Semiconductor device and manufacturing method thereof

Abstract

To provide a semiconductor device with high reliability.SOLUTION: A semiconductor device comprises: a semiconductor substrate; a first electrode that is provided onto the semiconductor substrate, and contains aluminum; a second electrode that is provided onto the semiconductor substrate so as to be separated from the first electrode, and contains aluminum; a third electrode that is provided onto the first electrode, and contains aluminum oxide; and a fourth electrode that is provided onto the second electrode, contains aluminum oxide, and of which a film thickness is 1 / 2 or less of that of the third electrode.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] 1. Field of the Invention The present invention relates to a semiconductor device and a manufacturing method thereof. [Background technology]

[0002] Semiconductor devices having semiconductor chips such as IGBTs (Insulated Gate Bipolar Transistors) or MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) are used for applications such as power conversion. For example, when the above-mentioned semiconductor device is an IGBT, an emitter electrode provided on the upper surface of the semiconductor chip is connected to, for example, a connector or a bonding wire provided on the IGBT. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-026417 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a highly reliable semiconductor device. [Means for solving the problem]

[0005] The semiconductor device of the embodiment includes a semiconductor substrate, a first electrode including aluminum provided on the semiconductor substrate, a second electrode including aluminum provided on the semiconductor substrate and spaced apart from the first electrode, a third electrode including aluminum oxide provided on the first electrode, and a fourth electrode including aluminum oxide provided on the second electrode, the fourth electrode having a thickness equal to or less than half that of the third electrode. [Brief description of the drawings]

[0006] [Figure 1] 1 is a schematic cross-sectional view of a semiconductor device according to a first embodiment. [Diagram 2] FIG. 2 is a schematic top view showing a semiconductor substrate, a first insulating film, a first electrode, and a second electrode according to the first embodiment. [Diagram 3] 1 is a schematic cross-sectional view of a main part of a semiconductor device according to a first embodiment. [Figure 4] 2A to 2C are schematic cross-sectional views showing a manufacturing process of the semiconductor device according to the first embodiment. [Diagram 5] 2A to 2C are schematic cross-sectional views showing a manufacturing process of the semiconductor device according to the first embodiment. [Figure 6] 2A to 2C are schematic cross-sectional views showing a manufacturing process of the semiconductor device according to the first embodiment. [Figure 7] 2A to 2C are schematic cross-sectional views showing a manufacturing process of the semiconductor device according to the first embodiment. [Figure 8] 4 is a flowchart showing a manufacturing process of the semiconductor device according to the first embodiment. [Figure 9] 4 is a schematic cross-sectional view of a main part of a semiconductor device serving as a first comparative example of the first embodiment. FIG. [Figure 10] 11 is a schematic cross-sectional view of a main part of a semiconductor device serving as a second comparative example of the first embodiment. FIG. [Figure 11] FIG. 11 is a schematic cross-sectional view of a semiconductor device according to a second embodiment. [Figure 12] 5A to 5C are schematic cross-sectional views showing a part of a manufacturing process of the semiconductor device according to the second embodiment. [Figure 13] FIG. 11 is a schematic cross-sectional view of a semiconductor device according to a third embodiment. [Figure 14] 10A to 10C are schematic cross-sectional views showing a manufacturing process of the semiconductor device according to the third embodiment. [Figure 15] 10A to 10C are schematic cross-sectional views showing a manufacturing process of the semiconductor device according to the third embodiment. [Figure 16] 10A to 10C are schematic cross-sectional views showing a manufacturing process of the semiconductor device according to the third embodiment. [Figure 17] 10A to 10C are schematic cross-sectional views showing main steps of a manufacturing process for a semiconductor device according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the same members are designated by the same reference numerals, and the description of members that have already been described will be omitted as appropriate.

[0008] In this specification, in order to indicate the positional relationship of parts, etc., the upward direction of the drawing is described as "upper" and the downward direction of the drawing is described as "lower." In this specification, the concepts of "upper" and "lower" are not necessarily terms that indicate a relationship with the direction of gravity.

[0009] (First embodiment) The semiconductor device of this embodiment includes a semiconductor substrate, a first electrode including aluminum provided on the semiconductor substrate, a second electrode including aluminum provided on the semiconductor substrate and spaced apart from the first electrode, a third electrode including aluminum oxide provided on the first electrode, a sixth electrode including nickel provided on the second electrode, and a seventh electrode including gold provided on the sixth electrode.

[0010] Fig. 1 is a schematic cross-sectional view of a semiconductor device 100 according to the present embodiment. Fig. 2 is a schematic top view showing a semiconductor substrate 2, a first insulating film 50, a first electrode 4, and a second electrode 6 of the semiconductor device according to the present embodiment.

[0011] FIG. 1 is a schematic cross-sectional view taken along the line AA' of FIG.

[0012] In FIG. 2, some of the components shown in FIG. 1 are omitted.

[0013] The die pad 1 is a member containing a conductive material such as Cu (copper) on which the semiconductor substrate 2 is placed. The die pad 1 is used to connect the semiconductor substrate 2 to an external circuit (not shown).

[0014] The semiconductor substrate 2 is provided on the die pad 1. The semiconductor substrate 2 has a substrate surface (upper surface) 3. The semiconductor substrate 2 of this embodiment is, for example, a substrate of Si (silicon), SiC (silicon carbide), GaAs (gallium arsenide), or the like, or a semiconductor layer of GaN (gallium nitride) provided on a Si substrate, on which a vertical IGBT or MOSFET is provided.

[0015] In the following description, the semiconductor substrate 2 is assumed to have an IGBT.

[0016] Here, an X direction, a Y direction perpendicular to the X direction, and a Z direction perpendicular to the X direction and Y direction are defined. A substrate surface 3 of the semiconductor substrate 2 is disposed parallel to the XY plane.

[0017] The first electrode 4 is provided on the substrate surface 3 of the semiconductor substrate 2. The first electrode 4 is, for example, an electrode electrically connected to the gate of the IGBT. The first electrode 4 is, for example, an electrode for Kelvin connection to the IGBT. The first electrode 4 contains, for example, Al (aluminum). The first electrode 4 is, for example, an electrode containing Al as a main component. The first electrode 4 is, for example, an Al electrode. The first electrode 4 may contain an element other than Al.

[0018] The second electrode 6 is provided on the substrate surface 3 of the semiconductor substrate 2 and spaced apart from the first electrode 4. The second electrode 6 is, for example, an electrode electrically connected to the emitter of the IGBT. The second electrode 6 contains, for example, Al (aluminum). The second electrode 6 is, for example, an electrode containing Al as a main component. The second electrode 6 is, for example, an Al electrode. Note that the second electrode 6 may contain elements other than Al.

[0019] For example, as shown in Fig. 2, a plurality of first electrodes 4 may be provided, such as first electrodes 4a, 4b, 4c, 4d, and 4e. Also, as shown in Fig. 2, a plurality of second electrodes 6 may be provided, such as second electrodes 6a and 6b.

[0020] An electrode (not shown) connected to the collector of the IGBT is provided below the semiconductor substrate 2.

[0021] The second bonding material 70 is provided between the semiconductor substrate 2 and the substrate surface 3. The second bonding material 70 electrically connects, for example, an electrode connected to the collector of the IGBT and the die pad 1. The second bonding material 70 is, for example, solder. However, the second bonding material 70 is not limited to solder.

[0022] The third electrode 8 is provided on the first electrode 4. The third electrode 8 includes aluminum oxide. The third electrode 8 is in direct contact with the first electrode 4, for example. The third electrode 8 is electrically connected to the first electrode 4.

[0023] The first bonding wire 62 breaks through the third electrode 8 and is connected to the first electrode 4, for example, by a bonding operation. As a result, the first bonding wire 62 is electrically connected to the first electrode 4. The first bonding wire 62 includes, for example, aluminum (Al). The first bonding wire 62 is, for example, an aluminum (Al) wire.

[0024] The sixth electrode 14 is provided on the second electrode 6. The sixth electrode 14 contains nickel (Ni).

[0025] The seventh electrode 16 is provided on the sixth electrode 14. The seventh electrode 16 contains gold (Au). The seventh electrode 16 is used, for example, to prevent oxidation of the sixth electrode 14. In addition, the seventh electrode 16 and the connector 60 are joined using a first bonding material 72. Here, the first bonding material 72 is, for example, solder.

[0026] Between the sixth electrode 14 and the seventh electrode 16, a layer containing palladium (Pd) (not shown) may be provided.

[0027] The connector 60 is electrically connected to the sixth electrode 14 and the seventh electrode 16. The connector 60 includes a conductive material such as copper (Cu). The surface of the connector 60 may be plated with a material including tin (Sn).

[0028] The connector 60 is a hard connector that cannot be easily bent, and is different from the first bonding wires 62.

[0029] The first insulating film 50 is provided on the semiconductor substrate 2. The first insulating film 50 has a first opening 52 and a second opening 54. The first electrode 4 and the third electrode 8 are provided inside the first opening 52. The second electrode 6, the sixth electrode 14, and the seventh electrode 16 are provided inside the second opening 54. The first insulating film 50 contains, for example, a resin such as a polyimide resin, a benzocyclobutene resin, or an epoxy resin, or silicon nitride. The first insulating film 50 is preferably resistant to a chemical solution used in an electroless nickel-gold plating process described later.

[0030] Fig. 3 is a schematic diagram of a main part of the semiconductor device 100 of this embodiment. Fig. 3(a) is a schematic cross-sectional view of the third electrode 8 and its vicinity of the semiconductor device 100 of this embodiment. Fig. 3(b) is a schematic top view of the third electrode 8 of this embodiment. Note that in Fig. 3, some of the components shown in Fig. 1 are omitted.

[0031] In a plane parallel to the XY plane, which is parallel to the substrate surface 3, the third electrode 8 has an end 7. A recess 9 is formed by surrounding it with the end 7. The length of the recess 9 in the X direction is L3. The length of the third electrode 8 in the X direction is L4. L4 is longer than L3. The length of the recess 9 in the Y direction is L1. The length of the third electrode 8 in the Y direction is L2. In a plane parallel to the XY plane, the end 7 is provided around the recess 9. L2 is longer than L1.

[0032] A first insulating film 50 is provided on the end portion 7 so as to surround the recess 9 in a plane parallel to the XY plane. A film thickness L6 of the end portion 7 in the Z direction is thicker than a film thickness L5 of the recess 9 in the Z direction.

[0033] 4 to 7 are schematic cross-sectional views showing the manufacturing process of the semiconductor device 100 of this embodiment.

[0034] FIG. 8 is a flowchart showing the manufacturing process of the semiconductor device 100 of this embodiment.

[0035] A first electrode 4 containing aluminum, and a second electrode 6 containing aluminum and spaced apart from the first electrode 4 are provided on a substrate surface 3 of a semiconductor substrate 2 having an IGBT. A photoresist 90 having a fifth opening 92 above the first electrode 4 is formed on the semiconductor substrate 2, the first electrode 4, and the second electrode 6 (FIGS. 4 and S102 in FIG. 8).

[0036] Next, for example, an ashing process is performed to remove the photoresist 90. In the ashing process, for example, high-energy oxygen plasma is irradiated onto the surface of the photoresist 90, and the carbon contained in the photoresist 90 is bonded to the oxygen plasma. In this way, the photoresist 90 is decomposed into CO2.

[0037] When the photoresist is removed by irradiation with oxygen plasma, the surface of the first electrode 4 is oxidized in the fifth opening 92, and a third electrode 8 containing aluminum oxide is formed on the first electrode 4 (FIG. 5, S104 in FIG. 8, and S106 in FIG. 8). This makes it possible to form a third electrode 8 having a thickness greater than 10 nm. The thickness L6 of the third electrode 8 formed by the method for manufacturing a semiconductor device of this embodiment is, for example, greater than 8 nm and equal to or less than 15 nm. More preferably, the thickness of the third electrode 8 formed by the method for manufacturing a semiconductor device of this embodiment is greater than 10 nm and equal to or less than 15 nm. More preferably, the thickness of the third electrode 8 formed by the method for manufacturing a semiconductor device of this embodiment is greater than 12 nm and equal to or less than 15 nm. Other than the ashing process, the third electrode 8 containing aluminum oxide can be formed by removing the photoresist 90 using, for example, an organic solvent.

[0038] Next, a first insulating film 50 is formed on the semiconductor substrate 2, the first electrode 4, and the second electrode 6. The first insulating film 50 includes a resin such as polyimide, silicon nitride, or the like. Here, the first insulating film 50 has a first opening 52 and a second opening 54. The first opening 52 is provided on the first electrode 4. The third electrode 8 is provided inside the first opening 52. The second opening 54 is provided on the second electrode 6. Here, the first insulating film 50 is formed so that the region of the third electrode 8 where the end portion 7 will be formed is covered with the first insulating film 50 (FIG. 6(b)). This is because if the surface of the first electrode 4 is exposed, an electrode containing nickel and an electrode containing gold will be formed on the first electrode 4. (FIGS. 6 and S108 in FIG. 8).

[0039] Next, the sixth electrode 14 and the seventh electrode 16 are formed in the second opening 54 on the second electrode 6 by, for example, electroless nickel-gold plating. In the electroless nickel-gold plating, first, a strongly acidic chemical solution treatment and a strongly alkaline chemical solution treatment are performed. By the strongly alkaline chemical solution treatment, even if a natural oxide film containing aluminum is formed on the second electrode 6, it is removed. Here, the film thickness of such a natural oxide film is generally 10 nm or less. On the other hand, if the film thickness of the third electrode 8 is sufficiently thick, the third electrode 8 remains on the first electrode 4 even after the strongly alkaline chemical solution treatment is performed. Here, for example, by controlling the time for which the strongly alkaline chemical solution treatment is performed and the temperature of the strongly alkaline chemical solution, it is possible to make the third electrode 8 remain on the first electrode 4. As a result, the sixth electrode 14 containing nickel is formed on the second electrode 6, and the seventh electrode 16 containing gold is formed on the sixth electrode 14 (S110 in FIG. 7 and FIG. 8).

[0040] The strong alkaline chemical treatment forms a recess 9 surrounded by the end 7 in the third electrode 8. The thickness of the recess 9 is L5, which is thinner than L6. Meanwhile, the end 7 of the third electrode 8 is covered with the first insulating film 50, so the thickness remains L6. Furthermore, no electrode containing nickel or electrode containing gold is formed on the third electrode 8.

[0041] Next, the semiconductor substrate 2 is connected to the die pad 1 using the second bonding material 70, the first bonding wire 62 is connected to the first electrode 4, and the connector 60 is electrically connected to the sixth electrode 14 and the seventh electrode 16 using the first bonding material 72, thereby obtaining the semiconductor device 100 of this embodiment.

[0042] Next, the effects of the semiconductor device and the method for manufacturing the semiconductor device according to this embodiment will be described.

[0043] When a connector is used to electrically connect a semiconductor substrate having an IGBT or the like to an external circuit, a method using, for example, solder as a bonding material is used. Here, there is a problem that the solder does not wet and spread on an electrode mainly composed of aluminum. Therefore, for example, an electrode containing nickel and gold is formed on an electrode containing aluminum by an electroless nickel-gold plating method. The electroless nickel-gold plating method makes it possible to selectively form a nickel plating film on an electrode mainly composed of aluminum. Furthermore, it is possible to selectively form a metal on the nickel plating film.

[0044] On the other hand, when a bonding wire is used to electrically connect a semiconductor substrate having an IGBT or the like to an external circuit, an aluminum wire is often used. When bonding is performed using an aluminum wire, wedge bonding is mainly performed by bonding between aluminum and aluminum. Therefore, it is required that a material containing aluminum is exposed on the outermost surface of an electrode whose main component is aluminum.

[0045] By using a connector to bond, it is possible to improve the heat dissipation characteristics from the semiconductor substrate. On the other hand, in the case of bonding using a bonding wire, it is possible to reduce the mounting area of ​​a semiconductor package using a semiconductor device. Therefore, it is conceivable to bond a connector to an electrode for which it is preferable to ensure heat dissipation characteristics, and to bond a bonding wire to an electrode for which ensuring heat dissipation characteristics is not important.

[0046] 9 shows a schematic cross-sectional view of a main part of a semiconductor device 1000 serving as a first comparative example of this embodiment. In the semiconductor device 1000, a sixth electrode 14 containing nickel (Ni) is provided on the second electrode 6. In addition, a seventh electrode 16 containing gold (Au) is provided on the sixth electrode 14.

[0047] Furthermore, a ninth electrode 1014 containing nickel (Ni) is provided on the first electrode 4. Furthermore, a tenth electrode 1016 containing gold (Au) is provided on the ninth electrode 1014.

[0048] In manufacturing the semiconductor device 1000, a simple electroless nickel-gold plating method is applied, whereby electrodes containing nickel and gold are formed on both the first electrode 4 and the second electrode 6.

[0049] If an electroless nickel-gold plating method is simply applied as in the semiconductor device 1000, electrodes containing nickel and electrodes containing gold are formed on all of the electrodes, which causes a problem that it becomes impossible to connect bonding wires.

[0050] 10 shows a schematic cross-sectional view of a main part of a semiconductor device 1100 as a second comparative example of this embodiment. In the semiconductor device 1100, the sixth electrode 14 and the seventh electrode 16 are formed on the second electrode 6 by a sputtering device using a metal mask (not shown) or the like. However, if the metal mask and the first insulating film 50 are misaligned, the electrode 17, which is a part of the sixth electrode 14, and the electrode 18, which is a part of the seventh electrode 16, may be formed on the first insulating film 50. In this case, the stress caused by the electrodes 17 and 18 causes a malfunction in the connection with the connector 60, resulting in a problem of a decrease in reliability of the semiconductor device 100.

[0051] Therefore, the semiconductor device of this embodiment includes a semiconductor substrate, a first electrode containing aluminum provided on the semiconductor substrate, a second electrode containing aluminum provided on the semiconductor substrate and spaced apart from the first electrode, a third electrode provided on the first electrode and containing aluminum oxide, a sixth electrode provided on the second electrode and containing nickel, and a seventh electrode provided on the sixth electrode and containing gold.

[0052] According to the semiconductor device of this embodiment, the third electrode 8 containing aluminum oxide, and the sixth electrode 14 and the seventh electrode 16 can both be provided on one semiconductor substrate 2. Therefore, the connector 60 can be bonded onto the sixth electrode 14 and the seventh electrode 16 via the first bonding material 72. Furthermore, the first bonding wire 62 can be connected onto the third electrode 8. Therefore, it is possible to obtain a highly reliable semiconductor device.

[0053] By the above manufacturing method, the first insulating film 50 is provided on the end 7 of the third electrode 8 in the direction parallel to the substrate surface 3 of the semiconductor substrate 2. In addition, the film thickness L6 of the end 7 of the third electrode 8 is thicker than the film thickness L5 of the recess 9 of the third electrode 8.

[0054] According to the semiconductor device of the present embodiment, it is possible to provide a highly reliable semiconductor device. Also, according to the manufacturing method of the semiconductor device of the present embodiment, it is possible to provide a manufacturing method of the semiconductor device that can manufacture a highly reliable semiconductor device.

[0055] Second embodiment The semiconductor device of this embodiment includes a semiconductor substrate, a first electrode containing aluminum provided on the semiconductor substrate, a second electrode containing aluminum provided on the semiconductor substrate and spaced apart from the first electrode, a third electrode containing aluminum oxide provided on the first electrode, and a fourth electrode containing aluminum oxide provided on the second electrode, the fourth electrode having a thickness equal to or less than half that of the third electrode.

[0056] Here, the description of the contents that overlap with the first embodiment will be omitted.

[0057] 11 is a schematic cross-sectional view of a semiconductor device 200 of this embodiment. A fourth electrode 10 containing aluminum oxide is provided on the second electrode 6. The film thickness L7 of the fourth electrode 10 is half or less of the film thickness L6 of the end portion 7 of the third electrode 8.

[0058] Moreover, the second bonding wire 66 breaks through the fourth electrode 10 and is connected to the second electrode 6, for example, by an operation during bonding. As a result, the second bonding wire 66 is electrically connected to the second electrode 6. The second bonding wire 66 includes, for example, aluminum (Al). The second bonding wire 66 is, for example, an aluminum (Al) wire.

[0059] As shown in FIG. 3(a) and FIG. 3(b), the third electrode 8 has a recess 9 surrounded by the end 7 in a plane parallel to the substrate surface 3 and parallel to the XY plane. The length of the recess 9 in the X direction is L3. The length of the third electrode 8 in the X direction is L4. The length of the recess 9 in the Y direction is L1. The length of the third electrode 8 in the Y direction is L2. In the plane parallel to the XY plane, the end 7 is provided around the recess 9. A first insulating film 50 is provided on the end 7 so as to surround the recess 9 in the plane parallel to the XY plane. The film thickness L6 of the end 7 in the Z direction is thicker than the film thickness L5 of the recess 9 in the Z direction.

[0060] FIG. 12 is a schematic cross-sectional view showing a part of the manufacturing process of the semiconductor device 200 of this embodiment.

[0061] For example, as shown in FIG. 12, a photoresist 90 is formed such that the film thickness L11 of the photoresist 90 on the second electrode 6 is thinner than the film thickness L10 of the photoresist 90 on the substrate surface 3 of the semiconductor substrate 2 between the first electrode 4 and the second electrode 6. This allows the photoresist 90 to be removed by ashing more quickly on the second electrode 6 than on other portions. For this reason, it is possible to form a fourth electrode 10 containing aluminum oxide and having a film thickness thinner than that of the third electrode 8 on the second electrode 6. By controlling the film thickness of the photoresist 90 on the second electrode 6, it is possible to control the relationship between the film thicknesses of the third electrode 8 and the fourth electrode 10.

[0062] According to the semiconductor device of the present embodiment, it is possible to provide a highly reliable semiconductor device. Also, according to the manufacturing method of the semiconductor device of the present embodiment, it is possible to provide a manufacturing method of the semiconductor device that can manufacture a highly reliable semiconductor device.

[0063] Third embodiment The semiconductor device of this embodiment differs from the semiconductor devices of the first and second embodiments in that the first insulating film contains silicon oxide or silicon nitride, the semiconductor device is provided on the first insulating film, has a third opening provided on the first opening and a fourth opening provided on the second opening, and further includes a second insulating film containing a resin. Here, descriptions of contents that overlap with the first and second embodiments will be omitted.

[0064] FIG. 13 is a schematic cross-sectional view of a semiconductor device 300 of the present embodiment.

[0065] The first insulating film 50 of the semiconductor device 300 of this embodiment includes, for example, silicon oxide or silicon nitride.

[0066] The second insulating film 56 is provided on the first insulating film 50. The second insulating film 56 has a third opening 57 and a fourth opening 58. The third opening 57 is provided on the first opening 52. The fourth opening 58 is provided on the second opening 54. The second insulating film 56 contains a resin such as a polyimide resin, a benzocyclobutene resin, or an epoxy resin.

[0067] 14 to 16 are schematic cross-sectional views showing the manufacturing process of the semiconductor device 300 of this embodiment.

[0068] A first insulating film 50 containing silicon oxide or silicon nitride and having a first opening 52 is formed on the first electrode (FIG. 14). Next, when irradiating oxygen plasma by, for example, an ashing process, a third electrode 8 containing aluminum oxide is formed on the first electrode 4 in the first opening 52. Next, a second opening 54 is formed on the second electrode 6 (FIG. 15). Next, a sixth electrode 14 and a seventh electrode 16 are formed on the second electrode 6 by electroless nickel-gold plating. Next, a second insulating film 56 having a third opening provided on the first opening and a fourth opening provided on the second opening is formed on the first insulating film 50 (FIG. 16).

[0069] As in this embodiment, the first insulating film 50 containing silicon oxide or silicon nitride can also be used as a mask material when forming the third electrode 8 containing aluminum oxide.

[0070] According to the semiconductor device of the present embodiment, it is possible to provide a highly reliable semiconductor device. Also, according to the manufacturing method of the semiconductor device of the present embodiment, it is possible to provide a manufacturing method of the semiconductor device that can manufacture a highly reliable semiconductor device.

[0071] (Fourth embodiment) 17A to 17C are schematic cross-sectional views showing the main steps of the method for manufacturing a semiconductor device according to the present embodiment.

[0072] A protective material P having an opening P1 is formed on an aluminum base material 5 formed on a semiconductor substrate 2. Next, the semiconductor device in the middle of manufacture is immersed in a chromic acid aqueous solution S in a container V. The protective material P is resistant to the chromic acid aqueous solution S. Examples of the protective material P that can be used include photoresist, a metal thin film containing gold or platinum, silicon oxide, and silicon nitride. Then, a third electrode 8 is formed by anodizing using the chromic acid aqueous solution S. When anodizing is used, a third electrode 8 having a film thickness of up to about 100 nm can be formed.

[0073] According to the semiconductor device of the present embodiment, it is possible to provide a highly reliable semiconductor device. Also, according to the manufacturing method of the semiconductor device of the present embodiment, it is possible to provide a manufacturing method of the semiconductor device that can manufacture a highly reliable semiconductor device.

[0074] Although some embodiments and examples of the present invention have been described, these embodiments and examples are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims.

[0075] The above-described embodiment can be summarized as the following technical proposal. (Technical proposal 1) A semiconductor substrate; a first electrode including aluminum provided on the semiconductor substrate; a second electrode including aluminum provided on the semiconductor substrate and spaced apart from the first electrode; a third electrode including aluminum oxide provided on the first electrode; a fourth electrode provided on the second electrode, containing aluminum oxide and having a thickness half or less than that of the third electrode; A semiconductor device comprising: (Technical proposal 2) provided on the semiconductor substrate, a first opening in which the first electrode and the third electrode are provided; a second opening in which the second electrode and the fourth electrode are provided; A first insulating film having the third electrode has a recess surrounded by an end portion in a plane parallel to an upper surface of the semiconductor substrate, the first insulating film is provided on an end of the third electrode so as to surround the recess in a plane parallel to an upper surface of the semiconductor substrate; A semiconductor device according to technical proposal 1. (Technical proposal 3) A semiconductor substrate; a first electrode including aluminum provided on the semiconductor substrate; a second electrode including aluminum provided on the semiconductor substrate and spaced apart from the first electrode; a third electrode provided on the first electrode and including aluminum oxide; a sixth electrode provided on the second electrode and including nickel; a seventh electrode provided on the sixth electrode and including gold; A semiconductor device comprising: (Technical proposal 4) provided on the semiconductor substrate, a first opening in which the first electrode and the third electrode are provided; a second opening in which the second electrode, the sixth electrode, and the seventh electrode are provided; A first insulating film having the third electrode has a recess surrounded by an end portion in a plane parallel to an upper surface of the semiconductor substrate, the first insulating film is provided on an end of the third electrode so as to surround the recess in a plane parallel to an upper surface of the semiconductor substrate; A semiconductor device according to technical proposal 3. (Technical proposal 5) The third electrode has a thickness of more than 10 nm. A semiconductor device according to technical proposal 3 or technical proposal 4. (Technical proposal 6) a length of the first opening above the third electrode in a direction parallel to the top surface of the semiconductor substrate is shorter than a length of the third electrode in a direction parallel to the top surface of the semiconductor substrate; A semiconductor device according to technical proposal 2, technical proposal 4 or technical proposal 5. (Technical proposal 7) the first insulating film contains silicon oxide or silicon nitride, The semiconductor device includes: a second insulating film including a resin and provided on the first insulating film, the second insulating film having a third opening provided on the first opening and a fourth opening provided on the second opening; The semiconductor device according to any one of technical proposals 2, 4 to 6, further comprising: (Technical proposal 8) forming a photoresist having a fifth opening on a semiconductor substrate, a first electrode including aluminum provided on the semiconductor substrate, and a second electrode including aluminum provided on the semiconductor substrate and spaced apart from the first electrode; removing the photoresist; forming a third electrode including aluminum oxide on the first electrode in the fifth opening when the photoresist is removed; On the semiconductor substrate, the first electrode, and the second electrode, a first opening is provided on the first electrode, the first opening being covered with a first insulating film above a region of the end of the third electrode, the first opening being provided inside the first opening, the first opening being provided in a plane parallel to an upper surface of the semiconductor substrate, the first opening being provided so as to surround a recess of the third electrode and an end of the third electrode being provided so as to surround the recess; a second opening above the second electrode; forming the first insulating film; forming a sixth electrode including nickel on the second electrode and a seventh electrode including gold on the sixth electrode in the second opening by an electroless nickel-gold plating process; forming a recess in the third electrode by the electroless nickel-gold plating process, the recess being surrounded by the end portion; A method for manufacturing a semiconductor device. (Technical proposal 9) forming a photoresist having a thickness on the second electrode that is thinner than a thickness of the photoresist on a top surface of the semiconductor substrate between the first electrode and the second electrode; When forming the third electrode, a fourth electrode containing aluminum oxide and having a film thickness equal to or less than half that of the third electrode is formed on the second electrode. A method for manufacturing a semiconductor device according to Technical Proposal 8. [Explanation of symbols]

[0076] 2. Semiconductor Substrate 3 Top surface 4 1st electrode 6 Second electrode 7 End 8 Third electrode 9 Recess 10 4th electrode 14 6th electrode 16 7th electrode 50 First insulating film 52 First opening 54 Second Opening 56 Second insulating film 57 Third Opening 58 4th opening 70 1st bonding material 100 Semiconductor device 200 Semiconductor device 300 Semiconductor device

Claims

1. A semiconductor substrate; a first electrode including aluminum provided on the semiconductor substrate; a second electrode including aluminum provided on the semiconductor substrate and spaced apart from the first electrode; a third electrode including aluminum oxide provided on the first electrode; a fourth electrode provided on the second electrode, containing aluminum oxide and having a thickness equal to or less than half that of the third electrode; A semiconductor device comprising:

2. provided on the semiconductor substrate, a first opening in which the first electrode and the third electrode are provided; a second opening in which the second electrode and the fourth electrode are provided; A first insulating film having the third electrode has a recess surrounded by an end portion in a plane parallel to an upper surface of the semiconductor substrate, the first insulating film is provided on an end of the third electrode so as to surround the recess in a plane parallel to an upper surface of the semiconductor substrate; The semiconductor device according to claim 1.

3. A semiconductor substrate; a first electrode including aluminum provided on the semiconductor substrate; a second electrode including aluminum provided on the semiconductor substrate and spaced apart from the first electrode; a third electrode provided on the first electrode and including aluminum oxide; a sixth electrode provided on the second electrode and including nickel; a seventh electrode provided on the sixth electrode and including gold; A semiconductor device comprising:

4. provided on the semiconductor substrate, a first opening in which the first electrode and the third electrode are provided; a second opening in which the second electrode, the sixth electrode, and the seventh electrode are provided; A first insulating film having the third electrode has a recess surrounded by an end portion in a plane parallel to an upper surface of the semiconductor substrate, the first insulating film is provided on an end of the third electrode so as to surround the recess in a plane parallel to an upper surface of the semiconductor substrate; 4. The semiconductor device according to claim 3.

5. The film thickness of the third electrode is greater than 10 nm.

5. The semiconductor device according to claim 3.

6. a length of the first opening above the third electrode in a direction parallel to the top surface of the semiconductor substrate is shorter than a length of the third electrode in a direction parallel to the top surface of the semiconductor substrate; 5. The semiconductor device according to claim 2.

7. the first insulating film contains silicon oxide or silicon nitride, The semiconductor device includes: a second insulating film including a resin and provided on the first insulating film, the second insulating film having a third opening provided on the first opening and a fourth opening provided on the second opening; The semiconductor device according to claim 2 or 4, further comprising:

8. forming a photoresist having a fifth opening on a semiconductor substrate, a first electrode including aluminum provided on the semiconductor substrate, and a second electrode including aluminum provided on the semiconductor substrate and spaced apart from the first electrode; removing the photoresist; forming a third electrode including aluminum oxide on the first electrode in the fifth opening when the photoresist is removed; on the semiconductor substrate, the first electrode, and the second electrode, a first opening is provided on the first electrode, the first opening being covered with a first insulating film above a region of the end of the third electrode, the first opening being provided inside the first opening, the third electrode being provided within a plane parallel to an upper surface of the semiconductor substrate, and a recess of the third electrode and an end of the third electrode being provided so as to surround the recess; a second opening above the second electrode; forming the first insulating film; forming a sixth electrode including nickel on the second electrode and a seventh electrode including gold on the sixth electrode in the second opening by electroless nickel-gold plating; forming a recess in the third electrode by the electroless nickel-gold plating process, the recess being surrounded by the end portion; A method for manufacturing a semiconductor device.

9. forming a photoresist having a thickness on the second electrode that is thinner than a thickness of the photoresist on a top surface of the semiconductor substrate between the first electrode and the second electrode; When forming the third electrode, a fourth electrode containing aluminum oxide and having a film thickness equal to or less than half that of the third electrode is formed on the second electrode. The method for manufacturing a semiconductor device according to claim 8.

Images