Insulation device and manufacturing method of the insulation device
Patent Information
- Application Number
- JP2023148771
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-09-13
- Publication Date
- 2025-03-26
Smart Images
Figure 2025041455000001_ABST
Abstract
Description
[Technical field]
[0001] SUMMARY OF THE DISCLOSURE FIELD OF THE DISCLOSURE Embodiments of the present invention relate to an insulating device and a method for making an insulating device. [Background technology]
[0002] Isolation devices transmit signals by utilizing changes in magnetic or electric fields while blocking current. There is a demand for these isolation devices to simultaneously improve their insulation life and suppress warping. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] JP 2020-152253 A Summary of the Invention [Problem to be solved by the invention]
[0004] The problem to be solved by the present invention is to provide an insulating device and a method for manufacturing an insulating device that can achieve both an improvement in insulation life and suppression of warping. [Means for solving the problem]
[0005] The insulation device according to the embodiment includes an insulation section, a first coil, and a second coil. The first coil is provided inside the insulation section. The second coil is provided inside the insulation section. The second coil faces the first coil in a first direction. The insulation section has a first insulation layer, a second insulation layer, and a third insulation layer. The first coil is provided inside the first insulation layer. The second coil is provided inside the second insulation layer. The third insulation layer is located between the first insulation layer and the second insulation layer in the first direction. The first insulation layer has a first central insulation region and a first outer peripheral insulation region. The first coil is provided inside the first central insulation region. The first outer peripheral insulation region surrounds the first central insulation region along a first surface perpendicular to the first direction. The second insulation layer has a second central insulation region and a second outer peripheral insulation region. The second coil is provided inside the second central insulating region. The second peripheral insulating region surrounds the second central insulating region along the first surface. The third insulating layer has a third central insulating region and a third peripheral insulating region. The third central insulating region is located between the first central insulating region and the second central insulating region in the first direction. The third peripheral insulating region is located between the first peripheral insulating region and the second peripheral insulating region in the first direction. The third central insulating region has a first central portion. The first central portion includes silicon oxide. The third peripheral insulating region has a first peripheral portion and a second peripheral portion. The first peripheral portion includes silicon oxide. The second peripheral portion is located between the first peripheral portion and the second peripheral insulating region in the first direction. The second peripheral portion includes silicon oxynitride. A thickness of the first central portion in the first direction is greater than a thickness of the first peripheral portion in the first direction. The second outer circumferential portion has a thickness in the first direction greater than a thickness in the first direction of the first outer circumferential portion.
[0006] A method for manufacturing an insulating device according to an embodiment includes a first step, a second step, a third step, a fourth step, a fifth step, a sixth step, a seventh step, and an eighth step. In the first step, a first silicon oxide film is formed on a first insulating layer. The first insulating layer has a first central insulating region and a first outer peripheral insulating region. A first coil is provided inside the first central insulating region. The first outer peripheral insulating region surrounds the first central insulating region. The first silicon oxide film has a first portion and a second portion. The first portion overlaps the first central insulating region. The second portion overlaps the first outer peripheral insulating region. In the second step, a first silicon oxynitride film is formed on the first silicon oxide film. The first silicon oxynitride film has a third portion and a fourth portion. The third portion overlaps the first portion. The fourth portion overlaps the second portion. In the third step, the third portion is removed to expose the first portion. In the fourth step, a second silicon oxide film is formed on the first portion. In the fifth step, a second silicon oxynitride film is formed on the second silicon oxide film and the fourth portion. The second silicon oxynitride film has a fifth portion and a sixth portion. The fifth portion overlaps the second silicon oxide film. The sixth portion overlaps the fourth portion. In the sixth step, the fifth portion is removed to expose the second silicon oxide film. In the seventh step, a third silicon oxide film is formed on the second silicon oxide film. In the eighth step, a second insulating layer is formed on the third silicon oxide film and the sixth portion. The second insulating layer has a second central insulating region and a second outer peripheral insulating region. The second central insulating region overlaps the third silicon oxide film. A second coil is provided inside the second central insulating region. The second peripheral insulating region overlaps the sixth portion. The second peripheral insulating region surrounds the second central insulating region. [Brief description of the drawings]
[0007] [Figure 1] FIG. 1 is a plan view illustrating an insulating device according to a first embodiment. [Diagram 2] 1 is a cross-sectional view illustrating an insulating device according to a first embodiment. [Diagram 3]FIG. 6 is a cross-sectional view illustrating an insulating device according to a second embodiment. [Figure 4] FIG. 11 is a cross-sectional view illustrating an insulating device according to a third embodiment. [Diagram 5] 5(a) to 5(d) are cross-sectional views illustrating a method for manufacturing an insulating device according to the first embodiment. [Figure 6] 6(a) to 6(d) are cross-sectional views illustrating a method for manufacturing an insulating device according to the first embodiment. [Figure 7] 7(a) to 7(c) are cross-sectional views illustrating a method for manufacturing an insulating device according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Even when the same part is shown, the dimensions and ratios of each part may be different depending on the drawing. In this specification and each drawing, elements similar to those already explained are given the same reference numerals and detailed explanations are omitted as appropriate.
[0009] FIG. 1 is a plan view illustrating an insulating device according to a first embodiment. FIG. 2 is a cross-sectional view illustrating the insulating device according to the first embodiment. FIG. 2 is a cross-sectional view taken along line AA shown in FIG. The isolation device 100 according to the first embodiment is, for example, a digital isolator, a galvanic isolator, or a galvanic isolation element.
[0010] As shown in FIG. 1 and FIG. 2, the insulation device 100 includes a first circuit 1, a second circuit 2, a substrate 5, a first coil 11, a second coil 12, an insulating section 20, and a conductor 50. The insulating section 20 is provided on the substrate 5. The first coil 11 and the second coil 12 are provided inside the insulating section 20. The second coil 12 faces the first coil 11 in the Z direction. The second coil 12 is provided above the first coil 11. The conductor 50 is provided inside the insulating section 20. The conductor 50 is provided around the first coil 11 and the second coil 12.
[0011] In the description of the embodiment, an XYZ Cartesian coordinate system is used. The direction from the first coil 11 to the second coil 12 is the Z direction (first direction). Two directions that are perpendicular to the Z direction and perpendicular to each other are the X direction (second direction) and the Y direction (third direction). For the sake of explanation, the direction from the first coil 11 to the second coil 12 is called "up" and the opposite direction is called "down". These directions are based on the relative positional relationship between the first coil 11 and the second coil 12 and are unrelated to the direction of gravity. Furthermore, the first plane perpendicular to the Z direction (first direction) is a plane (XY plane) parallel to the X direction (second direction) and the Y direction (third direction).
[0012] The insulating section 20 has a first insulating layer 21, a second insulating layer 22, a third insulating layer 23, a fourth insulating layer 24, a fifth insulating layer 25, a sixth insulating layer 26, a seventh insulating layer 27, and an eighth insulating layer 28. In the insulating section 20, the first insulating layer 21, the fourth insulating layer 24, the third insulating layer 23, the fifth insulating layer 25, the second insulating layer 22, the sixth insulating layer 26, the seventh insulating layer 27, and the eighth insulating layer 28 are laminated in this order from the bottom in the Z direction. Note that the sixth to eighth insulating layers 26 to 28 are omitted in FIG. 1.
[0013] As shown in FIG. 2, a first insulating layer 21 is provided on the substrate 5. A first coil 11 is provided inside the first insulating layer 21. The first coil 11 is aligned with the first insulating layer 21 in the X direction and the Y direction. The first insulating layer 21 is in contact with the first coil 11. A fourth insulating layer 24 is provided on the first insulating layer 21 and the first coil 11. A third insulating layer 23 is provided on the fourth insulating layer 24. The fourth insulating layer 24 is located between the first insulating layer 21 and the third insulating layer 23 and between the first coil 11 and the third insulating layer 23 in the Z direction. The fourth insulating layer 24 is in contact with the first coil 11.
[0014] A fifth insulating layer 25 is provided on the third insulating layer 23. A second insulating layer 22 is provided on the fifth insulating layer 25. A second coil 12 is provided inside the second insulating layer 22 and inside the fifth insulating layer 25. The second coil 12 is aligned with the second insulating layer 22 in the X direction and the Y direction. The second insulating layer 22 is in contact with the second coil 12. The second coil 12 is aligned with the fifth insulating layer 25 in the X direction and the Y direction. The fifth insulating layer 25 is in contact with the second coil 12. The fifth insulating layer 25 is located between the second insulating layer 22 and the third insulating layer 23 in the Z direction. The third insulating layer 23 is located between the first insulating layer 21 and the second insulating layer 22 in the Z direction. The third insulating layer 23 is located between the first coil 11 and the second coil 12 in the Z direction.
[0015] A sixth insulating layer 26 is provided on the second insulating layer 22. A seventh insulating layer 27 is provided on the sixth insulating layer 26. An eighth insulating layer 28 is provided on the seventh insulating layer 27. A pad 62 connected to the second coil 12 and a pad 66 connected to a conductor 50 (described later) are provided on the seventh insulating layer 27 and the eighth insulating layer 28. The pad 62 is connected to the second circuit 2 via a wiring 63. The pad 66 is connected to a conductive member (not shown) via a wiring 67.
[0016] 1 and 2, the first coil 11 and the second coil 12 are formed in a circular spiral shape along a first surface (XY plane). The first coil 11 and the second coil 12 are not limited to a circular spiral shape, and may be formed in, for example, a rectangular spiral shape. The first coil 11 and the second coil 12 face each other in the Z direction. At least a portion of the second coil 12 is aligned with at least a portion of the first coil 11 in the Z direction.
[0017] The conductor 50 is provided around the first coil 11 and the second coil 12 along a first surface (XY plane). The conductor 50 is connected to the first coil 11, for example. The conductor 50 has a first conductive portion 51, a second conductive portion 52, and a third conductive portion 53.
[0018] The first conductive portion 51 is provided inside the first insulating layer 21. The first conductive portion 51 is provided around the first coil 11. In a plan view, the first conductive portion 51 has, for example, a circular ring shape. The first conductive portion 51 is connected to the first coil 11, for example.
[0019] The second conductive portion 52 is provided on a part of the first conductive portion 51. A plurality of second conductive portions 52 are provided along the first conductive portion 51. That is, the plurality of second conductive portions 52 are provided intermittently and spaced apart from each other along the annular first conductive portion 51. The second conductive portion 52 is provided inside the fourth insulating layer 24 and the third insulating layer 23. The second conductive portion 52 extends in the Z direction. The second conductive portion 52 has a columnar shape with the Z direction as its axis. The second conductive portion 52 has a square columnar shape with the Z direction as its axis, for example.
[0020] The third conductive portion 53 is provided on the multiple second conductive portions 52. The third conductive portion 53 is provided inside the fifth insulating layer 25 and inside the second insulating layer 22. The third conductive portion 53 is provided around the second coil 12. In a plan view, the shape of the third conductive portion 53 is the same as the shape of the first conductive portion 51. In a plan view, the shape of the third conductive portion 53 is, for example, annular. A sixth insulating layer 26 is provided on the third conductive portion 53.
[0021] 1, one end of the first coil 11 (one end of the coil) is electrically connected to the first circuit 1 via a wiring 60. The other end of the first coil 11 (the other end of the coil) is electrically connected to the first circuit 1 via a wiring 61.
[0022] One end of the second coil 12 (one end of the coil) is electrically connected to the second circuit 2 via a pad 62 and a wiring 63. The other end of the second coil 12 (the other end of the coil) is electrically connected to the second circuit 2 via a pad 64 and a wiring 65. For example, the pad 62 is provided on one end of the second coil 12. The pad 64 is provided on the other end of the second coil 12. The position of the pad 62 in the Z direction and the position of the pad 64 in the Z direction may be the same as the position of the second coil 12 in the Z direction. The pads 62 and 64 may be formed integrally with the second coil 12.
[0023] As shown in FIG. 2, a pad 66 is provided on the conductor 50. The conductor 50 is electrically connected to a conductive member (not shown) via the pad 66 and a wiring 67. For example, the conductor 50 and the substrate 5 are connected to a reference potential. The reference potential is, for example, a ground potential. The conductor 50 is connected to the reference potential, and the conductor 50 can be prevented from becoming a floating potential. This can prevent leakage of the magnetic field generated from the first coil 11 and the second coil 12, and can also prevent an external magnetic field from reaching the first coil 11 and the second coil 12.
[0024] The first circuit 1 may also be provided on the substrate 5. In this case, by providing the conductor 50 on the first circuit 1, the first circuit 1 is shielded by the conductor 50 from electromagnetic waves directed toward the first circuit 1 from outside the substrate 5 and the conductor 50. As a result, the operation of the first circuit 1 can be made more stable.
[0025] Either the first circuit 1 or the second circuit 2 is used as a transmitting circuit. The other of the first circuit 1 and the second circuit 2 is used as a receiving / transmitting circuit. Here, a case will be described in which the first circuit 1 is a transmitting / receiving circuit and the second circuit 2 is a receiving / transmitting circuit.
[0026] The first circuit 1 sends a signal (current) with a waveform suitable for transmission to the first coil 11. When the current flows through the first coil 11, a magnetic field is generated that passes through the inside of the spiral first coil 11. At least a part of the first coil 11 is aligned with at least a part of the second coil 12 in the Z direction. Some of the generated magnetic field lines pass through the inside of the second coil 12. Due to a change in the magnetic field inside the second coil 12, an induced electromotive force is generated in the second coil 12, and a current flows through the second coil 12. The second circuit 2 detects the current flowing through the second coil 12 and generates a signal according to the detection result. As a result, a signal is transmitted between the first coil 11 and the second coil 12 with the current being blocked (insulated).
[0027] Next, an example of the material of each component of the insulating device 100 will be described. The first coil 11, the second coil 12, and the conductor 50 include, for example, a metal. The first coil 11, the second coil 12, and the conductor 50 include, for example, at least one metal selected from the group consisting of copper and aluminum. In order to suppress heat generation in the first coil 11 and the second coil 12 when transmitting a signal, it is preferable that the electrical resistance of these coils is low. From the viewpoint of reducing the electrical resistance, it is preferable that the first coil 11 and the second coil 12 include copper.
[0028] The first insulating layer 21, the second insulating layer 22, the third insulating layer 23, and the seventh insulating layer 27 contain silicon and oxygen. The first insulating layer 21, the second insulating layer 22, the third insulating layer 23, and the seventh insulating layer 27 contain, for example, silicon oxide. The first insulating layer 21, the second insulating layer 22, the third insulating layer 23, and the seventh insulating layer 27 may further contain nitrogen.
[0029] The eighth insulating layer 28 contains an insulating resin such as polyimide or polyamide. The fourth insulating layer 24 and the sixth insulating layer 26 contain silicon and nitrogen. The fourth insulating layer 24 and the sixth insulating layer 26 contain, for example, silicon nitride. The substrate 5 contains silicon and an impurity. The impurity includes at least one selected from the group consisting of boron, phosphorus, arsenic, and antimony.
[0030] The fifth insulating layer 25 includes at least one selected from the group consisting of a first material including silicon and nitrogen, a second material including aluminum and oxygen, a third material including tantalum and oxygen, a fourth material including hafnium and oxygen, a fifth material including zirconium and oxygen, a sixth material including strontium, titanium, and oxygen, a seventh material including bismuth, iron, and oxygen, and an eighth material including barium, titanium, and oxygen. For example, the fifth insulating layer 25 includes silicon nitride. The relative dielectric constant of the fifth insulating layer 25 is, for example, higher than the relative dielectric constant of the third insulating layer 23. The relative dielectric constant of the fifth insulating layer 25 is, for example, higher than the relative dielectric constant of the second insulating layer 22.
[0031] The first insulating layer 21, the second insulating layer 22, and the third insulating layer 23 will be described in more detail below.
[0032] As shown in FIG. 2, the first insulating layer 21 has a first central insulating region 21a and a first outer peripheral insulating region 21b. The first central insulating region 21a is located at the center of the first insulating layer 21 in a plan view. The first central insulating region 21a includes, for example, the center of the first insulating layer 21 in a plan view. The first outer peripheral insulating region 21b is located outside the first central insulating region 21a in a plan view. The first outer peripheral insulating region 21b surrounds the first central insulating region 21a along the first surface (XY plane). That is, the first outer peripheral insulating region 21b is provided around the first central insulating region 21a in a plan view. The first coil 11 is provided inside the first central insulating region 21a.
[0033] As shown in FIG. 2, the second insulating layer 22 has a second central insulating region 22a and a second outer peripheral insulating region 22b. The second central insulating region 22a is located at the center of the second insulating layer 22 in a plan view. The second central insulating region 22a includes, for example, the center of the second insulating layer 22 in a plan view. The second outer peripheral insulating region 22b is located outside the second central insulating region 22a in a plan view. The second outer peripheral insulating region 22b surrounds the second central insulating region 22a along the first surface (XY plane). That is, the second outer peripheral insulating region 22b is provided around the second central insulating region 22a in a plan view. The second coil 12 is provided inside the second central insulating region 22a.
[0034] As shown in FIG. 2, the third insulating layer 23 has a third central insulating region 23a and a third outer peripheral insulating region 23b. The third central insulating region 23a is located at the center of the third insulating layer 23 in a plan view. The third central insulating region 23a includes, for example, the center of the third insulating layer 23 in a plan view. The third outer peripheral insulating region 23b is located outside the third central insulating region 23a in a plan view. The third outer peripheral insulating region 23b surrounds the third central insulating region 23a along the first surface (XY plane). That is, the third outer peripheral insulating region 23b is provided around the third central insulating region 23a in a plan view. The third central insulating region 23a is located between the first central insulating region 21a and the second central insulating region 22a in the Z direction. The third outer peripheral insulating region 23b is located between the first outer peripheral insulating region 21b and the second outer peripheral insulating region 22b in the Z direction.
[0035] The third central insulating region 23a has a first central portion 23a1. In the insulating device 100, the third central insulating region 23a is made of the first central portion 23a1. In the insulating device 100, the third central insulating region 23a does not have another portion (a second central portion 23a2 described below) located between the first central portion 23a1 and the second peripheral insulating region 22b in the Z direction. The first central portion 23a1 contains silicon oxide. The first central portion 23a1 is made of, for example, silicon oxide. The first central portion 23a1 is, for example, a multilayer film containing silicon oxide.
[0036] The third outer peripheral insulating region 23b has a first outer peripheral portion 23b1 and a second outer peripheral portion 23b2. The second outer peripheral portion 23b2 is located between the first outer peripheral portion 23b1 and the second outer peripheral insulating region 22b in the Z direction. The first outer peripheral portion 23b1 is located between the second outer peripheral portion 23b2 and the first outer peripheral insulating region 21b in the Z direction. The first outer peripheral portion 23b1 includes silicon oxide. The first outer peripheral portion 23b1 is made of, for example, silicon oxide. The second outer peripheral portion 23b2 includes silicon oxynitride. The second outer peripheral portion 23b2 is made of, for example, silicon oxynitride. The second outer peripheral portion 23b2 is, for example, a multilayer film including silicon oxynitride. The second outer peripheral portion 23b2 may include carbon at a concentration similar to that of an impurity. The first central portion 23a1 is aligned with the first outer peripheral portion 23b1 in the X direction and the Y direction. The first central portion 23a1 is aligned with the second outer peripheral portion 23b2 in the X and Y directions.
[0037] The thickness Ta1 of the first central portion 23a1 in the Z direction is greater than the thickness Tb1 of the first outer peripheral portion 23b1 in the Z direction. The thickness Tb2 of the second outer peripheral portion 23b2 in the Z direction is greater than the thickness Tb1. The thickness Ta1 is, for example, greater than the thickness Tb2. The thickness Ta1 is, for example, around 10 μm. The thickness Tb1 is, for example, 50 nm or more. The thickness Tb2 is, for example, around 10 μm.
[0038] As described above, in the insulating device 100, the third central insulating region 23a does not have another portion (a second central portion 23a2 described later) located between the first central portion 23a1 and the second peripheral insulating region 22b in the Z direction. That is, in the insulating device 100, the third central insulating region 23a has only the first central portion 23a1 containing silicon oxide, and does not have a portion containing silicon oxynitride. In other words, the upper end of the first central portion 23a1 is aligned with the upper end of the second peripheral portion 23b2 in the X direction and the Y direction. Also, the lower end of the first central portion 23a1 is aligned with the lower end of the first peripheral portion 23b1 in the X direction and the Y direction. The thickness Ta1 is, for example, equal to the sum of the thickness Tb1 and the thickness Tb2.
[0039] The effects of the insulating device 100 will be described below. In conventional insulating devices, a two-layered interlayer insulating film having a silicon oxide layer and a silicon oxynitride layer provided on the silicon oxide layer is formed between upper and lower electrodes. For example, in such insulating devices, increasing the proportion of silicon oxide is considered as a means for improving the insulating life. In a low electric field (for example, about 1 MV / cm), the insulating life of silicon oxide is longer than that of silicon oxynitride. Therefore, by increasing the proportion of silicon oxide, the insulating life is easily improved. However, if the silicon oxide layer is made thicker to increase the proportion of silicon oxide, the warping of the insulating device is likely to increase due to stress generated during the formation of the interlayer insulating film. In other words, in conventional insulating devices, there is a problem that it is difficult to simultaneously improve the insulating life and suppress the warping.
[0040] In the insulating device 100, the third central insulating region 23a located between the first coil 11 and the second coil 12 has a first central portion 23a1 containing silicon oxide. The third outer peripheral insulating region 23b not located between the first coil 11 and the second coil 12 has a first outer peripheral portion 23b1 containing silicon oxide and a second outer peripheral portion 23b2 containing silicon oxynitride. The thickness Ta1 of the first central portion 23a1 is larger than the thickness Tb1 of the first outer peripheral portion 23b1, and the thickness Tb2 of the second outer peripheral portion 23b2 is larger than the thickness Tb1 of the first outer peripheral portion 23b1. As a result, in the portion located between the first coil 11 and the second coil 12, the proportion of silicon oxide, which has a longer insulation life than silicon oxynitride, is increased to improve the insulation life, and in the portion not located between the first coil 11 and the second coil 12, the proportion of silicon oxynitride, which has a smaller stress than silicon oxide, is increased to suppress warping. Therefore, it is possible to improve the insulation life and suppress warping at the same time, thereby improving reliability.
[0041] Furthermore, in the insulating device 100, the thickness Ta1 of the first central portion 23a1 is greater than the thickness Tb2 of the second outer peripheral portion 23b2. This allows for a better balance between improved insulation life and suppression of warping.
[0042] In addition, in the insulating device 100, the thickness Ta1 of the first central portion 23a1 is equal to the sum of the thickness Tb1 of the first outer peripheral portion 23b1 and the thickness Tb2 of the second outer peripheral portion 23b2. That is, in the insulating device 100, the third central insulating region 23a has only the first central portion 23a1 containing silicon oxide, and has no portion containing silicon oxynitride. This allows a better balance between improved insulation life and suppression of warping.
[0043] In addition, in the insulating device 100, the first central portion 23a1 is a multilayer film containing silicon oxide. The second peripheral portion 23b2 is a multilayer film containing silicon oxynitride. This makes it possible to suppress stress when forming the first central portion 23a1 and the second peripheral portion 23b2. Therefore, warping can be further suppressed.
[0044] Second embodiment FIG. 3 is a cross-sectional view illustrating an insulating device according to the second embodiment. FIG. 3 is a cross-sectional view taken at the same position as FIG. 3, the insulating device 200 according to the second embodiment is different from the insulating device 100 in the structure of the third insulating layer 23. Other than that, the insulating device 200 is the same as the insulating device 100.
[0045] In the insulating device 200, the first central insulating region 21a of the first insulating layer 21 has a first central portion 21ax and a first intermediate portion 21ay. The first central portion 21ax is located at the center of the first central insulating region 21a in a plan view. The first central portion 21ax includes, for example, the center of the first central insulating region 21a in a plan view. The first intermediate portion 21ay is located outside the first central portion 21ax in a plan view. The first intermediate portion 21ay surrounds the first central portion 21ax along the first surface (XY plane). That is, the first intermediate portion 21ay is provided around the first central portion 21ax in a plan view. The first intermediate portion 21ay is located between the first central portion 21ax and the first outer circumferential insulating region 21b in the X direction and the Y direction. The first coil 11 is provided inside the first intermediate portion 21ay. The first central portion 21ax is a portion that is located at the center of the first spiral coil 11.
[0046] In the insulating device 200, the second central insulating region 22a of the second insulating layer 22 has a second central portion 22ax and a second intermediate portion 22ay. The second central portion 22ax is located at the center of the second central insulating region 22a in a plan view. The second central portion 22ax includes, for example, the center of the second central insulating region 22a in a plan view. The second intermediate portion 22ay is located outside the second central portion 22ax in a plan view. The second intermediate portion 22ay surrounds the second central portion 22ax along the first surface (XY plane). That is, the second intermediate portion 22ay is provided around the second central portion 22ax in a plan view. The second intermediate portion 22ay is located between the second central portion 22ax and the second outer circumferential insulating region 22b in the X direction and the Y direction. The second coil 12 is provided inside the second intermediate portion 22ay. The second central portion 22ax is a portion located at the center of the second spiral coil 12.
[0047] In the insulating device 200, the third central insulating region 23a of the third insulating layer 23 has a third central portion 23ax and a third intermediate portion 23ay. The third central portion 23ax is located at the center of the third central insulating region 23a in a planar view. The third central portion 23ax includes, for example, the center of the third central insulating region 23a in a planar view. The third intermediate portion 23ay is located outside the third central portion 23ax in a planar view. The third intermediate portion 23ay surrounds the third central portion 23ax along the first surface (XY plane). That is, the third intermediate portion 23ay is provided around the third central portion 23ax in a planar view. The third intermediate portion 23ay is located between the third central portion 23ax and the third outer circumferential insulating region 23b in the X direction and the Y direction. The third central portion 23ax is located between the first central portion 21ax and the second central portion 22ax in the Z direction. The third intermediate portion 23ay is located between the first intermediate portion 21ay and the second intermediate portion 22ay in the Z direction. In other words, the third intermediate portion 23ay overlaps with the first coil 11 and the second coil 12 in the Z direction. On the other hand, the third central portion 23ax does not overlap with the first coil 11 and the second coil 12 in the Z direction.
[0048] The third intermediate portion 23ay has a first central portion 23a1. The first central portion 23a1 includes silicon oxide. The first central portion 23a1 is made of, for example, silicon oxide. The first central portion 23a1 is, for example, a multilayer film including silicon oxide.
[0049] The third central portion 23ax has a first portion 23ax1 and a second portion 23ax2. The second portion 23ax2 is located between the first portion 23ax1 and the second intermediate portion 22ay in the Z direction. The first portion 23ax1 is located between the second portion 23ax2 and the first intermediate portion 21ay in the Z direction. The first portion 23ax1 includes silicon oxide. The first portion 23ax1 is made of, for example, silicon oxide. The second portion 23ax2 includes silicon oxynitride. The second portion 23ax2 is made of, for example, silicon oxynitride. The second portion 23ax2 is, for example, a multilayer film including silicon oxynitride. The second portion 23ax2 may include, for example, carbon at a concentration about the same as an impurity.
[0050] The thickness Ta1 in the Z direction of the first central portion 23a1 (third intermediate portion 23ay) is greater than the thickness Tb1 in the Z direction of the first outer peripheral portion 23b1. The thickness Tb2 in the Z direction of the second outer peripheral portion 23b2 is greater than the thickness Tb1. The thickness Ta1 is greater than the thickness Tb2, for example. The thickness Ta1 in the Z direction of the first central portion 23a1 (third intermediate portion 23ay) is greater than the thickness Tax1 in the Z direction of the first portion 23ax1. The thickness Tax2 in the Z direction of the second portion 23ax2 is greater than the thickness Tax1. The thickness Ta1 is greater than the thickness Tax2, for example. The thickness Tax1 is the same as the thickness Tb1, for example. The thickness Tax2 is the same as the thickness Tb2, for example.
[0051] Insulation device 200 also has an improved insulation life by increasing the proportion of silicon oxide, which has a longer insulation life than silicon oxynitride, in the portion located between first coil 11 and second coil 12, and an improved insulation life by increasing the proportion of silicon oxynitride, which has a smaller stress than silicon oxide, in the portion not located between first coil 11 and second coil 12. This allows both an improved insulation life and suppression of warping, improving reliability.
[0052] Third embodiment FIG. 4 is a cross-sectional view illustrating an insulating device according to the third embodiment. FIG. 4 is a cross-sectional view taken at the same position as FIG. 4, an insulation device 300 according to the third embodiment differs from the insulation device 100 in the structure of the third insulation layer 23. Other than that, the insulation device 300 is the same as the insulation device 100.
[0053] In the insulating device 300, the third central insulating region 23a of the third insulating layer 23 has a first central portion 23a1 and a second central portion 23a2. The second central portion 23a2 is located between the second central insulating region 22a and the first central portion 23a1 in the Z direction. The first central portion 23a1 is located between the first central insulating region 21a and the second central portion 23a2 in the Z direction. The second central portion 23a2 is aligned with the second outer peripheral portion 23b2 in the X direction and the Y direction. The second central portion 23a2 is not aligned with the first outer peripheral portion 23b1 in the X direction and the Y direction. The second central portion 23a2 includes silicon oxynitride. The second central portion 23a2 is made of, for example, silicon oxynitride. The second central portion 23a2 may include, for example, carbon at a concentration about the same as an impurity.
[0054] The thickness Ta1 of the first central portion 23a1 in the Z direction is greater than the thickness Tb1 of the first outer peripheral portion 23b1 in the Z direction. The thickness Tb2 of the second outer peripheral portion 23b2 in the Z direction is greater than the thickness Tb1. The thickness Ta1 is, for example, greater than the thickness Tb2. Furthermore, the thickness Ta1 is greater than the thickness Ta2 of the second central portion 23a2 in the Z direction. The thickness Tb2 is greater than the thickness Ta2.
[0055] Insulation device 300 also has an improved insulation life by increasing the proportion of silicon oxide, which has a longer insulation life than silicon oxynitride, in the portion located between first coil 11 and second coil 12, and an improved insulation life by increasing the proportion of silicon oxynitride, which has a smaller stress than silicon oxide, in the portion not located between first coil 11 and second coil 12. This allows both an improved insulation life and suppression of warping, improving reliability.
[0056] (Manufacturing method) 5(a) to 5(d), 6(a) to 6(d), and 7(a) to 7(c) are cross-sectional views illustrating a method for manufacturing an insulating device according to the first embodiment. As shown in Figs. 5(a) to 5(d), 6(a) to 6(d), and 7(a) to 7(c), the method for producing an insulating device according to the first embodiment includes a first step, a second step, a third step, a fourth step, a fifth step, a sixth step, a seventh step, and an eighth step. The second step is performed after the first step. The third step is performed after the second step. The fourth step is performed after the third step. The fifth step is performed after the fourth step. The sixth step is performed after the fifth step. The seventh step is performed after the sixth step. The eighth step is performed after the seventh step. Fig. 5(a) corresponds to the first and second steps. Fig. 5(b) corresponds to the third step. Figs. 5(c) and 5(d) correspond to the fourth step. Fig. 6(a) corresponds to the fifth step. Fig. 6(b) corresponds to the sixth step. Figures 6(c) and 6(d) correspond to the seventh step, and Figures 7(a) to 7(c) correspond to the eighth step.
[0057] In the first step, as shown in FIG. 5(a), a first silicon oxide film 81 is formed on the first insulating layer 21. In this example, the first silicon oxide film 81 is formed on the fourth insulating layer 24 formed on the first insulating layer 21. The first insulating layer 21 has a first central insulating region 21a and a first outer peripheral insulating region 21b. The first outer peripheral insulating region 21b surrounds the first central insulating region 21a. The first coil 11 is provided inside the first central insulating region 21a. In this example, the first conductive portion 51 is provided inside the first outer peripheral insulating region 21b. The first silicon oxide film 81 has a first portion 81a and a second portion 81b. The first portion 81a overlaps the first central insulating region 21a. The second portion 81b overlaps the first outer peripheral insulating region 21b. The first portion 81a corresponds to a part of the first central portion 23a1 described above. The second portion 81b corresponds to the above-mentioned first outer peripheral portion 23b1. The first silicon oxide film 81 is formed by, for example, CVD (Chemical Vapor Deposition). The first coil 11 is formed by, for example, plating. The first conductive portion 51 is formed by, for example, plating. The fourth insulating layer 24 is formed by, for example, CVD.
[0058] In the second step, as shown in FIG. 5(a), a first silicon oxynitride film 91 is formed on the first silicon oxide film 81. The first silicon oxynitride film 91 has a third portion 91a and a fourth portion 91b. The third portion 91a overlaps the first portion 81a. The fourth portion 91b overlaps the second portion 81b. The fourth portion 91b corresponds to a part of the second outer peripheral portion 23b2 described above. The first silicon oxynitride film 91 is formed by, for example, CVD.
[0059] 5B, in the third step, the third portion 91a is removed to expose the first portion 81a. The third portion 91a is removed by, for example, reactive ion etching (RIE).
[0060] 5(c), in the fourth step, first, a second silicon oxide film 82 is formed on the first portion 81a. In this example, the second silicon oxide film 82 is formed not only on the first portion 81a but also on the fourth portion 91b. The second silicon oxide film 82 is formed by, for example, CVD.
[0061] 5(d), in the fourth step, a portion of the second silicon oxide film 82 located above the fourth portion 91b is removed. The portion of the second silicon oxide film 82 that is not removed corresponds to a part of the first central portion 23a1 described above. The second silicon oxide film 82 is removed by, for example, chemical mechanical polishing (CMP).
[0062] In the fifth step, as shown in FIG. 6(a), a second silicon oxynitride film 92 is formed on the second silicon oxide film 82 and the fourth portion 91b. The second silicon oxynitride film 92 has a fifth portion 92a and a sixth portion 92b. The fifth portion 92a overlaps the second silicon oxide film 82. The sixth portion 92b overlaps the fourth portion 91b. The sixth portion 92b corresponds to a part of the second outer peripheral portion 23b2 described above. The second silicon oxynitride film 92 is formed by, for example, CVD.
[0063] 6B, in a sixth step, the fifth portion 92a is removed to expose the second silicon oxide film 82. The fifth portion 92a is removed by, for example, RIE.
[0064] 6(c), in the seventh step, first, a third silicon oxide film 83 is formed on the second silicon oxide film 82. In this example, the third silicon oxide film 83 is formed not only on the second silicon oxide film 82 but also on the sixth portion 92b. The third silicon oxide film 83 is formed by, for example, CVD.
[0065] 6(d), in the seventh step, a portion of the third silicon oxide film 83 located above the sixth portion 92b is removed. The portion of the third silicon oxide film 83 that is not removed corresponds to a part of the first central portion 23a1 described above. The removal of the third silicon oxide film 83 is performed by, for example, CMP.
[0066] 7(a), first, among the second portion 81b, the fourth portion 91b, the sixth portion 92b, and the fourth insulating layer 24, a portion that overlaps with the first conductive portion 51 is removed to expose the first conductive portion 51. Next, the second conductive portion 52 is formed on the first conductive portion 51. The second portion 81b, the fourth portion 91b, the sixth portion 92b, and the fourth insulating layer 24 are removed by, for example, RIE. The second conductive portion 52 is formed by, for example, plating.
[0067] In the eighth step, next, as shown in FIG. 7(b), the second insulating layer 22 is formed on the third silicon oxide film 83 and the sixth portion 92b. In this example, the second insulating layer 22 is formed on the fifth insulating layer 25 formed on the third silicon oxide film 83 and the sixth portion 92b. The second insulating layer 22 has a second central insulating region 22a and a second outer peripheral insulating region 22b. The second central insulating region 22a overlaps with the third silicon oxide film 83. The second outer peripheral insulating region 22b overlaps with the sixth portion 92b. The second outer peripheral insulating region 22b surrounds the second central insulating region 22a. The second coil 12 is provided inside the second central insulating region 22a. In this example, the third conductive portion 53 is provided inside the second outer peripheral insulating region 22b at a position overlapping with the first conductive portion 51. The second insulating layer 22 is formed by, for example, CVD. The second coil 12 is formed by, for example, plating. The third conductive portion 53 is formed by, for example, plating. The fifth insulating layer 25 is formed by, for example, CVD.
[0068] In the eighth step, next, as shown in FIG. 7(c), a sixth insulating layer 26 is formed on the second insulating layer 22. Next, a seventh insulating layer 27 is formed on the sixth insulating layer 26. Next, an eighth insulating layer 28 is formed on the seventh insulating layer 27. Next, a part of the seventh insulating layer 27 and the eighth insulating layer 28 is removed to form the pads 62 and 66. The sixth insulating layer 26 is formed by, for example, CVD. The seventh insulating layer 27 is formed by, for example, CVD. The eighth insulating layer 28 is formed by, for example, CVD. The seventh insulating layer 27 and the eighth insulating layer 28 are removed by, for example, RIE. The pads 62 and 66 are formed by, for example, sputtering.
[0069] According to the method for manufacturing an insulating device according to the embodiment, an insulating device can be easily manufactured in which the insulating life is improved by increasing the proportion of silicon oxide, which has a longer insulating life than silicon oxynitride, in the portion located between the first coil 11 and the second coil 12, and warping is suppressed by increasing the proportion of silicon oxynitride, which has a smaller stress than silicon oxide, in the portion not located between the first coil 11 and the second coil 12. Therefore, an insulating device that can improve the reliability by achieving both an improved insulating life and suppression of warping can be easily manufactured.
[0070] In the above example, the first set of forming a silicon oxynitride film, removing a portion of the silicon oxynitride film, and forming a silicon oxide film is performed in the second to fourth steps, and the second set of forming a silicon oxynitride film, removing a portion of the silicon oxynitride film, and forming a silicon oxide film is performed in the fifth to seventh steps. That is, in the above example, the set of forming a silicon oxynitride film, removing a portion of the silicon oxynitride film, and forming a silicon oxide film is performed multiple times. By performing the set of forming a silicon oxynitride film, removing a portion of the silicon oxynitride film, and forming a silicon oxide film multiple times, the thickness of the silicon oxide film or silicon oxynitride film formed per set can be reduced. This can suppress the stress when forming a silicon oxide film or silicon oxynitride film.
[0071] In the above example, this is performed twice, but in the method for manufacturing an insulating device according to the embodiment, the set of forming a silicon oxynitride film, removing a portion of the silicon oxynitride film, and forming a silicon oxide film may be performed three or more times.
[0072] According to the embodiment described above, it is possible to realize an insulating device that can achieve both an improvement in insulation life and suppression of warping.
[0073] The embodiment may include the following features.
[0074] (Configuration 1) An insulating portion; A first coil provided inside the insulating portion; a second coil provided inside the insulating portion and facing the first coil in a first direction; Equipped with the insulating section includes a first insulating layer having the first coil provided therein, a second insulating layer having the second coil provided therein, and a third insulating layer located between the first insulating layer and the second insulating layer in the first direction, the first insulating layer has a first central insulating region in which the first coil is provided, and a first outer peripheral insulating region surrounding the first central insulating region along a first plane perpendicular to the first direction, the second insulating layer has a second central insulating region in which the second coil is provided, and a second outer peripheral insulating region surrounding the second central insulating region along the first surface, the third insulating layer has a third central insulating region located between the first central insulating region and the second central insulating region in the first direction, and a third peripheral insulating region located between the first peripheral insulating region and the second peripheral insulating region in the first direction, the third central insulating region has a first central portion comprising silicon oxide; the third peripheral insulating region has a first peripheral portion including silicon oxide and a second peripheral portion located between the first peripheral portion and the second peripheral insulating region in the first direction and including silicon oxynitride; a thickness of the first central portion in the first direction is greater than a thickness of the first outer peripheral portion in the first direction; An insulating device, wherein the thickness of the second outer periphery portion in the first direction is greater than the thickness of the first outer periphery portion in the first direction.
[0075] (Configuration 2) The insulating device of configuration 1, wherein the thickness of the first central portion in the first direction is greater than the thickness of the second peripheral portion in the first direction.
[0076] (Configuration 3) An insulating device as described in configuration 1 or 2, wherein the thickness of the first central portion in the first direction is the same as the sum of the thickness of the first peripheral portion in the first direction and the thickness of the second peripheral portion in the first direction.
[0077] (Configuration 4) 4. The insulating device according to any one of configurations 1 to 3, wherein the first central portion is a multilayer film containing silicon oxide.
[0078] (Configuration 5) a first step of forming a first silicon oxide film on a first insulating layer having a first central insulating region in which a first coil is provided and a first outer peripheral insulating region surrounding the first central insulating region, the first silicon oxide film having a first portion overlapping the first central insulating region and a second portion overlapping the first outer peripheral insulating region; a second step of forming a first silicon oxynitride film on the first silicon oxide film, the first silicon oxynitride film having a third portion overlapping the first portion and a fourth portion overlapping the second portion; a third step of removing the third portion to expose the first portion; a fourth step of forming a second silicon oxide film on the first portion; a fifth step of forming a second silicon oxynitride film on the second silicon oxide film and the fourth portion, the second silicon oxide film having a fifth portion overlapping the second silicon oxide film and a sixth portion overlapping the fourth portion; a sixth step of removing the fifth portion to expose the second silicon oxide film; a seventh step of forming a third silicon oxide film on the second silicon oxide film; an eighth step of forming a second insulating layer on the third silicon oxide film and the sixth portion, the second insulating layer having a second central insulating region overlapping the third silicon oxide film and having a second coil provided therein, and a second outer peripheral insulating region overlapping the sixth portion and surrounding the second central insulating region; A method for manufacturing an insulating device comprising the steps of:
[0079] Although some embodiments of the present invention have been illustrated above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. In addition, the above-mentioned embodiments can be implemented in combination with each other. [Explanation of symbols]
[0080] 1: 1st circuit 2: 2nd circuit 5: Substrate 11: First coil 12: Second coil 20: Insulation section 21: First insulating layer 21a: First central insulating region 21ax: 1st center part 21ay: 1st middle part 21b: First outer periphery insulating region 22: Second insulating layer 22a: second central insulating region 22ax: 2nd center part 22ay: 2nd middle part 22b: Second outer perimeter insulating region 23: Third insulating layer 23a: Third central insulating region 23a1: 1st central part 23a2: 2nd central part 23ax: 3rd center part 23ax1: 1st part 23ax2: 2nd part 23ay: 3rd middle part 23b: Third outer perimeter insulating region 23b1: 1st outer peripheral part 23b2: 2nd outer peripheral part 24: Fourth insulating layer 25: 5th insulating layer 26: 6th insulating layer 27: 7th insulating layer 28: 8th insulating layer 50: Conductor 51: First conductive part 52: Second conductive part 53: Third conductive part 60, 61, 63, 65, 67: Wiring 62, 64, 66: Pad 81: First silicon oxide film 81a: Part 1 81b:Second part 82: Second silicon oxide film 83: Third silicon oxide film 91: First silicon oxynitride film 91a: 3rd part 91b: 4th part 92: Second silicon oxynitride film 92a: 5th part 92b: Part 6 100, 200, 300: Isolation devices
Claims
1. An insulating portion; A first coil provided inside the insulating portion; a second coil provided inside the insulating portion and facing the first coil in a first direction; Equipped with the insulating portion includes a first insulating layer having the first coil provided therein, a second insulating layer having the second coil provided therein, and a third insulating layer located between the first insulating layer and the second insulating layer in the first direction, the first insulating layer has a first central insulating region in which the first coil is provided, and a first outer peripheral insulating region surrounding the first central insulating region along a first plane perpendicular to the first direction, the second insulating layer has a second central insulating region in which the second coil is provided, and a second outer peripheral insulating region surrounding the second central insulating region along the first surface, the third insulating layer has a third central insulating region located between the first central insulating region and the second central insulating region in the first direction, and a third peripheral insulating region located between the first peripheral insulating region and the second peripheral insulating region in the first direction, the third central insulating region has a first central portion comprising silicon oxide; the third peripheral insulating region has a first peripheral portion including silicon oxide and a second peripheral portion located between the first peripheral portion and the second peripheral insulating region in the first direction and including silicon oxynitride; a thickness of the first central portion in the first direction is greater than a thickness of the first outer peripheral portion in the first direction; An insulating device, wherein the thickness of the second outer periphery portion in the first direction is greater than the thickness of the first outer periphery portion in the first direction.
2. The insulating device of claim 1 , wherein the first central portion has a thickness in the first direction that is greater than a thickness in the first direction of the second peripheral portion.
3. 2. The insulating device of claim 1, wherein the thickness of the first central portion in the first direction is equal to the sum of the thickness of the first peripheral portion in the first direction and the thickness of the second peripheral portion in the first direction.
4. the first central portion is a multilayer film including silicon oxide; The insulating device of claim 1 , wherein the second peripheral portion is a multilayer film including silicon oxynitride.
5. a first step of forming a first silicon oxide film on a first insulating layer having a first central insulating region in which a first coil is provided and a first outer peripheral insulating region surrounding the first central insulating region, the first silicon oxide film having a first portion overlapping the first central insulating region and a second portion overlapping the first outer peripheral insulating region; a second step of forming a first silicon oxynitride film on the first silicon oxide film, the first silicon oxynitride film having a third portion overlapping the first portion and a fourth portion overlapping the second portion; a third step of removing the third portion to expose the first portion; a fourth step of forming a second silicon oxide film on the first portion; a fifth step of forming a second silicon oxynitride film on the second silicon oxide film and the fourth portion, the second silicon oxynitride film having a fifth portion overlapping the second silicon oxide film and a sixth portion overlapping the fourth portion; a sixth step of removing the fifth portion to expose the second silicon oxide film; a seventh step of forming a third silicon oxide film on the second silicon oxide film; an eighth step of forming a second insulating layer on the third silicon oxide film and the sixth portion, the second insulating layer having a second central insulating region overlapping the third silicon oxide film and having a second coil provided therein, and a second outer peripheral insulating region overlapping the sixth portion and surrounding the second central insulating region; A method for manufacturing an insulating device comprising the steps of:
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JP2020152253A