JP2006310814A - Thin film wiring layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin film wiring layer which is effective as a wiring layer for a flat surface indicator and capable of also improving a moisture resistance, while ensuring a wet etching nature and a heat resistance. <P>SOLUTION: The thin film wiring layer is formed on a substrate consists of a main conductor layer making Ag or Cu a principal component, and a coating layer overlies an upper layer and/or a lower layer of the main conductor layer. The coating layer contains Cu of 1 to 25 atom% as an addition element, and one or two kinds or more addition elements of 1 to 25 atom% selected from (Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W), and a total amount of the addition elements is made 35 atom% or less, and a remaining portion is the thin film wiring layer consisting of unescapable dopant and Ni. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thin film wiring layer used for a thin film electronic component manufactured by forming a thin film on a substrate.

  For example, as a flat panel display (hereinafter referred to as FPD) manufactured by laminating a thin film on a glass substrate or Si wafer, a liquid crystal display (hereinafter referred to as LCD), a plasma display panel (hereinafter referred to as PDP). ), Field emission display (hereinafter referred to as FED), electroluminescence display (hereinafter referred to as ELD), electronic paper, and other various new products are actively researched and developed.

  For the FPD wiring layer, a high melting point metal such as Cr or Mo or an alloy film thereof is used in consideration of adhesion to the substrate and heat resistance. Further, when further low resistance is required, a thin film wiring layer in which a lower resistance film such as Al or Al alloy and a refractory metal material are stacked is used. Furthermore, the resistance of the wiring layer needs to be reduced in order to increase the size and definition of the display, and materials mainly composed of Ag, Cu, etc. having a lower resistance than Al have been proposed.

However, Ag and Cu have a problem that adhesion to a substrate or the like is low and weather resistance is poor. For this reason, an Ag alloy or Cu alloy in which an additive element is added to Ag or Cu has been proposed, but sufficient adhesion to the substrate and weather resistance have not been ensured.
For this reason, it is considered that even a film mainly composed of Ag or Cu is effective to form a laminated film with a refractory metal in the same manner as an Al film or an Al alloy film.

For example, the Cr film is excellent in corrosion resistance and heat resistance, can be wet etched using a chemical solution, has high adhesion to a substrate such as a glass substrate or Si wafer, and is a base film of a material mainly composed of Ag, Cu, or the like. As a useful material.
In addition, since the Mo film is a high melting point material like the Cr film, the heat resistance is high, and the adhesion to a glass substrate for a flat display device, a Si wafer or the like is also good. Furthermore, although there is an advantage that wet etching is possible, the moisture resistance is particularly inferior to the Cr film among the weather resistance. For this reason, a Mo alloy film with improved moisture resistance of the Mo film has been proposed as a base film (see, for example, Patent Documents 1 to 3).
JP 2001-192752 A JP 2004-91907 A JP 2004-140319 A

In Patent Documents 1 to 3, in the formation of an FPD wiring film, the upper and lower layers of Ag, Cu, or an alloy film thereof are coated with Cr, Mo, or an alloy thereof to improve adhesion and weather resistance. It has been proposed that there is an effect on improving the performance.
Cr that covers Ag or Cu is a useful material for improving adhesion to a substrate or the like and improving weather resistance, but when manufacturing an FPD element, discarding it, or recycling it. There is a problem such as the generation of waste liquid containing hexavalent Cr, and it is necessary to reduce the use for global environmental conservation.

  In addition, when Mo is the main component, there is a problem that Mo or Mo alloy is preferentially corroded by battery action because wet etching with a laminated film of Ag or Cu causes a large electrode potential difference.

  An object of the present invention is a wiring layer having a coating film for solving the above-described problems and maintaining the low resistance characteristics of the main conductor layer mainly composed of Ag or Cu, and is formed by wet etching. It is an object of the present invention to provide a novel thin film wiring layer that can be patterned.

As a result of various studies, the inventor has not made Cr or Mo as a main component, but a Ni alloy film in which a specific additive element is used for a film containing Ni as a main component, and a wiring mainly containing Ag or Cu. It was found that a thin film wiring layer capable of wet etching can be obtained by laminating as a covering layer of the layer, and the present invention has been achieved.
That is, the present invention is a thin film wiring layer formed on a substrate, comprising a main conductor layer mainly composed of Ag or Cu and a covering layer covering the upper layer and / or the lower layer of the main conductor layer, The layer contains 1 to 25 atomic% of Cu as additive elements, and 1 to 25 atomic% of one or more elements selected from (Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W). The thin film wiring layer contains the total amount of additive elements of 35 atomic% or less, and the balance is inevitable impurities and Ni.

When the main conductor layer is a layer containing Ag as a main component, the coating layer contains 1 to 25 atomic% of Cu as an additive element and one element selected from (Ti, Zr, Hf) or It is preferable that the thin film wiring layer contains 1 to 10 atomic% of two or more elements, the total amount of additive elements is 35 atomic% or less, and the balance is inevitable impurities and Ni.
When the main conductor layer is a layer containing Cu as a main component, the coating layer has 1 to 25 atomic% of Cu as an additive element and one or two selected from (V, Mo, W). It is preferable that the thin film wiring layer contains 5 to 25 atomic% of the above elements, the total amount of additive elements is 35 atomic% or less, and the balance is inevitable impurities and Ni.
Preferably, the coating layer is a thin film wiring layer containing 1 to 10 atomic% of one or more elements selected from (Al, Si, Ge) as an additive element.
Preferably, the coating layer is a thin film wiring layer having a thickness of 5 nm to 100 nm.

  The thin film wiring layer of the present invention can maintain the main conductor layer mainly composed of Ag or Cu at a low resistance and can form a wiring pattern by wet etching. It becomes extremely effective as a wiring layer of a TFT for a flat panel display device that does not like changes.

An important feature of the present invention is that, in a thin-film wiring layer having a structure composed of a main conductor layer mainly composed of Ag or Cu and a covering layer covering the main conductor layer, Ni instead of Cr or Mo, which has been conventionally applied as a covering layer. The alloy is applied.
The Ni alloy layer applied to the present invention will be described below.

Since the electrode potential of Ni is close to Ag and Cu, when wet etching is performed as a thin film wiring layer of a laminated film, a wiring pattern can be formed and the Ni alloy layer is preferentially corroded by battery action. Therefore, a highly reliable laminated thin film wiring layer can be obtained. This is the most important feature of the present invention.
In addition, since Ni has a high electrode potential and is not easily oxidized, it can ensure significantly superior weather resistance compared to Mo. When Ni alloy film is coated on the upper layer of the main conductor layer as a cap layer, the weather resistance is It also has the effect that it can be secured. In addition, since Ni has a higher melting point than Ag and Cu and is easily oxidized, when it is formed on the glass substrate or the like as an underlayer of the main conductor layer, an oxide or the like is generated at the interface and aggregates. Since it becomes difficult, it has the effect that adhesiveness improves.

  In forming a wiring layer, it is not preferable to have ferromagnetism because it may be magnetized by an induced magnetic field when energized to cause a characteristic change. Since Ni is an element having ferromagnetism, it is necessary to reduce the magnetism by adding a certain additive element to Ni. Further, since Ni has a melting point near 1400 ° C. and a melting point higher than that of the main conductor layer mainly composed of Ag or Cu, when it is formed as a cap layer on the main conductor layer, it has a certain degree of heat resistance. Although the heat resistance is inferior to that of Mo, which is a refractory metal, it is effective to add an additive element in order to suppress the deterioration of the film during heating.

  Therefore, in the present invention, the coating layer is selected from 1 to 25 atomic% of Cu as an additive element with respect to Ni (Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W) 1 A Ni alloy containing 1 to 25 atomic percent of seeds or two or more additive elements is used.

The reason why Cu is added to Ni is that it has an effect of improving wet etching properties as a laminated film with the main conductor layer. That is, Cu is easily dissolved in Ni, and the electrode potential can be brought close to Ag and Cu. Therefore, a thin film layer mainly composed of Ag or Cu of the main conductor layer and a coating layer mainly composed of Ni Thus, the difference in etching rate during wet etching can be suppressed. It also has the effect of reducing the magnetism of Ni.
The effect appears from 1 atomic%, and becomes more noticeable at 3 atomic% or more. However, if the content exceeds 25 atomic%, the developer or resist stripping solution when performing photolithography in wet etching is used. Since corrosion easily occurs and heat resistance decreases, the amount of Cu added to Ni is set to 1 to 25 atomic%.

  Further, in order to reduce the magnetism of Ni, together with the addition of Cu, it is selected from Ti, Zr, Hf of 4A group element, V, Nb, Ta of 5A group element, Cr, Mo, W of 6A group element 1 to 25 atomic% of one or more elements are added. Although it is considered that the magnetic properties can be reduced by adding to Ni other than metallic elements having ferromagnetic properties such as Fe and Co, these elements can reduce the magnetic properties of Ni, particularly with a small addition amount. Is an effective element for peeling. In addition, the effect by these additional elements appears from 1 atomic% or more by compound addition with Cu, and becomes remarkable at 3 atomic% or more. On the other hand, if it exceeds 25 atomic%, Ti, Zr, Hf, Nb, Ta, and Cr have high corrosion resistance, and wet etching property is lowered, which may make it difficult to form a wiring pattern. On the other hand, when V, Mo, and W exceed 25 atomic%, the corrosion resistance is greatly lowered. For this reason, the addition amount of these elements is set to 1 to 25 atomic%.

  As described above, the additive element added to Ni has various effects. However, when the Ni alloy film is used as a coating layer and a thin-film wiring layer laminated with a main conductor layer mainly composed of Ag or Cu, the wet etching property is improved. Since it is important, the total amount of additive elements needs to be 35 atomic% or less. This is because if the total amount of additive elements exceeds 35%, residues are likely to occur during wet etching. In addition, if the total amount of additive elements exceeds 35 atomic%, peeling may occur between the Ni alloy film and the substrate, or the adhesion between the Ni alloy film and the main conductor layer may be reduced. The total amount of additive elements is preferably within the above range. The cause of this decrease in adhesion is considered to be due to the fact that the crystal structure of the Ni alloy film changes and becomes amorphous easily due to an excessive amount of the additive element.

Further, when the main conductor layer contains Ag as a main component, the adhesion between the Ni film and the layer containing Ag as a main component is not necessarily high and may be peeled off in some cases. The reason is considered to be because Ag and Ni are element systems that separate into two phases. For this reason, in order to improve the adhesion between Ni and Ag, addition of Cu, which is an element having a solid solution region with both, is effective, and is an element that forms a compound with both Ag and Ni (Ti, Zr). , Hf) is particularly effective.
The effect of improving the adhesion of these elements can be obtained even from 1 atomic%, but if it exceeds 10 atomic%, depending on the amount of Cu added, the wet etching property may be reduced, or depending on the heating temperature, the additive element may be changed to Ag. Since it may diffuse and increase the resistance value, it is preferably contained in the range of 1 to 10 atomic%. Of these elements, industrially inexpensive Ti is more desirable.
In the case where wet etching is performed on a laminated wiring layer having a main conductor layer of Ag and a main component of Ni, it is preferable to use an etchant in which phosphoric acid, nitric acid, acetic acid, and water are mixed.

Further, when the main conductor layer is mainly composed of Cu, it is preferable to add 5 to 25 atomic% of (V, Mo, W) together with Cu as the Ni alloy of the coating layer. That is, when the heat treatment is performed, Ni in the coating layer may diffuse into the main conductor layer mainly composed of Cu and increase the resistance value, so that Ni has a solid solution region and is separated from Cu. This is because by adding (V, Mo, W), which is an element, to the Ni alloy, Ni in the coating layer is prevented from diffusing into Cu in the main conductor layer. The effect of addition of these elements becomes clear at 5 atomic% or more, and if it exceeds 25 atomic%, a problem arises in corrosion resistance, so 5 to 25 atomic% is preferable. Of V, Mo, and W, industrially inexpensive Mo is most desirable.
Note that an etchant in which ammonium persulfate, nitric acid, and water are mixed is preferably used to etch a film in which the main conductor layer is Cu and a layer having a Ni main component is laminated. Also in this etchant, it is desirable to add Cu in order to improve the etchability of the Ni alloy.

  In the present invention, it is desirable that 1 to 10 atomic% of (Al, Si, Ge) is further contained in addition to the above elements as an element added to Ni. Al, Si, and Ge have the effect of densifying the film structure of the Ni alloy film, further improving heat resistance, and improving the adhesion to the substrate and the like. Since these elements have a solid solution region with respect to Ni and easily develop a compound, the film can be densified by suppressing the growth of crystal grains of the film. These effects appear even when Al, Si, and Ge are added from 1 atomic%, but when combined with Cu or the above elements, the film tends to become amorphous when it exceeds 10 atomic%, and adhesion is improved. It may be reduced or a residue may be generated during etching.

  The main conductor layer mainly composed of Ag or Cu of the present invention is a layer made of 99 atomic% or more of Ag or Cu containing pure Ag or pure Cu in order to make the main conductor layer have a lower resistance. It is desirable.

The configuration of the present invention is a thin-film wiring layer formed on a substrate, and includes a main conductor layer mainly composed of Ag or Cu and a covering layer covering the main conductor layer, and the covering layer is as described above. Although it is made of a Ni alloy, in order to improve adhesion, the underlayer of the main conductor layer containing Ag or Cu as a main component is used as an underlayer, and in order to ensure weather resistance, Ag or Cu is used as a main component. A cap layer is formed on the main conductor layer. It is also effective to form a thin film wiring layer formed on both. Also in this case, the Ni alloy film of the present invention can be collectively wet etched with the main conductor layer mainly composed of Ag or Cu.
When the main conductor layer is Ag, the Ni alloy film is particularly effective as a base film because of its low adhesion to the substrate and the oxidation protective film. Further, when the main conductor layer is Cu, using a Ni alloy film as a coating layer is effective in suppressing Cu diffusion, and is particularly effective as a barrier film of a thin film transistor wiring as a switching element such as a liquid crystal display. An effect can be obtained.

  In the thin film wiring layer of the present invention, the coating layer preferably has a thickness of 5 nm to 100 nm. If the thickness is less than 5 nm, the continuity as the coating layer is not sufficient, and sufficient adhesion cannot be obtained when the base film of the main conductor layer mainly composed of Ag or Cu is used. Moreover, it is because the weather resistance at the time of setting it as a cap layer is not fully obtained. Further, when the layer thickness exceeds 100 nm, it takes time to form a film and the wet etching time becomes long, which is not desirable in terms of production efficiency. Further, in the thin film wiring layer, since the resistance value of the wiring layer is determined by the configuration of both the main conductor layer and the covering layer, when the lamination ratio of the Ni alloy film having a higher resistance value increases, the low resistance Ag or The resistance value of the thin film wiring layer laminated with Cu increases. For this reason, it is desirable that the coating layer made of the Ni alloy film secures adhesion and weather resistance, and is effective even if it is as thin as possible, more preferably 5 to 100 nm, and even more preferably 5 to 50 nm. .

  The layer thickness of the main conductor layer mainly composed of Ag or Cu is preferably 100 to 350 nm. The reason is that if the thickness is less than 100 nm, the thickness of the layer is thin and the effect of surface scattering is large and it is difficult to obtain a sufficiently low resistance value. This is because even if the thickness is increased, the effect of reducing the specific resistance value is low.

  In order to form the thin film wiring layer of the present invention, sputtering is desirable. Further, in order to form the coating layer of the present invention, a target material mainly composed of Ni having the same composition is required. However, Ni is a magnetic material, and there is a problem that the efficiency of magnetron sputtering is poor. However, the composition of the Ni alloy in the coating layer of the present invention also has the effect of reducing or eliminating magnetism due to the effect of the additive element, and it is possible to increase the efficiency during magnetron sputtering. Also become.

Further, as a configuration of the thin film wiring layer in the present invention, when a coating layer mainly composed of Ni is formed on a substrate and a main conductor layer is formed thereon, the main conductor mainly composed of Ag or Cu. It is also possible to improve the heat resistance by suppressing the diffusion of atoms and abnormal grain growth in the layer. This is because Ni, which is the main component of the coating layer, has the same face-centered cubic lattice as Ag or Cu, which is the main conductor layer, and is easily oriented in the (111) plane. In the case of forming a film mainly composed of Ag or Cu having a crystal, the main conductor layer grows on the crystal close-packed surface and has a high (111) plane orientation. This is thought to be due to the suppression of grain growth and the occurrence of partial abnormal grains. In particular, Cu is more easily oxidized than Ag, and the film forming interface is oxidized on the substrate on which the film is formed and the protective film, and it is difficult to obtain a (111) oriented film. It is effective as
Note that the above-described improvement in heat resistance has a particularly high effect in the range in which the coating layer containing Ni as a main component maintains the face-centered cubic lattice structure.

  The board | substrate which forms the thin film wiring layer of this invention is not specifically limited, It can apply to the board | substrate which has insulation with smooth surfaces, such as a silicon substrate, a glass substrate, and a resin substrate. In particular, it is particularly suitable on a glass substrate having high heat resistance and excellent surface smoothness. The main conductor layer and the coating layer in the thin film wiring layer of the present invention can be formed by a sputtering method using a target material having substantially the same composition as each layer.

Further, since the thin film wiring layer of the present invention can provide a wiring layer having a lower resistance than that of an Al alloy or an Al laminated film, wiring of a liquid crystal display or an organic EL display driven by a currently mainstream thin film transistor (TFT). Useful as a layer.
In particular, the thin film wiring layer according to the present invention can form a base film or a cap film coated with a highly weather-resistant Ni alloy film on a main conductor layer mainly composed of Cu and Ag, so that moisture released from an organic light emitter is formed. It is effective for organic EL displays that require high weather resistance that does not change with respect to the emitted gas. Similarly, it is useful to use in a sheet display or the like in which a wiring film is formed on a resin substrate or a resin insulating film that is easily permeable to moisture and easily released. In particular, it is highly effective when used as a thin-film wiring layer having Cu as a main conductor layer, which has a low weather resistance and is easily deteriorated.

  A predetermined amount of Cu, Ti, Nb, Ta, Si, Ge, Mo, W, 99.3% or more of V, Zr, and Hf is added to high purity electrolytic Ni to a vacuum induction melting furnace. And was cast into a metal mold having a thickness of 50 mm, a width of 200 mm, and a height of 300 mm to produce an ingot having the composition shown in Table 1. After that, it was made into a plate shape by plastic working and further machined to obtain Ni alloy target materials of various compositions having a predetermined size. At the same time, a target material of Cr, Mo, pure Ag, pure Cu, and Ag-0.5 atomic% Si-0.3 atomic% Ge was prepared.

  Using the prepared target material, argon pressure: 0.5 Pa, input power: 500 W, substrate heating temperature 120 ° C., thickness 0.7 × 100 mm × 100 mm Corning 1737 glass substrate, Si wafer A Ni alloy film, a Mo film, and a Cr film having a film thickness of 10 to 100 nm are formed on a polycarbonate resin film substrate, and a 200 nm pure Ag film, a pure Cu film, and Ag-0.5 atomic% are formed thereon. A sample was prepared in which a Si-0.3 atomic% Ge alloy film and, if necessary, a 20-30 nm Ni alloy film was formed thereon as a cap layer. Moreover, the sample which formed Ag and Cu directly on the glass substrate at 200 nm as a comparative example was also produced.

  Using the sample prepared above, the patterning property in wet etching was evaluated. First, an OFPR-800 positive resist manufactured by Tokyo Ohka Co., Ltd. is formed on the laminated film by spin coating, the resist is exposed with ultraviolet rays using a photomask, and then developed with an organic alkali developer NMD-3, and line and space (L / S), a 25 μm resist pattern was prepared. Thereafter, when the main conductor layer is pure Ag or an Ag-0.5 atomic% Si-0.3 atomic% Ge alloy, a mixed aqueous solution of phosphoric acid, nitric acid and acetic acid is used as an etchant. In the case of Cu, a mixed aqueous solution of ammonium persulfate and nitric acid was used as an etchant. After the laminated film having no resist pattern was dissolved, it was immersed and etched for 20 seconds. The resist pattern after etching was completed, the residues around it, and the shape of the pattern edge were observed with an optical microscope. At that time, a wiring pattern was formed, and no residue was evaluated as good. In addition, when it did not melt | dissolve even if it immersed for 15 minutes or more, the etching was complete | finished at that time.

  Further, in the pattern shape of the laminated film, it is most desirable that the edge portion is straight. When observing the pattern shape after etching, the edge straightness of the laminated film is low and the difference between the maximum width and the minimum width exceeds 3 μm, x is 1.5-3 μm, Δ is less than 1.5 μm. evaluated. Further, those having a size of 1 μm or less were evaluated as ◎. Also, after immersing in an organic solvent, cleaning with pure water, spin drying, and removing the resist by performing oxygen ashing, observe the laminated film pattern with an optical microscope. As evaluated. The above observation results are shown in Table 1.

  In addition, sample No. shown in Table 1 In order to confirm the magnetic properties of Ni alloy films having a composition of 1 to 19, a thin film having a film thickness of 100 nm was formed on a Φ8 mm glass substrate, and VSM (vibrating sample magnetometer (BHV-35, manufactured by Riken Denshi)) The magnetic flux density of the thin film when an applied magnetic field of 40 kA / m was applied was also measured by Table 1. The measurement results are also shown in Table 1. As shown in Table 1, all the Ni alloy films have a magnetic flux density of 0. .05 (T) or less, and has a characteristic that there is no problem as a wiring material. Therefore, the target material can also be easily sputtered.

  As shown in Table 1, in the etchant used this time, sample No. 21 underlayer Cr film, sample No. 19 Ni alloy film not containing Cu could not be etched. Sample No. In the Ni alloy film containing 16 Si exceeding 10 atomic%, a residue is generated. Sample No. It can be seen that in the Ni alloy film containing 18% Cu exceeding 25%, the etching of the Ni alloy film is accelerated, and a step is produced between the laminated pure Ag films. Sample No. with Mo as the underlayer was also used. In No. 20, since the Mo film is etched faster than the pure Ag film, the underlayer becomes narrower and the step becomes larger. Sample No. It can be seen that a thin wiring layer having the Ni alloy film shown in 1 to 15 as a coating layer can form a good wiring pattern by wet etching.

Next, an evaluation test was performed as follows for each sample of the laminated film similar to that prepared in Example 1.
First, regarding the electrical conductivity of each prepared sample, the specific resistance value was measured using a four-terminal thin film resistivity meter (manufactured by Mitsubishi Oil Chemical Co., Ltd., MCP-T400) and the film thickness of the sample. It was evaluated from.
As a method for evaluating adhesion, after forming a grid pattern with slits on the surface of the film at intervals of 2 mm, cutting the grid surface with a grid pattern at intervals of 2 mm, and then forming a mending tape 810 (manufactured by Scotch) on the film surface. ) Was attached and peeled off at an angle of 45 ° to confirm the state of film peeling.
Further, as a weather resistance test, a test was conducted by leaving it in an environment of a temperature of 85 ° C. and a relative humidity of 85% for 150 hours, and then the film surface was visually confirmed. In that case, the thing which does not generate | occur | produce discoloration, a white spot, cloudiness, etc. was evaluated as favorable ((circle)). The above measurement and evaluation results are shown in Table 2.

From Table 2, sample No. 1 in which an Ag film or a Cu film was formed directly on the substrate Compared with Samples 22 and 23, Sample No. It can be seen that the adhesion of the laminated film formed by using the 1 to 15 Ni alloy films as the underlayer is greatly improved. In addition, sample No. which does not form a cap layer. In Example 3, white turbidity occurred after the weather resistance test. Sample No. 22 in which the underlayer was formed of Mo and Mo. The level of cloudiness was lower than 20.
In addition, Sample No. in which a Ni alloy film was formed as a cap layer was used. In 1-2, 5-15, even after a weather resistance test, it turns out that discoloration, a white spot, and white turbidity do not generate | occur | produce, but have favorable weather resistance.

It should be noted that sample No. 1 in which a coating layer was formed using a Ni alloy film having a Cu content exceeding 25 atomic% as a base layer and a cap layer was used. No. 18 shows lower adhesion than Ni alloy films containing other Cu and low weather resistance due to discoloration and white spots. Sample No. 1 in which a coating layer was formed using a Ni alloy film having a Mo content exceeding 25 atomic% as a base layer and a cap layer was used. In No. 17, the adhesion is good, but it can be seen that the weather resistance is lowered and discoloration and white spots are generated.
The white spot is a raised part of the film surface due to partial film growth or oxidation of the film. If a white spot occurs, it will cause an electrical or optical defect in the next process of the FPD, so it does not occur. It is desirable.

  In addition, sample No. 1 in which a Ni alloy film to which Si or Ge was added was formed as an underlayer. In 5 and 7, the adhesion is better.

As described above, as shown in Tables 1 and 2, the laminated structure of the present invention example in which the main conductor layer mainly composed of Ag or Cu and the coating layer mainly composed of Ni in the upper layer and / or the lower layer thereof are formed. It can be seen that the wiring pattern by wet etching can be formed satisfactorily. In addition, when the base layer is formed as the lower layer of the main conductor layer, good adhesion can be realized, and when the cap layer is formed as the upper layer of the main conductor layer, good weather resistance can also be realized. I understand.
Moreover, since the specific resistance value increases as the thickness of the coating layer increases, it can be seen that the coating layer is preferably as thin as possible within a range that can ensure weather resistance and adhesion.

Moreover, the heat resistance test was done about the sample which formed Ni alloy as a coating layer in the main conductor layer which has Cu as a main component among the laminated films similar to what was produced in Example 1. FIG.
As a heat resistance test, each sample was subjected to heat treatment in a vacuum atmosphere at a temperature of 250 ° C. for 1 hour, and then measured using a four-terminal thin film resistivity meter (manufactured by Mitsubishi Yuka, MCP-T400). The specific resistance value was calculated from (Ω / □) and the total film thickness of the sample, and evaluated by the change in specific resistance value before and after the heat treatment. Moreover, the film | membrane surface of each sample after a heating test was confirmed visually, and the thing which does not generate | occur | produce discoloration, a white spot, white turbidity, etc. was evaluated as favorable ((circle)). The above evaluation results are shown in Table 3.

  As shown in Table 3, the specific resistance value of each sample when the Ni alloy containing Mo, W, and V together with Cu is used as the coating layer (sample Nos. 9 to 15) does not increase after the heating test. I understand that.

  As described above, the thin film wiring layer of the present invention is required to have high reliability by laminating a film mainly composed of low resistance Cu or Ag and a Ni alloy film excellent in heat resistance, corrosion resistance, and weather resistance. It is optimal for a conductive film for a flat panel display. In addition, it is particularly suitable as a thin film wiring layer for organic EL displays in which a resin is formed on a conductive film, and is used as a thin film wiring layer for flat display devices for mobile devices such as in-vehicle devices that require high reliability. It is possible.

Claims (5)

A thin-film wiring layer formed on a substrate, comprising a main conductor layer mainly composed of Ag or Cu and a coating layer covering the upper layer and / or the lower layer of the main conductor layer, the coating layer being Cu as an additive element 1-25 atomic%, (Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W) containing one or more elements selected from 1 to 25 atomic%, and an additive element A thin film wiring layer characterized in that the total amount of is 35 atomic% or less, and the balance is inevitable impurities and Ni. The main conductor layer is a layer containing Ag as a main component, and the coating layer has 1 to 25 atomic% of Cu as additive elements and one or more elements selected from (Ti, Zr, Hf) The thin film wiring layer according to claim 1, wherein the total amount of additive elements is 35 atomic% or less, and the balance is inevitable impurities and Ni. The main conductor layer is a layer containing Cu as a main component, and the coating layer contains 1 to 25 atomic% of Cu as additive elements and 5 elements of one or more selected from (V, Mo, W). 2. The thin film wiring layer according to claim 1, wherein the thin film wiring layer is contained in an amount of ˜25 atomic%, the total amount of additive elements is 35 atomic% or less, and the balance is inevitable impurities and Ni. 4. The coating layer according to claim 1, wherein the covering layer contains 1 to 10 atomic% of one or more elements selected from (Al, Si, Ge) as an additive element. 5. Thin film wiring layer. The thin film wiring layer according to any one of claims 1 to 4, wherein the coating layer has a thickness of 5 nm to 100 nm.