Signal transmission device

Abstract

To provide a signal transmission device for ensuring a dielectric voltage while restraining an increase in thickness between electrodes.SOLUTION: In a signal transmission device 5, a first lower electrode 31 has a lower-side first electrode end 315 located at the outer edge of a surface facing a first upper electrode 41 in a thickness direction DT. The first upper electrode 41 has an upper-side first electrode end 415 that is located outside the first upper electrode 41 in a direction perpendicular to the thickness direction DT and is in contact with a first insulating film 21. The lower-side first electrode end 315 is located inside the first upper electrode 41 with respect to the upper-side first electrode end 415 in the direction perpendicular to the thickness direction DT, and the distance Lub1 from the lower-side first electrode end 315 to the upper-side first electrode end 415 in the direction perpendicular to the thickness direction DT is 10 μm or more.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to signal transmission devices. [Background technology]

[0002] 2. Description of the Related Art As described in Patent Document 1, a capacitor is known that includes a lower electrode, an upper electrode, and an insulating film disposed between the lower electrode and the upper electrode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-33946 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a capacitor as described in Patent Document 1, the electric field strength between the lower electrode and the upper electrode may be reduced by increasing the thickness of the insulating film between the lower electrode and the upper electrode. This ensures the dielectric strength of the capacitor as a signal transmission device. However, increasing the thickness of the insulating film increases the number of manufacturing steps in the manufacture of the capacitor, such as the formation of a large number of vias and wiring layers. This increases the cost of the capacitor. Also, if the thickness of the insulating film is small, the electric field strength between the lower electrode and the upper electrode increases, and the dielectric strength of the capacitor is not ensured.

[0005] An object of the present disclosure is to provide a signal transmission device that ensures a high dielectric strength while suppressing an increase in the thickness between electrodes. [Means for solving the problem]

[0006] The invention described in claim 1 is a signal transmission device comprising a semiconductor substrate (7), an insulating film (21) having electrical insulation and formed on the semiconductor substrate, a first electrode (31, 32) covered by the insulating film, and a second electrode (41, 42) formed on the insulating film, facing the first electrode in a thickness direction (DT) of the semiconductor substrate, to which a voltage higher than a voltage applied to the first electrode is applied, wherein the first electrode has a first end (315, 325) located at an outer edge of a surface facing the second electrode in the thickness direction, the second electrode has a second end (415, 425) located outside the second electrode in a direction perpendicular to the thickness direction and in contact with the insulating film, the first end is located inside the second electrode relative to the second end in the direction perpendicular to the thickness direction, and a distance (Lub1, Lub2) from the first end to the second end in the direction perpendicular to the thickness direction is 10 μm or more.

[0007] As a result, the minimum distance from the second end to the first electrode is larger than when the distance from the first end to the second end is less than 10 μm. This reduces the electric field strength between the first electrode and the second electrode. Furthermore, it is not necessary to thicken the insulating film between the first electrode and the second electrode. This ensures the dielectric strength of the signal transmission device while suppressing an increase in the thickness between the electrodes.

[0008] The invention described in claim 2 is a signal transmission device comprising a semiconductor substrate (7), an insulating film (21) having electrical insulation and formed on the semiconductor substrate, a first electrode (31, 32) covered by the insulating film, and a second electrode (41, 42) formed on the insulating film, facing the first electrode in a thickness direction (DT) of the semiconductor substrate, and to which a voltage higher than that applied to the first electrode is applied, wherein the first electrode has an electrode end (315, 325) located at an outer edge of a surface facing the second electrode in the thickness direction, and the second electrode has a slit (417, 427) penetrating the second electrode in the thickness direction, and a slit end (419, 429) that is at the outer edge of a surface facing the outside of the second electrode in a direction perpendicular to the thickness direction among side surfaces forming the slit in the second electrode and is in contact with the insulating film, and the slit end is located outside the first electrode in the direction perpendicular to the thickness direction.

[0009] As a result, the minimum distance from the slit end to the first electrode becomes larger than when the slit end is located inside the electrode end in a direction perpendicular to the thickness direction. Therefore, the electric field strength between the slit end and the first electrode becomes smaller. Therefore, the electric field strength between the first electrode and the second electrode becomes relatively small. Furthermore, it is not necessary to thicken the insulating film between the first electrode and the second electrode. Therefore, the increase in the thickness between the electrodes is suppressed, and the dielectric strength of the signal transmission device is ensured.

[0010] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and specific components described in the embodiments described below. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a top view layout diagram of the signal transmission device according to the first embodiment. [Diagram 2] Cross-sectional view of line II-II in Figure 1. [Diagram 3] FIG. 2 is a diagram showing a first bottom electrode and a first lead-out wiring of the signal transmission device. [Figure 4] FIG. 13 is a diagram showing a second bottom electrode and a second lead-out wiring of the signal transmission device. [Diagram 5] FIG. 1 is a diagram showing an electric field distribution in a signal transmission device. [Figure 6] 1 is a diagram showing the relationship between the distance between the first ends of a signal transmission device and the maximum electric field strength. [Figure 7] 1 is a diagram showing the relationship between the distance between the first ends of a signal transmission device and the maximum electric field strength. [Figure 8] FIG. 1 is a diagram showing an electric field distribution in a signal transmission device. [Figure 9] FIG. 1 is a diagram showing an electric field distribution in a signal transmission device. [Figure 10] FIG. 1 is a diagram showing an electric field distribution in a signal transmission device. [Figure 11] FIG. 1 is a diagram showing an electric field distribution in a signal transmission device. [Figure 12] 1 is a diagram showing the relationship between the position in the thickness direction of a signal transmission device and maximum electric field intensity. [Figure 13] FIG. 13 is a relationship diagram between the first slit distance and the maximum electric field strength of a signal transmission device. [Figure 14] 1 is a relationship diagram of the first radius on the lower side of a signal transmission device and maximum electric field strength. [Figure 15] FIG. 1 is a diagram showing an electric field distribution in a signal transmission device. [Figure 16] FIG. 1 is a diagram showing an electric field distribution in a signal transmission device. [Figure 17] FIG. 1 is a diagram showing an electric field distribution in a signal transmission device. [Figure 18] FIG. 1 is a diagram showing an electric field distribution in a signal transmission device. [Figure 19] FIG. 1 is a diagram showing an electric field distribution in a signal transmission device. [Figure 20] FIG. 11 is a cross-sectional view of a signal transmission device according to a second embodiment. [Figure 21] FIG. 11 is a cross-sectional view of a signal transmission device according to a third embodiment. [Figure 22] FIG. 13 is a cross-sectional view of a signal transmission device according to a fourth embodiment. [Figure 23] FIG. 13 is a top view layout diagram of a signal transmission device according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals, and the description thereof will be omitted.

[0013] (First embodiment) In the signal transmission device of this embodiment, an increase in the thickness between the electrodes is suppressed, and the dielectric strength of the signal transmission device is ensured.

[0014] 1 and 2, the signal transmission device 5 includes a semiconductor substrate 7, an arithmetic circuit 10, a first insulating film 21, a first lower electrode 31, a first upper electrode 41, a shield part 50, and a first outgoing wiring 61. The signal transmission device 5 further includes a second lower electrode 32, a second upper electrode 42, a second outgoing wiring 62, a second insulating film 22, and a third insulating film 23.

[0015] The semiconductor substrate 7 is made of, for example, silicon etc. Hereinafter, the thickness direction DT of the semiconductor substrate 7 will be simply referred to as the thickness direction DT.

[0016] The arithmetic circuit 10 is, for example, a microcomputer or the like arranged on a semiconductor substrate 7, and is an electronic circuit that executes arithmetic operations and logical operations.

[0017] 2, the first insulating film 21 has electrical insulation properties and is formed on the semiconductor substrate 7. The first insulating film 21 has a first film 211, a second film 212, a third film 213, a fourth film 214, a fifth film 215, a sixth film 216, and a seventh film 217. Here, the first insulating film 21 has a seven-layer structure. In contrast, the number of layers of the first insulating film 21 is not limited to seven and is arbitrary.

[0018] The first film 211 is formed on the semiconductor substrate 7. The second film 212 is formed on the first film 211. The third film 213 is formed on the second film 212. The fourth film 214 is formed on the third film 213. The fifth film 215 is formed on the fourth film 214. The sixth film 216 is formed on the fifth film 215. The seventh film 217 is formed on the sixth film 216. Furthermore, the fifth film 215 is connected to the opposite side of the sixth film 216 to the seventh film 217 in the thickness direction DT, and is connected to the first lower electrode 31 and the second lower electrode 32 described later in the thickness direction DT via the second film 212, the third film 213, and the fourth film 214. Moreover, the sixth film 216 is connected to the opposite side of the seventh film 217 to the first upper electrode 41 and the second upper electrode 42 described later in the thickness direction DT. Furthermore, the seventh film 217 is connected to a first upper electrode 41 and a second upper electrode 42, which will be described later, in the thickness direction DT.

[0019] Moreover, the first film 211, the second film 212, the third film 213, the fourth film 214, the fifth film 215, and the seventh film 217 are formed of silicon dioxide or the like, and are therefore oxide films. Furthermore, the sixth film 216 is formed of silicon nitride or the like, and is therefore a nitride film.

[0020] The first lower electrode 31 is formed on the first film 211 and is thereby covered with the first insulating film 21. The first lower electrode 31 is made of a metal such as aluminum, tungsten, copper, titanium, or tantalum, and is therefore conductive. The length of the first lower electrode 31 in the thickness direction DT, i.e., the thickness of the first lower electrode 31, is, for example, 0.1 to 1.0 μm.

[0021] In addition, the cross section of first lower electrode 31 cut in a direction perpendicular to thickness direction DT is formed in an elliptical shape here. Therefore, first lower electrode 31 has lower-side first curved portion 311, lower-side second curved portion 312, and lower-side first straight portion 313, as shown in FIG.

[0022] The lower first curved portion 311 is curved convexly on the arithmetic circuit 10 side in a direction perpendicular to the thickness direction DT. As a result, the center of curvature of the lower first curved portion 311 is located inside the first lower electrode 31. Furthermore, since the first lower electrode 31 has an elliptical shape, the lower first curved portion 311 is formed in an arc shape. The lower first radius Rb1 is, for example, 20 μm or more. The lower first radius Rb1 is the radius of the lower first curved portion 311.

[0023] The lower second curved portion 312 is formed to be curved convexly on the opposite side to the arithmetic circuit 10 in the direction perpendicular to the thickness direction DT. Therefore, the center of curvature of the lower second curved portion 312 is located inside the first lower electrode 31. Furthermore, since the shape of the first lower electrode 31 is an ellipse, the lower second curved portion 312 is formed in an arc shape. Moreover, the lower second radius Rb2 is, for example, 20 μm or more. The lower second radius Rb2 is the radius of the lower second curved portion 312.

[0024] The lower first straight portion 313 is connected to the lower first curved portion 311 and the lower second curved portion 312. Furthermore, the lower first straight portion 313 extends in one direction perpendicular to the thickness direction DT. The lower first radius Rb1 and the lower second radius Rb2 are set to be half or less of the lower first width Wb1, that is, Rb1≦Wb1 / 2 and Rb2≦Wb1 / 2. The lower first width Wb1 is the length of the lower first straight portion 313 in a direction perpendicular to the thickness direction DT and the direction in which the lower first straight portion 313 extends.

[0025] 2, the first upper electrode 41 is formed on the seventh film 217, and thus on the first insulating film 21. The first upper electrode 41 is made of a metal such as aluminum, tungsten, copper, titanium, or tantalum, and thus has electrical conductivity. Furthermore, the length of the first upper electrode 41 in the thickness direction DT, i.e., the thickness of the first upper electrode 41, is, for example, 1.0 to 10.0 μm.

[0026] Moreover, a cross section of the first upper electrode 41 cut in a direction perpendicular to the thickness direction DT corresponds to the shape of the first lower electrode 31, and is formed in an elliptical shape here. Therefore, the first upper electrode 41 has an upper-side first curved portion 411, an upper-side second curved portion 412, and an upper-side first straight portion 413, as shown in FIG.

[0027] The upper first curved portion 411 is curved convexly on the arithmetic circuit 10 side in a direction perpendicular to the thickness direction DT. As a result, the center of curvature of the upper first curved portion 411 is located inside the first upper electrode 41. Furthermore, since the first upper electrode 41 has an elliptical shape, the upper first curved portion 411 is formed in an arc shape. The upper first radius Ru1 is, for example, 20 μm or more. The upper first radius Ru1 is the radius of the upper first curved portion 411.

[0028] The upper-side second curved portion 412 is curved convexly on the opposite side to the arithmetic circuit 10 in the direction perpendicular to the thickness direction DT. Therefore, the center of curvature of the upper-side second curved portion 412 is located inside the first upper electrode 41. Furthermore, since the first upper electrode 41 has an elliptical shape, the upper-side second curved portion 412 is formed in an arc shape. The upper-side second radius Ru2 is, for example, 20 μm or more. The upper-side second radius Ru2 is the radius of the upper-side second curved portion 412.

[0029] The upper-side first straight portion 413 is connected to the upper-side first curved portion 411 and the upper-side second curved portion 412. Furthermore, the upper-side first straight portion 413 extends in the same direction as the lower-side first straight portion 313 extends. Furthermore, the upper-side first radius Ru1 and the upper-side second radius Ru2 are set to be half or less of the upper-side first width Wu1, that is, Ru1≦Wu1 / 2, Ru2≦Wu1 / 2. Note that the upper-side first width Wu1 is the length of the upper-side first straight portion 413 in the direction perpendicular to the thickness direction DT and the direction in which the upper-side first straight portion 413 extends.

[0030] 2, the first upper electrode 41 faces the first lower electrode 31 in the thickness direction DT. Therefore, the first upper electrode 41 and the first lower electrode 31 form a capacitor. The first inter-electrode distance Lud1 is set to be 5.0 μm or more and 8.0 μm or less. The first inter-electrode distance Lud1 is the distance from the first upper electrode 41 to the first lower electrode 31 in the thickness direction DT.

[0031] Here, as shown in FIG. 1 and FIG. 2, the area of ​​the surface of the first lower electrode 31 perpendicular to the thickness direction DT is defined as the first lower area Sb1. Furthermore, the area of ​​the surface of the first upper electrode 41 perpendicular to the thickness direction DT is defined as the first upper area Su1. Furthermore, the end located on the outer edge of the surface of the first lower electrode 31 facing the first upper electrode 41 in the thickness direction DT is defined as the lower first electrode end 315. Furthermore, the end of the first upper electrode 41 located outside the first upper electrode 41 in the direction perpendicular to the thickness direction DT and in contact with the seventh film 217 is defined as the upper first electrode end 415. Furthermore, the minimum distance from the lower first electrode end 315 to the upper first electrode end 415 in the direction perpendicular to the thickness direction DT is defined as the first end distance Lub1.

[0032] The first upper area Su1 is larger than the first lower area Sb1, i.e., Su1>Sb1. Furthermore, the lower-side first electrode end 315 is located on the inner side of the first upper electrode 41 than the upper-side first electrode end 415 in the direction perpendicular to the thickness direction DT. The first end distance Lub1 is set to be 10 μm or more and 50 μm or less.

[0033] Furthermore, the first upper electrode 41 has a first slit 417 and a first slit end 419 .

[0034] The first slit 417 is a hole penetrating the first upper electrode 41 in the thickness direction DT. The cross section of the first slit 417 cut in a direction perpendicular to the thickness direction DT corresponds to the shape of the first upper electrode 41, and is formed in an elliptical shape here. In FIG. 1, the first slit 417 is shown in a dot pattern to clarify the location of the first slit 417.

[0035] 2, the first slit end 419 is an outer edge of a surface facing the outside of the first upper electrode 41 in a direction perpendicular to the thickness direction DT among the side surfaces forming the first slit 417 in the first upper electrode 41, and is in contact with the seventh film 217. Furthermore, the first slit end 419 is located outside the first lower electrode 31 more than the lower first electrode end 315 in a direction perpendicular to the thickness direction DT. In addition, the first slit distance Lsb1 is set to be 1.0 μm or more and 50 μm or less. Note that the first slit distance Lsb1 is the minimum distance from the first slit end 419 to the lower first electrode end 315 in a direction perpendicular to the thickness direction DT.

[0036] Further, here, the distance from the surface of the sixth film 216 on the first lower electrode 31 side in the thickness direction DT to the first lower electrode 31 is defined as a first lower distance Lb1. Also, the distance from the surface of the sixth film 216 on the first upper electrode 41 side in the thickness direction DT to the first upper electrode 41 is defined as a first upper distance Lu1.

[0037] The upper first distance Lu1 is smaller than the lower first distance Lb1. <Lb1とされている。

[0038] 1, a part of the shield section 50 is disposed between the first lower electrode 31 and the first upper electrode 41 and the arithmetic circuit 10 in a direction perpendicular to the thickness direction DT. The potential of the shield section 50 is set to a reference potential. As shown in FIG. 2, the shield section 50 further includes a first via 501, a first conductor 511, a second via 502, a second conductor 512, a third via 503, a third conductor 513, a fourth via 504, and a fourth conductor 514.

[0039] The first via 501 is formed by filling a via hole formed in the first film 211 with a metal such as tungsten by using CVD or the like. Note that CVD is an abbreviation for Chemical Vapor Deposition.

[0040] The first conductor 511 is connected to the first via 501 in the thickness direction DT. The first conductor 511 is formed together with the first lower electrode 31, and is made of a metal such as aluminum, tungsten, copper, titanium, or tantalum. The first conductor 511 is covered with the second film 212.

[0041] The second via 502 is formed by filling a via hole formed in the second film 212 with a metal such as tungsten by using CVD or the like. The second via 502 is connected to the first conductor 511 in the thickness direction DT.

[0042] The second conductor 512 is connected to the second via 502 in the thickness direction DT. The second conductor 512 is made of a metal such as aluminum, tungsten, copper, titanium, or tantalum. The second conductor 512 is covered with the third film 213.

[0043] The third via 503 is formed by filling a via hole formed in the third film 213 with a metal such as tungsten by using CVD or the like. Furthermore, the third via 503 is connected to the second conductor 512 in the thickness direction DT.

[0044] The third conductor 513 is connected to the third via 503 in the thickness direction DT. The third conductor 513 is made of a metal such as aluminum, tungsten, copper, titanium, or tantalum. The third conductor 513 is covered with the fourth film 214.

[0045] The fourth via 504 is formed by filling a via hole formed in the fourth film 214 with a metal such as tungsten by using CVD or the like. The fourth via 504 is connected to the third conductor 513 in the thickness direction DT.

[0046] The fourth conductor 514 is connected to the fourth via 504 in the thickness direction DT. Furthermore, the third conductor 513 is formed of a metal such as aluminum, tungsten, copper, titanium, or tantalum. Furthermore, the fourth conductor 514 is covered with the fifth film 215. Furthermore, as shown in FIG. 1, the fourth conductor 514 is formed in a rectangular ring shape, and thus surrounds the first lower electrode 31 and the first upper electrode 41 in a direction perpendicular to the thickness direction DT. Note that, although the shape of the fourth conductor 514 is a rectangular ring shape here, it is not limited thereto, and may be a polygonal ring shape, a circular ring shape, an oval ring shape, or the like.

[0047] The first extension wiring 61 is formed together with the first lower electrode 31. Furthermore, the first extension wiring 61 is made of a metal such as aluminum, tungsten, copper, titanium, or tantalum, and thus has electrical conductivity. The first extension wiring 61 also has a first connection portion 611, a first extension portion 612, and a second extension portion 613.

[0048] The first connection portion 611 is connected to the first lower electrode 31, and here, is connected to the lower-side first curved portion 311. Note that the first connection portion 611 is not limited to being connected to the lower-side first curved portion 311, and may be connected to the lower-side second curved portion 312 and the lower-side first straight portion 313.

[0049] 3, the outer edge of the cross section of the first connecting portion 611 when cut in a direction perpendicular to the thickness direction DT is formed into a concavely curved shape. Therefore, the center of curvature of the first connecting portion 611 is located outside the first connecting portion 611. The radius of curvature of the first connecting portion 611 is set to, for example, 10 μm. Furthermore, the first length L1 becomes shorter from the first connecting portion 611 toward the first extending portion 612 described below. The first length L1 is the length of the first connecting portion 611 in a direction perpendicular to the thickness direction DT and the direction in which the first extending portion 612 extends.

[0050] The first extension portion 612 is connected to the side of the first connection portion 611 opposite to the first lower electrode 31. The first extension portion 612 extends in a direction intersecting with the first shortest direction Dmin1. The first shortest direction Dmin1 is the shortest direction of a line segment connecting the first connection portion 611 and the shield portion 50 in a direction perpendicular to the thickness direction DT. Furthermore, although the first extension portion 612 extends linearly here, it is not limited to this and may extend in a curved manner.

[0051] Here, a first angle θ1 is defined as an angle formed by a line extending in the first shortest direction Dmin1 and a line extending in the direction in which the first extension portion 612 extends. The first angle θ1 is set to be equal to or greater than 45° and less than 90°.

[0052] 1, the second extension portion 613 is connected to the side of the first extension portion 612 opposite to the first connection portion 611. Furthermore, the second extension portion 613 extends in a direction intersecting the direction in which the first extension portion 612 extends, for example, in the first shortest direction Dmin1. As a result, the second extension portion 613 is connected to the arithmetic circuit 10. Note that, although the second extension portion 613 extends linearly here, it is not limited thereto and may extend in a curved line.

[0053] 2, the second lower electrode 32 is formed on the first film 211 and is thereby covered with the first insulating film 21. In addition, the second lower electrode 32 is formed of a metal such as aluminum, tungsten, copper, titanium, or tantalum, and is therefore conductive. Furthermore, the length of the second lower electrode 32 in the thickness direction DT, that is, the thickness of the second lower electrode 32, is set to, for example, 0.1 to 1.0 μm.

[0054] In addition, the cross section of second lower electrode 32 cut in a direction perpendicular to thickness direction DT is formed in an elliptical shape here. Therefore, second lower electrode 32 has lower-side third curved portion 321, lower-side fourth curved portion 322, and lower-side second straight portion 323, as shown in FIG.

[0055] The lower-side third curved portion 321 is curved convexly on the arithmetic circuit 10 side in a direction perpendicular to the thickness direction DT. As a result, the center of curvature of the lower-side third curved portion 321 is located inside the second lower electrode 32. Furthermore, since the second lower electrode 32 has an elliptical shape, the lower-side third curved portion 321 is formed in an arc shape. The lower-side third radius Rb3 is, for example, 20 μm or more. The lower-side third radius Rb3 is the radius of the lower-side third curved portion 321.

[0056] The lower-side fourth curved portion 322 is curved convexly on the side opposite to the arithmetic circuit 10 in the direction perpendicular to the thickness direction DT. Therefore, the center of curvature of the lower-side fourth curved portion 322 is located inside the second lower electrode 32. Furthermore, since the second lower electrode 32 has an elliptical shape, the lower-side fourth curved portion 322 is formed in an arc shape. The lower-side fourth radius Rb4 is, for example, 20 μm or more. The lower-side fourth radius Rb4 is the radius of the lower-side fourth curved portion 322.

[0057] The lower-side second straight portion 323 is connected to the lower-side third curved portion 321 and the lower-side fourth curved portion 322. Furthermore, the lower-side second straight portion 323 extends in the same direction as the lower-side first straight portion 313 extends. In addition, the lower-side third radius Rb3 and the lower-side fourth radius Rb4 are set to be half or less of the lower-side second width Wb2, that is, Rb3≦Wb2 / 2 and Rb4≦Wb2 / 2. The lower-side second width Wb2 is the length of the lower-side second straight portion 323 in the direction perpendicular to the thickness direction DT and the direction in which the lower-side second straight portion 323 extends.

[0058] Furthermore, the second lower electrode 32 is aligned with the first lower electrode 31 in a direction perpendicular to the thickness direction DT. The second lower electrode 32 is surrounded by the shield part 50 in a direction perpendicular to the thickness direction DT.

[0059] 2, the second upper electrode 42 is formed on the seventh film 217, and thereby formed on the first insulating film 21. The second upper electrode 42 is made of a metal such as aluminum, tungsten, copper, titanium, or tantalum, and thus has electrical conductivity. Furthermore, the length of the second upper electrode 42 in the thickness direction DT, i.e., the thickness of the second upper electrode 42, is, for example, 1.0 to 10.0 μm.

[0060] Moreover, the cross section of the second upper electrode 42 cut in a direction perpendicular to the thickness direction DT corresponds to the shape of the second lower electrode 32, and is formed in an elliptical shape here. Therefore, the second upper electrode 42 has an upper-side third curved portion 421, an upper-side fourth curved portion 422, and an upper-side second straight portion 423, as shown in FIG.

[0061] The upper-side third curved portion 421 is curved convexly on the arithmetic circuit 10 side in a direction perpendicular to the thickness direction DT. As a result, the center of curvature of the upper-side third curved portion 421 is located inside the second upper electrode 42. Furthermore, since the second upper electrode 42 has an elliptical shape, the upper-side third curved portion 421 is formed in an arc shape. The upper-side third radius Ru3 is, for example, 20 μm or more. The upper-side third radius Ru3 is the radius of the upper-side third curved portion 421.

[0062] The upper-side fourth curved portion 422 is curved convexly on the opposite side to the arithmetic circuit 10 in the direction perpendicular to the thickness direction DT. Therefore, the center of curvature of the upper-side fourth curved portion 422 is located inside the second upper electrode 42. Furthermore, since the second upper electrode 42 has an elliptical shape, the upper-side fourth curved portion 422 is formed in an arc shape. The upper-side fourth radius Ru4 is, for example, 20 μm or more. The upper-side fourth radius Ru4 is the radius of the upper-side fourth curved portion 422.

[0063] The upper-side second straight portion 423 is connected to the upper-side third curved portion 421 and the upper-side fourth curved portion 422. Furthermore, the upper-side second straight portion 423 extends in the direction in which the lower-side second straight portion 323 extends. In addition, the upper-side third radius Ru3 and the upper-side fourth radius Ru4 are set to be half or less of the upper-side second width Wu2, that is, Ru3≦Wu2 / 2, Ru4≦Wu2 / 2. Note that the upper-side second width Wu2 is the length of the upper-side second straight portion 423 in a direction perpendicular to the thickness direction DT and the direction in which the upper-side second straight portion 423 extends.

[0064] 2, the second upper electrode 42 faces the second lower electrode 32 in the thickness direction DT. Therefore, the second upper electrode 42 and the second lower electrode 32 form a capacitor. The second inter-electrode distance Lud2 is set to be 5.0 μm or more and 8.0 μm or less. The second inter-electrode distance Lud2 is the distance from the second upper electrode 42 to the second lower electrode 32 in the thickness direction DT.

[0065] Furthermore, the second upper electrode 42 is aligned with the first upper electrode 41 in a direction perpendicular to the thickness direction DT. As shown in Fig. 1, the second upper electrode 42 is surrounded by a shield section 50 in a direction perpendicular to the thickness direction DT. Furthermore, a part of the shield section 50 is disposed between the second lower electrode 32 and the second upper electrode 42 and the arithmetic circuit 10 in the direction perpendicular to the thickness direction DT.

[0066] Here, as shown in FIG. 1 and FIG. 2, the area of ​​the surface of the second lower electrode 32 perpendicular to the thickness direction DT is defined as the second lower area Sb2. Furthermore, the area of ​​the surface of the second upper electrode 42 perpendicular to the thickness direction DT is defined as the second upper area Su2. Furthermore, the end located on the outer edge of the surface of the second lower electrode 32 facing the second upper electrode 42 in the thickness direction DT is defined as the lower second electrode end 325. Furthermore, the end of the second upper electrode 42 located outside the second upper electrode 42 in the direction perpendicular to the thickness direction DT and in contact with the seventh film 217 is defined as the upper second electrode end 425. Furthermore, the minimum distance from the lower second electrode end 325 to the upper second electrode end 425 in the direction perpendicular to the thickness direction DT is defined as the second end distance Lub2.

[0067] The second upper area Su2 is larger than the second lower area Sb2, i.e., Su2>Sb2. Furthermore, the lower second electrode end 325 is located on the inner side of the second upper electrode 42 than the upper second electrode end 425 in the direction perpendicular to the thickness direction DT. The second end distance Lub2 is 10 μm or more and 50 μm or less.

[0068] Furthermore, the second upper electrode 42 has a second slit 427 and a second slit end 429 .

[0069] The second slit 427 is a hole that penetrates the second upper electrode 42 in the thickness direction DT. Further, the cross-section when the second slit 427 is cut in a direction orthogonal to the thickness direction DT corresponds to the shape of the second upper electrode 42, and here, it is formed in an oval shape. In FIG. 1, in order to clarify the location of the second slit 427, the second slit 427 is shown as a dotted pattern.

[0070] As shown in FIG. 2, the second slit end 429 is the outer edge of the surface facing the outside of the second upper electrode 42 in the direction orthogonal to the thickness direction DT among the side surfaces of the second upper electrode 42 where the second slit 427 is formed, and is in contact with the seventh film 217. Further, the second slit end 429 is located outside the second lower electrode 32 rather than the lower-side second electrode end 325 in the direction orthogonal to the thickness direction DT. Also, the second slit distance Lsb2 is set to be 1.0 μm or more and 50 μm or less. The second slit distance Lsb2 is the minimum distance from the second slit end 429 to the lower-side second electrode end 325 in the direction orthogonal to the thickness direction DT.

[0071] Furthermore, here, the distance from the surface of the sixth film 216 on the second lower electrode 32 side to the second lower electrode 32 in the thickness direction DT is defined as the lower-side second distance Lb2. Also, the distance from the surface of the sixth film 216 on the second upper electrode 42 side to the second upper electrode 42 in the thickness direction DT is defined as the upper-side second distance Lu2.

[0072] And the upper-side second distance Lu2 is smaller than the lower-side second distance Lb2, that is, Lu2 < Lb2. Further, the upper-side second distance Lu2 is set to be the same as the upper-side first distance Lu1, that is, Lu1 = Lu2. Also, the lower-side second distance Lb2 is set to be the same as the lower-side first distance Lb1, that is, Lb1 = Lb2. Here, "the same" includes the manufacturing error range.

[0073] 1, the second extension wiring 62 is formed together with the first lower electrode 31, the first extension wiring 61, and the second lower electrode 32. Furthermore, the second extension wiring 62 is made of a metal such as aluminum, tungsten, copper, titanium, or tantalum, and thus has electrical conductivity. The second extension wiring 62 also has a second connection portion 621, a third extension portion 622, and a fourth extension portion 623.

[0074] The second connection portion 621 is connected to the second lower electrode 32, and here, is connected to the lower-side third curved portion 321. Note that the second connection portion 621 is not limited to being connected to the lower-side third curved portion 321, and may be connected to the lower-side fourth curved portion 322 and the lower-side second straight portion 323.

[0075] 4, the outer edge of the cross section of the second connecting portion 621 when cut in a direction perpendicular to the thickness direction DT is formed into a concavely curved shape. Therefore, the center of curvature of the second connecting portion 621 is located outside the second connecting portion 621. The radius of curvature of the second connecting portion 621 is, for example, 10 μm. Furthermore, the second length L2 becomes shorter from the second connecting portion 621 toward the third extending portion 622 described below. The second length L2 is the length of the second connecting portion 621 in a direction perpendicular to the thickness direction DT and the direction in which the third extending portion 622 extends.

[0076] The third extension portion 622 is connected to the side of the second connection portion 621 opposite to the second lower electrode 32. The third extension portion 622 extends in a direction intersecting with the second shortest direction Dmin2. The second shortest direction Dmin2 is the shortest direction of a line segment connecting the second connection portion 621 and the shield portion 50 in a direction perpendicular to the thickness direction DT. Further, although the third extension portion 622 extends linearly here, it is not limited to this and may extend in a curved manner.

[0077] Here, the angle between a line extending in the second shortest direction Dmin2 and a line extending in the direction in which the third extension portion 622 extends is defined as a second angle θ2. The second angle θ2 is set to be equal to or greater than 45° and less than 90°.

[0078] 1, the fourth extension portion 623 is connected to the side of the third extension portion 622 opposite to the second connection portion 621. Furthermore, the fourth extension portion 623 extends in a direction intersecting the direction in which the third extension portion 622 extends, for example, in the second shortest direction Dmin2. This allows the fourth extension portion 623 to be connected to the arithmetic circuit 10. Note that, although the fourth extension portion 623 extends linearly here, it is not limited thereto and may extend in a curved line.

[0079] The direction in which the first lower electrode 31 and the second lower electrode 32 are arranged is defined as a parallel direction Dp. The first extension 612 and the third extension 622 face each other in the parallel direction Dp. The second extension 613 and the fourth extension 623 face each other in the parallel direction Dp.

[0080] Returning to FIG. 2, the second insulating film 22 is formed of, for example, silicon dioxide or the like, and thus has electrical insulation properties. The second insulating film 22 covers the outer periphery of the first upper electrode 41 and also covers the periphery of the outer periphery of the first upper electrode 41 in the seventh film 217. The second insulating film 22 covers the outer periphery of the second upper electrode 42 and also covers the periphery of the outer periphery of the second upper electrode 42 in the seventh film 217. After a film covering the first upper electrode 41 and the second upper electrode 42 is formed by, for example, CVD or the like, the film is thinned and flattened by CMP or the like. Then, a part of the first upper electrode 41 and the second upper electrode 42 is exposed by etching. For this reason, an opening is formed in the second insulating film 22. Note that CMP is an abbreviation for Chemical Mechanical Polishing.

[0081] The third insulating film 23 has electrical insulation properties because it is made of, for example, polyimide etc. Furthermore, the third insulating film 23 has a lower dielectric strength than the second insulating film 22.

[0082] Moreover, the third insulating film 23 covers the outer periphery of the first upper electrode 41 and fills the first slit 417. Furthermore, the third insulating film 23 covers the outer periphery of the second upper electrode 42 and fills the second slit 427. As a result, the expansion and contraction of the third insulating film 23 caused by a temperature change of the signal transmission device 5 is less likely to be restricted compared to a case where the first slit 417 and the second slit 427 are not filled with the third insulating film 23. Therefore, the thermal stress applied to the third insulating film 23 is alleviated, and the stress applied to the second insulating film 22 covered by the third insulating film 23 is alleviated.

[0083] The third insulating film 23 covers the second insulating film 22 and also covers the seventh film 217. After the third insulating film 23 is formed by coating or the like, it is formed into a predetermined pattern shape by patterning or the like. As a result, parts of the first upper electrode 41 and the second upper electrode 42 are exposed. For this reason, openings are formed in the third insulating film 23.

[0084] The signal transmission device 5 is configured as described above. Next, the operation of the signal transmission device 5 will be described.

[0085] In the signal transmission device 5, a voltage higher than that applied to the first lower electrode 31 is applied to the first upper electrode 41. A signal from the arithmetic circuit 10 is transmitted to an external device via the second extension 613, the first extension 612, the first connection 611, the first lower electrode 31, the first upper electrode 41, and a bonding wire (not shown) connected to the first upper electrode 41. A voltage higher than that applied to the second lower electrode 32 is applied to the second upper electrode 42. A signal from the arithmetic circuit 10 is transmitted to an external device via the fourth extension 623, the third extension 622, the second connection 621, and a bonding wire (not shown) connected to the second lower electrode 32, the second upper electrode 42, and the second upper electrode 42. The external device is, for example, an external chip or the like equipped with a drive circuit (not shown). In this case, for example, the drive circuit turns on and off a power switching element (not shown) based on a signal from the arithmetic circuit 10. This drives, for example, a motor or the like.

[0086] The signal transmission device 5 operates as described above. Next, it will be described how the signal transmission device 5 ensures the dielectric strength while suppressing an increase in the thickness between the electrodes.

[0087] Here, if the upper first electrode end 415 is located outside the lower first electrode end 315 in the direction perpendicular to the thickness direction DT, the minimum distance from the upper first electrode end 415 to the first lower electrode 31 becomes relatively small. Therefore, as shown in FIG. 5, when a voltage higher than the voltage applied to the first lower electrode 31 is applied to the first upper electrode 41, the electric field strength between the first upper electrode 41 and the first lower electrode 31 becomes relatively large. Therefore, if the upper first electrode end 415 is located outside the lower first electrode end 315 in the direction perpendicular to the thickness direction DT, it is difficult to ensure the dielectric strength of the signal transmission device 5. Note that FIG. 5 is a diagram showing an electric field distribution when a voltage of 2250 V is applied between the first lower electrode 31 and the first upper electrode 41.

[0088] In contrast, in the signal transmission device 5 of the present embodiment, as shown in FIG. 2, the lower side first electrode end 315 of the first lower electrode 31 is located inside the first upper electrode 41 in the direction perpendicular to the thickness direction DT, relative to the upper side first electrode end 415 of the first upper electrode 41. The first end-to-end distance Lub1 is set to 10 μm or more. The first lower electrode 31 corresponds to the first electrode. The first upper electrode 41 corresponds to the second electrode. The lower side first electrode end 315 corresponds to the first end. The upper side first electrode end 415 corresponds to the second end. The first end-to-end distance Lub1 is the minimum distance from the lower side first electrode end 315 to the upper side first electrode end 415 in the direction perpendicular to the thickness direction DT, and corresponds to the distance from the first end to the second end in the direction perpendicular to the thickness direction DT.

[0089] As a result, the minimum distance from the upper first electrode end 415 to the first lower electrode 31 becomes larger compared to the case where the lower first electrode end 315 is positioned outside the upper first electrode end 415 in the direction perpendicular to the thickness direction DT. Therefore, the electric field strength between the first upper electrode 41 and the first lower electrode 31 becomes smaller.

[0090] 6 to 8, when the first end-to-end distance Lub1 is less than 10 μm, the maximum electric field strength of the signal transmission device 5 is relatively large. FIG. 6 is a diagram showing the relationship between the maximum electric field strength of the signal transmission device 5 and the first end-to-end distance Lub1 when a voltage of 2250 V is applied between the first lower electrode 31 and the first upper electrode 41. FIG. 7 is a diagram showing the relationship between the maximum electric field strength of the signal transmission device 5 and the first end-to-end distance Lub1 when the third insulating film 23 is not formed and a voltage of 2250 V is applied between the first lower electrode 31 and the first upper electrode 41. FIG. 8 is a diagram showing the electric field distribution when a voltage of 2250 V is applied between the first lower electrode 31 and the first upper electrode 41 and the first end-to-end distance Lub1 is 3 μm.

[0091] On the other hand, by setting the first end-to-end distance Lub1 to 10 μm or more, the maximum electric field strength of the signal transmission device 5 is smaller than when the first end-to-end distance Lub1 is less than 10 μm, as shown in FIG. 6, FIG. 7, and FIG. 9. Furthermore, when the first end-to-end distance Lub1 is 10 μm or more, the maximum electric field strength of the signal transmission device 5 gradually approaches the minimum value as the first end-to-end distance Lub1 increases. Therefore, by setting the first end-to-end distance Lub1 to 10 μm or more, the electric field strength between the first upper electrode 41 and the first lower electrode 31 becomes relatively small. Furthermore, it is not necessary to thicken the first insulating film 21 between the first upper electrode 41 and the first lower electrode 31. Therefore, the increase in the thickness between the electrodes is suppressed, and the dielectric strength of the signal transmission device 5 is ensured. 9 is a diagram showing the electric field distribution when a voltage of 2250 V is applied between the first lower electrode 31 and the first upper electrode 41 and the first end-to-end distance Lub1 is 15 μm. When the first end-to-end distance Lub1 is greater than 50 μm, the maximum electric field strength of the signal transmission device 5 is approximately the same as when the first end-to-end distance Lub1 is 50 μm. For this reason, it is preferable that the first end-to-end distance Lub1 is 50 μm or less.

[0092] In addition, the lower second electrode end 325 of the second lower electrode 32 is located inside the second upper electrode 42 in the direction perpendicular to the thickness direction DT, relative to the upper second electrode end 425 of the second upper electrode 42. In addition, the second end distance Lub2 is set to be 10 μm or more. The second lower electrode 32 corresponds to the first electrode. The second upper electrode 42 corresponds to the second electrode. The lower second electrode end 325 corresponds to the first end. The upper second electrode end 425 corresponds to the second end. The second end distance Lub2 is the minimum distance from the lower second electrode end 325 to the upper second electrode end 425 in the direction perpendicular to the thickness direction DT, and corresponds to the distance from the first end to the second end in the direction perpendicular to the thickness direction DT.

[0093] As a result, similar to the above, the electric field strength between the second upper electrode 42 and the second lower electrode 32 becomes relatively small, and there is no need to thicken the first insulating film 21 between the second upper electrode 42 and the second lower electrode 32. This ensures the dielectric strength of the signal transmission device 5 while suppressing an increase in the thickness between the electrodes. Note that, similar to the above, when the second end-to-end distance Lub2 is greater than 50 μm, the maximum electric field strength of the signal transmission device 5 becomes approximately the same as when the second end-to-end distance Lub2 is 50 μm. For this reason, it is preferable that the second end-to-end distance Lub2 is 50 μm or less.

[0094] Furthermore, the signal transmission device 5 of the first embodiment also provides the following advantages.

[0095] [1-1] The first upper electrode 41 has a first slit 417 and a first slit end 419. The first slit 417 penetrates the first upper electrode 41 in the thickness direction DT. The first slit end 419 is an outer edge of a surface facing the outside of the first upper electrode 41 in a direction perpendicular to the thickness direction DT among the side surfaces forming the first slit 417 in the first upper electrode 41, and is in contact with the first insulating film 21. In addition, the first slit end 419 is located outside the first lower electrode 31 in the direction perpendicular to the thickness direction DT, relative to the lower first electrode end 315. In addition, the lower first electrode end 315 corresponds to an electrode end.

[0096] As a result, the minimum distance from the first slit end 419 to the first lower electrode 31 becomes larger compared to when the first slit end 419 is located inside the lower first electrode end 315 in the direction perpendicular to the thickness direction DT. Therefore, as shown in FIG. 10 to FIG. 12, the electric field strength between the first slit end 419 and the first lower electrode 31 is smaller compared to when the first slit end 419 is located inside the lower first electrode end 315 in the direction perpendicular to the thickness direction DT. Therefore, when the first slit end 419 is located outside the first lower electrode 31 more than the lower first electrode end 315 in the direction perpendicular to the thickness direction DT, the electric field strength between the first upper electrode 41 and the first lower electrode 31 tends to become smaller. Furthermore, it is not necessary to thicken the first insulating film 21 between the first upper electrode 41 and the first lower electrode 31. Therefore, the increase in the thickness between the electrodes is suppressed, and the dielectric strength of the signal transmission device 5 is ensured.

[0097] The second upper electrode 42 has a second slit 427 and a second slit end 429. The second slit 427 penetrates the second upper electrode 42 in the thickness direction DT. The second slit end 429 is an outer edge of a surface facing the outside of the second upper electrode 42 in a direction perpendicular to the thickness direction DT among the side surfaces forming the second slit 427 in the second upper electrode 42, and is in contact with the first insulating film 21. The second slit end 429 is located outside the second lower electrode 32 further than the lower second electrode end 325 in the direction perpendicular to the thickness direction DT. The lower second electrode end 325 corresponds to an electrode end.

[0098] This, similarly to the above, tends to reduce the electric field strength between the second upper electrode 42 and the second lower electrode 32. Furthermore, it is not necessary to thicken the first insulating film 21 between the second upper electrode 42 and the second lower electrode 32. Thus, the withstand voltage of the signal transmission device 5 is ensured while suppressing an increase in the thickness between the electrodes.

[0099] [1-2] Here, as shown in FIG. 13, when the first slit distance Lsb1 is less than 1.0 μm, the maximum electric field intensity of the signal transmission device 5 is relatively large. The first slit distance Lsb1 is the minimum distance from the first slit end 419 to the lower side first electrode end 315 in the direction perpendicular to the thickness direction DT, and corresponds to the distance from the slit end to the electrode end in the direction perpendicular to the thickness direction DT. In addition, in FIG. 13, the first slit distance Lsb1 is set to a positive value when the first slit end 419 is located on the outer side of the first lower electrode 31 than the lower side first electrode end 315 in the direction perpendicular to the thickness direction DT. Furthermore, the first slit distance Lsb1 is set to a negative value when the first slit end 419 is located on the inner side of the first lower electrode 31 than the lower side first electrode end 315 in the direction perpendicular to the thickness direction DT.

[0100] In contrast, the first slit distance Lsb1 is set to 1.0 μm or more.

[0101] As a result, the maximum electric field strength of the signal transmission device 5 is smaller than when the first slit distance Lsb1 is less than 1.0 μm. Moreover, when the first slit distance Lsb1 is 1.0 μm or more, the maximum electric field strength of the signal transmission device 5 is rapidly reduced as the first slit distance Lsb1 is large. Therefore, when the first slit distance Lsb1 is 1.0 μm or more, the electric field strength between the first upper electrode 41 and the first lower electrode 31 is likely to be small. Furthermore, it is not necessary to thicken the first insulating film 21 between the first upper electrode 41 and the first lower electrode 31. Therefore, the insulation withstand voltage of the signal transmission device 5 is ensured while suppressing an increase in the thickness between the electrodes. Note that, when the first slit distance Lsb1 is greater than 50 μm, the maximum electric field strength of the signal transmission device 5 is almost the same as when the first slit distance Lsb1 is 50 μm. For this reason, it is preferable that the first slit distance Lsb1 is 50 μm or less.

[0102] The second slit distance Lsb2 is set to 1.0 μm or more. The second slit distance Lsb2 is the minimum distance from the second slit end 429 to the lower second electrode end 325 in the direction perpendicular to the thickness direction DT, and corresponds to the distance from the slit end to the electrode end in the direction perpendicular to the thickness direction DT.

[0103] As a result, the electric field strength between the second upper electrode 42 and the second lower electrode 32 tends to be small, as described above. Furthermore, it is not necessary to thicken the first insulating film 21 between the second upper electrode 42 and the second lower electrode 32. This ensures the dielectric strength of the signal transmission device 5 while suppressing an increase in the thickness between the electrodes. As described above, when the second slit distance Lsb2 is greater than 50 μm, the maximum electric field strength of the signal transmission device 5 is approximately the same as when the second slit distance Lsb2 is 50 μm. For this reason, it is preferable that the second slit distance Lsb2 is 50 μm or less.

[0104] [1-3] Here, when the first inter-electrode distance Lud1 is relatively small, the electric field strength between the first upper electrode 41 and the first lower electrode 31 increases, and the dielectric strength of the signal transmission device 5 decreases. When the first inter-electrode distance Lud1 is relatively large, the capacitance between the first lower electrode 31 and the first upper electrode 41 decreases, and the capacitance of the signal transmission device 5 decreases.

[0105] In contrast, in the signal transmission device 5, the first inter-electrode distance Lud1 is not less than 5.0 μm and not more than 8.0 μm. The first inter-electrode distance Lud1 is the distance from the first upper electrode 41 to the first lower electrode 31 in the thickness direction DT.

[0106] This prevents the first inter-electrode distance Lud1 from being excessively small or large, compared with the case where the first inter-electrode distance Lud1 is less than 5.0 μm or greater than 8.0 μm, and therefore ensures both the dielectric strength and capacitance of the signal transmission device 5.

[0107] Furthermore, in the signal transmission device 5, the second inter-electrode distance Lud2 is set to be not less than 5.0 μm and not more than 8.0 μm. The second inter-electrode distance Lud2 is the distance from the second upper electrode 42 to the second lower electrode 32 in the thickness direction DT.

[0108] This prevents the second inter-electrode distance Lud2 from being excessively small or large, compared with the case where the second inter-electrode distance Lud2 is less than 5.0 μm or more than 8.0 μm, and therefore ensures both the dielectric strength voltage and the capacitance of the signal transmission device 5.

[0109] [1-4] The first lower electrode 31 has a lower-side first curved portion 311 and a lower-side second curved portion 312. The lower-side first curved portion 311 and the lower-side second curved portion 312 are formed to be curved convexly in a direction perpendicular to the thickness direction DT.

[0110] This suppresses electric field concentration near the first lower electrode 31 compared to when the first lower electrode 31 does not have the lower side first curved portion 311 and the lower side second curved portion 312, for example, when the corners of the first lower electrode 31 are right angles.

[0111] The first upper electrode 41 has an upper-side first curved portion 411 and an upper-side second curved portion 412. The upper-side first curved portion 411 and the upper-side second curved portion 412 are formed to be curved convexly in a direction perpendicular to the thickness direction DT.

[0112] The second lower electrode 32 has a lower-side third curved portion 321 and a lower-side fourth curved portion 322. The lower-side third curved portion 321 and the lower-side fourth curved portion 322 are formed to be curved convexly in a direction perpendicular to the thickness direction DT.

[0113] The second upper electrode 42 has an upper-side third curved portion 421 and an upper-side fourth curved portion 422. The upper-side third curved portion 421 and the upper-side fourth curved portion 422 are formed to be curved convexly in a direction perpendicular to the thickness direction DT.

[0114] As a result, similarly to the above, electric field concentration near the first upper electrode 41, the second lower electrode 32, and the second upper electrode 42 is suppressed.

[0115] [1-5] The first lower electrode 31 is formed in an elliptical shape, so that the lower side first curved portion 311 and the lower side second curved portion 312 are formed in an arc shape. The first lower electrode 31 also has a lower side first straight portion 313. The lower side first straight portion 313 is connected to the lower side first curved portion 311 and the lower side second curved portion 312, and extends in one direction perpendicular to the thickness direction DT. Furthermore, the lower side first radius Rb1 is set to be 20 μm or more and half or less of the lower side first width Wb1. Furthermore, the lower side second radius Rb2 is set to be 20 μm or more and half or less of the lower side first width Wb1. The lower side first radius Rb1 is the radius of the lower side first curved portion 311. Furthermore, the lower side second radius Rb2 is the radius of the lower side second curved portion 312. Moreover, the lower first width Wb1 is the length of the lower first straight portion 313 in a direction perpendicular to the thickness direction DT and the direction in which the lower first straight portion 313 extends.

[0116] 14, when the lower first radius Rb1 is less than 20 μm, the change in maximum electric field strength of the signal transmission device 5 with the change in the lower first radius Rb1 is zero. When the lower first radius Rb1 is 20 μm or more, the occurrence of electric field concentration near the first lower electrode 31 is suppressed, and therefore the maximum electric field strength of the signal transmission device 5 decreases with an increase in the lower first radius Rb1. Furthermore, there is no need to thicken the first insulating film 21 between the first upper electrode 41 and the first lower electrode 31. Therefore, the dielectric strength of the signal transmission device 5 is ensured while suppressing an increase in the thickness between the electrodes.

[0117] Furthermore, when the lower side second radius Rb2 is 20 μm or more, as described above, electric field concentration near the first lower electrode 31 is suppressed, and therefore the dielectric strength of the signal transmission device 5 is ensured while suppressing an increase in the thickness between the electrodes.

[0118] Moreover, the first upper electrode 41 is formed in an elliptical shape, so that the upper side first curved portion 411 and the upper side second curved portion 412 are formed in an arc shape. Furthermore, the first upper electrode 41 has an upper side first straight portion 413. The upper side first straight portion 413 is connected to the upper side first curved portion 411 and the upper side second curved portion 412, and extends in one direction perpendicular to the thickness direction DT. Furthermore, the upper side first radius Ru1 is set to be 20 μm or more and half or less of the upper side first width Wu1. Furthermore, the upper side second radius Ru2 is set to be 20 μm or more and half or less of the upper side first width Wu1. Note that the upper side first radius Ru1 is the radius of the upper side first curved portion 411. Furthermore, the upper side second radius Ru2 is the radius of the upper side second curved portion 412. Furthermore, the upper-side first width Wu1 is the length of the upper-side first straight portion 413 in a direction perpendicular to the thickness direction DT and the direction in which the upper-side first straight portion 413 extends.

[0119] Moreover, the second lower electrode 32 is formed in an elliptical shape, so that the lower side third curved portion 321 and the lower side fourth curved portion 322 are formed in an arc shape. Furthermore, the second lower electrode 32 has a lower side second straight portion 323. The lower side second straight portion 323 is connected to the lower side third curved portion 321 and the lower side fourth curved portion 322, and extends in one direction perpendicular to the thickness direction DT. Furthermore, the lower side third radius Rb3 is set to be 20 μm or more and half or less of the lower side second width Wb2. Furthermore, the lower side fourth radius Rb4 is set to be 20 μm or more and half or less of the lower side second width Wb2. The lower side third radius Rb3 is the radius of the lower side third curved portion 321. Furthermore, the lower side fourth radius Rb4 is the radius of the lower side fourth curved portion 322. Furthermore, the second lower width Wb2 is the length of the second lower straight portion 323 in a direction perpendicular to the thickness direction DT and the direction in which the second lower straight portion 323 extends.

[0120] Moreover, the second upper electrode 42 is formed in an elliptical shape, so that the upper side third curved portion 421 and the upper side fourth curved portion 422 are formed in an arc shape. Furthermore, the second upper electrode 42 has an upper side second straight portion 423. The upper side second straight portion 423 is connected to the upper side third curved portion 421 and the upper side fourth curved portion 422, and extends in one direction perpendicular to the thickness direction DT. Furthermore, the upper side third radius Ru3 is set to be 20 μm or more and half or less of the upper side second width Wu2. Furthermore, the upper side fourth radius Ru4 is set to be 20 μm or more and half or less of the upper side second width Wu2. The upper side third radius Ru3 is the radius of the upper side third curved portion 421. Furthermore, the upper side fourth radius Ru4 is the radius of the upper side fourth curved portion 422. Furthermore, the upper-side second width Wu2 is the length of the upper-side second straight portion 423 in a direction perpendicular to the thickness direction DT and the direction in which the upper-side second straight portion 423 extends.

[0121] As a result, similar to the above, electric field concentration near the first upper electrode 41, the second lower electrode 32 and the second upper electrode 42 is suppressed, thereby ensuring the dielectric strength of the signal transmission device 5 while suppressing an increase in the thickness between the electrodes.

[0122] [1-6] The first insulating film 21 has a fifth film 215, a sixth film 216, and a seventh film 217. The fifth film 215 is connected to the sixth film 216 on the opposite side to the seventh film 217 in the thickness direction DT, and is connected to the first lower electrode 31 and the second lower electrode 32 in the thickness direction DT via the second film 212, the third film 213, and the fourth film 214. The sixth film 216 is connected to the seventh film 217 on the opposite side to the first upper electrode 41 and the second upper electrode 42 in the thickness direction DT. The seventh film 217 is connected to the first upper electrode 41 and the second upper electrode 42 in the thickness direction DT. The second film 212, the third film 213, the fourth film 214, and the fifth film 215 are oxide films. The sixth film 216 is a nitride film. The seventh film 217 is an oxide film. The seventh film 217 corresponds to the first layer. The sixth film 216 corresponds to the second layer. The second film 212, the third film 213, the fourth film 214, and the fifth film 215 correspond to the third layer.

[0123] Here, the dielectric constant of the nitride film is higher than that of the oxide film. As a result, the nitride film weakens the electric field compared to the oxide film. Therefore, for example, as shown in FIG. 15 to FIG. 19, even if a foreign object 99 enters the fourth film 214, the electric field from the foreign object 99 is weakened by the sixth film 216. Therefore, at this time, the electric field strength of the seventh film 217 formed on the sixth film 216 becomes small. Therefore, the electric field strength of the first upper electrode 41 formed on the seventh film 217 becomes small. Therefore, the electric field strength between the first upper electrode 41 and the first lower electrode 31 becomes relatively small. Note that FIG. 15 to FIG. 19 are diagrams showing the electric field distribution when a voltage of 2250V is applied between the first lower electrode 31 and the first upper electrode 41. In FIG. 15, the size of the foreign object 99 is 0.01 μm. Furthermore, in FIG. 16, the size of the foreign object 99 is 0.02 μm. In Fig. 17, the size of the foreign matter 99 is set to 0.05 µm. In Fig. 18, the size of the foreign matter 99 is set to 0.1 µm. In Fig. 19, the size of the foreign matter 99 is set to 0.5 µm.

[0124] In addition, this makes it easy to ensure the withstand voltage of the signal transmission device 5 even if the upper first distance Lu1 is smaller than the lower first distance Lb1. Furthermore, even if the upper second distance Lu2 is smaller than the lower second distance Lb2, it makes it easy to ensure the withstand voltage of the signal transmission device 5. Therefore, the upper first distance Lu1 and the upper second distance Lu2 can be made relatively small. Therefore, the thickness between the electrodes can be made small. Thus, the withstand voltage of the signal transmission device 5 is ensured while suppressing an increase in the thickness between the electrodes. Note that the upper first distance Lu1 is the distance from the surface of the sixth film 216 on the first upper electrode 41 side in the thickness direction DT to the first upper electrode 41. The lower first distance Lb1 is the distance from the surface of the sixth film 216 on the first lower electrode 31 side in the thickness direction DT to the first lower electrode 31. The upper side second distance Lu2 is the distance from the surface of the sixth film 216 on the second upper electrode 42 side to the second upper electrode 42 in the thickness direction DT. The lower side second distance Lb2 is the distance from the surface of the sixth film 216 on the second lower electrode 32 side to the second lower electrode 32 in the thickness direction DT. The upper side first distance Lu1 and the upper side second distance Lu2 correspond to the distance from the surface of the second layer on the second electrode side to the second electrode in the thickness direction DT. The lower side first distance Lb1 and the lower side second distance Lb2 correspond to the distance from the surface of the second layer on the first electrode side to the first electrode in the thickness direction DT.

[0125] Second embodiment In the second embodiment, as shown in Fig. 20, the form of the first insulating film 21 is different from that in the first embodiment. Other than this, the second embodiment is similar to the first embodiment.

[0126] Specifically, the first film 211, the second film 212, the third film 213, the fourth film 214, and the fifth film 215 are formed of silicon dioxide or the like as in the first embodiment, and are therefore oxide films. The sixth film 216 is formed of silicon dioxide or the like instead of being a nitride film, and is therefore an oxide film. The seventh film 217 is formed of silicon nitride or the like instead of being an oxide film, and is therefore a nitride film.

[0127] The signal transmission device 5 of the second embodiment is configured as described above. The second embodiment also provides the same effects as the first embodiment.

[0128] Third embodiment 21, the third embodiment differs from the first embodiment in the form of the first insulating film 21. Other than this, the third embodiment is similar to the first embodiment.

[0129] Specifically, the fifth film 215 is not an oxide film, but is made of silicon nitride or the like, and is made of a nitride film. Also, the sixth film 216 is not a nitride film, but is made of silicon dioxide or the like, and is made of an oxide film. Furthermore, the seventh film 217 is made of silicon dioxide or the like, as in the first embodiment, and is made of an oxide film. Note that, although the second film 212, the third film 213, and the fourth film 214 are made of oxide films here, they may be made of silicon nitride or the like, and be made of nitride films.

[0130] The signal transmission device 5 of the third embodiment is configured as described above. The third embodiment also provides the same effects as the first embodiment.

[0131] (Fourth embodiment) 22, the fourth embodiment differs from the first embodiment in the form of the seventh film 217. Other than this, the fourth embodiment is similar to the first embodiment.

[0132] Specifically, the seventh film 217 is not an oxide film, but is made of an electrically insulating resin or the like, thereby being a resin film.

[0133] The signal transmission device 5 of the fourth embodiment is configured as described above. The fourth embodiment also provides the same effects as the first embodiment.

[0134] Fifth embodiment In the first embodiment, the signal transmission device 5 includes a first lower electrode 31, a first upper electrode 41, a first outgoing wiring 61, a second lower electrode 32, a second upper electrode 42 and a second outgoing wiring 62, and includes two capacitors.

[0135] In contrast, in the fifth embodiment, as shown in FIG. 23, the signal transmission device 5 does not include the second lower electrode 32, the second upper electrode 42, and the second lead wiring 62. Therefore, the signal transmission device 5 includes one capacitor. Also, for this reason, the size of the shield part 50 is adjusted. The rest is the same as in the first embodiment. The fifth embodiment also provides the same effects as the first embodiment.

[0136] (Other embodiments) The present disclosure is not limited to the above-described embodiments, and appropriate modifications can be made to the above-described embodiments. Furthermore, in each of the above-described embodiments, it goes without saying that the elements constituting the embodiments are not necessarily essential, except in cases where they are particularly clearly stated as essential or where they are clearly considered essential in principle.

[0137] In each of the above embodiments, the first lower electrode 31, the first upper electrode 41, the second lower electrode 32, and the second upper electrode 42 are formed in an elliptical shape in a cross section cut in a direction perpendicular to the thickness direction DT. In contrast, the first lower electrode 31, the first upper electrode 41, the second lower electrode 32, and the second upper electrode 42 are not limited to being formed in an elliptical shape in a cross section cut in a direction perpendicular to the thickness direction DT. The first lower electrode 31, the first upper electrode 41, the second lower electrode 32, and the second upper electrode 42 may be formed in a polygonal shape having pentagons or more, a star shape, a circle shape, an ellipse shape, or the like in a cross section cut in a direction perpendicular to the thickness direction DT.

[0138] In each of the above embodiments, the first slit 417 and the second slit 427 are formed in an elliptical shape in a cross section cut in a direction perpendicular to the thickness direction DT. In contrast, the first slit 417 and the second slit 427 are not limited to being formed in an elliptical shape in a cross section cut in a direction perpendicular to the thickness direction DT. The first slit 417 and the second slit 427 may be formed in a polygonal shape, a star shape, a circular shape, an elliptical shape, or the like in a cross section cut in a direction perpendicular to the thickness direction DT.

[0139] In each of the above embodiments, the number of capacitors is 1 or 2. However, the number of capacitors is not limited to 1 or 2, and may be 3 or more.

[0140] In each of the above embodiments, the dielectric strength voltage of the third insulating film 23 is lower than the dielectric strength voltage of the second insulating film 22, but this is not limited to the above, and the dielectric strength voltage of the third insulating film 23 may be equal to or higher than the dielectric strength voltage of the second insulating film 22.

[0141] The above embodiments may be combined as appropriate.

[0142] (In view of the present disclosure) [Point 1] A signal transmission device, comprising: A semiconductor substrate (7); an insulating film (21) having electrical insulation properties and formed on the semiconductor substrate; a first electrode (31, 32) covered with the insulating film; a second electrode (41, 42) formed on the insulating film, facing the first electrode in a thickness direction (DT) of the semiconductor substrate, and to which a voltage higher than that applied to the first electrode is applied; Equipped with the first electrode has a first end (315, 325) located at an outer edge of a surface facing the second electrode in the thickness direction, the second electrode has a second end (415, 425) located outside the second electrode in a direction perpendicular to the thickness direction and in contact with the insulating film; the first end is located on the inner side of the second electrode relative to the second end in a direction perpendicular to the thickness direction, The signal transmission device, wherein the distance (Lub1, Lub2) from the first end to the second end in a direction perpendicular to the thickness direction is 10 μm or more. [Point 2] A signal transmission device, comprising: A semiconductor substrate (7); an insulating film (21) having electrical insulation properties and formed on the semiconductor substrate; a first electrode (31, 32) covered with the insulating film; a second electrode (41, 42) formed on the insulating film, facing the first electrode in a thickness direction (DT) of the semiconductor substrate, and to which a voltage higher than that applied to the first electrode is applied; Equipped with the first electrode has an electrode end (315, 325) located at an outer edge of a surface facing the second electrode in the thickness direction, The second electrode is A slit (417, 427) penetrating the second electrode in the thickness direction; a slit end (419, 429) which is an outer edge of a surface of the second electrode that faces the outside of the second electrode in a direction perpendicular to the thickness direction and is in contact with the insulating film; having A signal transmission device, wherein the slit end is located outside the first electrode relative to the electrode end in a direction perpendicular to the thickness direction. [Point 3] A signal transmission device according to Aspect 2, wherein a distance (Lsb1, Lsb2) from the slit end to the electrode end in a direction perpendicular to the thickness direction is 1.0 μm or more. [Point 4] The signal transmission device according to any one of Aspects 1 to 3, wherein a distance (Lud1, Lud2) from the first electrode to the second electrode in the thickness direction is 5.0 μm or more and 8.0 μm or less. [Point 5] The first electrode has a first curved portion (311, 312, 321, 322) formed to be curved convexly in a direction perpendicular to the thickness direction, 5. The signal transmission device according to any one of Aspects 1 to 4, wherein the second electrode has a second curved portion (411, 412, 421, 422) formed to be curved convexly in a direction perpendicular to the thickness direction. [Point 6] The first electrode is formed in an elliptical shape, and therefore the first curved portion is formed in an arc shape, the first electrode has a first straight portion (313, 323) connected to the first curved portion and extending in one direction perpendicular to the thickness direction, the radius (Rb1, Rb2, Rb3, Rb4) of the first curved portion is 20 μm or more and half or less of the length (Wb1, Wb2) of the first straight portion in a direction perpendicular to the thickness direction and the direction in which the first straight portion extends, The second electrode is formed in an elliptical shape, so that the second curved portion has an arc shape. the second electrode has a second straight portion (413, 424) connected to the second curved portion and extending in the one direction, A signal transmission device as described in point 5, wherein the radius (Ru1, Ru2, Ru3, Ru4) of the second curved portions is 20 μm or more and less than half the length (Wu1, Wu2) of the second straight portions in a direction perpendicular to the thickness direction and the direction in which the second straight portions extend. [Point 7] The insulating film is a first layer (217) connected to the second electrode in the thickness direction; a second layer (216) connected in the thickness direction to the side of the first layer opposite to the second electrode; a third layer (212, 213, 214, 215) connected to the second layer on the opposite side to the first layer in the thickness direction and connected to the first electrode in the thickness direction; having The first layer is an oxide film, The second layer is a nitride film, 7. The signal transmission device according to any one of Aspects 1 to 6, wherein the third layer is an oxide film. [Point 8] The insulating film is a first layer (217) connected to the second electrode in the thickness direction; a second layer (216) connected in the thickness direction to the side of the first layer opposite to the second electrode; a third layer (212, 213, 214, 215) connected to the second layer on the opposite side to the first layer in the thickness direction and connected to the first electrode in the thickness direction; having The first layer is a nitride film, The second layer is an oxide film, 7. The signal transmission device according to any one of Aspects 1 to 6, wherein the third layer is an oxide film. [Point 9] The insulating film is a first layer (217) connected to the second electrode in the thickness direction; a second layer (216) connected in the thickness direction to the side of the first layer opposite to the second electrode; a third layer (215) connected to the second layer on the opposite side to the first layer in the thickness direction and connected to the first electrode in the thickness direction; having The first layer is an oxide film, The second layer is an oxide film, 7. The signal transmission device according to any one of Aspects 1 to 6, wherein the third layer is a nitride film. [Point 10] The insulating film is a first layer (217) connected to the second electrode in the thickness direction; a second layer (216) connected in the thickness direction to the side of the first layer opposite to the second electrode; a third layer (212, 213, 214, 215) connected to the second layer on the opposite side to the first layer in the thickness direction and connected to the first electrode in the thickness direction; having The first layer is a resin film, The second layer is a nitride film, 7. The signal transmission device according to any one of Aspects 1 to 6, wherein the third layer is an oxide film. [Point 11] A signal transmission device as described in viewpoint 7 or 10, wherein a distance (Lu1, Lu2) from a surface of the second layer on the second electrode side in the thickness direction to the second electrode is smaller than a distance (Lb1, Lb2) from a surface of the second layer on the first electrode side in the thickness direction to the first electrode. [Explanation of symbols]

[0143] 7. Semiconductor Substrates 21 First insulating film 31 1st lower electrode 41 1st upper electrode 315 Lower side first electrode end 415 Upper first electrode end 417 First Slit 419 First slit end

Claims

1. A signal transmission device, comprising: A semiconductor substrate (7); An insulating film (21) having electrical insulation properties and formed on the semiconductor substrate; a first electrode (31, 32) covered with the insulating film; a second electrode (41, 42) formed on the insulating film, facing the first electrode in a thickness direction (DT) of the semiconductor substrate, and to which a voltage higher than a voltage applied to the first electrode is applied; Equipped with The first electrode has a first end (315, 325) located at an outer edge of a surface facing the second electrode in the thickness direction, the second electrode has a second end (415, 425) located outside the second electrode in a direction perpendicular to the thickness direction and in contact with the insulating film; the first end is located on the inner side of the second electrode relative to the second end in a direction perpendicular to the thickness direction, A signal transmission device, wherein a distance (Lub1, Lub2) from the first end to the second end in a direction perpendicular to the thickness direction is 10 μm or more.

2. A signal transmission device, comprising: A semiconductor substrate (7); An insulating film (21) having electrical insulation properties and formed on the semiconductor substrate; a first electrode (31, 32) covered with the insulating film; a second electrode (41, 42) formed on the insulating film, facing the first electrode in a thickness direction (DT) of the semiconductor substrate, and to which a voltage higher than a voltage applied to the first electrode is applied; Equipped with The first electrode has an electrode end (315, 325) located at an outer edge of a surface facing the second electrode in the thickness direction, The second electrode is A slit (417, 427) penetrating the second electrode in the thickness direction; a slit end (419, 429) which is an outer edge of a surface of the second electrode that faces the outside of the second electrode in a direction perpendicular to the thickness direction and is in contact with the insulating film; having A signal transmission device, wherein the slit end is located outside the first electrode relative to the electrode end in a direction perpendicular to the thickness direction.

3. 3. The signal transmission device according to claim 2, wherein a distance (Lsb1, Lsb2) from the slit end to the electrode end in a direction perpendicular to the thickness direction is 1.0 μm or more.

4. 4. The signal transmission device according to claim 1, wherein a distance (Lud1, Lud2) from the first electrode to the second electrode in the thickness direction is 5.0 μm or more and 8.0 μm or less.

5. The first electrode has a first curved portion (311, 312, 321, 322) formed to be curved convexly in a direction perpendicular to the thickness direction, 4. The signal transmission device according to claim 1, wherein the second electrode has a second curved portion (411, 412, 421, 422) formed to be curved convexly in a direction perpendicular to the thickness direction.

6. The first electrode is formed in an elliptical shape, and therefore the first curved portion is formed in an arc shape, The first electrode has a first straight portion (313, 323) connected to the first curved portion and extending in one direction perpendicular to the thickness direction, The radius (Rb1, Rb2, Rb3, Rb4) of the first curved portion is 20 μm or more and half or less of the length (Wb1, Wb2) of the first straight portion in a direction perpendicular to the thickness direction and the direction in which the first straight portion extends, The second electrode is formed in an elliptical shape, so that the second curved portion has an arc shape, The second electrode has a second linear portion (413, 424) connected to the second curved portion and extending in the one direction, 6. The signal transmission device according to claim 5, wherein the radius (Ru1, Ru2, Ru3, Ru4) of the second curved portion is 20 μm or more and is less than half the length (Wu1, Wu2) of the second straight portion in a direction perpendicular to the thickness direction and the direction in which the second straight portion extends.

7. The insulating film is A first layer (217) connected to the second electrode in the thickness direction; a second layer (216) connected to the first layer on the opposite side to the second electrode in the thickness direction; a third layer (212, 213, 214, 215) connected to the second layer on the opposite side to the first layer in the thickness direction and connected to the first electrode in the thickness direction; having The first layer is an oxide film, The second layer is a nitride film, 3. The signal transmission device according to claim 1, wherein the third layer is an oxide film.

8. The insulating film is A first layer (217) connected to the second electrode in the thickness direction; a second layer (216) connected to the first layer on the opposite side to the second electrode in the thickness direction; a third layer (212, 213, 214, 215) connected to the second layer on the opposite side to the first layer in the thickness direction and connected to the first electrode in the thickness direction; having The first layer is a nitride film, The second layer is an oxide film, 3. The signal transmission device according to claim 1, wherein the third layer is an oxide film.

9. The insulating film is A first layer (217) connected to the second electrode in the thickness direction; a second layer (216) connected to the first layer on the opposite side to the second electrode in the thickness direction; a third layer (215) connected to the second layer on the opposite side to the first layer in the thickness direction and connected to the first electrode in the thickness direction; having The first layer is an oxide film, The second layer is an oxide film, 3. The signal transmission device according to claim 1, wherein the third layer is a nitride film.

10. The insulating film is A first layer (217) connected to the second electrode in the thickness direction; a second layer (216) connected to the first layer on the opposite side to the second electrode in the thickness direction; a third layer (212, 213, 214, 215) connected to the second layer on the opposite side to the first layer in the thickness direction and connected to the first electrode in the thickness direction; having The first layer is a resin film, The second layer is a nitride film, 3. The signal transmission device according to claim 1, wherein the third layer is an oxide film.

11. 8. The signal transmission device according to claim 7, wherein a distance (Lu1, Lu2) from a surface of the second layer on the second electrode side in the thickness direction to the second electrode is smaller than a distance (Lb1, Lb2) from a surface of the second layer on the first electrode side in the thickness direction to the first electrode.

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