TWI547575B - Metal thin film and sputtering target material of molybdenum alloy for forming metal thin film - Google Patents

Description

Molybdenum alloy sputtering target for forming metal film and metal film

The present invention relates to a metal thin film used for an electronic component requiring moisture resistance and oxidation resistance, and a molybdenum alloy sputtering target for forming the metal thin film.

A liquid crystal display (hereinafter referred to as LCD), a plasma display panel (hereinafter referred to as PDP), and an electrophoresis for electronic paper, etc., which form a thin film device on a glass substrate. In addition to a flat panel display device (Flat Panel Display, hereinafter referred to as FPD), a low-resistance wiring film is required for thin-film electronic components such as various semiconductor devices, thin film sensors, and magnetic heads. For example, in the case of large screens, high definition, and high-speed response of FPDs such as LCDs, PDPs, and organic electroluminescence (EL) displays, the wiring film is required to have a low resistance. In addition, in recent years, novel products such as a touch panel that adds operability to FPD and a soft FPD that uses a resin substrate have been developed.

In recent years, a wiring film of a thin film transistor (TFT) used as a driving element of an FPD has a Si semiconductor film. When Al as a main wiring film is in direct contact with Si, there is thermal diffusion due to a heating step in the process of manufacturing a TFT, resulting in a change in characteristics of the TFT. Poor situation. Therefore, a laminated wiring film in which a metal thin film such as pure molybdenum or a molybdenum alloy having excellent heat resistance is formed between Al and Si as a barrier film is used.

In addition, a position detecting electrode connected to a pixel electrode of a TFT or a touch panel used in a portable terminal or a tablet computer (Personal Computer, PC) or the like generally uses indium tin oxide (hereinafter referred to as ITO) as a transparent conductive film. . In this case, when Al which is a main wiring film is in contact with ITO, an oxide is formed at the interface, and electrical contact property may deteriorate. Therefore, it is necessary to form a metal thin film such as pure molybdenum or a molybdenum alloy between Al and ITO of the wiring film to ensure contact with ITO.

In addition, the industry is conducting research on transparent semiconductor films using oxides that can drive higher speeds based on the amorphous Si semiconductors to date, and it is also studied to use Al and pure molybdenum or molybdenum for laminated films of such oxide semiconductors. A laminated wiring film such as an alloy.

Therefore, as a method of improving the characteristics of pure molybdenum, the present applicant has proposed a molybdenum alloy film in which 3 atom% to 50 atom% of V or Nb is added to Mo, and the molybdenum alloy film has corrosion resistance, heat resistance and The substrate is excellent in adhesion and low in electrical resistance (see, for example, Patent Document 1).

In addition, in recent years, a wiring film of a thin film transistor (TFT) used as a driving element of an FPD needs to have a low resistance, and the industry is investigating the use of Cu having a lower electric resistance than Al for a main wiring film. In addition, the touch panel substrate screen which is directly operability is displayed in the direction of the increase in the size of the FPD screen, and the industry is promoting the use of Cu for the main wiring material for the purpose of reducing the resistance.

As described above, in the case where the TFT is a Si semiconductor, if Cu which is a main wiring film directly contacts Si as in the case of Al, it is thermally diffused by the heating step in the process of manufacturing the TFT, and the characteristics of the TFT are deteriorated. Therefore, use between Cu and Si A metal thin film such as pure molybdenum or a molybdenum alloy which is excellent in heat resistance is used as a laminated wiring film of a barrier film.

Further, ITO (Indium Tin Oxide) which is a transparent conductive film is generally used as a position detecting electrode of a pixel electrode connected to a TFT or a touch panel used for a portable terminal or a tablet PC. Although the contact property with ITO is obtained by Cu, it is necessary to use a laminated wiring film in which Cu is covered with a metal thin film such as pure molybdenum or a molybdenum alloy in order to ensure adhesion.

In addition, the industry has applied research on transparent semiconductor films using oxides that can achieve higher-speed response based on the amorphous Si semiconductors of the past, and has also studied Cu and pure molybdenum or molybdenum on the wiring films of these oxide semiconductors. A laminated wiring film of a metal thin film of an alloy.

The present applicant has proposed to maintain a low resistance value of Cu or Ag by laminating Cu or Ag having low adhesion to glass or the like and a molybdenum alloy containing Mo and/or Nb as main components, and Corrosion resistance, heat resistance, and adhesion to a substrate are improved (for example, refer to Patent Document 2).

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2002-190212

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2004-140319

The Mo-V, Mo-Nb alloy and the like proposed in Patent Document 1 are superior to pure molybdenum in corrosion resistance, heat resistance, and adhesion to a substrate, and thus are widely used for FPD applications formed on a glass substrate.

However, in the case of manufacturing an FPD, a laminated wiring film may be formed on a substrate and then left in the atmosphere for a long time when it is moved to the next step. In addition, for the sake of A lightweight and soft FPD or the like which uses a resin film to improve the convenience, and the resin film is more hygroscopic than the conventional glass substrate or the like, so that the metal film is required to have higher moisture resistance.

Further, since the signal cable is attached to the terminal portion of the FPD or the like and heated in the air, it is required to improve the oxidation resistance of the metal thin film. Further, in order to improve the characteristics or stabilize the semiconductor film using an oxide, heat treatment at a high temperature of 350 ° C or higher may be performed in an atmosphere containing oxygen or after forming a protective film containing oxygen. Therefore, the demand for improving the oxidation resistance is increasing, so that the laminated wiring film using the metal thin film as the cover film on the main wiring film can maintain stable characteristics after the heat treatment.

According to the study of the present inventors, it has been confirmed that the above-mentioned Mo-V, Mo-Nb alloy or the like or pure molybdenum metal film is insufficient in moisture resistance or oxidation resistance in the above environment, and sometimes occurs in the manufacturing process of the FPD. The problem of discoloration occurs.

Further, according to the study of the present inventors, since the adhesion, moisture resistance, and oxidation resistance of Cu are much inferior to those of Al, a base film for ensuring adhesion to a substrate or a cover film for protecting a Cu surface is formed. The case of the metal film. In the case where the above Mo-V, Mo-Nb alloy or the like or pure molybdenum is used, moisture resistance or oxidation resistance is insufficient, and there is a problem in that a Cu film is formed in the FPD manufacturing step. Discoloration and oxygen permeation cause a large increase in Cu resistance. The discoloration of the cover film deteriorates the electrical contact property, resulting in a decrease in the reliability of the electronic component.

In addition, it has been confirmed that the heating temperature in the TFT manufacturing step tends to increase in order to achieve a large screen or high-speed driving of the FPD, and if it is subjected to a higher temperature heating step, it is contained in the metal film as a cover film. The alloying elements are thermally diffused into the main wiring film of Al or Cu, resulting in an increase in the resistance value.

An object of the present invention is to provide a metal thin film for an electronic component including a molybdenum alloy and a molybdenum alloy sputtering target for forming the metal thin film, which can improve moisture resistance or oxidation resistance, and low resistance Al When a metal thin film is formed as a base film or a cover film on the main wiring film of Cu, the low resistance value can be maintained even after the heating step.

In view of the above problems, the inventors of the present invention have made an effort to study the optimization of elements newly added to Mo. As a result, it has been found that moisture resistance and oxidation resistance are improved by compounding a specific amount of Ni with a specific amount of an element selected from the element group A of Cr, Zr, and Ta in Mo. Further, it has been found that when a metal thin film is used as a base film or a cover film of a low-resistance Al or Cu main wiring film, the low resistance value can be maintained even after a high-temperature heating step, thereby completing the present invention.

In other words, the present invention is a metal thin film containing at least one atomic group A selected from the group consisting of Cr, Zr and Ta in an amount of 3 atom% or more, containing 10 atom% to 45 atom% of Ni, and a total of 50 atom%. The following elements selected from the above element group A and the above Ni, and the remainder include Mo and unavoidable impurities.

When the element selected from the element group A is Cr and/or Zr, the total amount thereof is preferably from 3 atom% to 20 atom%.

In the case where the element selected from the above element group A is Ta, it is preferably added in an amount of from 3 atom% to 15 atom%.

Further, the present invention is a molybdenum alloy sputtering target for forming a metal thin film, which contains at least one atomic group A selected from the group consisting of Cr, Zr and Ta in an amount of 3 atom% or more, and contains 10 atom% to 45 atom%. Ni, and the total contains 50 atoms The element selected from the above element group A and below is less than % Ni, and the remainder contains Mo and unavoidable impurities.

When the element selected from the element group A is Cr and/or Zr, the total amount thereof is preferably from 3 atom% to 20 atom%.

In the case where the element selected from the above element group A is Ta, it is preferably added in an amount of from 3 atom% to 15 atom%.

The metal thin film of the present invention is superior in moisture resistance and oxidation resistance as compared with the prior metal thin film. Further, even in the heating step in the case where the Al or Cu of the main wiring film is laminated, the increase in the resistance value can be suppressed, and the low resistance value can be maintained. Thereby, by using various base parts, for example, a base film or a cover film formed on a resin substrate, it is advantageous in that it can contribute to stable manufacture of electronic parts or improvement in reliability, and is an manufacture of electronic parts. Useful technology. In particular, it is a metal thin film which is useful for a touch panel or a soft FPD using a resin substrate. The reason for this is that moisture resistance and oxidation resistance are particularly important for such products.

1‧‧‧Substrate

2‧‧‧Metal film (base film)

3‧‧‧Main conductive film

4‧‧‧Metal film (cover film)

1 is a schematic cross-sectional view showing an application example of a metal thin film for an electronic component of the present invention.

An application example of the metal thin film of the present invention is shown in Fig. 1. The metal thin film of the present invention is formed, for example, on the substrate 1, and can be used for the base film 2 or the cover film of the main conductive film 3. 4. In FIG. 1, the metal thin film 2 and the metal thin film 4 are formed on both surfaces of the main conductive film 3, and only one of the base film 2 or the cover film 4 may be covered, and may be appropriately selected. Further, in the case where only one side of the main conductive film is covered by the metal thin film of the present invention, the other surface of the main conductive film 3 can be covered with a metal thin film having a composition different from that of the present invention depending on the use of the electronic component.

The present invention can provide a novel metal thin film which can improve moisture resistance and oxidation resistance, and can maintain a low resistance value, for example, in a heating step at the time of lamination with Cu or Al forming a main conductive film. In the metal thin film, one or more element atoms A selected from the group consisting of Cr, Zr, and Ta are added in an amount of 3 atomic % or more, and 10 atom% to 45 atom% of Ni is added, and 50 atom% is added in total. An element selected from the above element group A and the above Ni are added in the following range. Hereinafter, the metal thin film of the present invention will be described in detail. In the following description, the term "moisture resistance" refers to the difficulty in changing the resistance value of the wiring film in a high-temperature and high-humidity environment. In addition, the term "oxidation resistance" refers to the deterioration of electrical contact properties in a high-temperature environment, and can be confirmed by discoloration of the wiring film, and can be quantitatively evaluated by, for example, reflectance.

Regarding the metal thin film of the present invention, the reason why Ni is added to the molybdenum alloy is to improve the oxidation resistance. When pure molybdenum is heated in the atmosphere, it is easily oxidized, causing discoloration of the surface of the metal film, resulting in deterioration of electrical contact. The metal thin film of the present invention can improve oxidation resistance by adding a specific amount of Ni to Mo. When the amount of Ni added is 10 atom% or more, the effect is remarkable.

Cu used as the main conductive film is an element which is easily oxidized if heated in the atmosphere. When the metal thin film of the present invention is used as a cover film of a main conductive film containing Cu, the amount of Ni added is preferably 20 atom% or more. Thereby, the metal film of the invention can ensure sufficient oxidation resistance up to 300 ° C and above. Sex and low resistance values.

On the other hand, Al used as the main conductive film is an element which, when exposed to the atmosphere, forms a thin passive film on the surface thereof to protect the inside, and thus is superior in oxidation resistance and moisture resistance to Cu. However, as described above, in order to improve the contact with ITO or the like, a cover film of a Mo-based alloy is required. Further, since Ni is an element which is easily thermally diffused with respect to Al, the amount of Ni contained in the molybdenum alloy needs to be minimized to improve oxidation resistance.

When the metal thin film of the present invention is used as a cover film of a main conductive film containing Al, when the amount of Ni added exceeds 25 atom%, the cover film is heated in a heating step of about 350 ° C when manufacturing an electronic component such as FPD. The Ni contained in the diffusion diffuses into the Al of the main conductive film, and it is difficult to maintain a low resistance value. Therefore, when the metal thin film of the present invention is used as a cover film of a main conductive film containing Al, it is preferable to set the addition amount of Ni to 25 atom% or less.

According to the study by the inventors, it was confirmed that the moisture resistance of pure molybdenum is low, and the resistance value increases in a high-temperature and high-humidity environment. In the metal thin film of the present invention, in order to maintain the excellent barrier properties of Mo and improve the moisture resistance, the total of one or more elements selected from the element group A of Cr, Zr, and Ta is 3 atom% or more, and The total of Ni is set to 50 atom% or less. The reason for this is that when the total amount of addition of Ni and Cr, Zr, and Ta exceeds 50 atom%, the resistance value increases when heated to a high temperature of 350 ° C or higher. The reason is considered to be that Ni, Cr, or the like is an element which is more likely to thermally diffuse into Cu than Mo.

The element group A of Cr, Zr, and Ta is an element having higher corrosion resistance than Mo, a metal having a property of being easily bonded to oxygen or nitrogen, and having a passive film formed on the surface in a high-temperature and high-humidity environment to protect the metal film. Internal effect. Therefore, regarding this issue The bright metal film can greatly improve the moisture resistance by adding a specific amount of Cr, Zr, and Ta to Mo. This effect is clear when the total amount is 3 atom% or more, and the effect is more remarkable when it is 5 atom% or more.

On the other hand, when the addition amount of the element group A is increased, a passivation film is formed on the metal thin film, and the corrosion resistance is excessively improved. As a result, when the metal thin film is processed into an electrode or a wiring such as an FPD, the etching rate is lowered, and a residue is generated on the substrate or etching is impossible. The amount of addition varies depending on the element, and when Cr or Zr is added, it is preferably 20 atom% or less in total, and when Ta is added, it is preferably 15 atom% or less.

When the metal thin film of the present invention is used for a cover film of a main conductive film, in order to stably obtain a low resistance value, moisture resistance, or oxidation resistance, the film thickness is preferably 20 nm to 100 nm. When the film thickness of the metal thin film is less than 20 nm, the continuity of the metal thin film is lowered, and the above characteristics cannot be sufficiently obtained. On the other hand, when the film thickness of the metal thin film exceeds 100 nm, the electric resistance value of the metal thin film itself becomes high.

In particular, when the main conductive film is Cu, it is more preferable to set the thickness of the metal thin film to 30 nm or more in order to suppress oxidation. Further, when the main conductive film is Al, in order to suppress diffusion of atoms during heating, the thickness of the metal thin film is preferably thin, and more preferably 20 nm to 70 nm.

When forming the metal thin film of the present invention, it is most suitable as a sputtering method using a sputtering target. The following method can be applied: a method of forming a film using a molybdenum alloy sputtering target having the same composition as that of a metal film, or a sputtering using a Mo-Ni alloy sputtering target and Mo-Cr, Mo-Zr, Mo-Ta alloy A method in which a plating target is formed by co-sputtering or the like. Easiness in setting the conditions of the sputtering or easy to obtain the desired composition In terms of the metal thin film, it is preferable to perform sputtering using a molybdenum alloy sputtering target having the same composition as that of the metal thin film.

The molybdenum alloy sputtering target for forming a metal thin film of the present invention contains 10 atom% to 45 atom% of Ni, and contains at least one atomic group A selected from the group consisting of Cr, Zr, and Ta of 3 atom% or more, and contains 50 or more in total. An element selected from the above element group A of at least atomic % and the above Ni, and the remainder contains Mo and unavoidable impurities.

Further, when Cr and/or Zr are selected as the element group A, it is preferable to add the amount thereof to a total of 3 atom% to 20 atom%. Further, when Ta is selected as the element group A, it is preferable to set the amount of addition to 3 atom% to 15 atom%.

In order to secure the oxidation resistance and the moisture resistance at the time of forming a metal thin film, the molybdenum alloy sputtering target for forming a metal thin film of the present invention is preferably an unavoidable impurity other than Mo in addition to Mo and Ni which are essential elements. The content of the remainder other than Cr, Zr, and Ta is small. Oxygen, nitrogen, or carbon as a gas component, Fe, Cu as a transition metal, and unavoidable impurities such as Al or Si as a semimetal may be contained in a range that does not impair the effects of the present invention. For example, oxygen gas and nitrogen gas as gas components are each 1000 ppm by mass or less, carbon is 200 ppm by mass or less, Fe and Cu are 200 ppm by mass or less, and Al and Si are 100 ppm by mass or less, and it is preferable to use a purity other than the gas component. It is 99.9 mass% or more.

As a method of producing a sputtering target for forming a metal thin film for an electronic component of the present invention, for example, a powder sintering method can be applied. In the powder sintering method, for example, a mixed powder obtained by mixing a plurality of alloy powders or pure metal powders as a final composition of the present invention can be used as a raw material powder. As the sintering method of the raw material powder, pressure sintering such as hot press pressing, hot pressing, spark plasma sintering, extrusion sintering, or the like can be used.

[Example 1]

First, Mo powder having an average particle diameter of 6 μm, Ni powder having an average particle diameter of 100 μm, Cr powder having an average particle diameter of 150 μm, Ta powder having an average particle diameter of 120 μm, and Nb powder having an average particle diameter of 85 μm were prepared. The mixture was mixed so as to have a predetermined composition shown in Table 1, and after filling it into a can made of mild steel, vacuum degassing was performed while heating, and the gas in the tank was removed and sealed. Next, the sealed can was placed in a hot-pressure press apparatus, and after sintering at 800 ° C, 120 MPa, and 5 hours, a sputtering target having a diameter of 100 mm and a thickness of 5 mm was produced by mechanical processing.

Further, a Ni-Zr alloy sputtering target for producing a metal thin film of a Mo-Ni-Zr alloy of the following comparative example was produced by a vacuum melting-casting method, and was machined to have a diameter of 100 mm. Sputter target with a thickness of 5 mm.

Each of the sputtering targets obtained above was welded to a copper backing plate and mounted in a sputtering apparatus. The sputtering apparatus was SPF-440H manufactured by Canon Anelva Co., Ltd.

A metal film of each composition shown in Table 1 at 200 nm was formed on a glass substrate of 25 mm × 50 mm to obtain a sample. Further, the metal thin film of the Mo-Ni-Zr alloy is formed by a co-sputtering method in which the target of the Mo-Ni alloy and the Ni-Zr alloy produced as described above is simultaneously sputtered. The composition analysis of the obtained metal thin film was carried out by using ICP (Inductively Coupled Plasma Luminescence Analysis Apparatus) of the model: ICPV-1017 manufactured by Shimadzu Corporation.

The evaluation of the oxidation resistance was performed by measuring the change in reflectance after heating each of the samples obtained above in the air at 250 ° C, 300 ° C, and 350 ° C for 1 hour. When measuring reflectance, use Konica Minolta Co., Ltd. The spectrophotometer CM-2500d was used to measure the reflection characteristics in the visible light region. The etchability was evaluated by immersing each of the samples obtained above in an etchant for Al manufactured by Kanto Chemical Co., Ltd. for 10 minutes, and evaluating whether or not a metal thin film remained on the substrate. The film was left to be etched without any film residue, residue, or the like on the substrate, and the film was left without being etched. Further, in the case where it is etched but there is a film residue or residue, the state is expressed. The results are shown in Table 1.

As shown in Table 1, it was confirmed that if a metal thin film containing pure molybdenum or a molybdenum alloy is heated in the atmosphere or placed in a high-temperature and high-humidity environment, the reflectance tends to decrease, and there is a decrease in reflectance depending on the added element. Big difference.

The reflectance of the metal thin film containing Mo-10 atom% Nb and Mo-17 atom% Ta alloy was confirmed to be such that the reflectance greatly decreased at 300 ° C when heated in the air, and became an oxide at 350 ° C. Transmission, low oxidation resistance. Further, when the metal film containing the Mo-Ni alloy was placed in a high-temperature and high-humidity environment, it was confirmed that when it was left for 100 hours, the reflectance was largely lowered and the moisture resistance was low.

On the other hand, it has been confirmed that the metal thin film containing the molybdenum alloy of Ni and Cr, Zr, and Ta in a specific range of Mo in the present invention is less likely to have a lower reflectance even when heated in the atmosphere and placed in a high-temperature and high-humidity environment. It can combine both oxidation resistance and moisture resistance.

[Embodiment 2]

Assuming that the film structure shown in FIG. 1 was formed, a base film having the composition shown in Table 2 was formed on a glass substrate of 25 mm × 50 mm, and the same sputtering apparatus as that of Example 1 was used, and the film thicknesses shown in Table 2 were respectively used. A Cu film as a main conductive film was formed on the upper surface of the base film, and a cover film was formed on the upper surface of the Cu film to obtain a sample of the laminated wiring film. Further, the Cu target was produced by cutting out an oxygen-free copper plate of Hitachi Cable Co., Ltd.

The evaluation of the oxidation resistance was performed by measuring the change in reflectance after heating each of the samples obtained above in the air at 250 ° C, 300 ° C, and 350 ° C for 1 hour. When the reflectance was measured, the reflection characteristics in the visible light region were measured using a spectrophotometer CM-2500d manufactured by Konica Minolta Co., Ltd. In addition, the evaluation of the moisture resistance was carried out by measuring the high temperature and high humidity of each sample obtained above at 85 ° C × 85%. The change in resistance value in the case of being placed in the environment for 100 hours, 200 hours, and 300 hours. When the resistance value was measured, it was measured using a four-terminal thin film resistivity meter MCP-T400 manufactured by Dia Instruments. The etchability was evaluated by immersing each of the samples obtained above in the Cu etchant Cu02 manufactured by Kanto Chemical Co., Ltd. for 10 minutes, and evaluating whether or not a metal thin film remained on the substrate. The substrate was marked as ○ without any film residue or residue on the substrate, and the residue was not marked as ×. The results are shown in Table 2.

As shown in Table 2, when the Cu film monomer of the main conductive film is heated at 250 ° C or higher in the atmosphere, oxidation occurs, and the reflectance is greatly lowered, and the resistance value cannot be measured. In addition, when the laminated wiring film of the molybdenum alloy and the Cu which is a metal thin film of the comparative example is heated in the atmosphere, the reflectance is lowered, and the resistance value tends to increase. In particular, regarding pure molybdenum, Mo-10 atom% Nb, and Mo-17 atom% Ta, when heated at 350 ° C in the atmosphere, the reflectance is greatly lowered. Further, although the resistance value can be maintained at a low value up to 250 ° C, it is greatly increased at 350 ° C. It is considered that oxygen is transmitted through the cover film, and the Cu film of the main conductive film is oxidized to confirm that the oxidation resistance is low. Further, in the laminated wiring film of the metal thin film using the Mo-Ni alloy of the comparative example, it is found that when the amount of addition of Ni is increased, the decrease in reflectance is suppressed, and the low resistance value can be maintained up to a higher temperature, and the oxidation resistance can be improved. Sex.

In addition, in a high-temperature and high-humidity environment, the reflectance of the Cu layer monomer decreases as the standing time increases, and the resistance value increases. When it is left for 200 hours or more, it becomes impossible to measure a resistance value. In the comparative examples, Mo-10Nb and Mo-17Ta have a lower reflectance than Mo, and the increase in the resistance value is suppressed, and the moisture resistance is improved. Further, it was found that the pure molybdenum also had a large decrease in reflectance at a standing time of 100 hours, and the electric resistance value was increased. When the amount of Ni added was increased, the tendency became remarkable and the moisture resistance was low.

On the other hand, it has been confirmed that when a metal thin film containing a specific range of Ni and a molybdenum alloy of Cr, Zr, and Ta added to Mo is used for the base film and the cover film, heating is performed in an atmosphere of 350 ° C. Even if it is placed in a high-temperature and high-humidity environment for a long time, the reflectance is lowered and the resistance value is increased, and the oxidation resistance and moisture resistance can be greatly improved at the same time. Further, it has been found that the addition of Cr, Zr, and Ta has an effect on moisture resistance, but when Cr exceeds 20 at% and Ta exceeds 15 at%, etching is impossible.

As described above, it was confirmed that the metal thin film of the present invention can significantly improve the oxidation resistance and the moisture resistance by using the base film or the cover film of the main conductive film containing Cu, and maintain the low resistance value.

[Example 3]

Assuming that the film structure shown in Fig. 1 was formed, a base film having the composition shown in Table 3 was formed on a glass substrate of 25 mm × 50 mm, and the same sputtering apparatus as in Example 1 was used, and the film thicknesses shown in Table 3 were respectively used. An Al film as a main conductive film was formed on the upper surface of the base film, and a cover film was formed on the upper surface of the Al film to obtain a sample of the laminated wiring film. In addition, the Al target was purchased from Sumitomo Chemical Co., Ltd.

The evaluation of oxidation resistance and moisture resistance was carried out in the same manner as in Example 2. The etchability was evaluated by applying a photoresist to only half of the sample obtained above and drying it, and immersing it in a mixed acid etching solution for Al manufactured by Kanto Chemical Co., Ltd., and etching the uncoated portion. . Thereafter, the substrate was washed with pure water and dried, and the vicinity of the boundary between the dissolved portion and the undissolved portion coated with the photoresist was observed with an optical microscope. The film was left to be etched without any film residue, residue, or the like on the substrate, and the film was left without being etched. Further, in the case where it is etched but there is a film residue or residue, the state is expressed. The results are shown in Table 3.

As shown in Table 3, in the same manner as in the results of Example 1 and Example 2, it was found that Mo is inferior in oxidation resistance and moisture resistance, Mo-Nb alloy is low in oxidation resistance, and Mo-Ni alloy is in moisture resistance. Poor in terms of sex.

On the other hand, it has been found that when a metal thin film containing a specific range of Ni and a molybdenum alloy of Cr, Zr, and Ta added to Mo is used for the base film and the cover film, the oxidation resistance and the resistance can be greatly improved. Wet.

As described above, it was confirmed that the metal thin film of the present invention can greatly improve the oxidation resistance and the moisture resistance by using the base film or the cover film of the main conductive film containing Al, and maintain the low resistance value.

1‧‧‧Substrate

2‧‧‧Metal film (base film)

3‧‧‧Main conductive film

4‧‧‧Metal film (cover film)

Claims (6)

A metal thin film containing at least one atomic group A selected from the group consisting of Cr, Zr, and Ta in a total amount of 3 atom% or more, containing 10 atom% to 45 atom% of Ni, and a total of 50 atom% or less. The element selected from the above element group A and the above Ni, the remainder contains Mo and unavoidable impurities. The metal thin film according to claim 1, wherein the element selected from the element group A is Cr and/or Zr, and the total amount thereof is 3 atom% to 20 atom%. The metal thin film according to claim 1, wherein the element selected from the above element group A is Ta, and the amount thereof is from 3 atom% to 15 atom%. A molybdenum alloy sputtering target for forming a metal thin film, which is characterized in that it contains at least one atomic group A selected from the group consisting of Cr, Zr and Ta in an amount of 3 atom% or more, and contains 10 atom% to 45 atom% of Ni. Further, it contains 50 atom% or less of the element selected from the above element group A and the above Ni, and the remainder contains Mo and unavoidable impurities. The molybdenum alloy sputtering target for forming a metal thin film according to claim 4, wherein the element selected from the element group A is Cr and/or Zr, and the total amount thereof is 3 atom% to 20 atom%. . The molybdenum alloy sputtering target for forming a metal thin film according to the fourth aspect of the invention, wherein the element selected from the element group A is Ta, and the amount thereof is from 3 atom% to 15 atom%.