JP6250614B2 - Cu laminated film and Cu alloy sputtering target - Google Patents

Description

The present invention relates to a Cu laminated film and a Cu alloy sputtering target.

  Conventionally, ITO thin films and Al thin films have been used for flat panel displays such as liquid crystal panels and organic EL panels, and for touch panel wiring. With the increase in the size of the panel and the miniaturization of the wiring, that is, the narrowing of the width, wiring having a lower electric resistance than before is required. Since Cu exhibits the third lowest electrical resistance after Au and Ag and is less expensive than Au and Ag, a wiring electrode using a film made of pure Cu or a Cu-based alloy has been proposed. However, since Cu has a high affinity with oxygen, it is oxidized by heating in the presence of oxygen and the passage of time, leading to discoloration and an increase in electrical resistance.

  As a technique using Cu, Patent Document 1 proposes a sputtering target used when a protective film is formed on one side or both sides of a Cu wiring film. Specifically, the sputtering target is 8.0% by mass or more and 11.0% by mass or less of Al, 3.0% by mass or more and 5.0% by mass or less of Fe, and 0.5% by mass or more and 2.0% by mass of Ni. Hereinafter, it is shown that Mn is contained in an amount of 0.5% by mass or more and 2.0% by mass or less, with the balance being Cu and inevitable impurities. Further, Patent Document 1 shows that the film made of the Cu alloy serves as a protective film that suppresses discoloration during a weather resistance test that is exposed for 250 hours at a temperature of 60 ° C. and a relative humidity of 90%.

  Patent Document 2 includes 20.0 to 40.0% by mass of nickel as a Cu alloy sputtering target, and any one of Cr, Ti, V, Al, Ta, Co, Zr, Nb, and Mo, or these There has been proposed a Cu alloy sputtering target in which two or more elements are added in a total amount of 1.0 to 10.0% by mass, and the balance is copper and inevitable impurities. Moreover, it is shown that the metal thin film formed using this Cu alloy sputtering target is excellent in oxidation resistance and corrosion resistance compared with Cu etc., and is used as a wiring material and a protective film of a wiring material.

In the display device using the oxide semiconductor layer, the applicant of the present application can also effectively prevent the Cu wiring from being oxidized in the plasma treatment using the gas containing oxygen atoms such as N ₂ O during the formation of the protective film. A structure is proposed in Patent Document 3. That is, a wiring structure including a semiconductor layer of a thin film transistor, a Cu alloy film used for an electrode, and a protective film in order from the substrate side on the substrate, wherein the semiconductor layer is made of an oxide semiconductor, The Cu alloy film has a laminated structure including a first layer (X) and a second layer (Z) in order from the substrate side, and in particular, the second layer (Z) includes Zn, Ni, Ti, Al, Proposing a wiring structure made of a Cu-Z alloy containing 2 to 20 atomic% in total of at least one Z group element selected from the group consisting of Mg, Ca, W, Nb, rare earth elements, Ge, and Mn Yes.

  In Patent Document 4, in a transparent conductive film and a wiring film for a touch panel sensor connected to the transparent conductive film, the wiring film includes at least one alloy element selected from the group consisting of Ni, Zn, and Mn. A Cu alloy (first layer) containing 0.1 to 40 atomic% in total amount and pure Cu or a Cu alloy containing Cu as a main component and having a lower electrical resistivity than the first layer. And a Cu alloy wiring film for a touch panel sensor excellent in oxidation resistance, wherein the second layer is connected to the transparent conductive film. .

JP 2014-156621 A Japanese Patent Application Laid-Open No. 2013-133489 Japanese Patent Application Laid-Open No. 2012-243779 JP 2013-120411 A

  By the way, when patterning a Cu-based film to a submicron size such as wiring, processing by a wet etching method is common. For example, in wet etching processing on the frame wiring of touch panel sensors, an etching solution containing iron chloride, an etching solution containing ammonium persulfate, an etching solution containing hydrogen peroxide, or a mixed acid etching solution containing phosphoric acid, acetic acid, nitric acid, etc. Is used. However, the materials that have been proposed so far have a problem that a good wiring shape cannot be obtained by wet etching using the above etching solution. In particular, No. 1 in Table 1 of Patent Document 4 above. No. 7 Cu-40 at% Ni thin film or No. 7 Since the Cu-20 at% Ni-20 at% Mn thin film shown in No. 29 has a large amount of Ni added, it has oxidation resistance, but the workability by the wet etching method is not taken into account, and it cannot be finely processed.

The present invention was made in view of the above problems, and its object is excellent in oxidation resistance with showing a low electric resistance, and C u alloys that can the be satisfactorily wiring processed by wet etching It is to propose a Cu laminated film including a film, a laminated body having the Cu laminated film, and a sputtering target for forming the Cu alloy film. Hereinafter, the fact that the wiring process can be satisfactorily performed by the wet etching method is sometimes referred to as “excellent wet etching processability”.

The Cu laminated film of the present invention capable of solving the above problems has a film made of pure Cu or a Cu-based alloy as a first layer and a Cu alloy film as a second layer, and the Cu alloy film includes Al, 1 type X element selected from the group which consists of Mn and Sn is included, and Ni is 3.0 atomic% or more and 19.0 atomic% or less (however, when said X element is Sn, 12 atomic% or less) In the case where the balance is made of Cu and inevitable impurities, and the X element is Al, the content of the X element is not less than x atomic% and not more than 40 atomic% determined by the following formula (1), and Ni When the X element is Mn, the content of the X element is x atom% or more and 40 atom% or less obtained from the following formula (1), And the total amount of Ni and X element is 20.0 atomic% or more When the X element is Sn, the content of the X element is x atom% or more and 30 atom% or less obtained from the following formula (1), and the total amount of Ni and X element is 16.0 atom% It has the characteristics in the above place. Hereinafter, the Cu alloy film called "Cu-Ni-X film", in the first layer described above, a film made of Cu-based alloy is sometimes referred to as "Cu-based alloy film."
x = 1.96 × Ni + 1.64 (1)
In the above formula (1), Ni indicates the Ni content in atomic% in the Cu alloy film.

  In a preferred embodiment of the present invention, the thickness of the second layer is 10 nm or more and 200 nm or less.

  In a preferred embodiment of the present invention, the Cu-based alloy in the first layer contains at least one Z element selected from the group consisting of Ti, Mn, Fe, Co, Ni, Ge, and Zn, with the balance being It consists of Cu and inevitable impurities.

  The present invention also includes a laminate having the Cu laminated film on a substrate. Moreover, the present invention includes a wiring electrode, an input device, and a touch panel sensor using the laminate. Furthermore, the present invention includes a Cu alloy sputtering target for forming the Cu—Ni—X film.

  According to the present invention, a Cu—Ni—X film having low electrical resistance and excellent oxidation resistance and wet etching processability; and oxidation resistance comprising the Cu—Ni—X film as an oxidation resistant protective film, for example. And a Cu laminated film excellent in wet etching processability; a laminated body having the Cu laminated film; and a wiring electrode using the laminated body.

FIG. 1 is a schematic cross-sectional view illustrating the configuration of the laminate of the invention. FIG. 2 is a schematic cross-sectional view illustrating another configuration of the laminate of the invention. FIG. 3 is a schematic cross-sectional view illustrating another configuration of the laminate of the invention.

  The inventors of the present invention have made extensive studies to solve the above problems. In order to obtain a Cu alloy film based on Cu exhibiting a low electrical resistance and excellent in oxidation resistance and excellent in wet etching processability, the inventors have intensively studied particularly alloy elements.

  As a result, Cu—Ni containing 3.0 atomic% or more and 19.0 atomic% or less and containing one X element selected from the group consisting of Al, Zn, Mn, and Sn within the range described later. It has been found that if an -X film is used, all of low electrical resistance, excellent oxidation resistance, and excellent wet etching processability can be achieved.

  Hereinafter, the Cu—Ni—X film will be described in detail.

  First, Ni will be described. Ni diffuses in the film, concentrates on the surface, and is further oxidized to form oxidized Ni, thereby protecting the surface of the Cu—Ni—X film by passivation.

  When the Ni content is less than 3.0 atomic%, sufficient oxidation resistance cannot be ensured even when the element X described later is included. Therefore, in this invention, Ni content shall be 3.0 atomic% or more. Hereinafter, the Ni content may be simply referred to as Ni amount. The amount of Ni is preferably 4 atomic% or more. On the other hand, if the amount of Ni exceeds 19.0 atomic%, it is difficult to etch during wiring processing, and a favorable wiring shape cannot be obtained. Therefore, the Ni content is 19.0 atomic% or less. The amount of Ni is preferably 12 atomic percent or less, more preferably 10 atomic percent or less.

  Next, the X element will be described. The elements X, Al, Zn, Mn, and Sn diffuse in the film, concentrate on the surface, and are further oxidized to form oxide X and passivate to protect the surface of the Cu—Ni—X film. . Further, these elements are more easily dissolved in an etching solution such as an iron chloride-containing etching solution than Ni, and contribute to improvement of wet etching processability.

  Among the X elements, Zn and Sn are elements that are easily vaporized in a vacuum. Therefore, when a Cu—Ni—X film is formed by a sputtering method, a composition shift or the like is more likely to occur than Al or Mn. Therefore, from the viewpoint of ease of use, it is preferable to use Al or Mn as the X element.

In order to sufficiently exhibit the effect of the X element, the lower limit of the content of the X element is set as follows according to the Ni amount. That is, the content of the X element is set to x atom% or more obtained from the following formula (1).
x = 1.96 × Ni + 1.64 (1)
In the above formula (1), Ni represents the Ni content in atomic% in the Cu—Ni—X film.

  The upper limit of the content of the X element is not particularly limited. A preferable method for producing the Cu—Ni—X film includes a sputtering method. From the viewpoint of ease of production of a sputtering target used in this sputtering method, the content of the X element is 50 atomic% or less. Is more preferable, and more preferably 40 atomic% or less.

  In the case of Al among the X elements, the upper limit of the content is preferably 50 atomic percent or less. This is because if the Al amount exceeds 50 atomic%, a residue derived from Al oxide is likely to be generated during wiring processing, that is, wet etching processability is likely to deteriorate. The upper limit of the Al content is more preferably 40 atomic% or less.

  In the present invention, the lower limit value of the total amount of Ni and X element is also defined according to the type of X element. In the case where the X element is Zn or Mn, the total amount of Ni and X element is 20.0 from the viewpoint of suppressing the increase in eave width during wiring processing by the amount of change in reflectance before and after the heat treatment and the wet etching method. At least atomic percent. The total amount is preferably 25.0 atomic% or more. On the other hand, from the viewpoint of manufacturability of the sputtering target used for forming the thin film, the total amount is preferably 40.0 atomic% or less.

  In the case where the X element is Al or Sn, the total amount of Ni and X elements is adjusted from the viewpoint of suppressing the increase in eave width during wiring processing by the reflectance change amount before and after the heat treatment and the wet etching method. 0 atomic% or more. The total amount is preferably 20.0 atomic% or more, more preferably 25.0 atomic% or more. On the other hand, from the viewpoint of manufacturability of the sputtering target used for forming the thin film, the total amount is preferably 45.0 atomic% or less, more preferably 43.0 atomic% or less, and further preferably 40.0 atomic%. It is as follows.

  The Cu—Ni—X film contains 3.0 atomic% or more and 19.0 atomic% or less of Ni, and contains one kind of X element selected from the group consisting of Al, Zn, Mn, and Sn as described above. It is included so that the total amount with Ni is equal to or more than the lower limit according to the amount of Ni, and the remaining amount is made of Cu and inevitable impurities.

  The film thickness of the Cu—Ni—X film is not particularly limited. For example, it can be 10 nm or more and 200 nm or less. When forming a laminated film including the Cu-Ni-X film, it is recommended that the film thickness of the Cu-Ni-X film be as described below.

  The present invention also includes a Cu laminated film obtained by laminating a film made of pure Cu or a Cu-based alloy as the first layer and the Cu—Ni—X film as the second layer. In this Cu laminated film, the first layer is formed as a conductive layer, and the second layer of Cu—Ni—X film is formed as an oxidation-resistant protective film of the first layer.

  Hereinafter, the Cu laminated film will be described in detail.

  A film made of pure Cu or a Cu-based alloy is used as the first layer. Hereinafter, these films may be referred to as “Cu-based films”. When the first layer is formed as a conductive layer, the first layer is a Cu-based film and preferably has an electric resistivity of 10 μΩ · cm or less, more preferably 5 μΩ · cm or less. As the first layer Cu-based alloy film, a film containing at least one Z element selected from the group consisting of Ti, Mn, Fe, Co, Ni, Ge, and Zn, with the balance being Cu and inevitable impurities. Can be mentioned. By including the Z element, there are effects such as improvement of various corrosion resistances and adhesion to the substrate. These elements may be used alone or in combination of two or more. As shown in the examples described later, the oxidation resistance and wet etching processability desired in the present invention can be achieved by forming the prescribed second layer, and does not depend on the composition of the first layer. For example, the Z element may be contained in a total amount exceeding 0 atomic% and not exceeding 2 atomic%.

  The film thickness of the second layer is preferably 10 nm or more, more preferably 30 nm or more in order to ensure sufficient oxidation resistance. On the other hand, if the thickness of the second layer is too thick, although depending on the composition of the second layer, the etching rate during wet etching tends to be slower than that of the first layer, and as a result, the processed shape becomes eaves. It is difficult to obtain excellent wet etching processability. Therefore, the film thickness of the second layer is preferably 200 nm or less, and more preferably 100 nm or less.

  The film thickness of the first layer is preferably 20 nm or more, more preferably 50 nm or more from the viewpoint of obtaining a film having a uniform film thickness and components during film formation. On the other hand, from the viewpoint of ensuring productivity, the thickness of the first layer is preferably 500 nm or less, and more preferably 400 nm or less.

  The total film thickness of the first layer and the second layer is preferably 30 nm or more, and more preferably 50 nm or more. The total film thickness is preferably 600 nm or less, and more preferably 400 nm or less.

  The present invention also includes the Cu laminated film, that is, a laminated body having the first layer and the second layer on the substrate. The laminate may include other layers such as an adhesion layer. Hereinafter, the form of this laminate will be described with reference to patterns.

  FIG. 1 is a schematic cross-sectional view illustrating the configuration of the laminate of the invention. In FIG. 1, a film made of pure Cu or a Cu-based alloy as the first layer 1 is provided on the substrate 3, and a Cu—Ni—X film as the second layer 2 is provided on the top surface thereof. Layer 1 is protected. Examples of the substrate 3 include a glass substrate, a film substrate, a plastic substrate, a quartz substrate, and a silicon substrate.

  2 and 3 are schematic cross-sectional views showing modifications of the laminated body shown in FIG. The substrate 3, the first layer 1 and the second layer 2 in FIGS. 2 and 3 are the same as those in FIG. 1, and in each case, the second layer 2 protects the first layer 1, that is, the second layer 2 is the outermost surface. The structure is a layer.

  FIG. 2 shows a structure in which the adhesion layer 4 is provided between the substrate 3 and the first layer 1 in FIG. The adhesion layer 4 is not particularly limited as long as it is generally used, and examples thereof include a Ti film, a Mo film, a Ni film, a Cr film, and the like having a film thickness of 5 to 30 nm.

  FIG. 3 shows a structure in which the adhesion layer 4 is provided between the substrate 3 and the first layer 1 and between the first layer 1 and the second layer 2 in FIG. The adhesion layer 4 in FIG. 3 may be any generally used one, such as a Ti film, a Mo film, a Ni film, a Cr film, and the like, for example, having a film thickness of 5 to 30 nm. .

  The Cu—Ni—X film is preferably formed by a sputtering method. If the sputtering method is used, a Cu—Ni—X film having almost the same composition as the sputtering target can be formed. As the sputtering method, for example, any sputtering method such as a DC sputtering method, an RF sputtering method, a magnetron sputtering method, or a reactive sputtering method may be employed, and the formation conditions may be set as appropriate.

  For example, in order to form the Cu—Ni—X film by the sputtering method, the target is made of a Cu alloy containing a predetermined amount of the Ni or X element, and a desired Cu—Ni— If a Cu alloy sputtering target having the same composition as that of the X film is used, a Cu—Ni—X film having a desired component and composition can be formed without causing a composition shift. Alternatively, two or more pure metal targets or alloy targets having different compositions may be used, and these may be discharged simultaneously to form a film. Or you may form into a film, adjusting a component by carrying out chip-on of the metal of an alloy element to a pure Cu target.

In the case where a Cu—Ni—X film is formed by a sputtering method, the following conditions are given as an example of sputtering conditions.
Sputtering conditions Film forming method: Sputtering method Film forming apparatus: CS-200 manufactured by ULVAC
Substrate temperature: room temperature Deposition gas: Ar gas Gas pressure: 2 mTorr
Sputter power: 10-500W
Degree of vacuum: 1 × 10 ^-6 Torr or less

  The Cu alloy sputtering target of the present invention may have any shape depending on the shape and structure of the sputtering apparatus, such as a square plate shape, a circular plate shape, and a donut plate shape. As a method for producing the Cu alloy sputtering target, a method of producing an ingot made of a Cu-based alloy by a melt casting method, a powder sintering method, or a spray forming method, a preform made of a Cu-based alloy, that is, a final Examples thereof include a method obtained by producing an intermediate before obtaining a dense body and then densifying the preform by a densification means.

  As a method for forming each layer other than the Cu—Ni—X film, a method usually used in the technical field of the present invention can be appropriately employed.

  The laminate having the Cu—Ni—X film can be applied to a wiring electrode or an input device. The input device includes an input device having an input unit in a display device such as a touch panel, and an input device having no display device such as a touch pad. In particular, the Cu—Ni—X film of the present invention is preferably used for a touch panel sensor.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples, and is implemented with appropriate modifications within a range that can meet the purpose described above and below. Of course, any of these is also included in the technical scope of the present invention. That is, in the following, an etchant containing iron chloride is used as an etchant used for wet etching, but the present invention is not limited to this. An etchant containing ammonium persulfate, an etchant containing hydrogen peroxide, phosphoric acid, A mixed acid etching solution containing nitric acid and acetic acid can also be used.

(1) Preparation of Laminate Sample As a transparent substrate, an alkali-free glass plate having a diameter of 4 inches and a thickness of 0.7 mm was prepared, and on this alkali-free glass plate, a DC magnetron sputtering method was used. A laminated film of the first layer and the second layer shown in 4 was formed. Specifically, in Table 2, a laminated film including a pure Cu film as the first layer and a Cu—Ni—X film as the second layer was formed. In Table 3, various Cu-based alloy films were formed as the first layer, and a Cu—Ni—Al film containing Ni 6.4 atomic% and Al 29.3 atomic% was formed as the second layer. In Table 4, a pure Cu film is formed as the first layer, a Cu—Ni—Al film containing Ni 6.4 atomic% and Al 29.3 atomic% is formed as the second layer, and each film of the first layer and the second layer is formed. The thickness was changed. In addition, in order to measure the electrical resistivity of the first layer, a sample in which only the Cu-based film described in Table 1 was formed on the non-alkali glass plate was also prepared.

In film formation, the atmosphere in the chamber is once adjusted to an ultimate vacuum of 3 × 10 ⁻⁶ Torr before film formation, and then the first layer and second layer are formed on the substrate in the order of the following sputtering conditions. Sputtering was performed to form a Cu laminated film. As a sputtering target, a pure Cu sputtering target, or a target having the same composition as each Cu-Ni-X film or each Cu-based alloy film of the first layer, both of which are disk-type sputtering targets having a diameter of 4 inches Was used. The following evaluation was performed using the sample having the Cu laminated film.

Sputtering conditions Film forming method: Sputtering method Film forming apparatus: CS-200 manufactured by ULVAC
Substrate temperature: room temperature Deposition gas: Ar gas Gas pressure: 2 mTorr
Sputter power: 10-500W
Degree of vacuum: 1 × 10 ^-6 Torr or less

(2) Measurement of electric resistivity of first layer The electric resistivity of the first layer in the laminated film was measured as follows. That is, the electrical resistivity was measured by a four-terminal method using a sample in which only a Cu-based film described in Table 1 was formed on an alkali-free glass plate. The results are shown in Table 1. In this example, those having an electrical resistivity of 1.0 × 10 ⁻⁵ Ω · cm or less were accepted, and those having an electrical resistivity exceeding 1.0 × 10 ⁻⁵ Ω · cm were rejected. In Table 1, for example, No. “3.0E-06” of 1 means 3.0 × 10 ⁻⁶ . Hereinafter, the same applies to the display of the sheet resistance values in Tables 2 to 4.

As is apparent from Table 1, all of the films made of pure Cu or Cu-based alloy used as the first layer in this example had an electric resistivity of 1.0 × 10 ⁻⁵ Ω · cm or less.

(3) Measurement of reflectance change before and after heat treatment For the purpose of evaluating oxidation resistance, the reflectance change before and after heat treatment was measured as follows. That is, using the sample immediately after the film formation, the reflectance at a wavelength of 550 nm was measured with a spectrophotometer: V-570 manufactured by JASCO Corporation, and used as the reflectance before heat treatment. Subsequently, the sample which measured the reflectance before the said heat processing using the infrared lamp heating apparatus: RTP-6 by ULVAC company was heat-processed by heating at 150 degreeC for 1 hour in air | atmosphere. Using this heat-treated sample, the reflectance at a wavelength of 550 nm was measured in the same manner as described above to obtain the reflectance after heat treatment.

  A value obtained by subtracting the reflectance after the heat treatment from the reflectance before the heat treatment was defined as “amount of change in reflectance before and after the heat treatment”. The results are shown in Tables 2-4. In this example, a reflectance change amount of 15% or less before and after the heat treatment is regarded as acceptable as being excellent in oxidation resistance, and a reflectance change amount exceeding 15% is regarded as being inferior as being inferior in oxidation resistance. did.

(4) Measurement of eave width or side etching width at the time of wet etching processing For the purpose of evaluating wet etching processability, for the sample having the Cu laminated film, wiring processing is performed by the wet etching method as described below. The width of the eaves-like etching residue after the wiring processing was measured.

  Specifically, in the present example, etching was performed on the sample using an etching solution in which Pureetch F108 manufactured by Hayashi Junyaku Kogyo Co., Ltd. containing iron chloride was diluted 10 times with pure water. Subsequently, about the sample which performed the said etching process, the cross-sectional shape and planar shape were observed using the Hitachi Power Solutions company electron microscope: S-4000. In the cross-sectional shape, a portion where the second layer remains longer than the first layer was defined as “eave”, and a portion where the second layer was shorter than the first layer was determined as “side etching”. Further, in the planar shape, the eave width or the side etching width was calculated. At this time, the eave width was determined as a positive number and the side etching width was determined as a negative number. The results are shown in Tables 2-4.

  In this embodiment, the eave width is 5.0 μm or less, or the wiring shape is side-etched, that is, the value in “Elongation width or side etching width during wiring processing by wet etching method” in Tables 2 to 4 is a negative number. Some were accepted as being excellent in wet etching processability, and those having an eave width exceeding 5.0 μm were rejected as being inferior in wet etching processability.

(5) Measurement of sheet resistance of laminated film The sheet resistance of the laminated film was measured by the following method. That is, the sheet resistance was measured by a four-terminal method using the sample having the Cu laminated film. The results are shown in Tables 2-4. In this example, a sheet having a sheet resistance of 10Ω / □ or less was accepted as having a low sheet resistance, and a sheet having a sheet resistance exceeding 10Ω / □ was rejected as having a high sheet resistance. In Tables 2 to 4, in all examples, the sheet resistance of the laminated film was 10 Ω / □ or less. This is considered to be due to the use of a low electrical resistance Cu-based film as the first layer.

  Table 2 shows the following. No. 1, 8 and 13 are examples in which the second layer is made of Cu and Ni and does not contain the X element. In these examples, the eave width was increased and the wet etching processability was poor. No. 1 and No. No. 8 also resulted in inferior oxidation resistance.

  No. in Table 2 2-7 and no. 9 to 12 are examples of Cu—Ni—Al films in which the second layer contains Al as the Ni and X elements.

  Of these examples, no. No. 2 was inferior in oxidation resistance because the amount of Ni in the second layer was insufficient and the total amount of Ni and X elements was also insufficient. No. In Nos. 3 and 9, the second layer contains Al as the X element, but its content is insufficient. No. 3 was inferior in oxidation resistance because the total amount of Ni and X elements was insufficient. No. In No. 9, the width of the eaves was increased, resulting in poor wet etching processability. No. In No. 12, since the amount of Ni in the second layer was excessive, the eave width was increased, resulting in poor wet etching processability. On the other hand, No. Nos. 4 to 7, 10 and 11 are examples satisfying the requirements of the present invention, and it can be seen that excellent oxidation resistance and wet etching processability are exhibited.

  No. in Table 2 14 to 18 are examples of Cu—Ni—Mn films in which the second layer contains Mn as Ni and X elements.

  Of these examples, no. Nos. 14 and 15 were inferior in oxidation resistance because the second layer contained Mn as the X element, but its content was insufficient and the total amount of Ni and X elements was also insufficient. On the other hand, No. Nos. 16 to 18 are examples that satisfy the prescribed requirements in the present invention, and it is understood that excellent oxidation resistance and wet etching processability are exhibited.

  No. in Table 2 19 to 21 are examples of Cu—Ni—Sn films in which the second layer contains Sn as the Ni and X elements.

  Of these examples, no. No. 19 was inferior in oxidation resistance because the second layer contained Sn as the X element, but its content was insufficient. On the other hand, No. 20 and 21 are examples that satisfy the prescribed requirements in the present invention, and it can be seen that excellent oxidation resistance and wet etching processability are exhibited.

  In Table 3, the second layer is made constant with a Cu—Ni—Al film containing Ni 6.4 atomic% and Al 29.3 atomic%, and the first layer is composed of various Cu-based alloy films. The effect of the film on the properties of the laminated film was confirmed.

  From the results shown in Table 3, various Cu-based alloy films were used as the first layer. In either case, excellent oxidation resistance and wet etching processability were obtained. From these results, the oxidation resistance and wet etching processability of the laminated film are mainly due to the component composition of the second layer, which is an oxidation-resistant protective layer, and various Cu-based alloy films are used for the first layer. It can be seen that the characteristics do not change.

  In Table 4, the first layer is a pure Cu film, the second layer is a Cu-Ni-Al film containing Ni 6.4 atomic% and Al 29.3 atomic%, and the first and second layers are made constant. The thickness dependency of each layer was confirmed by changing the thickness. As a result, no. As shown in FIG. 1, when the film thickness of the second layer exceeded the recommended upper limit of 200 nm, the eave width during wet etching could not be sufficiently reduced, and good wet etching processability could not be obtained. In Table 4, No. As shown in FIG. 7, when the film thickness of the second layer was below the recommended lower limit of 10 nm, the amount of change in reflectance before and after the heat treatment was large, and sufficient oxidation resistance could not be ensured. In contrast, no. As shown in 2 to 6 and 8 to 11, in the example in which the film thickness of the second layer is within the recommended range, sufficiently excellent oxidation resistance and wet etching processability were obtained.

DESCRIPTION OF SYMBOLS 1 Film | membrane which consists of pure Cu or Cu base alloy which is 1st layer 2 Cu-Ni-X film | membrane 3 which is 2nd layer 3 Substrate 4 Adhesion layer

Claims (8)

The first layer has a film made of pure Cu or a Cu-based alloy, and the second layer has a Cu alloy film.
1 type X element selected from the group which consists of Al, Mn, and Sn is included, and Ni is 3.0 atomic% or more and 19.0 atomic% or less (however, when said X element is Sn, 12 atomic% And the remainder comprises Cu and inevitable impurities, and
When the X element is Al, the content of the X element is x atom% or more and 40 atom% or less obtained from the following formula (1), and the total amount of Ni and X element is 16.0 atom% or more. And
When the X element is Mn, the content of the X element is x atom% or more and 40 atom% or less obtained from the following formula (1), and the total amount of Ni and X element is 20.0 atom% or more. And
When the X element is Sn, the content of the X element is x atom% or more and 30 atom% or less obtained from the following formula (1), and the total amount of Ni and X element is 16.0 atom% or more. Cu laminated film characterized by being.
x = 1.96 × Ni + 1.64 (1)
In the above formula (1), Ni indicates the Ni content in atomic% in the Cu alloy film.   The Cu laminated film according to claim 1, wherein the second layer has a thickness of 10 nm to 200 nm.   The Cu-based alloy in the first layer contains at least one Z element selected from the group consisting of Ti, Mn, Fe, Co, Ni, Ge, and Zn, and the balance is made of Cu and inevitable impurities. The Cu laminated film according to 1 or 2.   The laminated body which has Cu laminated film in any one of Claims 1-3 on a board | substrate.   The wiring electrode using the laminated body of Claim 4.   An input device using the laminate according to claim 4.   A touch panel sensor using the laminate according to claim 4. Cu alloy sputtering target for forming the Cu alloy film according to claim 1.