KR102237332B1 - Sputtering target - Google Patents

Abstract

It has a metallic copper phase and a copper oxide phase, and the volume ratio of a copper oxide phase exceeds 80 vol% and is in a range of 90 vol% or less, and the deviation from the average value of the specific resistance value on a target sputtering surface is 50% or less. And the particle diameter of the metallic copper phase in the target structure is in a range of 10 µm or more and 200 µm or less. Moreover, it is preferable to have the property of a p-type semiconductor.

Description

Sputtering target

The present invention relates to a sputtering target used when forming a copper oxide film.

This application claims priority based on Japanese Patent Application No. 2016-057461 filed in Japan on March 22, 2016 and Japanese Patent Application No. 2017-038734 filed in Japan on March 1, 2017, and its contents Is used here.

In general, as a conductive film used for a touch sensor or the like, it is known to have a transparent conductor layer formed on both surfaces of the film and a metal layer formed on the surface of each transparent conductor layer.

Here, in the above-described conductive film, there is a problem that adjacent conductive films adhere to each other when wound in a roll shape, and scratches occur in the transparent conductor layer when the adhered conductive film is peeled off.

Therefore, in Patent Document 1, a film in which an inorganic nanocoating layer is formed on a film substrate is proposed. In this film, it becomes possible to suppress adhesion between adjacent films by the inorganic nanocoating layer. Moreover, as this inorganic nanocoating layer, a copper oxide film can be applied.

As a method of forming a copper oxide film on the surface of a substrate such as a film, for example, sputtering is performed using a copper oxide target or sputtering (reactive sputtering) in the presence of oxygen gas using an oxygen-free copper target. A method of implementation is disclosed.

For example, in Patent Document 2, an oxygen-containing copper target for forming an oxygen-containing copper film is proposed.

In addition, in Patent Document 3, a sputtering target made of a _{Cu/Cu 2 O composite alloy is disclosed.}

Japanese Patent Publication No. 2014-529516 (A) Japanese Patent Application Laid-Open No. 2008-280545 (A) Japanese Unexamined Patent Application Publication No. 2001-210641 (A)

By the way, when sputtering is performed in the presence of oxygen gas using an oxygen-free copper target, the reaction between copper and oxygen cannot be sufficiently controlled, and it has been difficult to form a uniform copper oxide film.

Moreover, when a copper oxide target is used, since the resistance of the target itself is very high and DC (direct current) sputtering is difficult, RF (high frequency) sputtering is usually performed.

In this RF (high frequency) sputtering, there is a problem that the film forming speed is slow and productivity is lowered.

In addition, in the oxygen-containing copper target described in Patent Document 2, since the oxygen content was small, the formed oxygen-containing copper film had the same characteristics as that of the metallic copper film, and the characteristics as a copper oxide film were insufficient.

In addition, Patent Document 3 describes that processing becomes difficult when the blending ratio of _{Cu 2 O exceeds 80 vol%.} In addition, _{it is described that when the mixing ratio of Cu 2} O increases, the resistance value of the formed wiring film increases. For this reason, in Patent Document 3, _{the blending ratio of Cu 2} O is limited to 80 vol% or less.

In addition, as described in Patent Document 3, _{when the content of Cu 2} O is 80 vol% or less and the content of metal Cu is high, the metal Cu phase exists in the form of a network, and conductivity is ensured. In the sputtering target having such a configuration, a copper oxide phase having a lower conductivity than that of metallic Cu causes abnormal discharge, and there is a fear that sputtering cannot be stably performed.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sputtering target capable of DC sputtering and capable of forming a uniform copper oxide film.

In order to solve the above problems, the sputtering target of one aspect of the present invention (hereinafter, referred to as "sputtering target of the present invention") has a metallic copper phase and a copper oxide phase, and the volume ratio of the copper oxide phase is 80 vol%. It exceeds and falls within the range of 90 vol% or less, the deviation from the average value of the resistance value on the target sputtering surface is 50% or less, and the average particle diameter of the metallic copper phase in the target structure is 10 µm or more and 200 µm or less. It is characterized by being inside.

According to the sputtering target of the present invention, since the volume ratio of the copper oxide phase exceeds 80 vol%, the copper oxide phase is sufficiently present, and a copper oxide film can be formed without sputtering in the presence of oxygen gas.

Further, since the volume ratio of the copper oxide phase is in the range of 90 vol% or less, and the particle diameter of the metallic copper phase in the target structure is in the range of 10 µm or more and 200 µm or less, the relatively fine metallic copper phase is uniformly dispersed. And since the deviation of the average value of the resistance value on the target sputtering surface is 50% or less, and the variation of the resistance value of the target sputtering surface is small, conductivity is sufficiently secured as a whole of the target. Therefore, it becomes possible to stably form a copper oxide film by DC sputtering.

Here, in the sputtering target of the present invention, it is preferable that the target has the properties of a p-type semiconductor as a whole.

In this case, the metallic copper phase is dispersed in an island phase, and the copper oxide phase present between these metallic copper phases contributes to the conduction of the target as a p-type semiconductor, thereby having the properties of a p-type semiconductor as a whole, and improving conductivity. I think it can be secured. Thereby, the copper oxide phase does not cause abnormal discharge, and it becomes possible to form a copper oxide film by DC sputtering.

On the other hand, when the metallic Cu phase exists in the form of a network and conductivity is ensured, the target does not have the properties of a semiconductor as a whole. In the sputtering target having such a configuration, a copper oxide phase having a lower conductivity than that of metallic Cu causes abnormal discharge, and there is a fear that sputtering cannot be stably performed.

In addition, in the sputtering target of the present invention, it is preferable that the resistance value is 10 Ω·cm or less.

In this case, since the resistance value of the target is kept sufficiently low, DC sputtering can be reliably performed.

In addition, in the sputtering target of the present invention, as a result of X-ray diffraction analysis, _{the ratio I1/I2 of the diffraction intensity I1 of CuO and the diffraction intensity I2 of Cu 2} O is preferably 0.15 or less.

In this case, the presence ratio of CuO in the copper oxide phase is small, and the presence ratio of _{Cu 2 O is high.}

Here, since CuO reacts with metallic copper _{to generate Cu 2} O, when the presence ratio of CuO is high, metallic copper and CuO become not fully reacted. For this reason, when the presence ratio of CuO in the copper oxide phase is 0.15 or less, Cu ₂ O is uniformly dispersed, and variations in resistance values in the target can be suppressed.

In addition, in the sputtering target of the present invention, as a result of X-ray photoelectron spectroscopy analysis, _{the ratio IP1/IP2 of the peak intensity IP1 of CuO and the peak intensity IP2 of Cu and Cu 2} O is in the range of 0.03 or more and 0.4 or less. It is desirable.

In this case, since the ratio IP1/IP2 of the peak intensity IP1 of CuO and _{the peak intensity IP2 of Cu and Cu 2} O is 0.03 or more, and CuO is present in the copper oxide phase, the strength of the sintered body is improved. It is possible to suppress the occurrence of cracks. On the other hand, since IP1/IP2 is 0.4 or less, the presence ratio of CuO in the copper oxide phase decreases, and variations in resistance values in the target can be suppressed.

In addition, in the sputtering target of the present invention, it is preferable that the density is in the range of 5.5 g/cm 3 or more and 7.5 g/cm 3 or less.

In this case, since the density is 5.5 g/cm 3 or more, voids existing on the target sputtering surface can be reduced, and occurrence of abnormal discharge during sputtering can be suppressed. Moreover, since the density is 7.5 g/cm 3 or less, workability is improved, and the sputtering target is easily molded.

According to the present invention, it is possible to provide a sputtering target capable of DC sputtering and forming a uniform copper oxide film.

1 is an explanatory view showing a measurement position of a resistance value on a target sputtering surface of a sputtering target in which a target shape is a flat plate and a target sputtering surface is circular.
Fig. 2 is an explanatory diagram showing a measurement position of a resistance value on a target sputtering surface of a sputtering target in which the target shape is a flat plate and the target sputtering surface is a square.
Fig. 3 is an explanatory view showing a measurement position of a resistance value on a target sputtering surface of a sputtering target whose target shape is a cylinder and the target sputtering surface is a cylindrical outer circumferential surface.
4 is a diagram showing an example of XRD results in Inventive Example 2 and Comparative Example 1. FIG.
5 is a diagram showing an example of XPS results in Example 16 of the present invention.

Hereinafter, a sputtering target which is an embodiment of the present invention will be described. In addition, the sputtering target according to the present embodiment is used when forming a copper oxide film.

The sputtering target according to the present embodiment has a metallic copper phase and a copper oxide phase, and the volume ratio of the copper oxide phase exceeds 80 vol% and falls within a range of 90 vol% or less. In addition, in this embodiment, the content of Cu is in the range of 70 atomic% or more and 74 atomic% or less.

The metallic copper phase is dispersed in the target in an island phase, and the average particle diameter of the metallic copper phase is in the range of 10 µm or more and 200 µm or less.

In addition, in the sputtering target according to the present embodiment, the deviation from the average value of the resistance value on the target sputtering surface is 50% or less.

The copper oxide phase _{mainly has Cu 2} O, and CuO may exist in a part. Here, in the sputtering target according to the present embodiment, as a result of X-ray diffraction analysis (XRD), _{the ratio I1/I2 of the diffraction intensity I1 of CuO and the diffraction intensity I2 of Cu 2} O is 0.15 or less.

In addition, in the sputtering target of this embodiment, as a result of X-ray photoelectron spectroscopy (XPS), _{the ratio IP1/IP2 of the peak intensity IP1 of CuO and the peak intensity IP2 of Cu and Cu 2} O is 0.03 or more and 0.4 or less. Is within range.

In addition, in the sputtering target according to the present embodiment, the target as a whole has the property of a p-type semiconductor.

In addition, the resistance value of the sputtering target according to the present embodiment is 10 Ω·cm or less.

In addition, in the sputtering target according to the present embodiment, the density is in the range of 5.5 g/cm 3 or more and 7.5 g/cm 3 or less.

Below, the volume ratio of the copper oxide phase in the sputtering target of the present embodiment, the average particle diameter of the metallic copper phase, the variation in the resistance value, the diffraction intensity of X-ray diffraction analysis (XRD), and the peak of X-ray photoelectron spectroscopy (XPS) The reason for defining the strength and density as described above will be described.

(Volume ratio of copper oxide phase: more than 80 vol% and not more than 90 vol%)

In the sputtering target according to the present embodiment, since the copper oxide film is formed by DC sputtering, the abundance ratio of the metallic copper phase and the copper oxide phase becomes particularly important.

Here, when the volume ratio of the copper oxide phase is less than 80 vol%, there is a concern that a copper oxide film having characteristics as copper oxide cannot be formed because a relatively large amount of metallic copper exists in the formed copper oxide film.

On the other hand, when the volume ratio of the copper oxide phase exceeds 90 vol%, the resistance value of the entire target increases, and there is a fear that DC sputtering cannot be performed. In this embodiment, since the metallic copper phase is dispersed in an island phase, and the copper oxide phase present therebetween acts as a p-type semiconductor degenerated by reacting with the metallic copper phase, if the metallic copper phase is not sufficiently dispersed, the entire target It is thought that the resistance value of is increased.

For this reason, in the present embodiment, the volume ratio of the copper oxide phase is set within a range of more than 80 vol% and not more than 90 vol%.

Further, in order to reliably form a copper oxide film having excellent properties, it is preferable to set the volume ratio of the copper oxide phase to 85 vol% or more. On the other hand, in order to further lower the resistance value of the sputtering target, the volume ratio of the copper oxide phase is preferably set to 85 vol% or less. That is, it is preferable to appropriately adjust the volume ratio of the copper oxide phase in consideration of the required characteristics or resistance values in the range of more than 80 vol% and not more than 90 vol% of the copper oxide phase.

(Average particle diameter of metallic copper phase: 10 μm or more and 200 μm or less)

In order to form a copper oxide film by DC sputtering, it is necessary to ensure conductivity in the entire target.

In this embodiment, since the average particle diameter of a metallic copper phase is 200 micrometers or less and it is comparatively fine, the metallic copper phase becomes relatively uniformly dispersed. Here, in the present embodiment, as described above, the metallic copper phase is dispersed in an island phase, and the copper oxide phase present therebetween acts as a p-type semiconductor, so that the metallic copper phase is relatively uniformly dispersed, Conductivity can be ensured in the entire target, and DC sputtering can be performed stably.

Further, in the case of manufacturing the sputtering target according to the present embodiment, metallic copper powder is used. However, by specifying the average particle diameter of the metallic copper phase to be 10 μm or more, it is not necessary to make the particle diameter of the metallic copper powder excessively fine, and the metal Oxidation of copper powder can be suppressed.

From the above point, in this embodiment, the average particle diameter of the metallic copper phase is set within the range of 10 micrometers or more and 200 micrometers or less. In addition, in order to ensure conductivity in the entire target and perform DC sputtering more stably, the upper limit of the average particle diameter of the metallic copper phase is preferably 150 µm or less, and more preferably 100 µm or less. Further, in order to reliably suppress oxidation of the metallic copper powder as a raw material, the lower limit of the average particle diameter of the metallic copper phase is preferably 20 µm or more, and more preferably 30 µm or more.

(Variation from the average value of the resistance value on the target sputtering surface: 50% or less)

In the sputtering target according to the present embodiment, conductivity is ensured by dispersing the metallic copper phase, and DC sputtering becomes possible. Here, when the deviation from the average value of the resistance value on the target sputtering surface exceeds 50%, the metallic copper phase is not uniformly dispersed, and there is a fear that DC sputtering cannot be performed stably. In addition, there is a fear that abnormal discharge may occur during sputtering.

For this reason, in this embodiment, the deviation from the average value of the resistance value on the target sputtering surface is set to 50% or less. In addition, in order to uniformly disperse the metallic copper phase to reliably perform DC sputtering, the deviation from the average value of the resistance value on the target sputtering surface is preferably 40% or less, and 30% or less. More preferable.

Here, in the present embodiment, when the shape of the sputtering target is a flat plate, and the target sputtering surface is circular, as shown in Fig. 1, while passing through the center 1 of the circle and the center of the circle, The resistance value is measured at five points of the outer circumferential portions (2), (3), (4), and (5) on two orthogonal straight lines, and the average value of the resistance values on the target sputtering surface is determined by the following equation. You are looking for the deviation.

In addition, when the shape of the sputtering target is a flat plate and the target sputtering surface forms a square, as shown in Fig. 2, the intersection 1 where the diagonals intersect, the corners 2 and 3 on each diagonal, The resistance value is measured at the five points of (4) and (5), and the deviation with respect to the average value of the resistance value on the target sputtering surface is calculated|required by the following formula.

In addition, when the shape of the sputtering target is a cylinder and the target sputtering surface is a cylindrical outer circumferential surface, as shown in Fig. 3, (1) and (2) at intervals of 90° in the outer circumferential direction from the half point in the axial line (O) direction. ), (3) and (4), the resistance value is measured at four points, and the deviation from the average value of the resistance value on the target sputtering surface is determined by the following equation.

(Variation)% = Standard deviation/average value × 100

(Resistance value: 10 Ω·cm or less)

In order to perform DC sputtering, in the sputtering target according to the present embodiment, the resistance value is preferably 10 Ω·cm or less, and more preferably 1 Ω·cm or less.

In addition, the resistance value of the sputtering target in this embodiment is taken as the average value of the five measured values mentioned above.

(Ratio of the diffraction intensity I1 of CuO and the diffraction intensity I2 of Cu ₂ O: 0.15 or less)

When the sputtering target is produced by sintering, CuO and metallic copper react to produce Cu ₂ O. Here, if the CuO of the diffraction intensity ratio I1 and I1 / I2 of the diffraction intensity I2 of the Cu ₂ O less than or equal to 0.15, the ratio of CuO is lower, the metallic copper and the CuO is possible to sufficiently react. For this reason, variation in the resistance value in the target is suppressed, and occurrence of abnormal discharge is suppressed.

From the above point, in this embodiment, the ratio I1/I2 of the diffraction intensity I1 of CuO and the diffraction intensity I2 of Cu ₂ O is set to 0.15 or less. In addition, in order to reliably suppress the variation of the resistance value and suppress the occurrence of abnormal discharge, _{the ratio I1/I2 of the diffraction intensity I1 of CuO and the diffraction intensity I2 of Cu 2} O is preferably 0.1 or less, and is 0.05 or less. It is more preferable to do it.

(Ratio IP1/IP2 of the peak intensity IP1 of CuO and _{the peak intensity IP2 of Cu and Cu 2} O in X-ray photoelectron spectroscopy (XPS): 0.03 or more and 0.4 or less)

When the sputtering target is produced by sintering as described above, CuO and metallic copper react to produce Cu ₂ O. Here, when the ratio IP1/IP2 of the peak intensity IP1 of CuO and _{the peak intensity IP2 of Cu and Cu 2} O in X-ray photoelectron spectroscopy (XPS) is 0.03 or more, CuO is present on the copper oxide, and the sintered compact The strength of is improved, and the occurrence of cracks at the time of manufacture can be suppressed. On the other hand, when IP1/IP2 is 0.4 or less, metallic copper and CuO become fully reacted, variation in resistance value in the target is suppressed, and occurrence of abnormal discharge is suppressed.

_{From the above point, in this embodiment, the ratio IP1/IP2 of the peak intensity IP1 of CuO and the peak intensity IP2 of Cu and Cu 2} O in the X-ray photoelectron spectroscopy (XPS) is in the range of 0.03 or more and 0.4 or less. I am setting it to mine. In addition, in order to improve the strength of the sintered body and reliably suppress cracks during manufacture, the lower limit of IP1/IP2 described above is preferably 0.05 or more, and more preferably 0.1 or more. In addition, in order to reliably suppress the variation of the resistance value and suppress the occurrence of abnormal discharge, the upper limit of IP1/IP2 described above is preferably set to 0.3 or less, and more preferably 0.2 or less.

In addition, since it is difficult to separate the peak _{of Cu and the peak of Cu 2} O in X-ray photoelectron spectroscopy (XPS) as shown in FIG. 5, the peak intensity IP _{2 of Cu and Cu 2 O was used.} It defines the proportion of CuO present.

(Density: 5.5 g/cm 3 or more and 7.5 g/cm 3 or less)

When the density of the sputtering target is 5.5 g/cm 3 or more, voids existing on the target sputtering surface can be reduced, and occurrence of abnormal discharge during sputtering can be suppressed. On the other hand, when the density of the sputtering target is 7.5 g/cm 3 or less, workability is improved and the sputtering target is easily formed.

For this reason, in this embodiment, the density of the sputtering target is defined within the range of 5.5 g/cm 3 or more and 7.5 g/cm 3 or less.

Further, in order to reliably suppress abnormal discharge during sputtering, the lower limit of the density of the sputtering target is preferably 6.0 g/cm 3 or more, and more preferably 6.2 g/cm 3 or more. Further, in order to reliably secure the workability of the sputtering target, the upper limit of the density of the sputtering target is preferably 7.0 g/cm 3 or less, and more preferably 6.8 g/cm 3 or less.

(Method of manufacturing sputtering target)

Next, a method of manufacturing a sputtering target according to the present embodiment will be described.

First, metal copper powder and copper oxide powder are prepared. Here, it is preferable to use a thing of purity 4N or more as a metallic copper powder. Moreover, by adjusting the particle diameter of this metallic copper powder, it becomes possible to control the average particle diameter of a metallic copper phase in a sputtering target. Specifically, it is preferable to make the average particle diameter of the metallic copper powder within the range of 10 micrometers or more and 200 micrometers or less.

Further, as the copper oxide powder, CuO powder, Cu ₂ O powder, and mixed powders thereof can be used. As for the CuO powder and the Cu ₂ O powder, it is preferable to use a thing of purity 2N or more. The average particle diameter of the CuO powder and the Cu ₂ O powder is preferably in the range of 1 µm or more and 30 µm or less.

Next, the weighed metallic copper powder and copper oxide powder are mixed by a mixing device such as a ball mill, Henschel mixer, and rocking mixer to obtain a raw material powder. At this time, in order to prevent oxidation of the metallic copper powder, the atmosphere in the mixing device is preferably an inert gas atmosphere such as Ar.

Next, using the above-described raw material powder, it is sintered by hot pressing or the like to obtain a sintered body. By machining the obtained sintered body, the sputtering target of this embodiment is produced. In addition, it is preferable that the sintering temperature is 600°C or more and 900°C or less, the holding time is in the range of 30 min or more and 600 min or less, and the pressurization pressure is in the range of 10 MPa or more and 50 MPa or less.

Here, in the case of using CuO powder as the copper oxide powder, the reaction between CuO and Cu can be accelerated by setting the sintering temperature to 720° C. or higher, and it becomes possible to reduce the presence ratio of CuO in the sputtering target.

In the sputtering target of the present embodiment having the above configuration, since the volume ratio of the copper oxide phase exceeds 80 vol%, the copper oxide phase is sufficiently present, and the copper oxide film is formed without sputtering in the presence of oxygen gas. Can be formed. Further, since the volume ratio of the copper oxide phase is within the range of 90 vol% or less, and the particle diameter of the metallic copper phase in the target structure is within the range of 10 µm or more and 200 µm or less, the metallic copper phase is relatively uniformly dispersed, and the entire target As a result, conductivity is ensured. Thereby, a copper oxide film can be formed by DC sputtering.

In addition, in the sputtering target according to the present embodiment, since the average particle diameter of the metallic copper phase is 200 µm or less, the metallic copper phase is finely dispersed in the target, and conductivity can be ensured throughout the target. Thereby, DC sputtering can be performed stably. On the other hand, since the average particle diameter of the metallic copper phase is 10 μm or more, there is no need to excessively reduce the particle diameter of the metallic copper powder during target manufacturing, and oxidation of metallic copper powder can be suppressed, and sintering can be performed satisfactorily. can do.

In addition, in this embodiment, since the deviation from the average value of the specific resistance value on the target sputtering surface is 50% or less, conductivity is sufficiently secured as a whole, and a copper oxide film is stably formed by DC sputtering. It becomes possible to do.

Further, in this embodiment, the metallic copper phase is dispersed in an island phase, and the copper oxide phase present between these metallic copper phases reacts with the metallic copper phase and acts as a degenerate p-type semiconductor, so that the properties of the p-type semiconductor as a whole target It has, and it is thought that electroconductivity is secured. Therefore, a copper oxide film can be formed by DC sputtering.

In addition, in this embodiment, since the resistance value of the sputtering target is 10 Ω·cm or less, DC sputtering can be reliably performed.

In addition, in this embodiment, as a result of X-ray diffraction analysis (XRD), _{the ratio I1/I2 of the diffraction intensity I1 of CuO and the diffraction intensity I2 of Cu 2} O is 0.15 or less, so that Cu is uniformly formed as a copper oxide phase. ₂ O is dispersed, and variations in resistance values in the target can be suppressed.

In addition, in this embodiment, as a result of X-ray photoelectron spectroscopy analysis, since _{the ratio IP1/IP2 of the peak intensity IP1 of CuO and the peak intensity IP2 of Cu and Cu 2} O is 0.03 or more, the strength of the sintered body is improved, The occurrence of cracks in manufacturing can be suppressed. Moreover, since IP1/IP2 is set to 0.4 or less, the presence ratio of CuO in the copper oxide phase decreases, and variations in resistance values in the target can be suppressed.

Further, in the sputtering target according to the present embodiment, since the density is 5.5 g/cm 3 or more, occurrence of abnormal discharge during sputtering can be suppressed. On the other hand, since the density is 7.5 g/cm 3 or less, workability is ensured, and this sputtering target can be formed satisfactorily.

As described above, embodiments of the present invention have been described, but the present invention is not limited thereto, and can be appropriately changed within a range not departing from the technical idea of the present invention.

Example

Hereinafter, the results of a confirmation experiment conducted to confirm the effectiveness of the present invention will be described.

(Sputtering target)

As raw material powder, metallic copper powder (purity: 99.9 mass% or more, average particle diameter is described in Table 1), CuO powder (purity: 99 mass% or more, average particle diameter 5 µm), Cu ₂ O powder (purity: 99 mass% As described above, an average particle diameter of 3 µm) was prepared.

These raw materials were weighed so as to have the mol ratio shown in Table 1, and the weighed raw materials and zirconia balls (diameter: 5 mm) three times the weight of the raw materials were put into a container of a ball mill device in an Ar gas atmosphere, Mix for 3 hours.

After sieving the obtained raw material powder, it was filled into a hot-pressed flat plate and a cylindrical molding mold, and under pressure of 200 kgf/cm 2, at the sintering temperature shown in Table 1, the plate shape was 3 hours and the cylindrical shape was 5 Kept time.

The obtained sintered body was machined to prepare a sputtering target for evaluation (126 mm × 178 mm × 6 mm, cylindrical shape: (φ155 mm -φ135 mm) × 150 mmL). And it evaluated about the following items. The evaluation results are shown in Tables 1 and 2.

(Volume ratio of copper oxide phase in target)

The concentration (atomic %) of copper in the target is measured by a titration method, and the remainder is calculated as oxygen.

It was assumed that the calculated oxygen was present as the total amount of Cu ₂ O, and the volume ratio with copper was calculated. In addition, since the public is not considered, the volume ratio here excludes the public.

(Composition of target)

The concentration of copper in the target was measured by a titration method, and the remainder was calculated as oxygen.

(Composition of the membrane)

The concentration of copper in the film was measured by a titration method, and the remainder was calculated as oxygen.

(Target density)

The density was calculated from the weight and dimensions.

(Target resistance value)

About the sputtering target, the resistivity was measured by the resistance measuring apparatus. In the case of a flat plate shape, with respect to the measurement points of five points (1 to 5) in the target sputtering surface as shown in Figs. 1 and 2, in the case of a cylindrical shape, four points (1 to 5) in the target sputtering surface as shown in Fig. 3 About the measurement point of 4), the resistivity was measured. Table 2 shows the average value of the measured in-plane resistivity. In this measurement, as a resistance measuring device, a low resistivity meter (Loresta-GP) manufactured by Mitsubishi Chemical Co., Ltd. was used, and the resistivity (Ω·cm) was measured by a four-probe method.

The temperature at the time of measurement was measured at 23±5°C, and the humidity was measured at 50±20%.

(Variation)% = Standard deviation/average value × 100

(pn judgment)

With respect to the sputtering target, PN determination was performed by a PN determination machine. In the case of a flat plate shape, with respect to the measurement point of one point (1) in the target sputtering surface as shown in FIGS. For, PN was determined. Table 2 shows the results of determination. In this measurement, as a PN determination device, a PN determination device (MODEL PN-01) manufactured by NPS Corporation was used, and PN determination was performed with a thermoelectric probe. The temperature at the time of measurement was measured at 23±5°C, and the humidity was measured at 50±20%.

(Particle diameter of metallic copper phase)

The size was confirmed from the IQ map obtained by EBSD for the particles of the metallic copper phase in the structure of the sputtering target. In addition, in the IQ map, the particle size was quantitatively measured by observing a cross-sectional range of 500 µm × 750 µm.

In addition, EBSD collected the pattern using the OIM Data Collection of TSL Solutions, Inc., and calculated the size of the particles using the company's OIM Analysis 5.31.

(X-ray diffraction analysis)

X-ray diffraction analysis (XRD) was performed under the following conditions. In addition, the calculation of the intensity ratio was calculated by the intensity of the 200 plane of the intensity of the 111 plane of I1 CuO, Cu ₂ O as I2. An example of the analysis result is shown in FIG. 4.

Preparation of sample: The sample was polished with SiC-Paper (grit 180), and then used as a measurement sample.

Equipment: manufactured by Rigaku Electric Corporation (RINT-Ultima/PC)

Province (管球): Cu

Tube voltage: 40 kV

Tube current: 40 ㎃

Scanning range (2θ): 5° ∼ 80°

Slit size: Divergence (DS) 2/3 degrees, Scattering (SS) 2/3 degrees, Light reception (RS) 0.8 ㎜

Measurement step width: 0.02 degrees at 2θ

Scan speed: 2 degrees per minute

Sample stand rotation speed: 30 rpm

(X-ray photoelectron spectroscopy analysis)

X-ray photoelectron spectroscopy (XPS) was performed under the following conditions. Further, the measurement surface of the measurement sample was surface-polished with a polishing paper #2000, and Ar sputtering was performed from the outermost surface for analysis. In addition, this measurement was performed 20 minutes after the start of sputtering, and the data of the Cu2p3/2 spectrum was used. An example of the analysis result is shown in FIG.

Device: ULVAC-PHI PHI5000 VersaProbeII

X-ray source: Monochromated AlKα 50 W

Pass Energy: 187.85 eV (Survey), 46.95, 58.7 eV (Profile)

Measurement interval: 0.8 eV/step (Survey), 0.1, 0.125 eV/step (Profile)

Photoelectron extraction angle to the sample surface: 45 deg

Analysis area: about 200 μmφ

(Cracking at the time of manufacture)

Twenty sputtering targets were produced under the above-described conditions, and the number of cracks was counted at that time.

(Number of abnormal discharges)

With respect to the obtained sputtering target, the number of occurrences of abnormal discharge during sputtering was measured in the following procedure.

In the flat sputtering target, the film formation test was performed under the following film formation conditions.

Power: DC 600 W

Total pressure: 0.4 Pa

Sputtering gas: Ar =50 sccm

Target-substrate (TS) distance: 70 ㎜

In addition, in the cylindrical sputtering target, a film forming test was performed under the following film forming conditions.

Target size: (φ155 ㎜-φ135 ㎜) × 150 mmL (4 divisions)

Power: DC 2000 W

Total pressure: 0.4 Pa

Sputtering gas: Ar = 160 sccm

Target-substrate (TS) distance: 60 ㎜

In the above film forming conditions, sputtering was performed for 1 hour, and the number of occurrences of abnormal discharge was automatically measured with an arcing counter attached to the sputtering power supply device.

(Membrane resistance value)

In this measurement, a low resistivity meter (Loresta-GP) manufactured by Mitsubishi Chemical Co., Ltd. was used as a resistance measuring device, and sheet resistance (Ω/sq) was measured by a four-probe method. The temperature at the time of measurement was measured at 23±5°C, and the humidity was measured at 50±20%.

The sample used for the measurement was prepared under the above-described sputtering conditions. The film was formed on a glass substrate with a target film thickness of 200 nm.

In Comparative Examples 1 and 3 in which the volume ratio of the copper oxide phase exceeded 90 vol%, the resistance value was high, and DC sputtering was not possible.

In Comparative Examples 2 and 4 in which the volume ratio of the copper oxide phase was 80 vol% or less, the resistance value of the formed copper oxide film was low, and the characteristics as a copper oxide film were insufficient.

In Comparative Example 5 in which the deviation from the average value of the resistance value on the target sputtering surface exceeded 50%, the number of occurrences of abnormal discharge was large, and sputtering could not be performed stably.

In Comparative Example 6 in which the particle diameter of the metallic copper phase was less than 10 µm, the number of occurrences of abnormal discharge was large, and sputtering was not possible stably.

In Comparative Example 7 in which the particle diameter of the metallic copper phase exceeded 200 µm, the number of occurrences of abnormal discharge was large, and sputtering was not possible stably.

On the contrary, according to the example of the present invention, it was confirmed that the resistance value was low, DC sputtering was possible, and a copper oxide film having excellent properties could be formed.

In addition, as a result of X-ray photoelectron spectroscopy analysis, _{the ratio IP1/IP2 of the peak intensity IP1 of CuO and the peak intensity IP2 of Cu and Cu 2} O was in the range of 0.03 or more and 0.4 or less. , 10 to 14, 16, and 17, it was confirmed that the occurrence of cracks during production was suppressed.

Industrial applicability

A copper oxide film as an inorganic nanocoating layer for suppressing adhesion between adjacent films can be formed with good precision and high efficiency, and can be applied to a conductive film such as a touch sensor.

O: axis line

Claims (6)

It has a metallic copper phase and a copper oxide phase, and the volume ratio of the said copper oxide phase exceeds 80 vol% and is in a range of 90 vol% or less,
The deviation from the average value of the resistance value on the target sputtering surface is 50% or less,
A sputtering target, characterized in that the average particle diameter of the metallic copper phase in the target structure is in the range of 10 µm to 200 µm, and has properties of a p-type semiconductor. delete The method of claim 1,
A sputtering target, characterized in that the resistance value is 10 Ω·cm or less. The method according to claim 1 or 3,
A sputtering target, wherein the ratio I1/I2 of the diffraction intensity I1 of CuO and the diffraction intensity I2 of Cu _{2 O is 0.15 or less.} The method according to claim 1 or 3,
As a result of X-ray photoelectron spectroscopy analysis, _{the ratio IP1/IP2 of the peak intensity IP1 of CuO and the peak intensity IP2 of Cu and Cu 2} O is in a range of 0.03 or more and 0.4 or less. The method according to claim 1 or 3,
A sputtering target, characterized in that the density is in a range of 5.5 g/cm 3 or more and 7.5 g/cm 3 or less.

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