JP6908164B2 - Ag alloy film - Google Patents

Description

The present invention relates to Ag alloy film containing In, a Ge.

In general, Ag films or Ag alloy films are excellent in optical and electrical characteristics, and are therefore used as reflective films and conductive films for various parts such as reflective electrode films such as displays and LEDs, and wiring films such as touch panels. There is.
It is known that, for example, the reflectance and conductivity when used as a reflective electrode film can be improved by adding a specific element to form an oxide as an Ag alloy film.
For example, Patent Document 1 describes an Ag alloy film in which AgSbMg or AgSbZn is used as an Ag alloy and Sb is used as an oxide. Such an Ag alloy film is said to be excellent in low resistance, heat resistance, and chloride resistance.
Further, for example, Patent Document 2 describes an Ag alloy film in which AgIn is used as an Ag alloy and In is used as an oxide. It is said that such an Ag alloy film can increase the reflectance.
Further, for example, Patent Document 3 describes an Ag alloy film using AgSbAl or AgSbMn as the Ag alloy. Such an Ag alloy film is said to be excellent in low resistance, heat resistance, and chloride resistance.
Further, for example, Patent Document 4 describes an Ag alloy film in which AgSb is used as the Ag alloy and Sb is used as an oxide. Such an Ag alloy film is said to have excellent moisture resistance, sulfurization resistance, and heat resistance, high reflectance, and low resistance.
Here, the various Ag alloy films described above are formed by a sputtering target made of an Ag alloy.

Japanese Unexamined Patent Publication No. 2014-74225 Japanese Unexamined Patent Publication No. 2014-19932. Japanese Unexamined Patent Publication No. 2014-05503 Japanese Unexamined Patent Publication No. 2013-209724

However, the Ag alloy film described in Patent Documents 1-4 described above is not sufficiently improved in heat resistance, and an Ag alloy film having further excellent heat resistance is desired.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an Ag alloy film having excellent heat resistance.

As a result of diligent studies by the present inventors in order to solve the above problems, an Ag alloy film is formed by forming an InGe concentrated portion in which In and Ge are concentrated on the surface side of the Ag alloy containing Ge and In. It was found that the heat resistance of

The present invention has been made based on the above findings, and the Ag alloy film of the present invention is an Ag alloy film composed of an Ag alloy containing In and Ge, and In and Ge are concentrated on the surface side. and have a the InGe concentration portion, the in in InGe concentration portion, Ge is characterized in that is present as at least one or both of oxide and metal.

According to the Ag alloy film of the present invention, an Ag alloy film having excellent heat resistance can be realized by forming an InGe concentrated portion in which In and Ge are concentrated on the surface side.

Here, in the Ag alloy film of the present invention, the Ag alloy contains 0.1% by mass or more and 1.5% by mass or less of In and 0.1% by mass or more and 7.5% by mass of Ge, and the balance. Can also be composed of Ag and unavoidable impurities. The Ag alloy film having such a composition is particularly excellent in heat resistance, and is particularly suitable for, for example, a reflective conductive film application.

Further, in the Ag alloy film of the present invention, the InGe concentrated portion may contain oxides of In and Ge.
By including the oxides of In and Ge, the reflectance can be further improved.

Further, in the Ag alloy film of the present invention, the InGe concentrated portion may be in the range of 0.5 nm or more and 10 nm or less in the film thickness direction from the surface of the Ag alloy film.
By forming the InGe concentrated portion in the above-mentioned range on the surface side of the Ag alloy film, it is possible to prevent a decrease in reflectance while maintaining heat resistance.

Further, in the Ag alloy film of the present invention, the surface roughness (Ra) of the surface of the Ag alloy film may be 0.8 nm or less.
By setting the surface roughness (Ra) to 0.8 nm or less, it is possible to prevent a decrease in reflectance while maintaining heat resistance.

Further, in the Ag alloy film of the present invention, the Ag alloy has a Pd content of 40 mass ppm or less, a Pt content of 20 mass ppm or less, an Au content of 20 mass ppm or less, and a Rh content. Is preferably 10 mass ppm or less, and the total content of Pd, Pt, Au, and Rh is preferably 50 mass ppm or less.
Since Pd, Pt, Au, and Rh, which may be contained in the Ag alloy, act as catalysts in the reduction reaction of nitric acid, when a large amount of these elements is contained, the formed Ag alloy film is etched with a nitric acid etching solution. The etching rate of the film may increase. Therefore, when the Ag alloy contains Pd, Pt, Au, and Rh, the content of Pd, Pt, Au, and Rh is limited as described above, and the etching process is performed using an etching solution containing nitric acid. However, the etching rate can be kept low.

According to the present invention, it is possible to provide an Ag alloy film having excellent heat resistance.

It is a peak graph which shows the result of the depth analysis of In by XPS after the heat treatment of Example 1 about the Ag alloy film containing the InGe concentrated part. It is a peak graph which shows the result of the depth analysis of Ge by XPS after the heat treatment of Example 1 about the Ag alloy film containing the InGe concentrated part.

Hereinafter, an Ag alloy film according to an embodiment of the present invention and a sputtering target for forming the film will be described.
(Ag alloy film)
The Ag alloy film according to the embodiment of the present invention has excellent heat resistance, and is particularly suitable for use as a reflective electrode film formed in contact with an organic layer in an organic EL device, for example.
The Ag alloy film is made of an Ag alloy containing In and Ge, and an InGe concentrated portion in which In and Ge are concentrated is formed on the surface side of the Ag alloy film. This InGe concentration portion is a portion where the concentration of In and Ge is higher than that of other portions. The InGe concentration portion is not formed as a layer in which a clear interface or the like exists between the InGe concentration portion and the surrounding region, and the concentration of In, which gradually changes from the peak position of the concentration of In and Ge, is not formed. It is a concentrated part of Ge concentration.
By forming such an InGe concentrated portion, the heat resistance of the Ag alloy film can be improved.

Ge, which constitutes the InGe concentration portion, functions to enhance the effect of In concentration. For example, when In and Ge are present as oxides in the InGe concentration portion, the presence of Ge promotes the concentration of In oxides as compared with the case where In alone is present as an oxide. As a result, the film thickness of the In oxide increases. By concentrating In and Ge, the purity in the Ag alloy becomes high and approaches sterling silver. On the other hand, transparent oxides of In and Ge are formed on the surface side of the Ag alloy film, and the reflectance is improved.

The InGe concentrated portion may be formed in a range of 0.5 nm or more and 10 nm or less in the film thickness direction from the surface of the Ag alloy film, for example. If the InGe concentrated portion is formed in a range of 0.5 nm or more from the surface of the Ag alloy film, the heat resistance can be enhanced and the deterioration of the sulfurization resistance can be prevented. On the other hand, if the InGe concentrated portion is formed in the range of 10 nm or less from the surface of the Ag alloy film, the reflectance does not decrease.

In the present embodiment, the Ag alloy constituting the Ag alloy film contains 0.1% by mass or more and 1.5% by mass or less of In and 0.1% by mass or more and 7.5% by mass of Ge, and the balance is It is composed of Ag and unavoidable impurities.
Further, in the present embodiment, the above-mentioned Ag alloy has a Pd content of 40 mass ppm or less, a Pt content of 20 mass ppm or less, an Au content of 20 mass ppm or less, and a Rh content of 10 mass ppm or less. It is preferable that the mass is ppm or less and the total content of Pd, Pt, Au and Rh is 50 mass ppm or less.
The Ag alloy may contain one or more selected from Pd, Pt, Au and Rh, and in particular, one selected from Pd, Pt, Au and Rh, Pd, Containing 2 or more types of Pt, 2 or more types of Pd and Au, 2 or more types of Pd and Rh, 2 or more types of Pt and Au, 2 or more types of Pt and Rh, or 2 or more types of Au and Rh. There is. Further, the Ag alloy may contain one kind or two or more kinds selected from Pd, Pt, Au and Rh as one kind of impurities, for example.
The composition of the Ag alloy film referred to here is obtained by forming an Ag alloy film under the following conditions using an Ag alloy sputtering target and analyzing the composition of the Ag alloy film having a thickness of 100 nm by ICP. be.
Film formation power density: 2.0 to 5.0 (W / cm ² )
Film formation gas: Ar
Film formation gas pressure: 0.3 (Pa)
Distance between target and substrate: 70 (mm)

When the concentration of In in the Ag alloy film is 0.1% by mass or more, the sulfurization resistance of the Ag alloy film can be enhanced. Further, when the concentration of In is 1.5% by mass or less, the reflectance does not decrease on the surface side of the Ag alloy film.
On the other hand, when the concentration of Ge is 0.1% by mass or more, the effect of concentrating In is exhibited, and the concentrated portion of InGe can be efficiently formed. Further, when the concentration of Ge is 7.5% by mass or less, the reflectance does not decrease on the surface side of the Ag alloy film.

Noble metal elements such as Pd, Pt, Au, and Rh, which may be contained in the Ag alloy, act as a catalyst in the reduction reaction of nitric acid. Therefore, if a large amount of these elements is contained, the formed Ag alloy film is etched with a nitric acid etching solution. At that time, the etching value becomes high, and there is a risk that the etching process cannot be performed stably.
Therefore, in order to perform a stable etching process using a nitrate etching solution, the content of Pd contained in the Ag alloy should be 40 mass ppm or less, the content of Pt should be 20 mass ppm or less, and the content of Au should be 20 mass ppm or less. It is preferable that the content of ppm or less and Rh is 10 mass ppm or less, and the total content of Pd, Pt, Au and Rh is 50 mass ppm or less. In general, when the Ag alloy contains one or more of Pd, Pt, Au, and Rh, the lower limit of the total content may be 0.1% by mass or more. be.

In and Ge in the InGe concentrated portion may exist as an oxide or as a metal. In particular, when In and Ge are present as oxides in the InGe concentrated portion, the reflectance can be further improved in addition to the heat resistance. In the present embodiment, the InGe concentrated portion is in a state in which In oxide, Ge oxide, and an alloy of In and Ge are mixed.

The InGe concentrated portion does not contain oxides of In and Ge, and all In and Ge may be present in a metallic state. Further, the InGe concentrated portion may contain an In oxide, a Ge oxide, and an InGe composite oxide in an arbitrary ratio. Further, the InGe concentrated portion is entirely formed of the oxides of In and Ge even when the oxides of In and Ge are mixed in an arbitrary ratio with respect to the oxides of In and Ge in the metallic state. May be good.

Further, since the InGe concentrated portion is formed on the surface side of the Ag alloy film, the surface roughness (Ra) is lowered as compared with the case where the InGe concentrated portion is not formed, and the surface side of the Ag alloy film is further formed. It can be made smooth. By lowering the surface roughness (Ra) on the surface side of the Ag alloy film, the heat resistance and the sulfurization resistance of the Ag alloy film can be improved.

The surface roughness (Ra) of the surface of the Ag alloy film is, for example, 0.8 nm or less. When the surface roughness (Ra) is 0.8 nm or less, the effect of improving the heat resistance of the Ag alloy film can be kept high. In addition, it is possible to prevent a decrease in sulfurization resistance.

(Ag alloy sputtering target)
The Ag alloy sputtering target of the present invention may be any as long as it can form an Ag alloy film having the above-mentioned InGe concentrated portion by sputtering, and has a composition containing In and Ge and the balance being Ag and unavoidable impurities. It consists of Ag alloy.

Such an Ag alloy sputtering target can be obtained by the following procedure.
First, an Ag raw material having a purity of 99.99% by mass or more, an In raw material having a purity of 99.99% by mass or more, and a Ge raw material having a purity of 99.99% by mass or more are prepared.
When reducing the content of Pd, Pt, Au, and Rh contained in the Ag alloy, it is preferable to prepare an Ag raw material having a reduced content of these elements. In this embodiment, electrolytic refining was carried out on Ag having a purity of 99.9% by mass or more to prepare an electrodeposited Ag, and the obtained electrodeposited Ag was cast again as an anode for electrolysis and reelectrolysis was carried out. By repeating this, the contents of Pd, Pt, Au, and Rh in Ag were reduced. In addition, component analysis was performed by ICP emission spectroscopic analysis every time electrolytic refining was performed. As a result, the Pd content is 40 mass ppm or less, the Pt content is 20 mass ppm or less, the Au content is 20 mass ppm or less, the Rh content is 10 mass ppm or less, and Pd, Pt, and Au. It is possible to obtain an Ag raw material in which the total content of Rh and Rh is limited to 50 mass ppm or less.

Next, the above-mentioned Ag raw material, In raw material, and Ge raw material are weighed and charged into the container of the high-frequency vacuum melting furnace. Next, the inside of the vacuum chamber of the high-frequency vacuum melting furnace is evacuated, replaced with argon gas, and then Ag is melted. Then, in an argon gas atmosphere, In and Ge are added to the dissolved Ag, and the molten alloy is poured into a graphite mold and cast to prepare an ingot.

As a method of casting treatment, for example, a one-way solidification method can be used. In the one-way solidification method, for example, the molten metal is cast into a mold whose side surface is preheated by resistance heating while the bottom of the mold is water-cooled, and then the set temperature of the resistance heating part at the bottom of the mold is gradually lowered. It can be carried out by. As the method of casting, instead of the one-way solidification method described above, a method such as a complete continuous casting method or a semi-continuous casting method may be used.

The ingot is then hot forged to obtain a hot forged material. Here, the hot forging temperature is preferably in the range of 750 ° C. or higher and 850 ° C. or lower.
Next, the hot forged material described above is cold-rolled to obtain a cold-rolled material. The total reduction rate of cold rolling is preferably in the range of 60% or more and 70% or less.

Next, heat treatment is performed on the above-mentioned cold-rolled material. Here, the holding temperature during the heat treatment is set within the range of 350 ° C. or higher and 550 ° C. or lower.
By setting the holding temperature to 350 ° C. or higher, recrystallization proceeds, and the occurrence of cracks and abnormal discharge can be suppressed. On the other hand, by setting the holding temperature to 550 ° C. or lower, the particle size of the crystal grains can be made uniform and the occurrence of abnormal discharge can be suppressed.

The holding time at the holding temperature described above is preferably in the range of 1 hour or more and 2 hours or less. By setting the holding time at the holding temperature to 1 hour or more, recrystallization proceeds, and the occurrence of cracks and abnormal discharge can be suppressed. On the other hand, if the holding time at the holding temperature exceeds 2 hours, no further effect can be obtained.

By machining the heat-treated material obtained as described above, it is finished into a predetermined shape and dimensions. The Ag alloy sputtering target of the present embodiment can be manufactured by the above procedure.

(Manufacturing method of Ag alloy film)
When producing the Ag alloy film having the InGe concentrated portion of the present invention, the above-mentioned Ag alloy sputtering target is set in the target holder of the sputter film forming apparatus. Then, a substrate for film formation is attached, and an Ag alloy film is formed on the substrate.
An example of film formation conditions is shown below.
Film formation power density: 2.0 to 5.0 (W / cm ² )
Film formation gas: Ar
Film formation gas pressure: 0.2 to 0.4 (Pa)
Target-board distance: 60-80 (mm)

By performing sputtering under the above-mentioned conditions using the above-mentioned Ag alloy sputtering target, an InGe-concentrated portion in which In and Ge are concentrated is formed on the surface side of the Ag alloy film containing In and Ge. rice field. In and Ge of the InGe concentrated portion formed at this time are partially oxides.
Under the above-mentioned film forming conditions, when the film forming power density ^{exceeds 5.0 W / cm 2} , the concentration of In and Ge is less likely to occur on the surface side of the Ag alloy film, and the InGe concentrated portion is efficiently formed. It may not be formed.

Next, by heat-treating the formed Ag alloy film of the present embodiment, the oxidation of In and Ge in the InGe concentrated portion can be promoted. As a heat treatment condition, the Ag alloy film may be heated at 250 to 300 ° C. for about 1 to 2 hours in an atmosphere containing oxygen, for example. The atmosphere containing oxygen may be an atmosphere containing 2% or more of oxygen, for example, heating in air.
If the Ag alloy film is heat-treated to increase the concentration of In oxide and Ge oxide in the InGe concentrated portion, the In and Ge contained in Ag are concentrated, so that the Ag alloy film portion has a composition close to that of sterling silver. There are many parts. Therefore, the reflectance of the Ag alloy film can be increased. Further, the transmittance of the InGe concentrated portion increases when the concentration of the oxide state is higher than that of the state of In and Ge in the metallic state, so that the reflectance of the Ag alloy film can be increased.

In the Ag alloy film of the present embodiment having the above-described configuration, an InGe-concentrated portion in which In and Ge are concentrated is formed on the surface side, and the heat resistance is excellent.
Further, according to the Ag alloy sputtering target of the present embodiment, it is possible to form an Ag alloy film having excellent heat resistance by having an InGe concentrated portion where In and Ge are concentrated on the surface side.

In the present embodiment, the Ag alloy constituting the Ag alloy film contains 0.1% by mass or more and 1.5% by mass or less of In and 0.1% by mass or more and 7.5% by mass of Ge, and the balance is When it has a composition of Ag and unavoidable impurities, it is particularly excellent in heat resistance, and is particularly suitable for, for example, a reflective conductive film application.

Further, in the present embodiment, when the InGe concentrated portion contains oxides of In and Ge, the reflectance can be further improved.

Further, in the present embodiment, when the InGe concentrated portion is in the range of 0.5 nm or more and 10 nm or less in the film thickness direction from the surface of the Ag alloy film, the reflectance is lowered while maintaining the heat resistance. Can be prevented.

Further, in the present embodiment, when the surface roughness (Ra) of the surface of the Ag alloy film is 0.8 nm or less, it is possible to prevent a decrease in reflectance while maintaining heat resistance.

Further, in the present embodiment, the Ag alloy has a Pd content of 40 mass ppm or less, a Pt content of 20 mass ppm or less, an Au content of 20 mass ppm or less, and a Rh content of 10 mass ppm or less. Below, it is preferable that the total content of Pd, Pt, Au and Rh is 50 mass ppm or less.
Since Pd, Pt, Au, and Rh contained in the Ag alloy act as catalysts in the reduction reaction of nitric acid, if a large amount of these elements is contained, the etch great may increase when etched with a nitric acid etching solution. Therefore, by limiting the contents of Pd, Pt, Au, and Rh as described above, it is possible to keep the etching rate low even if the etching process is performed using an etching solution containing nitric acid.

Although the embodiments of the present invention have been described above, the present invention is not limited to this, and can be appropriately changed without departing from the technical idea of the invention.

The results of the confirmation experiment conducted to confirm the effectiveness of the present invention will be described below.

(Preparation of sample)
An Ag raw material having a purity of 99.99% by mass or more is prepared, the Ag raw material is melted in a vacuum atmosphere, the atmosphere is replaced with Ar gas, and then In and Ge having a purity of 99.99% by mass or more are added to obtain a predetermined value. The molten Ag alloy having the composition of the above was melted. Then, this molten Ag alloy was cast to produce an Ag alloy ingot. The Ag raw material reduced the contents of Pd, Pt, Au, and Rh, if necessary, as described in the column of the embodiment of the invention.

The obtained Ag alloy ingot was hot forged (temperature 800 ° C.) and then cold rolled (total rolling reduction 64%).
After that, the Ag alloy ingot was heat-treated with the holding temperature set to 450 ° C. and the holding time at the holding temperature set to 1.5 hours. Then, after the heat treatment, machining was carried out to produce a disk-shaped Ag alloy sputtering target having a diameter of 152.4 mm and a thickness of 6 mm.

Using the sputtering target produced by the above method, an Ag alloy film was formed under the following conditions.
Film formation power density: 2.0 to 5.0 (W / cm ² )
Film formation gas: Ar
Film formation gas pressure: 0.3 (Pa)
Distance between target and substrate: 70 (mm)
After discharging for 30 minutes under the above-mentioned film forming conditions (empty sputtering), film forming was performed to calculate the film forming rate. Then, an Ag alloy film having a film thickness of 100 nm was formed from the calculated film formation rate to obtain samples of Examples 1-16 of the present invention and Comparative Example 1-3.

(Ingredient composition)
Analytical samples were taken from each Ag alloy film, and the composition and noble metal elements were measured by ICP emission spectroscopic analysis. The measurement results are shown in Table 1 as the component composition of the Ag alloy film.

After that, with respect to the samples of Examples 1-16 of the present invention and Comparative Example 1-3, the presence or absence of the InGe concentrated portion before and after the heat treatment, the surface roughness (Ra), and the reflectance were measured. The heat treatment of the Ag alloy film was carried out in an air atmosphere at 250 ° C. for 1 h. Separately, a sulfurization test was performed without heat treatment, and the reflectance after the sulfurization test was also measured. Sulfide test Ag alloy film, 25 ° C., the concentration in air of the atmosphere in the humidity 75% (RH) is a mixture of hydrogen sulfide _(H 2 S) gas so that 3 ppm, 1h the Ag alloy film in this Exposed.

(Presence or absence of InGe concentrated part, thickness of InGe concentrated part, oxidation state of InGe concentrated part)
From the surface of the formed Ag alloy film to the substrate, analysis was performed using X-ray photomolecular spectroscopy (XPS), and the presence or absence of the InGe concentrated portion and the thickness of the InGe concentrated portion were calculated. Specifically, first, the etching rate (nm / scan) is calculated from the time (number of scans) for digging 100 nm Ag. Next, the peak intensity (count number / sec) of the peak positions of In and Ge at the number of scans that digs 50 nm, which is half of 100 nm, is confirmed. Then, the thickness up to the number of scans at which the peak intensities of In and Ge of 1.2 times or more of those peak intensities are obtained is regarded as the InGe concentrated portion where In and Ge are concentrated, and the thickness is Calculated by multiplying the number of scans described above by the etching rate. In addition, the oxidation state of the InGe concentrated part was confirmed by the position of each detection peak in the XPS depth analysis.

In practice, since In and Ge is the _In 2 _{O 3} and GeO ₂ is oxidized by atmospheric transfer and air heat treatment in until analysis by XPS was deposited, the _In 2 _{O 3} and GeO ₂ The presence or absence of the InGe concentrated portion may be determined by the change in peak intensity. Table 1 shows the presence or absence of InGe concentration and the thickness of the InGe concentration portion. Further, the oxidation state of the InGe concentrated portion is shown in FIGS. 1 (In) and 2 (Ge) as peak graphs of XPS depth analysis. The detection peak positions are as follows.
In ₂ O ₃ : 444.3 eV
In: 443.9eV
GeO ₂ : 32.5 eV
Ge: 29.3eV

(Surface roughness (Ra))
The surface roughness (Ra) of each Ag alloy film was calculated by scanning the surface of 1 μm square using an atomic force microscope (AFM: SPI3800N manufactured by Seiko Instruments Inc.). The measurement results are shown in Table 2.

(Reflectance)
The reflectance at 450 nm was measured on the surface of each Ag alloy film using a spectrophotometer (U-4100 manufactured by Hitachi High-Technologies Corporation). The measurement results are shown in Table 2.

(Etching characteristic evaluation)
First, a wiring pattern (wiring film) was formed by photolithography on an Ag alloy film having a thickness of 100 nm formed on a glass substrate.
Specifically, a photoresist agent (OFPR-8600 manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied on the formed Ag alloy film with a spin coater, exposed after prebaking at 110 ° C., and then a developing solution (Tokyo Ohka Kogyo Co., Ltd.) The pattern was developed by NMD-W manufactured by the company and post-baked at 150 ° C. As a result, a comb-shaped wiring pattern having a width of 100 μm and an interval of 100 μm was formed on the Ag alloy film.
Then, wet etching was performed on the above-mentioned Ag alloy film. SEA-2 manufactured by Kanto Chemical Co., Inc. was used as the etching solution, and etching was performed at a solution temperature of 40 ° C. and an immersion time of 30 seconds.

With respect to the wiring film obtained as described above, a substrate was cleaved to observe the wiring cross section, and the cross section was observed using an SEM (scanning electron microscope). Then, the difference between the parallel positions of the end of the Ag alloy film and the edge of the photoresist observed by SEM was measured as the amount of overetching of the Ag alloy film. The evaluation results are shown in Table 2.

According to the results in Tables 1 and 2, Examples 1-16 of the present invention in which the InGe concentrated portion was formed had a rough surface before and after the heat treatment as compared with Comparative Example 1-3 in which the InGe concentrated portion was not formed. It was found that the value of (Ra) was low.

Further, in Example 1-16 of the present invention, it was confirmed that the decrease in reflectance after heat treatment was small with respect to the reflectance before heat treatment. As a result, it was confirmed that Example 1-16 of the present invention is excellent in heat resistance because the reflectance does not significantly decrease even in a high temperature environment. On the other hand, in Comparative Examples 1-3, the reflectance after the heat treatment was significantly reduced as compared with that before the heat treatment, and the heat resistance was not sufficient.

In addition to this, from Example 2 of the present invention and Comparative Example 1, by including both In and Ge and setting the film formation power density to 5.0 W / cm ² or less, an InGe concentrated portion is generated in the Ag alloy film. Was confirmed.
Further, it was confirmed that the thickness of the InGe concentrated portion before the heat treatment became thinner as the film formation power density increased. It was also found that the higher the concentration of Ge, the thicker the thickness of the InGe concentrated portion.
Further, it was found that the reflectance before the heat treatment decreased as the concentrations of In and Ge increased. It was also found that the thickness of the InGe concentrated layer had almost no effect on the reflectance.
Further, regarding the reflectance after the heat treatment, it was found that when the concentrations of In and Ge increased, the decrease in the reflectance could be suppressed as compared with that before the heat treatment.
Regarding the reflectance after the sulfurization test, it was confirmed that as the concentration of In increased, the sulfurization resistance increased and the reflectance improved.

Further, the Pd content is 40 mass ppm or less, the Pt content is 20 mass ppm or less, the Au content is 20 mass ppm or less, the Rh content is 10 mass ppm or less, and Pd, Pt, and Au. In Example 1-11 of the present invention in which the total content of Rh was 50 mass ppm or less, the etching rate was kept relatively low.

In addition to the above-mentioned Examples 1-16 of the present invention and Comparative Example 1-3, when an Ag alloy film containing no In was formed and the reflectance after the sulfurization test was examined, the reflectance was significantly reduced (79). 8.8) Therefore, it was confirmed that the sulfurization resistance was improved by In.

Claims (6)

A Ag alloy film of Ag alloy containing In and Ge, and have a InGe concentration portion of In and Ge is the thickener on the surface side,
An Ag alloy film characterized in that In and Ge in the InGe concentrated portion are present as at least one or both of an oxide and a metal. The Ag alloy is characterized by containing 0.1% by mass or more and 1.5% by mass or less of In and 0.1% by mass or more and 7.5% by mass of Ge, and the balance is composed of Ag and unavoidable impurities. The Ag alloy film according to claim 1. The Ag alloy film according to claim 1 or 2, wherein the InGe concentrated portion contains oxides of In and Ge. The invention according to any one of claims 1 to 3, wherein the InGe concentrated portion is in a range of 0.5 nm or more and 10 nm or less in the film thickness direction from the surface of the Ag alloy film. Ag alloy film. The Ag alloy film according to any one of claims 1 to 4, wherein the surface roughness (Ra) of the surface of the Ag alloy film is 0.8 nm or less. The Ag alloy contains one or more selected from Pd, Pt, Au, and Rh, and has a Pd content of 40 mass ppm or less, a Pt content of 20 mass ppm or less, and Au. Claimed from claim 1, wherein the content is 20 mass ppm or less, the content of Rh is 10 mass ppm or less, and the total content of Pd, Pt, Au, and Rh is 50 mass ppm or less. Item 5. The Ag alloy film according to any one of Item 5.

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