Signal transmission device

Abstract

This provides a signal transmission element that eliminates the need for a process of drawing the lower layer coil to the element surface. [Solution] The semiconductor substrate comprises a first insulating layer, first and second coils on the same, a second insulating layer covering the first and second coils, third and fourth coils on the same, and a protective film covering the third and fourth coils. The first and third coils are magnetically coupled, the second and fourth coils are magnetically coupled, and the first and second coils are connected to each other such that the current generated by mutual induction between the first and third coils flows into the second coil. The protective film has multiple openings that reach the two ends of the third coil and the two ends of the fourth coil.

Description

Technical Field

[0001] The present disclosure relates to a signal transmission element, and particularly to an insulated signal transmission element.

Background Art

[0002] An insulated signal transmission element (transformer element) is an element that transmits a signal while being electrically and physically insulated between an input and an output. For example, in a gate driver of a power chip, a control microcomputer is connected to the input side, and a gate of the power chip is connected to the output side, and the signal of the microcomputer is transmitted to the power chip. When the power chip to which a high voltage is applied breaks down, the input side and the output side are electrically and physically insulated for the safety of the system such as protection of the microcomputer and prevention of electric shock.

[0003] In an insulated signal transmission element that forms a magnetic coupling in a direction perpendicular to a semiconductor substrate, in order to draw out an electrode of a lower layer coil close to the semiconductor substrate to the element surface, for example, as shown in FIG. 21 of Patent Document 1, it was necessary to etch a thick insulating layer between the upper layer coil and the lower layer coil.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In Patent Document 1, in order to draw out the lower layer coil to the element surface, it is necessary to etch a thick insulating layer between the upper layer coil and the lower layer coil, and there is a problem that the processing load of the wafer process becomes high.

[0006] The present disclosure has been made to solve the above problems, and an object thereof is to provide a signal transmission element that does not require a step of drawing out a lower layer coil to the element surface. [Means for solving the problem]

[0007] The signal transmission element according to this disclosure comprises a first insulating layer provided on a semiconductor substrate, a first coil and a second coil provided adjacent to each other on the first insulating layer, a second insulating layer provided on the first insulating layer and covering the first and second coils, a third coil and a fourth coil provided adjacent to each other on the second insulating layer, and an insulating protective film provided on the second insulating layer and covering the third and fourth coils, wherein the first coil and the third coil are magnetically coupled, the second coil and the fourth coil are magnetically coupled, the first and second coils are connected to each other such that a current generated by mutual induction between the first coil and the third coil flows to the second coil, and the protective film has a plurality of openings reaching two ends of the third coil and two ends of the fourth coil. [Effects of the Invention]

[0008] According to the signal transmission element of this disclosure, since both the third coil on the input side and the fourth coil on the output side are provided on the second insulating layer, even if the thickness of the second insulating layer increases, the input and output electrodes can be obtained by simply removing the protective film without removing the second insulating layer, and a signal transmission element can be obtained that does not require the process of bringing the lower layer coil to the element surface. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a cross-sectional view showing the configuration of the signal transmission element in Embodiment 1. [Figure 2] Figure 2 is a schematic plan view showing the planar configuration of the lower metal wiring layer of the signal transmission element in Embodiment 1. [Figure 3] Figure 3 is a schematic plan view showing the planar configuration of the upper metal wiring layer of the signal transmission element in Embodiment 1. [Figure 4]Figure 4 is a schematic plan view showing a modified planar configuration of the lower metal wiring layer of the signal transmission element in Embodiment 1. [Figure 5] Figure 5 is a cross-sectional view showing a modified configuration of the signal transmission element of Embodiment 1. [Figure 6] Figure 6 is a cross-sectional view showing the configuration of the signal transmission element in Embodiment 2. [Figure 7] Figure 7 is a schematic plan view showing the planar configuration of the lower metal wiring layer of the signal transmission element in Embodiment 2. [Figure 8] Figure 8 is a schematic plan view showing the planar configuration of the upper metal wiring layer of the signal transmission element in Embodiment 2. [Figure 9] Figure 9 is a schematic plan view showing the planar configuration of the uppermost metal wiring layer of the signal transmission element in Embodiment 2. [Figure 10] Figure 10 is a cross-sectional view showing a modified configuration of the signal transmission element according to Embodiment 2. [Figure 11] Figure 11 is a schematic plan view showing a modified planar configuration of the upper metal wiring layer of the signal transmission element in Embodiment 2. [Modes for carrying out the invention]

[0010] <Embodiment 1> <Device configuration> Figure 1 is a cross-sectional view showing the configuration of a signal transmission element 1 according to Embodiment 1 of the present disclosure. As shown in Figure 1, the signal transmission element 1 has an insulating layer 200 (first insulating layer) provided on the surface of a semiconductor substrate 100, and metal wiring layers 311 and 321 are provided inside the insulating layer 200. The semiconductor substrate 100 can be a silicon substrate or a silicon carbide substrate, and the impurities can be N-type or P-type. In addition, a conductor or an insulator can be used as the substrate. Furthermore, the metal wiring layers described below can all be formed from metals such as copper or aluminum.

[0011] On top of the insulating layer 200, a metal wiring layer 411 (first coil) and a metal wiring layer 421 (second coil) are provided, and the metal wiring layers 411 and 421 are covered with an insulating layer 500 (second insulating layer). The metal wiring layer 311 and the central end portion 411a of the metal wiring layer 411 are electrically connected via a contact hole CH1, and the metal wiring layer 311 and the outer peripheral end portion 421b of the metal wiring layer 421 are electrically connected via a contact hole CH2. The metal wiring layer 321 and the central end portion 421a of the metal wiring layer 421 are electrically connected via a contact hole CH3.

[0012] On top of the insulating layer 500, a metal wiring layer 611 (third coil) and a metal wiring layer 621 (fourth coil) are provided, and the metal wiring layers 611 and 621 are covered with an insulating protective film 700 such as silicon nitride or silicon oxide. Also, the insulating layers 200 and 500 can be formed of, for example, silicon oxide.

[0013] The metal wiring layer 611 has end portions 611a and 611b, the metal wiring layer 621 has end portions 621a and 621b, and the protective film 700 is provided with a plurality of openings OP reaching the respective end portions.

[0014] FIG. 2 is a plan view schematically showing the planar configuration of the lower metal wiring layers 311, 321, 411, and 421. The lower metal wiring layers 311 and 321 are described by being superimposed on the metal wiring layers 411 and 421 for convenience. Note that the cross-sectional view in the direction of the arrow along line A-A in FIG. 2 is included in the cross-sectional view of FIG. 1.

[0015] The metal wiring layer 411 has a spiral shape in plan view, and in FIG. 2, it has a left-handed spiral shape from the central end portion 411a toward the outer peripheral end portion 411b. The metal wiring layer 421 is arranged at a position separated from the metal wiring layer 411 by a certain distance in plan view, has a reverse spiral shape to the metal wiring layer 411, and in FIG. 2, has a right-handed spiral shape from the central end portion 421a toward the outer peripheral end portion 421b.

[0016] FIG. 3 is a plan view schematically showing a planar configuration of the metal wiring layers 611 and 621, and a cross-sectional view taken along the line A-A in FIG. 3 is included in the cross-sectional view of FIG. 1.

[0017] The metal wiring layer 611 is provided above the metal wiring layer 411 via the insulating layer 500, has a spiral shape in a plan view, and is magnetically coupled with the metal wiring layer 411. The metal wiring layer 621 is provided above the metal wiring layer 421 via the insulating layer 500, has a spiral shape in a plan view, and is magnetically coupled with the metal wiring layer 421.

[0018] In FIG. 3, the spiral of the metal wiring layer 611 is in a left-handed direction from the central end portion 611a to the outer peripheral end portion 611b, and the spiral of the metal wiring layer 621 is in a right-handed direction from the central end portion 621a to the outer peripheral end portion 621b. However, the winding directions of the metal wiring layers 611 and 621 can also be the same direction. Also, the winding directions with respect to the lower metal wiring layers 411 and 421 can be the same direction or the opposite direction, respectively.

[0019] <Operation and Effect> In the signal transmission element 1 of the first embodiment, the current signal input between the central end portion 611a and the outer peripheral end portion 611b of the metal wiring layer 611 is output as a current signal between the central end portion 621a and the outer peripheral end portion 621b of the metal wiring layer 621. When a current is input from the central end portion 611a to the outer peripheral end portion 611b in FIG. 3, a magnetic field is generated in the region of the metal wiring layer 611 from the back surface of the paper toward the front surface of the paper. An induced electromotive force is generated in the metal wiring layer 411 due to the mutual induction by this magnetic field, and a current flows from the central end portion 411a to the outer peripheral end portion 411b in FIG. 2. This current flows from the central end portion 421a to the outer peripheral end portion 421b of the metal wiring layer 421 via the metal wiring layers 321 and 311. When a current flows from the central end portion 421a to the outer peripheral end portion 421b, a magnetic field is generated in the region of the metal wiring layer 421 from the front surface of the paper toward the back surface of the paper. An induced electromotive force is generated in the metal wiring layer 621 due to the mutual induction by this magnetic field, and a current signal is output from the central end portion 621a to the outer peripheral end portion 621b in FIG. 3.

[0020] As a result of the above operation, the current signal input between the central end 611a and the outer end 611b of the metal wiring layer 611 is output as a current signal between the central end 621a and the outer end 621b of the metal wiring layer 621.

[0021] In Figure 2, the magnetic field generated by the input current is directed from the back of the paper to the front of the paper within the region of the metal wiring layer 411, and from the front of the paper to the back of the paper outside the region of the metal wiring layer 411, i.e., in the region where the metal wiring layer 411 is not provided.

[0022] Furthermore, in Figure 2, the magnetic field generated by the input current is directed from the front to the back of the paper within the region of the metal wiring layer 421, and from the back to the front of the paper outside the region of the metal wiring layer 421, i.e., in the region where the metal wiring layer 421 is not provided. Therefore, the magnetic field within the region of the metal wiring layer 421, which is the transmitted signal, is not canceled out by the magnetic field from the metal wiring layer 411, but is strengthened, allowing for more efficient signal transmission.

[0023] Furthermore, as shown in Figure 1, an insulating layer 500 is interposed between metal wiring layer 411 and metal wiring layer 611, and between metal wiring layer 421 and metal wiring layer 621. Therefore, while signal transmission occurs between metal wiring layer 611 and metal wiring layer 621 through mutual induction by a magnetic field, they are electrically insulated.

[0024] In order to increase the dielectric strength, the thickness of the insulating layer 500 needs to be increased. However, in the signal transmission element 1 of Embodiment 1, since both the input-side metal wiring layer 611 and the output-side metal wiring layer 621 are provided on top of the insulating layer 500, even if the thickness of the insulating layer 500 is increased, the input-side and output-side electrodes can be obtained by etching the protective film 700 without etching the insulating layer 500.

[0025] <Example 1> Figure 4 is a plan view showing a modified combination of spiral winding directions for the metal wiring layers 411 and 421 shown in Figure 2, and is different from the combination of spiral winding directions for the metal wiring layers 411 and 421 shown in Figure 2.

[0026] In other words, the spiral of the metal wiring layer 412 in Figure 4 is counterclockwise, from the central end 412a to the outer end 412b, and the spiral of the metal wiring layer 422 is counterclockwise, from the central end 422a to the outer end 422b, and they have the same winding direction.

[0027] The central end portion 412a of the metal wiring layer 412 and the central end portion 422a of the metal wiring layer 422 are electrically connected by the metal wiring layer 312 via a contact hole (not shown) formed in the insulating layer 200 (Figure 1).

[0028] The outer peripheral end 412b of metal wiring layer 412 and the outer peripheral end 422b of metal wiring layer 422 are connected by metal wiring layer 432, which is the same layer, above the insulating layer 200. For this reason, the boundary between the outer peripheral end 412b, metal wiring layer 432, and outer peripheral end 422b is not shown in Figure 4.

[0029] Similar to the metal wiring layers 411 and 421 shown in Figure 2, when current is input from the central end 611a to the outer end 611b in Figure 3, a magnetic field is generated within the region of metal wiring layer 611, extending from the back of the paper to the front of the paper. Mutual induction due to this magnetic field generates an induced electromotive force in metal wiring layer 412, causing current to flow from the central end 412a to the outer end 412b in Figure 4. This current flows from the outer end 422b to the central end 422a of metal wiring layer 422 via metal wiring layers 432 and 312. When current flows from the outer end 421b to the central end 422a, a magnetic field is generated within the region of metal wiring layer 422, extending from the front of the paper to the back of the paper. Mutual induction due to this magnetic field generates an induced electromotive force in metal wiring layer 621, outputting a current signal from the central end 621a to the outer end 621b in Figure 3.

[0030] By the above operation, the current signal input between the central end portion 611a and the outer peripheral end portion 611b of the metal wiring layer 611 is output as a current signal between the central end portion 621a and the outer peripheral end portion 621b of the metal wiring layer 621.

[0031] In addition, the magnetic field in the region of the metal wiring layer 422 that becomes the transmission signal is not canceled by the magnetic field from the metal wiring layer 412, but is strengthened, and the signal can be transmitted more efficiently.

[0032] <Modified Example 2> FIG. 5 is a cross-sectional view showing the configuration of the signal transmission element 1A when the insulating layer 500 is thinned to form the insulating layer 510. In FIG. 5, the same components as those of the signal transmission element 1 described using FIG. 1 are denoted by the same reference numerals, and redundant explanations are omitted.

[0033] In the signal transmission element 1 of Embodiment 1, the input current signal is transmitted through the insulating layer 500 between the metal wiring layer 611 and the metal wiring layer 411, and is transmitted through the insulating layer 500 between the metal wiring layer 421 and the metal wiring layer 621. Therefore, it is transmitted through the insulating layer 500 twice. For this reason, the insulating layer 500 can be thinned.

[0034] That is, when the thickness of the insulating layer 500 that satisfies the required insulation breakdown voltage between the metal wiring layers 411 and 421 and the metal wiring layers 611 and 621 is, for example, L, the input current signal is transmitted through the insulating layer 500 twice. Therefore, the thickness L1 of the insulating layer 510 can be set to L / 2 ≦ L1 < L, that is, half of the thickness of the insulating layer 500. For this reason, the processing load of the insulating layer 510 can be reduced.

[0035] <Embodiment 2> In Embodiment 1 described using FIGS. 1 to 4, there are two adjacent spiral metal wiring layers in the same layer, that is, the metal wiring layers 411 and 421 in FIG. 2. However, a configuration in which a plurality of blocks of this combination are connected can also be adopted.

[0036] Hereinafter, an embodiment 2 of the present disclosure, in which two blocks of the configuration of embodiment 1 are connected, will be described with reference to Figures 6 to 8.

[0037] Figure 6 is a cross-sectional view showing the configuration of the signal transmission element 2 in Embodiment 2 of the present disclosure. As shown in Figure 6, the signal transmission element 2 has an insulating layer 200 provided on the surface of a semiconductor substrate 100, and metal wiring layers 313, 323, 333, and 343 are provided inside the insulating layer 200.

[0038] Metal wiring layers 413, 423, 433, and 443 are provided on top of the insulating layer 200, and these metal wiring layers 413, 423, 433, and 443 are covered with the insulating layer 500. Metal wiring layer 313 and the central end portion 413a of metal wiring layer 413 are electrically connected via a contact hole CH4, and metal wiring layer 313 and the outer peripheral end portion 423b of metal wiring layer 423 are electrically connected via a contact hole CH5. Metal wiring layer 323 and the central end portion 423a of metal wiring layer 423 are electrically connected via a contact hole CH6.

[0039] The metal wiring layer 333 and the central end portion 433a of the metal wiring layer 433 are electrically connected via contact hole CH7, and the metal wiring layer 333 and the outer peripheral end portion 443b of the metal wiring layer 443 are electrically connected via contact hole CH8. The metal wiring layer 343 and the central end portion 443a of the metal wiring layer 443 are electrically connected via contact hole CH9.

[0040] Metal wiring layers 613, 623, 633, and 643 are provided on top of the insulating layer 500, and these metal wiring layers 613, 623, 633, and 643 are covered with an insulating layer 800 (a third insulating layer). The insulating layer 800 can be formed from, for example, silicon oxide.

[0041] Metal wiring layers 913b, 913a, 923, 933, 943a, and 943b are provided on top of the insulating layer 800. The metal wiring layers 913b, 913a, 923, 933, 943a, and 943b are covered with an insulating protective film 700. The protective film 700 is provided with a number of openings OP1 that reach each of the metal wiring layers 913b, 913a, 943a, and 943b.

[0042] The outer peripheral end 613b of metal wiring layer 613 and metal wiring layer 913b are electrically connected via contact hole CH10, and the central peripheral end 613a of metal wiring layer 613 and metal wiring layer 913a are electrically connected via contact hole CH11. The central peripheral end 623a of metal wiring layer 623 and metal wiring layer 923 are electrically connected via contact hole CH12, and the outer peripheral end 633b of metal wiring layer 633 and metal wiring layer 923 are electrically connected via contact hole CH13. The central peripheral end 633a of metal wiring layer 633 and metal wiring layer 933 are electrically connected via contact hole CH14. The central peripheral end 643a of metal wiring layer 643 and metal wiring layer 943a are electrically connected via contact hole CH15, and the outer peripheral end 643b of metal wiring layer 643 and metal wiring layer 943b are electrically connected via contact hole CH16.

[0043] In the signal transmission element 2 of the second embodiment, the current signal input between the metal wiring layer 913a and the metal wiring layer 913b is output between the metal wiring layer 943a and the metal wiring layer 943b.

[0044] In the signal transmission element 2 shown in Figure 6, the left portion of the diagram, which has metal wiring layers 313 and 323 and metal wiring layers 613 and 623, is referred to as the first block, and the right portion of the diagram, which has metal wiring layers 333 and 343 and metal wiring layers 633 and 643, is referred to as the second block.

[0045] Figure 7 is a schematic plan view showing the planar configuration of metal wiring layers 413, 423, 433, and 443. For convenience, the lower metal wiring layers 313 and 323 are shown superimposed on 413 and 423, and the lower metal wiring layers 333 and 343 are shown superimposed on 433 and 443. Note that the cross-section indicated by the arrow along line BB in Figure 7 is included in the cross-sectional view in Figure 6.

[0046] The plan view shapes of metal wiring layers 413 and 423, and metal wiring layers 433 and 443 are the same as the plan view shapes of metal wiring layers 411 and 421 shown in Figure 2.

[0047] Figure 8 is a schematic plan view showing the planar configuration of metal wiring layers 613, 623, 633, and 643, and also shows the upper metal wiring layers 913b, 913a, 923, 933, 943a, and 943b. The cross-section in the direction indicated by the arrow along line BB in Figure 8 is included in the cross-sectional view in Figure 6.

[0048] The plan view shapes of metal wiring layers 613 and 623, and metal wiring layers 633 and 643 are the same as the plan view shapes of metal wiring layers 611 and 621 shown in Figure 3, but the central end 423a of metal wiring layer 623 and the outer end 633b of metal wiring layer 633 are electrically connected by metal wiring layer 923. Also, the central end 633a of metal wiring layer 633 and the outer end 623b of metal wiring layer 623 are electrically connected by metal wiring layer 933.

[0049] In Figure 8, the metal wiring layers 913b, 913a, 943a, and 943b are formed such that, in a plan view, they are smaller than the metal wiring layers 613b, 613a, 643a, and 643b, and their outlines are positioned inside the outlines of the metal wiring layers 613b, 613a, 643a, and 643b, but are not limited to this configuration.

[0050] For example, as shown in Figure 9, the metal wiring layers 913b and 913a are larger than the metal wiring layers 613b and 613a, and their outlines are formed to extend beyond the outlines of the metal wiring layers 613b and 613a.

[0051] There are no particular restrictions on the relative sizes of metal wiring layers 613b and 913b, or metal wiring layers 613a and 913a. The same applies to metal wiring layers 643b and 943b, and metal wiring layers 643a and 943a.

[0052] <Effects> The signal transmission element 2 of Embodiment 2 described above, like the signal transmission element 1 of Embodiment 1, has the effect of being able to obtain input and output electrodes simply by etching the protective film 700, without etching the insulating layer 500, even if the thickness of the insulating layer 500 is increased.

[0053] In addition, by connecting multiple blocks of the configuration of Embodiment 1, the signal is transmitted between blocks through the insulating layer 500 two or more times, and the dielectric strength between the input and output can be increased without increasing the thickness of the insulating layer 500.

[0054] In other words, in the signal transmission element 1 of Embodiment 1, the current signal input to the outer peripheral end 611b of the metal wiring layer 611 is transmitted through the insulating layer 500 between the metal wiring layer 611 and the metal wiring layer 411, and then through the insulating layer 500 between the metal wiring layer 421 and the metal wiring layer 621, so the signal is transmitted through the insulating layer 500 twice.

[0055] On the other hand, in the signal transmission element 2 of the second embodiment, the current signal input to the metal wiring layer 613b is transmitted through the insulating layer 500 between the metal wiring layer 613 and the metal wiring layer 413, through the insulating layer 500 between the metal wiring layer 423 and the metal wiring layer 623, through the insulating layer 500 between the metal wiring layer 633 and the metal wiring layer 433, and through the insulating layer 500 between the metal wiring layer 443 and the metal wiring layer 643. As a result, the signal is transmitted through the insulating layer 500 four times, which allows for a higher dielectric strength.

[0056] <Example 1> In the second embodiment shown in Figure 6, the signal transmission element 2 was formed using a semiconductor substrate 100 as the substrate, but an SOI (Silicon On Insulator) substrate can also be used.

[0057] Figure 10 is a cross-sectional view showing the configuration of the signal transmission element 2A using the SOI substrate 100A. In Figure 10, components identical to those of the signal transmission element 2 described using Figure 6 are denoted by the same reference numerals, and redundant explanations are omitted.

[0058] As shown in Figure 10, the signal transmission element 2A has the layers from the insulating layer 200 upwards provided on the SOI substrate 100A. The SOI substrate 100A has a semiconductor substrate 110 on which an embedded insulating layer 120 made of silicon oxide is provided, and a semiconductor layer 130 made of single crystal silicon is provided on the embedded insulating layer 120, with the insulating layer 200 provided on the semiconductor layer 130. Note that the semiconductor substrate 110 can be a silicon substrate, and the impurities can be either N-type or P-type.

[0059] The embedded insulating layer 120 is, for example, a thermal oxide film. The conductivity types of the semiconductor substrate 110 and the semiconductor layer 130 can be either N-type or P-type.

[0060] In the semiconductor layer 130, an isolation insulating layer 140 is formed between the metal wiring layer 423 and the metal wiring layer 433 when viewed from above, thereby electrically separating them.

[0061] The upper end of the isolation insulating layer 140 is in contact with the insulating layer 200, and the lower end of the isolation insulating layer 140 is in contact with the embedded insulating layer 120. The isolation insulating layer 140 can be formed by thermal oxidation of the semiconductor layer 130, or it can be formed by embedding the insulating layer after etching the semiconductor layer 130.

[0062] By using the SOI substrate 100A and providing a separation insulating layer 140, dielectric breakdown between the metal wiring layers 413 and 423 and the metal wiring layers 433 and 443 via the substrate can be suppressed, and the dielectric breakdown voltage between the input and output can be increased without increasing the thickness of the insulating layer 200.

[0063] <Modification 2> Figure 11 is a plan view showing a modified combination of spiral winding directions for the metal wiring layers 623 and 633 shown in Figure 8, and is different from the combination of spiral winding directions for the metal wiring layers 623 and 633 shown in Figure 8.

[0064] In other words, the spiral of the metal wiring layer 655 in Figure 11 is counter-clockwise, from the central end 655a to the outer end 655b, and the spiral of the metal wiring layer 633 is counter-clockwise, from the central end 633a to the outer end 633b, and they have the same winding direction.

[0065] The central end portion 655a of the metal wiring layer 655 and the central end portion 633a of the metal wiring layer 633 are electrically connected by the metal wiring layer 935 via a contact hole (not shown) formed in the insulating layer 800 (Figure 6).

[0066] The outer peripheral ends 655b of metal wiring layer 655 and 633b of metal wiring layer 633 are connected by metal wiring layer 934, which is the same layer, above the insulating layer 500. For this reason, the boundaries between the outer peripheral ends 655b, metal wiring layer 934, and outer peripheral end 633b are not shown in Figure 11.

[0067] Furthermore, within the scope of this disclosure, it is possible to freely combine each embodiment, or to modify or omit each embodiment as appropriate.

[0068] The above-described disclosure is summarized below as an appendix.

[0069] (Note 1) A first insulating layer provided on a semiconductor substrate, A first coil and a second coil are provided adjacent to each other on the first insulating layer, A second insulating layer provided on the first insulating layer and covering the first and second coils, and a third coil and a fourth coil provided adjacent to each other on the second insulating layer, The device comprises an insulating protective film provided on the second insulating layer and covering the third and fourth coils, The first coil and the third coil are magnetically coupled. The second coil and the fourth coil are magnetically coupled. The first and second coils are connected to each other such that the current generated by mutual induction between the first coil and the third coil flows through the second coil. The protective film is a signal transmission element having a plurality of openings that reach two ends of the third coil and two ends of the fourth coil.

[0070] (Note 2) The first coil and the second coil are wound in opposite directions, and the central end of the first coil and the outer end of the second coil are electrically connected. The signal transmission element described in Appendix 1, wherein the outer peripheral end of the first coil and the central end of the second coil are electrically connected.

[0071] (Note 3) The first coil and the second coil have the same winding direction, and the central end of the first coil and the central end of the second coil are electrically connected. The signal transmission element described in Appendix 1, wherein the outer peripheral end of the first coil and the outer peripheral end of the second coil are connected.

[0072] (Note 4) The thickness of the second insulating layer is A signal transmission element according to any one of the appendices 1 to 3, wherein the thickness is set to half the thickness required for the dielectric strength between the first and second coils and the third and fourth coils.

[0073] (Note 5) A first insulating layer provided on a semiconductor substrate, A first coil and a second coil are provided adjacent to each other on the first insulating layer, A second insulating layer provided on the first insulating layer and covering the first and second coils, and a third coil and a fourth coil provided adjacent to each other on the second insulating layer, A third insulating layer provided on the second insulating layer and covering the third and fourth coils, and a plurality of wiring layers provided on the third insulating layer, The device comprises an insulating protective film provided on the third insulating layer and covering the plurality of wiring layers, wherein the first coil and the third coil are magnetically coupled. The second coil and the fourth coil are magnetically coupled. A first block in which the first and second coils are connected to each other such that the current generated by mutual induction between the first coil and the third coil flows through the second coil, A second block having the same configuration as the first block, The first and second blocks are arranged to be continuous in a plan view. The fourth coil of the first block and the third coil of the second block are connected to each other such that the current flowing through the fourth coil of the first block flows through the third coil of the second block. The protective film has a plurality of openings that reach two ends of the third coil of the first block and two ends of the fourth coil of the second block, and is a signal transmission element.

[0074] (Note 6) The fourth coil of the first block and the third coil of the second block are wound in opposite directions, and the central end of the fourth coil of the first block and the outer peripheral end of the third coil of the second block are electrically connected. The signal transmission element described in Appendix 5, wherein the outer peripheral end of the fourth coil of the first block and the central end of the third coil of the second block are electrically connected.

[0075] (Note 7) The aforementioned semiconductor substrate is A silicon substrate and An embedded insulating layer provided on the silicon substrate, The SOI substrate has a semiconductor layer provided on the aforementioned embedded insulating layer, The aforementioned semiconductor layer is The signal transmission element according to Appendix 5, having a separation insulating layer provided in a portion corresponding to the space between the first block and the second block in a plan view, so as to reach the embedded insulating layer.

[0076] (Note 8) The fourth coil of the first block and the third coil of the second block have the same winding direction, and the central end of the fourth coil of the first block and the central end of the third coil of the second block are connected. The signal transmission element described in Appendix 5, wherein the outer peripheral end of the fourth coil of the first block and the outer peripheral end of the third coil of the second block are connected. [Explanation of Symbols]

[0077] 100 Semiconductor substrate, 100A SOI substrate, 110 Silicon substrate, 120 Embedded insulating layer, 130 Semiconductor layer, 140 Isolation insulating layer, 200, 500, 800 Insulating layer, 700 Protective film, 311, 321, 413, 423, 611, 613, 621, 623 Metal wiring layer, 411a, 421a, 623a, 633a, 655a Central edge, 411b, 421b, 623b, 633b, 633b Outer edge.

Claims

1. A first insulating layer provided on a semiconductor substrate, A first coil and a second coil are provided adjacent to each other on the first insulating layer, A second insulating layer is provided on the first insulating layer and covers the first and second coils, A third coil and a fourth coil are provided adjacent to each other on the second insulating layer, The device comprises an insulating protective film provided on the second insulating layer and covering the third and fourth coils, The first coil and the third coil are magnetically coupled. The second coil and the fourth coil are magnetically coupled. The first and second coils are connected to each other such that the current generated by mutual induction between the first coil and the third coil flows through the second coil. The protective film is a signal transmission element having a plurality of openings that reach two ends of the third coil and two ends of the fourth coil.

2. The first coil and the second coil are wound in opposite directions, and the central end of the first coil and the outer end of the second coil are electrically connected. The signal transmission element according to claim 1, wherein the outer peripheral end of the first coil and the central end of the second coil are electrically connected.

3. The first coil and the second coil have the same winding direction, and the central end of the first coil and the central end of the second coil are electrically connected. The signal transmission element according to claim 1, wherein the outer peripheral end of the first coil and the outer peripheral end of the second coil are connected.

4. The thickness of the second insulating layer is A signal transmission element according to any one of claims 1 to 3, wherein the thickness is set to half the thickness required for the dielectric breakdown voltage between the first and second coils and the third and fourth coils.

5. A first insulating layer provided on a semiconductor substrate, A first coil and a second coil are provided adjacent to each other on the first insulating layer, A second insulating layer is provided on the first insulating layer and covers the first and second coils, A third coil and a fourth coil are provided adjacent to each other on the second insulating layer, A third insulating layer provided on the second insulating layer and covering the third and fourth coils, Multiple wiring layers provided on the third insulating layer, The device comprises an insulating protective film provided on the third insulating layer and covering the plurality of wiring layers, The first coil and the third coil are magnetically coupled. The second coil and the fourth coil are magnetically coupled. A first block in which the first and second coils are connected to each other such that the current generated by mutual induction between the first coil and the third coil flows through the second coil, It comprises a second block having the same configuration as the first block, The first and second blocks are arranged to be continuous in a plan view. The fourth coil of the first block and the third coil of the second block are connected to each other such that the current flowing through the fourth coil of the first block flows through the third coil of the second block. The protective film has a plurality of openings that reach two ends of the third coil of the first block and two ends of the fourth coil of the second block, and is a signal transmission element.

6. The fourth coil of the first block and the third coil of the second block are wound in opposite directions, and the central end of the fourth coil of the first block and the outer peripheral end of the third coil of the second block are electrically connected. The signal transmission element according to claim 5, wherein the outer peripheral end of the fourth coil of the first block and the central end of the third coil of the second block are electrically connected.

7. The aforementioned semiconductor substrate is A silicon substrate and An embedded insulating layer provided on the silicon substrate, The SOI substrate has a semiconductor layer provided on the aforementioned embedded insulating layer, The aforementioned semiconductor layer is The signal transmission element according to claim 5, further comprising a separation insulating layer provided in a portion corresponding to the space between the first block and the second block in a plan view, extending to the embedded insulating layer.

8. The fourth coil of the first block and the third coil of the second block have the same winding direction, and the central end of the fourth coil of the first block and the central end of the third coil of the second block are connected. The signal transmission element according to claim 5, wherein the outer peripheral end of the fourth coil of the first block and the outer peripheral end of the third coil of the second block are connected.

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