TW201641728A - Ceramic tube-like target material and tube-like sputtering target - Google Patents

Abstract

An embodiment of a ceramic tube-like target material of this invention has a surface roughness Ra of 1.2 [mu]m or less on the inner periphery.

Description

Ceramic cylindrical target and cylindrical sputtering target

Embodiments disclosed herein relate to ceramic cylindrical targets and cylindrical sputtering targets.

A magneto-type rotary cathode sputtering apparatus is known which has a magnetic field generating device inside a cylindrical target, and cools the target from the inside while further rotating the target while performing sputtering. In such a sputtering apparatus, the entire peripheral surface of the target is corroded and uniformly cut. Therefore, compared with the conventional flat-type magnetron sputtering apparatus, the use efficiency is 20 to 30%, and a very high use efficiency of 70% or more can be obtained in the magneto-type rotary cathode sputtering apparatus.

Further, in the magneto-type rotary cathode sputtering apparatus, sputtering is performed while rotating the target material, so that a large power can be input per unit area compared to the flat-type magnetic particle sputtering apparatus, so that it is possible to obtain High film formation speed.

Such a rotating cathode sputtering method has been widely used in the use of a metal target which is easy to process in a cylindrical shape and has high mechanical strength. In contrast, a ceramic target has a target compared to a metal target. Low mechanical strength and brittle properties.

Further, the coefficient of thermal expansion of the ceramic material is smaller than the coefficient of thermal expansion of the metal material used as the cylindrical support tube, so that the target is likely to cause cracks due to the difference in the amount of thermal expansion of the cylindrical target and the support tube. Therefore, research on cylindrical targets made of ceramics has been taken to overcome these problems.

Patent Document 1 discloses a technique in which a ceramic cylindrical target having a relative density of 95% or more is bonded to a cylindrical sputtering target of a cylindrical substrate by a low melting point solder to suppress cracking during joining. However, countermeasures against cracking of targets in sputtering have not been considered.

Patent Document 2 discloses a technique for controlling the polishing angle of a ceramic cylindrical target and the surface roughness of the outer peripheral surface to suppress cracking generated at the initial stage of sputtering. However, the crack of the target caused by the surface roughness of the outer peripheral surface is extremely short after the start of sputtering, and in the sputtering in this technique, the crack of the target at the end of sputtering cannot be particularly suppressed.

Patent Document 3 discloses a cylindrical sputtering target in which a ceramic cylindrical target and a cylindrical substrate are joined by a bonding material, and the area where the bonding material does not exist is reduced to reduce the sputtering. Techniques for cracking, defects, abnormal discharge, and small agglomeration of targets. However, in the technical content of this document, it is not sufficient to suppress cracking of the ceramic cylindrical target.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2005-281862

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2009-30165

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2010-18883

As described above, the above-described conventional techniques still fail to obtain a ceramic cylindrical target and a cylindrical sputtering target which are excellent in suppressing cracking, and there is still room for further improvement.

In view of the above, it is an object of the present invention to provide a ceramic cylindrical target and a cylindrical sputtering target which can further suppress the occurrence of cracks until the end of the service life.

The surface roughness Ra of the inner peripheral surface of the ceramic cylindrical target of the embodiment is 1.2 μm or less.

According to one aspect of the embodiment, it is possible to provide a ceramic cylindrical target and a cylindrical sputtering target which can further suppress the occurrence of cracks until the end of the service life.

1‧‧‧Cylindrical Sputtering Target (Cylindrical Target)

2‧‧‧Ceramic cylindrical target (cylindrical target)

2a‧‧‧outer surface

2b‧‧‧ inner circumference

2c‧‧‧ both ends

3‧‧‧Support tube

3a‧‧‧ outer perimeter

4‧‧‧Material

Fig. 1 is a schematic view showing the outline of the configuration of a ceramic cylindrical target and a cylindrical sputtering target.

Fig. 2 is a cross-sectional view taken along line A-A' of Fig. 1.

Hereinafter, the case will be described in detail with reference to the accompanying drawings. Embodiments of the ceramic cylindrical target and the cylindrical sputtering target are shown. Further, the present invention is not limited to the embodiments shown below.

Fig. 1 is a schematic view showing a schematic configuration of a cylindrical sputtering target, and Fig. 2 is a cross-sectional view taken along line A-A' of Fig. 1. In addition, for the sake of easy understanding, the first and second drawings show a three-dimensional orthogonal coordinate system including a Z-axis in a vertical direction in a vertical direction and a negative direction in a vertical direction.

As shown in FIG. 1 and FIG. 2, a cylindrical sputtering target (hereinafter referred to as a "cylindrical target") 1 includes a ceramic cylindrical target (hereinafter referred to as a "cylindrical target"). 2) and support tube 3. The cylindrical target 2 and the support tube 3 are joined by a bonding material 4.

Here, the cylindrical target 2 is made of a ceramic having a cylindrical shape in which the outer peripheral surface 2a and the inner peripheral surface 2b of the cross section are concentrically formed, and the end faces 2c1 and 2c2 at both ends in the predetermined longitudinal direction. The ceramics constituting the cylindrical target 2 include, for example, an oxide of at least one of In, Zn, Al, Ga, Zr, Ti, Sn, Mg, and Si. Specifically, the content of Sn is ITO (In ₂ O ₃ -SnO ₂ ) in an amount of 1 to 10% by mass in terms of SnO ₂ , and the content of In is 10 to 60% by mass in terms of In ₂ O ₃ , and Ga is used. The content is 10 to 60% by mass in terms of Ga ₂ O ₃ , the content of Zn is 10 to 60% by mass of IGZO (In ₂ O ₃ -Ga ₂ O ₃ -ZnO), and the content of Al is Al ₂ O _{3 .} In the case of IZO (In ₂ O ₃ -ZnO) in which the content of AZO (Al ₂ O ₃ -ZnO) and Zn is 0.1 to 15% by mass in terms of ZnO, it is not limited thereto. Further, the end faces 2c1 and 2c2 are collectively referred to as both end faces 2c.

Further, the support tube 3 is insertably formed in a cylindrical target The cylindrical member of the hollow portion of 2 is also referred to as the substrate of the cylindrical target 1. The material of the support tube 3 can be suitably selected for use by a user of the prior art. For example, stainless steel, titanium, titanium alloy, or the like can be applied as the support tube 3, but is not limited thereto.

Further, the bonding material 4 bonds the inner circumferential surface 2b of the cylindrical target 2 to the outer circumferential surface 3a of the support tube 3. Such a bonding material 4 can be suitably selected and used by a user. For example, indium, indium-tin alloy, or the like can be used as the bonding material 4, but is not limited thereto.

The flat type target used in the conventional flat type magnetron sputtering apparatus is low in use efficiency, and the target remaining after use is about one-half of the thickness of the target before use, so that the strength of the target is lowered. The risk of cracking is low. Therefore, in the flat type target, the crack in the sputtering is rarely considered, and in particular, the surface shape of the joint surface with respect to the substrate called the support plate is not considered. Similarly, the surface shape of the inner peripheral surface 2b side has not been considered in the cylindrical target until now.

On the other hand, in the cylindrical target 1 configured as shown in Fig. 1 and Fig. 2, the outer peripheral surface 2a of the cylindrical target 2 is a sputtering surface, and the cylindrical target 2 is The outer peripheral surface 2a side is sequentially consumed by sputtering. The cylindrical target 2 used in the cylindrical target 1 is more efficient to use than the above-described flat type target, and the thickness of the cylindrical target 2 is from the outer peripheral surface 2a side as a whole. The ground is thin. At this time, even if the inner peripheral surface 2b of the cylindrical target 2 continues to be sputtered, it is not consumed and remains until the end.

As described above, the cylindrical target 1 is subjected to thermal expansion of the support tube 3 to impart a radial direction force to the cylindrical target 2. Therefore, in sputtering The cylindrical target 2 in the final thinning stage of the thinning is more likely to be cracked than the cylindrical target 2 before sputtering. On the other hand, by appropriately controlling the surface shape of the inner peripheral surface 2b side of the cylindrical target 2 which has not been considered so far, it is particularly remarkable to maintain the cylindrical target at the end of the sputtering which is thinned during sputtering. The mechanical strength of the material 2 is such as to inhibit the occurrence of cracks. The cylindrical target 2 according to the embodiment will be further described below.

The cylindrical surface target 2 of the embodiment has a surface roughness Ra of 1.2 μm or less, preferably 1.0 μm or less, more preferably 0.8 μm or less, and still more preferably 0.5 μm or less. When the surface roughness Ra of the inner peripheral surface 2b exceeds 1.2 μm, for example, when the cylindrical target 2 is thinned by long-term sputtering due to the application rate of 80% or more, cracking is likely to occur. Further, it is preferable that the surface roughness Ra of the crack-based inner peripheral surface 2b due to the surface shape of the inner peripheral surface 2b is lower, but the surface roughness Ra of the inner peripheral surface 2b is lower, and the inner peripheral surface 2b and the joint material are lower. The worse the wetness of 4 is. When the inner peripheral surface 2b and the bonding material 4 are inferior in wettability, after the cylindrical target 2 is joined to the support tube 3, peeling easily occurs between the inner peripheral surface 2b and the bonding material 4. When peeling occurs between the inner peripheral surface 2b and the bonding material 4, the portion after peeling during sputtering cannot be sufficiently cooled, and the cylindrical target 2 is easily cracked. In view of such a situation, the surface roughness Ra of the inner peripheral surface 2b is preferably 0.05 μm or more, more preferably 0.1 μm or more, more preferably 0.15 μm or more, and particularly preferably 0.2 μm or more.

Here, the surface roughness Ra corresponds to the value of "arithmetic average roughness Ra" of JIS B0601:2013. Further, the surface roughness Ra can be changed in the surface processing of the inner peripheral surface 2b by changing the commonly used grinding Stone number or processing speed to control.

Moreover, the surface roughness Ra of the outer peripheral surface 2a of the cylindrical target 2 is preferably 1.5 μm or less, more preferably 1.0 μm or less, and most preferably 0.5 μm or less. When the surface roughness Ra of the outer peripheral surface 2a exceeds 1.5 μm, the occurrence of small nodule at the initial stage of sputtering or cracking during joining of the support tube 3 may be affected. However, as described above, the outer peripheral surface 2a of the cylindrical target 2 is sequentially consumed by sputtering, so that the influence on the crack of the cylindrical target 2 is extremely small except for the initial stage of use. Further, the minimum value of the surface roughness Ra of the outer peripheral surface 2a is not particularly limited, but the efficiency of the processing operation is preferably 0.05 μm or more.

Further, the surface roughness Ra of both end faces 2c of the cylindrical target 2 is preferably 1.4 μm or less, more preferably 1.2 μm, still more preferably 1.0 μm or less. When the surface roughness Ra of the both end faces 2c of the cylindrical target 2 is 1.4 μm or less, cracking of the cylindrical target 2 due to, for example, thermal expansion at the time of sputtering can be prevented or suppressed. Moreover, the particles and arc generated during sputtering are lowered, and a good film quality can be obtained. Further, the minimum value of the surface roughness Ra of the both end faces 2c of the cylindrical target 2 is not particularly limited, but the efficiency of the working operation is preferably 0.05 μm or more.

Further, the relative density of the cylindrical target 2 is preferably 95% or more, more preferably 98% or more, still more preferably 99% or more. When the relative density of the cylindrical target 2 is 95% or more, cracking of the cylindrical target 2 due to, for example, thermal expansion at the time of sputtering can be prevented or suppressed. Moreover, the particles and arc generated during sputtering are lowered, and a good film quality can be obtained. Here, the method of measuring the relative density of the cylindrical target 2 will be described below.

The relative density of the cylindrical target 2 was determined in accordance with the Archimedes method. Specifically, the air weight of the cylindrical target 2 is divided by the volume (=the weight of the water of the cylindrical target 2 / the specific gravity of the water in the measured temperature) with respect to the theoretical density according to the following formula (X) The value of the percentage of ρ (g/cm ³ ) is set as the relative density (unit: %).

In the above formula (X), C ₁ to C _i represent the content (% by mass) of the constituent materials constituting the cylindrical target 2, respectively, and ρ ₁ to ρ _i represent the constituent materials corresponding to C ₁ to C _i . Density (g/cm ³ ).

Further, the cylindrical target 2 preferably has an eccentricity of 0.2 mm or less, more preferably 0.1 mm or less, and still more preferably 0.05 mm or less. If the eccentricity exceeds 0.2 mm, as described above, the tendency of the thermal expansion of the supported tube 3 to uniformly apply a force in the radial direction to the cylindrical target 2 becomes large, and even if the surface roughness Ra of the inner peripheral surface 2b is very small, it is easy. Cracks are produced. Further, the thickness of the cylindrical target 2 remaining due to the consumption due to sputtering is uneven, and the use efficiency of the cylindrical target 2 may be lowered. Here, the "eccentricity of the inner and outer diameters" is the width of the center point of the outer diameter of the cylindrical target 2 and the center point of the inner diameter.

Further, in the cylindrical target 1 of the embodiment, the bonding ratio between the cylindrical target 2 and the bonding material 4 is preferably 98% or more, more preferably 98.5% or more, still more preferably 99% or more, and particularly preferably 99.5. %the above. If the bonding ratio is less than 98%, the cooling of the unjoined portion is not sufficiently performed, even if the inner peripheral surface The surface roughness Ra of 2b is very small, and the cylindrical target 2 is easily cracked. Here, the "joining ratio" is a ratio of the area of the bonding material 4 to the inner peripheral surface 2b of the cylindrical target 2 with respect to the area of the inner peripheral surface 2b of the cylindrical target 2. This bonding ratio can be obtained by measuring the area of the image obtained by the ultrasonic flaw detection test or the X-ray inspection using an image analysis software. Further, from the viewpoint of accuracy and easiness of measurement, ultrasonic flaw detection is preferred. On the other hand, in the X-ray inspection, the curved film is inserted into the support tube 3 to be inspected, so that the area cannot be accurately measured, or the peeling of the cylindrical target 2 and the bonding material 4 is not easily detected. Bad situation.

In the above, an example in which the cylindrical target 1 is joined to one cylindrical target 2 on the outer side of one support tube 3 is described, but the invention is not limited thereto. For example, two or more cylindrical targets 2 may be arranged on the same axis on the outer side of one or two or more support tubes 3, and the joint may be used as the cylindrical target 1.

Next, an example of a method of manufacturing the cylindrical target 2 will be described. The cylindrical target 2 is produced by granulating a slurry containing a ceramic raw material powder and an organic additive, granulating a granule, and forming a cylindrical shaped body to form a cylindrical shaped body. The firing step of firing the shaped body to produce a fired body. Further, the method of producing the fired body is not limited to the above, and may be any method.

The fired body obtained in the above-described firing step is produced to be longer and thicker than the size of the cylindrical target 2 previously designed. Further, the longitudinal direction of the fired body is, for example, cut or cut, and the outer diameter and the inner diameter are, for example, ground to be individually designed. The way is processed.

The method of polishing the outer peripheral surface 2a side and the inner peripheral surface 2b side of the fired body of the cylindrical target 2 is two types of methods of traverse direction polishing and plunger direction polishing. In the traverse direction polishing system, the grinding is performed while moving the grindstone in a direction parallel to the cylindrical axis of the fired body. The plunger direction polishing system is a method of polishing without moving the movement of the grindstone in the direction of the cutting direction.

In the polishing apparatus for polishing the fired body, the horizontal axis cylindrical grinding disk is processed while the cylindrical shaft of the fired body is rotated in the lateral direction, and the cylindrical shaft of the fired body is erected and rotated. Any of two types of vertical axis cylindrical grinding discs can be used. Further, when the inner peripheral surface 2b side is machined, it is preferable to use a vertical axis cylindrical polishing disk because it is less susceptible to gravity and has a surface roughness Ra or an increase in processing accuracy. In particular, when the inner circumferential surface 2b side of the fired body is processed over a length of 500 mm, the vertical axis cylindrical grinding disk is used, and it is advantageous to reduce the surface roughness Ra relatively easily. However, a horizontal axis cylindrical grinding disc may be used for the processing on the inner peripheral surface 2b side, or a polishing apparatus other than the cylindrical grinding disc may be used.

Finally, the steps related to the end face processing are explained. The end face processing step is a step of processing the end face to produce a cylindrical target 2 of a specific length. The processing of the end faces may be, for example, a person formed by cutting, or may be formed by cutting or grinding. Further, cutting, cutting, and grinding may be combined, and the processing method is not limited.

As described above, the cylindrical target 2 and the cylindrical target 1 of the embodiment can further suppress the occurrence of cracks during sputtering.

[Examples]

[Example 1]

Formulated determined the BET (Brunauer-Emmett-Teller) specific surface area (BET specific surface area) is 5m ² / g of SnO ₂ powder was 10 mass%, and a BET specific surface area of 5m ² / g of In ₂ O ₃ powder of 90 The mass% was mixed in a pot mill by zirconia pellets in a pot to prepare a raw material powder.

In this tank, 0.3% by mass of polyvinyl alcohol, 0.2% by mass of ammonium polycarboxylate, 0.5% by mass of polyethylene glycol, and 50% by mass of water are added to 100% by mass of the raw material powder to carry out a ball mill. The slurry was prepared by mixing. Then, this slurry was supplied to a spray drying apparatus, and spray-drying was carried out under the conditions of a sprayer rotation number of 14,000 rpm, an inlet temperature of 200 ° C, and an outlet temperature of 80 ° C to prepare granules.

The granules were placed in a cylindrical urethane rubber mold having an inner diameter of 220 mm (thickness: 10 mm) and a length of 450 mm having a cylindrical neutron (mandrel) having an outer diameter of 157 mm, and the rubber mold was sealed. CIP (Cold Isostatic Pressing) molding was carried out at a pressure of 800 kgf/cm ^{2 to} prepare a cylindrical molded body.

This molded body was heated at 600 ° C for 10 hours to remove organic components. The heating rate was set to 50 ° C / h. Further, the heated molded body is fired to prepare a fired body. The firing was carried out under an oxygen atmosphere at a firing temperature of 1550 ° C, a firing time of 12 hours, and a temperature increase rate of 300 ° C / h. Further, the cooling rate was performed by setting 1550 ° C to 800 ° C to 50 ° C / h and 800 ° C or lower to 30 ° C / h. The resulting fired body had a relative density of 99.8%.

Next, the grinding machine is polished using a horizontal axis cylindrical grinding disc. Get the body. First, the outer peripheral surface 2a side was machined by using the grinding direction of the #170 grindstone until the outer diameter of the fired body became 153.2 mm, and the inner peripheral surface 2b was processed by the direction grinding using the #170 grindstone. The side until the inner diameter of the fired body became 134.8 mm.

Then, the inner peripheral surface 2b side of the fired body is processed by the traverse direction grinding. The grindstone is made of vitrified as a binder and has an abrasive grain size of #600. The cut amount per millstone is 0.003 mm, and the moving speed of the grindstone in the cylinder axis direction is 300 mm/ Min, the rotating body was rotated at a speed of 70 rpm.

The above-described traverse direction was repeated once in one pass, and the inside of the fired body was repeated until the inner diameter of the fired body was 135 mm, and the spark out was moved in the cylinder axis direction by the cut amount of 0. (ie, 1 round trip).

Next, the processing of the outer peripheral surface 2a side of the fired body is performed. For the grindstone, a glazing compound was used as the binder and the abrasive grain size was #600. The cutting amount per grindstone is 0.002 mm, the moving speed of the grindstone in the cylinder axis direction is 150 mm/min, and the rotational speed of the fired body is 20 rpm, and the processing is repeated one pass in one pass until the outer diameter becomes After 153 mm, two times of spark discharge was performed. Finally, both ends of the fired body were cut and the length was processed to 300 mm, and a cylindrical target 2 having an outer diameter of 153 mm, an inner diameter of 135 mm, and a length of 300 mm was produced.

In the above-mentioned cylindrical target 2, the support tube 3 made of titanium having an outer diameter of 133 mm, an inner diameter of 123 mm, and a length of 1500 mm was bonded to each other using In solder as the bonding material 4, and three cylindrical targets 2 were joined. Three sets of cylindrical targets 1 were made. The interval between the cylindrical targets 2 (the length of the divided portion) is set to 0.5 mm. Moreover, the undercoat of In solder was applied to the inner peripheral surface 2b of the cylindrical target 2 before ultrasonic welding using ultrasonic solder.

[Embodiment 2]

Formulation BET specific surface area of 4m ² / ZnO powder g of 44.2% by mass, BET specific surface area of 7m ² / g of In ₂ O ₃ powder of 25.9 mass%, and a BET specific surface area ₂ O ₃ powder was 10m ² / g of Ga 29.9 The mass% was mixed in a tank by a zirconia pellet in a tank to prepare a raw material powder.

In this tank, 0.3% by mass of polyvinyl alcohol, 0.4% by mass of ammonium polycarboxylate, 1.0% by mass of polyethylene glycol, and 50% by mass of water are added to 100% by mass of the raw material powder to carry out a ball mill. Mix and prepare into a raw material powder.

Then, the preparation of the granules, the production of the molded body, and the removal of the organic component derived from the molded body were carried out in the same manner as in Example 1. Further, the molded body was fired at a firing temperature of 1400 ° C, a firing time of 10 hours, a temperature increase rate of 300 ° C / h, and a temperature drop rate of 50 ° C / h to prepare a fired body. The relative density of the obtained fired body was 99.7%.

Further, in the same manner as in the first embodiment, the obtained fired body was polished, and the cylindrical target 2 obtained by cutting and the cylindrical target 2 were joined to the support tube 3 to prepare a cylindrical target 1. .

[Example 3]

Formulation BET specific surface area of 4m ² / g of ZnO powder of 95 mass%, BET specific surface area of 5m ² / g of Al ₂ O ₃ powder of 5 mass%, in the tank for ball mill by zirconia pellets to prepare ceramic raw material powder .

In this tank, 0.3% by mass of polyvinyl alcohol, 0.4% by mass of ammonium polycarboxylate, 1.0% by mass of polyethylene glycol, and 50% by mass of water are added to 100% by mass of the raw material powder, respectively. The ball mill was mixed to prepare a slurry.

Then, in the same manner as in Example 1, the preparation of the granules, the production of the molded body, and the removal of the organic component derived from the molded body were carried out. Further, the molded body was fired at a firing temperature of 1400 ° C, a firing time of 10 hours, a temperature increase rate of 300 ° C / h, and a temperature drop rate of 50 ° C / h to prepare a fired body. The obtained fired body had a density of 99.9%.

Further, in the same manner as in the first embodiment, the obtained fired body is polished, and the cylindrical target 2 obtained by cutting and the cylindrical target 2 are joined to the support tube 3 to produce a cylindrical target. 1.

[Example 4]

A sintered body (ITO) obtained in the same manner as in Example 1 was processed using a horizontal-axis cylindrical grinding disc, and a cylindrical target 2 having an outer diameter of 153 mm, an inner diameter of 135 mm, and a length of 300 mm was produced. First, the outer peripheral surface 2a side was processed by using the grinding direction of the #170 grindstone until the outer diameter of the fired body became 153.2 mm, and the inner circumference was processed by the plunger direction grinding using the #170 grindstone. The inner surface of the surface 2b was up to 134.8 mm from the inner diameter of the fired body.

Then, the inner peripheral surface 2b side of the fired body is processed by the traverse direction grinding. In the grindstone system, the glazing compound is used as the binder and the abrasive grain size is #1000. The cutting amount per millstone is 0.002 mm, the moving speed of the grindstone in the cylinder axis direction is 300 mm/min, and the fired body is used. The rotation was performed at a rotation speed of 70 rpm.

The above-described traverse direction polishing was repeated one pass in one pass until the inner diameter of the fired body was 135 mm, and then the spark discharge was performed twice.

Then, the processing on the outer peripheral surface 2a side of the fired body is performed. In the grindstone system, the glazing compound is used as the binder and the abrasive grain size is #600. The cutting amount per grindstone is 0.002 mm, the moving speed of the grindstone in the cylinder axis direction is 150 mm/min, and the fired body is used. The rotation speed was 20 rpm, and the machining was repeated one pass in one pass until the outer diameter became 153 mm, and then the spark discharge was performed twice. Finally, the length of both ends of the fired body was cut to 300 mm, and a cylindrical target 2 having an outer diameter of 153 mm, an inner diameter of 135 mm, and a length of 300 mm was produced.

Further, in the same manner as in the first embodiment, the cylindrical target 2 and the support tube 3 were joined to each other to form a cylindrical target 1.

[Example 5]

A cylindrical target 2 and a cylindrical target 1 were produced in the same manner as in Example 4 except that the fired body (IGZO) obtained in the same manner as in Example 2 was used.

[Embodiment 6]

A cylindrical target 2 and a cylindrical target 1 were produced in the same manner as in Example 4 except that the fired body (AZO) obtained in the same manner as in Example 3 was used.

[Embodiment 7]

The obtained fired body (ITO) was processed in the same manner as in Example 1 to produce a cylindrical target 2 having an outer diameter of 153 mm, an inner diameter of 135 mm, and a length of 300 mm. The horizontal axis cylindrical grinding disc is used for the processing on the outer peripheral surface 2a side, and the vertical axis cylindrical grinding disc is used for the processing on the inner peripheral surface 2b side.

First, the outer peripheral surface 2a side was machined by using the grinding direction of the #170 grindstone until the outer diameter of the fired body became 153.2 mm, and the inner peripheral surface 2b was processed by the direction grinding using the #170 grindstone. The side until the inner diameter of the fired body became 134.8 mm.

Then, the inner peripheral surface 2b side of the fired body is processed by the traverse direction grinding. For the grindstone, the glazing compound is used as the binder and the abrasive grain size is #600. The cutting amount per millstone is 0.003 mm, and the moving speed of the grindstone in the cylinder axis direction is 300 mm/min. The body was rotated at a rotation speed of 70 rpm.

The above-described traverse direction was repeated once in one pass and then repeated until the inner diameter of the fired body was 135 mm, and then two-times of spark scattering was performed.

Next, the processing of the outer peripheral surface 2a side of the fired body is performed. For the grindstone, a glazing compound was used as the binder and the abrasive grain size was #600. The cutting amount per grindstone is 0.002 mm, the moving speed of the grindstone in the cylinder axis direction is 150 mm/min, and the rotational speed of the fired body is 20 rpm, and the processing is repeated one pass in one pass until the outer diameter becomes After 153 mm, two times of spark discharge was performed. Finally, both ends of the fired body were cut and the length was processed to 300 mm, and a cylindrical target 2 having an outer diameter of 153 mm, an inner diameter of 135 mm, and a length of 300 mm was produced.

Further, in the same manner as in the first embodiment, the cylindrical target 2 and the support tube 3 were joined to each other to form a cylindrical target 1.

[Embodiment 8]

A cylindrical target 2 and a cylindrical target 1 were produced in the same manner as in Example 7 except that the fired body (IGZO) obtained in the same manner as in Example 2 was used.

[Embodiment 9]

A cylindrical target 2 and a cylindrical target 1 were produced in the same manner as in Example 7 except that the fired body (AZO) obtained in the same manner as in Example 2 was used.

[Embodiment 10]

The cylindrical target 2 and the cylindrical target 1 were produced in the same manner as in Example 1 except that the abrasive grain size of the grindstone on the inner peripheral surface 2b side of the polished body (ITO) was changed to #320.

[Example 11]

A cylindrical target 2 and a cylindrical target 1 were produced in the same manner as in Example 2, except that the abrasive grain size of the grindstone on the inner peripheral surface 2b side of the ground fired body (IGZO) was set to #320. .

[Embodiment 12]

A cylindrical target 2 and a cylindrical target 1 were produced in the same manner as in Example 3 except that the abrasive grain size of the grindstone on the inner peripheral surface 2b side of the abrasive-fired body (AZO) was changed to #320. .

[Example 13]

A cylindrical target 2 and a cylindrical target 1 were produced in the same manner as in Example 1 except that the abrasive grain size of the grindstone on the inner peripheral surface 2b side of the polished body (ITO) was set to #170. .

[Embodiment 14]

A cylindrical target 2 and a cylindrical target 1 were produced in the same manner as in Example 2 except that the abrasive grain size of the grindstone on the inner peripheral surface 2b side of the IGZO was set to #170. .

[Example 15]

A cylindrical target 2 and a cylindrical target 1 were produced in the same manner as in Example 3 except that the abrasive grain size of the grindstone on the inner peripheral surface 2b side of the fired fired body (AZO) was changed to #170. .

[Example 16]

A cylindrical target 2 and a cylindrical target 1 were produced in the same manner as in Example 1 except that the abrasive grain size of the grindstone on the inner peripheral surface 2b side of the polished body (ITO) was set to #1500. .

[Example 17]

A cylindrical target 2 and a cylindrical target 1 were produced in the same manner as in Example 2 except that the abrasive grain size of the grindstone on the inner peripheral surface 2b side of the IGZO was set to #1500. .

[Embodiment 18]

A cylindrical target 2 and a cylindrical target 1 were produced in the same manner as in Example 3 except that the abrasive grain size of the grindstone on the inner peripheral surface 2b side of the abrasive-fired body (AZO) was set to #1500. .

[Comparative Example 1]

A cylindrical target 2 having an outer diameter of 153 mm, an inner diameter of 135 mm, and a length of 300 mm was produced by using a horizontal axis cylindrical grinding disc to process a fired body (ITO) obtained in the same manner as in the first embodiment. First, by using the #170 millstone column Grinding in the plug direction, after processing the outer diameter up to 153.2 mm, the inner diameter was processed to 134.8 mm by grinding in the direction of the plunger of #石.

Then, the inner peripheral surface 2b side of the fired body is processed by the traverse direction grinding. In the grindstone system, the glazing compound is used as the binder and the abrasive grain size is #80, the cutting amount per mill pass is 0.005 mm, and the moving speed of the grindstone in the cylinder axis direction is 300 mm/min. The fired body was ground at a rotation speed of 70 rpm.

The above-described traverse direction grinding was repeated one pass in one pass until the inner diameter of the fired body became 135 mm, and then two-stage spark discharge was performed.

Next, the processing of the outer peripheral surface 2a side of the fired body is performed. For the grindstone, a glazing compound was used as the binder and the abrasive grain size was #600. The cutting amount per grindstone is 0.002 mm, the moving speed of the grindstone in the direction of the cylinder axis is 150 mm/min, and the rotational speed of the fired body is 20 rpm, and the machining is repeated one pass in one pass to the outer diameter. After 153 mm, the spark discharge was performed twice. Finally, both ends of the fired body were cut and the length was processed to 300 mm, and a cylindrical target 2 having an outer diameter of 153 mm, an inner diameter of 135 mm, and a length of 300 mm was produced.

Further, in the same manner as in the first embodiment, the cylindrical target 2 and the support tube 3 were joined to each other to produce a cylindrical target 1.

[Comparative Example 2]

The cylindrical target 2 and the cylindrical target 1 were produced in the same manner as in Comparative Example 1, except that the fired body (IGZO) obtained in the same manner as in Example 2 was used.

[Comparative Example 3]

The cylindrical target 2 and the cylindrical target 1 were produced in the same manner as in Comparative Example 1, except that the fired body (AZO) obtained in the same manner as in Example 3 was used.

The bonded cylindrical target 1 produced in each of Examples 1 to 3 was visually observed, and no crack was observed in all of them. Next, sputtering of three sets of cylindrical targets 1 in which three cylindrical targets 2 are joined to the support tube 3 is performed, and after using the cylindrical target 2 to a usage rate of 80% (mass basis), visual observation is performed. The cylindrical target 2 was confirmed to have cracks. The conditions of the sputtering were substrate temperature: 100 ° C, sputtering pressure: 0.2 Pa, power: 20 KW, and number of target rotations: 10 rpm.

The results obtained by Example 1 to Comparative Example 3 are shown in Tables 1 to 3. Further, in the cylindrical target 2, ITO is shown in Table 1, IGZO is used in Table 2, and AZO is shown in Table 3. In each of the tables, the surface roughness Ra of the outer peripheral surface 2a and the inner peripheral surface 2b, the eccentricity of the cylindrical target 2, and the numerical value of the bonding ratio between the cylindrical target 2 and the bonding material 4 are shown in each table. Among the measured values of the cylindrical target 2, the minimum value and the maximum value are shown. Here, the definition of each value in the cylindrical target 2 is shown below.

[Measurement of surface roughness Ra of inner peripheral surface, outer peripheral surface, and both end faces]

The surface roughness Ra of the outer peripheral surface 2a, the inner peripheral surface 2b, and the both end surfaces 2c of the cylindrical target 2 was measured using the surface roughness measuring device (Surf Coder SE1700 / manufactured by Otaru Laboratory Co., Ltd.). Outer peripheral surface 2a and inner peripheral surface 2b The measurement is in the vicinity of the end faces 2c (i.e., the end faces 2c1, 2c2) of the cylindrical target 2, and the circumferential directions are approximately four at equal intervals (that is, the outer peripheral surface 2a and the inner peripheral surface 2b are 8 places). ). In the measurement of the both end faces 2c, the end faces 2c (i.e., the end faces 2c1, 2c2) of the cylindrical target 2 are respectively provided at four intervals (i.e., eight places) at equal intervals in the circumferential direction. Among the measured surface roughness Ra of the eight points, the maximum value was set to the value of the surface roughness Ra of the cylindrical target 2 on each surface. In addition, in the examples and the comparative examples, the surface roughness Ra of both end faces 2c of the cylindrical target 2 is 1.4 μm or less.

[Measurement of eccentricity]

The thickness of the end portion of the cylindrical target 2 was arbitrarily measured by a vernier scale, and the difference between the thickness (maximum thickness) at the thickest point and the gauge thickness (9.00 mm) was measured as an eccentricity. For example, when the maximum thickness is 9.10 mm, the value of the eccentricity is 0.10 mm.

[Measurement of bonding rate]

The ultrasonic flaw detection apparatus (manufactured by SDS-WIN 24235T/KJTD Co., Ltd.) was used to inspect the joined state of the inner peripheral surface 2b of the cylindrical target 2 and the bonding material 4 at a pitch of 0.5 mm. From the image obtained, the area of the inner peripheral surface 2b of the cylindrical target 2 and the bonding material 4 was measured by using an image analysis software (particle analysis Ver. 3, manufactured by Tiejinjin Technology Co., Ltd.), and the calculation was performed. The value of the joint ratio is set as the ratio of the area of the inner peripheral surface 2b.

Further effects or modifications can be readily derived by those of ordinary skill in the art. Therefore, the broader aspects of the invention are not limited to the specific details and A representative embodiment. Therefore, various modifications may be made without departing from the spirit and scope of the inventions.

2‧‧‧Ceramic cylindrical target (cylindrical target)

2a‧‧‧outer surface

2b‧‧‧ inner circumference

3‧‧‧Support tube

3a‧‧‧ outer perimeter

4‧‧‧Material

Claims (13)

A ceramic cylindrical target having a surface roughness Ra of an inner circumferential surface of 1.2 μm or less. A ceramic cylindrical target having a surface roughness Ra of an inner circumferential surface of 1.0 μm or less. A ceramic cylindrical target having a surface roughness Ra of an inner circumferential surface of 0.8 μm or less. A ceramic cylindrical target having a surface roughness Ra of 0.5 μm or less on the inner peripheral surface thereof. The ceramic cylindrical target according to any one of claims 1 to 4, wherein the surface roughness Ra is 0.1 μm or more. The ceramic cylindrical target according to any one of claims 1 to 4, which contains one or more of In, Zn, Al, Ga, Zr, Ti, Sn, Mg, and Si. The ceramic cylindrical target according to any one of claims 1 to 4, wherein the content of Sn is 1 to 10% by mass of ITO in terms of SnO ₂ . The ceramic cylindrical target according to any one of claims 1 to 4, wherein the content of In is 10 to 60% by mass in terms of In ₂ O ₃ , and the content of Ga is converted in terms of Ga ₂ O ₃ It is 10 to 60% by mass, and the content of Zn is 10 to 60% by mass of IGZO in terms of ZnO. The ceramic cylindrical target according to any one of claims 1 to 4, wherein the content of Al is 0.1 to 5% by mass of AZO in terms of Al ₂ O ₃ . The ceramic cylindrical target according to any one of claims 1 to 4, wherein the content of Zn is 1 to 15% by mass of IZO in terms of ZnO. The ceramic cylindrical target according to any one of claims 1 to 4, wherein the eccentricity of the inner and outer diameters is 0.2 mm or less. A cylindrical sputtering target, comprising: the ceramic cylindrical target according to any one of claims 1 to 4; and a cylindrical substrate inserted through the ceramic The hollow portion of the cylindrical target is joined to the inner circumferential surface of the ceramic cylindrical target via a bonding material. The cylindrical sputtering target according to claim 12, wherein a bonding ratio of the ceramic cylindrical target to the bonding material is 98% or more.