JP7087618B2 - Passive element - Google Patents

Description

The present disclosure relates to a passive element suitable for a mobile front-end module and the like, and a method for manufacturing the same.

With the rapid spread of electronic devices having wireless communication functions, high frequency bands are being used in an extremely large number of wireless communications. Therefore, various RF front-end modules have been developed in order to prevent interference during communication and secure 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 an integrated passive element such as a 3D inductor intended to be used in an RF front-end module can be formed on a glass-through wiring board.

Takamasa Takamasa (Takamasa Takano), 2 outsiders "3D IPD (3D IPD on Thur Glass Via Substrate processing panel Manufacturing MachineSonicSonicSonicSonicSonicSonicSonicSonicSonicSonicSonicSonicSonicSonicSonicSonicSonicSonicSonicSonicSonicSonicS) 50th International Conference on Microelectronics), (USA), October 2017, p. 00977-000102

One of the objects of the present disclosure is to provide a passive element suitable for a mobile front-end module or the like, and a method for manufacturing the passive element.

One of the embodiments of the present disclosure is a passive element. This passive element is located between the substrate, the first wiring on the substrate, the second wiring on the first wiring, and the first wiring and the second wiring, and the first wiring and the second wiring. It has a first insulating film in contact with the wiring of the above and a protective film on the second wiring. The protective film is located on the first inorganic film containing silicon nitride and the first inorganic film, is in contact with the first inorganic film, and has a second inorganic film containing silicon oxide and a second inorganic film. It is located above and is in contact with the second inorganic film and contains a third inorganic film containing silicon nitride.

One of the embodiments of the present disclosure is a passive element. This passive element has a first surface and a second surface facing each other, a substrate having a through hole, and a first wiring overlapping the first surface, the second surface, and the side wall of the through hole. , A first wiring located between the first wiring and the second wiring and in contact with the first wiring and the second wiring, and the second wiring located on the first surface via the first wiring. It has an insulating film of the above and a protective film on the second wiring. The protective film is located on the first inorganic film containing silicon nitride and the first inorganic film, is in contact with the first inorganic film, and has a second inorganic film containing silicon oxide and a second inorganic film. It is located above and is in contact with the second inorganic film and contains a third inorganic film containing silicon nitride.

Schematic cross-sectional view of a passive element according to one of the embodiments. Schematic cross-sectional view of a passive element according to one of the embodiments. Schematic cross-sectional view of a passive element according to one of the embodiments. Schematic cross-sectional view of a passive element according to one of the embodiments. Schematic cross-sectional view of a passive element according to one of the embodiments. A schematic cross-sectional view showing a method of manufacturing a passive element according to one of the embodiments. A schematic cross-sectional view showing a method of manufacturing a passive element according to one of the embodiments. A schematic cross-sectional view showing a method of manufacturing a passive element according to one of the embodiments.

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

The drawings may schematically represent the width, thickness, shape, etc. of each part as compared to the actual embodiment in order to clarify the explanation, but this is merely an example and the interpretation of the present disclosure is limited. It's not something to do. In this specification and each figure, elements having the same functions as those described with respect to the above-mentioned figures may be designated by the same reference numerals to omit duplicate explanations.

In the present specification and the scope of patent claims, when expressing an aspect of arranging another structure on one structure, when the term "above" is simply used, the structure shall be used unless otherwise specified. It includes both the case where another structure is placed directly above the structure so as to be in contact with each other and the case where another structure is placed above one structure via another structure.

In the present specification and claims, the expression "a structure is exposed from another structure" means an aspect in which a part of one structure is not covered by another structure, and other structures are used. The portion not covered by the structure also includes an embodiment covered by yet another structure.

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

1. 1. Basic structure FIG. 1 shows a schematic cross-sectional view of the passive element 100. The passive element 100 is located on the substrate 101, the first wiring 102 located on the substrate 101, and the first insulating film 104, which is located on the first wiring 102 and is in contact with the first wiring 102. It has a second wiring 106 above, and a protective film 110 located on the second wiring 106. The first insulating film 104 is sandwiched between the first wiring 102 and the second wiring 106, and the capacitive element 108 is formed by this structure. The protective film 110 covers a part of the first wiring 102, a part of the first insulating film 104, and a part of the second wiring 106. The protective film 110 is provided with an opening that overlaps with the first wiring 102 and the second wiring 106, and an electrical connection with an external circuit (not shown) or the like is made through the opening. 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 on the substrate 101. Examples of the material used for the substrate 101 include glass, silicon, gallium arsenide, gallium nitride, ceramics, and a composite material of glass and resin. Examples of the resin include epoxy resin, polyimide, polyamide, polyester and the like. Although not shown, an undercoat in contact with the substrate 101 may be provided on the substrate 101. The undercoat is a film having a function of preventing impurities such as metal ions from diffusing from the substrate 101 to the capacitive element 108 or the like, and contains a silicon-containing inorganic compound such as silicon oxide or silicon nitride. The undercoat may have a single layer structure or may be composed of a plurality of films containing different materials. When the undercoat is provided, the first wiring 102 and the protective film 110 are not directly in contact with the substrate 101, but are provided on the substrate 101 via the undercoat.

The first wiring 102 can include metals such as titanium, aluminum, copper, nickel, tungsten, molybdenum, gold, silver, iron, chromium and alloys thereof, and typically contains copper. The first wiring 102 may have a single-layer structure, or may include a plurality of layers as shown in FIG. As will be described later, the first wiring 102 can be formed by an electrolytic plating method, and in this case, the second wiring 102 is located on the seed layer 102a and the seed layer 102a as the first layer and is in contact with the seed layer 102a. The first wiring 102 can be configured to include the layer 102b. The second layer 102b contains the above-mentioned metals and alloys. The seed layer 102a contains a metal such as titanium, nickel, chromium, copper, gold, or an alloy thereof, and typically contains 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 capacitive element 108, it is preferable to contain a material having a high dielectric constant. For example, high dielectrics 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 because of the 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 wiring 106 also contains the metals and alloys that can be used in the first wiring 102, typically copper. Further, even if the second wiring 106 is located on the seed layer 106a and the seed layer 106a as the first layer and has the second layer 106b in contact with the seed layer 106a, like the first wiring 102. good. The seed layer 106a and the second layer 106b contain metals that can be used in the seed layer 102a and the second layer 102b of the first wiring 102, respectively. When the seed layer 106a is not provided, the second layer 106b is in contact with the first insulating film 104.

Although not shown, the passive element 100 may further have a barrier layer between the seed layer 106a and the substrate 101 and / or between the seed layer 106a and the first insulating film 104. The material contained in the barrier layer is selected from metals such as titanium, tantalum, molybdenum, and tungsten, alloys thereof, or nitrides thereof, and has a higher melting point than the metal contained in the first wiring 102 and the second wiring 106. It is preferable that it is a conductive material having. By providing the barrier layer, it is possible to prevent the metal contained in the first wiring 102 and the second wiring 106 from diffusing.

The structure of the protective film 110 can be arbitrarily selected, and can have, for example, a three-layer structure. When having a three-layer structure, the protective film 110 is located on the first inorganic film 110a, the first inorganic film 110a, and is in contact with the first inorganic film 110a, the second inorganic film 110b, and the second inorganic film. 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 (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 nitride. That is, the second inorganic film 110b contains silicon and oxygen as constituent elements, and may further contain nitrogen. When it contains nitrogen, its composition is smaller than that of oxygen. The first inorganic film 110a, the second inorganic film 110b, and the third inorganic film 110c are formed by a plasma CVD method.

The thickness of the third inorganic film 110c can be configured to be larger than the thickness of the first inorganic film 110a and smaller than the thickness of the second inorganic film 110b. That is, assuming that 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 provided so that the following relationship is established. Can be configured.
T ₁ <T ₃ <T ₂

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 is relatively hydrophilic. Therefore, when the third inorganic film 110c is not provided, impurities such as water invade from the outside and the impurities diffuse into the first inorganic film 110a. The first inorganic film 110a contains silicon nitride having low hydrophilicity and high blocking property against impurities, but when the thickness is small, some impurities permeate. Therefore, the surface of the first wiring 102 and the second wiring 106 is oxidized by water and impurities contained therein, and as a result, the second wiring between the first wiring 102 and the first insulating film 104 The adhesion between the 106 and the first insulating film is reduced, and peeling occurs between them. When such peeling occurs, a leak current is generated, and the function of the capacitive element 108 is significantly deteriorated.

However, the passive element 100 can include a third inorganic film 110c on the second inorganic film 110b, which has a thickness larger than that of the first inorganic film 110a and contains silicon nitride. In such a configuration, the rate at which impurities infiltrate into the first inorganic film 110a through the second inorganic film 110b can be significantly reduced, and as a result, between the first wiring 102 and the first insulating film 104. 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 to have a three-layer structure. For example, when used in the atmosphere where the water concentration is low, the protective film 110 is a single layer composed of a third inorganic film 110c. It may have a structure. In this case, the third inorganic film 110c is provided so as to be in contact with the second wiring 106.

2. 2. Modifications The structural features described above can also be applied to various forms of passive devices. Hereinafter, as passive elements according to the present embodiment, passive elements 120, 130, and 140 having a structure different from that of the passive element 100 will be described.

The passive element 120 shown in FIG. 2A further has a second insulating film 122 and a third wiring 124, and an opening in the second insulating film 122 that overlaps with the second wiring 106. 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. The opening provided in the protective film 110 exposes the third wiring 124, and an electrical connection with another external circuit or the like is made through this opening.

A part of the second insulating film 122 is sandwiched between the second wiring 106 and the protective film 110 so as to embed the first wiring 102, the second wiring 106, and the first insulating film 104. It will be provided. That is, the second insulating film 122 is formed so as to be in contact with the upper surface of the first insulating film 104 and the upper 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 dielectric loss tangent, for example, a dielectric constant of 2.0 or more and 4.0 or less, and a dielectric loss tangent of 1 × 10 ^-4 or more and 1 × 10 ⁻² or less, or 1 ×. 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 the polyimide may be in the form of a chain or may be crosslinked between molecules. Epoxy resin, fine particles of silicon oxide, glass fiber, or the like may be mixed with the second insulating film 122. The second insulating film 122 may have flexibility.

The third wiring 124 contains a metal or alloy that can be used in the first wiring 102 and the second wiring 106. Like the first wiring 102 and the second wiring 106, the third wiring 124 may have a multi-layer structure. For example, as shown in FIG. 2A, the third wiring 124 may include a second layer 124a located above the seed layer 124a and the seed layer 124a as the first layer 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 and 106a of the first wiring 102 and the second wiring 106, and the second layers 102b and 106b, respectively. Although not shown, a barrier layer may be provided between the seed layer 124a and the second wiring 106.

As shown in FIG. 2B, the first insulating film 104 may partially come into contact with the side surface of the first wiring 102 or the upper surface of the substrate 101. When the 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 a second insulating film 122 and a 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 at the openings provided in the protective film 110 and the second insulating film 122.

The passive element 130 shown in FIG. 4 is different from the passive element 120 in that the upper limit relationship between 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. Further, the third wiring 124 is in contact with the second wiring 106 at the opening provided in the protective film 110. As an arbitrary 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, in which the third wiring is exposed and is connected to other 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, the coefficient of thermal expansion thereof is 50 ppm or more. Further, since the coefficient of thermal expansion of the metal constituting the first wiring 102, the second wiring 106, and the third wiring 124 is 10 ppm or more, the heat treatment in the manufacturing process of the passive element causes the inside of the first insulating film 104. Remains stress. 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 about the same as that of the protective film 110. Therefore, as in the structure shown in the present embodiment, by arranging the protective film 110 on the second insulating film 122, the second wiring 106, or the third wiring 124, the inside of the first insulating film 104 It is possible to reduce the residual stress of the. As a result, it is possible to prevent the peeling between the first insulating film 104 and the first wiring 102 and the peeling between the first insulating film 104 and the second wiring 106, and the generation of leakage current is suppressed. A capacitive element 108 having stable characteristics can be obtained.

In the passive element 140 shown in FIG. 5, one or a plurality of through holes 142 are provided in the substrate 101, and the first wiring 102 is a part or upper surface 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 facing lower surface (second surface) and at least a part of the side wall of the through hole 142. The first wiring 102 functions as a through wiring that penetrates the substrate 101. The through hole 142 is provided with a through electrode 144 as well as the first wiring 102. Similar to the first wiring 102 and the second wiring 106, the through electrode 144 can also have the seed layer 144a as the first layer and the second layer 144b overlapping the seed layer 144a. Further, an organic compound such as an epoxy resin, an acrylic resin, a polyimide, a polyamide, or a polyester, or a filler 146 containing titanium or copper may be arranged in the through hole 142. When filling 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 so that the filler 146 is not arranged and the through hole 142 is filled with the second layer 102b of the first wiring 102. Further, one or a plurality of insulating films containing an organic compound such as polyimide or polyamide or an inorganic compound such as silicon oxide or silicon nitride may be provided between the seed layer 102a and the substrate 101. This insulating film also functions as an undercoat.

Further, as an arbitrary configuration, the 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 exposes a part of the through electrode 144.

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

In a passive element such as a high-frequency element, which requires a high operating frequency, a low dielectric constant and a dielectric loss tangent are required for the insulating film surrounding the wiring of the passive element in order to prevent signal transmission loss and delay. Even when an insulating film (for example, the second insulating film 122 in the passive element 100) is formed using a material satisfying such performance, impurities such as water, oxygen, and metal ions are externally formed after the passive element is formed. Invades the insulating film, and the dielectric constant and dielectric loss tangent of the insulating film gradually increase. As a result, signal transmission loss and delay occur, 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 that covers 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 is relatively hydrophilic, so that when impurities such as water invade from the outside, the impurities become the first. It diffuses into the inorganic film 110a. When the thickness of the first inorganic film 110a is small, some impurities are transmitted. Therefore, impurities invade the second insulating film 122, and the dielectric constant and the dielectric loss tangent of the second insulating film 122 increase.

However, as described above, since the protective film 110 is provided with the third inorganic film 110c having a relatively large thickness, the first inorganic film 110a and the second insulating film pass through the second inorganic film 110b. The rate at which impurities infiltrate into the film 122 can be significantly reduced, and an 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 of manufacturing the passive element described in the first embodiment will be described by exemplifying the passive element 140. The description may be omitted for the configuration similar to or similar to the configuration described in the first embodiment.

First, a through hole 142 is formed in the substrate 101 (FIG. 6 (A)). When the 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 the through holes 142 can be arbitrarily determined according to the design of the passive element 140. After that, the seed layers 102a and 144a are formed so as to cover at least a part of the side wall of the through hole 142 and a part of both surfaces (first surface, second surface) of the substrate 101. The seed layers 102a and 144a can be formed by a sputtering method, a CVD method, electroless plating, a vapor deposition method, or the like. In particular, by applying the sputtering method, the seed layers 102a and 144a are efficiently formed. Although not shown, before the formation of the seed layers 102a and 144a, an insulating film containing an organic compound such as polyimide or polyamide or an inorganic compound such as silicon oxide or silicon nitride is further formed on both sides of the side wall of the through hole 142 and the substrate 101. , Or a plurality of layers may be formed.

Next, a resist mask 150 for protecting the region where the first wiring 102 and the through electrode 144 are not formed is formed on the first surface and the second surface of the substrate 101 (FIG. 6A). The resist mask 150 may be formed by applying and curing a liquid resist, but since the substrate 101 has 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 exposing and developing.

After that, the seed layers 102a and 144a are fed to perform electrolytic plating to form a metal film on the seed layers 102a and 144a not covered with the resist mask 150, and the second layer 102b of the first wiring 102 and the second layer 102b 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 to form the first wiring 102 and the through electrode 144. (FIG. 6 (C)). As the 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.

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

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

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

Subsequently, the second insulating film 122 is formed so as to cover a part of the first wiring 102, the first insulating film 104, and the second wiring 106 (FIG. 7 (C)). Specifically, a photosensitive polymer such as polyimide described in the first embodiment or a solution or suspension thereof is applied onto the substrate 101, and then exposure, development, and firing using a photomask are performed. This forms a second insulating film 122 having an opening that exposes the second wiring 106. Alternatively, the second insulating film 122 may be formed by attaching the polymer film and performing exposure, development, and firing using a photomask. The thickness of the second insulating film 122 is appropriately adjusted in the range of 0.5 μm to 5 μm.

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

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

In this embodiment, the result of performing a reliability test on the passive element of the first embodiment will be described. The passive element used was a passive element 140 (see FIG. 5), and the seed layer 102a was formed by an electroless plating method so as to have a thickness of 0.1 μm. 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 a sputtering method. Similarly, a barrier layer containing titanium (thickness 0.1 μm) and a seed layer 124a containing copper (thickness 0.2 μm) were formed on the second wiring 106. 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 the plasma CVD method, and their thicknesses are 0.2 μm, 1.0 μm, and 0, respectively. It was .4 μm.

The prepared passive element was allowed to stand for 96 hours under the conditions of a temperature of 130 ° C. and a humidity of 85%, and then the cross section was 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 capacitance element 108 formed by the first wiring 102, the first insulating film 104, and the second wiring 106, it was confirmed that a capacitance value substantially the same as the design value can be obtained.

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

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

Each of the above-described embodiments as the embodiments of the present disclosure can be appropriately combined and implemented as long as they do not contradict each other. In addition, those skilled in the art who have appropriately added, deleted, or changed the design of components based on each embodiment are also included in the scope of the present disclosure as long as the gist of the present disclosure is provided.

In addition, even if the effects are different from the effects brought about by each of the above-described embodiments, those that are clear from the description of the present specification or those that can be easily predicted by those skilled in the art are of course. It is understood to be brought about by this 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 insulating Film, 124: 3rd wiring, 124a: seed layer, 124b: 2nd layer, 126: 3rd 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 (29)

substrate,
The first wiring on the board,
The second wiring on the first wiring,
A first insulating film located between the first wiring and the second wiring and in contact with the first wiring and the second wiring .
A protective film on the second wiring , and
It is located between the second wiring and the protective film, and has a third wiring that is in contact with the second wiring and the protective film .
The protective film is
A first inorganic film containing silicon nitride,
A second inorganic film located on the first inorganic film, in contact with the first inorganic film, and containing silicon oxide, and on the second inorganic film, the second inorganic film. A passive element that is in contact with and contains a third inorganic film containing silicon nitride. The passive element according to claim 1, wherein the thickness of the third inorganic film is larger than the thickness of the first inorganic film and smaller than the thickness of the second inorganic film. The first wiring and the second wiring are each
Located on a first layer containing a metal selected from titanium, chromium, nickel, copper, and gold, as well as on the first layer, titanium, aluminum, copper, nickel, tungsten, molybdenum, gold, silver, iron. , And the passive element of claim 1, comprising a second layer comprising a metal selected from chromium. The first wire and at least one of the second wires are located below the first layer and are in contact with the first layer to contain a metal selected from titanium, tantalum, molybdenum, and tungsten. Further has a third layer containing,
The passive element according to claim 3, wherein the metal contained in the third layer has a melting point higher than that of the metal contained in the second layer. The passive element according to claim 1, which is located between the second wiring and the protective film, covers a part of the second wiring, and further has a second insulating film containing an organic compound. The passive element according to claim 5, wherein the dielectric loss tangent of the organic compound is 1 × 10 ^-4 or more and 1 × 10 ⁻² or less. The passive element according to claim 1 , further comprising a second insulating film containing an organic compound, covering a part of the second wiring, partially covering the third wiring, and in contact with the protective film. .. The passive element according to claim 7 , wherein the organic compound has a dielectric loss tangent of 1 × 10 ^-4 or more and 1 × 10 ⁻² or less. The protective film has an opening that overlaps with the second wiring.
The passive element according to claim 1, further comprising a third wire that is located on the protective film, is in contact with the protective film, and is in contact with the second wire at the opening. The passive element according to claim 9 , further comprising a third insulating film located on the third wiring and the protective film and containing an organic compound. The passive element according to claim 1, wherein the first insulating film is in contact with a side surface of the first wiring. The passive element according to claim 1, wherein the first insulating film is in contact with the upper surface of the substrate. The passive element according to claim 1, wherein the first insulating film contains silicon nitride. The passive element according to claim 1, wherein the passive element is a high frequency device. A substrate having a first surface and a second surface facing each other and having through holes,
A first wiring that overlaps the first surface, the second surface, and the side wall of the through hole.
A second wire located on the first surface via 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 .
The protective film on the second wiring , as well as
It is located between the second wiring and the protective film, and has a third wiring that is in contact with the second wiring and the protective film .
The protective film is
A first inorganic film containing silicon nitride,
A second inorganic film located on the first inorganic film, in contact with the first inorganic film, and containing silicon oxide, and on the second inorganic film, the second inorganic film. A passive element that is in contact with and contains a third inorganic film containing silicon nitride. The passive element according to claim 15 , wherein the thickness of the third inorganic film is larger than the thickness of the first inorganic film and smaller than the thickness of the second inorganic film. The first wiring and the second wiring are each
Located on a first layer containing a metal selected from titanium, chromium, nickel, copper, and gold, as well as on the first layer, titanium, aluminum, copper, nickel, tungsten, molybdenum, gold, silver, iron. , And the passive element of claim 15 , comprising a second layer comprising a metal selected from chromium. The first wire and at least one of the second wires are located below the first layer and are in contact with the first layer to contain a metal selected from titanium, tantalum, molybdenum, and tungsten. Further has a third layer containing,
The passive element according to claim 17 , wherein the metal contained in the third layer has a melting point higher than that of the metal contained in the second layer. The passive element according to claim 15 , which is located between the second wiring and the protective film, covers a part of the second wiring, and further has a second insulating film containing an organic compound. The passive element according to claim 19 , wherein the organic compound has a dielectric loss tangent of 1 × 10 ^-4 or more and 1 × 10 ⁻² or less. 15. Claim 15 is located between the second wiring and the third wiring, contains an organic compound, covers a part of the second wiring, and further has a second insulating film in contact with the protective film. The passive element according to. The passive element according to claim 21 , wherein the organic compound has a dielectric loss tangent of 1 × 10 ^-4 or more and 1 × 10 ⁻² or less. The protective film has an opening that overlaps with the second wiring.
15. The passive element of claim 15 , further comprising a third wire that is located above the protective film, is in contact with the protective film, and is in contact with the second wire at the opening. 23. The passive element according to claim 23 , which is located on the third wiring and the protective film and further has a third insulating film containing an organic compound. It has a filler in the through hole and has
The passive element according to claim 15 , wherein the filler contains a metal or a resin. The passive element according to claim 15 , wherein the first insulating film is in contact with a side surface of the first wiring. The passive element according to claim 15 , wherein the first insulating film is in contact with the upper surface of the substrate. The passive element according to claim 15 , wherein the first insulating film contains silicon nitride. The passive element according to claim 15 , wherein the passive element is a high frequency device.

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