JP4007010B2 - Sputtering target - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sputtering target made of a magnetic material suitable for use in a magnetron discharge type sputtering apparatus.
[0002]
[Prior art]
Conventionally, as this type of sputtering target, the one shown in FIGS. 7 and 8 is known (see, for example, JP-A-6-264218).
[0003]
A backing plate 3 is provided on the support member 1 via a magnetic field generator 2, and a sputtering target 4 made of a magnetic material is mounted on the surface of the backing plate 3. The magnetic field generator 2 includes a permanent magnet 2a disposed in the center of the backing plate 3 so that the backing plate 3 side becomes the S pole, and surrounds the permanent magnet 2a in a square frame shape, and the backing plate 3 side has the N pole. And a permanent magnet 2b arranged in such a manner. In the sputtering target 4, a groove 4A having a depth of about 3 mm is formed on the sputtering surface in a square frame shape corresponding to the space between the magnets 2a and 2b in order to increase the leakage magnetic flux.
[0004]
FIGS. 9 and 10 show another example of a conventional sputtering target made of a magnetic material, and the same parts as those in FIGS. The sputtering target 5 in FIG. 9 is different from the sputtering target 4 in FIG. 7 in that there is no groove corresponding to 4A. Moreover, the sputtering target 6 in FIG. 10 differs from the sputtering target 4 in FIG. 7 in that there is no groove corresponding to 4A and that the shape is circular.
[0005]
[Problems to be solved by the invention]
According to the sputtering target shown in FIGS. 9 and 10, since the magnetic flux concentrates on the sputtering surface at a location corresponding to the space between the magnets 2a and 2b, erosion (self-sputtering by a magnetic field) proceeds to form erosion grooves 5a and 6a. Is done. As a result, the target life is shortened. In addition, since a part of the target is intensively hit by ions, the sputter particle size becomes uneven, and the uniformity of the sputter composition and the film thickness distribution is lowered.
[0006]
On the other hand, according to the sputtering target of FIGS. 7 and 8, since discharge plasma acts intensively on the groove 4A, high-speed sputtering is possible, but it is inevitable that erosion proceeds in the groove 4A. For this reason, the problem that the target life is shortened and the sputter particle size becomes uneven is inevitable.
[0007]
An object of the present invention is to provide a novel sputtering target capable of achieving an extension of the target life and an improvement in the uniformity of the sputtering composition and film thickness distribution.
[0008]
A sputtering target according to the present invention is a sputtering target made of a magnetic material to which a magnetic field is applied via a backing plate, and a magnetic flux leakage groove is formed in the vicinity of a magnetic flux concentration region where erosion grooves are expected to be formed on the sputtering surface. The plurality of grooves are arranged in parallel on one side and the other side of the magnetic flux concentration region, respectively, and the plurality of parallel grooves are farther from the magnetic flux concentration region than the grooves near the magnetic flux concentration region. The groove is formed deeply .
[0009]
According to the sputtering target of the present invention, since the magnetic flux leakage groove is provided in the vicinity of the magnetic flux concentration region where erosion grooves are expected to be formed on the sputtering surface, the discharge plasma is used not only for the magnetic flux concentration region but also for magnetic flux leakage. It also acts on the groove and its vicinity, and the sputter area is expanded. For this reason, the target can be consumed uniformly and the life of the target is extended. Also, the sputter particle size becomes uniform, and the uniformity of the sputter composition and the sputter film thickness distribution are improved.
[0010]
The sputtering target of the present invention, a groove for each magnetic flux leaking to the one side and the other side of the magnetic flux concentration regions plurality juxtaposed, the magnetic flux from the groove close to the area of magnetic flux concentration when multiple parallel grooves for magnetic flux leakage distant grooves in concentration region formed deeply. In this way, the sputtering area is further expanded, and the uniformity of target consumption is further improved.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2 show a sputtering target according to an embodiment of the present invention, and FIG. 1 shows a cross section taken along line AA ′ of FIG.
[0012]
A magnetic field generator 10 is provided on one main surface of the backing plate 12 made of a conductive material such as Cu, and a sputtering target 14 made of a magnetic material such as Fe is provided on the other main surface of the backing plate 12. It has been. The magnetic field generator 10 includes a permanent magnet 10a disposed in the center of the backing plate 12 so that the backing plate 12 side has an N pole, and surrounds the permanent magnet 10a in a square frame shape, and the backing plate 12 side has an S pole. The permanent magnet 10b is arranged so as to be. A magnetic field is applied to the sputtering target 14 from the magnetic field generator 10 through the backing plate 12 so that the magnetic flux distribution is indicated by a broken line M.
[0013]
On the sputtering surface of the sputtering target 14, magnetic flux leakage grooves 16, 18, 20, 22 correspond to the four outer walls of the magnet 10 a inside the magnetic flux concentration region 14 a where erosion grooves are expected to be formed. At the same time, grooves 24, 26, 28 and 30 for magnetic flux leakage are formed outside the magnetic flux concentration region 14a so as to correspond to the four inner walls of the magnet 10b. About the grooves 16-30, the depth D can be about 0.2-0.6 mm. The grooves 16 to 30 can be formed by cutting or the like.
[0014]
Since the grooves 16 to 30 are provided, the conductive plasma acts not only on the magnetic flux concentration region 14a but also on the magnetic flux leakage grooves 16 to 30 and the vicinity thereof, and the sputtering area is expanded. For this reason, the target 14 can be uniformly consumed, and the target life is extended. In addition, the sputter particle size becomes uniform, and the uniformity of the sputter composition and film thickness distribution is improved.
[0015]
3 and 4 show a sputtering target according to another embodiment of the present invention, and FIG. 3 shows a cross section taken along line BB ′ of FIG. 3 and 4, parts similar to those in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted. The sputtering target 14 in FIGS. All of the grooves 16 to 30 correspond to two grooves. That is, four sets of magnetic flux leakage grooves 16a-16b, 18a-18b, 20a-20b, and 22a-22b are formed on the four outer walls of the magnet 10a inside the magnetic flux concentration region 14a where erosion grooves are expected to be formed. And four sets of magnetic flux leakage grooves 24a-24b, 26a-26b, 28a-28b, 30a-30b on the four inner side walls of the magnet 10b on the outside of the magnetic flux concentration region 14a. Each is provided correspondingly. The two grooves of each set for magnetic flux leakage are formed so as to extend substantially in parallel.
[0016]
FIG. 5 shows a modification of the sputtering target of FIGS. 3 and 4, and parts similar to those of FIGS.
[0017]
The sputtering target 14 of FIG. 5 forms a groove farther from the magnetic flux concentration region 14a than the groove closer to the magnetic flux concentration region 14a among the two grooves of each set for magnetic flux leakage in the sputtering target described above with reference to FIGS. Is equivalent to That is, the grooves 16b to 30b are formed deeper than the grooves 16a to 30a. For grooves 16A～30a, depth _{D 1} is, it is possible to 0.2 to 0.6 mm, for groove 16B～30b, the depth _{D 2} may be a 0.6~0.7mm .
[0018]
FIG. 6 shows another modification of the sputtering target of FIGS. 3 and 4, and parts similar to those of FIGS.
[0019]
The sputtering target 14 shown in FIG. 6 corresponds to the sputtering target described above with reference to FIGS. 3 and 4 in which each set of two grooves for magnetic flux leakage is divided into a plurality of pieces. That is, the grooves 16a, 16b, 20a, 20b, 24a, 24b, 28a, 28b are divided into two for each group, and the grooves 18a, 18b, 22a, 22b, 26a, 26b, 30a, 30b Each is divided into three.
[0020]
According to the sputtering target described above with reference to FIGS. 3 to 6, the sputtering area is further increased as compared with the sputtering target described above with reference to FIGS. Accordingly, the target life is further extended, and the uniformity of the sputter composition and the film thickness distribution is further improved.
[0021]
As described above, according to the present invention, the sputtering target having a groove for the magnetic flux leaking in the vicinity of the area of magnetic flux concentration to formation of d Rojon grooves on the sputter surface of the sputtering target made of a magnetic material is expected, the flux A plurality of the grooves are arranged side by side on one side and the other side of the concentration region, and the plurality of the grooves arranged in parallel are deeper in the magnetic flux concentration region than the grooves near the magnetic flux concentration region. As a result, it is possible to achieve the effect of extending the life of the target and improving the uniformity of the sputter composition and the film thickness distribution.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a sputtering target according to an embodiment of the present invention.
FIG. 2 is a plan view showing a sputtering surface of the sputtering target of FIG.
FIG. 3 is a cross-sectional view showing a sputtering target according to another embodiment of the present invention.
4 is a plan view showing a sputtering surface of the sputtering target of FIG. 3. FIG.
FIG. 5 is a cross-sectional view showing a modification of the sputtering target of FIGS.
6 is a cross-sectional view showing another modification of the sputtering target of FIGS. 3 and 4. FIG.
FIG. 7 is a perspective view showing an example of a conventional sputtering target.
8 is a cross-sectional view taken along line XX ′ of FIG.
FIG. 9 is a partial cross-sectional perspective view showing another example of a conventional sputtering target.
FIG. 10 is a partial cross-sectional perspective view showing still another example of the conventional sputtering target.
[Explanation of symbols]
10: Magnetic field generator, 12: Backing plate, 14: Sputtering target, 14a: Magnetic flux concentration area, 16-30, 16a-30a, 16b-30b: Groove for magnetic flux leakage.

Claims (2)

In a sputtering target made of a magnetic material to which a magnetic field is applied via a backing plate, wherein a magnetic flux leakage groove is provided in the vicinity of a magnetic flux concentration region where erosion grooves are expected to be formed on the sputtering surface .
A plurality of the grooves are arranged in parallel on one side and the other side of the magnetic flux concentration region,
The sputtering target characterized in that the plurality of grooves arranged in parallel are formed deeper in the magnetic flux concentration region than in the magnetic flux concentration region . The sputtering target according to claim 1, wherein the plurality of parallel grooves are divided into a plurality of grooves .

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