KR101553472B1

KR101553472B1 - Laminated wiring film for electronic components and sputtering target material for forming coating layer

Info

Publication number: KR101553472B1
Application number: KR1020140032109A
Authority: KR
Inventors: 히데오 무라타
Original assignee: 히타치 긴조쿠 가부시키가이샤
Priority date: 2013-03-22
Filing date: 2014-03-19
Publication date: 2015-09-15
Also published as: TW201437405A; TWI498441B; CN104064549A; CN104064549B; KR20140116002A; JP2014208887A; JP6361957B2

Abstract

A laminated wiring film for an electronic part using a coating layer containing an Mo alloy which can improve a moisture resistance and oxidation resistance and can maintain a low electric resistance value even after a heating step when laminated with Al as a main conductive layer of low resistance And a sputtering target material for forming a coating layer.
A laminated wiring film for electronic parts comprising a metal film formed on a substrate, the laminated wiring film comprising a main conductive layer containing Al as a main component and a coating layer covering at least one of the main conductive layer, wherein the coating layer has a composition formula of Mo ₁₀₀ _-xy -Ni _x -Nb _y, 10≤x≤30, 3≤y≤15 appears as, the balance being unavoidable impurities in the composition formula of the electronic components and the multilayer wiring film for the ratio Mo source ₁₀₀ including a _-xy -Ni _x - Nb _y , 10? X? 30, and 3? _Y ? 15, and the remaining amount includes inevitable impurities.

Description

TECHNICAL FIELD [0001] The present invention relates to a laminated wiring film for electronic parts and a sputtering target material for forming a covering layer.

The present invention relates to a sputtering target material for forming a coating layer for forming a laminated wiring film for electronic parts requiring moisture resistance and oxidation resistance and a coating layer covering all the main layers of the laminated wiring film for electronic parts.

(Flat panel display, hereinafter referred to as "FPD") such as a liquid crystal display (hereinafter referred to as "LCD"), a plasma display panel (hereinafter referred to as "PDP" ), Thin film electronic components such as various semiconductor devices, thin film sensors, and magnetic heads, it is necessary to form a low resistance wiring film. For example, FPDs such as LCDs, PDPs, organic EL displays and the like for fabricating thin film devices on glass substrates are required to have low resistances in their wiring films due to large screen, high precision, and high speed response. Recently, new products such as a flexible FPD using a touch panel or a resin substrate that adds operability to the FPD have been developed.

In recent years, the Si semiconductor film is the main stream in the thin film transistor (hereinafter referred to as " TFT ") used as the driving element of the FPD, and the Al film in the low resistance wiring film is in contact with Si, So that the characteristics of the TFT may deteriorate. As a result, a laminated wiring film having a barrier film made of pure Mo or a Mo alloy having excellent heat resistance is used between Al and Si.

In addition, indium-tin oxide (hereinafter referred to as " ITO "), which is a transparent conductive film, is generally used for a pixel electrode extending from a TFT or a position detection electrode of a touch panel used for a portable terminal or a tablet PC. Also in this case, if Al, which is a wiring film, is in contact with ITO, an oxide is generated at the interface, and electrical contact properties may deteriorate. As a result, a pure Mo or Mo alloy is formed as a contact film between Al and ITO to ensure contact properties with ITO.

As described above, in order to obtain a wiring film taking advantage of the low resistance property of Al, a pure Mo or Mo alloy film is indispensable, and a laminated wiring film in which Al is coated with pure Mo or a Mo alloy is required.

In recent years, transparent semiconductor films using oxides that are thought to be suitable for high-speed driving have been actively studied more than amorphous Si semiconductors. In the coating films used as the contact films and barrier films of the laminated films of these oxide semiconductors and Al, Is being studied.

Therefore, the Applicant has proposed a Mo alloy film which is excellent in corrosion resistance, heat resistance and adhesion to a substrate, and has a low resistance and contains 3 to 50 atomic% of V or Nb added thereto as means for improving the properties of pure Mo (See, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2002-190212

The Mo-V and Mo-Nb alloys proposed in the above-mentioned Patent Document 1 are widely used for FPDs formed on a glass substrate because they have better corrosion resistance, heat resistance and adhesiveness to substrates than Mo.

However, in the case of manufacturing an FPD, after forming a laminated wiring film on a substrate, it may be left in the atmosphere for a long time when moving to the next step. Further, in order to improve the convenience, in a lightweight and flexible FPD using a resin film, since the resin film has moisture permeability as compared with conventional glass substrates and the like, higher moisture resistance is required for the laminated wiring film.

Further, when the signal line cable is attached to the terminal portion of the FPD or the like, the laminated wiring film is also required to be improved in oxidation resistance because it may be heated in the atmosphere. Further, in the case of a semiconductor film using an oxide, a heat treatment at a high temperature of 350 DEG C or higher may be carried out after forming an oxygen-containing atmosphere or a protective film containing oxygen, in order to improve or stabilize the characteristics. For this reason, there is an increasing demand for improvement in oxidation resistance in the laminated wiring film so that stable characteristics can be maintained even after these heating processes.

According to the study by the present inventors, it has been found that Mo-V, Mo-Nb alloy and pure Mo described above are insufficient in moisture resistance and oxidation resistance in the above-mentioned environment, and when the coating layer of the laminated wiring film is used in the manufacturing process of FPD, It is confirmed that there is a case where the surface is oxidized and discolored. If the oxidation resistance is insufficient, the electrical contact property is deteriorated and the reliability of the electronic parts is deteriorated.

In addition, the heating temperature during the TFT manufacturing process tends to increase for high-speed driving. When the heating process is performed at a higher temperature, the problem that the alloy element contained in the laminated wiring film diffuses into Al and the electric resistance value increases Respectively.

It is an object of the present invention to provide an electronic device using a coating layer containing a Mo alloy which can maintain a low electric resistance value even after a heating process when the moisture resistance and oxidation resistance are improved, A laminated wiring film for a component and a sputtering target material for forming the coating layer.

In view of the above problems, the present inventors have responded to the optimization of elements newly added to Mo. As a result, it has been found that by adding a specific amount of Ni and Nb in combination with Mo, moisture resistance and oxidation resistance can be improved, and a low electric resistance value can be maintained even when a coating layer of Al, And reached the present invention.

That is, the present invention provides a laminated wiring film for electronic parts having a metal film formed on a substrate, the laminated wiring film comprising a main conductive layer containing Al as a main component and a coating layer covering at least one surface of the main conductive layer, Is Mo ₁₀₀ _-xy- Ni- _X- Nb _y , 10? _X ? 30, and 3? _Y ? 15, and the remaining amount includes inevitable impurities.

In the present invention, it is preferable that x and y in the composition formula are 10? X? 20, 5? Y? 10, and x / y is 1 or more.

The coating layer is preferably a ground layer.

It is preferable that the coating layer is a cap layer. In the present invention, the term " cap layer " refers to a coating layer provided on the opposite side of the substrate with the main conductive layer sandwiched therebetween.

It is more preferable that the coating layer is a base layer and a cap layer. In the present invention, " base layer " means a covering layer provided between the main conductive layer and the substrate.

Further, the present invention is a sputtering target material for forming a coating layer for forming the coating layer, wherein the composition formula in the atomic ratio is Mo ₁₀₀ _-xy- Ni _x -T _y , 10? _X? 30, And the remaining amount is inevitable impurities.

In the present invention, it is preferable that x and y in the above composition formula are 10? X? 20, 5? Y? 10 and x / y is 1 or more.

The laminated wiring film for electronic parts of the present invention can improve moisture resistance and oxidation resistance. In addition, even in the heating step when the main conductive layer is laminated with Al, it is possible to suppress the increase of the electric resistance value and to maintain a low electric resistance value. Thereby, it has an advantage that it can contribute to the stable manufacturing and reliability improvement of electronic parts by using it for various electronic parts, for example, a wiring film such as an FPD formed on a resin substrate. do. Particularly, it becomes a multilayer wiring film which is very useful for a flexible FPD using a touch panel or a resin substrate.

1 is an example of a cross-sectional view of a laminated wiring film for electronic parts of the present invention.

Fig. 1 shows an example of a cross-sectional view of a laminated wiring film for electronic parts of the present invention. The laminated wiring film for electronic parts of the present invention includes a covering layer covering at least one surface of the main conductive layer 3 containing Al as a main component, and is formed on the substrate 1, for example. 1, coating layers 2 and 4 are formed on both sides of the main conductive layer 3 and may be formed only on either the base layer 2 or the cap layer 4 and may be appropriately selected. When only one side of the main conductive layer is covered with the coating layer of the present invention, the other side of the main conductive layer may be covered with a coating layer having a composition different from that of the present invention, depending on the use of the electronic component.

An important feature of the present invention is that, in the coating layer of the multilayer wiring film for electronic parts shown in Fig. 1, a specific amount of Ni and Nb are added to Mo to improve Moisture resistance and oxidation resistance, The present inventors found a new Mo alloy capable of maintaining a low electric resistance even after the heating process. Hereinafter, the wiring film for electronic parts of the present invention will be described in detail.

In the following description, " moisture resistance " means that the electrical resistance value of the wiring film under the high temperature and high humidity environment is difficult to change and the electrical contact property is hard to deteriorate. The moisture resistance can be confirmed by discoloration of the wiring film, Can be evaluated quantitatively. The " oxidation resistance " means difficulty in deteriorating the electrical contact property under a high temperature environment, and can be confirmed by discoloration of the wiring film, and can be quantitatively evaluated by, for example, reflectance.

The reason why Ni is added to the Mo alloy forming the coating layer of the multilayer wiring film for electronic parts of the present invention is mainly for the purpose of improving the oxidation resistance of the coating layer. When pure Mo is heated in the atmosphere, it is oxidized to discolor the surface of the film and the electrical contact property is deteriorated. The coating layer of the multilayer wiring film for electronic parts of the present invention has an effect of suppressing discoloration of the coating layer by adding a specific amount of Ni to Mo and can improve oxidation resistance. The effect becomes remarkable when the addition amount of Ni is 10 atomic% or more.

On the other hand, Ni is an element easily diffused to Al, and the mutual diffusion coefficient of Ni in Al is larger than the mutual diffusion coefficient of Mo in Al. If the amount of Ni added to Mo exceeds 30 atomic%, Ni contained in the coating layer is diffused into Al of the entire primary layer in the heating process for producing electronic parts such as FPD, It gets harder. Therefore, the addition amount of Ni is 10 to 30 atomic%.

In addition, when a coating layer is formed on the surface of the main conductive layer and heated to a temperature higher than 350 占 폚, Ni of the coating layer is likely to diffuse into Al of the entire main conductive layer and the electric resistance value may rise. In order to maintain a low electric resistance value in the present invention, it is preferable that the addition amount of Ni is 20 atomic% or less.

The reason why Nb is added to the Mo alloy forming the coating layer of the multilayer wiring film for electronic parts of the present invention is mainly to improve moisture resistance of the coating layer. Nb is a metal having a property of being easily bonded to oxygen or nitrogen, and has an effect of protecting the inside of the wiring film by forming a passivation film on the surface in a high temperature and high humidity atmosphere. The effect is further enhanced by adding Nb in combination with Ni described above, rather than by adding Nb alone. The coating layer of the multilayer wiring film for electronic parts of the present invention can remarkably improve the moisture resistance by adding a specific amount of Nb to Mo. This effect becomes clear that the addition amount of Nb is 3 atomic% or more, and becomes remarkable at 5 atomic% or more.

On the other hand, if the addition amount of Nb is more than 15 atomic%, the corrosion resistance is excessively improved and the etching rate in the etchant for Al is lowered. As a result, residues are generated at the time of etching the laminated film of Al , Etching can not be performed. For this reason, in the present invention, the addition amount of Nb is 3 to 15 atomic%.

In addition, in order to easily achieve the moisture resistance and the etching property in the laminated film of Al, it is preferable that the addition amount of Nb is 5 to 10 atomic%.

The atomic ratio (x / y) of Ni and Nb combinedly added to the Mo alloy forming the coating layer is preferably 1 or more. As described above, Nb is an element involved in moisture resistance improvement. When added too much, oxidation resistance lowers. When the addition amount of Nb is larger than the addition amount of Ni, it becomes difficult to obtain an effect of improving oxidation resistance. Therefore, by adding Ni and Nb so that the atomic ratio (x / y) of Ni and Nb becomes 1 or more, moisture resistance and oxidation resistance of the coating layer can be obtained more stably.

When the heating temperature in the production process of the laminated wiring film is higher than 350 DEG C, it is more preferable that the total amount of Ni and Nb combinedly added to the Mo alloy forming the coating layer is 35 atomic% or less. The reason for this is that not only Ni but also Nb is an element that thermally diffuses into Al. When the sum of Ni and Nb exceeds 35 at%, Ni or Nb of the coating layer diffuses into Al of the entire primary layer, .

In the laminated wiring film for electronic parts of the present invention, in order to stably obtain low electric resistance, moisture resistance and oxidation resistance, it is preferable that the thickness of the main conductive layer is 100 to 1000 nm. If the film thickness of the main conductive layer is thinner than 100 nm, the electric resistance value tends to increase due to the influence of scattering of electrons peculiar to the thin film. On the other hand, if the film thickness of the entire pre-charge layer is thicker than 1000 nm, it takes time to form a film or warpage of the substrate tends to occur due to film stress. A more preferable range of the film thickness of the main conductive layer is 200 to 500 nm.

Further, as the main conductive layer containing Al as a main component, pure Al which can obtain the lowest electric resistance value is suitable. In consideration of reliability such as heat resistance and corrosion resistance, an Al alloy to which a transition metal or a semi-metal is added to Al may be used. At this time, the addition amount of the element to be added to Al is preferably 5 atomic% or less so that the electrical resistance value as low as possible is obtained.

In addition, in the laminated wiring film for electronic parts of the present invention, it is preferable that the thickness of the coating layer is 20 to 100 nm in order to stably obtain a low electric resistance value, moisture resistance and oxidation resistance. When the thickness of the coating layer is less than 20 nm, the continuity of the Mo alloy film is lowered, and moisture resistance and oxidation resistance may not be sufficiently obtained.

On the other hand, if the thickness of the coating layer exceeds 100 nm, the electrical resistance value of the coating layer becomes high, and when laminated with the Al film of the main conductive layer, it becomes difficult to obtain a low electric resistance value as the electronic component laminate wiring film. Further, in the present invention, in order to suppress the diffusion of atoms to Al forming the main conductive layer at the time of heating, the coating thickness of the coating layer is more preferably 20 to 70 nm.

In order to form each layer of the multilayer wiring film for electronic parts of the present invention, a sputtering method using a sputtering target is optimum. When forming the coating layer, for example, a method of forming a film by using an Mo alloy sputtering target having the same composition as the composition of the coating layer, a method of forming a film by co-sputtering using an Mo-Ni alloy sputtering target and an Mo- Etc. can be applied. It is more preferable to form the sputtering target by using the Mo alloy sputtering target having the same composition as that of the coating layer in terms of simplicity of setting of the sputtering and easy obtaining of the coating layer of the desired composition.

Therefore, in order to form the coating layer of the multilayer wiring film for electronic parts of the present invention, the composition formula in the atomic ratio is represented by Mo ₁₀₀ _-xy- Ni- _X- Nb _y , 10? _X ? 30, By using a sputtering target containing inevitable impurities, a coating layer can be stably formed.

As described above, in order to obtain a multilayer interconnection film for electronic parts having a low electric resistance value even when subjected to a high-temperature heating process at 350 占 폚 as described above, it is necessary to add 10 to 20 atom% of Ni and 5 to 10 atom% , And the atomic ratio (x / y) of Ni and Nb is preferably 1 or more.

As a method for producing the sputtering target material for forming a coating layer of the present invention, for example, a powder sintering method is applicable. As the powder sintering method, it is possible to use, for example, a raw powder by preparing an alloy powder by the gas atomization method, or a mixed powder obtained by mixing a plurality of alloy powder or pure metal powder so as to have the final composition of the present invention Do. As the sintering method of the raw material powder, it is possible to use pressure sintering such as hot isostatic pressing, hot press, discharge plasma sintering, extrusion press sintering and the like.

In the Mo alloy forming the coating layer of the multilayer wiring film for electronic parts of the present invention, the content of inevitable impurities other than Mo, which occupies a remaining portion other than Ni and Nb, which are essential elements for ensuring oxidation resistance and moisture resistance, is preferably small But may include inevitable impurities such as oxygen, nitrogen or carbon, transition metals Fe, Cu, semimetal Al, Si, etc., insofar as the effect of the present invention is not impaired. For example, oxygen and nitrogen of the gas components are respectively not more than 1000 mass ppm, carbon is not more than 200 mass ppm, Fe, Cu is not more than 200 mass ppm, Al and Si are not more than 100 mass ppm, It is preferably 99.9 mass% or more.

[Example 1]

First, a sputtering target material for forming an Mo alloy film to be a coating layer was prepared. Mo powder having an average particle diameter of 6 占 퐉, Ni powder having an average particle diameter of 100 占 퐉 and Nb powder having an average particle diameter of 85 占 퐉 were mixed so as to have the composition shown in Table 1, filled in a can made of softened steel, To remove gas components in the can and then sealed. Subsequently, the sealed can was placed in a hot isostatic pressing apparatus and sintered under the conditions of 800 ° C and 120 MPa for 5 hours, and then machined to produce a sputtering target material having a diameter of 100 mm and a thickness of 5 mm. In addition, sputtering target materials of pure Mo, Mo-Nb alloy, and Mo-Ni alloy to be compared were similarly manufactured.

Each of the sputtering target materials obtained above was soldered to a backing plate made of copper and mounted on a sputtering apparatus. As the sputtering apparatus, SPF-440H manufactured by CANON ANERVA KABUSHIKI KAISHA was used.

A laminated wiring film for an electronic component was obtained by forming the underlying layer / main conductive layer / cap layer shown in Fig. 1 in this order on a glass substrate having a size of 25 mm x 50 mm by sputtering in the film thickness configuration shown in Table 1, respectively. For comparison, pure Mo, a Mo-Nb alloy film, and an Mo-Ni alloy film were laminated with an Al film, respectively, to produce a laminated wiring film.

To evaluate the oxidation resistance, changes in reflectance after heating at 200 ° C, 250 ° C, 300 ° C, and 350 ° C for 1 hour in the atmosphere were measured. The evaluation of the moisture resistance was carried out by measuring the change in the reflectance when the sample was allowed to stand for 100 hours, 200 hours and 300 hours in a high-temperature and high-humidity atmosphere of 85 占 폚 占 85%. For the measurement of the reflectance, the reflection characteristic of the visible light region was measured using a spectroscopic colorimeter CM-2500d manufactured by Konica Minolta Co., Ltd. The results are shown in Table 1.

As shown in Table 1, the reflectance of the laminated wiring film is lowered when it is heated in the atmosphere, and it tends to lower even if it is left in a high temperature and high humidity atmosphere. The reflectance of the multilayer wiring film using the pure Mo as the coating layer of the comparative example is lowered at 250 ° C under atmospheric heating and significantly lowered at 350 ° C and is lowered in oxidation resistance and left in the high temperature and high humidity atmosphere for 100 hours, .

The reflectance of the laminated wiring film of sample No. 2 as a comparative example using Mo-10 atomic% Nb in the coating layer was remarkably lowered at 300 캜 when heated in air and it was confirmed that the oxidation resistance was low. The evaluation was stopped.

The reflectance of the laminated wiring films of samples Nos. 3 to 5, which are comparative examples using a Mo-Ni alloy as a coating layer, is low in the reflectance at the time of heating in air, but the reflectance Was found to decrease with an increase in the holding time. In addition, the reflectance of the laminated wiring film of Sample No. 12, which is a comparative example using a Mo-Ni-Nb alloy to which Ni and Nb are added, deviates from the present invention in the coating layer decreases with the rise in temperature Respectively.

The reflectance of the laminated wiring film of the sample No. 13 as a comparative example using the Mo-Ni-Nb alloy to which Ni and Nb were added to the coating layer deviating from the present invention decreased as the heating and holding time in the high temperature and the high humidity increased .

On the other hand, the reflectance of the laminated wiring film of the present invention, in which a Mo-Ni-Nb alloy containing Mo and Ni in a predetermined amount was added to Mo as a coating layer in the coating layer, is lowered even when left in an atmospheric heating atmosphere and a high- It was confirmed that the oxidation resistance can be greatly improved.

The improvement effect was remarkable by adding at least 10 atomic% of Ni and at least 5 atomic% of Nb, and it was confirmed that it is a laminated wiring film suitable for electronic parts.

[Example 2]

Subsequently, a change in the electrical resistance value when a part of the laminated wiring films fabricated in Example 1 was heat-treated in vacuum was confirmed. The electrical resistance value was measured using a 4-terminal thin film resistivity meter MCP-T400 manufactured by Kabushiki Kaisha Diana Instruments. The heating temperature was 250 DEG C, 300 DEG C, 350 DEG C, 400 DEG C and 450 DEG C for 1 hour. The measurement results are shown in Table 2.

As shown in Table 2, it was confirmed that when the Ni addition amount of the coating layer exceeded 30 atomic% deviating from the range of the present invention, the electric resistance value at the time of heating at 450 ° C was greatly increased.

On the other hand, it was confirmed that the increase in the electric resistance value was suppressed even when the laminated wiring film using the coating layer containing Ni and Nb in a specific amount added to Mo of the present invention was heated to 450 占 폚.

[Example 3]

Then, the etching property was evaluated. The photoresist was applied to only a half of the area of the substrate on which the laminated wiring film used in Example 2 was formed, dried, and immersed in an etchant for Al produced by Kanto Chemical Co., Ltd. to etch the uncoated portion. Thereafter, the substrate was cleaned with pure water, dried, and the vicinity of the boundary between the dissolving portion and the unmelted portion coated with the resist was observed with an optical microscope. The results are shown in Table 2.

In the laminated wiring film using the pure Mo or Mo-Ni alloy film for the coating layer of the comparative example, it was confirmed that the film in the vicinity of the boundary line was lifted and the end was peeled off. It is considered that the Mo alloy film of the coating layer between Al and the glass substrate is etched.

Sample No. 12 in which the addition amount of Nb was more than 15 atomic% could not be etched.

On the other hand, Sample No. 11 in which the addition amount of Nb was 15 atomic% in the present invention was found to have a little residue on the substrate, but etching was possible. As a result, it was confirmed that the addition amount of Nb greatly affects the etching property.

Further, it was confirmed that the laminated wiring film using Mo-Ni-Nb alloy in which Mo and Ni were added to the coating layer of the present invention by a predetermined amount of Ni and Nb had no film peeling occurring in the comparative example, and was able to be etched and excellent in etching property .

As described above, in order to simultaneously satisfy the oxidation resistance, the moisture resistance, the suppression of the increase of the electric resistance value during heating, and the etching property, the addition amount of Ni to be added to the coating layer is preferably 10 to 30 atomic%, the addition amount of Nb is 3 to 15 By atomic%.

[Example 4]

A PET (polyethylene terephthalate) film having an ITO film of 0.25 mm in thickness cut into a size of 25 mm x 50 mm was formed by the same method as in Example 1 using the sputtering method A laminated wiring film was formed, and humidity resistance was evaluated. As the evaluation of the moisture resistance, the change of the reflectance when the sample was allowed to stand for 50 hours, 150 hours, and 300 hours in a high temperature and high humidity atmosphere of 85 캜 85% was measured. The results are shown in Table 3.

It was confirmed that the laminated wiring film using a coating layer obtained by adding a specific amount of Ni and Nb to the Mo of the present invention showed the least decrease in reflectivity and was excellent in moisture resistance.

As described above, in order to satisfy the oxidation resistance, the moisture resistance, the suppression of an increase in electric resistance value during heating, and the etching property, it is preferable that the addition amount of Ni is 10 to 30 atomic% and the addition amount of Nb is 3 to 15 atomic% It was confirmed that it is preferable. Further, it was confirmed that it is more preferable to set the Ni content to 10 to 20 atomic% and the Nb content to 5 to 10 atomic% in order to suppress the increase of the electric resistance value at a high temperature and ensure high moisture resistance.

1: substrate
2: Coating layer (base layer)
3: Leading layer
4: Coating layer (cap layer)

Claims

A laminated wiring film for electronic parts comprising a substrate and a metal film formed on the substrate, the laminated wiring film comprising a main layer containing Al as a main component and a coating layer covering at least one of the main conductive layer, wherein the coating layer has a composition formula of Mo _100-xy -Ni _x -Nb _y , 10? _X ? 30, and 5? _Y ? 15, and the remaining amount includes inevitable impurities.

The method according to claim 1,
X and y in the composition formula are 10? X? 20 and 5? Y? 10, respectively, and x / y is 1 or more.

3. The method according to claim 1 or 2,
Wherein the coating layer is a ground layer positioned between the main conductive layer and the substrate.

3. The method according to claim 1 or 2,
Wherein the coating layer is a cap layer covering a surface of the surface of the main conductive layer opposite to the substrate.

3. The method according to claim 1 or 2,
Characterized in that the main conductive layer is covered with both a ground layer positioned between the main conductive layer and the substrate and a cap layer covering a surface of the main conductive layer opposite to the substrate, membrane.

A sputtering target material for forming a coating layer for forming a coating layer according to claim 1, wherein a composition formula in the atomic ratio is Mo _100-xy -Ni _x -Nb _y , 10? _X? 30, 5? _Y? 15, Characterized in that the sputtering target material contains an inevitable impurity.

The method according to claim 6,
X and y in the above composition formula are 10? X? 20 and 5? Y? 10, respectively, and x / y is 1 or more.