Through-electrode substrate

Abstract

To provide a through-electrode substrate with high reliability. [Solution] The present disclosure provides a through-electrode substrate 1 comprising a glass substrate 2 having a first surface 2a and a second surface 2b facing the first surface 2a and having a through hole 2h, a through electrode 3 disposed in the through hole 2h, a first wiring layer 4 disposed on the first surface 2a of the glass substrate 2, and a second wiring layer 5 disposed on the second surface 2b of the glass substrate 2, wherein the through electrode 3 is in contact with a part of the first wiring layer 4 and a part of the second wiring layer 5, the first wiring layer 4 and the second wiring layer 5 each having a lower barrier film 3a, a conductive film 3b and an upper barrier film in order from the glass substrate 2 side, the through electrode 3 having a lower barrier film 4a and a conductive film 4b in order from the side wall side of the through hole 2h, and the upper barrier film and the lower barrier film each containing a metal, alloy or metal oxide.

Description

Technical Field

[0001] The present disclosure relates to a through-electrode substrate.

Background Art

[0002] With the increasing sophistication and high performance of various electronic devices, higher reliability has been increasingly required for wiring boards. Furthermore, as the wiring boards are becoming more densely packed and the wiring pitch is getting finer, ensuring high reliability has become important.

[0003] For example, as a method of forming copper wiring, a damascene process is known in which grooves are formed in an insulating layer and copper wiring is embedded in the grooves. In the damascene process, a barrier metal layer is formed on the bottom and side surfaces of the copper wiring and a cap layer is formed on the top surface of the copper wiring to suppress electromigration. Patent Document 1 discloses a method for manufacturing an organic interposer in which a plurality of groove portions are formed in a first organic insulating film, a first barrier metal film is formed so as to cover the inner surfaces of the groove portions, a wiring layer is formed so as to fill the groove portions, a second barrier metal film is formed so as to cover the wiring layer in the groove portions, and a second organic insulating film is formed on the first organic insulating film and the second barrier metal film. In Patent Document 1, it is said that the barrier metal film suppresses the diffusion of the metal material in the wiring layer into the organic insulating film.

[0004] Also, Patent Document 2 discloses a method for manufacturing a multilayer wiring board in which a power supply layer is formed on a substrate, a resist layer is formed on the power supply layer, grooves are formed in the resist layer, a copper conductor layer is filled in the grooves, a protective layer is formed on the surface of the conductor layer after exposing the surface of the conductor layer, the resist layer is removed, an insulating layer is formed so as to cover the conductor layer, and the insulating layer is polished to expose the protective layer on the surface of the conductor layer. In Patent Document 2, it is said that the protective layer improves the adhesion between the copper conductor layer and the insulating layer.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-178140 [Patent Document 2] Japanese Patent Application Publication No. 8-23166 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Known insulating substrates for wiring boards include, for example, glass epoxy substrates, resin substrates containing epoxy resin or acrylic resin, and glass substrates. Among these, glass substrates are particularly favored due to their excellent optical properties such as flatness, dimensional stability, heat resistance, insulation, and transparency, and development of wiring boards using glass substrates is progressing.

[0007] In recent years, components comprising an insulating substrate with multiple through-holes and through-electrodes provided inside the through-holes, known as through-electrode substrates, have been used in a variety of applications. For the reasons mentioned above, glass substrates are sometimes used as the insulating substrate constituting the through-electrode substrate. Such glass substrates with through-holes are called TGV (Through-Glass Via).

[0008] As mentioned above, high reliability is required for printed circuit boards. In particular, because glass substrates have high heat resistance, the manufacturing process of printed circuit boards may include high-temperature heat treatments such as solder reflow processes, requiring a high level of reliability.

[0009] This disclosure is an invention made in view of the above circumstances, and its main objective is to provide a highly reliable through-electrode substrate. [Means for solving the problem]

[0010] One embodiment of the present disclosure provides a through-electrode substrate having a glass substrate having a first surface and a second surface opposite to the first surface and having a through hole, a through electrode disposed in the through hole, a first wiring layer disposed on the first surface of the glass substrate, and a second wiring layer disposed on the second surface of the glass substrate, wherein the through electrode is in contact with a part of the first wiring layer and a part of the second wiring layer, the first wiring layer and the second wiring layer each have a lower barrier film, a conductive film and an upper barrier film in that order from the glass substrate side, the through electrode has a lower barrier film and a conductive film in that order from the side wall side of the through hole, and the upper barrier film and the lower barrier film each contain a metal, alloy or metal oxide. [Effects of the Invention]

[0011] This disclosure offers the advantage of providing a highly reliable through-electrode substrate. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic cross-sectional view illustrating a through-electrode substrate in this disclosure. [Figure 2] This is a schematic cross-sectional view illustrating a through-electrode substrate in this disclosure. [Figure 3] This is a schematic cross-sectional view illustrating a glass substrate that constitutes a through-electrode substrate in this disclosure. [Figure 4] This is a schematic cross-sectional view illustrating a through-electrode substrate in this disclosure. [Figure 5] This is a schematic cross-sectional view illustrating a through-electrode substrate in this disclosure. [Modes for carrying out the invention]

[0013] Embodiments of this disclosure will be described below with reference to drawings and other figures. However, this disclosure can be implemented in many different ways and should not be interpreted as being limited to the embodiments described below. In addition, the drawings may be schematically represented in terms of width, thickness, shape, etc. of each part compared to the actual form in order to make the explanation clearer, but these are merely examples and should not limit the interpretation of this disclosure. Furthermore, in this specification and each figure, elements similar to those described above with respect to previously shown figures will be denoted by the same reference numerals, and detailed explanations may be omitted as appropriate.

[0014] In this specification, when describing a configuration in which one member is placed on top of another member, unless otherwise specified, the terms "on top" or "below" include both cases: one in which the other member is placed directly above or below the other member so as to be in contact with it, and another in which the other member is placed above or below the other member via yet another member. Similarly, when describing a configuration in this specification in which one member is placed on the surface of another member, unless otherwise specified, the terms "on the surface" or "on the surface" include both cases: one in which the other member is placed directly above or below the other member so as to be in contact with it, and another in which the other member is placed above or below the other member via yet another member.

[0015] The through-electrode substrate in this disclosure will be described in detail below.

[0016] The through-electrode substrate in this disclosure comprises a glass substrate having a first surface and a second surface opposite to the first surface and having a through hole, a through-electrode disposed in the through hole, a first wiring layer disposed on the first surface of the glass substrate, and a second wiring layer disposed on the second surface of the glass substrate, wherein the through-electrode is in contact with a part of the first wiring layer and a part of the second wiring layer, the first wiring layer and the second wiring layer each have a lower barrier film, a conductive film and an upper barrier film in that order from the glass substrate side, the through-electrode has a lower barrier film and a conductive film in that order from the side wall side of the through hole, and the upper barrier film and the lower barrier film each contain a metal, an alloy or a metal oxide.

[0017] FIG. 1 is a schematic cross-sectional view showing an example of a through-electrode substrate in the present disclosure. As shown in FIG. 1, the through-electrode substrate 1A has a first surface 2a and a second surface 2b facing the first surface 2a, and includes a glass substrate 2 having through-holes 2h, through-electrodes 3 disposed in the through-holes 2h, a first wiring layer 4 disposed on the first surface 2a side of the glass substrate 2, a second wiring layer 5 disposed on the second surface 2b side of the glass substrate 2, a first insulating layer 11 disposed on the surface of the first wiring layer 4 opposite to the glass substrate 2, and a second insulating layer 21 disposed on the surface of the second wiring layer 5 opposite to the glass substrate 2. The through-electrode 3 is in contact with a part of the first wiring layer 4 and a part of the second wiring layer 5. The first wiring layer 4 includes a lower barrier film 4a, a conductive film 4b, and an upper barrier film 4c in this order from the glass substrate 2 side, and the second wiring layer 5 includes a lower barrier film 5a, a conductive film 5b, and an upper barrier film 5c in this order from the glass substrate 2 side. The through-electrode 3 includes a lower barrier film 3a and a conductive film 3b in this order from the side wall side of the through-hole 2h. The upper barrier films 4c and 5c and the lower barrier films 3a, 4a, and 5a each contain a metal, an alloy, or a metal oxide. Further, the through-electrode 3 is a conformal via, and the inside of the through-hole 2h is filled with a resin portion 3d.

[0018] As described above, since the glass substrate has high heat resistance, high-temperature heat treatments such as a solder reflow process and a curing process of an insulating layer may be included in the manufacturing process of the wiring substrate, and high reliability is required.

[0019] For example, high-temperature heat treatment can reduce the adhesion between the wiring layer and the glass substrate, or between the wiring layer and the insulating layer. Specifically, the thermal expansion coefficients of the metal constituting the wiring layer and the glass constituting the glass substrate are significantly different. Also, the thermal expansion coefficients of the metal constituting the wiring layer and the resin constituting the insulating layer are significantly different. Therefore, after heating and cooling during heat treatment, the difference in thermal expansion coefficients causes stress at the interface between the wiring layer and the glass substrate, reducing the adhesion between the wiring layer and the glass substrate. Similarly, after heating and cooling during heat treatment, the difference in thermal expansion coefficients causes stress at the interface between the wiring layer and the insulating layer, potentially reducing the adhesion between the wiring layer and the insulating layer. Furthermore, similar to the wiring layer, high-temperature heat treatment can reduce the adhesion between the through-electrode and the glass substrate. In particular, if the through-electrode is a conformal via, the adhesion is more likely to decrease because the thickness of the conductive film constituting the through-electrode is thin.

[0020] Furthermore, stress migration can occur due to high-temperature heat treatment, for example. Specifically, after heating and cooling during heat treatment, stress is applied to the wiring layer due to the difference in thermal expansion coefficients mentioned above. This stress causes metal atoms in the wiring layer to move, creating voids within the wiring layer. As a result, voids are formed in the wiring layer, causing the wiring layer to break.

[0021] In contrast, in this disclosure, the first wiring layer 4 has a lower barrier film 4a and an upper barrier film 4c on both sides, the second wiring layer 5 has a lower barrier film 5a and an upper barrier film 5c on both sides, and the through electrode 3 has a lower barrier film 3a on the side wall side of the through hole 2h. The lower barrier films 3a, 4a, and 5a improve the adhesion between the through electrode 3 and the glass substrate 2, the adhesion between the first wiring layer 4 and the glass substrate 2, and the adhesion between the second wiring layer 5 and the glass substrate 2. Furthermore, the upper barrier films 4c and 5c improve the adhesion between the first wiring layer 4 and the first insulating layer 11, and the adhesion between the second wiring layer 5 and the second insulating layer 21. Therefore, even if the manufacturing process of the through electrode substrate includes high-temperature heat treatment, a decrease in the adhesion between the wiring layer and the glass substrate, the adhesion between the wiring layer and the insulating layer, and the adhesion between the through electrode and the glass substrate can be suppressed.

[0022] In addition, in the present disclosure, the lower barrier films 3a, 4a, and 5a can suppress the diffusion of metal atoms in the through electrode 3 into the glass substrate 2, the diffusion of metal atoms in the first wiring layer 4 into the glass substrate 2, and the diffusion of metal atoms in the second wiring layer 5 into the glass substrate 2. Therefore, even when the manufacturing process of the through electrode substrate includes high-temperature heat treatment, the occurrence of stress migration can be suppressed. Also, when an electric current is passed through the wiring layer, the generation of electromigration, in which electrons collide with metal atoms and the metal atoms move, can be suppressed. Furthermore, particularly under high humidity, when an electric current is passed through the wiring layer, the generation of electrochemical migration, in which metal is ionized and metal ions move, can be suppressed. In electromigration and electrochemical migration, the moved metal may cause obstacles such as short circuits between wiring layers, but such obstacles can be suppressed by the lower barrier film.

[0023] Therefore, in the present disclosure, the reliability can be improved.

[0024] Also, in the present disclosure, by appropriately selecting the materials of the upper barrier films 4c and 4d, the electrical resistance of the upper barrier films 4c and 5c can be lowered. That is, the electrical resistance of the surface of the first wiring layer 4 opposite to the glass substrate 2 and the electrical resistance of the surface of the second wiring layer 5 opposite to the glass substrate 2 can be lowered. Thereby, the high-frequency transmission characteristics can be improved.

[0025] Hereinafter, the through electrode substrate in the present disclosure will be described for each component.

[0026] 1. First Wiring Layer The first wiring layer in the present disclosure is disposed on the first surface of the glass substrate, and includes a lower barrier film, a conductive film, and an upper barrier film in this order from the glass substrate side. The first wiring layer is preferably in direct contact with the glass substrate.

[0027] (1) Upper Barrier Film The upper barrier film constituting the first wiring layer contains a metal, alloy, or metal oxide. The material of the upper barrier film preferably has good adhesion to the first insulating layer and can suppress the diffusion of metal atoms in the conductive film into the first insulating layer. Specifically, examples of materials for the upper barrier film include titanium, nickel, palladium, chromium, tantalum, tungsten, gold, copper, molybdenum, aluminum, cobalt, ruthenium, iridium, their alloys, and their oxides. Among these, the upper barrier film preferably contains a copper alloy. Because copper alloys have high conductivity, they can improve the conductivity of the upper barrier film and thus improve high-frequency transmission characteristics.

[0028] Copper alloys primarily consist of copper. The copper content in the copper alloy is preferably 80 atomic% or more, more preferably 90 atomic% or more, and even more preferably 95 atomic% or more. If the copper content is within the above range, the conductivity of the upper barrier film can be increased, improving high-frequency transmission characteristics. On the other hand, the upper limit of the copper content in the copper alloy is not particularly limited, for example, 99 atomic% or less. When the upper barrier film contains a copper alloy, the copper content in the copper alloy is a value obtained from compositional analysis by X-ray photoelectron spectroscopy (XPS).

[0029] The elements other than copper that make up the copper alloy are not particularly limited as long as a conductive copper alloy can be obtained, and examples include chromium, tin, nickel, zinc, titanium, silicon, magnesium, beryllium, cobalt, iron, manganese, and lead. Among these, the copper alloy is preferably made of chromium because it has an excellent balance of conductivity and barrier properties.

[0030] In the first wiring layer, the upper barrier film is positioned on the side of the conductive film opposite to the glass substrate. As shown in Figure 2, the upper barrier film 4c may also be positioned on the side of the conductive film 4b.

[0031] The thickness of the upper barrier film is preferably such that it adheres well to the first insulating layer and suppresses the diffusion of metal atoms in the conductive film into the first insulating layer. The thickness of the upper barrier film is preferably, for example, 5 nm or more, more preferably 8 nm or more, and even more preferably 10 nm or more. If the thickness of the upper barrier film is within the above range, adhesion to the first insulating layer can be improved, the diffusion of metal atoms in the conductive film into the first insulating layer can be further suppressed, and disconnection due to stress can be mitigated. On the other hand, the thickness of the upper barrier film is preferably, for example, 400 nm or less, more preferably 300 nm or less, and even more preferably 200 nm or less. If the thickness of the upper barrier film is within the above range, it is easier to ensure the conductivity of the entire first wiring layer. Specifically, the thickness of the upper barrier film is preferably 5 nm or more and 400 nm or less, more preferably 8 nm or more and 300 nm or less, and even more preferably 10 nm or more and 200 nm or less.

[0032] In this specification, the thickness of each layer is measured based on cross-sectional images of the through-electrode substrate taken using a scanning electron microscope (SEM). The thickness is the arithmetic mean of the thicknesses at any five locations.

[0033] Methods for forming the upper barrier film include, for example, PVD methods such as vacuum deposition and sputtering, and CVD methods.

[0034] (2) Lower barrier membrane The lower barrier film constituting the first wiring layer contains a metal, alloy, or metal oxide. The material of the lower barrier film preferably has good adhesion to the glass substrate and can suppress the diffusion of metal atoms in the conductive film into the glass substrate. Specifically, examples of materials for the lower barrier film include titanium, nickel, palladium, chromium, tantalum, tungsten, gold, copper, molybdenum, aluminum, their alloys, and their oxides. Among these, the lower barrier film preferably contains titanium, a titanium alloy, or a titanium oxide. This can improve adhesion to the glass substrate.

[0035] The thickness of the lower barrier film is preferably such that it adheres well to the glass substrate and suppresses the diffusion of metal atoms in the conductive film into the glass substrate. For example, the thickness of the lower barrier film is preferably 5 nm or more, more preferably 8 nm or more, and even more preferably 10 nm or more. If the thickness of the lower barrier film is within the above range, adhesion to the glass substrate can be improved, the diffusion of metal atoms in the conductive film into the glass substrate can be further suppressed, and disconnection due to stress can be mitigated. On the other hand, for example, the thickness of the lower barrier film is preferably 100 nm or less, more preferably 60 nm or less, and even more preferably 40 nm or less. If the thickness of the lower barrier film is within the above range, it is easier to ensure the conductivity of the entire first wiring layer. Specifically, the thickness of the lower barrier film is preferably 5 nm or more and 100 nm or less, more preferably 8 nm or more and 60 nm or less, and even more preferably 10 nm or more and 40 nm or less.

[0036] Methods for forming the upper barrier film include, for example, PVD methods such as vacuum deposition and sputtering, and CVD methods.

[0037] (3) Conductive film The material of the conductive film constituting the first wiring layer is not particularly limited as long as it is a conductive material, and examples include metals such as copper, gold, silver, platinum, rhodium, tin, aluminum, nickel, and chromium, or alloys containing these metals. Among these, the conductive film preferably contains copper, aluminum, and silver, and more preferably contains copper. These metals have high conductivity, are relatively inexpensive, and are readily available. Furthermore, these metals tend to undergo migration.

[0038] The conductive film may be a single layer or a multilayer with multiple layers stacked on top of each other. For example, the conductive film may have a seed layer and a plating layer in that order from the lower barrier film side. The material for the seed layer can be appropriately selected from materials used for seed layers in general plating methods. Examples of materials for the seed layer include the conductive film material. As for the plating layer material, a conductive material that adheres well to the seed layer is preferred, and examples of materials for the conductive film include the conductive film material.

[0039] The thickness of the conductive film is, for example, 0.5 μm to 30 μm, but may also be 1 μm to 20 μm, or 3 μm to 10 μm. If the thickness of the conductive film is within the above range, the conductivity of the entire first wiring layer can be ensured, and disconnection due to stress can be mitigated.

[0040] Methods for forming conductive films include, for example, PVD methods such as vacuum deposition and sputtering, CVD methods, and plating methods.

[0041] 2.Second wiring layer The second wiring layer in this disclosure is arranged on the second surface of the glass substrate and has, in order from the glass substrate side, a lower barrier film, a conductive film, and an upper barrier film. The second wiring layer is preferably in direct contact with the glass substrate.

[0042] The lower barrier film, conductive film, and upper barrier film constituting the second wiring layer are the same as those constituting the first wiring layer described above, so their explanation is omitted here.

[0043] The lower barrier film constituting the first wiring layer and the lower barrier film constituting the second wiring layer may be the same or different from each other. Similarly, the upper barrier film constituting the first wiring layer and the upper barrier film constituting the second wiring layer may be the same or different from each other. Furthermore, the conductive film constituting the first wiring layer and the conductive film constituting the second wiring layer may be the same or different from each other.

[0044] 3.Through electrode The through-electrode in this disclosure is positioned within a through-hole in a glass substrate and has a lower barrier film and a conductive film in that order from the side wall side of the through-hole. The through-electrode is also in contact with a portion of the first wiring layer and a portion of the second wiring layer.

[0045] The through-electrode only needs to be able to electrically connect the first and second surfaces of the glass substrate, and its form is not particularly limited. The form of the through-electrode may be, for example, a through-electrode that fills a through-hole, a so-called filled via, or a through-electrode placed only on the side wall of a through-hole, a so-called conformal via. Furthermore, if the through-electrode is a conformal via, a hollow portion may be placed inside the through-hole, or the inside of the through-hole may be filled with a resin portion. Figure 1 is an example of a conformal via, and Figure 3 is an example of a filled via.

[0046] In particular, the through-electrode is preferably a conformal via. Compared to a filled via, the process of forming the through-electrode can be shortened. In addition, it is possible to avoid the reduction in long-term reliability caused by voids in the filled via that tend to occur during the formation process of a filled via. Furthermore, in the case of conformal vias, if the through-electrode peels off from the side wall of the through-hole, poor conductivity will occur, so the adhesion between the through-hole in the glass substrate and the through-electrode is important. In particular, since the thickness of the glass substrate is greater than the thickness of the interlayer insulating layer that makes up the wiring board, the adhesion of the through-electrode becomes even more important. Especially with through-electrodes with a high aspect ratio, it is difficult to ensure sufficient adhesion of the through-electrode. For this reason, this disclosure is useful in the case of conformal vias.

[0047] (1) Conductive film The conductive film constituting the through-electrode is the same as the conductive film constituting the first wiring layer described above, so its explanation is omitted here.

[0048] Since the through-electrode is in contact with a portion of the first wiring layer and a portion of the second wiring layer, it is preferable that the conductive film constituting the through-electrode is the same as the conductive film constituting the first wiring layer or the conductive film constituting the second wiring layer.

[0049] As shown in Figure 1, when the through-electrode is a conformal via, the thickness of the conductive film is, for example, 0.5 μm to 30 μm, may be 1 μm to 20 μm, or 3 μm to 10 μm. If the thickness of the conductive film is within the above range, the conductivity of the entire through-electrode can be ensured, and disconnection due to stress can be mitigated.

[0050] (2) Lower barrier membrane The lower barrier film constituting the through-electrode contains a metal, alloy, or metal oxide. Since the lower barrier film constituting the through-electrode is the same as the lower barrier film constituting the first wiring layer described above, a detailed explanation is omitted here.

[0051] Since the through-electrode is in contact with a portion of the first wiring layer and a portion of the second wiring layer, it is preferable that the lower barrier film constituting the through-electrode is the same as the lower barrier film constituting the first wiring layer or the lower barrier film constituting the second wiring layer.

[0052] (3) Upper barrier membrane When the through electrode is a conformal via, as shown in Figure 2, the through electrode 3 may have a lower barrier film 3a, a conductive film 3b, and an upper barrier film 3c in that order from the side wall side of the through hole 2h. The upper barrier film constituting the through electrode contains a metal, alloy, or metal oxide. The upper barrier film constituting the through electrode is the same as the upper barrier film constituting the first wiring layer described above, so its explanation is omitted here.

[0053] Since the through-electrode is in contact with a portion of the first wiring layer and a portion of the second wiring layer, it is preferable that the upper barrier film constituting the through-electrode is the same as the upper barrier film constituting the first wiring layer or the upper barrier film constituting the second wiring layer.

[0054] (4) Resin part When the through-electrode is a conformal via and the through-hole is filled with a resin portion, examples of materials for the resin portion include epoxy resin, acrylic resin, polyimide, polyamide, and polyester.

[0055] 4. Glass substrate The glass substrate in this disclosure has a first surface and a second surface opposite to the first surface, and has through holes that penetrate the glass substrate in the thickness direction.

[0056] Because glass substrates have good flatness, fine wiring can be formed at a narrow pitch. Furthermore, since the thermal expansion coefficient of the glass substrate can be adjusted by its composition, a glass substrate with a desirable thermal expansion coefficient can be selected.

[0057] Examples of glass used in glass substrates include alkali-free glass and quartz.

[0058] The planar shape of the glass substrate is not particularly limited and can include, for example, rectangles or squares.

[0059] The plan view shape of the through-hole in the glass substrate is, for example, approximately circular. The cross-sectional shape of the through-hole 2h in the glass substrate 2 can be, for example, a straight shape as shown in Figure 1, an inverse tapered shape as shown in Figure 4(a) where the opening diameter on the first surface 2a side is larger than the opening diameter on the second surface 2b side, a forward tapered shape as shown in Figure 4(b) where the opening diameter on the first surface 2a side is smaller than the opening diameter on the second surface 2b side, an hourglass shape as shown in Figure 4(c) which includes a portion where the diameter is smallest at a predetermined position between the first surface 2a and the second surface 2b, or a bowing shape as shown in Figure 4(d) where the diameter is largest at a predetermined position between the first surface 2a and the second surface 2b. Figures 4(a) to 4(d) are schematic cross-sectional views illustrating the cross-sectional shapes of the through-holes in the glass substrate.

[0060] The thickness of the glass substrate is, for example, 100 μm or more, but may also be 200 μm or more, 300 μm or more, or 400 μm or more. By having the glass substrate thickness within the above range, it is possible to suppress excessive deflection of the glass substrate. This prevents difficulties in handling the glass substrate during the manufacturing process, and prevents the glass substrate from warping due to internal stresses such as thin films placed on the first or second surface of the glass substrate. On the other hand, the thickness of the glass substrate is, for example, 2000 μm or less, but may also be 1000 μm or less, or 800 μm or less. If the thickness of the glass substrate is within the above range, the time required for the process of forming through holes in the glass substrate can be shortened. Specifically, the thickness of the glass substrate is 100 μm or more and 2000 μm or less, but may also be 200 μm or more and 1000 μm or less, 300 μm or more and 1000 μm or less, or 400 μm or more and 800 μm or less.

[0061] 5. First Wiring Stack The through-electrode substrate in this disclosure may have a first wiring laminate on the side of the glass substrate facing the first wiring layer, having one or more first insulating layers and one or more third wiring layers. In Figure 5, the through-electrode substrate 1 further comprises a first wiring laminate 10 on the side of the glass substrate 2 facing the first wiring layer 3, having a first insulating layer 11, a third wiring layer 12, and vias 13. The through-electrode 3 and the third wiring layer 12 are electrically connected via the vias 13.

[0062] (1) First insulating layer The material of the first insulating layer is preferably an insulating resin, and photosensitive resins and thermosetting resins commonly used for insulating layers can be used. If the first wiring laminate has multiple first insulating layers, the materials of the multiple first insulating layers may be the same or different.

[0063] The number of layers in the first insulating layer included in the first wiring laminate is one or more, may be two or more, three or more, or four or more. On the other hand, the number of layers m of the first insulating layer is preferably 10 or less, may be eight or less, or seven or less. Too many layers in the first insulating layer is disadvantageous in terms of cost.

[0064] The thickness of the first insulating layer is, for example, 1.5 μm or more, and may be 2.5 μm or more. On the other hand, the thickness of the first insulating layer is, for example, 30 μm or less. The thickness of the first insulating layer is, for example, 1.5 μm or more and 30 μm or less, and may be 2.5 μm or more and 30 μm or less. When the first wiring laminate has two or more first insulating layers, the thickness of the first insulating layer here is the sum of the thicknesses of each first insulating layer.

[0065] Methods for forming the first insulating layer include, for example, a method for forming a first insulating layer having openings by photolithography or screen printing, or a method for forming openings in the first insulating layer by laser processing.

[0066] (2) Third wiring layer The third wiring layer is preferably electrically connected to the through-electrode.

[0067] The third wiring layer has at least a conductive film. The third wiring layer may have only a conductive film, or it may have a lower barrier film, a conductive film, and an upper barrier film in that order from the glass substrate side. The conductive film and upper barrier film constituting the third wiring layer are the same as the conductive film and upper barrier film constituting the first wiring layer described above, so their explanation is omitted here. Also, the lower barrier film constituting the third wiring layer is the same as the upper barrier film constituting the first wiring layer described above, so their explanation is omitted here.

[0068] The number of third wiring layers included in the first wiring laminate may be one or two or more. When the first wiring laminate has two or more third wiring layers, each third wiring layer is laminated in the thickness direction via the first insulating layer. In addition, each third wiring layer is electrically connected via vias.

[0069] The method for forming the first wiring layer may be an additive method, a semi-additive method, or a subtractive method.

[0070] The vias connecting each third wiring layer may be so-called filled vias that fill the openings in the first insulating layer, or so-called conformal vias that are positioned only on the side walls of the openings in the first insulating layer.

[0071] The material used for the via is not particularly limited as long as it is a conductive material; any conductive material commonly used for vias can be used, and it can be appropriately selected depending on the via's shape, formation method, etc.

[0072] The method for forming vias can be a general via formation method, and the appropriate method can be selected depending on the via shape and other factors.

[0073] 6. Second Wiring Stack The through-electrode substrate in this disclosure may have a second wiring laminate on the side of the glass substrate facing the second wiring layer, having one or more second insulating layers and one or more fourth wiring layers. In Figure 5, the through-electrode substrate 1 further comprises a second wiring laminate 20 on the side of the glass substrate 2 facing the second wiring layer 3, having a second insulating layer 21, a fourth wiring layer 22, and vias 23. The through-electrode 3 and the fourth wiring layer 22 are electrically connected via the vias 23.

[0074] The second insulating layer, fourth wiring layer, and vias constituting the second wiring laminate are the same as the first insulating layer, third wiring layer, and vias constituting the first wiring laminate, respectively, so their explanation is omitted here.

[0075] The number of layers of the first insulating layer in the first wiring laminate and the number of layers of the second insulating layer in the second wiring laminate may be the same or different, but it is preferable that they be the same. When using a large glass substrate, warping of the glass substrate can be suppressed. Furthermore, it is preferable because the first insulating layer and the second insulating layer can be alternately laminated on the glass substrate during the manufacturing process of the through-electrode substrate.

[0076] 7.Applications The through-electrode substrate described herein can be used, for example, in semiconductor devices. Applications of semiconductor devices equipped with the through-electrode substrate are not limited to, but include, for example, notebook personal computers, tablet terminals, mobile phones, smartphones, digital video cameras, digital cameras, digital clocks, servers, car navigation systems, and home appliances.

[0077] This disclosure is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of this disclosure and achieves similar effects is included within the technical scope of this disclosure. [Examples]

[0078] [Example 1] A through-electrode substrate as shown in Figure 2 was fabricated. A glass substrate with a thickness of 400 μm and through-holes with a diameter of 130 μm was prepared. Ti sputtering and Cu sputtering were performed consecutively in the same batch on the first and second surfaces of the glass substrate and the inner walls of the through-holes to form a lower Ti barrier film and a Cu seed layer. A resist pattern was formed on the Cu seed layer using a dry film resist. The resist pattern was placed on the first surface 2a and the second surface 2b of the glass substrate 2 as shown in Figure 2. Next, Cu electroplating was performed to form a Cu plating layer on the exposed parts of the Cu seed layer. Furthermore, sputtering was performed using a Cu and Cr alloy target to form an upper barrier film of the Cu and Cr alloy. The resist pattern was peeled off and removed using a predetermined stripping solution. Next, the exposed Cu seed layer and the lower Ti barrier film were removed using an etching solution. This resulted in a wiring layer having a lower barrier film, a conductive film including the seed layer and plating layer, and an upper barrier film. Furthermore, a through-electrode, which is a conformal via, was obtained, having a lower barrier film, a conductive film including a seed layer and a plating layer, and an upper barrier film. Subsequently, the through-hole and the first and second surfaces of the glass substrate were covered with a dry film resist, and a resist pattern was applied to form an insulating layer.

[0079] [Example 2] A through-electrode substrate was fabricated in the same manner as in Example 1, except that in the upper barrier film formation process, a Cr target was used instead of a Cu and Cr alloy target, and a Cr upper barrier film was formed.

[0080] [Comparative Example 1] A through-electrode substrate was fabricated in the same manner as in Example 1, except that an upper barrier film was not formed.

[0081] [evaluation] (1) Adhesion In accordance with ISO 20502, the adhesion between the wiring layer and the insulating layer was evaluated by a scratch test. Specifically, a diamond indenter with a tip radius of 0.2 mm was pressed perpendicularly onto the insulating layer surface of the through-electrode substrate while simultaneously moving the substrate horizontally at 10 mm / min to scratch the insulating layer surface. Tests in which the insulating layer did not peel off were classified as "good," and those in which the insulating layer peeled off were classified as "poor."

[0082] (2) Migration The through-electrode substrate was heat-treated at 260°C and then returned to room temperature. The electrical resistance of the wiring layer was measured on the through-electrode substrate before and after heat treatment. Specifically, a two-terminal electrical resistance meter (HIOKI RM3545) was used, with one terminal in contact with an arbitrary position on the first wiring layer located on the first surface of the glass substrate, and the other terminal in contact with an arbitrary position on the second wiring layer located on the second surface of the glass substrate, to measure the electrical resistance. The measurement positions of the terminals were the same before and after heat treatment. An increase in the electrical resistance of the wiring layer after heat treatment compared to the electrical resistance of the wiring layer before heat treatment was defined as "good" if it was less than 10%, and "poor" if it was 10% or more. The wiring layers of the through-electrode substrates that were evaluated as "poor" were observed with a scanning electron microscope (SEM), and the presence of voids was confirmed.

[0083] (3) High-frequency transmission characteristics In forming the wiring layers on the through-electrode substrate described above, three parallel wiring layers with a length of 100 mm and a width of 10 μm were formed. The thickness of the resulting wiring layers was 5 μm. The spacing between the three wiring layers was 10 μm. Of the three wiring layers, the central wiring layer was designated as the signal line, and the wiring layers on either side were designated as the ground lines. The S12 characteristics of the wiring layers at both ends were evaluated using a vector network analyzer. In the range of 10 GHz to 20 GHz, those with relatively low loss were classified as "good," and those with relatively high loss were classified as "poor."

[0084] [Table 1]

[0085] As shown in Table 1, when the first and second wiring layers each have a lower barrier film, a conductive film, and an upper barrier film in that order from the glass substrate side, and the through-electrode has a lower barrier film and a conductive film in that order from the side wall side of the through-hole, it was confirmed that adhesion is good and migration is suppressed. Furthermore, it was shown that when the upper barrier film contains a copper alloy, high-frequency transmission characteristics are also good.

[0086] This disclosure provides the following inventions. [1] A glass substrate having a first surface and a second surface opposite the first surface, and having through holes, A through electrode placed inside the above-mentioned through hole, A first wiring layer is arranged on the first surface of the glass substrate described above, A second wiring layer arranged on the second surface of the glass substrate, A through-electrode substrate having, The through electrode is in contact with a part of the first wiring layer and a part of the second wiring layer. The first wiring layer and the second wiring layer each have, in order from the glass substrate side, a lower barrier film, a conductive film, and an upper barrier film. The through electrode has, in order from the side wall side of the through hole, a lower barrier film and a conductive film. A through-electrode substrate in which the upper barrier film and the lower barrier film each contain a metal, alloy, or metal oxide. [2] The through-electrode substrate according to [1], wherein the upper barrier film contains a copper alloy. [3] The above copper alloy contains chromium, as described in [2], for the through-electrode substrate. [4] The through-electrode substrate according to any one of [1] to [3], wherein the lower barrier film contains titanium, a titanium alloy, or a titanium oxide. [5] A through-electrode substrate according to any one of [1] to [4], wherein the through-electrode is a conformal via. [6] A first wiring laminate is disposed on the surface of the glass substrate facing the first wiring layer, and has one or more first insulating layers and one or more third wiring layers. A second wiring laminate is disposed on the side of the glass substrate facing the second wiring layer, and has one or more second insulating layers and one or more fourth wiring layers. A through-electrode substrate according to any one of [1] to [5], having the following characteristics. [Explanation of Symbols]

[0087] 1 ... Through-electrode substrate 2… Glass substrate 2a… First surface of the glass substrate 2b… ​​Second surface of the glass substrate 2h… Through hole 3 … Through electrode 4 … 1st wiring layer 5…Second wiring layer 3a, 4a, 5a… Lower barrier membrane 3b, 4b, 5b... Conductive film 3c, 4c, 5c… Upper barrier film 3d…Resin part 10… First wiring laminate 11… First insulating layer 12... 3rd wiring layer 20… Second wiring laminate 21… Second insulating layer 22... 4th wiring layer 13, 23... Beer

Claims

1. A glass substrate having a first surface and a second surface opposite the first surface, and having through holes, A through electrode placed inside the through hole, A first wiring layer disposed on the first surface of the glass substrate, A second wiring layer disposed on the second surface of the glass substrate, A through-electrode substrate having, The through electrode is in contact with a part of the first wiring layer and a part of the second wiring layer. The first wiring layer and the second wiring layer each have, in order from the glass substrate side, a lower barrier film, a conductive film, and an upper barrier film. The through electrode has, in order from the side wall side of the through hole, a lower barrier film and a conductive film, A through-electrode substrate in which the upper barrier film and the lower barrier film each contain a metal, alloy, or metal oxide.

2. The through-electrode substrate according to claim 1, wherein the upper barrier film contains a copper alloy.

3. The through-electrode substrate according to claim 2, wherein the copper alloy contains chromium.

4. The through-electrode substrate according to claim 1, wherein the lower barrier film comprises titanium, a titanium alloy, or a titanium oxide.

5. The through-electrode substrate according to claim 1, wherein the through-electrode is a conformal via.

6. A first wiring laminate is disposed on the surface of the glass substrate facing the first wiring layer, and has one or more first insulating layers and one or more third wiring layers, A second wiring laminate is disposed on the side of the glass substrate facing the second wiring layer, and has one or more second insulating layers and one or more fourth wiring layers. A through-electrode substrate according to claim 1, having the following characteristics.

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