JP4965480B2 - Manufacturing method of backing plate and cleaning method of backing plate - Google Patents

Description

  The present invention relates to a method for manufacturing a backing plate for holding a sputtering target, a backing plate, a sputter cathode including the backing plate, a sputtering apparatus including the sputter cathode, and a cleaning method for the backing plate.

  Conventionally, a sputtering method has been used as a film forming technique for forming a thin film on a substrate. In this sputtering method, a rare gas such as Ar introduced into the vacuum chamber is ionized, and when the ionized Ar collides with the sputtering target, sputtered particles are ejected from the target to form a thin film on the substrate. Is done.

  In a magnetron sputtering method using a magnetic field, which is a kind of sputtering method, secondary electrons struck out from the target surface spirally move by a magnetic field applied to the target surface. The collision of the secondary electrons that spirally collide with Ar increases the collision frequency for ionization of Ar, so that the deposition rate is increased.

  In such film formation by sputtering, the sputtered particles struck from the target cause a deposited film to be formed on the part where the sputtering efficiency of the target is low (non-erosion region), the backing plate that holds the target, or each part in the vacuum chamber. In some cases, this deposited film adversely affects the formation of a thin film on the substrate. For example, when a part of the deposited film is peeled off and particles (unnecessary particles) are generated in the vacuum chamber, and the particles are mixed as a foreign substance into the thin film on the substrate, so that the quality of the thin film is deteriorated. There is.

  As a technique related to such a problem, for example, Patent Document 1 discloses a technique of roughening the surface of a target or the surface of a backing plate by blasting. It is described that the blasted portion traps coarse particles (sputtered particles) and prevents the coarse particles from being scattered on the substrate.

Patent Document 2 describes a backing plate whose surface is partially blasted. This blast treatment improves the adhesion of the film adhering to the backing plate and prevents particles (unnecessary particles) from being mixed between the shield and the target. It is described.
Japanese Patent Laid-Open No. 4-301074 (paragraph [0009]) Japanese Patent Laid-Open No. 10-30174 (paragraphs [0020], [0023], FIG. 3)

  However, when the surface of the backing plate is blasted by the method described in Patent Document 1 or Patent Document 2, for some reason, sudden particles are generated from the backing plate. In other words, when the blasting process is performed on the backing plate in order to reduce the particles, there is a problem that many particles whose cause is unknown are generated from the backing plate.

  When sudden particles are generated in this way, the particles are mixed as a foreign substance into the thin film on the substrate, so that the yield is remarkably lowered and the production is hindered. In particular, as the wiring pattern of the thin film on the substrate is miniaturized, even a small amount of particles mixed into the thin film may become a serious problem.

  In order to investigate the cause of the sudden particles generated on the backing plate, the present inventors have observed unevenness (specific surface area) on the surface of the backing plate, the surface state, and the like. As a result, the inventors have found that the residual blasting material remaining in the blasted blasting part has a blasting material stuck in the blasting part in addition to the blasting material adhered and fixed to the blasting part. discovered. The blasting material pierced in the blasting unit cannot be removed from the blasting unit by simple cleaning. It is considered that the film deposited on the blasting material that has pierced the blasting part easily peels off, and this causes sudden particles.

  In view of the circumstances as described above, an object of the present invention is a manufacturing method of a backing plate that reduces the generation of particles and improves the quality and manufacturing efficiency of a thin film formed on a substrate, and is manufactured by this manufacturing method. Another object is to provide a backing plate and a technique related thereto.

  In order to achieve the above object, a manufacturing method of a backing plate according to the present invention is a manufacturing method of a backing plate for holding a sputtering target, wherein a backing plate body is prepared, and the sputtering target of the backing plate body is formed. Forming at least a part other than the formation region which is a region to be formed, forming a blasting unit, ultrasonically cleaning the blasting unit, etching the ultrasonically cleaned blasting unit, or cleaning liquid Then, the blasting unit is ultrasonically cleaned again.

  As described above, in the present invention, the backing plate is manufactured by cleaning the blast processing unit in three stages. By this three-stage cleaning, the blasting material that has pierced the blasting unit can be removed appropriately, and the generation of sudden particles can be reduced. Thereby, improvement of the quality and manufacturing efficiency of the thin film formed on a board | substrate is realizable.

  In the manufacturing method of the backing plate, in the step of forming the blast processing portion, the blast processing portion may be roughened to have a surface roughness (Ra) of 1 μm to 4 μm.

  Thereby, since the adhesiveness of the film | membrane deposited on a blast process part can be improved, the particle which generate | occur | produces suddenly can further be reduced.

  In the manufacturing method of the backing plate, the ultrasonic cleaning step may ultrasonically clean the blast processing unit with a jet of cleaning liquid to which an ultrasonic wave of 18 kHz to 19 kHz is applied.

  Thereby, the blast material pierced by the blast processing part can be further appropriately removed.

  In the manufacturing method of the backing plate, the pressure of the jet may be 200 kPa or more and 300 kPa or less.

  Thereby, the blast material pierced by the blast processing part can be further appropriately removed.

The backing plate according to the present invention is a backing plate for holding a sputtering target, and at least a part of the backing plate body other than a forming region in which the sputtering target of the backing plate body is formed is blasted. And a blast treatment part having a surface roughness (Ra) of 1 μm or more and 4 μm or less and 4 or less of the blast material having a circle equivalent diameter of 10 μm or more per 1 cm ² .

In the backing plate according to the present invention, when the surface roughness of the blasting part is 1 μm or more and 4 μm or less, the adhesion of the film deposited on the blasting part can be improved. Further, among the blast materials remaining in the blast processing section, the number of blast materials having a circle-equivalent diameter of 10 μm or more is set to 4 or less per 1 cm ² , whereby suddenly generated particles can be reduced. Thereby, improvement of the quality and manufacturing efficiency of the thin film formed on a board | substrate is realizable.

  In the backing plate, the backing plate body may be made of aluminum, copper, titanium, stainless steel, or an alloy mainly composed of any of these materials.

In the sputtering cathode according to the present invention, a sputtering target, a backing plate body holding the sputtering target, and at least a part of the backing plate body other than a formation region where the sputtering target is formed are blasted. And a blast treatment part having a surface roughness (Ra) of 1 μm or more and 4 μm or less and 4 or less of the blast material having a circle equivalent diameter of 10 μm or more per 1 cm ² .

The sputtering apparatus according to the present invention includes a vacuum chamber, a sputtering target, a backing plate body that holds the sputtering target, and at least a part of the backing plate body other than a formation region that is a region where the sputtering target is formed. A blasting portion formed by blasting, having a surface roughness (Ra) of 1 μm or more and 4 μm or less, and 4 or less of the blasting material having an equivalent circle diameter of 10 μm or more per 1 cm ^2. And a sputter cathode for scattering sputtered particles in the vacuum chamber when a voltage is applied.

  In the present specification, the “sputter cathode” includes a bonded body formed by bonding a sputtering target and a backing plate, and an integrally formed body formed integrally with the backing plate and the backing plate.

  The method for cleaning a backing plate according to the present invention includes ultrasonically cleaning a blasting unit formed by blasting a backing plate, etching the ultrasonically cleaned blasting unit, or jetting with a cleaning liquid. Wash and ultrasonically clean the blasting unit again.

  In the backing plate cleaning method, the ultrasonic cleaning step may ultrasonically clean the blasting unit with a jet of cleaning liquid to which an ultrasonic wave of 18 kHz or more and 19 kHz or less is applied.

  In the backing plate cleaning method, the jet pressure may be 200 kPa or more and 300 kPa or less.

  As described above, according to the present invention, a method for manufacturing a backing plate that reduces the generation of particles and improves the quality and manufacturing efficiency of a thin film formed on a substrate, and the backing plate manufactured by this manufacturing method. , And techniques related thereto.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram showing a sputtering apparatus according to an embodiment of the present invention. FIG. 2 is an enlarged view of the vicinity of the sputtering cathode and shield of the sputtering apparatus. In this embodiment, a magnetron type sputtering apparatus will be described as an example of a sputtering apparatus.

  As shown in FIG. 1, the sputtering apparatus 100 includes a grounded vacuum chamber 20, a sputter cathode 10 disposed inside the vacuum chamber 20, and a magnetic field forming unit for forming a magnetic field distribution in the vicinity of the sputter cathode 10. 30.

  A vacuum exhaust pipe 23 connected to the vacuum pump 28 and a gas introduction pipe 24 for introducing a gas such as Ar into the vacuum tank 20 are connected to the vacuum tank 20. A stage 22 that supports the substrate 27 to be processed and functions as an anode is disposed inside the vacuum chamber 20. In addition, the sputter cathode 10 is provided in the vacuum chamber 20 so as to face the stage 22 with an insulating material 25 interposed therebetween.

  The sputtering cathode 10 includes a sputtering target 2 (hereinafter referred to as a target) and a backing plate 1 for holding the target 2. The backing plate 1 is applied to a high voltage minus. A shield 26 is provided around the sputter cathode 10 to prevent parts other than the target from being sputtered. The shield 26 may be grounded. The sputter cathode 10 has a slight gap 8 between the shield 26 (see FIG. 2).

  A magnetic field forming unit 30 is arranged in the surface (back surface) direction opposite to the surface (front surface) on which the target 2 of the backing plate 1 is provided. The magnetic field forming unit 30 is an annular first magnet 32a, is located in the center of the first magnet 32a, has a cylindrical second magnet 32b, and a magnet support unit that supports the magnets 32a and 32b. 31. The first magnet 32a and the second magnet 32b may be permanent magnets or electromagnets. The magnetic poles on the backing plate side of the first and second magnets 32a and 32b are made different from each other. Thereby, lines of magnetic force are formed between the first magnet and the second magnet, and a magnetic field distribution as shown in FIG. 1 is formed in the vicinity of the surface of the target 2.

  FIG. 3 is an exploded perspective view of the sputter cathode 10. As shown in FIG. 3, the backing plate 1 is disk-shaped and has a front surface 1 a having a formation region 3 that is a region where the target 2 is formed, a side peripheral surface 1 b, and a back surface 1 c. Similarly, the target 2 has a disk shape, and has, for example, a front surface 2a sputtered by Ar, a side peripheral surface 2b, and a back surface 2c joined to the backing plate 1. The formation region 3 of the backing plate 1 and the back surface 2c of the target 2 are bonded together by bonding using, for example, an appropriate brazing material. The shape of the target 2 and the backing plate 1 is not limited to a disc shape, and may be a flat plate shape with a rectangular surface or other shapes.

  In FIG. 3, the backing plate 1 and the target 2 are joined to form the sputter cathode 10. However, in the sputter cathode 10, the backing plate 1 and the target 2 may be integrally formed of the same material. Also in this case, the target 2 is formed on the formation region 3 of the surface 1 a of the backing plate 1. In this specification, the sputter cathode 10 is described as including a bonded body formed by bonding the backing plate 1 and the target 2 and an integrally formed body formed by integrally forming the backing plate 1 and the target 2. To do.

  The backing plate 1 is formed of, for example, Ti, Al, Cu, stainless steel, or an alloy mainly composed of any of these materials. The target 2 is formed of, for example, Ti, Al, Cu, Ni, Co, Ta, Au, Ag, Cr, Nb, Pt, Mo, and W.

  A region 4 other than the formation region 3 of the surface 1a of the backing plate (backing plate main body) 1 and the side peripheral surface 1b are blasted with a blast material, and a blast processing unit 5 is formed. In the present embodiment, as described above, the sputter cathode 10 has a slight gap 8 between the shield 26 (see FIG. 2). At the time of sputtering, sputtered particles struck out from the target 2 enter the gap 8 and a deposited film is formed. Therefore, typically, the region 4 other than the formation region 3 of the surface 1a and the entire side peripheral surface 1b, which are portions where the backing plate 1 is in contact with the gap 8, become the blast processing unit 5. However, when there is a possibility that a deposited film is formed on the back surface 1c of the backing plate, for example, when the back surface 1c of the backing plate 1 is in contact with the gap 8, the back surface 1c may be blasted.

  The blasting unit 5 may be formed by blasting a part of the region 4 of the surface 1a of the backing plate, or may be formed by blasting a part of the side peripheral surface 1b. Alternatively, the side circumferential surface 1b may not be blasted and may be formed by blasting all or part of the region 4, and the region 4 may not be blasted and all or part of the side circumferential surface 1b may be formed. It may be formed by blasting. That is, any portion of the front surface 1a, the side peripheral surface 1b, and the back surface 1c of the backing plate 1 as long as it is a portion other than the formation region 3 may be blasted. Of course, the non-erosion region of the target 2 may be blasted in the same manner.

The blast treatment unit 5 has a surface roughness (Ra) of 1 μm or more and 4 μm or less, and 4 or less blast materials having a circle equivalent diameter of 10 μm or more per 1 cm ² . The range of the surface roughness and the number of blast materials having an equivalent circle diameter of 10 μm or more are values derived by preparing samples having various values and performing actual sputtering (see FIG. 6 described later). ).

As described above, the surface roughness of the blasting unit 5 of the backing plate 1 is 1 μm or more and 4 μm or less, so that the film formed by depositing the sputtered particles struck from the target 2 on the blasting unit 5. Therefore, the generation of particles can be reduced. Further, among the blasting materials remaining in the blasting unit 5 of the backing plate 1, the number of blasting materials having a circle-equivalent diameter of 10 μm or more is 4 or less per 1 cm ^2, so that the residual blasting material stuck into the blasting unit 5 Particles (sudden particles) generated when the film deposited thereon easily peels off can be reduced. Thereby, the quality of the thin film formed on the to-be-processed substrate 27 and the improvement of manufacturing efficiency are realizable.

  Next, an embodiment of a method for manufacturing the backing plate 1 will be described. FIG. 4 is a flowchart showing the manufacturing method of the backing plate according to the present embodiment.

  First, a disk-shaped backing plate 1 (backing plate body) is prepared (step 1). The shape of the backing plate 1 is not limited to the disk shape as described above, and the surface 1a may be a rectangular flat plate shape or other shapes. The backing plate 1 is made of, for example, Ti, Al, Cu, stainless steel, or an alloy mainly composed of any of these materials. The formation region 3 where the target 2 on the front surface 1a of the backing plate 1 is formed (bonded) and the back surface 1c are masked as a protection region. In addition, when the backing plate 1 and the target 2 are integrally formed, the back surface 1c of the backing plate 1, the surface 2a and the side peripheral surface 2b of the target 2 are masked.

  When the backing plate 1 is masked, the region 4 and the side peripheral surface 1b of the surface 1a are blasted using a blasting device to form a blasting unit 5 (step 2). The region to be blasted can be appropriately changed in consideration of the region in contact with the gap 8 among the surfaces 1a, 1b, and 1c of the backing plate (see FIG. 2).

In consideration of the material of the backing plate 1, SiC, Al ₂ O ₃ , glass beads or the like is used for the blast material. As for the particle size of the blast material, the average equivalent circle diameter is 100 μm to 500 μm. Distance between the nozzle and the blast treatment surface 5 of the blasting apparatus is, for example, a 150 mm, air pressure blasting device ^is a ^{4.0kg / cm 2 ~4.7kg / cm 2} . Thus, by appropriately setting the particle size of the blast material, the distance from the nozzle, and the air pressure, the blast treatment unit 5 having a surface roughness (Ra) of 1 μm to 4 μm can be formed. Thereby, since the adhesion of the film formed by depositing the sputtered particles on the blast processing unit 5 can be improved, the generation of particles can be reduced.

  Next, in order to remove the residual blast material remaining in the blast processing unit 5, the backing plate 1 is ultrasonically cleaned with a jet of cleaning liquid to which ultrasonic waves are applied (step 3).

  FIG. 5 is a schematic diagram illustrating an example of a cleaning device. The cleaning device 50 includes a cleaning tank 52, a pump 53 for generating a jet of cleaning liquid 55 in the cleaning tank 52, and an ultrasonic transmitter 51 for applying ultrasonic waves to the jet of cleaning liquid 55. . The cleaning tank 52 and the pump 53 are connected by a pipe 54. Although the configuration shown in FIG. 5 is given as an example of the cleaning device 50, the configuration is not limited to this, and a cleaning device 50 having the same configuration may be used.

  The backing plate 1 is held in a cleaning tank 52 and is cleaned by a jet of cleaning liquid 55 to which ultrasonic waves are applied. In this case, the pressure of the jet is 200 kPa or more and 300 kPa or less, and the ultrasonic frequency is 18 kHz or more and 19 kHz or less. The cleaning time is, for example, 5 minutes. By this cleaning, out of the residual blasting material remaining in the blasting unit 5, the blasting material adhering to or fixed to the blasting unit 5 can be removed from the blasting unit 5, and the blasting material stuck into the blasting unit 5 Can be shocked.

  Next, the blast processing part 5 of the backing plate 1 is etched (step 4). In this case, for example, the blasting unit 5 is etched by immersing the backing plate 1 in hydrofluoric acid. The etching time is, for example, 3 minutes. The concentration of hydrofluoric acid and the etching time are appropriately set according to the material of the backing plate and the blast material. By such an etching process, a very small amount of the boundary surface between the blast processing unit 5 and the blast material pierced into the blast processing unit 5 can be melted, and the degree of piercing of the blast material can be reduced. After the etching, the backing plate 1 is washed with water, and the nitric acid is washed away. Thereafter, the masking is removed.

  Next, the blasting unit 5 of the backing plate 1 is ultrasonically cleaned again using the cleaning device 50 shown in FIG. 5 (step 5). In this case as well, as in step 3 described above, the jet pressure is set to 200 kPa to 300 kPa, and the ultrasonic frequency is set to 18 kHz to 19 kHz. The cleaning time is, for example, 5 minutes. When the sputter cathode 10 is a joined body of the backing plate 1 and the target 2, the formation region 3 of the backing plate 1 and the back surface 2 c of the target are then bonded to manufacture the sputter cathode 10.

  Thus, in this embodiment, the blast processing unit 5 is cleaned in three stages (steps 3 to 5). By this three-stage cleaning, the blast material that has pierced the blast processing unit 5 can be appropriately removed. Thereby, sudden particles generated from the backing plate 1 can be reduced. Therefore, when this backing plate 1 is used and a thin film is formed on the to-be-processed substrate 27, the quality and manufacturing efficiency of this thin film can be improved.

Further, in the ultrasonic cleaning in Step 3 and Step 4, the frequency of the ultrasonic wave is set to 18 kHz or more and 19 kHz or less, and the jet pressure is set to 200 kPa or more and 300 kPa or less. That is, the blast processing unit 5 is not formed by the ultrasonic wave of 18 kHz to 19 kHz which is a low frequency band which is not generally used and the jet flow instead of the frequency band which is generally used in ultrasonic cleaning of 30 kHz to 50 kHz. Washed. Thereby, it is possible to reduce the number of blast materials having an equivalent circle diameter of 10 μm or more remaining in the blast processing unit 5 to 4 or less per 1 cm ² . Thereby, the sudden particle which generate | occur | produces from the backing plate 1 can further be reduced. In ultrasonic cleaning with a frequency of 30 kHz to 50 kHz, it is difficult to reduce the number of blast materials having a circle equivalent diameter of 10 μm or more remaining in the blast processing unit 5 to 4 or less per 1 cm ² (the sixth and seventh described later). See comparative example).

In step 4, instead of the etching process, the blasting unit 5 may be jet-cleaned (high-pressure water cleaned) with a cleaning liquid. In this case, the discharge pressure of the cleaning liquid is 200 kgf / cm ² or more and 300 kgf / cm ² or less, and the amount of water is 20 l / min or more and 30 l / min or less. This jet cleaning can also reduce the degree of piercing of the blasting material that has pierced the blasting unit 5 as in the etching process.

(First embodiment)
Next, an embodiment of the manufacturing method of the backing plate 1 will be described. In the following description, parts having the same configurations and functions as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

  FIG. 6 is a diagram for comparing the material and surface roughness of the backing plate from the first embodiment to the eighth embodiment and from the first comparative example to the seventh comparative example.

  In this embodiment, first, a backing plate 1 (backing plate body) made of Cu was prepared (step 1). The formation region 3 which is the region where the target 2 on the front surface 1a of the backing plate 1 is formed (bonded) and the back surface 1c are masked.

Next, the area | region 4 and the side peripheral surface 1b of the surface 1a are blasted using a blast processing apparatus, and the blasting process part 5 is formed (step 2). As the blast material, SiC having a diameter of 100 μm to 300 μm was used. The distance between the nozzle of the blast treatment device and the blast treatment surface 5 was 150 mm, and the air pressure of the blast treatment device was 4.3 kg / cm ² .

  When the blast processing unit 5 is formed, the backing plate 1 is ultrasonically cleaned with a jet of cleaning liquid to which ultrasonic waves are applied (step 3). The jet pressure was 200 kPa or more and 300 kPa or less, and the frequency of the ultrasonic waves was 19 kHz. The washing time was 5 minutes.

  Next, the blasting part 5 was etched by immersing the backing plate 1 in hydrofluoric acid (hydrogen fluoride 3%, nitric acid 10%) for 3 minutes (step 4). After the etching, the backing plate 1 was washed with water or hot water, and then the masking was removed.

  The backing plate 1 is ultrasonically cleaned again by a jet of cleaning liquid to which ultrasonic waves are applied (step 5). The pressure of the jet was set to 200 kPa or more and 300 kPa or less as in Step 3, and the ultrasonic frequency was set to 19 kHz. The washing time was 5 minutes. Thereafter, the backing plate 1 was dried.

The surface roughness of the blasted surface 5 of the backing plate 1 manufactured in this way and the number of residual blast materials were evaluated. As a result of measuring the surface roughness (Ra) with a roughness measuring instrument, the surface roughness (Ra) was 2.2 μm. Moreover, as a result of measuring a blast material having a circle-equivalent diameter of 10 μm or more remaining in the blast processing unit 5 with a metal microscope, the average number of residual blast materials was ² per 1 cm ² .

  The formation region 3 of the backing plate 1 and the back surface 2c of the target are bonded, and the sputter cathode 10 is manufactured. A titanium target having a diameter of 250 mm and a thickness of 6 mm made of Ti with a purity of 5N was used as the target. The sputter cathode 10 was set in the sputtering apparatus 100, and the generation state of particles was observed.

  Ar was used as the sputtering gas, and the gas pressure was 0.5 Pa. The sputtering power was 7 kW. A silicon wafer 27 having a diameter of 5 inches (125 mm) was used as the substrate 27 to be processed, and a thin film having a thickness of 50 nm was formed on the silicon wafer 27.

  The number of particles mixed in the thin film on the silicon wafer 27 is counted, and the backing plate 1 according to this embodiment is evaluated. The diameter of the counted particles was 0.2 μm or more, and the particles were counted in 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100 batches. As a result, the average number of particles mixed in the thin film on the silicon wafer 27 was one.

  Furthermore, when a silicon wafer 27 containing more than twice the average number of particles (one in the case of this embodiment) is found, it is estimated that sudden particles are generated from the backing plate 1, The performance of the backing plate 1 is evaluated. In the present embodiment, the number of silicon wafers 27 in which particles more than twice the average number of particles were mixed was not found and was zero. That is, in the thin film formation using the backing plate 1 according to the present embodiment, no sudden particles were generated (0 times).

(Second Embodiment)
Next, another embodiment of the manufacturing method of the backing plate 1 will be described. In the following description, differences from the first embodiment will be mainly described. Similarly, the third embodiment to the seventh comparative example, which will be described later, will be described with a focus on differences from the first embodiment.

In the present embodiment, the material of the backing plate 1 is stainless steel. Moreover, the particle diameter of the blasting material for blasting was such that the average equivalent circle diameter was 200 μm to 400 μm, and the air pressure of the blasting device was 4.6 kg / cm ² .

The surface roughness (Ra) of the blasting part 5 of the backing plate 1 manufactured under such conditions is 3.2 μm, and the blasting material having a circle equivalent diameter of 10 μm or more remaining in the blasting part 5 is 1 cm ^2. It was 1 on average.

  A thin film was formed on the silicon wafer 27 by the sputtering apparatus 100 having the backing plate 1 and the particles mixed in the thin film were measured. As a result, the average number of particles was three. Further, no silicon wafer 27 mixed with particles more than twice the average number of particles was found, and no sudden particles were generated (0 times).

(Third embodiment)
Next, still another embodiment of the manufacturing method of the backing plate 1 will be described.

In this embodiment, the material of the backing plate 1 is Ti. As for the particle diameter of the blasting material for blasting, the average equivalent circle diameter was 300 μm to 500 μm, and the air pressure of the blasting device was 4.7 kg / cm ² . Moreover, the etching time of the etching process of the blast processing part 5 was set to 2 minutes.

The surface roughness (Ra) of the blasting part 5 of the backing plate 1 manufactured under such conditions is 3.8 μm, and a blasting material having an equivalent circle diameter of 10 μm or more remaining in the blasting part 5 is 1 cm ^2. The average number was 4 per unit.

  A thin film was formed by the sputtering apparatus 100, and the particles mixed in the thin film were measured. As a result, the average number of particles was three. Moreover, the number of occurrences of sudden particles was one.

(Fourth embodiment)
Next, still another embodiment of the manufacturing method of the backing plate 1 will be described.

In the present embodiment, the backing plate 1 is made of Al, and the air pressure of the blasting apparatus is 4.0 kg / cm ² .

The surface roughness (Ra) of the blasting part 5 of the backing plate 1 manufactured under such conditions is 1.2 μm, and the blasting material having an equivalent circle diameter of 10 μm or more remaining in the blasting part 5 is 1 cm ^2. The average number was 2 per unit.

  A thin film was formed by the sputtering apparatus 100, and the particles mixed in the thin film were measured. As a result, the average number of particles was two. The number of sudden particle generations was zero.

(Fifth embodiment)
Next, still another embodiment of the manufacturing method of the backing plate 1 will be described.

  In this embodiment, the average particle diameter of the blasted blast material is 200 μm to 400 μm.

The surface roughness (Ra) of the blasting part 5 of the backing plate 1 manufactured under such conditions is 2.6 μm, and the blasting material having a circle equivalent diameter of 10 μm or more remaining in the blasting part 5 is 1 cm ^2. The average number was 2 per unit.

  A thin film was formed by the sputtering apparatus 100, and the particles mixed in the thin film were measured. As a result, the average number of particles was four. The number of sudden particle generations was zero.

(Sixth embodiment)
Next, still another embodiment of the manufacturing method of the backing plate 1 will be described.

In this embodiment, the average diameter of the equivalent circle diameter of the blasting material for blasting is 200 μm to 400 μm, and the air pressure of the blasting apparatus is 4.4 kg / cm ² .

Furthermore, in this embodiment, instead of the etching process (step 4), the blast processing unit 5 is jet-cleaned (high-pressure water cleaned) with a cleaning liquid. In this case, the discharge pressure of the cleaning liquid was 200 kgf / cm ² and the amount of water was 20 l / min.

The surface roughness (Ra) of the blasting part 5 of the backing plate 1 manufactured under such conditions is 2.9 μm, and a blasting material having a circle equivalent diameter of 10 μm or more remaining in the blasting part 5 is 1 cm ^2. It was 3 on average.

  A thin film was formed by the sputtering apparatus 100, and the particles mixed in the thin film were measured. As a result, the average number of particles was four. The number of sudden particle generations was zero.

(Seventh embodiment)
Next, still another embodiment of the manufacturing method of the backing plate 1 will be described.

In this embodiment, the average diameter of the equivalent circle diameter of the blasting blasting material is 300 μm to 500 μm, and the air pressure of the blasting apparatus is 4.5 kg / cm ² .

In the present embodiment, jet cleaning is used instead of the etching process (step 4), the discharge pressure of the cleaning liquid is 250 kgf / cm ^2, and the amount of water is 20 l / min.

The surface roughness (Ra) of the blasting part 5 of the backing plate 1 manufactured under such conditions is 3.5 μm, and the blasting material having an equivalent circle diameter of 10 μm or more remaining in the blasting part 5 is 1 cm ^2. The average number was 2 per unit.

  A thin film was formed by the sputtering apparatus 100, and the particles mixed in the thin film were measured. As a result, the average number of particles was three. The number of sudden particle generations was zero.

(Eighth embodiment)
Next, still another embodiment of the manufacturing method of the backing plate 1 will be described.

In this embodiment, the material of the backing plate 1 is an aluminum alloy. As for the particle diameter of the blasting material, the average equivalent circle diameter was 200 μm to 400 μm, and the air pressure of the blasting device was 4.4 kg / cm ² .

The surface roughness (Ra) of the blasting part 5 of the backing plate 1 manufactured under such conditions is 3.0 μm, and the blasting material having an equivalent circle diameter of 10 μm or more remaining in the blasting part 5 is 1 cm ^2. The average number was 2 per unit.

  A thin film was formed by the sputtering apparatus 100, and the particles mixed in the thin film were measured. As a result, the average number of particles was 5. The number of sudden particle generations was zero.

(First comparative example)
Next, a first comparative example in the manufacturing method of the backing plate 1 will be described.

In the first comparative example, the blasting material blasting material had an average equivalent circle diameter of 300 μm to 500 μm, and the air pressure of the blasting device was 5.3 kg / cm ² .

The surface roughness (Ra) of the blasting part 5 of the backing plate 1 manufactured under such conditions is 4.3 μm, and the blasting material having an equivalent circle diameter of 10 μm or more remaining in the blasting part 5 is 1 cm ^2. It was 3 on average.

  A thin film was formed by the sputtering apparatus 100 and the particles mixed in the thin film were measured. As a result, the average number of particles was 8. The number of sudden particle generations was three.

  It can be seen from the first comparative example that when the surface roughness of the blast processing unit 5 exceeds 4.0, the effect of reducing the generation of particles and sudden particles is reduced. As described above, when the surface roughness is larger than 4.0, the particle reduction effect is lowered. When the surface roughness is increased, the groove of the blast processing unit 5 becomes deep, and the film deposited on the blast processing unit 5 This is thought to be due to variations in the adhesion.

(Second comparative example)
Next, a second comparative example in the manufacturing method of the backing plate 1 will be described.

In this second comparative example, the air pressure of the blast treatment apparatus was 4.6 kg / cm ² . Moreover, the etching time of the etching process of the blast processing part 5 was set to 1 minute.

The surface roughness (Ra) of the blasting part 5 of the backing plate 1 manufactured under such conditions is 2.5 μm, and the blasting material having an equivalent circle diameter of 10 μm or more remaining in the blasting part 5 is 1 cm ^2. The average was 9 per unit.

  A thin film was formed by the sputtering apparatus 100 and the particles mixed in the thin film were measured. As a result, the average number of particles was 8. The number of sudden particle generations was three.

(Third comparative example)
Next, a third comparative example in the manufacturing method of the backing plate 1 will be described.

In this second comparative example, the air pressure of the blast treatment apparatus was 3.8 kg / cm ² .

The surface roughness (Ra) of the blasting part 5 of the backing plate 1 manufactured under such conditions is 0.8 μm, and the blasting material having a circle equivalent diameter of 10 μm or more remaining in the blasting part 5 is 1 cm ^2. The average number was 5 per unit.

  A thin film was formed by the sputtering apparatus 100, and the particles mixed in the thin film were measured. As a result, the average number of particles was nine. In addition, the number of sudden particle generations was four.

(Fourth comparative example)
Next, the 4th comparative example in the manufacturing method of backing plate 1 is explained.

In the fourth comparative example, the blasting blast material had an average equivalent circle diameter of 200 μm to 400 μm, and the air pressure of the blasting apparatus was 4.5 kg / cm ² .

  Furthermore, in the fourth comparative example, the etching process after ultrasonic cleaning (step 4) and the ultrasonic cleaning process after this etching process (step 5) are not performed.

The surface roughness (Ra) of the blasting part 5 of the backing plate 1 manufactured under such conditions is 2.8 μm, and the blasting material having a circle equivalent diameter of 10 μm or more remaining in the blasting part 5 is 1 cm ^2. The average number per unit was 15.

  A thin film was formed by the sputtering apparatus 100, and the particles mixed in the thin film were measured. As a result, the average number of particles was 12. In addition, the number of sudden particle generations was four.

(Fifth comparative example)
Next, a fifth comparative example in the manufacturing method of the backing plate 1 will be described.

  In the fifth comparative example, the blast process (step 2), the etching process (step 4), and the ultrasonic cleaning after the etching process (step 5) are not performed. That is, the backing plate 1 is only subjected to ultrasonic cleaning (step 3).

The surface roughness (Ra) of the blasting part 5 of the backing plate 1 manufactured under such conditions is 0.5 μm, and the blasting material having an equivalent circle diameter of 10 μm or more remaining in the blasting part 5 is 1 cm ^2. The average was 0 per unit.

  A thin film was formed by the sputtering apparatus 100 and the particles mixed in the thin film were measured. As a result, the average number of particles was 8. The number of sudden particle generations was three.

(Sixth comparative example)
Next, a sixth comparative example in the method for manufacturing the backing plate 1 will be described.

In the sixth comparative example, the average diameter of the equivalent circle diameter of the blasting blast material was 200 μm to 400 μm, and the air pressure of the blasting apparatus was 4.4 kg / cm ² .

  Furthermore, in the sixth comparative example, the ultrasonic frequency was set to 30 kHz in the ultrasonic cleaning after the blasting process (step 3) and the ultrasonic cleaning after the etching process (step 5).

The surface roughness (Ra) of the blasting part 5 of the backing plate 1 manufactured under such conditions is 2.8 μm, and the blasting material having a circle equivalent diameter of 10 μm or more remaining in the blasting part 5 is 1 cm ^2. The average number per unit was 10.

  A thin film was formed by the sputtering apparatus 100, and the particles mixed in the thin film were measured. As a result, the average number of particles was 7. The number of sudden particle generations was three.

(Seventh comparative example)
Next, a seventh comparative example in the method for manufacturing the backing plate 1 will be described.

  In this seventh comparative example, the blasting blast material had an average equivalent circle diameter of 200 μm to 400 μm.

In the ultrasonic cleaning after blasting (step 3) and the ultrasonic cleaning after etching (step 5), the frequency of the ultrasonic wave was set to 30 kHz. Further, instead of the etching process (step 4), the blast processing unit 5 was jet-cleaned with the cleaning liquid. In this case, the discharge pressure of the cleaning liquid was 250 kgf / cm ² and the amount of water was 20 l / min.

The surface roughness (Ra) of the blasting part 5 of the backing plate 1 manufactured under such conditions is 2.7 μm, and the blasting material having a circle equivalent diameter of 10 μm or more remaining in the blasting part 5 is 1 cm ^2. The average was 12 pieces.

  A thin film was formed by the sputtering apparatus 100, and the particles mixed in the thin film were measured. As a result, the average number of particles was 7. The number of sudden particle generations was three.

It is a schematic diagram which shows the sputtering device which concerns on one embodiment of this invention. It is an enlarged view of the sputtering cathode which a sputtering device has, and the shield vicinity. It is a disassembled perspective view of a sputter cathode. It is a flowchart which shows the manufacturing method of the backing plate which concerns on one Embodiment of this invention. It is a schematic diagram which shows an example of a washing | cleaning apparatus. It is a figure for comparing the material, surface roughness, etc. of the backing plate from 1st Embodiment to 8th Embodiment and from 1st Comparative Example to 7th Comparative Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Backing plate 2 ... Sputtering target 3 ... Formation area 5 ... Blast processing part 10 ... Sputtering cathode 20 ... Vacuum chamber 100 ... Sputtering apparatus

Claims (7)

A method of manufacturing a backing plate for holding a sputtering target,
Prepare the backing plate body,
Forming a blasting portion by blasting at least a part of the backing plate body other than the formation region where the sputtering target is formed,
Ultrasonically cleaning the blasting unit;
Etching the ultrasonically cleaned blasting part, or jet cleaning with a cleaning liquid,
A method for manufacturing a backing plate, wherein the blasting unit is ultrasonically cleaned again. It is a manufacturing method of the backing plate according to claim 1,
The step of forming the blast processing part is a method of manufacturing a backing plate in which the blast processing part is roughened to a surface roughness (Ra) of 1 μm to 4 μm. It is a manufacturing method of the backing plate according to claim 2,
The ultrasonic cleaning step is a method of manufacturing a backing plate in which the blast treatment unit is ultrasonically cleaned with a jet of cleaning liquid to which ultrasonic waves of 18 kHz to 19 kHz are applied. It is a manufacturing method of the backing plate according to claim 3,
The manufacturing method of the backing plate which makes the pressure of the said jet flow 200 to 300 kPa. Ultrasonic cleaning the blasting part formed by blasting the backing plate,
Etching the ultrasonically cleaned blasting part, or jet cleaning with a cleaning liquid,
A method for cleaning a backing plate, wherein the blasting unit is ultrasonically cleaned again. A method for cleaning a backing plate according to claim 5 ,
The ultrasonic cleaning step is a cleaning method of a backing plate in which the blasting unit is ultrasonically cleaned with a jet of cleaning liquid to which ultrasonic waves of 18 kHz to 19 kHz are applied. A method for cleaning a backing plate according to claim 5 ,
A method for cleaning a backing plate, wherein the pressure of the jet is 200 kPa or more and 300 kPa or less.

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