JP7488135B2 - Sputtering target and method for manufacturing sputtering target - Google Patents

Description

The present invention relates to a sputtering target and a method for manufacturing a sputtering target.

Oxides such as aluminum oxide (alumina) are used in semiconductor manufacturing equipment and semiconductor devices because of their excellent electrical insulation, heat resistance, and chemical stability. To form an oxide film on a substrate, for example, a sputtering method is used. For example, an oxide target material is placed opposite the substrate, and sputtering particles are emitted from the target material toward the substrate to form an oxide film on the substrate. In addition, the outer periphery of the target material is generally surrounded by a jig called an adhesion prevention plate.

Here, the oxide has insulating properties. Therefore, if discharge occurs during sputtering between the backing plate, which has a lower resistance than the oxide, and the adhesion shield, components other than the oxide may be sputtered, resulting in the inclusion of foreign matter in the oxide film. Furthermore, discharge may occur not only between the backing plate and the adhesion shield, but also between the backing plate and the bonding material (the bonding material that bonds the target material and the backing plate).

To address this issue, a technique has been proposed in which an insulating layer covers the area from the backing plate to the side of the target material (see, for example, Patent Document 1). With this configuration, the surface of the backing plate and the end of the bonding material are covered with an insulating layer, so discharges between the backing plate and the protection plate, or between the bonding material and the protection plate, are suppressed. Furthermore, this technique increases the adhesion of the insulating layer by roughening the side of the backing plate, preventing peeling of the insulating layer.

International Publication No. 2016/021101

However, in the above configuration, although the backing plate is roughened, the side surface of the target material is not roughened.

Here, the target material faces the substrate, so it is heated by the plasma and cooled by the backing plate after film formation is complete. This causes the stress applied between the target material and the insulating layer to vary depending on the thermal history. Furthermore, when target components are redeposited on the insulating layer during sputtering, stress from the redeposited film is applied to the insulating layer.

Therefore, even if the backing plate is roughened, it cannot be said that there is no longer a possibility of the insulating layer peeling off from the target material. If peeling does occur, the backing plate or bonding material will be exposed from under the insulating layer, and ultimately foreign matter will become mixed into the oxide film.

In view of the above circumstances, the object of the present invention is to provide a sputtering target having a structure in which an insulating layer covers the entire surface from the backing plate to the side surface of the sputtering target, in which the insulating layer is less likely to peel off from the target material, and a method for manufacturing the sputtering target.

In order to achieve the above object, a sputtering target according to one embodiment of the present invention includes an oxide target material, a substrate, a bonding member, and an insulating layer.
The oxide target material has a first main surface which is a sputtering surface, a second main surface opposite to the first main surface, and a side surface connected to the first main surface and the second main surface.
The substrate is provided on the second main surface side of the oxide target material.
The bonding member is provided between the base material and the oxide target material, and bonds the base material and the oxide target material.
The insulating layer is provided from at least a portion of the side surface of the oxide target material, across the bonding member, to at least a portion of the surface of the base material.
The insulating layer has contact surfaces with the oxide target material, the joining member, and the base material, each of which is subjected to a blasting treatment.

With such a sputtering target, the contact surfaces of the insulating layer that contact the oxide target material, the bonding member, and the base material are each subjected to a blasting treatment, resulting in a sputtering target in which the insulating layer is less likely to peel off from the target material.

In the above sputtering target, the contact surface may have an arithmetic mean roughness of 8 μm or more and 20 μm or less.

With such a sputtering target, the contact surface has an arithmetic mean roughness of 8 μm or more and 20 μm or less, resulting in a sputtering target in which the insulating layer is less likely to peel off from the target material.

In the above sputtering target, the adhesion between the insulating layer and the oxide target material may be 3 MPa or more.

With such a sputtering target, the adhesion between the insulating layer and the oxide target material is 3 MPa or more, resulting in a sputtering target in which the insulating layer is less likely to peel off from the target material.

In the above sputtering target, the thickness of the insulating layer may be 100 μm or more and 300 μm or less.

With such a sputtering target, the insulating layer has a thickness of 100 μm or more and 300 μm or less, resulting in a sputtering target in which the insulating layer is less likely to peel off from the target material.

In order to achieve the above-mentioned object, in a method for manufacturing a sputtering target according to one embodiment of the present invention, a target is prepared having an oxide target material having a first main surface which is a sputtering surface, a second main surface opposite the first main surface, and a side surface connected to the first main surface and the second main surface, a substrate provided on the side of the second main surface of the oxide target material, and a joining member provided between the substrate and the oxide target material and joining the substrate and the oxide target material.
Insulating particles are sprayed from at least a portion of the side surface of the oxide target material, across the joining member, to at least a portion of the surface of the base material.
An insulating material is sprayed onto the blasted surface onto which the insulating particles have been sprayed, thereby forming an insulating layer on the blasted surface.

With this manufacturing method, the contact surface is blasted, resulting in a sputtering target in which the insulating layer is less likely to peel off from the target material.

In the above-mentioned method for manufacturing a sputtering target, the blasted surface may have an arithmetic mean roughness of 8 μm or more and 20 μm or less.

This manufacturing method results in a sputtering target in which the contact surface has an arithmetic mean roughness of 8 μm or more and 10 μm or less, making the insulating layer less likely to peel off from the target material.

In the above-mentioned method for manufacturing a sputtering target, the insulating particles may have an average particle size of 125 μm or more and 180 μm or less.

According to this manufacturing method, the blasting process is performed using insulating particles with an average particle size of 125 μm or more and 180 μm or less, resulting in a sputtering target in which the insulating layer is less likely to peel off from the target material.

In the method for manufacturing the sputtering target, the insulating particles may be ejected from a nozzle set to an internal pressure of 0.4 MPa or more and 1.0 MPa or less to form the blasted surface.

This manufacturing method provides a sputtering target in which the insulating layer is less likely to peel off from the target material because the adhesion between the insulating layer and the oxide target material is 3 MPa or more.

As described above, the present invention provides a sputtering target having a structure in which the surface of the backing plate and the side of the sputtering target are covered with an insulating layer, in which the insulating layer is less likely to peel off from the target material, and a method for manufacturing the sputtering target.

FIG. 1 is a schematic cross-sectional view showing an example of a film forming apparatus. 2 is a schematic cross-sectional view showing the outer periphery of a target 30 according to the present embodiment. 5A to 5C are schematic cross-sectional views showing a method for manufacturing a target. FIG. 11 is a schematic cross-sectional view showing a modified example of the target of the present embodiment. FIG. 11 is a schematic cross-sectional view showing another modified example of the target of the present embodiment.

Below, an embodiment of the present invention will be described with reference to the drawings. XYZ axis coordinates may be introduced in each drawing. In addition, the same reference numerals may be used to refer to the same components or components having the same functions, and after describing the components, the description may be omitted as appropriate.

An example of a film forming apparatus in which the sputtering target of this embodiment is used will be described. Figure 1 is a schematic cross-sectional view showing an example of the film forming apparatus.

The film forming apparatus 1 comprises a vacuum vessel 10, a support table 20, a sputtering target 30 (target assembly), an adhesion prevention plate 40, a magnetic circuit section 50, a power supply 60, an exhaust mechanism 70, and a gas supply mechanism 75. A substrate 21, which is the object to be processed, is placed on the support table 20.

The vacuum vessel 10 is a vessel capable of maintaining a reduced pressure state. An exhaust mechanism 70, such as a vacuum pump and a valve, is connected to the vacuum vessel 10 through piping 71. The exhaust mechanism 70 maintains the atmosphere inside the vacuum vessel 10 at a predetermined pressure. A gas supply mechanism 75, such as a flow meter and a valve, is installed in the vacuum vessel 10 through an introduction pipe 76. The gas supply mechanism 75 supplies a discharge gas into the vacuum vessel 10. The discharge gas is, for example, an inert gas (Ar, Ne, He, etc.). A pressure gauge that measures the pressure inside the vacuum vessel 10 may also be installed in the vacuum vessel 10.

The support table 20 is installed in the vacuum vessel 10. The substrate 21 is supported by the support table 20. A film formation process is performed on the substrate 21. The support table 20 has a mounting surface on which the substrate 21 is placed that may be a conductor or an insulator. For example, an electrostatic chuck may be installed on the mounting surface. The support table 20 may have a built-in temperature adjustment mechanism that keeps the substrate 21 at a predetermined temperature. The substrate 21 is changed as appropriate depending on the device to which it is applied, and may be, for example, a glass substrate, an insulating substrate such as a quartz substrate, a semiconductor substrate such as a silicon wafer, a metal substrate, or the like.

The sputtering target 30 (hereinafter, target 30) is placed in the vacuum vessel 10 via the insulator 11. The target 30 is arranged so as to face the support table 20. The target material contained in the target 30 is changed as appropriate depending on the composition of the film to be formed on the substrate 21. For example, the target material is an oxide target material such as an aluminum oxide material or a silicon oxide material. The planar shape of the oxide target material is adjusted as appropriate to correspond to the planar shape of the substrate 21. The structure of the target 30 will be described later.

The adhesion prevention plate 40 is annular and, for example, when the film formation apparatus 1 is viewed from above, surrounds the outer periphery of the target 30. For example, the adhesion prevention plate 40 is placed in the vacuum vessel 10 along the target 30, leaving the sputtering surface 31s of the target 30 open. The adhesion prevention plate 40 is, for example, fixed to the upper part of the vacuum vessel 10. A gap of, for example, 0.5 mm to several mm is provided between the adhesion prevention plate 40 and the target 30. The potential of the adhesion prevention plate 40 is set to ground potential. As a result, Paschen's law operates during film formation, and plasma gathers near the sputtering surface 31s, maintaining a stable plasma discharge.

The magnetic circuit unit 50 is disposed on the back side of the target 30 opposite the support stand 20. The magnetic circuit unit 50 has a yoke 51 disposed parallel to the target 30, and a magnet 52 provided on the yoke 51. The magnet 52 is disposed so as to face the back side of the target 30 opposite the sputtering surface 31s.

As a result, the magnetic field emitted from the magnets 52 leaks near the sputtering surface 31s, and electrons in the plasma are captured by the leaked magnetic field. This creates a high-density plasma near the sputtering surface 31s, and so-called magnetron sputtering is performed. The shape and number of the magnets 52 are appropriately adjusted from the viewpoints of discharge stability, the in-plane distribution of the film layer on the substrate 21, or improving the efficiency of use of the target 30.

The power supply 60 is connected to the target 30 via a line 61. The power supply 60 supplies power to the target 30. The power supply 60 may be a DC power supply, a VHF power supply, or an RF power supply. When the power supply 60 is a high-frequency power supply such as a VHF power supply or an RF power supply, a matching circuit may be provided in the line 61 between the power supply 60 and the target 30.

When a discharge gas is introduced into the vacuum vessel 10 and a predetermined power is applied to the target 30 from the power source 60, a discharge plasma is generated near the sputtering surface 31s due to capacitive coupling. When ions in the discharge plasma collide with the sputtering surface 31s and the sputtering surface 31s is sputtered by the ions, sputtering particles are scattered from the sputtering surface 31s toward the substrate 21. As a result, a film in which the sputtering particles are deposited to a predetermined thickness is formed on the substrate 21.

Figure 2 is a schematic cross-sectional view showing the target of this embodiment. Figure 2 shows the outer periphery of the target 30.

The target 30 comprises an oxide target material 31, which is the target body, a substrate 32, a joining member 33, and a sprayed insulating layer 34, which is an insulating layer.

The oxide target material 31 has a sputtering surface 31s, a back surface 31r opposite to the sputtering surface 31s, and a side surface 31w connected to the sputtering surface 31s and the back surface 31r. In this embodiment, the sputtering surface 31s is the first main surface of the oxide target material 31, and the back surface 31r is the second main surface of the oxide target material 31. The oxide target material 31 is an oxide sintered body.

The substrate 32 is a backing plate and is provided on the back surface 31r side of the oxide target material 31. The substrate 32 has a portion 321 that contacts the insulator 11 and a portion 322 that has a smaller diameter than the portion 321. The portions 321 and 322 are made of the same material and are integrally constructed.

Since the substrate 32 has parts 321 and 322 with different diameters, the substrate 32 has a convex shape with part 322 protruding from part 321. In other words, a step is formed in the substrate 32 by parts 321 and 322. The outer diameter of part 322 is, for example, approximately the same as the diameter of the oxide target material 31. A flow path for flowing a coolant may be provided inside the substrate 32.

The joining member 33 is provided between the oxide target material 31 and the base material 32. The joining member 33 tightly joins the oxide target material 31 and the base material 32. The joining member 33 is, for example, a brazing material such as indium.

The sprayed insulating layer 34 is provided on at least a portion of the target 30 other than the sputtering surface 31s. For example, the sprayed insulating layer 34 is provided continuously from at least a portion of the side surface 31w of the oxide target material 31, across the joining member 33, to at least a portion of the surface of the substrate 32.

The thickness of the sprayed insulation layer 34 is 100 μm or more and 300 μm or less, for example, 150 μm or more, for example, 200 μm. As a result, even if voids are formed inside the sprayed insulation layer 34, the insulation properties of the sprayed insulation layer 34 are ensured because the sprayed insulation layer 34 has a thickness of 150 μm or more.

The contact surface 300 where the sprayed insulating layer 34 contacts the target 30 includes a contact surface 310, a contact surface 330, and a contact surface 320. The contact surface 310 is formed on at least a part of the side surface 31w of the oxide target material 31. The contact surface 330 is formed on the end surface of the joining member 33. The contact surface 320 is formed on the surface of the base material 32 that is not in contact with the joining member 33. The contact surfaces 310, 330, and 320 are each connected to each other.

The sprayed insulating layer 34 may be made of the same material as the oxide target material 31, or may be made of a different material from the oxide target material 31. For example, the sprayed insulating layer 34 may be made of a plasma-resistant material such as alumina, alumina titanate, aluminum nitride, or yttria, but is not limited to these. Even if the sprayed insulating layer 34 and the oxide target material 31 are made of the same material, the boundary between the sprayed insulating layer 34 and the oxide target material 31 can be visually determined. For example, the oxide target material 31 has a smooth surface machined on the sintered body surface, while the sprayed insulating layer 34 has an uneven shape unique to a sprayed film, so it is possible to determine whether it is the sprayed insulating layer 34 or the oxide target material 31.

The contact surface 300 is blasted with insulating particles. If the conditions for blasting the side surface 31w are not appropriate, the side surface 31w will be eroded by the insulating particles, and it has been very difficult to achieve the desired surface roughness of 8 μm or more.

In contrast, in this embodiment, for example, the contact surface 300 is set to an arithmetic mean roughness Ra of 8 μm or more and 20 μm or less. In particular, the contact surface 310 of the oxide target material 31 has an arithmetic mean roughness Ra of 8 μm or more and 20 μm or less. Here, if the arithmetic mean roughness Ra of the contact surface 310 is smaller than 8 μm, the adhesion between the sprayed insulating layer 34 and the oxide target material 31 is weakened, which is not preferable. On the other hand, if the arithmetic mean roughness Ra of the contact surface 310 is larger than 20 μm, the surface roughness of the oxide target material 31, which is a sintered body, is large, and the crystal grains constituting the sintered body fall off from the contact surface 310, which is not preferable. In addition, the adhesion between the sprayed insulating layer 34 and the oxide target material 31 is 3 MPa or more, for example, 10 MPa.

The manufacturing method of the target 30 will now be described. Figures 3(a) and (b) are schematic cross-sectional views showing the manufacturing method of the target.

As shown in FIG. 3(a), a target 30 is prepared, which includes an oxide target material 31, a substrate 32, and a bonding member 33. A mask 90 is applied to cover the oxide target material 31 from the sputtering surface 31s to a portion of the side surface 31w.

Next, the target 30 is fixed to the rotating table 95 so that the substrate 32 of the target 30 faces the rotating table 95. If appropriate, the surface of the substrate 32 facing the rotating table 95 may also be covered with a mask 91. An example of this is shown in FIG. 3(a). However, this embodiment also includes an example in which the mask 91 is removed. In this case, the target 30 is fixed to the rotating table 95 so that there is no gap between the substrate 32 and the rotating table 95.

Next, the nozzle 97 is placed facing the outer periphery of the target 30 that has been released from the masks 90 and 91. For example, the nozzle 97 is placed facing at least a portion of the surface 32s of the substrate 32 across the joining member 33 from at least a portion of the side surface 31w of the oxide target material 31. The nozzle-to-target distance (the shortest distance between the tip of the nozzle 97 and the target 30) is 100 mm or more and 200 mm or less, for example, 170 mm.

Next, while the rotating table 95 rotates, insulating particles are ejected from the nozzle 97 and sprayed toward the target 30. For example, the insulating particles are sprayed onto the outer peripheral region of the target 30 that is released from the masks 90 and 91, that is, the region from at least a portion of the side surface 31w of the oxide target material 31 across the joining member 33 to at least a portion of the surface 32s of the substrate 32.

For example, alumina particles are used as the insulating particles. The average particle size of the alumina particles is 125 μm or more and 180 μm or less. The alumina particles are sprayed from a nozzle 97 set to an internal pressure of 0.4 MPa or more and 1.0 MPa or less, for example, 0.6 MPa. After spraying, the insulating particles are removed from the blasted surface by air blowing, suction, or other techniques.

As a result, as shown in FIG. 3(b), an uneven blasted surface, i.e., the contact surface 300, is formed on the outer peripheral region of the target 30 that has been released from the masks 90 and 91. After this, the insulating material that is the raw material of the sprayed insulating layer 34 is sprayed onto the blasted surface (contact surface 300) by a thermal spraying method, and the sprayed insulating layer 34 is formed on the blasted surface (FIG. 2).

According to this embodiment, even if there is a gap between the target 30 and the adhesion prevention plate 40, the sprayed insulating layer 34 is interposed between the adhesion prevention plate 40 and the target 30. Therefore, abnormal discharge is unlikely to occur between the target 30 and the adhesion prevention plate 40.

In particular, since the oxide target material 31 is located on the outermost surface of the target 30, the sputtering surface 31s is heated by the plasma and the back surface 31r is cooled by the substrate 32. As a result, stress is applied between the sprayed insulating layer 34 and the oxide target material 31 in the target 30 according to the thermal history.

According to this embodiment, the side surface 31w of the oxide target material 31 is roughened, and the adhesion between the sprayed insulating layer 34 and the oxide target material 31 is improved mainly by the anchor effect. As a result, even if a film is reattached from the oxide target material 31 to the sprayed insulating layer 34 during sputtering, the adhesion between the sprayed insulating layer 34 and the oxide target material 31 overcomes the stress of this film, and the sprayed insulating layer 34 adheres firmly to the oxide target material 31.

As a result, abnormal discharge between the target 30 and the shielding plate 40 is suppressed for a long period of time, and the target life can be extended. Furthermore, the productivity of devices using the target 30 is improved.

(Comparative Example)

Figure 4 is a schematic cross-sectional view showing a comparative example of a target.

As described above, depending on the spraying conditions, the insulating particles 80 may erode into the side surface 31w, and the insulating particles 80 may remain on the contact surface 310.

In such a configuration, the adhesion strength of the sprayed insulating layer 34 to the target 30 is weakened, which is undesirable. In contrast, in this embodiment, as few insulating particles 80 as possible are left on the contact surface 310, and the surface roughness Ra is adjusted to be 8 μm or more and 20 μm or less.

Figures 5(a) and (b) are schematic cross-sectional views showing another modified example of the target of this embodiment.

In the oxide target material 31, a recess 350 (FIG. 5(a)) or a protrusion 351 (FIG. 5(b)) may be provided on the side surface 31w. For example, the recess 350 is a region recessed from the contact surface 310 into the oxide target material 31, and the protrusion 351 is a region protruding from the contact surface 310 into the sprayed insulation layer 34.

With this configuration, the anchor effect at the interface between the sprayed insulation layer 34 and the oxide target material 31 is further promoted, and the sprayed insulation layer 34 adheres more firmly to the target 30.

(Blast processing)

In this embodiment, the surface roughness of the side surface 31w of the oxide target material 31 was controlled by adjusting the blasting conditions (roughness of the blast particles, ejection pressure, number of passes) and optimizing the plasma spraying conditions (distance), resulting in a target 30 in which the sprayed insulating layer 34 is less likely to peel off from the oxide target material 31. The surface roughness Ra was evaluated using a stylus surface roughness measuring instrument (Tokyo Seimitsu Co., Ltd., model number: SURFCOM TOUCH50) under the conditions specified in JIS B0601 (1994).

(Adhesion evaluation)

The adhesion strength was measured by spraying a thermally sprayed insulating layer onto an oxide target piece, adhering an alumina rod to the thermally sprayed insulating layer, and pulling the rod. The adhesion strength of the thermally sprayed insulating layer to the oxide target piece was measured while changing the conditions for blasting the surface of the oxide target piece and the spraying conditions for the thermally sprayed insulating layer. For example, the adhesion strength was evaluated using a pull-off adhesion tester (manufactured by ELCOMETER, model number: 510) under the conditions specified in JIS K5600-5-7.

(peeling evaluation)

Peeling was evaluated based on the presence or absence of abnormal discharge and the state of peeling as seen visually, divided into four stages. For example, A: no peeling, no abnormal discharge traces, B: no peeling, but abnormal discharge traces, C: peeling, abnormal discharge traces, D: cracks occurred on the target.

The results are shown in Table 1.

The particle size in this embodiment is defined as the particle size, and the particle size was measured using a mesh sieve specified in JIS Z8801-1, taking a sample of about 300 g, and measuring it according to JIS 8815. The average particle size was evaluated using the average particle size of the blasting material specified in JIS R 6001-1:2017.

(Example 1)

A target consisting of three components was created: an alumina target material with a purity of 4N, a diameter of 300 mm, and a thickness of 6 mm, and an oxygen-free copper backing plate joined together with an indium solder material with a thickness of 0.5 mm.

The inside of the target is covered with a resin tape that has excellent heat resistance and abrasion resistance, spanning from part of the side of the target material across the indium solder material to the surface of the backing plate (excluding the back surface).

The target was placed on the rotating table of the blasting device, and while rotating at a specified speed, the target was blasted using alumina particles with an average particle size of 125 to 180 μm. The nozzle pressure was 0.6 MPa. The number of passes was 40.

The alumina particles adhering to the blasted surface were removed. The arithmetic mean roughness Ra of the blasted surface at this time was 19.2 μm. The target was placed on the rotary table of the plasma spraying machine and rotated at a specified speed while spraying was performed using alumina particles with an average particle size of 30 μm. The nozzle-target distance was 150 mm. The thickness of the sprayed insulating layer was 190 μm. During spraying, the indium brazing material was cooled by air blowing to prevent it from softening due to plasma heat. The adhesion strength of the sprayed insulating layer to the target material was 8.1 MPa.

This target was attached to a sputtering device and subjected to continuous discharge for 96 hours at a power of 3 kW. After the continuous discharge, black deposits, thought to be redeposited films, had accumulated on the sprayed insulation layer, but no abnormal discharge marks or peeling of the sprayed film were observed. The evaluation was an A.

(Example 2)

As in Example 1, a target covered with a resin tape was prepared, and alumina particles with an average particle size of 125 to 180 μm were used to blast the target at a nozzle pressure of 0.4 MPa, the lowest among Examples 1 to 4. The number of passes was 40.

As in Example 1, the alumina particles adhering to the blasted surface were removed. The arithmetic mean roughness Ra of the blasted surface at this time was 8.0 μm. Thermal spraying was performed using alumina particles with an average particle size of 30 μm as the target, with the nozzle-to-target distance being 150 mm. The thickness of the thermal sprayed insulation layer was 200 μm. The adhesion strength of the thermal sprayed insulation layer to the target material was 3.2 MPa.

This target was attached to a sputtering device and subjected to continuous discharge for 96 hours at a power of 3 kW. After the continuous discharge, black deposits, thought to be redeposited films, had accumulated on the sprayed insulation layer, but no abnormal discharge marks or peeling of the sprayed film were observed. The evaluation was an A.

(Example 3)

As in Example 1, a target covered with a resin tape was prepared, and the target was blasted at a nozzle pressure of 0.6 MPa using alumina particles with an average particle size of 125 to 180 μm. The number of passes was 40.

As in Example 1, the alumina particles adhering to the blasted surface were removed. The arithmetic mean roughness Ra of the blasted surface at this time was 19.2 μm. Thermal spraying was performed at a nozzle-to-target distance of 200 mm using alumina particles with an average particle size of 30 μm as the target. The sprayed insulation layer was formed thin, with a thickness of 140 μm. The adhesion strength of the sprayed insulation layer to the target material was 12.0 MPa.

This target was attached to a sputtering device and subjected to continuous discharge for 96 hours at a power of 3 kW. After the continuous discharge, black deposits, thought to be redeposited films, had accumulated on the sprayed insulation layer, but no abnormal discharge marks or peeling of the sprayed film were observed, even with such a thin film thickness. The evaluation was an A.

(Example 4)

As in Example 1, a target covered with a resin tape was prepared, and the target was blasted at a nozzle pressure of 0.6 MPa using alumina particles with an average particle size of 125 to 180 μm. The number of passes was 40.

As in Example 1, the alumina particles adhering to the blasted surface were removed. The arithmetic mean roughness Ra of the blasted surface at this time was 19.2 μm. Thermal spraying was performed with a nozzle-to-target distance of 100 mm using alumina particles with an average particle size of 30 μm as the target. The sprayed insulation layer was formed thick, with a thickness of 300 μm. The adhesion strength of the sprayed insulation layer to the target material was 5.0 MPa.

This target was attached to a sputtering device and subjected to continuous discharge for 96 hours at a power of 3 kW. After the continuous discharge, black deposits, thought to be redeposited films, had accumulated on the sprayed insulation layer, but there were no abnormal discharge marks, and no peeling was observed, even with such a thick sprayed film. The evaluation was A.

(Comparative Example 1)

As in Example 1, a target covered with a resin tape was prepared, and the target was blasted at a nozzle pressure of 1.0 MPa using alumina particles with an average particle size of 90 to 125 μm, which is smaller than those in Examples 1 to 4. The number of passes was 80.

As in Example 1, the alumina particles adhering to the blasted surface were removed. When alumina particles with an average particle size of 90 to 125 μm were used, the arithmetic mean roughness Ra of the blasted surface was 6.0 μm. Alumina particles with an average particle size of 30 μm were used as the target, and thermal spraying was performed with a nozzle-to-target distance of 150 mm. The thickness of the thermal sprayed insulation layer was 200 μm. The adhesion strength of the thermal sprayed insulation layer to the target material was 2.1 MPa.

This target was attached to a sputtering device and subjected to continuous discharge for 96 hours at a power of 3 kW. After the continuous discharge, black deposits, thought to be redeposited films, had accumulated on the sprayed insulation layer, but no abnormal discharge marks or peeling of the sprayed film were observed. However, black discolored areas indicating abnormal discharge were observed.

This target was attached to a sputtering device and subjected to continuous discharge for 96 hours at a power of 3 kW. After the continuous discharge, black deposits, believed to be redeposited films, had accumulated on the sprayed insulation layer, and abnormal discharge marks and peeling of the sprayed film were confirmed. The evaluation was C.

(Comparative Example 2)

As in Example 1, a target covered with a resin tape was prepared, and the target was blasted at a nozzle pressure of 0.6 MPa using alumina particles with an average particle size of 125 to 180 μm. The number of passes was 80.

As in Example 1, the alumina particles adhering to the blasted surface were removed. The arithmetic mean roughness Ra of the blasted surface at this time was roughly formed, being 29.0 μm. Thermal spraying was performed at a nozzle-to-target distance of 150 mm using alumina particles with an average particle size of 30 μm as the target. The thickness of the thermal sprayed insulation layer was 200 μm. The adhesion strength of the thermal sprayed insulation layer to the target material was 1.4 MPa.

This target was attached to a sputtering device and subjected to continuous discharge for 96 hours at a power of 3 kW. After the continuous discharge, black deposits, believed to be redeposited films, had accumulated on the sprayed insulation layer, and abnormal discharge marks and peeling of the sprayed film were confirmed. The evaluation was C.

(Comparative Example 3)

As in Example 1, a target covered with a resin tape was prepared, and alumina particles with an average particle size of 125 to 180 μm were used to blast the target at a nozzle pressure of 1.2 MPa. The number of passes was 5. Even with a small number of passes, cracks were observed in the target after blasting when the nozzle pressure was so high. The evaluation was D.

(Comparative Example 4)

As in Example 1, a target covered with a resin tape was prepared, and the target was blasted at a nozzle pressure of 0.6 MPa using alumina particles with an average particle size of 125 to 180 μm. The number of passes was set low, at 10.

As in Example 1, the alumina particles adhering to the blasted surface were removed. The arithmetic mean roughness Ra of the blasted surface at this time was 6.9 μm. Thermal spraying was performed at a nozzle-to-target distance of 150 mm using alumina particles with an average particle size of 30 μm as the target. The thickness of the thermal sprayed insulation layer was 200 μm. The adhesion strength of the thermal sprayed insulation layer to the target material was 2.5 MPa.

This target was attached to a sputtering device and subjected to continuous discharge for 96 hours at a power of 3 kW. With such a low number of passes, black deposits thought to be redeposited films accumulated on the sprayed insulation layer after continuous discharge, and abnormal discharge marks and peeling of the sprayed film were confirmed. The evaluation was C.

(Comparative Example 5)

As in Example 1, a target covered with a resin tape was prepared, and alumina particles with an average particle size of 125 to 180 μm were used. The nozzle pressure was set low, and the target was blasted at a nozzle pressure of 0.2 MPa. The number of passes was 80.

As in Example 1, the alumina particles adhering to the blasted surface were removed. The arithmetic mean roughness Ra of the blasted surface at this time was 5.0 μm. Thermal spraying was performed at a nozzle-to-target distance of 150 mm using alumina particles with an average particle size of 30 μm as the target. The thickness of the thermal sprayed insulation layer was 200 μm. The adhesion strength of the thermal sprayed insulation layer to the target material was 1.8 MPa.

This target was attached to a sputtering device and continuous discharge was performed for 96 hours at a power of 3 kW. When the nozzle pressure was low, black deposits that appeared to be redeposited films accumulated on the sprayed insulation layer after continuous discharge, and abnormal discharge marks and peeling of the sprayed film were confirmed. The evaluation was C.

(Comparative Example 6)

As in Example 1, a target covered with a resin tape was prepared, and the target was blasted at a nozzle pressure of 0.6 MPa using alumina particles with an average particle size of 212 to 300 μm. The number of passes was 80.

As in Example 1, the alumina particles adhering to the blasted surface were removed. However, because the particle size of the alumina particles was large, the arithmetic mean roughness Ra of the blasted surface was 5.1 μm. Thermal spraying was performed with a nozzle-to-target distance of 150 mm using alumina particles with an average particle size of 30 μm as the target. The thickness of the thermal sprayed insulation layer was 200 μm. The adhesion strength of the thermal sprayed insulation layer to the target material was 1.2 MPa.

This target was attached to a sputtering device and subjected to continuous discharge for 96 hours at a power of 3 kW. After the continuous discharge, black deposits, believed to be redeposited films, had accumulated on the sprayed insulation layer, and abnormal discharge marks and peeling of the sprayed film were confirmed. The evaluation was C.

(Comparative Example 7)

As in Example 1, a target covered with a resin tape was prepared, and the target was blasted at a nozzle pressure of 0.6 MPa using alumina particles with an average particle size of 500 to 710 μm. The number of passes was 80.

As in Example 1, the alumina particles adhering to the blasted surface were removed. However, because the particle size of the alumina particles was large, the arithmetic mean roughness Ra of the blasted surface was 3.0 μm. Thermal spraying was performed with a nozzle-to-target distance of 150 mm using alumina particles with an average particle size of 30 μm as the target. The thickness of the thermal sprayed insulation layer was 200 μm. The adhesion strength of the thermal sprayed insulation layer to the target material was 0.6 MPa.

This target was attached to a sputtering device and subjected to continuous discharge for 96 hours at a power of 3 kW. After the continuous discharge, black deposits, believed to be redeposited films, had accumulated on the sprayed insulation layer, and abnormal discharge marks and peeling of the sprayed film were confirmed. The evaluation was C.

(Comparative Example 8)

As in Example 1, a target covered with a resin tape was prepared, and the target was blasted at a nozzle pressure of 0.6 MPa using alumina particles with an average particle size of 125 to 180 μm. The number of passes was 40.

As in Example 1, the alumina particles adhering to the blasted surface were removed. The arithmetic mean roughness Ra of the blasted surface at this time was 19.2 μm. Thermal spraying was performed at a nozzle-to-target distance of 75 mm using alumina particles with an average particle size of 30 μm as the target. The sprayed insulation layer was formed thick, with a thickness of 340 μm. The adhesion strength of the sprayed insulation layer to the target material was 2.3 MPa.

This target was attached to a sputtering device and subjected to continuous discharge for 96 hours at a power of 3 kW. After the continuous discharge, black deposits, believed to be redeposited films, had accumulated on the sprayed insulation layer, and abnormal discharge marks and peeling of the sprayed film were confirmed. The evaluation was C.

(Comparative Example 9)

As in Example 1, a target covered with a resin tape was prepared, and the target was blasted with alumina particles having an average particle size of 125 to 180 μm at a nozzle pressure of 0.6 MPa. The number of passes was 40.

As in Example 1, the alumina particles adhering to the blasted surface were removed. The arithmetic mean roughness Ra of the blasted surface at this time was 19.2 μm. Thermal spraying was performed at a nozzle-to-target distance of 300 mm using alumina particles with an average particle size of 30 μm as the target. The sprayed insulation layer was formed thin, with a thickness of 90 μm. The adhesion strength of the sprayed insulation layer to the target material was 15.0 MPa.

This target was attached to a sputtering device and subjected to continuous discharge for 96 hours at a power of 3 kW. After the continuous discharge, black deposits, thought to be redeposited films, had accumulated on the sprayed insulation layer, but no peeling of the sprayed film was observed. However, black discolored areas indicating abnormal discharge were observed. The evaluation was given a B.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made. Each embodiment is not necessarily an independent form, and can be combined as far as technically possible.

Reference Signs List 1: Film forming apparatus 10: Vacuum vessel 11: Insulator 20: Support 21: Substrate 30: Target (sputtering target)
31: oxide target material 31s: sputtering surface 31r: back surface 31w: side surface 32: substrate 32s: front surface 33: joining member 34: sprayed insulating layer 40: adhesion prevention plate 50: magnetic circuit section 51: yoke 52: magnet 60: power supply 61: line 70: exhaust mechanism 71: piping 75: gas supply mechanism 76: introduction pipe 80: insulating particles 90, 91: mask 95: rotating table 97: nozzle 300, 310, 320, 330: contact surface 321, 322: part 350: recess 351: protrusion

Claims (6)

an oxide target material having a first main surface which is a sputtering surface, a second main surface opposite to the first main surface, and a side surface connected to the first main surface and the second main surface;
a substrate provided on the second main surface side of the oxide target material;
a bonding member provided between the base material and the oxide target material, the bonding member bonding the base material and the oxide target material;
an insulating layer provided from at least a portion of the side surface of the oxide target material to at least a portion of the surface of the base material across the bonding member;
A sputtering target in which a blasting treatment is performed on contact surfaces of the insulating layer that contact the oxide target material, the bonding member, and the base material,
The adhesion strength between the insulating layer and the oxide target material is 3 MPa or more,
The thickness of the insulating layer is 100 μm or more and 300 μm or less.
Sputtering target. 2. The sputtering target of claim 1,
A sputtering target, wherein the contact surface has an arithmetic mean roughness of 8 μm or more and 20 μm or less. a target including an oxide target material having a first main surface which is a sputtering surface, a second main surface opposite to the first main surface, and a side surface connected to the first main surface and the second main surface, a substrate provided on the second main surface side of the oxide target material, and a bonding member provided between the substrate and the oxide target material and bonding the substrate and the oxide target material;
Insulating particles are sprayed from at least a portion of the side surface of the oxide target material across the bonding members to at least a portion of the surface of the base material;
and spraying an insulating material onto the blasted surface onto which the insulating particles have been sprayed, to form an insulating layer on the blasted surface with a thickness of 100 μm to 300 μm so that the adhesion between the insulating layer and the oxide target material is 3 MPa or more . A method for producing the sputtering target according to claim 3 , comprising the steps of:
The blasted surface has an arithmetic mean roughness of 8 μm or more and 20 μm or less. A method for producing a sputtering target according to claim 3 or 4 , comprising the steps of:
The insulating particles have an average particle size of 125 μm or more and 180 μm or less. A method for producing a sputtering target according to any one of claims 3 to 5 , comprising the steps of:
the insulating particles are ejected from a nozzle whose internal pressure is set to 0.4 MPa or more and 1.0 MPa or less to form the blasted surface.