodiments is, for example, a camera system such as a digital camera or a video camera, a mobile phone having an imaging function, or other equipment having an imaging function. It can be applied to other electronic devices.

  FIG. 11 is a configuration diagram of a camera using a solid-state imaging device as an example of an electronic apparatus according to the present technology. The camera according to the present embodiment is an example of a video camera capable of capturing still images or moving images. The camera 90 includes a solid-state imaging device 91, an optical system 93 that guides incident light to the light receiving sensor unit of the solid-state imaging device 91, a shutter device 94, a drive circuit 95 that drives the solid-state imaging device 91, and the solid-state imaging device 91. And a signal processing circuit 96 for processing the output signal.

  As the solid-state imaging device 91, the semiconductor device (1, 1 ') having the configuration described in the above-described embodiments and modifications is applied. The optical system (optical lens) 93 forms image light (incident light) from the subject on the imaging surface of the solid-state imaging device 91. Thereby, signal charges are accumulated in the solid-state imaging device 91 for a certain period. Such an optical system 93 may be an optical lens system including a plurality of optical lenses. The shutter device 94 controls the light irradiation period and the light shielding period for the solid-state imaging device 91. The drive circuit 95 supplies drive signals to the solid-state imaging device 91 and the shutter device 94, and controls the signal output operation to the signal processing circuit 96 of the solid-state imaging device 91 and the shutter device by the supplied drive signal (timing signal). 94 shutter operation is controlled. That is, the drive circuit 95 performs a signal transfer operation from the solid-state imaging device 91 to the signal processing circuit 96 by supplying a drive signal (timing signal). The signal processing circuit 96 performs various signal processing on the signal transferred from the solid-state imaging device 91. The video signal subjected to the signal processing is stored in a storage medium such as a memory or output to a monitor.

  According to the electronic device according to the present embodiment described above, an electronic device having an imaging function is obtained by using the highly reliable three-dimensional semiconductor device 1 in which a sensor substrate and a circuit board are stacked as a solid-state imaging device. It becomes possible to reduce the size of the device and improve the reliability.

In addition, this technique can also take the following structures.
(1)
The first electrode includes a first insulating film that is made of a diffusion preventing material for the first electrode and covers the periphery of the first electrode, and a bonding surface is formed by the first electrode and the first insulating film. A first substrate,
A second electrode provided on the first substrate and bonded to the first electrode; and a second insulating film made of a diffusion preventing material for the second electrode and covering the periphery of the second electrode. A semiconductor device comprising: a second substrate in which a bonding surface for the first substrate is configured by the second electrode and the second insulating film.

(2)
The semiconductor device according to (1), wherein each of the first electrode and the second electrode is formed of a single material layer.

(3)
The semiconductor device according to (1) or (2), wherein the bonding surface of the first substrate and the bonding surface of the second substrate are configured as flat surfaces.

(4)
The first electrode is embedded in a groove pattern formed in the first insulating film,
The semiconductor device according to any one of (1) to (3), wherein the second electrode is embedded in a groove pattern formed in the second insulating film.

(5)
The bonding surface of the first substrate is composed only of the first electrode and the first insulating film,
The bonding surface of the second substrate includes only the second electrode and the second insulating film. The semiconductor device according to any one of (1) to (4).

(6)
The first insulating film is made of a diffusion preventing material for a material constituting the second electrode together with the first electrode,
The semiconductor device according to any one of (1) to (5), wherein the second insulating film is formed of a diffusion prevention material for a material forming the first electrode together with the second electrode.

(7)
The semiconductor device according to any one of (1) to (6), wherein the first electrode and the second electrode are made of the same material.

(8)
The semiconductor device according to any one of (1) to (7), wherein the first insulating film and the second insulating film are made of the same material.

(9)
Forming an insulating film made of a diffusion preventing material for the electrode material on the substrate, and forming a groove pattern in the insulating film;
Forming an electrode film made of the electrode material on the insulating film in a state of embedding the groove pattern formed in the insulating film;
Polishing the electrode film until the insulating film is exposed, patterning an electrode in which the electrode film is embedded in the groove pattern;
A method for manufacturing a semiconductor device, comprising: bonding the two substrates on which the electrodes are formed in a state in which the electrodes are bonded together.

(10)
(9) The method for manufacturing a semiconductor device according to (9), wherein when the electrode is patterned, chemical mechanical polishing is performed using the insulating film as a stopper.

(11)
When patterning the electrode, chemical mechanical polishing is performed so that polishing automatically stops in order from the electrode film portion where the insulating film is exposed to the surroundings by polishing the electrode film (9) or (10) A method for manufacturing a semiconductor device according to (10).

  DESCRIPTION OF SYMBOLS 1,1 '... Semiconductor device, 2 ... Sensor board | substrate (1st board | substrate), 7 ... Circuit board (2nd board | substrate), 33 ... 1st electrode, 33a ... 1st electrode film, 35, 35' ... 1st insulating film , 35a ... groove pattern (first substrate side), 35-1 ... interlayer insulating film (first insulating film), 35-2 ... diffusion preventing insulating film (first insulating film), 41 ... bonding surface (first substrate) Side), 67 ... second electrode, 67a ... second electrode film, 69, 69 '... second insulating film, 69a ... groove pattern (second substrate side), 69-1 ... interlayer insulating film (second insulating film) 69-2 ... Diffusion-preventing insulating film (second insulating film), 71 ... Bonding surface

Claims (13)

The first substrate and the second substrate, a semiconductor device canceller Awa attached at each lamination surface,
The bonding surface of the first substrate includes a first electrode and a first insulating film made of a diffusion preventing material for the first electrode and continuously covering the periphery of the first electrode from the bonding surface.
The bonding surface of the second substrate is made of a second electrode joined to the first electrode and a diffusion preventing material for the second electrode, and continuously covers the periphery of the second electrode from the bonding surface. A semiconductor device composed of two insulating films. The semiconductor device according to claim 1, wherein each of the first electrode and the second electrode is formed of a single material layer. The semiconductor device according to claim 1, wherein the bonding surface of the first substrate and the bonding surface of the second substrate are configured as flat surfaces. The first electrode is embedded in a groove pattern formed in the first insulating film,
The semiconductor device according to claim 1, wherein the second electrode is embedded in a groove pattern formed in the second insulating film. A first interlayer insulating film having a groove pattern in which the first electrode is embedded; and a second interlayer insulating film having a groove pattern in which the second electrode is embedded;
The first insulating film is provided in a state of covering the first interlayer insulating film including the inner wall of the groove pattern of the first interlayer insulating film,
The semiconductor device according to claim 1, wherein the second insulating film is provided so as to cover the second interlayer insulating film including an inner wall of a groove pattern of the second interlayer insulating film. The bonding surface of the first substrate is composed only of the first electrode and the first insulating film,
The semiconductor device according to claim 1, wherein a bonding surface of the second substrate includes only the second electrode and the second insulating film. The first insulating film is made of a diffusion preventing material for a material constituting the second electrode together with the first electrode,
The semiconductor device according to claim 1, wherein the second insulating film is made of a diffusion preventing material with respect to a material constituting the first electrode together with the second electrode. The semiconductor device according to claim 1, wherein the first electrode and the second electrode are made of the same material. The semiconductor device according to claim 1, wherein the first insulating film and the second insulating film are made of the same material. Forming an insulating film made of a diffusion preventing material for the electrode material on the substrate, and forming a groove pattern in the insulating film;
Forming an electrode film made of the electrode material on the insulating film in a state of embedding the groove pattern formed in the insulating film;
Polishing the electrode film until the insulating film is exposed, patterning an electrode in which the electrode film is embedded in the groove pattern;
A method for manufacturing a semiconductor device, comprising: bonding the two substrates on which the electrodes are formed in a state in which the electrodes are bonded together. The method of manufacturing a semiconductor device according to claim 10, wherein when the electrode is patterned, chemical mechanical polishing is performed using the insulating film as a stopper. 11. When patterning the electrode, chemical mechanical polishing is performed so that polishing automatically stops in order from the electrode film portion where the insulating film is exposed to the surroundings by polishing the electrode film. 11. A method for manufacturing a semiconductor device according to 11. A solid-state imaging device; an optical system that guides incident light to the solid-state imaging device; and a drive circuit that drives the solid-state imaging device;
The solid-state imaging device
The first substrate and the second substrate, Serare Awa bonded with each lamination surface,
The bonding surface of the first substrate includes a first electrode and a first insulating film made of a diffusion preventing material for the first electrode and continuously covering the periphery of the first electrode from the bonding surface.
The bonding surface of the second substrate is made of a second electrode joined to the first electrode and a diffusion preventing material for the second electrode, and continuously covers the periphery of the second electrode from the bonding surface. Electronic equipment composed of two insulating films.