JP5561057B2 - Electronic component and manufacturing method thereof - Google Patents

Description

  The present invention relates to an electronic component having a structure in which an electrode is formed on a substrate, such as an acoustic wave device, and more particularly to an electronic component having an electrode in which a plurality of electrode layers are laminated and a method for manufacturing the same.

  In an electronic component, various electrodes are formed on a substrate. For example, in a surface acoustic wave device, a wiring electrode, an under bump metal electrode, a pad electrode, and the like are formed in addition to a functional electrode that functions as an electronic component such as an IDT electrode.

  The following Patent Document 1 discloses a surface acoustic wave element as an example of such an electronic component.

  FIG. 13 is a partially cutaway front view for explaining the electrode structure of the surface acoustic wave element described in Patent Document 1. FIG. In the surface acoustic wave element 1001, a wiring electrode 1003 is formed on a substrate 1002. The wiring electrode 1003 is electrically connected to the IDT electrode 1004 indicated by a broken line at a portion not shown. One end of the wiring electrode 1003 is connected to the pad electrode 1005. The wiring electrode 1003 is made of Al. The pad electrode 1005 includes first to third electrode layers 1005a to 1005c. The first electrode layer 1005a is made of Al, and is integrally formed in the same process as the wiring electrode 1003. A second electrode layer 1005b made of Ti or Cu is laminated on the first electrode layer 1005a, and a third electrode layer 1005c made of Au is laminated on the second electrode layer 1005b. That is, from the top, these metal films are laminated in the order of Au / Ti / Al or Au / Cu / Al, and the pad electrode 1005 is formed.

JP 2004-356671 A

  As in the surface acoustic wave element 1001 described in Patent Document 1, conventionally, in a pad electrode or a wiring electrode other than the functional electrode, an electrode is formed by a laminated metal film formed by laminating a plurality of metal films. There are many. This is to improve conductivity, bonding property, solder wettability and the like by selecting a metal material.

  On the other hand, in the manufacturing process of an electronic component such as the surface acoustic wave element 1001, it may be exposed to a high temperature of 170 ° C or higher. For example, in order to reduce the contact resistance between the electrode layers, annealing may be performed at 270 ° C. or higher. Alternatively, when packaging an electronic component using a thermosetting resin, the electronic component may be exposed to a temperature of 200 ° C. or higher when the thermosetting resin is cured.

  When exposed to such a high temperature, in a laminated metal film made of Au / Ti / Al or Au / Cu / Al, Au and Al diffuse between the electrode layer made of Au and the electrode layer made of Al. It was apt. For this reason, the resistance of the wiring electrode may increase or vary. In addition, when an external terminal such as a bump is formed on the pad electrode, the adhesion between the pad electrode and the external terminal tends to deteriorate.

  An object of the present invention is to provide an electronic component that eliminates the above-described drawbacks of the prior art and suppresses metal diffusion between a plurality of electrode layers, and a method for manufacturing the same.

Electronic component according to the first aspect of the present gun includes a substrate and, and an electrode formed on said substrate, said electrodes includes a first electrode layer made of Al or Al alloy, the first electrode layer A second electrode layer made of Cu, a third electrode layer made of Ti, laminated on a surface of the second electrode layer opposite to the first electrode layer, and and the third electrode layer and the second electrode layer have a fourth electrode layer made of a metal other than laminated and and Ti on a surface opposite to constitute the fourth electrode layer The metal is one metal selected from the group consisting of Pt, Au, Ag, W, Ta, Pd, Mo, Ni, and Cu, or an alloy mainly composed of the metal.

  In another specific aspect of the electronic component according to the present invention, the Al alloy is at least one selected from the group consisting of Al, Cu, Ti, Ni, Si, Mg, Ag, Au, Zn, and Cr. Contains seed metals.

  In still another specific aspect of the electronic component according to the present invention, the thickness of the second electrode layer made of Cu is in the range of 10 nm to 100 nm.

  In still another specific aspect of the electronic component according to the present invention, the thickness of the third electrode layer made of Ti is in the range of 10 nm to 100 nm.

The second electronic components according to the invention of the present gun includes a substrate and, and an electrode formed on said substrate, said electrodes includes a first electrode layer made of Al or Al alloy, the first electrode A second electrode layer made of Cu, and a third electrode layer made of Ti, laminated on a surface of the second electrode layer opposite to the first electrode layer, And a fourth electrode layer made of a metal other than Ti, which is laminated on a surface of the third electrode layer opposite to the second electrode layer, and the electrode is formed on the substrate. It is a pad electrode, an under bump metal layer or a wiring electrode, and a functional electrode which functions as an electronic component is formed on the substrate in addition to the electrode constituting the pad electrode, the under bump metal layer or the wiring layer. . In this case, diffusion of Al and Cu can be reliably suppressed in the pad electrode, the under bump metal layer, or the wiring electrode.

  In still another specific aspect of the electronic component according to the present invention, the functional electrode is an IDT electrode, and an elastic wave is excited by the IDT electrode.

  According to the electronic component and the manufacturing method thereof according to the present invention, the first electrode layer made of Al or an Al alloy / the second electrode layer made of Cu / the third electrode layer made of Ti / made of a metal other than Ti Since the fourth electrode layer is laminated in this order from the top or the bottom, it is possible to reliably suppress the diffusion of Al and a metal other than Ti constituting the fourth electrode layer. That is, even if aging by heating or heating to cure the thermosetting resin is performed, the laminated structure composed of the second electrode layer made of Cu and the third electrode layer made of Ti is the first made of Al or Al alloy. Since it exists between the 1st electrode layer and the 4th electrode layer which consists of metals other than Ti, the spreading | diffusion with metals other than Al and Ti can be suppressed reliably.

  Therefore, the contact resistance between the electrode layers can be lowered and stabilized, and an electronic component excellent in the bonding reliability between the electrode layers can be provided.

It is front sectional drawing for demonstrating the principal part of the electrode structure of the electronic component of the 1st Embodiment of this invention. (A)-(c) is each front sectional drawing for demonstrating the manufacturing method of the electronic component of the 1st Embodiment of this invention. (A)-(c) is each front sectional drawing for demonstrating the manufacturing method of the electronic component of the 1st Embodiment of this invention. It is a figure which shows the relationship between the aging temperature at the time of the aging by heating in 1st Embodiment, and the contact resistance between electrode layers. (A) And (b) is the optical microscope photograph for demonstrating the electrode diffusion state after aging at the temperature of 300 degreeC in the 1st Embodiment of this invention, and the typical which shows the cross-section of (a) It is sectional drawing. (A) And (b) is an optical micrograph for demonstrating the electrode diffusion state after aging at the temperature of 300 degreeC in the 1st comparative example of this invention, and the typical which shows the cross-section of (a) It is sectional drawing. (A) And (b) is the typical example which shows the optical microscope photograph for demonstrating the electrode diffusion state after aging at the temperature of 300 degreeC in the 2nd comparative example of this invention, and the cross-section of (a). It is sectional drawing. (A)-(c) is each front sectional drawing for demonstrating the manufacturing method of the electronic component concerning the 2nd Embodiment of this invention. (A)-(d) is each front sectional drawing for demonstrating the manufacturing method of the electronic component concerning the 2nd Embodiment of this invention. (A)-(c) is each front sectional drawing for demonstrating the manufacturing method of the electronic component concerning the 3rd Embodiment of this invention. (A) And (b) is each front sectional drawing for demonstrating the manufacturing method of the electronic component of 3rd Embodiment. (A) And (b) is each front sectional drawing for demonstrating the manufacturing method of the electronic component of 3rd Embodiment. It is typical sectional drawing which shows the electrode structure of the conventional electronic component.

  Hereinafter, the present invention will be clarified by describing specific embodiments of the present invention with reference to the drawings.

(First embodiment)
A method for manufacturing a surface acoustic wave element as an electronic component according to the first embodiment of the present invention will be described.

  As shown in FIG. 2A, a 10 nm thick Ti film 11 and a 150 nm thick AlCu film are sequentially formed on the piezoelectric substrate 2 and patterned. Thereby, the IDT electrode 3 made of a laminated metal film in which the AlCu film 12 is laminated is formed on the Ti film 11. At the same time, a first electrode layer 12A made of an AlCu film is laminated on the Ti film 11 in the wiring electrode formation portion A.

  The Cu concentration in the AlCu alloy in the first electrode layer 12A is 1% by weight.

  In the present embodiment, the Ti film 11 and the AlCu alloy film are formed and patterned by a vapor deposition-lift-off method, but other photolithography methods such as a sputtering-dry etching method may be used.

  The IDT electrode 3 and the Ti film 11 and the first electrode layer 12A that form the wiring electrode are desirably formed in the same process as in this embodiment. Thereby, the manufacturing process can be simplified. However, the IDT electrode 3, the Ti film 11 for forming the wiring electrode, and the first electrode layer 12A may be formed in separate steps.

  Next, the insulating film 13 is formed over the first electrode layer 12A. The insulating film 13 is provided to prevent a short circuit between the intersecting upper and lower electrodes.

  The insulating film 13 is made of polyimide in this embodiment, but may be formed of other organic material or inorganic material. In the present embodiment, the film thickness of the insulating film 13 made of polyimide is 2 μm.

  In forming the insulating film 13, polyimide is applied and cured. But the formation method of the insulating film 13 may be other than the coating method.

  Next, as shown in FIG. 2C, a Cu film having a thickness of 10 nm, a Ti film having a thickness of 250 nm, and an Au film having a thickness of 550 nm are sequentially formed and patterned by an evaporation-lift-off method. In this way, in the wiring electrode formation portion A, the second electrode layer 14A made of a Cu film, the third electrode layer 15A made of a Ti film, and the fourth electrode layer 16A made of an Au film are laminated. Also on the insulating film 13, an electrode layer 14B made of a Cu film, an electrode layer 15B made of Ti, and an electrode layer 16B made of an Au film are laminated. At the same time, an electrode layer 14C made of a Cu film, an electrode layer 15C made of Ti, and an electrode layer 16C made of an Au film are also laminated in the region B where the pad electrode is formed.

  Thus, the wiring electrode 4 having a structure in which the first to fourth electrode layers 12A, 14A, 15A, and 16A are laminated is formed as the first embodiment of the present invention shown in FIG. .

  On the other hand, in the portion where the insulating film 13 is formed, there is a short circuit between the first electrode layer 12A and the electrodes formed on the insulating film 13 and composed of the second to fourth electrode layers 14B to 16B. It is prevented. Moreover, a pad electrode is formed by the laminated metal film composed of the electrode layers 14C to 16C.

  The deposition and patterning of the Cu film, Ti film, and Au film are not limited to the vapor deposition-lift-off method, and other photolithography methods such as a sputtering-dry etching method may be used.

Next, as shown in FIG. 3A, a dielectric thin film 17 is formed. The dielectric thin film 17 is provided to protect the IDT electrode 3. That is, the dielectric thin film 17 is a protective film. In this embodiment, a SiO ₂ film having a thickness of 20 nm is formed as the dielectric thin film 17 by a sputtering-dry etching method. However, the material constituting the dielectric thin film 17 is not limited to SiO ₂ . Further, the dielectric thin film 17 may be formed by a method other than the sputtering-dry etching method.

  Next, in the wiring electrode, aging is performed to reduce the contact resistance between the first to fourth electrode layers 12A and 14A to 16A. In order to reduce the contact resistance of the contact portion between the Ti film and the AlCu alloy film, it is necessary to perform aging at a heating temperature of 270 ° C. or higher. The contact resistance between the first to fourth electrode layers 12A and 14A to 16A can be stabilized by aging. As a result of this aging, as indicated by arrows in FIG. 3B, diffusion of Al and Au tends to proceed in the portion where the first to fourth electrode layers 12A and 14A to 16A are laminated. As will be described later, diffusion is suppressed.

  Next, as shown in FIG. 3C, bumps 18 made of Au are formed on the pad electrode 19.

  As described above, various electrodes of the surface acoustic wave element 1 can be formed on the substrate 2.

  FIG. 4 is a diagram showing the relationship between the aging temperature and the contact resistance. It can be seen that when the aging temperature, that is, the heating temperature is 270 ° C. or higher, the contact resistance is lowered. Preferably, it can be seen that by setting the aging temperature to 300 ° C. or higher, the contact resistance can be sufficiently lowered, and the variation in contact resistance due to the variation in temperature can be reduced.

  The surface acoustic wave element 1 according to this embodiment is characterized by the structure of the wiring electrode 4. That is, as shown in an enlarged view in FIG. 1, in the wiring electrode 4, on the Ti film 11, the first electrode layer 12A made of AlCu alloy, the second electrode layer 14A made of Cu, and the third electrode made of Ti. The electrode layer 15A and the fourth electrode layer 16A made of Au are laminated in this order from the bottom. Therefore, even if aging is performed at a temperature of 270 ° C. or higher in order to reduce the contact resistance, diffusion of Al and Au can be prevented, and a high-quality wiring electrode free from an AuAl alloy can be formed. . This will be described with reference to FIGS.

  FIG. 5A is an optical micrograph showing the wiring electrode 4 portion of the surface acoustic wave element obtained by the embodiment. FIG. 5B schematically shows a laminated structure of the wiring electrode 4 and shows the same structure as FIG.

  For comparison with the above embodiment, a second comparative example having a stacked structure shown in FIG. 6B and a third comparative example having a stacked structure shown in FIG. 7B were prepared.

  In the second comparative example shown in FIG. 6B, the second electrode layer is formed from the Cu film between the first electrode layer made of AlCu alloy and the third electrode layer made of Ti. Except for the absence, it was the same as the above embodiment.

  In the third embodiment shown in FIG. 7B, the fourth electrode layer 39 made of a Pt film is laminated instead of Au, and the first electrode layer 12A is not formed. This is the same as in the first embodiment.

  Optical micrographs of the wiring electrodes of the first and second comparative examples are shown in FIGS. 6 (a) and 7 (a), respectively. FIGS. 5A, 6A, and 7A are optical micrographs (100 times) viewed from above the wiring electrode 4 after aging the wiring electrode 4 at a temperature of 300.degree.

  As is clear from FIG. 6A, it can be seen that AuAl alloys due to the diffusion of Au and Al are scattered in the wiring electrode. On the other hand, in the above-described embodiment shown in FIG. 5A, it can be seen that such an AuAl alloy does not exist, and thus a wiring electrode having a homogeneous structure can be formed.

  Moreover, as shown to Fig.7 (a), when a 4th electrode layer consists of Pt, it turns out that many PtAl alloys have arisen by the diffusion of Al and Pt.

  As described above, also in the second comparative example in which the fourth electrode layer is Pt, it can be seen that the PtAl alloy due to the diffusion of Pt and Al is generated in the wiring electrode in a considerable ratio.

  On the other hand, in the above embodiment, as shown in FIG. 5A, there is no alloy due to metal diffusion as described above.

  This is because the diffusion of Al and Au or Pt interposes the second electrode layer 14A made of Cu film and the third electrode layer 15A made of Ti between the first and fourth electrode layers 12A and 16A. It is thought that it was because it was suppressed by doing.

  In the above embodiment, the fourth electrode layer 16A is made of Au, but is not limited to Au. If the fourth electrode layer 16A is one kind of metal selected from the group consisting of Au, Pt, Ag, W, Ta, Pd, Mo, Ni, and Cu or an alloy mainly composed of the metal, the above-described implementation is performed. The same effect as the form can be obtained.

  The first electrode layer 12A is made of an AlCu alloy, but may be made of Al. In the case of an AlCu alloy, if Al is the main component, that is, if it contains 50% by weight or more of Al, it is not particularly limited. Further, the Ti film 11 and the first electrode layer 12 </ b> A may be formed on B in the region where the pad electrode is to be formed, and the pad electrode may have the same stacked structure as the wiring electrode 4.

(Second Embodiment)
With reference to FIGS. 8A to 8C and FIGS. 9A to 9D, a method for manufacturing a surface acoustic wave device according to the second embodiment of the present invention will be described.

  In the present embodiment, as in the case of the first embodiment, as shown in FIG. 8A, in order to form the IDT electrode 3 on the piezoelectric substrate 20, the Ti film 21 having a thickness of 10 nm and the Cu film 21 are formed. A 150 nm thick AlCu alloy film 22 having a concentration of 1% by weight is formed by evaporation-lift-off and patterned. In the second embodiment as well, in the wiring electrode formation portion A, the first electrode layer 22A made of an AlCu alloy film is formed.

  Next, as in the first embodiment, an insulating film 23 made of polyimide having a thickness of 2 μm is formed. As shown in FIG. 8B, the insulating film 23 is formed on a part of the first electrode layer 22A.

  Next, as shown in FIG. 8C, a Cu film having a thickness of 10 nm, a Ti film having a thickness of 250 nm, and a Pt film having a thickness of 150 nm are formed in this order by the evaporation-lift-off method and patterned. Thereby, the second electrode layer 24A made of Cu and the third electrode made of Ti are formed on the first electrode layer 22A in the portion where the wiring electrode 4 is formed in the same manner as the structure shown in FIG. A fourth electrode layer 26A composed of the layers 25A and Pt is formed. That is, the second to fourth layers are the same as the wiring electrodes 4 of the first embodiment except that the fourth electrode layer 26A is made of Pt instead of Au and has a thickness of 100 nm. Electrode layers 24A to 26A are formed.

  Also in this embodiment, the electrode layer 24B made of Cu, the electrode layer 25B made of Ti, and the electrode layer 26B made of Pt are laminated on the insulating film 23. Also in the portion B where the pad electrode is formed, the electrode layer 24C made of Cu, the electrode layer 25C made of Ti, and the electrode layer 26C made of Pt are laminated.

Thereafter, the center of the upper surface of the electrode layer 26C of the portion B where the pad electrode is to be formed is exposed, and a 20 nm thick dielectric film 27 made of SiO _{2 is} formed by sputtering-dry etching so as to cover other regions. To do.

  Thereafter, aging is performed by maintaining the temperature at 300 ° C. for 2 hours. Due to this aging, as indicated by arrows in FIG. 9B, diffusion of Pt and Al tends to proceed in the portion where the first to fourth electrode layers 22A, 24A, 25A and 26A are laminated. However, the diffusion is reliably suppressed by the presence of the second electrode layer 24A made of Cu and the third electrode layer 25A made of Ti.

  Next, as shown in FIG. 9C, an under bump metal layer 28 is formed on the electrode layer 26C in a portion where the pad electrode B is formed. In this embodiment, as the under bump metal layer, a Ni film having a thickness of 100 nm is formed by a vapor deposition-lift-off method. But other metals may be used and other photography methods, such as sputtering-dry etching methods other than a vapor deposition-lift-off method, may be used.

  Thereafter, as shown in FIG. 9D, bumps 29 made of solder are formed on the under bump metal layer 28. In this embodiment, the bumps 29 are formed using Sn—Ag—Cu solder, but the metal constituting the bumps is not limited to this.

  Also in this embodiment, the diffusion of Pt and Al is reliably suppressed by the presence of the second electrode layer 24A made of Cu and the third electrode layer 25A made of Ti.

(Third embodiment)
The third embodiment relates to a surface acoustic wave element having a package component using a thermosetting resin.

  As shown in FIG. 10A, a piezoelectric substrate 30 is prepared. A 10 nm thick Ti film 33 and a 150 nm thick Al film are sequentially formed on the piezoelectric substrate 30 by a vapor deposition-lift-off method and patterned to obtain the electrode structure shown in FIG. Here, the IDT electrode 31 </ b> A includes a Ti film 33 and an Al film 34. In addition, wiring electrodes are formed on both sides of the IDT electrode 31A. At the positions where the wiring electrodes are formed, the electrode layers 33A and 33A made of Ti, and the first made of Al stacked on the electrode layers 33A and 33A, respectively. Electrode layers 34A, 34A are formed.

  Thereafter, as shown in FIG. 10B, a second electrode layer 35A, 35A made of Cu and a third electrode layer made of Ti is formed on the first electrode layers 34A and 34A, and a third film made of Ti is made of Ti. The electrode layers 36A and 36A and the fourth electrode layers 37A and 37A made of Au and having a thickness of 500 nm are similarly laminated by the vapor deposition-lift-off method. Next, in order to reduce the contact resistance between the electrode layers in the wiring electrodes 31B and 31B, aging is performed at a temperature of 300 ° C. for 2 hours. Even when this aging is performed, the diffusion of Al and Au is reliably suppressed as in the first and second embodiments. Therefore, the contact resistance can be made sufficiently low. Also, AuAl alloy due to diffusion hardly occurs.

  Next, as shown in FIG. 10C, as an exterior resin for forming the package material, an epoxy resin is applied so as to surround the region where the IDT electrode 31A is formed and cured. In this way, the thermosetting resin layer 38 shown in FIG. 10C is formed. The curing temperature of the epoxy resin used is 280 ° C. The epoxy resin is cured by maintaining this curing temperature for 2 hours. Even in this case, the diffusion of Al and Au between the first to fourth electrode layers 34A to 37A is reliably suppressed.

  Next, as shown in FIG. 11A, aging is performed by bonding a cover member 40 made of polyimide so as to close the opening of the thermosetting resin layer 38 and heating to a temperature of 300 ° C. . Also in this heating step, the first to fourth electrode layers 34A to 37A are exposed to a high temperature, but the diffusion is difficult to occur.

  Next, as shown in FIG. 11B, holes 41 and 41 are formed so as to penetrate the cover member 40 and the thermosetting resin layer 38 and expose the upper surfaces of the wiring electrodes 31B and 31B.

  Next, as shown in FIG. 12A, under bump metal layers 42 and 42 made of Ni or Au are formed in the holes 41 and 41. Finally, as shown in FIG. 12B, bumps 43 and 43 made of Sn—Ag—Cu solder are formed on the under bump metal layers 42 and 42.

  In this way, not only the wiring electrodes 31B and 31B but also a plurality of electrode layers constituting the under bump metal layers including the under bump metal layers 42 and 42, by using the electrode structure of the present invention, Al and Diffusion with Au can be reliably suppressed.

  Moreover, not only during aging by heating to reduce the contact resistance between the electrode layers, but also during the heating process for curing the thermosetting resin and the heating process for bonding and curing the cover member, Diffusion of Al and Au between the first to fourth electrode layers can be reliably prevented.

  Also in the third embodiment, as the metal constituting the fourth electrode layer, other metals such as Pt may be used instead of Au as in the first embodiment.

  In the first to third embodiments, the Ti film is formed on the surface of the first electrode layer opposite to the second electrode layer. However, the Ti film may not be formed. Further, other metal films may be laminated. That is, as long as it has a structure in which the first electrode layer to the fourth electrode layer are stacked, a metal film made of another metal film is stacked on the outer surface of the first electrode layer and the outer surface of the fourth electrode layer. May be.

  Furthermore, in the first to third embodiments, the first electrode layer is located below and the fourth electrode layer is located above. Conversely, the first electrode layer made of Al or Al alloy is located above. In addition, the fourth electrode layer may be positioned below. In that case, the second electrode layer in contact with the first electrode layer may be a Cu film.

  In the first to third embodiments, the method for manufacturing the surface acoustic wave element has been described. However, as described above, the present invention is characterized by the laminated structure of the first to fourth electrode layers. Therefore, the electronic component is not particularly limited. Therefore, the substrate does not have to be a piezoelectric substrate, and may be an insulating substrate or a semiconductor substrate.

  Also, the planar shape of the electrode formed on the substrate can be appropriately modified according to the type of electrode. However, the wiring electrode, the under bump metal electrode, or the pad electrode other than the functioning electrode such as the IDT electrode may have the specific electrode structure.

DESCRIPTION OF SYMBOLS 1 ... Surface acoustic wave element 2 ... Piezoelectric substrate 3 ... IDT electrode 4 ... Wiring electrode 5, 9 ... Pad electrode 11 ... Ti film 12 ... AlCu film 12A ... 1st electrode layer 13 ... Insulating film 14A-16A ... 2nd 4th electrode layer 14B-16B, 14C-16C ... Electrode layer 17 ... Dielectric thin film 18 ... Bump 20 ... Substrate 21 ... Ti film 22 ... AlCu alloy film 22A ... 1st electrode layer 23 ... Insulating film 24A-26A ... 2nd-4th electrode layer 24B-26B, 24C-26C ... Electrode layer 27 ... Dielectric film 28 ... Under bump metal layer 29 ... Bump 30 ... Piezoelectric substrate 31A ... IDT electrode 31B ... Wiring electrode 33 ... Ti film 33A ... Electrode layer 34 ... Al film 34A-37A ... 1st-4th electrode layer 38 ... Thermosetting resin layer 39 ... 4th electrode layer 40 ... Cover member 41 ... Hole 42 ... Under bump metal layer 43 ... Bump

Claims (6)

A substrate,
An electrode formed on the substrate,
The electrode is laminated on the first electrode layer made of Al or Al alloy, the first electrode layer, the second electrode layer made of Cu, the first electrode layer of the second electrode layer, Is laminated on the opposite surface and is laminated on the third electrode layer made of Ti and the second electrode layer of the third electrode layer opposite to the second electrode layer, and a metal other than Ti possess fourth and an electrode layer made of a metal constituting the fourth electrode layer has been selected Pt, Au, Ag, W, Ta, Pd, Mo, from the group consisting of Ni and Cu An electronic component which is a kind of metal or an alloy mainly composed of the metal . A substrate,
An electrode formed on the substrate,
The electrode is laminated on the first electrode layer made of Al or Al alloy, the first electrode layer, the second electrode layer made of Cu, the first electrode layer of the second electrode layer, Is laminated on the opposite surface and is laminated on the third electrode layer made of Ti and the second electrode layer of the third electrode layer opposite to the second electrode layer, and a metal other than Ti A fourth electrode layer comprising:
The electrode is a pad electrode, an under bump metal layer or a wiring electrode formed on a substrate, and an electronic component other than the electrode constituting the pad electrode, the under bump metal layer or the wiring layer on the substrate An electronic component in which a functional electrode that functions as an electrode is formed.   The Al alloy according to claim 1 or 2, wherein the Al alloy contains at least one metal selected from the group consisting of Cu, Ti, Ni, Si, Mg, Ag, Au, Zn, and Cr. Electronic components.   The electronic component according to any one of claims 1 to 3, wherein a film thickness of the second electrode layer made of Cu is in a range of 10 nm to 100 nm.   The electronic component according to any one of claims 1 to 4, wherein a film thickness of the third electrode layer made of Ti is in a range of 10 nm to 100 nm. The electronic component according to claim 2 , wherein the functional electrode is an IDT electrode, and an elastic wave is excited by the IDT electrode.

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