JP5951599B2 - High purity Ni sputtering target and method for producing the same - Google Patents

Description

  The present invention relates to a high-purity Ni sputtering target and a method for producing the same.

Refractory metal silicide films are widely used as wiring films for semiconductor elements (including liquid crystal display elements). As a method of forming this wiring film, a method of forming a film by sputtering a refractory metal silicide sputtering target has been used.
As a method for manufacturing this type of sputtering target, for example, Japanese Patent Laid-Open No. 2002-38260 (Patent Document 1) discloses that a target is manufactured by sintering silicide such as W, Mo, and Ni. . Such a metal silicide target requires control of the metal silicide and free Si.
On the other hand, in connection with the narrowing and complexity of wiring of semiconductor devices, after forming a metal film, it is attempted to perform a heat treatment to convert the metal film into a metal silicide film. For example, in Japanese Patent Application Laid-Open No. 2009-239172 (Patent Document 2), after forming a metal film such as V, Ti, Co, or Ni, heat treatment is performed at about 400 to 500 ° C. to convert the metal film into a metal silicide film. (Rapid Thermal Annealing) method is disclosed. By this method, a metal silicide film can be formed at a target location.
Ni is attracting attention as a metal used for such a metal silicide film. For example, Japanese Unexamined Patent Application Publication No. 2008-101275 (Patent Document 3) discloses a high purity Ni sputtering target. In Patent Document 3, the uniformity (uniformity) of the sputtered film is improved by controlling the magnetic permeability and coarse grains.
On the other hand, since the target of Patent Document 3 has to have a target thickness of 5 mm or less, long-term sputtering operation cannot be performed, and there is a drawback that the number of replacements of the target is large and the continuous operation characteristics are low.

JP 2002-38260 A JP 2009-239172 A JP 2008-101275 A

When producing a high-purity Ni target having a thickness of 5 mm or more, the problem is crystal orientation. For example, if the crystal orientation of the sputtering surface is different from the crystal orientation of the center portion of the target, the sputtering rate changes, so that there is a problem that stable long-term sputtering characteristics cannot be obtained.
The present invention has been made to solve such problems, and provides a sputtering target with long-term reliability by making the crystal orientation uniform and random.

The first high-purity Ni sputtering target of the present invention is a high-purity Ni sputtering target having an average crystal grain size of 1000 μm or less and a purity of 99.99% by mass or more, and the crystal orientation on the sputtering surface is random orientation. In addition, the crystal orientation in the center plane in the thickness direction of the sputtering target is also random orientation, and when the X-ray diffraction (2θ) peak of the sputter surface and the center plane in the thickness direction is measured, (220), ( 200), is characterized in that (the order of the relative intensity ratio of 111) are both (220) <(200) <(111).
The second high-purity Ni sputtering target of the present invention is a high-purity Ni sputtering target having an average crystal grain size of 1000 μm or less and a purity of 99.99% by mass or more. and the order of the height of each peak detected when a and order of the height of each peak is identical to be detected when the X-ray diffraction by a portion of the target powder, both (220) < (200) <(111) is satisfied.
Furthermore, in the high purity Ni sputtering target, the average crystal grain size is preferably 20 to 500 μm. The average aspect ratio of the crystal grain size of the sputtered surface is preferably 3 or less.
Also, the order of the heights of the peaks detected when X-ray diffraction is performed on the sputtering surface is the same as the order of the heights of the peaks detected when X-ray diffraction is performed with a part of the target powder. It is preferable that
The high purity Ni preferably has a purity of 99.999% by mass or more. Moreover, it is preferable that the thickness of a sputtering target is 6 mm or more. Further, when the X-ray diffraction (2θ) peak of the sputtering surface is measured, the order of the relative intensity ratio of (220), (200), (111) is (220) <(200) <(111). Is preferred.

Moreover, the manufacturing method of the high purity Ni sputtering target of this invention pressurizes the Ni raw material which consists of a cylindrical high purity Ni ingot or billet whose purity is 99.99 mass% or more in a direction parallel to the thickness direction. A first forging process in which cold forging or hot forging and cold or hot forging in which the pressure is applied in a direction perpendicular to the thickness direction are set as one set, and two or more sets of forging are performed;
A first heat treatment step for recrystallization at a temperature of 900 ° C. or higher after the kneading forging step;
After the first heat treatment step, a cold or hot forging process in which pressure is applied in a direction parallel to the thickness direction and a cold or hot forging process in which impact pressing is performed in a direction perpendicular to the thickness direction are combined into one set. A second forging process for forging two or more sets;
After the second kneading forging process, a cold rolling process for performing cold rolling,
A second heat treatment step for heat treatment at a temperature of 500 ° C. or higher after the cold rolling step;
It is characterized by comprising.
Moreover, in the manufacturing method of the said high purity Ni sputtering target, it is preferable to perform the said cold rolling process twice or more. Moreover, it is preferable that at least one of the first kneading forging step and the second kneading forging step is performed at a processing rate with a cross-section reduction rate or a thickness reduction rate of 40% or more. The average value of the Vickers hardness Hv of the Ni alloy material after the first kneading forging is preferably Hv160 or more. The Ni material preferably has a Ni purity of 99.999% by mass or more.

In the high purity Ni sputtering target according to the present invention, since the random crystal orientation is maintained in the thickness direction, the sputtering rate is stable over a long period of time. Therefore, the sputtering process can be efficiently performed because the number of target replacements can be reduced in the sputtering process.
Moreover, according to the manufacturing method of the high purity Ni sputtering target which concerns on this invention, the high purity Ni sputtering target of this invention can be manufactured efficiently.

It is a perspective view which shows the example of a shape of the high purity Ni sputtering target which concerns on this invention. It is a perspective view which shows the example of a shape of columnar Ni raw material. It is a side view which shows the example of a shape which looked at the column-shaped Ni raw material from the horizontal direction. It is a top view which shows the example of a shape which looked at the column-shaped Ni raw material from the top.

The first high-purity Ni sputtering target of the present invention is a high-purity Ni sputtering target having an average crystal grain size of 1000 μm or less, the crystal orientation on the sputtering surface is random orientation, and the thickness direction of the sputtering target is The crystal orientation in the center plane is also random orientation.
The second high-purity Ni sputtering target of the present invention is a high-purity Ni sputtering target having an average crystal grain size of 1000 μm or less, and the height of each peak detected when the sputter surface is diffracted by X-ray diffraction. And the order of the heights of the peaks detected when X-ray diffraction is performed using a part of the target as a powder.
The high purity Ni (nickel) used in the present invention indicates a high purity with a Ni purity of 99.99% by mass or more. Purity measurement methods include Fe, Cr, Al, Co, Ti, Zr, Hf, V, Nb, Ta, Pt, Pb, Cu, Mn, Na, K, S, W, Mo, B as main impurity metals. , P, U, and Th are measured, and Ni purity is determined by subtracting the total amount from 100% by mass. In addition to this, metal impurities are contained, but in most cases, the amount is extremely small so as not to affect the calculation of purity.
In this invention, content of an impurity metal is 0.01 mass% or less (100 wtppm or less), Preferably it is 0.001 mass% or less (10 wtppm or less). The impurity metal content of 0.01% by mass or less means Ni purity of 99.99% by mass or more. The impurity metal content of 0.001% by mass or less means Ni purity of 99.999% by mass or more.
Moreover, an impurity gas component is mentioned as impurities other than an impurity metal. Gas components include oxygen, nitrogen, carbon, and hydrogen. The total amount of these gas components is preferably 300 wtppm or less, more preferably 150 wtpm or less.
When there are many impurity metals and impurity gas components as described above, it causes a partial resistance variation of the target, resulting in a large variation in sputtering rate. Therefore, the above range is preferable.

  Further, the average crystal grain size of the Ni sputtering target is 1000 μm or less. When the average crystal grain size exceeds 1000 μm, Ni (including Ni alloy) crystals become excessive, which causes variations in the sputtering rate. Preferably, the average crystal grain size is 20 to 500 μm, more preferably 40 to 500 μm, and further preferably 40 to 120 μm. As a method for controlling the average crystal grain size, recrystallization by heat treatment is also effective.

The average crystal grain size is measured by taking a magnified photograph of a unit area of 3000 μm × 3000 μm with an optical micrograph and using the line intercept method. In the line intercept method, an arbitrary straight line (for a length of 3000 μm) is drawn, the number of Ni crystal grains on the line is counted, and the average crystal grain size is determined by (3000 μm / the number of crystals on a straight line 3000 μm). The average value obtained by performing this operation three times is defined as the average crystal grain size.
Moreover, it is preferable that the average aspect ratio of the crystal grain diameter of the sputtering surface of the Ni sputtering target is 3 or less. When the average aspect ratio exceeds 3, there is a possibility that a portion that is not randomly oriented is formed on the sputtering surface. The average aspect ratio is preferably 3 or less, more preferably 2 or less.
The average aspect ratio is measured using the magnified photo used to measure the average grain size, measuring the major and minor axes of each crystal grain, and determining the aspect ratio (major / minor axis). Ask. This work was performed on 100 pieces of crystal grains, and the average value of the "average aspect ratio". Further, the major axis is the maximum diameter of the crystal grains, and the minor axis is the width of a portion drawn vertically from the center of the major axis.

The high-purity Ni sputtering target according to the first invention is characterized in that the crystal orientation of the sputtering surface is random, and the crystal orientation in the center plane in the thickness direction of the target is also random.
FIG. 1 shows an example of the shape of the sputtering target of the present invention. In the figure, 1 is a sputtering target, 2 is a sputtering surface, and T is the thickness of the target. In FIG. 1, a cylindrical (disc-shaped) target is used, but a rectangular parallelepiped may be used. Even if it is a cylindrical shape or a rectangular parallelepiped shape, it may be chamfered if necessary.
In the high purity Ni sputtering target 1 according to the first invention, the crystal orientation of the sputtering surface 2 is random orientation. Further, the crystal orientation of the center plane 4 in the thickness direction of the target also shows random orientation. The “center plane in the thickness direction of the target” is a plane cut in parallel with the sputtering surface from the middle (T / 2 position) of the target thickness T, as indicated by a dotted line in FIG. The high purity Ni sputtering target 1 is manufactured by performing plastic working such as forging and rolling.
When plastic processing is performed on a metal material, crystals are easily oriented. On the other hand, a phenomenon in which crystal orientation differs between the sputter surface and the inside tends to occur. On the other hand, in the present invention, since the sputtering surface is randomly oriented and the center of the target is also randomly oriented, it is difficult for the sputtering rate to change even when used continuously for a long time.
When the crystal orientation of the center plane 4 in the target thickness direction is also random, the same random orientation can be obtained by cutting out a plane parallel to the sputtering surface at the center in the target thickness direction and performing X-ray diffraction. I can confirm.

The second high-purity Ni sputtering target of the present invention is a high-purity Ni sputtering target having an average crystal grain size of 1000 μm or less, and the order of the height of each peak detected when the sputter surface is X-ray diffracted. The order of the heights of the peaks detected when X-ray diffraction is performed using a part of the target as powder is the same.
The order of the height of each peak detected when X-ray diffraction is performed on the sputtering surface is the same as the order of the height of each peak detected when X-ray diffraction is performed with a part of the target powder. This indicates that the entire target has a uniform random orientation.

As conditions for the X-ray diffraction, the X-ray used is Cu-Kα, the tube voltage is 40 kV, the tube current is 40 mA, the scattering slit is 0.63 mm, and the light receiving slit is 0.15 mm. The following general conditions are used for trial purposes.
If the orientation is random when X-ray diffraction of the sputtering surface is taken, the result of the relative intensity ratio (peak height) order is (220) <(200) <(111).
Further, X-ray diffraction performed using a part of the target as powder is performed according to the following procedure. That is, a rectangular parallelepiped of at least 5 mm square is cut out from an arbitrary portion of the target and pulverized so that the average particle diameter becomes 50 to 100 μm. The pulverized powder is subjected to X-ray diffraction to obtain an X-ray diffraction peak (PDF peak) of the powder. The X-ray diffraction measurement conditions are the same as described above.

In the present invention, the order of the peak height of the sputtering surface is the same as the order of the height of the PDF peak. Although the ratio of the heights of the individual peaks may differ between the sputter surface and the PDF (powder), the order of the detected peak heights matches. As described above, the peak order of the sputtering surface is (220) <(200) <(111), and this order is maintained even when the order becomes powder (PDF peak). The fact that the random orientation is maintained even in the powder proves that the uniform random orientation is maintained throughout the target.
Further, the order of peak height (220) <(200) <(111) in X-ray diffraction is the same as the peak order of commercially available Ni powders. From this point, it can be said that the orientation is random.
In addition, the random orientation anywhere on the sputtering surface means that a fine crystal structure free from ghost grains in which the cast structure remains can be formed. The presence of ghost grains is not preferable because a portion that is not partially in random orientation is formed.

In the present invention, a target having a stable sputtering rate for a long period of time can be obtained even if the thickness of the target is increased to 3 mm or more, and further to 6 mm or more. The upper limit of the target thickness is not particularly limited, but is preferably 15 mm or less. If it exceeds 15 mm, it becomes too thick and the handleability deteriorates. Also, the diameter of the target is not particularly limited, but uniform random orientation can be obtained even if the diameter is increased to 200 mm or more, and further to 400 mm or more. The upper limit of the target diameter is not particularly limited, but is preferably 600 mm or less. When it exceeds 600 mm, the handleability deteriorates.
Moreover, you may join a backing plate to the sputtering target of this invention as needed.

Next, a manufacturing method will be described. Although the manufacturing method of the high purity Ni sputtering target of this invention is not specifically limited, The following manufacturing method is mentioned as a method for obtaining efficiently.
The manufacturing method of the high purity Ni sputtering target of the present invention includes a cold or hot forging process in which a Ni material made of a cylindrical high purity Ni ingot or billet is pressed in a direction parallel to the thickness direction and in the thickness direction. The first kneading forging process in which two or more sets of cold forging or hot forging processing in which pressure is applied in the vertical direction is set, and the first recrystallization at a temperature of 900 ° C. or more after the kneading forging process. After the first heat treatment step, cold or hot forging process in which pressure is applied in a direction parallel to the thickness direction and cold or hot forging process in which impact pressure is applied in a direction perpendicular to the thickness direction are performed. After the second kink forging process in which two or more sets of kneading and forging are performed, a cold rolling process in which cold rolling is performed after the second kink forging process, and after the cold rolling process, 5 A second heat treatment step of heat-treating at 0 ℃ temperatures above is characterized in that it comprises a.
The Ni material made of the columnar high-purity Ni ingot or billet is, for example, a Ni material having a columnar shape as shown in FIG. FIG. 3 shows the thickness H and the diameter W of the cylindrical Ni material 3. The size of the columnar Ni material 3 is not particularly limited, but those having a thickness H of about 20 to 300 mm and a diameter W of about 100 to 400 mm are easy to handle. The Ni material is preferably purified by casting such as an EB (electron beam) melting method. Moreover, you may implement EB melt | dissolution 2 to 3 times as needed. This is because the purity of the Ni material is close to the purity of the high-purity Ni target. Therefore, when a Ni target with a purity of 99.99 wt% or more (4N or more) is required, a high-purity Ni material with a purity of 99.99 wt% or more is used.

Cold forging or hot forging for pressing a cylindrical Ni material in a direction parallel to the thickness direction and cold or hot forging for pressing in a direction perpendicular to the thickness direction as one set. The first kneading forging process in which two or more sets are performed. The direction parallel to the thickness direction is the thickness H direction, and the direction perpendicular to the thickness direction is the diameter W direction.
When the forging is alternately forged in the thickness H direction and the diameter W direction, two or more sets are performed. In the kneading forging, since pressure is applied from different directions, the crystal grain size can be reduced and the crystal orientation can be prevented from being biased in a specific direction. In addition, the cast structure of Ni material produced by casting can be reduced. The larger the number of times of kneading and forging, the better. However, if the number of times is too large, the manufacturing cost is increased, and cracking and wrinkling of the material are likely to occur.

  Moreover, it is preferable that the Vickers hardness Hv of the Ni material after the first kneading forging step is 160 or more. By performing two or more sets of the above forging, the structure can be homogenized and the hardness of the Ni material can be increased. However, when considering the manufacturing process described later, even if it is less than Hv160, no further effect is obtained, and the kneading forging process is wasted. Therefore, in order to control the number of sets of the first kneading forging, it is preferable to perform the kneading forging so that the Vickers hardness is Hv160 or more.

  Also, the pressure in the diameter W direction is not always constant as shown in FIG. 4, and the first set applies pressure from the direction of “pressure 2”, while the second set starts from the direction of “pressure 3”. It is preferable to change the pressing direction as appropriate, such as by applying pressure. It is also effective to change the direction in which pressure is applied in one set. By changing the direction in which the pressure is applied also in the diameter W direction, it is possible to reduce the crystal grain size and effectively prevent the crystal orientation from being biased in a specific direction. The first kneading forge is preferably cold forging, but hot forging is also possible. The heating temperature in the case of hot forging is preferably in the range of 1000 to 1200 ° C. In addition, since crystal grain growth occurs, it is difficult to obtain a fine crystal structure having an average crystal grain size of 1000 μm or less.

  After the first kneading forging step, a first heat treatment step for recrystallization at a temperature of 900 ° C. or higher is performed. In the first kneading forging process, internal strain generated in the columnar Ni material can be removed by heat treatment and recrystallized to obtain a uniform fine crystal structure. The heat treatment temperature is preferably 950 to 1300 ° C. and is preferably performed for 1 to 10 hours. When the heat treatment temperature exceeds 1300 ° C. or the heat treatment time exceeds 10 hours, there is a risk of accompanying grain growth. Preferably it is 1000-1200 degreeC x 3-7 hours. The heat treatment atmosphere is preferably a vacuum atmosphere of 0.133 Pa or less. This is because the surface may be oxidized during the heat treatment in an oxygen-containing atmosphere.

  After the first heat treatment step, second kneading forging is performed. The details of the kneading forging are the same as those of the first kneading forging, and it is preferable to perform two or more sets. The second kneading forging is also preferably 2 to 4 times. In addition, it is preferable to change the pressure direction applied in the diameter W direction between the first set and the second set. Moreover, it is preferable that the second kink forging process is also cold forging, but hot forging is also possible. The second kneading forging can further refine the crystal grain size.

After the second kneading forging, a cold rolling process is performed. Cold rolling is a process of plastic processing a cylindrical Ni material into a plate shape. If necessary, the cold rolling step may be performed twice or more. It is desirable that the thickness be 3 to 20 mm, preferably 6 to 15 mm, by a cold rolling process. Cutting is performed from the plate thickness prepared by the cold rolling process to obtain the plate thickness of the sputtering target.
Moreover, it is better not to perform the heat treatment step between the second kneading forging step and the cold rolling step. It is preferable to cold-roll the Ni material homogenized by the second kneading forging process as it is.
The processing rates of the first kneading forging step, the second kneading forging step, and the cold rolling step are arbitrary, but at least one of the first kneading forging step, the second kneading forging step, and the cold rolling step. It is preferable that the cross-section reduction rate or the thickness reduction rate of one process is 40% or more. The cross-section reduction rate is the reduction rate of the cross-sectional area in the diameter W direction of the cylindrical Ni material. The thickness reduction rate is a reduction rate in the thickness H direction of the cylindrical Ni material. For example, two or more sets of the first kneading forging process are performed. The processing rate of 40% or more is the processing rate obtained as a result of one set.

The process with a processing rate of 40% or more is preferably a cold process. For example, the occurrence of internal strain can be suppressed even after cold rolling with a processing rate of 40% or more is performed after the first kneading forging step → first heat treatment step → second kneading forging step. . When the processing rate is low, the occurrence of internal strain can be suppressed, but each process is repeated many times, and the manufacturing time is too long. Therefore, it is preferable to perform a process with a processing rate of 40% or more in some process. The upper limit of the processing rate is preferably 80% or less. When processing at a processing rate exceeding 80% in one process, internal distortion, cracks, wrinkles and the like are likely to occur.
After the cold rolling step, a second heat treatment step is performed in which heat treatment is performed at a temperature of 500 ° C. or higher. The heat treatment conditions are preferably 500-1100 ° C. × 2-5 hours. The heat treatment atmosphere is preferably a vacuum atmosphere of 0.133 Pa or less. This is because the surface may be oxidized during the heat treatment in an oxygen-containing atmosphere. By the second heat treatment step, the internal strain generated by the second kneading forging step and the cold rolling step can be removed and recrystallized.

After the second heat treatment step, the shape is adjusted by cutting such as lathe as necessary. Further, the backing plate is joined by brazing material joining or diffusion joining.
With such a manufacturing method, an average crystal grain size of 1000 μm or less and a fine crystal structure and random orientation can be obtained simultaneously. In addition, the formation of ghost grains in which the cast structure remains can be suppressed.

Next, a method for manufacturing a semiconductor element will be described. A method of manufacturing a semiconductor device includes a step of sputtering a high-purity Ni sputtering target of the present invention on a film containing Si as a constituent element to form a high-purity Ni thin film, and performing heat treatment to convert the high-purity Ni thin film into Ni silicide. And a step of forming a film.
Examples of the film containing Si as a constituent element include a Si substrate and a gate electrode (polycrystalline Si, amorphous Si, etc.). A high purity Ni film is formed on a film containing Si as a constituent element by magnetron sputtering using the high purity Ni sputtering target of the present invention. Next, an RTA (Rapid Thermal Annealing) process is performed by heat-treating at about 400 to 500 ° C. to react the high-purity Ni film with Si to form a Ni silicide film.
Depending on the degree of heat treatment, part or all of the Ni film becomes a Ni silicide film. The Ni silicide film is preferably used for part or all of the gate electrode, source electrode, and drain electrode.
By using the high-purity Ni sputtering target of the present invention, the sputtering rate can be stabilized for a long period of time, so that a stable high-purity Ni film can be obtained when manufacturing a semiconductor element. Even if the target thickness is increased, the fluctuation of the sputtering rate is small and the number of target replacements can be reduced, so that the manufacturing efficiency of the semiconductor element can be greatly improved.

(Example)
(Examples 1-6 and Comparative Example 1)
A high-purity Ni material having a diameter of W100 to 300 mm and a thickness of H100 to 200 mm, which was highly purified by EB melting, was prepared and subjected to the manufacturing process shown in Table 1. In Table 1, the processing rate (%) indicates the larger value of at least one of the cross-section reduction rate (%) in the diameter W direction and the thickness reduction rate (%) in the thickness H direction.
Further, the Ni material was oxygen 20 wtppm or less, nitrogen 10 wtppm or less, carbon 10 wtppm or less, and the content of impurity metals was 10 wtppm or less in total.

A high-purity Ni material that had undergone the manufacturing steps shown in Table 1 above was turned to prepare sputtering targets having the sizes shown in Table 2. The average crystal grain size (μm) and presence / absence of random orientation in each target were confirmed. The average crystal grain size was measured by taking an enlarged photograph (photomicrograph) having a unit area of 3000 μm × 3000 μm from the sputtered surface and the cross section, and by the line intercept method (average value of three straight lines). Regarding the measurement of Ni crystal grains, the aspect ratio of 100 grains was obtained from the above-mentioned enlarged photograph, and the average value was shown. The presence or absence of random orientation was determined by selecting an arbitrary measurement location from the sputter surface and a surface parallel to the sputter surface at the center of the target thickness from the sputter surface and performing X-ray diffraction analysis (2θ). X-ray diffraction was performed with Cu-Kα (target Cu), tube voltage 40 kV, tube current 40 mA, scattering slit 0.63 mm, and light receiving slit 0.15 mm.
The analysis results are shown in Table 2. All crystal structures were recrystallized.

  Further, a sample of 5 mm square was cut out from the target and pulverized so as to have an average particle diameter of 80 μm, followed by X-ray diffraction to obtain the order of detected peaks. The results are shown in Table 3.

実施例７〜１０に係るＮｉスパッタリングターゲットに関して、実施例１と同様の測定を行った。その結果を表５に示す。

また、ターゲットから５ｍｍ角の試料を切り出し平均粒径８０μｍになるように粉砕してＸ線回折を行い検出されるピークの順番を求めた。その結果を表６に示す。

表５と表６とを比較すると検出されるピークの順番は一致した。また、（２２０）＜（２００）＜（１１１）のピーク順は市販のＮｉ粉末のピーク順とも一致する。
次に各実施例および比較例のターゲットを用いてマグネトロンスパッタ工程を行った。スパッタ開始後からターゲットが０．５ｍｍ消費されたときのＮｉ膜厚を１００としたとき、２ｍｍ消費後と５ｍｍ消費後の膜厚を比較した。 Comparing Table 2 and Table 3, the order of detected peaks was the same. In addition, the peak order of (220) <(200) <(111) matches the peak order of commercially available Ni powder.
(Examples 7 to 10)
A high-purity Ni material having a diameter of 200 to 300 mm and a thickness of H100 to 150 mm, which has been highly purified by EB melting, was prepared and subjected to the manufacturing steps shown in Table 4 below. In Table 4, the processing rate (%) is the larger value of at least one of the cross-sectional reduction rate (%) in the diameter W direction and the thickness reduction rate (%) in the thickness H direction.
Further, the Ni material had an oxygen content of 20 wtppm or less, a nitrogen content of 10 wtppm or less, a carbon content of 10 wtppm or less, and the content of impurity metals was 10 wtppm or less in total.

Regarding the Ni sputtering target according to Examples 7 to 10, the same measurement as in Example 1 was performed. The results are shown in Table 5.

Further, a sample of 5 mm square was cut out from the target and pulverized so as to have an average particle diameter of 80 μm, followed by X-ray diffraction to obtain the order of detected peaks. The results are shown in Table 6.

When comparing Table 5 and Table 6, the order of the peaks detected was the same. In addition, the peak order of (220) <(200) <(111) matches the peak order of commercially available Ni powder.
Next, a magnetron sputtering process was performed using the targets of the examples and comparative examples. The film thickness after consumption of 2 mm and after consumption of 5 mm was compared with the Ni film thickness when the target was consumed 0.5 mm after the start of sputtering.

  As is clear from the results shown in Table 7, it was found that the target according to each example had a small change in sputtering rate even when used for a long time. From this result, it can be seen that the target of this example has high long-term reliability even when the thickness is increased.

DESCRIPTION OF SYMBOLS 1 ... Sputtering target 2 ... Sputtering surface 3 ... Ni material T ... Sputtering target thickness W ... Ni material diameter H ... Ni material thickness (height)

Claims (14)

A high-purity Ni sputtering target having an average crystal grain size of 1000 μm or less and a purity of 99.99% by mass or more, the crystal orientation on the sputtering surface is random orientation, and the center plane in the thickness direction of the sputtering target The crystal orientation in is also a random orientation, and when the X-ray diffraction (2θ) peak of the sputter surface and the central surface in the thickness direction is measured, the order of the relative intensity ratio of (220), (200), (111) is Both high-purity Ni sputtering targets, wherein (220) <(200) <(111). A high-purity Ni sputtering target having an average crystal grain size of 1000 μm or less and a purity of 99.99% by mass or more, and the order of the height of each peak detected when the sputter surface is X-ray diffracted; and a portion of the target are identical and the order of the height of each peak in the powder is detected when the X-ray diffraction, and satisfies both (220) <(200) <(111) High purity Ni sputtering target.   The high-purity Ni sputtering target according to claim 1 or 2, wherein the average crystal grain size is 20 to 500 µm.   4. The high-purity Ni sputtering target according to claim 1, wherein an average aspect ratio of a crystal grain size of the sputter surface is 3 or less. 5.   The order of the height of each peak detected when X-ray diffraction is performed on the sputtering surface is the same as the order of the height of each peak detected when X-ray diffraction is performed with a part of the target powder. The high-purity Ni sputtering target according to any one of claims 1 to 4, wherein the high-purity Ni sputtering target is characterized.   The high-purity Ni sputtering target according to any one of claims 1 to 5, wherein the high-purity Ni has a purity of 99.999% by mass or more.   The high-purity Ni sputtering target according to any one of claims 1 to 6, wherein the sputtering target has a thickness of 6 mm or more. A cold or hot forging process in which a Ni material made of a cylindrical high-purity Ni ingot or billet having a purity of 99.99% by mass or more is pressed in a direction parallel to the thickness direction and a direction perpendicular to the thickness direction A first forging process in which at least two sets of cold forging or hot forging processing to pressurize are performed and two or more sets of forging are performed;
A first heat treatment step for recrystallization at a temperature of 900 ° C. or higher after the kneading forging step;
After the first heat treatment step, a cold or hot forging process in which pressure is applied in a direction parallel to the thickness direction and a cold or hot forging process in which impact pressing is performed in a direction perpendicular to the thickness direction are combined into one set. A second forging process for forging two or more sets;
After the second kneading forging process, a cold rolling process for performing cold rolling,
A second heat treatment step for heat treatment at a temperature of 500 ° C. or higher after the cold rolling step;
The manufacturing method of the high purity Ni sputtering target characterized by comprising. The method for producing a high-purity Ni sputtering target according to claim 8, wherein the cold rolling step is performed twice or more. Wherein at least one of the first Konekuri forging step and second Konekuri forging process, according to claim 8 or claim 9, characterized in that reduction of area or thickness reduction rate is performed at 40% or more working ratio The manufacturing method of the high purity Ni sputtering target of any one of Claims 1. Production of high-purity Ni sputtering target according to any one of claims 8 to 10 the average value of the first Konekuri Vickers hardness Hv of Ni alloy material after forging is characterized in that at Hv160 or more Method. The method for producing a high-purity Ni sputtering target according to any one of claims 8 to 11 , wherein the Ni material has a Ni purity of 99.999 mass% or more. The method for producing a high purity Ni sputtering target according to any one of claims 8 to 12 , wherein the obtained high purity Ni sputtering target has an average crystal grain size of 1000 µm or less. The resulting high-purity Ni sputtering target of high purity Ni sputtering target according to any one of claims 8 to 13, wherein an average aspect ratio of crystal grains of the sputtering surface is 3 or less Production method.

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