JP2020041217A - Optical functional film, sputtering target, and method for manufacturing sputtering target - Google Patents

Abstract

To provide an optical functional film having durability and enabling light reflection from a metal thin film or the like to be sufficiently suppressed, and a sputtering target enabling the optical functional film to be effectively and stably deposited, and a method for manufacturing the sputtering target.SOLUTION: The optical functional film contains a first component comprising one or two or more selected from TiC, NbC, VC, TiN, NbN, and VN, a second component comprising one type or two or more s selected from InO, YO, NbO, VO, AlO, ZnO, and SiO, and has a film thickness d of 30 nm or more and 100 nm or less, a refractive index of 1.5 or more and 2.7 or less in a visible light region, and an extinction coefficient k of 0.3 or more and 1.5 or less in the visible light region.SELECTED DRAWING: None

Description

  The present invention relates to an optical functional film laminated on a metal thin film or the like to reduce reflection of light from the metal thin film or the like, a sputtering target used for forming the optical functional film, and a method of manufacturing the sputtering target It is about.

2. Description of the Related Art In recent years, a projection-type capacitive touch panel has been employed as an input unit of a portable terminal device or the like. In this type of touch panel, sensing electrodes are formed for touch position detection. This sensing electrode is usually formed by patterning, and an X electrode extending in the X direction and a Y electrode extending in the Y direction orthogonal to the X direction are formed on one surface of the transparent substrate. And these are arranged in a grid.
Here, when a metal film is used for the electrode of the touch panel, the pattern of the electrode is visually recognized from the outside because the metal film has a metallic luster. For this reason, it is conceivable that the visibility of the electrode is reduced by forming a low-reflectance film having a low visible light reflectance on the metal thin film.

In a flat panel display represented by a liquid crystal display device or a plasma display, a color filter for color display is employed. In this color filter, a black member called a black matrix is formed for the purpose of improving contrast and color purity and improving visibility.
The above-described low-reflectance film can also be used as this black matrix (hereinafter, referred to as “BM”).

Further, in a solar cell panel, when sunlight is incident through a glass substrate or the like, a back electrode of the solar cell is formed on the opposite side. As the back electrode, a metal film such as molybdenum (Mo) or silver (Ag) is used. When the solar cell panel of such an aspect is viewed from the back surface side, the metal film as the back surface electrode is visually recognized.
Therefore, it is conceivable that the visibility of the back electrode is reduced by forming the above-described low reflectance film on the back electrode.

Here, as the above-described low-reflectance film, for example, Patent Literature 1 discloses a black pigment having a black pigment made of carbon black or titanium nitride, a resin, a polymerization initiator, and an oxide for adjusting a refractive index. A membrane is disclosed.
Patent Documents 2 and 3 propose a sputtering target containing a carbide and an oxide as a sputtering target for forming an optical thin film.

JP-A-2017-212826 JP 2005-068507 A JP 2003-317771 A

  Here, in the low-reflection film described in Patent Document 1, a resin containing a black pigment made of carbon black or titanium nitride is formed in a film shape, and since the resin is a main component, durability is low. It was not enough.

The sputtering targets described in Patent Literatures 2 and 3 contain carbides, but since the carbides have a high melting point and poor sinterability, it has been difficult to sufficiently improve the density of the sintered body. . In a sputtering target having a low density, abnormal discharge frequently occurs during sputtering, and there is a possibility that a stable film cannot be formed.
Further, in the sputtering targets described in Patent Documents 2 and 3, since the conductivity is insufficient, a film cannot be stably formed by DC sputtering, and the film is formed by RF sputtering. Since the RF sputtering has a lower film forming efficiency than the DC sputtering, the optical functional film cannot be efficiently formed.

  Furthermore, the above-mentioned optical function film is required to have durability so that the optical characteristics do not change significantly during manufacturing and use. For example, when a heating step is performed after film formation, heat resistance is required. In the case where a wiring pattern is formed by etching, alkali is used when the resist film is stripped, and thus alkali resistance is required. In addition, water resistance is required because it comes into contact with water every time after cleaning after etching or alkali treatment.

  The present invention has been made in view of the above-mentioned circumstances, and has an optical function film having durability and capable of sufficiently suppressing reflection of light from a metal thin film or the like. It is an object of the present invention to provide a sputtering target capable of forming a stable film and a method for manufacturing the sputtering target.

In order to solve the above problems, the optical functional film of the present invention includes a first component composed of one or more selected from TiC, NbC, VC, TiN, NbN, and VN, and In ₂ O ₃ , Y ₂ A second component consisting of one or more selected from O ₃ , Nb ₂ O ₅ , V ₂ O ₅ , Al ₂ O ₃ , ZnO, and SiO ₂ , and having a thickness d of 30 nm or more and 100 nm or less , The refractive index n in the visible light region is in the range of 1.5 to 2.7, and the extinction coefficient k in the visible light region is in the range of 0.3 to 1.5. It is characterized by:

According to the optical functional film having this configuration, the durability of the film can be improved by one or more of the first components selected from TiC, NbC, VC, TiN, NbN, and VN, and The conductivity of the film can be ensured.
Further, by containing one or more of the second components selected from In ₂ O ₃ , Y ₂ O ₃ , Nb ₂ O ₅ , V ₂ O ₅ , Al ₂ O ₃ , ZnO, and SiO ₂ In addition, the optical characteristics of the film can be adjusted so as to further reduce the reflectance when the film is laminated on the metal wiring film. Note that the first component and the second component are not limited to those having the above stoichiometric ratio, and similar effects can be obtained even if carbon, nitrogen, and oxygen are partially deficient.

  In the optical functional film of the present invention, the film thickness d is in the range of 30 nm or more and 100 nm or less, the refractive index n in the visible light region is in the range of 1.5 or more and 2.7 or less, and the visible light region has Since the extinction coefficient k is in the range of 0.3 or more and 1.5 or less, the reflectance can be suppressed low, and the reflection of metal can be suppressed.

Here, in the optical functional film of the present invention, it is preferable that the specific resistivity is 5 Ω · cm or less.
In this case, the specific resistivity is 5 Ω · cm or less, and the conductivity is ensured, and it is possible to conduct electricity through this optical functional film.

Further, in the optical functional film of the present invention, the atomic ratio α / β of the total content α of C and N and the content β of O is preferably in the range of 0.01 or more and 5 or less.
In this case, since the atomic ratio α / β of the total content α of C and N and the content β of O is set to 0.01 or more, the durability of the film can be improved. On the other hand, since the atomic ratio α / β of the total content α of C and N and the content β of O is set to 5 or less, it is possible to maintain optical characteristics.

The sputtering target of the present invention includes a first component composed of one or more selected from TiC, NbC, VC, TiN, NbN, and VN, and In ₂ O ₃ , Y ₂ O ₃ , Nb ₂ O ₅ , V ₂ O ₅ , Al ₂ O ₃ , ZnO, and a second component composed of two or more selected from SiO ₂ .

According to the sputtering target having this configuration, the first component composed of one or more selected from TiC, NbC, VC, TiN, NbN, and VN, and In ₂ O ₃ , Y ₂ O ₃ , and Nb ₂ O ₅ , V ₂ O ₅ , Al ₂ O ₃ , ZnO, and a second component composed of two or more selected from SiO ₂ , so that the above-described optical functional film can be formed. . Note that the first component and the second component are not limited to those having the above stoichiometric ratio, and similar effects can be obtained even if carbon, nitrogen, and oxygen are partially deficient.

Here, in the sputtering target of the present invention, it is preferable that the density ratio is 90% or more and the specific resistivity is 0.1 Ω · cm or less.
In this case, since the density ratio is 90% or more, occurrence of abnormal discharge during sputtering can be suppressed, and a stable film can be formed. Furthermore, since the specific resistivity is 0.1 Ω · cm or less, the film can be stably formed by DC sputtering, and the optical function film can be efficiently formed.

Further, in the sputtering target of the present invention, it is preferable that the molar ratio A / B of the content A of the first component and the content B of the second component is in the range of 0.1 to 20.
In this case, since the molar ratio A / B of the content A of the first component and the content B of the second component is 0.1 or more and 20 or less, the optical functional film suppresses the reflectance of the base metal. A film having an optical constant suitable for the above can be obtained.

The method for manufacturing a sputtering target according to the present invention includes a first component powder composed of one or more selected from TiC, NbC, VC, TiN, NbN, and VN, and In ₂ O ₃ , Y ₂ O ₃ , and Nb _2. A powder mixing step of mixing one or two or more of the second component powders selected from O ₅ , V ₂ O ₅ , Al ₂ O ₃ , ZnO, and SiO ₂ , and sintering the mixed powders And in the powder mixing step, the first component powder has a particle diameter of 10 μm or more in a range of 3 vol% or more and 50 vol% or less, and the second component powder has a particle diameter of 10 μm or less. The following powder is characterized by being 70 vol% or more.

According to the method for manufacturing a sputtering target having this configuration, a first component powder composed of one or more selected from TiC, NbC, VC, TiN, NbN, and VN, and In ₂ O ₃ , Y ₂ O ₃ , A powder mixing step of mixing one or two or more second component powders selected from Nb ₂ O ₅ , V ₂ O ₅ , Al ₂ O ₃ , ZnO, and SiO ₂ , and sintering the mixed powders And the sintering step, so that the above-described sputtering target can be manufactured.
And, since the powder having a particle diameter of 10 μm or more is 3 vol% or more in the first component powder, the first component particles having conductivity in the sintered body are connected to each other, and the conductivity of the sputtering target is sufficiently improved. Can be secured.
In addition, the powder having a particle diameter of 10 μm or more is 50 vol% or less in the first component powder having poor sinterability, and the powder having a particle diameter of 10 μm or less is 70 vol% or more in the second component powder having excellent sinterability. Therefore, the density of the sintered body can be sufficiently improved.

  According to the present invention, an optical functional film having durability and capable of sufficiently suppressing reflection of light from a metal thin film or the like, a sputtering target capable of efficiently and stably forming the optical functional film, and Thus, a method for manufacturing this sputtering target can be provided.

FIG. 3 is an explanatory cross-sectional view of a laminated film including an optical function film according to an embodiment of the present invention. It is a flow figure showing the manufacturing method of the sputtering target concerning one embodiment of the present invention. It is an observation result of the structure of the sputtering target of Example 8 of the present invention. It is an observation result of the structure of the sputtering target of Example 29 of the present invention.

  Hereinafter, an optical functional film, a sputtering target, and a method for manufacturing a sputtering target, which are embodiments of the present invention, will be described with reference to the accompanying drawings.

As shown in FIG. 1, the optical function film 12 according to the present embodiment is formed so as to be laminated on the metal wiring film 11 formed on the surface of the substrate 1.
Here, the metal wiring film 11 is made of a metal having excellent conductivity, such as aluminum and an aluminum alloy, copper, or a copper alloy. In the present embodiment, the metal wiring film 11 is made of copper. Since this metal wiring film 11 has a metallic luster, it reflects visible light and is visually recognized from the outside.

The optical function film 12 according to the present embodiment is provided to suppress reflection of visible light on the stacked metal wiring films 11.
The optical functional film 12 according to the present embodiment includes a first component including one or more selected from TiC, NbC, VC, TiN, NbN, and VN, and In ₂ O ₃ , Y ₂ O ₃ , and Nb _2. And a second component composed of one or more selected from O ₅ , V ₂ O ₅ , Al ₂ O ₃ , ZnO, and SiO ₂ .

The first component composed of one or more selected from TiC, NbC, VC, TiN, NbN, and VN has conductivity, and the conductivity of the optical function film 12 is ensured by the first component. You. Further, the durability of the optical function film 12 is improved by the first component.
The second component composed of one or more selected from In ₂ O ₃ , Y ₂ O ₃ , Nb ₂ O ₅ , V ₂ O ₅ , Al ₂ O ₃ , ZnO and SiO ₂ is the first component described above. , The optical characteristics of the optical function film 12 can be adjusted.
Although the content ratio of the first component and the second component is appropriately set according to the optical characteristics of the optical functional film 12, the total content α of C and N derived from the first component and the second component It is preferable that the atomic ratio α / β of the content β of O originated in the range of 0.01 or more and 5 or less. When the atomic ratio α / β of the total content α of C and N and the content β of O is 0.01 or more, the durability of the film can be ensured. On the other hand, if the atomic ratio α / β of the total content α of C and N and the content β of O is 5 or less, the optical characteristics can be maintained, and an increase in reflectance and the like can be suppressed. Further, as long as this function is achieved, an optional element or compound may be further added as the third component.

The optical function film 12 according to the present embodiment has a thickness d in the range of 30 nm or more and 100 nm or less, a refractive index n in the visible light region of 1.5 or more and 2.7 or less, and in the visible light region. Has an extinction coefficient k of 0.3 or more and 1.5 or less. Here, the visible light is a wavelength in the range of 380 to 780 nm.
In the optical function film 12, reflection of the metal wiring film 11 is suppressed by absorption of visible light (extinction coefficient k) and interference (film thickness d and refractive index n). By adjusting the extinction coefficient k, reflection of all wavelengths of visible light is suppressed, and by adjusting the film thickness d and the refractive index n, the waveform and peak of the reflected light are suppressed.

Here, in the present embodiment, the lower limit of the thickness d of the optical function film 12 is preferably 35 nm or more, and more preferably 40 nm or more. The upper limit of the thickness d of the optical function film 12 is preferably 85 nm or less, more preferably 70 nm or less.
The lower limit of the refractive index n in the visible light region is preferably 1.8 or more, and more preferably 2.0 or more. The upper limit of the refractive index n in the visible light region is preferably 2.6 or less, more preferably 2.5 or less.
Further, the lower limit of the extinction coefficient k in the visible light region is preferably 0.4 or more, more preferably 0.5 or more. The upper limit of the extinction coefficient k in the visible light region is preferably 1.4 or less, more preferably 1.3 or less.

Here, in the optical function film 12 according to the present embodiment, the product of the film thickness d, the refractive index n in the visible light region (wavelength 550 nm) and the extinction coefficient k in the visible light region (wavelength 550 nm), d × n It is preferable that xk be in the range of 30 or more and 150 or less. By setting d × n × k within the above range, it is possible to more reliably suppress the reflection in the visible light region due to absorption and interference of visible light.
The lower limit of d × n × k is preferably 40 or more, and more preferably 50 or more. The upper limit of d × n × k is preferably 130 or less, and more preferably 110 or less.

Further, it is preferable that the optical functional film 12 of the present embodiment has a specific resistivity of 5 Ω · cm or less. Thereby, it is possible to conduct the metal wiring film 11 and the external wiring via the optical function film 12. If the specific resistivity exceeds 5Ω · cm, conduction with the external wiring can be achieved by forming a hole in the low-reflection film or the substrate to conduct the metal wiring with the outside.
The specific resistivity is preferably 1 Ω · cm or less, more preferably 0.1 Ω · cm or less.

  Next, the sputtering target according to the present embodiment will be described. The sputtering target according to the present embodiment is used for forming the optical function film 12 described above.

The sputtering target according to the present embodiment includes a first component including one or more selected from TiC, NbC, VC, TiN, NbN, and VN, and In ₂ O ₃ , Y ₂ O ₃ , and Nb ₂ O _5. , V ₂ O ₅ , Al ₂ O ₃ , ZnO, and a second component composed of two or more kinds selected from SiO ₂ .

The first component composed of one or more selected from TiC, NbC, VC, TiN, NbN, and VN has conductivity, and the first component causes conductivity of the sputtering target according to the present embodiment. Nature is secured.
The second component composed of one or more selected from In ₂ O ₃ , Y ₂ O ₃ , Nb ₂ O ₅ , V ₂ O ₅ , Al ₂ O ₃ , ZnO, and SiO ₂ is compared with the first component. As a result, the density of the sputtering target of the present embodiment is improved.
Note that the content ratio of the first component and the second component is appropriately set according to the optical characteristics of the optical functional film 12 to be formed. For example, the content A of the first component and the content of the second component The molar ratio A / B of the content B is preferably in the range of 0.1 or more and 20 or less, more preferably 10 or less.

Here, the structure of the sputtering target according to the present embodiment changes depending on the content ratio of the first component and the second component. In the present embodiment, In ₂ O ₃ , Y ₂ O ₃ , and Nb _{2 are used. O 5, V 2 O 5,} Al 2 O 3, ZnO, a second component comprising one or more selected from _{SiO 2, TiC, NbC, VC} , TiN, NbN, one selected from VN or It is a structure in which two or more first components are dispersed.

And, in the sputtering target of the present embodiment, the density ratio is set to 90% or more. By setting the density ratio to 90% or more, it is possible to suppress occurrence of abnormal discharge during sputtering.
Here, in the sputtering target of the present embodiment, the density ratio is preferably at least 92%, more preferably at least 93%.

In the sputtering target according to the present embodiment, the specific resistivity is set to 0.1 Ω · cm or less. By setting the specific resistivity to 0.1 Ω · cm or less, a film can be formed by DC sputtering.
Here, in the sputtering target according to the present embodiment, the specific resistivity is preferably 5 × 10 ⁻² Ω · cm or less, more preferably 1 × 10 ⁻² Ω · cm or less.

  Next, a method for manufacturing a sputtering target according to this embodiment will be described with reference to FIG.

In the present embodiment, as shown in FIG. 2, a first component powder of one or more selected from TiC, NbC, VC, TiN, NbN, and VN, and In ₂ O ₃ and Y ₂ O ₃ , Nb ₂ O ₅ , V ₂ O ₅ , Al ₂ O ₃ , ZnO, SiO ₂ , a second component powder of one or more selected from two or more, a powder mixing step S 01, and the obtained mixing A sintering step S02 for sintering the powder and a machining step S03 for machining the obtained sintered body are provided.

(Powder mixing step S01)
In the powder mixing step S01, the content of the powder having a particle diameter of 10 μm or more is 3 vol% or more and 50 vol or more for the first component powder composed of one or more selected from TiC, NbC, VC, TiN, NbN and VN. % Or less. The second component powder composed of one or more selected from In ₂ O ₃ , Y ₂ O ₃ , Nb ₂ O ₅ , V ₂ O ₅ , Al ₂ O ₃ , ZnO, and SiO ₂ has particles The content of the powder having a diameter of 10 μm or less is set to 70 vol% or more.

Here, in the case where the content of the powder having a particle diameter of 10 μm or more is less than 3 vol%, the first component may not be able to sufficiently secure conductivity by the first component. On the other hand, when the content of the powder having a particle diameter of 10 μm or more exceeds 50 vol%, the sinterability may be insufficient and the density may not be sufficiently improved.
From the above, in the present embodiment, the content of the powder having a particle diameter of 10 μm or more in the first component powder is in the range of 3 vol% or more and 50 vol% or less.
The lower limit of the content of the powder having a particle diameter of 10 μm or more in the first component powder is preferably 10 vol% or more, and more preferably 20 vol% or more. On the other hand, the upper limit of the content of the powder having a particle diameter of 10 μm or more is preferably 45 vol% or less, and more preferably 40 vol% or less.

When the content of the second component powder having a particle diameter of 10 μm or less is less than 70 vol%, sinterability cannot be ensured, and the density may not be sufficiently improved. Was.
From the above, in the present embodiment, the content of the powder having a particle diameter of 10 μm or less is set to 70 vol% or more in the second component powder.
In addition, regarding the second component powder, the lower limit of the powder having a particle diameter of 10 μm or less is preferably 75 vol% or more, and more preferably 80 vol% or more.
The sintering raw material powder is obtained by mixing the first component powder and the second component powder.

(Sintering step S02)
Next, the above-mentioned sintering raw material powder is sintered by heating while applying pressure to obtain a sintered body. In this embodiment, sintering was performed using a hot press device or a hot isostatic pressing device (HIP).
The sintering temperature in this sintering step S02 is in the range of 800 ° C. or more and 1800 ° C. or less, the holding time at the sintering temperature is in the range of 1 hour or more and 15 hours or less, and the pressing pressure is in the range of 10 MPa or more and 200 MPa or less. did.

(Machining process S03)
Next, the obtained sintered body is machined so as to have a predetermined size. Thus, the sputtering target according to the present embodiment is manufactured.

According to the optical function film 12 of the present embodiment having the above-described configuration, the film is formed by a first component selected from one or more selected from TiC, NbC, VC, TiN, NbN, and VN. The durability can be improved, and the conductivity of the film can be ensured.
Further, by containing one or more of the second components selected from In ₂ O ₃ , Y ₂ O ₃ , Nb ₂ O ₅ , V ₂ O ₅ , Al ₂ O ₃ , ZnO, and SiO ₂ In addition, the optical characteristics of the film can be adjusted.

In the optical function film 12 according to the present embodiment, the thickness d is in the range of 30 nm to 100 nm, the refractive index n in the visible light region is in the range of 1.5 to 2.7, and Since the extinction coefficient k of the region is in the range of 0.3 or more and 1.5 or less, the reflectance can be kept low, and the metal reflection of the metal wiring film 11 can be suppressed. Visual recognition can be suppressed.
Furthermore, since the specific resistivity is set to 5 Ω · cm or less, conductivity is ensured, and it is possible to conduct electricity through the optical function film 12.

Further, according to the sputtering target of the present embodiment, the first component composed of one or more selected from TiC, NbC, VC, TiN, NbN, and VN, and In ₂ O ₃ , Y ₂ O ₃ , The above-mentioned optical function film 12 is formed because it contains one or two or more kinds of components selected from Nb ₂ O ₅ , V ₂ O ₅ , Al ₂ O ₃ , ZnO and SiO _2. Can be membrane.
Further, since the density ratio is 90% or more, occurrence of abnormal discharge during sputtering can be suppressed, and a stable film can be formed.
Further, since the specific resistivity is 0.1 Ω · cm or less, the film can be stably formed by DC sputtering, and the above-described optical function film 12 can be efficiently formed.

Further, according to the method for manufacturing a sputtering target of the present embodiment, the first component powder of one or more selected from TiC, NbC, VC, TiN, NbN, and VN, and In ₂ O ₃ , Y A powder mixing step of mixing one or two or more second component powders selected from ₂ O ₃ , Nb ₂ O ₅ , V ₂ O ₅ , Al ₂ O ₃ , ZnO, and SiO ₂ , and S01; Since the method includes the sintering step S02 for sintering the powder, the above-described sputtering target can be manufactured.

And, since the powder having a particle diameter of 10 μm or more is 3 vol% or more in the first component powder, the first component particles having conductivity in the sintered body are connected to each other, and the conductivity of the sputtering target is sufficiently ensured. can do.
In addition, the powder having a particle diameter of 10 μm or more is 50 vol% or less in the first component powder having poor sinterability, and the powder having a particle diameter of 10 μm or less is 70 vol% or more in the second component powder having excellent sinterability. Therefore, the density of the sintered body can be sufficiently improved.

As described above, the embodiments of the present invention have been described, but the present invention is not limited thereto, and can be appropriately changed without departing from the technical idea of the present invention.
For example, in the present embodiment, the laminated film having the structure shown in FIG. 1 has been described as an example. However, the present invention is not limited to this, and it is a laminated film having a structure of glass substrate / optical function film / metal wiring. You may. In this case, light from the glass substrate is reflected. With this structure, the optical function film does not need to have conductivity.

  Hereinafter, the results of an evaluation test for evaluating the effects of the optical functional film, the sputtering target, and the method for manufacturing a sputtering target according to the present invention will be described.

In order to produce a sputtering target, a first component powder (TiC powder, NbC powder, VC powder, TiN powder, NbN powder, VN powder) having a particle diameter described in Tables 1 to 3 and having a purity of 99 mass% or more, and A second component powder (In ₂ O ₃ powder, Y ₂ O ₃ powder, Nb ₂ O ₅ powder, V ₂ O ₅ powder, Al ₂ O ₃ powder, ZnO powder, SiO ₂ powder) is prepared, and a desired target composition is prepared. 2 kg of each powder weighed so as to have a ratio was filled in a 10 L pot, and 6 kg of a ball having a diameter of 5 mm was charged, followed by mixing with a ball mill.
Tables 1 to 3 show the molar ratio A / B of the content A of the first component and the content B of the second component. Comparative Examples 1 to 3 which did not contain the second component were "-", and Comparative Example 4 which did not contain the first component and contained only the second component was "0".

Using the above-mentioned mixed powder, sintering was performed under the conditions shown in Tables 4 to 6 to obtain a sintered body.
About the example of a hot press, the mixed powder is filled into a hot press mold (φ135 mm) made of carbon, and hot pressed in a vacuum at the temperature and pressure described in the examples for 3 hours to obtain a sintered body. Produced.
Regarding the example of HIP, first, the mixed powder was filled in a rubber mold having a diameter of 225 mm, and press-molded with a cold isostatic pressure (CIP) device at 150 MPa for 5 minutes to produce a molded body. Thereafter, the molded body was set in a SPCC (rolled steel) can, and after welding the SPCC, the vacuum was evacuated to 0.001 Pa or less, the can was sealed, and sintering was performed at the temperature and pressure described in the examples for 2 hours. A sintered body was produced.

These sintered bodies were machined to have a diameter of 125 mm and a thickness of 5 mm, and then were attached to a Cu backing plate with In solder to produce a sputtering target. When it is desired to reduce impurity elements, it is preferable to use raw material powder having higher purity. In addition, the In ₂ O ₃ powder and the ZnO powder may be reduced during hot pressing and HIP to precipitate In and Zn, respectively, so that the carbon type, the In ₂ O ₃ powder, and the ZnO powder do not directly touch. Preferably, boron nitride is sufficiently applied to the carbon mold.

The particle diameters of the first component powder and the second component powder were measured as follows.
100 mL of an aqueous solution having a sodium hexametaphosphate concentration of 0.2 vol% was prepared, and 10 mg of each raw material powder was added to the aqueous solution. Standard) was measured.
From the obtained particle size distribution (volume basis), the ratio of the volume of the powder of 10 μm or more for the first component powder and the ratio of the volume of the powder of 10 μm or less for the second component powder were obtained.

  The following items were evaluated for the obtained sputtering target and the optical functional film formed using the sputtering target as described above.

(Density ratio of sputtering target)
The volume of the sputtering target was calculated from the dimensions of the obtained processed sputtering target, and the dimensional density of the sputtering target was calculated by dividing the measured weight value by the volume. The ratio obtained by dividing the dimensional density by the calculated density is shown in the table as “density ratio”. The calculated density was calculated according to the following equation. The evaluation results are shown in Tables 4 to 6.
Calculated density (g / cm ³ ) = 100 / {first component charge (mass%) / first component density (g / cm ³ ) + second component charge (mass%) / second component density (g / cm 2) cm ³ )｝

(Structure of sputtering target)
An observation sample was collected from the obtained sputtering target, embedded in an epoxy resin, polished, and then subjected to a 3000 × magnification using an electron probe microanalyzer (EPMA) device in a range of 36 μm × 28 μm. Element mapping was performed.
From the mapping image of the metal contained in the first component and the mapping image of the metal contained in the second component, the tissue composition of the first component and the second component was observed.
When an arbitrary line segment crossing the obtained image is drawn, when both the region of the first component and the region of the second component are crossed, it is considered that the tissue has the first component uniformly dispersed in the matrix of the second component. Judgment was made and "Y" was given. The structure of a single component in the comparative example is indicated by "-". The evaluation results are shown in Tables 4 to 6.
FIG. 3 shows the observation result of the present invention example 8, and FIG. 4 shows the observation result of the present invention example 29.

(Specific resistance of sputtering target)
Using a low resistivity meter (Loresta-GP) manufactured by Mitsubishi Chemical Corporation with respect to the center of the sputtering surface of the obtained sputtering target, values measured by a four-point probe method are shown in the table. The measurement was performed at a temperature of 23 ± 5 ° C. and a humidity of 50 ± 20%. Note that an ASP probe was used as a probe at the time of measurement. When the measured value was not measured, it was described as OR (OverRange). The evaluation results are shown in Tables 4 to 6.

(Abnormal discharge measurement)
The number of abnormal discharges when sputtering was performed for 1 hour under the following conditions using the obtained sputtering target is shown in the table. It was determined that DC sputtering was not possible for the sputtering target for which no discharge occurred. The evaluation results are shown in Tables 4 to 6.
Power supply: DC power supply (mks RPG-50)
Power: 615W
Gas pressure: 0.67 Pa
Gas flow rate: Ar 50 sccm

(Single film evaluation)
In the obtained sputtering target, a film having a thickness of 50 nm was formed on a 20 mm square Si substrate for DC sputtering that was performed stably. If the DC sputtering was not performed stably, it was determined that the film could not be formed. The film thickness at this time was controlled by forming a film during a film formation time to reach a target film thickness (50 nm) using the film deposition rate calculated in advance. With respect to the obtained film, the following evaluations (1) to (3) were performed.

(1) Analysis of film composition Each metal component and C, O, and N components were quantified by quantitative analysis using an EPMA apparatus. From the obtained results, the ratio of each component when the total value of the detected metal component and the C, O, and N components was set to 100% was calculated, and is shown in Tables 7 to 9. At this time, the O component was described as the balance.

From the depth profile analysis of the XPS apparatus, the peaks identified as TiC, NbC, VC, TiN, NbN, and VN, respectively, were found from the profiles of the metal components TiC, NbC, VC, TiN, NbN, and VN added as the first component. It was confirmed that it could be obtained. Further _In 2 _O 3 was added as the second _{component, Y 2 O 3, Nb 2} O 5, V 2 O 5, Al 2 O 3, ZnO, also in SiO _2, from the profile of the metal components, respectively _In 2 _{O 3} , Y ₂ O ₃ , Nb ₂ O ₅ , V ₂ O ₅ , Al ₂ O ₃ , ZnO, and SiO ₂ were confirmed to be obtained.

(2) Measurement of refractive index and extinction coefficient The refractive index and the extinction coefficient were calculated using UVISEL-HR320 (spectroscopic ellipsometry manufactured by Horiba, Ltd.). Tables 7 to 9 show values at a wavelength of 550 nm from the obtained refractive index and extinction coefficient. Tables 7 to 9 also show values calculated for the product (n × k × d) of the refractive index, the extinction coefficient, and the thickness of the optical functional film when the black film is formed (when the laminated film is formed). The thickness of the optical functional film at the time of forming the black film (at the time of forming the laminated film) is the thickness of the optical functional film formed by the reflectance measurement described later, and the film thickness d described in Tables 7 to 9 is used. Was.

(3) Measurement of Specific Resistance Tables 7 to 9 show values measured by a four-probe method using Loresta-GP (manufactured by Mitsubishi Chemical Analytic). The measurement was performed at a temperature of 23 ± 5 ° C. and a humidity of 50 ± 20%. Note that a PSP probe was used as a probe during measurement.

(Reflectance measurement)
A 200 nm thick Cu film was formed on a glass substrate. Further, a 20-nm-thick Mo film / 100-nm-thick Al film / 20-nm-thick Mo film (MAM film) were formed on a glass substrate.
Then, the above-mentioned optical function film was formed on the Cu film and the MAM film so as to have a film thickness d shown in Tables 7 to 9, respectively, to form a laminated film. Next, the reflectance of the laminated film formed on the glass substrate as described above was measured. In this measurement, a spectrophotometer (U4100 manufactured by Hitachi) was used to measure at a wavelength of 380 to 780 nm from the side of the formed film. The average values of the obtained reflectance data are shown in Tables 10 to 12.

(Heat resistance test)
The laminated film manufactured by the reflectance measurement was heated at 400 ° C. in a nitrogen atmosphere for 30 minutes. The reflectance after the treatment was measured in the same manner as immediately after the film formation. The evaluation results are shown in Tables 10 to 12.

(Alkali resistance test)
The laminated film produced by the reflectance measurement was immersed in a 3 mass% NaOH aqueous solution at room temperature for 30 minutes. The reflectance after the treatment was measured in the same manner as immediately after the film formation. The evaluation results are shown in Tables 10 to 12.

(Immersion test)
The laminated film produced by the reflectance measurement was immersed in pure water at 40 ° C. for 30 minutes. The reflectance after the treatment was measured in the same manner as immediately after the film formation. The evaluation results are shown in Tables 10 to 12.

  In Comparative Example 1, which did not contain the first component and the second component and was composed of copper oxide, the density ratio of the sputtering target was low at 88.2%, and the number of abnormal discharges was relatively high at 11 times. . Further, in the film formed by this sputtering target, the reflectance changed significantly after the alkali resistance test, and the film was poor in alkali resistance.

In Comparative Example 2 containing NbC as the first component but not containing the second component, the density ratio of the sputtering target was as low as 49.1%. In the film formed by this sputtering target, the reflectance of the formed film was high.
In Comparative Example 3 containing VC as the first component but not containing the second component, the density ratio of the sputtering target was as low as 78.2%. In the film formed by this sputtering target, the reflectance of the formed film was high.

In Comparative Example 4, which contained the second component Y ₂ O ₃ but did not contain the first component, the specific resistance was too high to measure. For this reason, a film could not be formed by DC sputtering.

On the other hand, the first component powder contains the first component and the second component, and the content of the powder of 10 μm or more is in the range of 5 vol% to 50 vol%, and the second component powder has the content of 10 μm or less. In the examples of the present invention in which the content of the powder was 70 vol% or more, the density ratio was as high as 90% or more, and the specific resistivity was 0.1 Ω · cm or less. Therefore, occurrence of abnormal discharge was suppressed, and a film could be stably formed by DC sputtering. Furthermore, as a result of observation of the structure of the sputtering target, it was confirmed that the second component had a structure in which the first component was uniformly dispersed.
Further, the formed optical functional film had a specific resistivity of 5 Ω · cm or less, and was excellent in conductivity. Further, the reflectance after film formation was low, and the reflection of the metal wiring film could be suppressed. Furthermore, even after the heat resistance test, the alkali resistance test, and the water immersion test, the reflectance did not change significantly, and the durability was excellent.

  From the above, according to the example of the present invention, an optical functional film having durability and conductivity and capable of sufficiently suppressing the reflection of light from a metal thin film or the like, efficiently stabilizing this optical functional film It has been confirmed that a sputtering target capable of forming a film by sputtering and a method for manufacturing the sputtering target can be provided.

12 Optical function film

Claims (7)

TiC, NbC, VC, TiN, NbN, and one or a first component consisting of two or more selected from _{VN, In 2 O 3, Y} 2 O 3, Nb 2 O 5, V 2 O 5, Al 2 O ₃ , one or two or more second components selected from ZnO and SiO ₂ ,
The film thickness d is in the range of 30 nm to 100 nm, the refractive index n in the visible light region is in the range of 1.5 to 2.7, and the extinction coefficient k in the visible light region is 0.3 to 1.5. An optical functional film having the following range.   The optical functional film according to claim 1, wherein the specific resistance is 5 Ω · cm or less.   The optical functional film according to claim 1, wherein an atomic ratio α / β of a total content α of C and N and a content β of O is in a range of 0.01 or more and 5 or less. 4. TiC, NbC, VC, TiN, NbN, and one or a first component consisting of two or more selected from _{VN, In 2 O 3, Y} 2 O 3, Nb 2 O 5, V 2 O 5, Al 2 O _3, ZnO, sputtering target characterized by containing a second component consisting of one or more selected from SiO _2, the.   The sputtering target according to claim 4, wherein the density ratio is 90% or more and the specific resistivity is 0.1 Ω · cm or less.   The sputtering target according to claim 4, wherein a molar ratio A / B of the content A of the first component and the content B of the second component is in a range of 0.1 to 20. 7. TiC, NbC, VC, TiN, NbN, and one or the first component powder consisting of two or more selected from _{VN, In 2 O 3, Y} 2 O 3, Nb 2 O 5, V 2 O 5, Al 2 A powder mixing step of mixing one or two or more second component powders selected from O ₃ , ZnO, and SiO ₂ , and a sintering step of sintering the mixed powder;
In the powder mixing step, the first component powder has a content of powder having a particle diameter of 10 μm or more in a range of 3 vol% or more and 50 vol% or less,
The method for producing a sputtering target, wherein the content of the second component powder having a particle diameter of 10 μm or less is 70% or more.