JP4965479B2 - Sputtering target manufacturing method and sputtering target cleaning method - Google Patents

Description

  The present invention relates to a sputtering target manufacturing method, a sputtering target cleaning method, a sputtering target, and a sputtering apparatus that can suppress generation of particles generated due to adhesion of a sputtered material.

  One of the methods for forming a high quality metal film is a magnetron sputtering method. In the sputtering method, generally, argon gas plasma is generated in a vacuum, argon (Ar) ions collide with a target fixed to a cathode electrode, and sputtered particles including target atoms scattered from the surface of the target are formed. This is a film forming method for depositing on a substrate to be formed. The magnetron sputtering method is a film forming method that further increases the film forming speed by forming a magnetic field on the target surface and generating high-density plasma near the target.

  Generally, the target is bonded onto a backing plate that is a cathode electrode. In the magnetron sputtering method, a permanent magnet or an electromagnet for forming a magnetic field on the target surface is disposed on the back side of the backing plate. Typically, the magnets are arranged such that the magnetic field is larger in the intermediate part and the intermediate part of the peripheral part than in the central part and the peripheral part of the target. In this case, the sputtering efficiency is high in the intermediate region of the target and is small in the central portion and the peripheral portion of the target. A region with high sputtering efficiency is subjected to a larger erosion action than a region with low sputtering efficiency. Usually, a region with high sputtering efficiency is called an erosion region (erosion region), and a region with low sputtering efficiency is called a non-erosion region (non-erosion region) (see Patent Document 1).

  In this magnetron sputtering method, sputtered particles from the erosion region are deposited on the substrate to form a thin film. On the other hand, some of the sputtered particles are deposited also in the non-erosion region of the target surface. In this case, the deposit on the non-erosion region increases in thickness with the progress of sputtering, and is peeled off from the target surface by its own internal stress. If the deposit peeled off from the target surface is mixed as a foreign substance (particle) in the thin film formed on the substrate, a serious quality defect may be caused.

  As a solution to this problem, a method has been proposed in which the non-erosion region of the target is roughened by blasting to increase the adhesion of deposits. For example, Patent Document 2 describes that the number of batches that can be continuously produced is increased by blasting the target surface. Patent Document 3 discloses more effective hardness and particle size of the blast material when blasting the target surface.

JP-A-7-90576 Japanese Patent Laid-Open No. 4-301074 JP-A-7-316804

  However, there is a problem that merely blasting the non-erosion region of the target is insufficient to suppress the separation of deposits from the target surface.

  In other words, the blast treatment on the target surface suppresses the separation of the deposit attached to the target surface and reduces the generation of steady particles, but the adhesion of the deposit to the target surface is not stable. In many cases, a large amount of particles suddenly occur. The suddenly generated particles have a significant effect on the film quality, resulting in a problem that the yield is lowered.

  In view of the circumstances as described above, an object of the present invention is to reduce the generation of sudden particles and realize improvement of film quality and thin film production efficiency, sputtering target cleaning method, sputtering target cleaning method, and sputtering. The object is to provide a target and a sputtering apparatus.

  In solving the above problems, the present inventors have intensively studied, and as a result, a large amount of particles suddenly generated is caused by the separation of deposits adhering to the blast material remaining on the target surface. The headline and the present invention were completed.

  That is, the sputtering target manufacturing method of the present invention is a sputtering target manufacturing method for a magnetron sputtering apparatus, which prepares a target body, blasts a non-erosion region on the surface of the target body, and forms the non-erosion region. Ultrasonic cleaning is performed, and the non-erosion region that has been ultrasonically cleaned is etched or jet-cleaned with a cleaning liquid, and the non-erosion region is ultrasonically cleaned again.

  In the present invention, after blasting a non-erosion region (blasting region) on the surface of the target body, first, the surface of the target body is cleaned by ultrasonic cleaning. Thereby, among the blast materials remaining in the non-erosion region, it is possible to remove blast materials having relatively weak adhesion to the target body.

  Here, the “non-erosion region” means a region other than the erosion region that appears during actual use of the sputtering target according to the present invention. The same applies to the following description. The non-erosion region is not limited to the surface portion to which the erosion region of the sputtering target belongs, and may include the side surface of the sputtering target.

  Next, the ultrasonically cleaned non-erosion region is etched or jet cleaned. This process is performed by melting a small amount of the boundary portion between the blast material and the target body by an etching process, or by applying a physical impact to the blast material by jet cleaning, so that the blast material remaining in the non-erosion region and the target body. We weaken adhesion between.

  Thereafter, the non-erosion region is ultrasonically cleaned again. As a result, it is possible to easily remove the blast material having a weak adhesion to the target body.

  By the above series of treatments, the efficiency of removing the blast material remaining in the non-erosion region of the target body is increased, so that a sputtering target having a clean surface-state non-erosion region can be obtained. Thereby, it is possible to suppress the generation of a sudden large amount of particles due to the blast material remaining in the non-erosion region, and to form a stable thin film forming process and a high-quality sputtered thin film.

  In the present invention, the blasting step roughens the surface roughness (arithmetic average surface roughness: Ra) of the non-erosion region to 1 μm or more and 4 μm or less. This is because when Ra is less than 1 μm, there is almost no effect by the blast treatment, and when Ra exceeds 4 μm, the difference in height of the target surface becomes too large and the deposit adhesion decreases.

  In the present invention, in the step of ultrasonically cleaning the non-erosion region, the non-erosion region is cleaned with a jet of cleaning liquid to which an ultrasonic wave having a frequency of 18 kHz to 19 kHz is applied. This is because the cleaning liquid to which ultrasonic waves in the above frequency range are applied has a high cleaning effect due to the occurrence of cavitation.

  Also, the sputtering target cleaning method of the present invention is a sputtering target cleaning method in which at least a part of the surface is subjected to blasting, wherein the blasting region of the sputtering target is ultrasonically cleaned, and the ultrasonic cleaning is performed. The blasted region is etched or jet cleaned with a cleaning solution, and the blasted region is ultrasonically cleaned again.

  The sputtering target manufactured or cleaned as described above constitutes a target body, a part of the surface of the target body, an erosion region eroded by sputtering, and another part of the surface of the target body. And a non-erosion region having a surface roughness (Ra) of 1 μm or more and 4 μm or less and a number of blast materials having a circle equivalent diameter of 10 μm or more of 4 or less per square centimeter.

  In the sputtering target of the present invention, the non-erosion region roughened by the blast treatment has a clean surface state. Thereby, it is possible to suppress the generation of a sudden large amount of particles due to the blast material remaining in the non-erosion region, and to form a stable thin film forming process and a high-quality sputtered thin film.

  In the present invention, the constituent material of the target main body is made of a metal element or an alloy containing it as a main component. Examples of metal elements include titanium (Ti), aluminum (Al), copper (Cu), nickel (Ni), cobalt (Co), tantalum (Ta), gold (Au), silver (Ag), chromium (Cr), Examples include, but are not limited to, niobium (Nb), platinum (Pt), molybdenum (Mo), and tungsten (W).

  On the other hand, the sputtering apparatus of the present invention includes a vacuum chamber, a substrate support installed in the vacuum chamber, and a substrate main body, which is disposed to face the substrate support, and a part of the surface of the target main body. A blast region having a surface roughness (Ra) of 1 μm or more and 4 μm or less and an equivalent circle diameter of 10 μm or more. A sputtering target having a non-erosion region having a number of materials of 4 or less per square centimeter; and a magnetic circuit for forming a magnetic field distribution on the surface of the sputtering target.

  In the sputtering apparatus of the present invention, the non-erosion region of the sputtering target has a clean surface state. Thereby, it is possible to suppress the generation of a sudden large amount of particles due to the blast material remaining in the non-erosion region, and to form a stable thin film forming process and a high-quality sputtered thin film.

  As described above, according to the present invention, it is possible to suppress the sudden generation of a large amount of particles due to the blast material remaining in the non-erosion region. This makes it possible to form a stable thin film forming process and a high-quality sputtered thin film.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following embodiment, A various deformation | transformation is possible based on the technical idea of this invention.

  FIG. 1 is a schematic configuration diagram of a magnetron type sputtering apparatus 20 according to an embodiment of the present invention. The sputtering apparatus 20 of this embodiment has a vacuum chamber 3 in which a vacuum exhaust pipe 1 and a gas pipe 2 are provided. A vacuum pump (not shown) is connected to the vacuum exhaust pipe 1. The gas pipe 2 introduces a process gas (hydrogen, oxygen, or an inert gas such as nitrogen or argon, a reactive gas, or the like) into the vacuum chamber 3. Inside the vacuum chamber 3, a sputtering cathode 4 and a support base 5 for supporting a substrate S such as a semiconductor wafer or a glass substrate are installed at a position facing the sputtering cathode 4. The vacuum chamber 3 and the support 5 are connected to the ground potential.

  The sputtering cathode 4 includes a sputtering target (hereinafter also simply referred to as “target”) 6, a backing plate 7, an insulating plate 8, a frame 9, and an earth shield 10.

  The target 6 is joined to the backing plate 7. The backing plate 7 is fixed to the frame 9 via an insulating plate 8. A circulation passage (not shown) through which a cooling medium for cooling the target 6 circulates is formed inside the backing plate 7. The backing plate 7 is connected to a predetermined high-voltage negative potential source or a high-frequency power source, and the frame 9 is connected to the ground potential via the vacuum chamber 3. Around the target 6, an earth shield 10 is installed to prevent the backing plate 7, the insulating plate 8 and the frame 9 from being sputtered. The earth shield 10 is fixed to the frame 9.

  A magnetic circuit 21 for forming a magnetic field distribution on the surface of the target 6 is installed on the surface of the backing plate 7 opposite to the target 6, that is, on the back side. The magnetic circuit 21 includes a yoke 11, a ring-shaped permanent magnet 12a disposed on the yoke 11, and a rod-shaped permanent magnet 12b disposed in the center thereof. The magnet 12 a and the magnet 12 b are arranged with the magnetic poles having different polarities directed toward the backing plate 7. As a result, lines of magnetic force M as shown in FIG. 1 are formed on the surface of the target 6. In this example, a magnetic field parallel to the target surface is formed on an intermediate region between the central portion and the peripheral portion of the target 6 facing the magnets 12a and 12b.

  In the sputtering apparatus 10 configured as described above, argon gas is introduced through the gas pipe 2 into the vacuum chamber 3 evacuated to a predetermined degree of vacuum. A high voltage or high frequency power having a predetermined negative potential is applied to the backing plate 7, whereby argon plasma is formed between the target 6 and the support 5. Argon ions collide with the surface of the target 6 at high speed, and particles (sputtered particles) containing atoms of the constituent material of the target 6 are emitted. The sputtered particles emitted from the surface of the target 6 adhere to the surface of the opposing substrate S and form a thin film.

  Further, the collision frequency of argon atoms by secondary electrons is increased by a magnetic field component parallel to the surface of the target 6. Thereby, the plasma density is improved, the sputtering efficiency of the target 6 is increased, and the film formation rate can be increased.

  Due to the distribution of the plasma density on the surface of the target 6, the plasma density is higher in these intermediate portions than in the central portion and the peripheral portion of the surface of the target 6. The region having a high plasma density has a higher sputtering efficiency of the target 6 than the region having a low plasma density. Therefore, as shown in FIG. 2, an erosion region 6a having a high sputtering efficiency and a non-erosion region 6b having a low sputtering efficiency are formed on the surface of the target 6. The non-erosion area | region 6b respond | corresponds to the center part and peripheral part of the surface of the target 6, and the erosion area | region 6a is cyclically | annularly formed in the position (shaded part of FIG. 2) corresponding to these intermediate parts.

  In this magnetron sputtering method, sputtered particles from the erosion region 6a are deposited on the substrate S, whereby a thin film is formed. On the other hand, some of the sputtered particles are deposited also in the non-erosion region 6b on the target surface. In this case, the deposit on the non-erosion region 6b increases in thickness with the progress of sputtering, and is peeled off from the target surface by its own internal stress. If the deposit peeled off from the target surface is mixed as a foreign substance (particle) in the thin film formed on the substrate S, a serious quality defect may be caused.

  In order to prevent this problem, a method is effective in which the non-erosion region of the target 6 is roughened by blasting to suppress the separation of sputtered particle deposits. However, although the frequency of particle generation can be reduced by blasting the non-erosion region, it is not possible to suppress sudden particle generation. This is based on the knowledge of the present inventors that there is a cause in the separation of the deposit attached on the blast material remaining in the non-erosion region.

  Therefore, in the present embodiment, the blast material remaining on the target surface is eliminated as much as possible to avoid the sudden generation of particles and realize high-quality thin film formation. Hereinafter, a method for manufacturing a target according to an embodiment of the present invention will be described.

  FIG. 3 is a process flow diagram illustrating a method for manufacturing a target. The target manufacturing method of this embodiment includes a step of preparing a target body, a step of blasting a non-erosion region on the surface of the target body (ST1), and a step of ultrasonically cleaning the non-erosion region subjected to blasting (ST2). And a step of etching the ultrasonically cleaned non-erosion region (ST3) and a step of ultrasonically cleaning the non-erosion region again (ST4).

[Preparation process of target body]
First, a target body having a predetermined size and thickness is prepared. The shape of the target body may be any geometric shape such as a circle, an ellipse, a long hole, a square, or a rectangle. The target body is composed of a molded body or sintered body of a metal element or an alloy containing the metal element as a main component. Examples of metal elements include titanium (Ti), aluminum (Al), copper (Cu), nickel (Ni), cobalt (Co), tantalum (Ta), gold (Au), silver (Ag), chromium (Cr), Examples include, but are not limited to, niobium (Nb), platinum (Pt), molybdenum (Mo), and tungsten (W).

[Blasting process (ST1)]
In this step, a region corresponding to a non-erosion region of the target body (hereinafter simply referred to as “non-erosion region”) is roughened by blasting. In this embodiment, a region corresponding to the erosion region of the target body (hereinafter simply referred to as “erosion region”) is masked in advance by a resist material such as a photoresist or other mask material, so that the non-erosion region is selectively selected. Blasted. Hereinafter, the blasted non-erosion area is also referred to as a “blasting area”. The blasting region is not limited to the surface of the target 6 but also includes the side peripheral surface.

  The surface roughness (arithmetic average surface roughness: Ra) of the surface to be processed obtained as a result of the blasting process is, for example, 1 μm or more and 4 μm or less. This is because when Ra is less than 1 μm, there is almost no effect by the blast treatment, and when Ra exceeds 4 μm, the difference in height of the target surface becomes too large and the deposit adhesion decreases. The surface roughness is adjusted by the particle size of the blast material, the irradiation pressure, the treatment time, and the like. The blast material is selected from SiC, glass beads, alumina and the like depending on the material and application of the target.

  Due to the blasting process, a part of the irradiated blasting material remains by adhering or sticking to the blasting region. Although some blasting materials can be removed by blowing air onto the blasting region after blasting, the blasting material with high adhesion strength remains as it is.

  Ultrasonic cleaning is a method for removing the blasting material remaining in the blasting region. However, it has been found by experiments of the present inventors that this ultrasonic cleaning alone has a low effect of removing the blast material remaining in the blasting region. That is, ultrasonic cleaning with a frequency of 30 to 50 kHz has a high effect of removing the blasting material adhering to or adhering to the surface of the blasting region, but it can remove the blasting material stuck inside the surface of the blasting region. It was confirmed that the residue remained. Then, the film deposited on the remaining blasting material peels off more easily than the film deposited directly on the surface of the blasted target body, and it is found that this causes sudden particle generation. It was.

  Therefore, in the present embodiment, the blasting region is cleaned as follows to obtain a sputtering target with a small number of remaining blast materials and a high cleanliness.

[Ultrasonic cleaning process (ST2)]
In this step, the blasting region of the target body is ultrasonically cleaned. In this step, the blasting region is cleaned with a jet of cleaning liquid to which ultrasonic waves are applied. The frequency of the ultrasonic wave is set to a range of 18 kHz or more and 19 kHz or less where the cleaning effect due to the occurrence of cavitation is high.

  FIG. 4 shows a schematic configuration of a cleaning apparatus used in the ultrasonic cleaning process of the target body. In this example, the target main body 60 is immersed in the cleaning liquid 14 in the cleaning tank 13, the cleaning tank 13 is vibrated by the ultrasonic oscillator 17, and the cleaning liquid 14 is circulated through the pipe 16 by driving the pump 15. Then, the blasting region of the target main body 60 is cleaned with a jet of the cleaning liquid 14 that is pumped into the cleaning tank 13.

  In this step, the residual blast material adhering to or adhering to the blasting region of the target body 60 is removed by the jet of the cleaning liquid 14 and the cavitation shock wave generated in the low-frequency ultrasonic cleaning, and the blasting region is pierced. A physical impact can be applied to the residual blast material.

[Etching process (ST3)]
Next, the ultrasonically cleaned blasting region is etched. For the etching, a wet etching method is used. The etching solution is appropriately selected depending on the blast material, the constituent material of the target body, and the like, and an appropriate acid or alkaline aqueous solution is used. As a treatment method, a method such as a dipping method or a coating method can be applied. In this embodiment, the target body is immersed in a hydrofluoric acid aqueous solution to etch the blasting region. The processing time is not particularly limited, but is set to such an extent that a large change does not occur in the predetermined surface roughness of the blast processing region. After etching, the target body is washed by washing with water or hot water.

  This step melts a small amount of the boundary portion between the blast material pierced on the surface of the target body and the target body, and weakens the physical insertion of the blast material into the target body. Thereby, the residual blast material which could not be removed in the previous ultrasonic cleaning process can be removed, or the adhesion of the blast material to the target body can be weakened.

Further, the same effect can be obtained by spraying high-pressure water on the blasting region. Therefore, instead of the etching process, a jet cleaning process using a high-pressure cleaning liquid may be employed. In this case, specifically, high-pressure water having 200 to 300 kgf / cm ² and a water amount of 20 to 30 L / min is used.

[Ultrasonic cleaning process (ST4)]
Finally, the blasting area is again ultrasonically cleaned. In this step, the same processing conditions as those in the first ultrasonic cleaning step (ST2) described above can be employed. That is, using the cleaning apparatus shown in FIG. 4, the blast treatment region is cleaned with a jet of cleaning liquid to which ultrasonic waves having a frequency of 18 kHz or more and 19 kHz or less are applied at a pressure of 200 to 300 kPa.

  By this step, the residual blast material in which the physical fitting input to the target main body surface is relaxed by the previous etching treatment step (or jet cleaning step using high-pressure cleaning water) is efficiently removed. As a result, almost all of the blast material remaining in the blasting region can be removed.

  This ultrasonic cleaning process may be performed with the mask material covering the surface of the target body removed, or may be performed without removing the mask material. When this ultrasonic cleaning process is performed with the mask material removed, the mask material is removed after the etching process (ST3).

  As described above, according to the present embodiment, after the blast treatment, the surface of the target main body is subjected to a multi-step cleaning process including a combination of the first ultrasonic cleaning, etching (or jet cleaning), and the second ultrasonic cleaning. The blast material remaining in the blasting region can be efficiently removed.

  As described above, the target main body 60 and a part of the surface of the target main body 60 are configured, and the erosion region 6a that is eroded by sputtering and the other part of the surface of the target main body 60 are configured, and the surface roughness A sputtering target 6 having a non-erosion region in which (Ra) is 1 μm or more and 4 μm or less and the number of blast materials having an equivalent circle diameter of 10 μm or more is 4 or less per square centimeter is manufactured.

  Since the surface roughness of the non-erosion region 6b is formed in the range of 1 μm or more and 4 μm or less, the target 6 of the present embodiment can improve adhesion with the sputtered material and suppress the separation of the sputtered material. . In addition, since the number of blasting materials having a circle equivalent diameter of 10 μm or more can be suppressed to 4 or less per square centimeter, the frequency of sudden generation of a large number of particles due to the separation of the sputtered material adhering to the residual blasting material Can be greatly reduced. This makes it possible to form a stable thin film forming process and a high-quality sputtered thin film.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples.

Example 1
A circular target body made of titanium (purity 5N) having a diameter of 250 mm and a thickness of 6 mm was prepared. And the area | region below 30 mm in diameter of the center part of a target main body, the area | region within 5 mm from the peripheral part of a target main body, and the side peripheral part of the target main body were blasted. Areas other than these areas were masked so as not to be affected by the blasting process.

The blasting conditions are as follows.
・ Blasting material: SiC particles with a particle size of 100 to 300 μm ・ Distance between target body and nozzle: 150 mm
・ Air pressure: 4.5kg / cm ²

  After the blast treatment, air was blown to remove the blast material on the surface of the target body (including the side peripheral surface), and then the target body was ultrasonically cleaned. In this step, pure water cleaning liquid was circulated by a pump (250 kPa) to form a jet, and at the same time, ultrasonic cleaning at 19 kHz was performed for 5 minutes. Next, the ultrasonically cleaned target body was immersed in a 3% hydrofluoric acid 10% nitric acid aqueous solution for 3 minutes, and then washed with water and hot water to remove the acid adhering to the target body. Subsequently, the masking was removed, and the pure water cleaning solution was circulated with a pump (250 kPa) to form a jet. At the same time, ultrasonic cleaning at 19 kHz was performed for 5 minutes, and then the target body was pulled up from the cleaning tank and dried.

  Next, the sputtering target manufactured through the above multistage cleaning treatment was evaluated by the following procedure.

First, the surface roughness of the target blasting region was measured with a measuring machine. As a result, the surface roughness was Ra = 2.5 μm. Next, the blasting region of the target was observed with a metal microscope, and the number of residual blasting materials was counted. As a result, the number of equivalent circle diameters was 10 μm or more, and the average was 1 per 1 cm ² . Further, the target was bonded to a backing plate to form a sputter cathode. Then, the sputtering cathode was incorporated into a magnetron sputtering apparatus, a sputtering test was performed, and the generation state of particles in the film was observed. The evaluation results are shown in FIG.

The sputtering conditions are as follows.
・ Gas and pressure: Ar gas, 0.5 Pa
・ Electric power: 7kW
・ Film thickness: 500mm (Angstrom)

  The sputtered film was formed on a 5-inch Si wafer. Particles having a size of 0.2 μm or more in the film were counted. The number of particles was the average value of the count values of 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100 batches. As a result of the measurement, the average number of particles on the 5-inch wafer was two. Moreover, the number of occurrences of sudden particles counting the number more than twice the average value was zero.

(Example 2)
A sputtering target was manufactured under the same cleaning conditions as in Example 1 except that the air pressure of the blast material was 4.1 kg / cm ² . Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 1.2 μm, the average number of residual blast materials was 1 per 1 cm ² , the average number of particles was 2, and the number of sudden particles generated was 1.

(Example 3)
A sputtering target was produced under the same cleaning conditions as in Example 1 except that the particle size of the blast material was 200 to 400 μm, the air pressure was 4.9 kg / cm ² , and the etching time was 2 minutes. Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 3.8 μm, the average number of residual blast materials was ² per 1 cm ² , the average number of particles was 2, and the number of sudden particles generated was 1.

Example 4
A sputtering target was produced under the same cleaning conditions as in Example 1 except that the particle size of the blast material was 200 to 400 μm, the air pressure was 4.7 kg / cm ² , and the etching time was 2 minutes. Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 3.5 μm, the average number of residual blast materials was 3 per 1 cm ² , the average number of particles was 1, and the number of sudden particles was 0.

(Example 5)
A sputtering target was manufactured under the same cleaning conditions as in Example 1 except that the material of the target body was aluminum and the air pressure of the blast material was 4.6 kg / cm ² . Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 2.8 μm, the average number of residual blast materials was 1 per 1 cm ² , the average number of particles was 2, and the number of sudden particles generated was 0.

(Example 6)
After the blast treatment, a sputtering target was produced under the same washing conditions as in Example 1 except that high pressure water washing was performed at a discharge pressure of 200 kgf / cm ² and a water amount of 20 L / min instead of the etching treatment. Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 2.1 μm, the average number of residual blast materials was 3 per 1 cm ² , the average number of particles was 3, and the number of sudden particles generated was 0.

(Example 7)
A sputtering target was manufactured under the same cleaning conditions as in Example 6 except that the particle size of the blast material was 200 to 400 μm, the air pressure was 4.7 kg / cm ² , and the discharge pressure of the high-pressure water cleaning liquid was 250 kgf / cm ² . . Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 3.5 μm, the average number of residual blast materials was 4 per 1 cm ² , the average number of particles was 2, and the number of sudden particles generated was 0.

(Example 8)
A sputtering target was manufactured under the same cleaning conditions as in Example 1 except that the target body was made of copper, the air pressure of the blasting material was 4.3 kg / cm ² , and the etching time was 2 minutes. Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 2.0 μm, the average number of residual blast materials was ² per 1 cm ² , the average number of particles was 2, and the number of sudden particles generated was 0.

Example 9
A sputtering target was manufactured under the same cleaning treatment conditions as in Example 1 except that the target body was made of nickel, the particle size of the blast material was 200 to 400 μm, and the air pressure was 4.3 kg / cm ² . Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 3.0 μm, the average number of residual blast materials was ² per 1 cm ² , the average number of particles was 2, and the number of sudden particles generated was 0.

(Example 10)
A sputtering target was produced under the same cleaning conditions as in Example 1 except that the target body was made of cobalt, the blasting material was set to 4.3 kg / cm ² , and the etching time was 2 minutes. Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 2.3 μm, the average number of residual blast materials was 1 per 1 cm ² , the average number of particles was 2, and the number of sudden particles generated was 1.

(Example 11)
A sputtering target was manufactured under the same cleaning conditions as in Example 1 except that the material of the target body was tantalum and the air pressure of the blast material was 4.3 kg / cm ² . Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 2.5 μm, the average number of residual blast materials was 3 per 1 cm ² , the average number of particles was 2, and the number of sudden particles generated was 0.

(Example 12)
The target body is made of gold, the air pressure of the blasting material is 4.3 kg / cm ² , and after the blasting treatment, high pressure water cleaning is performed at a discharge pressure of 200 kgf / cm ² and a water amount of 20 L / min instead of the etching treatment. A sputtering target was manufactured under the same cleaning conditions as in Example 1. Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 2.5 μm, the average number of residual blast materials was ² per 1 cm ² , the average number of particles was 2, and the number of sudden particles generated was 0.

(Example 13)
The target body was made of silver and blasted, and then the sputtering target was cleaned under the same cleaning conditions as in Example 1 except that high pressure water cleaning was performed at a discharge pressure of 200 kgf / cm ² and a water amount of 20 L / min instead of etching. Manufactured. Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 3.0 μm, the average number of residual blast materials was ² per 1 cm ² , the average number of particles was 3, and the number of sudden particles was 0.

(Example 14)
The target body is made of chromium, the air pressure of the blasting material is 4.3 kg / cm ² , and after the blasting treatment, instead of the etching treatment, high pressure water cleaning is performed at a discharge pressure of 200 kgf / cm ² and a water amount of 20 L / min. A sputtering target was manufactured under the same cleaning conditions as in Example 1. Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 2.8 μm, the average number of residual blast materials was 1 per 1 cm ² , the average number of particles was 2, and the number of sudden particles generated was 1.

(Example 15)
The target body was made of niobium, the air pressure of the blasting material was 4.3 kg / cm ² , and after the blasting treatment, instead of the etching treatment, high pressure water cleaning was performed at a discharge pressure of 200 kgf / cm ² and a water amount of 20 L / min. A sputtering target was manufactured under the same cleaning conditions as in Example 1. Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 2.5 μm, the average number of residual blast materials was 1 per 1 cm ² , the average number of particles was 1, and the number of sudden particles was 0.

(Example 16)
The target body was made of platinum, the air pressure of the blasting material was 4.3 kg / cm ² , and after the blasting treatment, instead of the etching treatment, the discharge pressure was 200 kgf / cm ² and the amount of water was 20 L / min. A sputtering target was manufactured under the same cleaning conditions as in Example 1. Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 2.5 μm, the average number of residual blast materials was 3 per 1 cm ² , the average number of particles was 1, and the number of sudden particles was 0.

(Example 17)
A sputtering target was manufactured under the same cleaning treatment conditions as in Example 1 except that the material of the target body was molybdenum and the air pressure of the blast material was 4.3 kg / cm ² . Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 2.3 μm, the average number of residual blast materials was ² per 1 cm ² , the average number of particles was 1, and the number of sudden particles was 0.

(Example 18)
A sputtering target was manufactured under the same cleaning conditions as in Example 1 except that the target body was made of tungsten, the particle size of the blast material was 200 to 400 μm, and the air pressure was 4.3 kg / cm ² . Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 2.7 μm, the average number of residual blast materials was ² per 1 cm ² , the average number of particles was 1, and the number of sudden particles was 0.

(Comparative Example 1)
A sputtering target was produced under the same cleaning treatment conditions as in Example 1 except that the particle size of the blast material was 300 to 500 μm and the air pressure was 5.3 kg / cm ² . Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 4.8 μm, the average number of residual blast materials was ² per 1 cm ² , the average number of particles was 10, and the number of occurrences of sudden particles was 4.

(Comparative Example 2)
A sputtering target was produced under the same cleaning treatment conditions as in Example 1 except that the particle size of the blast material was 300 to 500 μm and the air pressure was 4.6 kg / cm ² . Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 4.5 μm, the average number of residual blast materials was 1 per 1 cm ² , the average number of particles was 12, and the number of sudden particles was 4 times.

(Comparative Example 3)
A sputtering target was produced under the same cleaning treatment conditions as in Example 1 except that the air pressure of the blast material was 4.1 kg / cm ² and the etching time was 1 minute. Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 1.2 μm, the average number of residual blast materials was 8 per cm ² , the average number of particles was 12, and the number of sudden particles generated was 3.

(Comparative Example 4)
A sputtering target was produced under the same cleaning conditions as in Example 1 except that the particle size of the blast material was 200 to 400 μm, and after the blasting treatment, only the ultrasonic cleaning was performed without performing the etching treatment. Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 3.5 μm, the average number of residual blast materials was 15 per 1 cm ² , the average number of particles was 15, and the number of sudden particles generated was 4.

(Comparative Example 5)
Only the ultrasonic cleaning was performed after producing the titanium target body without blasting. The ultrasonic cleaning treatment conditions were the same as those in Example 1. The evaluation results are shown in FIG. The surface roughness was Ra = 0.5 μm, the average number of residual blast materials was 0 per cm ² , the average number of particles was 13, and the number of sudden particles generated was 4.

(Comparative Example 6)
Example 1 except that the particle size of the blast material is 200 to 400 μm, the air pressure is 4.6 kg / cm ² , and the applied ultrasonic frequency of ultrasonic cleaning after blasting and ultrasonic cleaning after etching is 30 kHz. A sputtering target was manufactured under the same cleaning treatment conditions. Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 3.2 μm, the average number of residual blast materials was 9 per 1 cm ² , the average number of particles was 10, and the number of occurrences of sudden particles was 4.

(Comparative Example 7)
The air pressure of the blast material is 4.4 kg / cm ² , the applied ultrasonic frequency of ultrasonic cleaning after blasting is 30 kHz, and instead of etching, high pressure water cleaning is performed at a discharge pressure of 250 kgf / cm ² and a water volume of 20 L / min. A sputtering target was manufactured under the same cleaning conditions as in Example 1 except that the applied ultrasonic frequency of ultrasonic cleaning after high-pressure water cleaning was 30 kHz. Thereafter, the same evaluation as in Example 1 was performed. The evaluation results are shown in FIG. The surface roughness was Ra = 2.1 μm, the average number of residual blast materials was 9 per 1 cm ² , the average number of particles was 10, and the number of occurrences of sudden particles was 3.

It is a schematic block diagram of the sputtering device by embodiment of this invention. 1 is a perspective view schematically showing a sputtering target according to an embodiment of the present invention. It is a process flow figure explaining a manufacturing method or a cleaning method of a sputtering target by an embodiment of the present invention. It is a schematic block diagram of the ultrasonic cleaning apparatus of the target main body in embodiment of this invention. It is a graph which shows the experimental result of the Example of this invention. It is a graph which shows the experimental result of the comparative example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vacuum exhaust piping 2 ... Gas piping 3 ... Vacuum tank 4 ... Sputtering cathode 5 ... Support stand 6 ... Target (sputtering target)
6a ... Erosion region 6b ... Non-erosion region 7 ... Backing plate 8 ... Insulating plate 9 ... Frame 10 ... Earth shield 11 ... Yoke 12a, 12b ... Magnet 13. .... Cleaning tank 14 ... Cleaning liquid 15 ... Pump 16 ... Piping 17 ... Ultrasonic oscillator 20 ... Sputtering device 60 ... Target body S ... Substrate

Claims (7)

A method of manufacturing a sputtering target for a magnetron sputtering apparatus,
Prepare the target body,
Blasting the non-erosion region of the target body surface;
Ultrasonically cleaning the non-erosion region;
Etch the non-erosion region ultrasonically cleaned, or jet cleaning with a cleaning liquid,
A method for manufacturing a sputtering target, wherein the non-erosion region is subjected to ultrasonic cleaning again. It is a manufacturing method of the sputtering target according to claim 1,
The said blasting process roughens the said non-erosion area | region to surface roughness (Ra) 1 micrometer or more and 4 micrometers or less. The manufacturing method of a sputtering target. It is a manufacturing method of the sputtering target according to claim 2,
The step of ultrasonically cleaning the non-erosion region is a method of manufacturing a sputtering target in which the non-erosion region is cleaned with a jet of cleaning liquid to which an ultrasonic wave having a frequency of 18 kHz to 19 kHz is applied. It is a manufacturing method of the sputtering target according to claim 3,
The manufacturing method of the sputtering target which makes the pressure of the said jet flow 200 kPa or more and 300 kPa or less. A method for cleaning a sputtering target in which at least a part of a surface is subjected to blasting,
Ultrasonically cleaning the blasting region of the sputtering target;
Etching the ultrasonically cleaned blasting region, or jet cleaning with a cleaning liquid,
A method for cleaning a sputtering target, wherein the blasting region is again subjected to ultrasonic cleaning. A method for cleaning a sputtering target according to claim 5,
The step of ultrasonically cleaning the blasting region includes cleaning the blasting region with a jet of cleaning liquid to which an ultrasonic wave of 18 kHz or more and 19 kHz or less is applied. A method for cleaning a sputtering target according to claim 6,
A method for cleaning a sputtering target, wherein the pressure of the jet flow is 200 kPa or more and 300 kPa or less.

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