JP2022120066A - wiring structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a passive element suitable for a mobile front end module and the like; and a manufacturing method of the passive element.

SOLUTION: A passive element 100 has: a substrate 101; first wiring 102 on the substrate; second wiring 106 above the first wiring; a first insulation film 104 located between the first wiring and the second wiring so as to make contact with the first wiring and the second wiring; and a protective film 110 on the second wiring. The protective film 110 includes: a first inorganic film 110a containing silicon nitride; a second inorganic film 110b, containing silicon oxide, which is located on the first inorganic film so as to make contact with the first inorganic film; and a third inorganic film 110c, containing silicon nitride, which is located on the second inorganic film so as to make contact with the second inorganic film.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present disclosure relates to passive devices suitable for mobile front-end modules and the like, as well as methods of making the same.

2. Description of the Related Art With the rapid spread of electronic devices having wireless communication functions, high frequency bands are being used in a large number of wireless communications. Therefore, various RF front-end modules have been developed to prevent interference during communication and ensure a sufficient communication distance. The RF front-end module incorporates various passive elements for filtering in multi-band, multi-standard communications. For example, Non-Patent Document 1 shows that integrated passive devices such as 3D inductors intended for use in RF front-end modules can be formed on through-glass substrates.

Takamasa Takano, 2 others, "3D IPD on Thur Glass Via Substrate using panel Manufacturing Technology", IMAPS 2017-50th International Symposium (IMAPS) 50th International Conference on Microelectronics), (USA), October 2017, p. 000097-000102

One of the problems of the present disclosure is to provide a passive device suitable for mobile front-end modules and the like, as well as a manufacturing method thereof.

One of the embodiments of the present disclosure is a passive device. The passive element is located between the substrate, the first wiring on the substrate, the second wiring on the first wiring, the first wiring and the second wiring, and the first wiring and the second wiring. and a protective film on the second wiring. The protective film includes a first inorganic film containing silicon nitride, a second inorganic film located on the first inorganic film and in contact with the first inorganic film and containing silicon oxide, and a second inorganic film. a third inorganic film overlying and in contact with the second inorganic film and comprising silicon nitride.

One of the embodiments of the present disclosure is a passive device. This passive element has a first surface and a second surface facing each other, a substrate provided with a through hole, and a first wiring overlapping the first surface, the second surface, and the sidewall of the through hole. , a second wiring located on the first surface via the first wiring, and a first wiring located between the first wiring and the second wiring and in contact with the first wiring and the second wiring. and a protective film on the second wiring. The protective film includes a first inorganic film containing silicon nitride, a second inorganic film located on the first inorganic film and in contact with the first inorganic film and containing silicon oxide, and a second inorganic film. a third inorganic film overlying and in contact with the second inorganic film and comprising silicon nitride.

FIG. 2 is a schematic cross-sectional view of a passive element according to one embodiment; FIG. 2 is a schematic cross-sectional view of a passive element according to one embodiment; FIG. 2 is a schematic cross-sectional view of a passive element according to one embodiment; FIG. 2 is a schematic cross-sectional view of a passive element according to one embodiment; FIG. 2 is a schematic cross-sectional view of a passive element according to one embodiment; Schematic cross-sectional views showing a method for manufacturing a passive element according to one embodiment. Schematic cross-sectional views showing a method for manufacturing a passive element according to one embodiment. Schematic cross-sectional views showing a method for manufacturing a passive element according to one embodiment.

Hereinafter, each embodiment of the present disclosure will be described with reference to the drawings and the like. However, the present disclosure can be implemented in various aspects without departing from the gist thereof, and should not be construed as being limited to the description of the embodiments illustrated below.

In order to make the description clearer, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the actual embodiment, but this is only an example and does not limit the interpretation of the present disclosure. not something to do. In this specification and each figure, elements having the same functions as those described with respect to the previous figures are denoted by the same reference numerals, and redundant description may be omitted.

In this specification and the scope of claims, when expressing a mode in which another structure is placed on top of a structure, unless otherwise specified, when simply using the notation "above" It includes both the case of arranging another structure directly above so as to be in contact with it and the case of arranging another structure above a certain structure via another structure.

In this specification and claims, the expression "a structure is exposed from another structure" means that a part of a structure is not covered by another structure. The portion not covered by the structure also includes a mode covered by another structure.

(First embodiment)
In this embodiment, a passive element 100 according to one embodiment of the present disclosure will be described.

1. Basic Structure A schematic cross-sectional view of a passive element 100 is shown in FIG. The passive element 100 includes a substrate 101, a first wiring 102 located on the substrate 101, a first insulating film 104 located on the first wiring 102 and in contact with the first wiring 102, and a first insulating film 104. It has an upper second wiring 106 and a protective film 110 positioned over the second wiring 106 . The first insulating film 104 is sandwiched between the first wiring 102 and the second wiring 106, and a capacitive element 108 is formed by this structure. The protective film 110 covers part of the first wiring 102 , part of the first insulating film 104 and part of the second wiring 106 . The protective film 110 is provided with openings overlapping with the first wiring 102 and the second wiring 106, and electrical connection with an external circuit (not shown) or the like is made through these openings. As shown in FIG. 1, the first wiring 102 and the protective film 110 may be in contact with the substrate 101 . Although not shown, another wiring may be provided on the substrate 101 . Further, the first wiring 102 may also be electrically connected to another external circuit or the like.

The substrate 101 has a function of supporting the capacitive element 108, the protective film 110, and various wirings provided thereon. Materials used for the substrate 101 include glass, silicon, gallium arsenide, gallium nitride, ceramics, and composite materials of glass and resin. Examples of resins include epoxy resins, polyimides, polyamides, and polyesters. Although not shown, an undercoat may be provided on the substrate 101 in contact with the substrate 101 . The undercoat is a film that has a function of preventing impurities such as metal ions from diffusing from the substrate 101 to the capacitive element 108, and includes, for example, silicon-containing inorganic compounds such as silicon oxide and silicon nitride. The undercoat may have a single layer structure or may be composed of multiple films containing different materials. When the undercoat is provided, the first wiring 102 and the protective film 110 are provided over the substrate 101 through the undercoat without being in direct contact with the substrate 101 .

The first wiring 102 can contain metals such as titanium, aluminum, copper, nickel, tungsten, molybdenum, gold, silver, iron, chromium, and alloys thereof, and typically contains copper. The first interconnect 102 may have a single layer structure, or may include multiple layers as shown in FIG. As will be described later, the first wiring 102 can be formed by electroplating. In this case, the seed layer 102a as the first layer and the second wiring 102a located on the seed layer 102a and in contact with the seed layer 102a. First interconnect 102 may be configured to include layer 102b. The second layer 102b contains the metals and alloys described above. The seed layer 102a contains a metal such as titanium, nickel, chromium, copper, gold, or an alloy thereof, typically copper. The seed layer 102a and the second layer 102b may have the same composition.

Since the first insulating film 104 functions as a dielectric film of the capacitor 108, it preferably contains a material with a high dielectric constant. For example, high dielectric materials such as silicon nitride, hafnium oxide, aluminum oxide, aluminum nitride, titanium oxide, barium titanate, and hafnium silicate are exemplified, and silicon nitride is a typical material due to ease of film formation. When silicon nitride is used, the first insulating film 104 can be formed by applying a chemical vapor deposition method (plasma CVD method) in the presence of plasma.

The second interconnect 106 also includes any metal or alloy that can be used in the first interconnect 102, typically copper. Further, like the first wiring 102, the second wiring 106 may also have a seed layer 106a as a first layer and a second layer 106b located on the seed layer 106a and in contact with the seed layer 106a. good. Seed layer 106a and second layer 106b include metals that can be used in seed layer 102a and second layer 102b of first interconnect 102, respectively. When the seed layer 106a is not provided, the second layer 106b is in contact with the first insulating film 104. FIG.

Although not shown, passive device 100 may further include barrier layers between seed layer 106 a and substrate 101 and/or between seed layer 106 a and first insulating film 104 . The material included in the barrier layer is selected from metals such as titanium, tantalum, molybdenum, and tungsten, alloys thereof, and nitrides thereof, and has a higher melting point than the metals included in the first wiring 102 and the second wiring 106. It is preferably a conductive material having By providing the barrier layer, the metal contained in the first wiring 102 and the second wiring 106 can be prevented from diffusing.

The structure of the protective film 110 can be arbitrarily selected, and can have, for example, a three-layer structure. When the protective film 110 has a three-layer structure, the protective film 110 includes a first inorganic film 110a, a second inorganic film 110b located on the first inorganic film 110a and in contact with the first inorganic film 110a, and a second inorganic film 110b. It is composed of a third inorganic film 110c located on the film 110b and in contact with the second inorganic film 110b. The protective film 110 is provided so as to be in contact with the second wiring 106 .

The dielectric constant of the second inorganic film 110b is preferably smaller than that of the first inorganic film 110a and the third inorganic film 110c. More specifically, the first inorganic film 110a and the third inorganic film 110c contain silicon nitride or silicon carbide. That is, the first inorganic film 110a and the third inorganic film 110c contain silicon and nitrogen or silicon and carbon as main constituent elements. On the other hand, the second inorganic film 110b contains silicon oxide or silicon oxynitride. That is, the second inorganic film 110b contains silicon and oxygen as constituent elements, and may further contain nitrogen. When nitrogen is included, its composition is smaller than that of oxygen. These first inorganic film 110a, second inorganic film 110b, and third inorganic film 110c are formed by plasma CVD.

The third inorganic film 110c can be configured to have a thickness greater than the thickness of the first inorganic film 110a and less than the thickness of the second inorganic film 110b. That is, when the thicknesses of the first inorganic film 110a, the second inorganic film 110b, and the third inorganic film 110c are T ₁ , T ₂ , and T ₃ respectively, the protective film 110 is formed so that the following relationship holds. Can be configured.
_T1 < _T3 < _T2

For example, the thickness of the first inorganic film 110a can be 0.05 μm or more and 0.3 μm or less, typically 0.2 μm. The thickness of the second inorganic film 110b can be 0.5 μm or more and 10 μm or less, or 1 μm or more and 5 μm or less. The thickness of the third inorganic film 110c can be 0.2 μm or more and 1 μm or less, or 0.3 μm or more and 0.7 μm or less, typically 0.5 μm.

The silicon oxide contained in the second inorganic film 110b has relatively high hydrophilicity. Therefore, when the third inorganic film 110c is not provided, impurities such as water enter from the outside and diffuse into the first inorganic film 110a. Although the first inorganic film 110a contains silicon nitride, which has a low hydrophilicity and a high blocking property against impurities, if the thickness is small, the impurities partially permeate. Therefore, the surfaces of the first wiring 102 and the second wiring 106 are oxidized by water and impurities contained in the water. The adhesion between 106 and the first insulating film is lowered, and peeling occurs therebetween. When such peeling occurs, a leakage current is generated, and the function of the capacitor 108 is significantly deteriorated.

However, the passive device 100 can comprise a third inorganic film 110c containing silicon nitride, having a greater thickness than the first inorganic film 110a, on the second inorganic film 110b. With such a configuration, the speed at which impurities penetrate into the first inorganic film 110a through the second inorganic film 110b can be significantly reduced, and as a result, the gap between the first wiring 102 and the first insulating film 104 can be reduced. peeling and peeling between the first insulating film 104 and the second wiring 106 can be effectively prevented.

As described above, the protective film 110 does not necessarily have a three-layer structure. It may have a structure. In this case, the third inorganic film 110 c is provided so as to be in contact with the second wiring 106 .

2. Variations The structural features described above can also be applied to various forms of passive devices. Passive elements 120, 130, and 140 having different structures from the passive element 100 will be described below as passive elements according to the present embodiment.

Passive element 120 shown in FIG. is provided, and the structure is different from that of the passive element 100 in that the second wiring 106 and the third wiring 124 are electrically connected through this opening. An opening provided in the protective film 110 exposes the third wiring 124, and electrical connection with other external circuits or the like is made through this opening.

The second insulating film 122 is partially sandwiched between the second wiring 106 and the protective film 110 so as to bury the first wiring 102, the second wiring 106, and the first insulating film 104. be provided. That is, the second insulating film 122 is formed so as to be in contact with the top surface of the first insulating film 104 and the top surface of the second wiring 106 .

The second insulating film 122 contains an organic compound. The organic compound used preferably has a low dielectric ^constant and a low dielectric loss ^tangent . An organic compound of 10 ⁻³ or more and 1×10 ⁻² or less can be used as the second insulating film 122 . Such an organic compound is typically a polymer having a polyimide as a basic skeleton (hereinafter simply referred to as polyimide), and polyimide may be chain-like or may be crosslinked between molecules. Epoxy resin, fine particles of silicon oxide, glass fiber, or the like may be mixed into the second insulating film 122 . The second insulating film 122 may have flexibility.

Third interconnect 124 includes metals and alloys that can be used in first interconnect 102 and second interconnect 106 . Like the first wiring 102 and the second wiring 106, the third wiring 124 may also have a multilayer structure. For example, as shown in FIG. 2A, the third wiring 124 may include a seed layer 124a as a first layer and a second layer 124b located on the seed layer 124a and in contact with the seed layer 124a. good. The seed layer 124a and the second layer 124b can have the same configurations as the seed layers 102a, 106a and the second layers 102b, 106b of the first wiring 102 and the second wiring 106, respectively. Although not shown, a barrier layer may be provided between the seed layer 124 a and the second wiring 106 .

Part of the first insulating film 104 may be in contact with the side surface of the first wiring 102 and the top surface of the substrate 101 as shown in FIG. 2B. When an undercoat is provided, the first insulating film 104 may be in contact with the undercoat.

The passive element 128 shown in FIG. 3 has a structure similar to that of the passive element 100 in that it has the second insulating film 122 and the second wiring 106 is arranged so as to cover at least a part of the protective film 110 . different. The second wiring 106 is in contact with the first insulating film 104 through openings provided in the protective film 110 and the second insulating film 122 .

The passive element 130 shown in FIG. 4 differs from the passive element 120 in that the relationship between the upper limits of the third wiring 124 and the protective film 110 is different. More specifically, in the passive element 130 , the third wiring 124 is located on the protective film 110 and is in contact with the protective film 110 . Furthermore, the third wiring 124 is in contact with the second wiring 106 through the opening provided in the protective film 110 . As an optional configuration, the passive element 130 may have a third insulating film 126 located on the third wiring 124 and in contact with the third wiring 124 . The third insulating film 126 also has an opening, through which the third wiring is exposed and connected to another wiring. The third insulating film 126 also contains an organic compound, and this organic compound may have the same composition as the organic compound contained in the second insulating film 122 .

As described above, since the second insulating film 122 and the third insulating film 126 contain an organic compound, their coefficients of thermal expansion are 50 ppm or more. Further, since the coefficient of thermal expansion of the metal forming the first wiring 102, the second wiring 106, and the third wiring 124 is also 10 ppm or more, the heat treatment in the manufacturing process of the passive element causes the heat treatment in the first insulating film 104. stress remains. On the other hand, the coefficient of thermal expansion of the first insulating film 104 is 0.1 ppm to 0.5 ppm, which is approximately the same as that of the protective film 110 . Therefore, by arranging the protective film 110 on the second insulating film 122, the second wiring 106, or the third wiring 124 as in the structure shown in this embodiment, the inside of the first insulating film 104 can be reduced. It is possible to reduce the residual stress of As a result, peeling between the first insulating film 104 and the first wiring 102 and peeling between the first insulating film 104 and the second wiring 106 can be prevented. Capacitor element 108 having stable characteristics can be obtained.

The passive element 140 shown in FIG. 5 has one or more through-holes 142 in the substrate 101, and the first wiring 102 is part of the upper surface (first surface) of the substrate 101. The structure differs from that of the passive element 120 in that it covers a part of the opposing lower surface (second surface) and at least part of the side wall of the through hole 142 . The first wiring 102 functions as a through wiring penetrating the substrate 101 . The through hole 142 is provided with not only the first wiring 102 but also the through electrode 144 . Like the first wiring 102 and the second wiring 106, the through electrode 144 can also have a seed layer 144a as a first layer and a second layer 144b overlapping the seed layer 144a. A filler 146 containing an organic compound such as epoxy resin, acrylic resin, polyimide, polyamide, polyester, or titanium or copper may be further disposed in the through hole 142 . When filling with an organic compound, an inorganic material such as silica may be mixed with the organic compound. Although not shown, the passive element 140 may be configured such that the through hole 142 is filled with the second layer 102b of the first wiring 102 without placing the filler 146 thereon. Further, between the seed layer 102a and the substrate 101, one or more layers of an insulating film containing an organic compound such as polyimide or polyamide or an inorganic compound such as silicon oxide or silicon nitride may be provided. This insulating film also functions as an undercoat.

Furthermore, as an optional configuration, a second protective film 148 may be provided on the second surface of the substrate 101 . The second protective film 148 can contain the same material as the second insulating film 122 . When the second protective film 148 is provided, the second protective film 148 is provided with an opening that exposes the first wiring 102 and an opening that partially exposes the through electrode 144 .

By adopting such a configuration, electrical connection between the passive element 140 and an external circuit or the like can be easily achieved.

In passive elements such as high-frequency elements that require high operating frequencies, the insulating film surrounding the wiring of the passive elements is required to have a low dielectric constant and dielectric loss tangent in order to prevent signal transmission loss and delay. Even if the insulating film (for example, the second insulating film 122 in the passive element 100) is formed using a material that satisfies such performance, impurities such as water, oxygen, and metal ions are introduced from the outside after the passive element is formed. penetrates into the insulating film, and the dielectric constant and dielectric loss tangent of the insulating film gradually increase. As a result, signal transmission loss or delay occurs, which greatly affects the characteristics of the passive element.

On the other hand, in the passive elements 120, 130, and 140, the upper surface of the second insulating film 122 covering the first wiring 102 and the second wiring 106 is covered with the protective film 110 having a three-layer structure. As described above, when the third inorganic film 110c does not exist, the silicon oxide contained in the second inorganic film 110b has relatively high hydrophilicity. It diffuses inside the inorganic film 110a. When the thickness of the first inorganic film 110a is small, some impurities are transmitted. Therefore, impurities penetrate into the second insulating film 122, and the dielectric constant and dielectric loss tangent of the second insulating film 122 increase.

However, as described above, the protective film 110 is provided with the third inorganic film 110c having a relatively large thickness. The rate at which impurities penetrate into the film 122 can be greatly reduced, and the increase in the dielectric constant and dielectric loss tangent of the second insulating film 122 can be suppressed. Therefore, the passive element 100 can function as a high frequency device driven at a high frequency.

(Second embodiment)
In this embodiment, the method for manufacturing the passive element described in the first embodiment will be described by exemplifying the passive element 140 . Descriptions of configurations similar to or similar to those described in the first embodiment may be omitted.

First, through holes 142 are formed in the substrate 101 (FIG. 6A). When a glass substrate is used as the substrate 101, the through holes 142 may be formed by etching such as plasma etching or wet etching, laser irradiation, or mechanical processing such as sandblasting or ultrasonic drilling. The number and size of through-holes 142 can be arbitrarily determined according to the design of passive element 140 . After that, seed layers 102 a and 144 a are formed to cover at least part of the side walls of through hole 142 and part of both surfaces (first surface and second surface) of substrate 101 . The seed layers 102a and 144a can be formed by sputtering, CVD, electroless plating, vapor deposition, or the like. In particular, by applying the sputtering method, the seed layers 102a and 144a are efficiently formed. Although not shown, an insulating film containing an organic compound such as polyimide or polyamide or an inorganic compound such as silicon oxide or silicon nitride is formed on the sidewalls of the through hole 142 and both surfaces of the substrate 101 before forming the seed layers 102a and 144a. , or multiple layers may be formed.

Next, a resist mask 150 is formed on the first and second surfaces of the substrate 101 to protect regions where the first wiring 102 and the through electrode 144 are not formed (FIG. 6A). The resist mask 150 may be formed by applying and curing a liquid resist, but since the substrate 101 has the through holes 142, a film-like resist is applied to the first surface and the second surface. It can be efficiently formed by pasting, and then performing exposure and development.

After that, electric power is supplied to the seed layers 102a and 144a to perform electroplating, a metal film is formed on the seed layers 102a and 144a not covered with the resist mask 150, the second layer 102b of the first wiring 102, and A second layer 144b of the through electrode 144 is formed. After that, the resist mask 150 is removed (FIG. 6B), and the seed layers 102a and 144b exposed from the second layers 102b and 144b are removed by etching, thereby forming the first wiring 102 and the through electrode 144. (Fig. 6(C)). As an etchant, an etchant containing an acid such as sulfuric acid can be used. Although not shown, other wiring may be formed on the first surface or the second surface of the substrate 101 prior to forming the through hole 142, the first wiring 102, and the through electrode 144. FIG.

Next, the inside of the through-hole 142 is filled with a filler 146 (FIG. 6(C)). For example, the filling material 146 can be formed by applying epoxy resin, acrylic resin, polyimide, or a precursor thereof by an inkjet method, a printing method, a spin coating method, or the like so as to fill the through holes 142 and then curing the resin. can.

Subsequently, a first insulating film 104 is formed over the first wiring 102 (FIG. 6D). As described above, the first insulating film 104 typically contains silicon nitride and can be formed by applying the plasma CVD method. After that, a seed layer 106a is formed so as to cover the through electrode 144, the filling material 146, the first wiring 102, and the first insulating film 104 (FIG. 6D). Although not shown, a barrier layer may be formed before forming the seed layer 106a. In this case, for example, a barrier layer containing titanium can be formed with a thickness of 0.1 μm, and a seed layer 106a containing copper can be formed with a thickness of 0.2 μm. The seed layer 106a and the barrier layer are formed using a CVD method, a sputtering method, an electroless plating method, a vapor deposition method, or the like.

Next, a resist mask 152 is formed in a region where the second wiring 106 is not formed, power is supplied to the seed layer 106a, and electrolytic plating is performed to form the second layer 106b of the second wiring 106 (FIG. 7A). )). After that, the resist mask 152 is removed, and the seed layer 106a exposed from the second layer 106b is removed by etching (FIG. 7B).

Subsequently, a second insulating film 122 is formed so as to cover part of the first wiring 102, the first insulating film 104, and the second wiring 106 (FIG. 7C). Specifically, the photosensitive polymer such as polyimide described in the first embodiment, or a solution or suspension of its precursor is applied onto the substrate 101, and then exposed using a photomask, developed, and baked. Thus, a second insulating film 122 having an opening exposing the second wiring 106 is formed. Alternatively, the second insulating film 122 may be formed by attaching the above polymer film and performing exposure, development, and baking using a photomask. The thickness of the second insulating film 122 is appropriately adjusted within the range of 0.5 μm to 5 μm.

After that, a second layer 124b is formed through the seed layer 124a by the same method as the formation of the seed layer 106a and the second layer 106b, thereby forming the third wiring 124 (see FIG. 8 ( A)).

Subsequently, a protective film 110 is formed. The protective film 110 is formed by sequentially forming a first inorganic film 110a, a second inorganic film 110b, and a third inorganic film 110c using a plasma CVD method (FIG. 8B). After that, plasma etching is performed on the protective film 110 to form an opening that overlaps with the third wiring 124 . As a result, part of the third wiring 124 is exposed from the protective film 110 (FIG. 8C). For plasma etching, fluorine-containing alkanes such as CF ₄ and CHF ₄ and alkenes may be used.

In this example, the results of a reliability test performed on the passive element of the first embodiment will be described. The passive element used was the passive element 140 (see FIG. 5), and the seed layer 102a was formed to a thickness of 0.1 μm using an electroless plating method. The thickness of the first insulating film 104 was 0.1 μm. A barrier layer containing titanium (thickness: 0.1 μm) and a seed layer 106a containing copper (thickness: 0.2 μm) were formed on the first insulating film 104 by sputtering. Similarly, a barrier layer containing titanium (0.1 μm thick) and a seed layer 124a containing copper (0.2 μm thick) were formed on the second wiring 106 as well. The first inorganic film 110a, the second inorganic film 110b, and the third inorganic film 110c of the protective film 110 are all formed by plasma CVD, and have thicknesses of 0.2 μm, 1.0 μm, and 0.2 μm, respectively. 0.4 μm.

The fabricated passive device was allowed to stand for 96 hours under conditions of a temperature of 130° C. and a humidity of 85%, and then cross-sectionally observed using a scanning electron microscope. As a result, no peeling was observed between the first wiring 102 and the first insulating film 104 and between the second wiring 106 and the first insulating film 104 . As a result of measuring the capacitance of the capacitive element 108 formed by the first wiring 102, the first insulating film 104, and the second wiring 106, it was confirmed that substantially the same capacitance value as the design value was obtained.

On the other hand, as a comparative example, when a passive element having a structure similar to that of the passive element 140 but not having the protective film 110 is used, a It was found that peeling occurred between the wiring 106 and the first insulating film 104 . It was also confirmed that the first wiring 102 and the second wiring 106 were oxidized. As a result of measuring the capacitance of the capacitor 108, the leak current was very large, and the capacitance value could not be obtained.

As shown in the above examples, it was confirmed that it is possible to provide a highly reliable passive device by applying the protective film 110 having a three-layer structure.

Each of the embodiments described above as embodiments of the present disclosure can be implemented in combination as appropriate as long as they do not contradict each other. In addition, based on each embodiment, addition, deletion, or design change of constituent elements as appropriate by those skilled in the art is also included in the scope of the present disclosure as long as it includes the gist of the present disclosure.

In addition, even if there are other effects that are different from the effects brought about by each of the above-described embodiments, those that are obvious from the description of this specification or those that can be easily predicted by those skilled in the art are of course It is understood that provided by the present disclosure.

100: passive element, 101: substrate, 102: first wiring, 102a: seed layer, 102b: second layer, 104: first insulating film, 106: second wiring, 106a: seed layer, 106b: Second layer, 108: capacitive element, 110: protective film, 110a: first inorganic film, 110b: second inorganic film, 110c: third inorganic film, 120: passive element, 122: second insulation Film 124: Third wiring 124a: Seed layer 124b: Second layer 126: Third insulating film 128: Passive element 130: Passive element 140: Passive element 142: Through hole 144 : through electrode, 144a: seed layer, 144b: second layer, 146: filling material, 148: second protective film, 150: resist mask, 152: resist mask,

Claims (1)

substrate,
a first wiring on the substrate;
a second wire on the first wire;
a first insulating film located between the first wiring and the second wiring and in contact with the first wiring and the second wiring; and a protective film on the second wiring,
The protective film is
a first inorganic film comprising silicon nitride;
a second inorganic film positioned on the first inorganic film and in contact with the first inorganic film and containing silicon oxide; and a second inorganic film positioned on the second inorganic film and in contact with the first inorganic film. and including a third inorganic film comprising silicon nitride.

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