JP2018031064A - Copper stock for sputtering target - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copper stock for sputtering target that can prevent the occurrence of abnormal discharge for stable deposition, and can be produced at low cost.SOLUTION: A copper stock for sputtering target contains at least one additional element selected from Zr, Ti, Mg, Mn, La, Ca in a range of 0.001 mass% or more and 0.008 mass% or less, with the total of the content of Cu and the content of the additional element being 99.99 mass% or more. The content of S is preferably 0.005 mass% or less.SELECTED DRAWING: None

Description

  The present invention relates to a copper material for a sputtering target used when forming a wiring film (copper film) in a semiconductor device, a flat panel display such as a liquid crystal or organic EL panel, a touch panel, and the like.

Conventionally, Al is widely used as a wiring film for semiconductor devices, flat panel displays such as liquid crystal and organic EL panels, and touch panels. Recently, miniaturization (narrowing) and thinning of the wiring film have been attempted, and a wiring film having a lower specific resistance than before has been demanded.
Accordingly, with the miniaturization and thinning of the wiring film described above, a wiring film made of copper (Cu), which is a material having a specific resistance lower than that of Al, is provided.

  By the way, the above-described wiring film is usually formed in a vacuum atmosphere using a sputtering target. As a sputtering target for forming a copper wiring film, for example, those disclosed in Patent Documents 1 and 2 have been proposed.

Here, in Patent Document 1, pure copper having a purity of 99.995 wt% or more has a substantially recrystallized structure, an average crystal grain size of 80 microns or less, and a Vickers hardness of 100 Hv or less. A copper target for sputtering has been proposed.
In this patent document 1, the generation of coarse clusters is suppressed by refining crystal grains as a recrystallized structure and reducing the amount of strain, and the direction of the copper particles is aligned and the copper wiring is uniformly formed. The purpose is to film.

Patent Document 2 discloses a step of creating a melting ingot from electrolytic copper by a zone melt method, a step of creating a high purity copper ingot by vacuum melting the melting ingot, and the high purity copper ingot from 100 to 100%. By comprising a step of recrystallization by heat treatment at 600 ° C. and a step of machining the heat-treated high-purity copper ingot, the oxygen content is 10 ppm or less and the sulfur content is 1 ppm or less. There has been proposed a sputtering target manufacturing method for obtaining a sputtering target composed of a high-purity copper base material having an iron content of 1 ppm or less and a purity of 99.999% or more.
This patent document 2 is intended to produce a sputtering target capable of forming a dense wiring film with good fluidity and good dense adhesion at the time of film formation.

Japanese Patent Laid-Open No. 11-158614 JP 2007-023390 A

By the way, when film formation is performed using a sputtering target, abnormal discharge (arcing) may occur due to concentration of electric charges, and thus a uniform wiring film may not be formed. Here, abnormal discharge is a phenomenon in which an extremely high current suddenly and suddenly flows compared to that during normal sputtering, and an abnormally large discharge occurs suddenly. This may cause generation of particles and / or non-uniform thickness of the wiring film. Therefore, it is desirable to avoid as much as possible abnormal discharge during film formation.
In particular, in recent years, in semiconductor devices, flat panel displays such as liquid crystal and organic EL panels, touch panels, etc., higher density of wiring films has been demanded, and wiring that has been made finer and thinner than before. It is necessary to form the film stably.

  Here, in the copper target for sputtering described in Patent Document 1, it is described that the average crystal grain size is refined and the amount of strain is reduced as a recrystallized structure, but no particular mention is made of impurities. . For example, when sulfur (S) is contained as an impurity, there is a possibility that a uniform recrystallized structure cannot be obtained because the progress of recrystallization is suppressed. For this reason, even if the average crystal grain size is small and the amount of strain is low as a whole, if there is an unrecrystallized region and there is a region where the amount of strain is locally high, abnormal discharge is likely to occur. there were.

  In addition, in the method for producing a sputtering target described in Patent Document 2, a melted ingot having a purity of 99.9995% is produced by the zone melt method and the amount of impurities is suppressed, but no consideration is given to the recrystallization behavior. In this case, the amount of distortion is not taken into consideration, and therefore, abnormal discharge may easily occur. Further, since the zone melt method is used, there is a problem that the production efficiency is greatly reduced.

  The present invention has been made in view of the circumstances described above, and provides a copper material for a sputtering target that can stably form a film while suppressing the occurrence of abnormal discharge and can be manufactured at low cost. The purpose is to do.

  In order to solve the above-mentioned problems, the copper material for a sputtering target of the present invention contains 0.001 mass% or more of one or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca. 0.008 mass% or less, and the total of the content of Cu and the content of the additive element is 99.99 mass% or more.

In the copper material for a sputtering target having this configuration, one or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca are added in a range of 0.001 mass% to 0.008 mass%. Since the total of the content of Cu and the content of the additive element is 99.99 mass% or more and is not purified more than necessary, it can be manufactured at a relatively low cost.
Further, since one or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca are contained in the range of 0.001 mass% to 0.008 mass%, S is added to these. It can fix as a compound with an additional element, and can suppress that the progress of recrystallization is inhibited by S. Therefore, a uniform recrystallized structure can be obtained and the occurrence of abnormal discharge (arcing) during film formation can be suppressed.

Here, in the copper raw material for sputtering targets of this invention, it is preferable that content of S shall be 0.005 mass% or less.
In this case, since the S content is limited to 0.005 mass% or less, S can be reliably fixed by the above-described additive element, a uniform recrystallized structure can be obtained, It is possible to suppress the occurrence of abnormal discharge (arcing). In addition, a decrease in conductivity can be suppressed.

Moreover, in the copper raw material for sputtering targets of this invention, it is preferable that the area ratio which the compound containing the said additional element and S occupies in the same plane as a sputtering surface is 0.4% or less.
In this case, since the area ratio occupied by the compound containing the additive element and S is suppressed to 0.4% or less, it is possible to suppress the increase in the recrystallization temperature and further promote the progress of the recrystallization, Generation of non-recrystallized regions can be further suppressed. Moreover, generation | occurrence | production of the abnormal discharge resulting from the compound containing an additive element and S can be suppressed reliably.

Furthermore, in the copper material for a sputtering target of the present invention, it is preferable that the Vickers hardness is 80 Hv or less.
In this case, it has a uniform recrystallized structure, and the strain is sufficiently released, so that the occurrence of abnormal discharge (arcing) during film formation can be reliably suppressed.

Moreover, in the copper raw material for sputtering targets of this invention, it is preferable that the standard deviation of the Vickers hardness measured in several places in the same plane as a sputtering surface is 10 or less.
In this case, since the strain is released uniformly, there is no region where the amount of strain is locally high, and the occurrence of abnormal discharge can be reliably suppressed.

The sputtering target of the present invention preferably has an average crystal grain size of 100 μm or less.
In this case, since the average crystal grain size is 100 μm or less and relatively fine, unevenness generated on the sputtering surface when the sputtering progresses is reduced, and the occurrence of abnormal discharge can be suppressed.

  According to the present invention, it is possible to provide a copper material for a sputtering target that can be stably formed while suppressing the occurrence of abnormal discharge and can be manufactured at low cost.

It is explanatory drawing which shows the measurement position of the Vickers hardness in the copper raw material for sputtering targets whose sputtering surface makes a circle. It is explanatory drawing which shows the measurement position of the Vickers hardness in the copper raw material for sputtering targets whose sputtering surface makes a rectangular shape. It is explanatory drawing which shows the measurement position of the Vickers hardness in the copper raw material for sputtering targets whose sputtering surface makes a cylindrical shape. It is a flowchart which shows an example of the manufacturing method of the copper raw material for sputtering targets which concerns on embodiment of this invention.

Below, the copper raw material for sputtering targets which concerns on one Embodiment of this invention is demonstrated.
The copper material for sputtering target according to this embodiment is a sputtering target used when a copper film used as a wiring film in a semiconductor device, a flat panel display such as a liquid crystal or organic EL panel, a touch panel, etc. is formed on a substrate. It will be the material of. In addition, as a copper raw material for sputtering targets, there exist a disk shape, a rectangular flat plate shape, and a cylindrical shape.

  And the composition of the copper raw material for sputtering targets which is this embodiment is 0.001 mass% or more and 0.008 mass% of 1 type, or 2 or more types of additional elements selected from Zr, Ti, Mg, Mn, La, and Ca. It contains within the following ranges, and the sum total of content of Cu and content of the said additional element shall be 99.99 mass% or more. In the present embodiment, the S content is 0.005 mass% or less.

Further, the copper material for sputtering target according to the present embodiment includes the above-described additive elements (one or more selected from Zr, Ti, Mg, Mn, La, and Ca) and S in the same plane as the sputtering surface. The area ratio occupied by the compound containing is 0.4% or less.
Furthermore, the copper material for sputtering targets according to this embodiment has a Vickers hardness of 80 Hv or less.
In addition, the copper material for a sputtering target according to the present embodiment has a standard deviation of Vickers hardness of 10 or less measured at a plurality of locations in the same plane as the sputtering surface.
Furthermore, the copper material for sputtering targets according to this embodiment has an average crystal grain size of 100 μm or less.

  The reason why the composition of the copper material for sputtering target according to the present embodiment, the area ratio of the compound on the sputtering surface, the Vickers hardness, the standard deviation of the Vickers hardness, and the average crystal grain size are defined as described above will be described below. .

(One or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca: 0.001 mass% to 0.008 mass%)
Since the above-mentioned additive element is an element having a lower free energy for sulfide generation than Cu, it is possible to form a compound with S (sulfur) and fix S. Thereby, recrystallization can be promoted.

  Here, when the content of one or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca is less than 0.001 mass%, S in copper is sufficiently fixed. There is a risk that it will not be possible. On the other hand, when the content of one or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca exceeds 0.008 mass%, many compounds containing the additive element and S are produced. Alternatively, the compound may become coarse and abnormal discharge due to this compound may occur.

For this reason, in the present embodiment, the content of one or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca is within a range of 0.001 mass% to 0.008 mass%. To do.
In order to more sufficiently fix S in copper, the lower limit of the content of one or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca is set to 0.0015 mass%. It is preferable to set it as above, and it is preferable to set it as 0.0020 mass% or more.
In order to suppress the occurrence of abnormal discharge due to the compound, the upper limit of the content of one or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca is set to 0.0060 mass. % Or less, and preferably 0.0040 mass% or less.

(Total of Cu content and additive element content is 99.99 mass% or more)
When forming a wiring film (high-purity copper film) by sputtering, it is preferable to reduce impurities as much as possible in order to suppress abnormal discharge (arcing). However, in order to increase the purity of the Cu content and the additive element content to 99.999 mass% or more, the manufacturing process becomes complicated and the manufacturing cost increases significantly. Therefore, in this embodiment, the manufacturing cost is reduced by setting the total of the Cu content and the additive element content to 99.99 mass% or more. Further, the upper limit of the total content of Cu and the content of additive elements is preferably less than 99.999 mass% from the viewpoint of reducing manufacturing costs.

(S: 0.005 mass% or less)
S is an element that inhibits the progress of copper recrystallization and lowers the electrical conductivity. Here, when the content of S exceeds 0.005 mass%, even when the above-described additive element is added, S cannot be sufficiently fixed, and recrystallization becomes insufficient. There is a possibility that an unrecrystallized region is generated and the amount of strain is locally non-uniform. Moreover, there exists a possibility that electrical conductivity may fall.
For this reason, it is preferable to limit the S content to 0.005 mass% or less in order to sufficiently advance the recrystallization so as to sufficiently uniform the strain amount and to ensure the electrical conductivity. The S content is preferably 0.003 mass% or less, and more preferably 0.001 mass% or less.

(Area ratio occupied by compound containing additive element and S in the same plane as the sputtering surface: 0.4% or less)
By adding one or more additional elements selected from Zr, Ti, Mg, Mn, La, and Ca, a compound containing the additional element and S is generated. May be mixed in the sputtering target copper material. When the number of compounds containing this additive element and S increases or when the compound becomes coarse, the recrystallization temperature may be increased and recrystallization may be suppressed. In addition, abnormal discharge may occur due to this compound during film formation.
For this reason, in this embodiment, the area ratio which the compound containing an additive element and S occupies is 0.4% or less. Note that the area ratio occupied by the compound containing the additive element and S is preferably 0.3% or less, and more preferably 0.1% or less.

(Vickers hardness: 80Hv or less)
When recrystallization is promoted and the strain is sufficiently released, the Vickers hardness becomes low.
Here, if Vickers hardness is 80 Hv or less, recrystallization will fully advance and distortion will be released.
For this reason, in this embodiment, the Vickers hardness is limited to 80 Hv or less. The Vickers hardness is preferably 65 Hv or less, and more preferably 50 Hv or less.
In the present embodiment, the average value of Vickers hardness measured at a plurality of locations in the same plane as the sputtering surface is 80 Hv or less.

(Standard deviation of Vickers hardness measured at multiple points in the same plane as the sputtering surface: 10 or less)
In the case where there is an unrecrystallized region and a region having high strain locally exists, the Vickers hardness varies.
Here, if the standard deviation of the Vickers hardness measured at a plurality of locations in the same plane as the sputtering surface is 10 or less, the variation in the Vickers hardness is small, and there is almost no region where the strain is locally high.
For this reason, in this embodiment, the standard deviation of the Vickers hardness measured at a plurality of locations in the same plane as the sputtering surface is limited to 10 or less. The standard deviation of Vickers hardness measured at a plurality of locations in the same plane as the sputtering surface is preferably 5 or less, and more preferably 3 or less.

  Here, in this embodiment, the measurement position of the above-mentioned Vickers hardness is set according to the shape of the copper material for sputtering targets.

  When the sputtering surface of the copper material for the sputtering target is circular, as shown in FIG. 1, the center (1) of the circle and the outer peripheral portion on two straight lines that pass through the center of the circle and are orthogonal to each other Vickers hardness is measured at five locations (2), (3), (4), and (5), and the average value and standard deviation are calculated.

  When the sputtering surface of the copper material for the sputtering target is rectangular, as shown in FIG. 2, the intersection (1) where the diagonal lines intersect and the corners (2), (3), (4) on each diagonal line , (5) Vickers hardness was measured at five locations, and the average value and standard deviation were calculated.

  When the sputtering surface of the copper material for sputtering target forms a cylindrical surface, as shown in FIG. 3, a total of nine locations (A1 to A3, Bickers hardness is measured by B1-B3, C1-C3), and the average value and standard deviation are calculated.

(Average crystal grain size: 100 μm or less)
Since the sputtering rate varies depending on the crystal orientation, when the sputtering proceeds, irregularities corresponding to the crystal grains are generated on the sputtering surface due to the above-described difference in the sputtering rate.
Here, when the average crystal grain size exceeds 100 μm, the anisotropy of crystal orientation becomes remarkable, and the unevenness generated on the sputtering surface becomes large, and electric charges are concentrated on the convex part, and abnormal discharge is likely to occur.
For these reasons, the average crystal grain size is regulated to 100 μm or less in the sputtering target copper material of this embodiment. In the present embodiment, the average crystal grain size is preferably 80 μm or less, and more preferably 50 μm or less.

  Next, an example of the manufacturing method of the copper material for sputtering targets which is this embodiment is demonstrated with reference to FIG.

(Melting / Casting Process S01)
First, a copper raw material having a copper purity of 99.99 mass% or more is melted to obtain a molten copper. Next, one or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca are added to the obtained molten copper so as to have a predetermined concentration, and component preparation is performed. Obtain a copper alloy melt.
And in this embodiment, the ingot of predetermined cross-sectional shape (For example, rectangular shape, circular shape, annular shape) is manufactured using a continuous casting apparatus.

(Cold processing step S02)
Next, cold working is performed on the ingot having a predetermined cross-sectional shape. The processing rate in this cold working is preferably in the range of 40.0% or more and 99.9% or less.

(Heat treatment step S03)
Next, heat treatment is performed after cold working. In this case, the heat treatment temperature is preferably in the range of 100 ° C. to 600 ° C., the holding time is preferably in the range of 30 min to 300 min, and the heat treatment temperature is in the range of 150 ° C. to 400 ° C., the holding time. Is preferably in the range of 60 min to 180 min. By this heat treatment step S03, recrystallization proceeds and the strain applied in the cold working step S02 is released.

(Machining process S04)
Next, machining is performed after the heat treatment to remove the oxide film on the surface and finish it into a predetermined shape.
Through the steps as described above, the copper material for sputtering target according to the present embodiment is manufactured.

According to the copper material for a sputtering target of the present embodiment configured as described above, one or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca are added by 0.001 mass. % In the range of 0.008 mass% or less, the sum of the content of Cu and the content of the additive element is 99.99 mass% or more, because it is not highly purified than necessary, It can be manufactured at a relatively low cost.
Further, since one or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca are contained in the range of 0.001 mass% to 0.008 mass%, S is added to these. It can fix as a compound with an additional element, and can suppress that the progress of recrystallization is inhibited by S. Therefore, a uniform recrystallized structure can be obtained and the occurrence of abnormal discharge (arcing) during film formation can be suppressed.

  In the present embodiment, since the S content is limited to 0.005 mass% or less, the S content can be increased by one or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca. Can be reliably fixed, a uniform recrystallized structure can be obtained, and the occurrence of abnormal discharge (arcing) during film formation can be suppressed. In addition, a decrease in conductivity can be suppressed.

  Furthermore, in this embodiment, since the area ratio occupied by the compound containing the additive element and S in the same plane as the sputtering surface is suppressed to 0.4% or less, the recrystallization temperature is prevented from being increased and the recrystallization temperature is further increased. Crystallization can be promoted, and generation of an unrecrystallized region can be further suppressed. Moreover, generation | occurrence | production of the abnormal discharge resulting from the compound containing an additive element and S can be suppressed reliably.

Furthermore, in this embodiment, since the Vickers hardness is 80 Hv or less, it has a uniform recrystallized structure, and further, the strain is sufficiently released, and abnormal discharge (arcing) during film formation occurs. Occurrence can be reliably suppressed.
In this embodiment, since the standard deviation of the Vickers hardness measured at a plurality of locations in the same plane as the sputtering surface is 10 or less, the strain is released uniformly and the amount of strain is locally high. There is no region, and the occurrence of abnormal discharge can be reliably suppressed.

  Furthermore, in this embodiment, as shown in FIGS. 1 to 3, since the measurement locations of the Vickers hardness are defined according to the shape of the copper material for the sputtering target, a plurality of locations in the same plane as the sputtering surface The average value and standard deviation of the Vickers hardness measured in (1) can be appropriately calculated, and a copper material for a sputtering target having uniform strain can be obtained.

  Further, in this embodiment, since the average crystal grain size is made relatively small as 100 μm or less, the unevenness generated on the sputtering surface when the sputtering proceeds is reduced, and the occurrence of abnormal discharge can be suppressed.

  Further, in the present embodiment, the cold working step S02 and the heat treatment step S03 are performed after the melting / casting step S01, and as described above, selected from Zr, Ti, Mg, Mn, La, and Ca. Since S (sulfur) is fixed by one or more additive elements and the progress of recrystallization is promoted, a uniform recrystallized structure can be obtained.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this, It can change suitably in the range which does not deviate from the technical idea of the invention.
In the present embodiment, the sputtering target for forming a high-purity copper film as the wiring film has been described as an example. However, the present invention is not limited to this, and the present invention is applicable even when the copper film is used for other purposes. be able to.

  About the manufacturing method of the copper raw material for sputtering targets, it is not limited to this embodiment, The thing manufactured by the other manufacturing method may be used. For example, a hot working process may be provided after the melting / casting process. Moreover, you may obtain an ingot without using a continuous casting apparatus.

  Below, the result of the evaluation test evaluated about the copper raw material for sputtering targets which is this embodiment mentioned above is demonstrated.

Prepare a copper raw material having a purity of 99.99 mass% or more, melt a molten copper so as to have the composition shown in Table 1, and obtain an ingot having a rectangular cross section of 50 mm × 200 mm using a continuous casting apparatus. It was.
The obtained ingot was cold-rolled at the processing rates shown in Table 2. Thereafter, heat treatment was performed under the conditions shown in Table 2.
Thereafter, cutting was performed to obtain a copper material for a sputtering target having a rectangular shape of 10 mm × 130 mm × 140 mm.

  About the obtained copper material for sputtering targets, the area ratio occupied by the additive element and the compound containing S in the same plane as the sputtering surface, the average value and standard deviation of Vickers hardness, the average crystal grain size, the electrical conductivity, the number of abnormal discharge occurrences Was evaluated by the following procedure. The evaluation results are shown in Table 2.

(Area ratio of compound)
Surface analysis at a visual field of 60 μm × 80 μm was performed with SEM-EPMA, and the case where the additive elements M and S were detected at the same location was regarded as an MS compound. ) × 100 ”, the area ratio was calculated.

(Vickers hardness)
In the same plane as the sputtering surface of the copper material for the sputtering target, Vickers hardness was measured with a Vickers hardness tester in accordance with JIS Z 2244 at the position shown in FIG. 2, and the average value and standard deviation were calculated. . The evaluation results are shown in Table 2.

(Average crystal grain size)
A specimen for observation is taken from the position shown in FIG. 2 on the same plane as the sputtering surface of the copper material for the sputtering target, and the microstructure is observed using an optical microscope, based on JIS H 0501: 1986 (cutting method). The crystal grain size was measured, and the average crystal grain size was calculated. The evaluation results are shown in Table 2.

(Deposition conditions)
The obtained copper material for sputtering target was joined to a backing plate, and a copper thin film was formed under the following conditions.
Sputtering voltage: 3000W
Ultimate vacuum: 5 × 10 ⁻⁴ Pa
Sputtering gas: Ar, 0.4 Pa
Sputtering was performed for 1 hour under the above film formation conditions, and the number of occurrences of abnormal discharge was automatically measured by an arcing counter attached to the sputtering power supply. The evaluation results are shown in Table 2.

In Comparative Example 1 in which one or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca were not added, the standard deviation of Vickers hardness was large, and the number of abnormal discharge occurrences was relatively high. Increased. It is presumed that the progress of recrystallization was hindered by S, an unrecrystallized region was present, and a region with high strain was present locally.
In Comparative Example 2 in which one or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca are added in excess of 0.008 mass%, the area ratio of the compound is high, and abnormal discharge occurs. The number of times has become relatively large. Also, the conductivity was lowered.
In Comparative Example 3 in which the total of the Cu content and the additive element content was less than 99.99 mass%, the Vickers hardness was high and the standard deviation was large. In addition, the average crystal grain size was large, and the number of abnormal discharges increased. It is presumed that the recrystallization was insufficient and the strain was high.

On the other hand, it contains one or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca within a range of 0.001 mass% to 0.008 mass%, and contains Cu. According to Invention Example 1-23, in which the total of the amount and the content of the additive element was 99.99 mass% or more, the number of occurrences of abnormal discharge was small. It is presumed that recrystallization was promoted and the strain was released uniformly.
From the above, it was confirmed that according to the copper material for sputtering target of the present invention, it is possible to stably form a film while suppressing the occurrence of abnormal discharge.

Claims (6)

  One or more additive elements selected from Zr, Ti, Mg, Mn, La, and Ca are contained within a range of 0.001 mass% to 0.008 mass%, and the Cu content and the additive elements A copper material for a sputtering target, wherein the total content of the sputtering target is 99.99 mass% or more.   The copper material for a sputtering target according to claim 1, wherein the S content is 0.005 mass% or less.   3. The copper material for a sputtering target according to claim 1, wherein an area ratio occupied by the additive element and the compound containing S in the same plane as the sputtering surface is 0.4% or less. 4.   Vickers hardness is 80 Hv or less, The copper raw material for sputtering targets as described in any one of Claims 1-3 characterized by the above-mentioned.   The copper material for a sputtering target according to any one of claims 1 to 4, wherein the standard deviation of Vickers hardness measured at a plurality of locations in the same plane as the sputtering surface is 10 or less.   6. The copper material for a sputtering target according to claim 1, wherein an average crystal grain size is 100 μm or less.

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