Conductive film and wiring board

Abstract

A conductive film (1A) comprises: a sheet-shaped insulator (3) that has a groove portion (4) formed in the upper surface thereof; and wiring (10) that is positioned in the groove portion (4) along the groove portion (4). The wiring (10) has: a barrier layer (11) that is positioned inside the groove portion (4) and contains Ti; an adhesion layer (12) that is laminated on the barrier layer (11) and contains a NiCuTi alloy; and a conductive layer (13) that is laminated on the adhesion layer (12) and contains Cu. The adhesion layer (12) is positioned between the barrier layer (11) and the conductive layer (13). The adhesion layer (12) is in direct contact with the barrier layer (11) and the conductive layer (13).

Description

Conductive film and wiring board

[0001] This disclosure relates to conductive films and wiring substrates.

[0002] Conventionally, conductive films are known, for example, as shown in Patent Document 1.

[0003] Patent Document 1 discloses a wiring structure comprising an insulator (insulating film 11) with grooves (recesses 13) formed therein, a barrier metal layer (barrier metal layer 14) formed on the wall surface of the recess, and conductive layers (metal material bodies 15, 16) embedded inside the grooves. The barrier metal layer is made of titanium nitride (TiN). That is, the barrier metal layer contains titanium (Ti). The conductive layers (metal material bodies 15, 16) are made of copper (Cu). The barrier metal layer is located between the wall surface of the groove in the insulator and the conductive layer.

[0004] Japanese Patent Publication No. 2000-150647

[0005] Here, if a conductive layer is formed on the wall surface of the groove, then, for example, under high-temperature conditions of 150°C, the copper (Cu) contained in the conductive layer reacts with the acidic components of the insulator, making it easier for copper oxide to form between the conductive layer and the insulator. Cu produced by this oxidation ２＋ Ions have a higher diffusion coefficient compared to copper (Cu). Therefore, Cu produced by oxidation ２＋ Ions begin to diffuse into the insulator. Cu ２＋ When ions diffuse into an insulator, so-called voids are generated between the conductive layer and the walls of the grooves in the insulator, increasing the resistance of the wiring structure.

[0006] In contrast, the wiring structure of Patent Document 1 generally has a barrier metal layer containing Ti, which has high corrosion resistance, formed on the wall surface of the groove in the insulator. This suppresses the oxidation of Cu contained in the conductive layer, thus preventing the above-mentioned Cu ２＋ This prevents ions from diffusing into the insulator. As a result, the increase in resistance in the wiring structure is reduced.

[0007] However, because the interatomic bonds between titanium (Ti) and copper (Cu) are generally relatively weak, in the wiring structure of Patent Document 1, the adhesion between the barrier metal layer and the conductive layer at the interface was sometimes insufficient. In other words, in the wiring structure of Patent Document 1, since the barrier metal layer is located between the wall surface of the groove in the insulator and the conductive layer, there was a problem in that the bonding state between the groove in the insulator and the conductive layer was unstable.

[0008] Due to these problems, for example, in the manufacturing process of wiring structures (particularly the process of laminating a conductive layer containing Cu onto a barrier metal layer formed on the wall surface of a recess in an insulator), a portion of the interface between the barrier metal layer and the conductive layer may peel off, causing the conductive layer to fall out of the groove. Furthermore, due to insufficient adhesion between Ti and Cu, even when using a conductive film to which a wiring structure is applied, a portion of the interface between the barrier metal layer and the conductive layer may peel off, potentially causing the conductive layer to fall out of the groove.

[0009] This disclosure has been made in view of the above, and its purpose is to stabilize the bonding state between the groove portion of the insulator and the conductive layer.

[0010] To achieve the above objective, one embodiment of the present disclosure is a conductive film comprising a sheet-like insulator having grooves formed on its upper surface, and wiring positioned along the grooves. The wiring is located within the grooves and has a barrier layer containing Ti, an adhesion layer laminated on the barrier layer and containing a NiCuTi alloy, and a conductive layer laminated on the adhesion layer and containing Cu. The adhesion layer is located between the barrier layer and the conductive layer. The adhesion layer is in direct contact with the barrier layer and the conductive layer.

[0011] According to this disclosure, the bonding state between the groove portion of the insulator and the conductive layer can be stabilized.

[0012] Figure 1 is a schematic enlarged section showing the configuration of a conductive film according to the first embodiment of this disclosure. Figure 2 is a cross-sectional view taken along line II-II in Figure 1. Figure 3 is a partial enlarged view of part III shown in Figure 2. Figure 4 is a modified example of the conductive film according to the first embodiment, corresponding to Figure 3. Figure 5 is a schematic cross-sectional view showing the configuration of an interposer (wiring board) according to the second embodiment of this disclosure. Figure 6 is a modified example of the interposer (wiring board) according to the second embodiment, corresponding to Figure 5.

[0013] The embodiments of this disclosure will be described in detail below with reference to the drawings. The following descriptions of the embodiments are illustrative in nature and are not intended to limit this disclosure, its applications, or its uses.

[0014] [First Embodiment] Figure 1 shows a conductive film 1A according to an embodiment of the present disclosure. The conductive film 1A shown in Figure 1 can be widely applied to various technical fields such as touch sensors, liquid crystal displays, organic electroluminescent displays (OLEDs), micro-LED displays, solar cell devices, heater devices, antenna devices, and electromagnetic wave shielding sheets.

[0015] In the embodiments of this disclosure, for the sake of explanation, the direction from the left side of Figure 1 to the right side of the page (direction D1 shown in Figure 1) is defined as the "first direction." The direction from the bottom of Figure 1 to the top of the page (direction D2 shown in Figure 1) is defined as the "second direction."

[0016] Furthermore, in the following explanation, the side where the substrate 2 (described later) shown in Figure 2 is located (the lower side of the paper in Figure 2) will be referred to as the "lower side" of the conductive film 1A, and the side where the insulator 3 (described later) is located (the upper side of the paper in Figure 2) will be referred to as the "upper side" of the conductive film 1A, and the positional relationships of the elements constituting the conductive film 1A will be defined accordingly. Note that such positional relationships are unrelated to the actual vertical direction of the equipment or device on which the conductive film 1A is mounted.

[0017] As shown in Figures 1 and 2, the conductive film 1A comprises a base material 2, a sheet-like insulator 3, and a plurality of conductive wires 10. Each component will be described in detail below.

[0018] (Substrate) The substrate 2 is made of a transparent resin material. Examples of transparent resin materials include PET (polyethylene terephthalate), PC (polycarbonate), COP (cycloolefin polymer), and COC (cycloolefin copolymer). The thickness of the substrate 2 is, for example, 25 μm or more and 300 μm or less.

[0019] (Insulator) As shown in Figure 2, the insulator 3 is laminated on top of the base material 2. The insulator 3 is made of a resin material that has insulating and permeable properties. The thickness of the insulator 3 is greater than the depth of the groove 4, which will be described later.

[0020] Multiple grooves 4 are formed on the upper surface of the insulator 3. The grooves 4 have a bottomed shape that is recessed downwards towards the insulator 3.

[0021] In this embodiment, the side surface of the groove 4 is tapered, widening upward from the bottom surface of the groove 4 towards the opening side of the groove 4. Specifically, in the thickness direction of the insulator 3, the side surface of the groove 4 is inclined upward from the bottom surface of the groove 4 towards the opening side of the groove 4, either to the left or to the right of the paper in Figure 2. Note that the side surface of the groove 4 does not necessarily have to be tapered.

[0022] The groove width of groove 4 (dimension GW shown in Figure 2) is, for example, 0.5 μm or more and 20 μm or less. The depth of groove 4 (dimension GD shown in Figure 2) is, for example, 0.8 μm or more and 4.0 μm or less. The aspect ratio of groove 4 shown in Figure 2 (value obtained by dividing dimension GD by dimension GW) is, for example, 0.1 or more.

[0023] (Wiring) As shown in Figure 1, the conductive film 1A has a mesh pattern formed by a plurality of wires 10. The plurality of wires 10 extend in directions that intersect each of the first direction D1 and the second direction D2. Although not shown, the plurality of wires 10 may also extend along each of the first direction D1 and the second direction D2.

[0024] The line width of the wiring 10 is, for example, 0.5 μm or more and 20 μm or less. The spacing between adjacent wirings 10 is, for example, 1 μm or more and 600 μm or less.

[0025] The wiring 10 is made of a conductive material embedded in the groove 4 of the insulator 3. Specifically, as shown in Figure 2, the wiring 10 has a barrier layer 11, an adhesion layer 12, a conductive layer 13, and a covering layer 14. The specific configuration of each layer will be described in detail below. For the sake of clarity, the barrier layer 11, the conductive layer 13, and the covering layer 14 will be described first, followed by the adhesion layer 12.

[0026] (Barrier layer) As shown in Figure 2, the barrier layer 11 is located within the groove 4. The barrier layer 11 is in direct contact with the bottom and side surfaces of the groove 4. The barrier layer 11 is formed on the bottom and side surfaces of the groove 4, for example, by sputtering. The thickness of the barrier layer 11 is, for example, 0.005 μm or more and 0.1 μm or less (5 nm or more and 100 nm or less). The barrier layer 11 may be formed by methods other than sputtering.

[0027] The barrier layer 11 contains titanium (Ti). A specific example of the barrier layer 11 is titanium nitride (TiN) formed by sputtering. By positioning this barrier layer 11 between the insulator 3 (bottom and side surfaces of the groove 4) and the conductive layer 13, it prevents the oxidation of copper (Cu) contained in the conductive layer 13 in a high-temperature environment (e.g., 150°C), and also prevents the oxidation of Cu generated by oxidation. ２＋ This makes it possible to prevent ions from diffusing into the insulator 3. As a result, the increase in resistance in the wiring 10 can be reduced.

[0028] (Conductive layer) As shown in Figure 2, the conductive layer 13 is located within the groove 4. Specifically, the conductive layer 13 is laminated on the adhesion layer 12 and is in direct contact with the adhesion layer 12. This conductive layer 13 ensures the conductivity of the wiring 10.

[0029] The conductive layer 13 contains copper (Cu). The conductive layer 13 is formed, for example, by electroplating, electroless plating, or vacuum deposition. Although copper (Cu) is suitable as the main component of the conductive layer 13, other metal materials other than copper (for example, silver, gold, nickel, aluminum) may also be included as components.

[0030] (Coating layer) As shown in Figure 2, the coating layer 14 is laminated on the upper surface of the conductive layer 13. The coating layer 14 is in direct contact with the upper surface of the conductive layer 13.

[0031] The coating layer 14 contains nickel (Ni). The coating layer 14 is formed on the upper surface of the conductive layer 13 by, for example, electroplating, electroless plating, or vacuum deposition. The thickness of the coating layer 14 is, for example, 0.05 μm or more and 10 μm or less. By laminating this coating layer 14 on the upper surface of the conductive layer 13, the durability and corrosion resistance of the wiring 10 (especially the conductive layer 13) can be improved. Although nickel (Ni) is suitable as the main component of the coating layer 14, other metal materials other than nickel may be included as other components.

[0032] (Adhesion layer) The adhesion layer 12 is formed, for example, by sputtering. The thickness of the adhesion layer 12 is, for example, 5 μm or more and 100 μm or less. The adhesion layer 12 may also be formed by methods other than sputtering.

[0033] As shown in Figure 2, a characteristic configuration according to the first embodiment is that the adhesion layer 12 is laminated on the barrier layer 11. Specifically, the adhesion layer 12 is located between the barrier layer 11 and the conductive layer 13. The adhesion layer 12 is in direct contact with both the barrier layer 11 and the conductive layer 13.

[0034] The adhesion layer 12 contains a NiCuTi alloy. This NiCuTi alloy is, for example, a metallic material that constitutes a target installed inside a sputtering apparatus (not shown). The adhesion layer 12 may also contain small amounts of impurities (i.e., components other than the NiCuTi alloy) that are generated during the formation process of the adhesion layer 12 by sputtering.

[0035] Here, the titanium (Ti) contained in the barrier layer 11 and the nickel (Ni) contained in the NiCuTi alloy in the adhesion layer 12 are both first transition elements, and good chemical interactions are observed between them. Furthermore, since the thermal expansion coefficients of titanium (Ti) and nickel (Ni) are relatively similar, stress due to temperature changes is reduced at the interface between the barrier layer 11 and the adhesion layer 12. As a result, the adhesion between the barrier layer 11 and the adhesion layer 12 is maintained, and the adhesion layer 12 does not peel off from the barrier layer 11.

[0036] Furthermore, both nickel (Ni) contained in the NiCuTi alloy in the adhesion layer 12 and copper (Cu) contained in the conductive layer 13 are first transition elements, and good chemical interaction is observed between them. In addition, since the thermal expansion coefficients of nickel (Ni) and copper (Cu) are relatively similar, stress due to temperature changes is reduced at the interface between the adhesion layer 12 and the conductive layer 13. As a result, the adhesion between the adhesion layer 12 and the conductive layer 13 is maintained, and the conductive layer 13 does not peel off from the adhesion layer 12.

[0037] Thus, since the adhesion layer 12 is located between the barrier layer 11 and the conductive layer 13, and the adhesion layer 12 is in direct contact with the barrier layer 11 and the conductive layer 13, the adhesion layer 12 enhances the adhesion between the barrier layer 11 and the conductive layer 13. As a result, even if the barrier layer 11 is located between the groove 4 of the insulator 3 and the conductive layer 13, the bonding state between the groove 4 of the insulator 3 and the conductive layer 13 is stabilized via the adhesion layer 12.

[0038] Therefore, for example, in the manufacturing process of the wiring 10 (particularly the process of laminating the conductive layer 13 containing Cu onto the barrier layer 11 located in the recess of the insulator 3), the conductive layer 13 will not peel off from the barrier layer 11, and the conductive layer 13 will not fall out of the groove 4. Furthermore, even when using the conductive film 1A (for example, in a high-temperature environment of 150°C), the conductive layer 13 will not peel off from the barrier layer 11, and the conductive layer 13 will not fall out of the groove 4.

[0039] Furthermore, the weight ratio of Ni contained in the adhesion layer 12 (the NiCuTi alloy which is the main component of the adhesion layer 12) is larger than the weight ratio of Cu contained in the adhesion layer 12. The weight ratio of Ni contained in the adhesion layer 12 is larger than the weight ratio of Ti contained in the adhesion layer 12. This strengthens the chemical interaction between titanium (Ti) contained in the barrier layer 11 and nickel (Ni) contained in the NiCuTi alloy which is the main component of the adhesion layer 12. Similarly, this strengthens the chemical interaction between nickel (Ni) contained in the adhesion layer 12 (the NiCuTi alloy) and copper (Cu) contained in the conductive layer 13. As a result, the adhesion between the barrier layer 11 and the conductive layer 13 can be further improved via the adhesion layer 12.

[0040] In the first embodiment, the weight ratio of Ni in the NiCuTi alloy contained in the adhesion layer 12 is 62% for example. The weight ratio of Cu in the NiCuTi alloy contained in the adhesion layer 12 is 35% for example. The weight ratio of Ti in the NiCuTi alloy contained in the adhesion layer 12 is 3% for example.

[0041] [Modification 1 of First Embodiment] The wiring 10 exemplified in the above first embodiment includes the barrier layer 11, the adhesion layer 12, the conductive layer 13, and the coating layer 14, but is not limited to such a configuration. As in the modification shown in FIG. 4, the wiring 10 may further include an underlayer 15.

[0042] As shown in FIG. 4, the underlayer 15 is located inside the groove 4. Specifically, the underlayer 15 is located between the first barrier layer 11 and the first insulator 3. The underlayer 15 is in direct contact with the first barrier layer 11 and the first insulator 3.

[0043] The underlayer 15 contains a NiCuTi alloy. This NiCuTi alloy is, for example, a metal material constituting a target placed inside a sputtering apparatus (not shown). That is, the underlayer 15 is made of the same metal material as the adhesion layer 12. By arranging the underlayer 15 between the barrier layer 11 and the insulator 3, the adhesion between the barrier layer 11 and the wall surface of the groove 4 in the insulator 3 can be improved.

[0044] [Second Embodiment] The following describes a wiring board according to the second embodiment of this disclosure. As an example of this wiring board, a semiconductor interposer 1B is shown in Figure 5. The wiring board according to the second embodiment of this disclosure is not limited to being used as an interposer as an intermediate member, and it is also possible to use the same configuration as reference numeral 1B shown in Figure 5 as the wiring board itself.

[0045] As shown in Figure 5, the interposer 1B (wiring board) according to the second embodiment comprises a layered first insulator 21, a plurality of conductive wirings 30, a layered second insulator 22, holes 25 provided in the second insulator 22, vias 40, and a plurality of mounting portions 50. Each component will be described in detail below.

[0046] (First Insulator) The first insulator 21 is made of a resin material that has insulating and permeable properties. The thickness of the first insulator 21 is, for example, 2 μm or more and 50 μm or less. Also, the thickness of the first insulator 21 is greater than the depth of the groove 23.

[0047] As shown in Figure 5, a plurality of grooves 23 are formed on the lower surface of the first insulator 21. The grooves 23 have a bottomed shape that is recessed upwards toward the first insulator 21.

[0048] In this embodiment, the side surface of the groove 23 is tapered, widening downward from the bottom surface of the groove 23. Specifically, in the thickness direction of the insulator, the side surface of the groove 23 is inclined downward from the bottom surface of the groove 23 towards the left or right side of the paper in Figure 5. Note that the side surface of the groove 23 does not necessarily have to be tapered.

[0049] The groove width of the groove portion 23 is, for example, 0.5 μm or more and 20 μm or less. The depth of the groove portion 23 is, for example, 0.8 μm or more and 4.0 μm or less. The aspect ratio of the groove portion 23 (the value obtained by dividing the depth dimension of the groove portion 23 by the groove width dimension) is, for example, 0.1 or more.

[0050] An opening 24 is formed on the upper side of the first insulator 21. This opening 24 is formed, for example, by laser light. In this embodiment, the opening 24 is connected to a groove 23 located on the right side of the page in Figure 5.

[0051] (Wiring) The wiring 30 is made of a conductive material embedded in the groove 23 of the first insulator 21. The line width of the wiring 30 is, for example, 0.5 μm or more and 20 μm or less. The spacing between adjacent wirings 30 is, for example, 1 μm or more and 600 μm or less.

[0052] As shown in Figure 5, the wiring 30 illustrated in the second embodiment has a first barrier layer 31, a first adhesion layer 32, and a first conductive layer 33. The wiring 30 of the second embodiment does not have the coating layer 14 shown in the first embodiment. However, the wiring 30 of the second embodiment may have a coating layer 14. If the wiring 30 has a coating layer 14, the corrosion resistance of the wiring 30 is improved.

[0053] (First Barrier Layer) As shown in Figure 5, the first barrier layer 31 is located within the groove 23. The first barrier layer 31 is in direct contact with the bottom and side surfaces of the groove 23. The first barrier layer 31 is formed on the bottom and side surfaces of the groove 23, for example, by sputtering. The thickness of the first barrier layer 31 is, for example, 0.005 μm or more and 0.1 μm or less (5 nm or more and 100 nm or less). The first barrier layer 31 may be formed by a method other than sputtering.

[0054] The first barrier layer 31 contains Ti. A specific example of the first barrier layer 31 is titanium nitride (TiN) formed by sputtering. By placing this first barrier layer 31 between the first insulator 21 (bottom and side surfaces of the groove portion 23) and the first conductive layer 33, oxidation of copper contained in the first conductive layer 33 is prevented in high-temperature environments (e.g., 150°C), and Cu generated by oxidation is also prevented. ２＋ This makes it possible to prevent ions from diffusing into the insulator. As a result, the increase in resistance in the wiring 30 can be reduced.

[0055] (First conductive layer) As shown in Figure 5, the first conductive layer 33 is located within the groove 23. Specifically, the first conductive layer 33 is laminated on the first adhesion layer 32 and is in direct contact with the first adhesion layer 32. This first conductive layer 33 ensures the conductivity of the wiring 30.

[0056] The first conductive layer 33 contains copper (Cu). The first conductive layer 33 is formed, for example, by electroplating, electroless plating, or vacuum deposition. Although copper is suitable as the main component of the first conductive layer 33, other metal materials other than copper (for example, silver, gold, nickel, or aluminum) may also be included as other components.

[0057] (First adhesion layer) The first adhesion layer 32 is formed, for example, by sputtering. The thickness of the first adhesion layer 32 is, for example, 0.005 μm or more and 0.1 μm or less (5 nm or more and 100 nm or less).

[0058] As shown in Figure 5, the first adhesion layer 32 is laminated on the first barrier layer 31. Specifically, the first adhesion layer 32 is located between the first barrier layer 31 and the first conductive layer 33. The first adhesion layer 32 is in direct contact with both the first barrier layer 31 and the first conductive layer 33.

[0059] The first adhesion layer 32 contains a NiCuTi alloy. This NiCuTi alloy is, for example, a metallic material that constitutes a target installed inside a sputtering apparatus (not shown). The first adhesion layer 32 may also contain small amounts of impurities (i.e., components other than the NiCuTi alloy) generated during the formation process of the first adhesion layer 32 by sputtering.

[0060] In this second embodiment, similar to the first embodiment, the first adhesion layer 32 enhances the adhesion between the first barrier layer 31 and the first conductive layer 33. As a result, even if the first barrier layer 31 is located between the groove 23 of the first insulator 21 and the first conductive layer 33, the bonding state between the groove 23 of the first insulator 21 and the first conductive layer 33 can be stabilized via the first adhesion layer 32. Furthermore, by stabilizing the bonding state between the groove 23 of the first insulator 21 and the first conductive layer 33, the durability of the wiring 30 located in the groove 23 can be increased.

[0061] The weight ratio of Ni in the first adhesion layer 32 (the NiCuTi alloy, which is the main component of the first adhesion layer 32) is greater than the weight ratio of Cu in the first adhesion layer 32. The weight ratio of Ni in the first adhesion layer 32 is greater than the weight ratio of Ti in the first adhesion layer 32. As a result, the chemical interaction between titanium (Ti) in the first barrier layer 31 and nickel (Ni) in the NiCuTi alloy, which is the main component of the first adhesion layer 32, is strengthened. Similarly, the chemical interaction between nickel (Ni) in the first adhesion layer 32 (NiCuTi alloy) and copper (Cu) in the first conductive layer 33 is strengthened. As a result, the adhesion between the first barrier layer 31 and the first conductive layer 33 can be further improved via the first adhesion layer 32.

[0062] In the second embodiment, the weight ratio of Ni in the NiCuTi alloy contained in the adhesion layer is, for example, 62%. The weight ratio of Cu in the NiCuTi alloy contained in the adhesion layer is, for example, 35%. The weight ratio of Ti in the NiCuTi alloy contained in the adhesion layer is, for example, 3%.

[0063] (Second insulator) As shown in Figure 5, the second insulator 22 is formed below the first insulator 21. The first insulator 21 is made of a resin material that has insulating and permeable properties. The thickness of the second insulator 22 is, for example, 5 μm or more and 300 μm or less. More preferably, the thickness of the second insulator 22 is, for example, 25 μm or more and 300 μm or less.

[0064] (Hole) As shown in Figure 5, the hole 25 is formed in the second insulator 22. The hole 25 penetrates the second insulator 22 in the thickness direction (vertical direction). The hole 25 is connected to the groove 23 of the first insulator 21. In cross-sectional view, the upper part of the hole 25 becomes narrower as you move from the lower side to the upper side of the hole 25. The shape of the hole 25 in top view or bottom view is not particularly limited and may be circular or polygonal, for example.

[0065] (Via section) As shown in Figure 5, the via section 40 is located within the hole 25 of the second insulator 22. Specifically, the via section 40 is made of a conductive material provided within the hole 25. The via section 40 is connected to the wiring 30 located in the groove 23.

[0066] The via section 40 includes a second barrier layer 41, a second adhesion layer 42, and a second conductive layer 43. The specific configuration of each layer will be described in detail below. In the following, the second barrier layer 41 and the second conductive layer 43 will be described first, followed by the second adhesion layer 42.

[0067] (Second Barrier Layer) As shown in Figure 5, the second barrier layer 41 is laminated on the wall surface of the second insulator 22 within the hole 25. That is, the second barrier layer 41 is in direct contact with the wall surface of the second insulator 22 within the hole 25. The second barrier layer 41 is formed in the hole 25 by, for example, sputtering. The thickness of the second barrier layer 41 is, for example, 0.005 μm or more and 0.1 μm or less (5 nm or more and 100 nm or less). The second barrier layer 41 may be formed by a method other than sputtering.

[0068] The second barrier layer 41 contains Ti. A specific example of the second barrier layer 41 is titanium nitride (TiN) formed by sputtering. Generally, the second barrier layer 41 containing Ti, which has high corrosion resistance, is located within the pores 25 of the second insulator 22, thereby suppressing the oxidation of Cu contained in the second conductive layer 43. ２＋ The ions are prevented from diffusing into the second insulator 22. As a result, the increase in resistance in the via portion 40 is reduced.

[0069] (Second conductive layer) As shown in Figure 5, the second conductive layer 43 is laminated on the second adhesion layer 42 and is in direct contact with the second adhesion layer 42. This second conductive layer 43 ensures the conductivity of the via portion 40.

[0070] The second conductive layer 43 contains copper (Cu). The conductive layer is formed, for example, by electroplating, electroless plating, or vacuum deposition. Although copper is suitable as the main component of the conductive layer, other metal materials other than copper (for example, silver, gold, nickel, or aluminum) may be included as other components.

[0071] (Second adhesion layer) The second adhesion layer 42 is formed, for example, by sputtering. The thickness of the second adhesion layer 42 is, for example, 0.005 μm or more and 0.1 μm or less (5 nm or more and 100 nm or less).

[0072] The second adhesion layer 42 is laminated on the second barrier layer 41. Specifically, the second adhesion layer 42 is located between the second barrier layer 41 and the second conductive layer 43. The second adhesion layer 42 is in direct contact with both the second barrier layer 41 and the second conductive layer 43.

[0073] The second adhesion layer 42 contains a NiCuTi alloy. This NiCuTi alloy is, for example, a metallic material that constitutes a target installed inside a sputtering apparatus (not shown). The second adhesion layer 42 may also contain small amounts of impurities (i.e., components other than the NiCuTi alloy) that are generated during the formation process of the second adhesion layer 42 by sputtering.

[0074] In this second embodiment, the second adhesion layer 42 of the via portion 40 enhances the adhesion between the second barrier layer 41 and the second conductive layer 43. As a result, even if the second barrier layer 41 is located between the hole portion 25 of the second insulator 22 and the second conductive layer 43, the bonding state between the hole portion 25 of the second insulator 22 and the second conductive layer 43 can be stabilized via the second adhesion layer 42. Furthermore, since the bonding state between the hole portion 25 of the second insulator 22 and the second conductive layer 43 is stabilized, the durability of the via portion 40 located in the hole portion 25 can be increased.

[0075] The weight ratio of Ni in the second adhesion layer 42 (the NiCuTi alloy, which is the main component of the second adhesion layer 42) is greater than the weight ratio of Cu in the second adhesion layer 42. The weight ratio of Ni in the second adhesion layer 42 is greater than the weight ratio of Ti in the second adhesion layer 42. As a result, the chemical interaction between titanium (Ti) in the second barrier layer 41 and nickel (Ni) in the NiCuTi alloy, which is the main component of the second adhesion layer 42, is strengthened. Similarly, the chemical interaction between nickel (Ni) in the second adhesion layer 42 (NiCuTi alloy) and copper (Cu) in the second conductive layer 43 is strengthened. As a result, the adhesion between the second barrier layer 41 and the second conductive layer 43 can be further improved via the second adhesion layer 42.

[0076] In the second embodiment, the weight ratio of Ni in the NiCuTi alloy contained in the second adhesion layer 42 is, for example, 62%. The weight ratio of Cu in the NiCuTi alloy contained in the second adhesion layer 42 is, for example, 35%. The weight ratio of Ti in the NiCuTi alloy contained in the second adhesion layer 42 is, for example, 3%.

[0077] (Mounting section) The mounting section 50 is located on the lower surface of the second conductive layer 43. The mounting section 50 protrudes downward from the lower surface of the second conductive layer 43. The mounting section 50 contains copper (Cu). The mounting section 50 is formed, for example, by electroplating, electroless plating, or vacuum deposition.

[0078] The upper surface of the mounting portion 50 located on the right side of Figure 5 is connected to the lower surface (second conductive layer 43) of the via portion 40. In other words, the wiring 30 and the mounting portion 50 located on the right side of Figure 5 are electrically connected via the via portion 40.

[0079] In this embodiment, the third barrier layer 51 and the third adhesion layer 52 are located between the lower surface of the second insulator 22 and the upper surface of the mounting portion 50. The third barrier layer 51 contains Ti. The third adhesion layer 52 contains a NiCuTi alloy. The third barrier layer 51 is continuous with the second barrier layer 41. The third adhesion layer 52 is continuous with the third adhesion layer 52 located within the hole 25.

[0080] [Modification 1 of the Second Embodiment] In the second embodiment described above, the via portion 40 was shown to have a second barrier layer 41, a second adhesion layer 42, and a second conductive layer 43, but it is not limited to this embodiment. For example, as shown in Modification 1 in Figure 6, the via portion 40 does not have to have a second barrier layer 41 and a second adhesion layer 42. Also, as shown in Figure 6, a third barrier layer 51 and a third adhesion layer 52 do not have to be provided.

[0081] [Modification 2 of the Second Embodiment] The wiring 30 illustrated in the second embodiment above has a first barrier layer 31, a first adhesion layer 32, and a first conductive layer 33, but is not limited to this form. For example, as described in the modification of the first embodiment above (see Figure 4), the wiring 30 may further have a base layer (not shown). Note that the specific configuration of the base layer is the same as the base layer 15 shown in Figure 4, so a detailed explanation thereof is omitted.

[0082] [Summary] In the first disclosure, the conductive film 1A comprises a sheet-like insulator 3 with grooves 4 formed on its upper surface, and wiring 10 located along the grooves 4. The wiring 10 is located within the grooves 4 and has a barrier layer 11 containing Ti, an adhesion layer 12 laminated on the barrier layer 11 and containing a NiCuTi alloy, and a conductive layer 13 laminated on the adhesion layer 12 and containing Cu. The adhesion layer 12 is located between the barrier layer 11 and the conductive layer 13. The adhesion layer 12 is in direct contact with the barrier layer 11 and the conductive layer 13.

[0083] In the first disclosure, a barrier layer 11 containing Ti, which generally has high corrosion resistance, is located within the groove 4 of the insulator 3. This suppresses the oxidation of Cu contained in the conductive layer 13, and Cu ２＋ The ions are prevented from diffusing into the insulator 3. As a result, the increase in resistance in the wiring 10 is reduced.

[0084] Here, the titanium (Ti) contained in the barrier layer 11 and the nickel (Ni) contained in the NiCuTi alloy in the adhesion layer 12 are both first transition elements, and good chemical interactions are observed between them. Furthermore, since the thermal expansion coefficients of titanium (Ti) and nickel (Ni) are relatively similar, stress due to temperature changes is reduced at the interface between the barrier layer 11 and the adhesion layer 12. As a result, the adhesion between the barrier layer 11 and the adhesion layer 12 is maintained, and the adhesion layer 12 does not peel off from the barrier layer 11.

[0085] Furthermore, both nickel (Ni) contained in the NiCuTi alloy in the adhesion layer 12 and copper (Cu) contained in the conductive layer 13 are first transition elements, and good chemical interaction is observed between them. In addition, since the thermal expansion coefficients of nickel (Ni) and copper (Cu) are relatively similar, stress due to temperature changes is reduced at the interface between the adhesion layer 12 and the conductive layer 13. As a result, the adhesion between the adhesion layer 12 and the conductive layer 13 is maintained, and the conductive layer 13 does not peel off from the adhesion layer 12.

[0086] Thus, in the first disclosure, the adhesion layer 12 is located between the barrier layer 11 and the conductive layer 13, and the adhesion layer 12 is in direct contact with the barrier layer 11 and the conductive layer 13, thereby enhancing the adhesion between the barrier layer 11 and the conductive layer 13. As a result, even if the barrier layer 11 is located between the groove 4 of the insulator 3 and the conductive layer 13, the bonding state between the groove 4 of the insulator 3 and the conductive layer 13 is stabilized via the adhesion layer 12.

[0087] Therefore, for example, in the manufacturing process of the wiring 10 (particularly the process of laminating the conductive layer 13 containing Cu onto the barrier layer 11 located in the recess of the insulator 3), the conductive layer 13 will not peel off from the barrier layer 11, and the conductive layer 13 will not fall out of the groove 4. Furthermore, even when using the conductive film 1A (for example, in a high-temperature environment of 150°C), the conductive layer 13 will not peel off from the barrier layer 11, and the conductive layer 13 will not fall out of the groove 4.

[0088] Therefore, in the first disclosure, the bonding state between the groove 4 of the insulator 3 and the conductive layer 13 can be stabilized.

[0089] As a second disclosure, the weight ratio of Ni in the adhesion layer 12 is greater than the weight ratio of Cu in the adhesion layer 12, and the weight ratio of Ni in the adhesion layer 12 is greater than the weight ratio of Ti in the adhesion layer 12. This strengthens the chemical interaction between the titanium (Ti) in the barrier layer 11 and the nickel (Ni) in the NiCuTi alloy, which is the main component of the adhesion layer 12. Similarly, the chemical interaction between the nickel (Ni) in the adhesion layer 12 (NiCuTi alloy) and the copper (Cu) in the conductive layer 13 is strengthened. As a result, the adhesion between the barrier layer 11 and the conductive layer 13 can be further enhanced via the adhesion layer 12.

[0090] As a third disclosure, the wiring 10 further has a coating layer 14 containing Ni that is laminated on the upper surface of the conductive layer 13. Ni generally has excellent durability and corrosion resistance. By laminating such a coating layer 14 containing Ni on the upper surface of the conductive layer 13, the durability and corrosion resistance of the wiring 10 (especially the conductive layer 13) can be improved.

[0091] As a fourth disclosure, the wiring 10 further includes a base layer 15 containing a NiCuTi alloy, the base layer 15 being located between the barrier layer 11 and the insulator 3, and the base layer 15 being in direct contact with the barrier layer 11 and the insulator 3. That is, the base layer 15 contains the same alloy as the NiCuTi alloy contained in the adhesion layer 12. By placing such a base layer 15 between the barrier layer 11 and the insulator 3, the adhesion between the barrier layer 11 and the wall surface of the groove 4 in the insulator 3 can be improved.

[0092] The wiring board (interposer 1B) according to the fifth disclosure comprises a layered first insulator 21 having grooves 23 formed on its lower surface, wiring 30 located along the grooves 23 and in the grooves 23, and a layered second insulator 22 formed on the lower side of the first insulator 21. The wiring 30 is located in the grooves 23 and has a first barrier layer 31 containing Ti, a first adhesion layer 32 laminated on the first barrier layer 31 and containing NiCuTi, and a first conductive layer 33 laminated on the first adhesion layer 32 and containing Cu. The first adhesion layer 32 is located between the first barrier layer 31 and the first conductive layer 33.

[0093] In the fifth disclosure, the first barrier layer 31 containing Ti, which generally has high corrosion resistance, is located in the groove 23 of the first insulator 21. This suppresses oxidation of Cu contained in the first conductive layer 33, and Cu ２＋ ions are prevented from diffusing into the first insulator 21. As a result, an increase in the resistance value of the wiring 30 is reduced.

[0094] Here, titanium (Ti) contained in the first barrier layer 31 and nickel (Ni) contained in the NiCuTi alloy of the first adhesion layer 32 are both first transition elements, and good chemical interaction is exhibited between the two. Furthermore, since the coefficient of thermal expansion of titanium (Ti) and the coefficient of thermal expansion of nickel (Ni) exhibit relatively close characteristics, stress accompanying temperature changes at the interface between the first barrier layer 31 and the first adhesion layer 32 is reduced. As a result, adhesion between the first barrier layer 31 and the first adhesion layer 32 is maintained.

[0095] Further, nickel (Ni) contained in the NiCuTi alloy of the first adhesion layer 32 and copper (Cu) contained in the first conductive layer 33 are both first transition elements, and good chemical interaction is exhibited between the two. Furthermore, since the coefficient of thermal expansion of nickel (Ni) and the coefficient of thermal expansion of copper (Cu) exhibit relatively close characteristics, stress accompanying temperature changes at the interface between the first adhesion layer 32 and the first conductive layer 33 is reduced. As a result, adhesion between the first adhesion layer 32 and the first conductive layer 33 is maintained.

[0096] As described above, in the fifth disclosure, the first adhesion layer 32 is located between the first barrier layer 31 and the first conductive layer 33, and the first adhesion layer 32 is in direct contact with the first barrier layer 31 and the first conductive layer 33, so the first adhesion layer 32 improves adhesion between the first barrier layer 31 and the first conductive layer 33. Accordingly, even if the first barrier layer 31 is located between the groove 23 of the first insulator 21 and the first conductive layer 33, the bonding state between the groove 23 of the first insulator 21 and the first conductive layer 33 can be stabilized via the first adhesion layer 32. Furthermore, in the fifth disclosure, by stabilizing the bonding state between the groove 23 of the first insulator 21 and the first conductive layer 33, the durability of the wiring 30 located in the groove 23 can be improved.

[0097] As a sixth disclosure, the weight ratio of Ni in the first adhesion layer 32 is greater than the weight ratio of Cu in the first adhesion layer 32, and the weight ratio of Ni in the first adhesion layer 32 is greater than the weight ratio of Ti in the first adhesion layer 32. This strengthens the chemical interaction between titanium (Ti) in the first barrier layer 31 and nickel (Ni) in the NiCuTi alloy, which is the main component of the first adhesion layer 32. Similarly, the chemical interaction between nickel (Ni) in the first adhesion layer 32 (NiCuTi alloy) and copper (Cu) in the first conductive layer 33 is strengthened. As a result, the adhesion between the first barrier layer 31 and the first conductive layer 33 can be further improved via the first adhesion layer 32.

[0098] As a seventh disclosure, the wiring 30 further includes a base layer containing a NiCuTi alloy (having the same configuration as the base layer 15 shown in Figure 4), the base layer being located between the first barrier layer 31 and the first insulator 21, and the base layer being in direct contact with the first barrier layer 31 and the first insulator 21. By placing such a base layer between the first barrier layer 31 and the first insulator 21, the adhesion between the first barrier layer 31 and the wall surface of the groove 23 in the first insulator 21 can be improved.

[0099] The eighth disclosure further includes a hole 25 formed in the second insulator 22 and connected to a groove 23, and a via 40 located in the hole 25 and connected to the wiring 30. The via 40 is laminated on the wall surface of the second insulator 22 within the hole 25 and has a second barrier layer 41 containing Ti, a second adhesion layer 42 laminated on the second barrier layer 41 and containing a NiCuTi alloy, and a second conductive layer 43 laminated on the second adhesion layer 42 and containing Cu. The second adhesion layer 42 is located between the second barrier layer 41 and the second conductive layer 43.

[0100] In the eighth disclosure, since the via portion 40 has a second barrier layer 41, oxidation of Cu contained in the second conductive layer 43 is suppressed, Cu ２＋ The ions are prevented from diffusing into the second insulator 22. As a result, the increase in resistance in the via portion 40 is reduced.

[0101] Furthermore, in the eighth disclosure, for the same reasons as explained in the fifth disclosure, the second adhesion layer 42 of the via portion 40 enhances the adhesion between the second barrier layer 41 and the second conductive layer 43. As a result, even if the second barrier layer 41 is located between the hole portion 25 of the second insulator 22 and the second conductive layer 43, the bonding state between the hole portion 25 of the second insulator 22 and the second conductive layer 43 can be stabilized via the second adhesion layer 42. Moreover, in the eighth disclosure, since the bonding state between the hole portion 25 of the second insulator 22 and the second conductive layer 43 is stabilized, the durability of the via portion 40 located in the hole portion 25 can be increased.

[0102] As the ninth disclosure, the weight ratio of Ni in the second adhesion layer 42 is greater than the weight ratio of Cu in the second adhesion layer 42, and the weight ratio of Ni in the second adhesion layer 42 is greater than the weight ratio of Ti in the second adhesion layer 42. This strengthens the chemical interaction between titanium (Ti) in the second barrier layer 41 and nickel (Ni) in the NiCuTi alloy, which is the main component of the second adhesion layer 42. Similarly, the chemical interaction between nickel (Ni) in the second adhesion layer 42 (NiCuTi alloy) and copper (Cu) in the second conductive layer 43 is strengthened. As a result, the adhesion between the second barrier layer 41 and the second conductive layer 43 can be further improved via the second adhesion layer 42.

[0103] In the tenth disclosure, the wiring 30 further includes a base layer containing a NiCuTi alloy, the base layer being located between the second barrier layer 41 and the second insulator 22, and the base layer being in direct contact with the second barrier layer 41 and the second insulator 22. By placing such a base layer between the second barrier layer 41 and the second insulator 22, the adhesion between the second barrier layer 41 and the wall surface of the groove 23 in the second insulator 22 can be improved.

[0104] This disclosure is industrially applicable as a conductive film and wiring substrate.

[0105] 1A: Conductive film 2: Substrate 3: Insulator 4: Groove 10: Wiring 11: Barrier layer 12: Adhesion layer 13: Conductive layer 14: Coating layer 15: Underlayment layer 1B: Interposer (wiring board) 21: First insulator 22: Second insulator 23: Groove 24: Opening 25: Hole 30: Wiring 31: First barrier layer 32: First adhesion layer 33: First conductive layer 40: Via 41: Second barrier layer 42: Second adhesion layer 43: Second conductive layer 50: Mounting section 51: Third barrier layer 52: Third adhesion layer

Claims

1. A conductive film comprising: a sheet-like insulator having grooves formed on its upper surface; and wiring positioned along the grooves, wherein the wiring has a barrier layer located within the grooves and containing Ti; an adhesion layer laminated on the barrier layer and containing a NiCuTi alloy; and a conductive layer laminated on the adhesion layer and containing Cu, wherein the adhesion layer is located between the barrier layer and the conductive layer, and the adhesion layer is in direct contact with the barrier layer and the conductive layer.

2. A conductive film according to claim 1, wherein the weight ratio of Ni contained in the adhesion layer is greater than the weight ratio of Cu contained in the adhesion layer, and the weight ratio of Ni contained in the adhesion layer is greater than the weight ratio of Ti contained in the adhesion layer.

3. A conductive film according to claim 1 or 2, wherein the wiring is laminated on the upper surface of the conductive layer and further comprises a coating layer containing Ni.

4. A conductive film according to claim 1, wherein the wiring further comprises a base layer containing a NiCuTi alloy, the base layer is located between the barrier layer and the insulator, and the base layer is in direct contact with the barrier layer and the insulator.

5. A wiring substrate comprising: a layered first insulator having grooves formed on its lower surface; wiring positioned along the grooves; and a layered second insulator formed on the lower side of the first insulator, wherein the wiring has a first barrier layer located within the grooves and containing Ti; a first adhesion layer laminated on the first barrier layer and containing NiCuTi; and a first conductive layer laminated on the first adhesion layer and containing Cu, the first adhesion layer being located between the first barrier layer and the first conductive layer, and the first adhesion layer being in direct contact with the first barrier layer and the first conductive layer.

6. A wiring board according to claim 5, wherein the weight ratio of Ni contained in the first adhesion layer is greater than the weight ratio of Cu contained in the first adhesion layer, and the weight ratio of Ni contained in the first adhesion layer is greater than the weight ratio of Ti contained in the first adhesion layer.

7. A wiring board according to claim 5 or 6, wherein the wiring further comprises a base layer containing a NiCuTi alloy, the base layer is located between the first barrier layer and the first insulator, and the base layer is in direct contact with the first barrier layer and the first insulator.

8. A wiring board according to claim 5 or 6, further comprising: a hole formed in the second insulator and connected to the groove; and a via located in the hole and connected to the wiring, wherein the via has: a second barrier layer containing Ti and laminated on the wall surface of the second insulator within the hole; a second adhesion layer containing a NiCuTi alloy and laminated on the second barrier layer; and a second conductive layer containing Cu and laminated on the second adhesion layer, the second adhesion layer being located between the second barrier layer and the second conductive layer.

9. A wiring board according to claim 7, wherein the weight ratio of Ni contained in the second adhesion layer is greater than the weight ratio of Cu contained in the second adhesion layer, and the weight ratio of Ni contained in the second adhesion layer is greater than the weight ratio of Ti contained in the second adhesion layer.

10. A wiring board according to claim 8 or 9, wherein the wiring further comprises a base layer containing a NiCuTi alloy, the base layer is located between the second barrier layer and the second insulator, and the base layer is in direct contact with the second barrier layer and the second insulator.

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