TWI635194B - Cylindrical sputtering target and manufacturing method thereof - Google Patents

Abstract

An object of the present invention is to provide a cylindrical sintered body having a length in the direction of a cylindrical axis of 470 mm or more, a cylindrical sputtering target, and a method for manufacturing the same. According to a method for manufacturing a cylindrical sputtering target having a cylindrical sintered body according to an embodiment of the present invention, a cylindrical forming body is arranged on a work table, and the length of the cylindrical forming body in the direction of the cylindrical axis is Above 600 mm, the table is provided with an oxygen element supply port. The oxygen element supply port is connected to a pipeline for supplying oxygen element. The oxygen element supply port supplies and sinters the oxygen element in the direction of the cylinder axis. The oxygen element supply port It is smaller than the inner circumference of the cylinder provided inside the cylinder of the cylindrical forming body. Moreover, in other aspects, the workbench can also be arranged in the chamber, and the pipeline for supplying oxygen element can also be connected to the oxygen element supply port from outside the chamber.

Description

Cylindrical sputtering target and manufacturing method thereof

The invention relates to a cylindrical sputtering target and a manufacturing method thereof. The present invention particularly relates to a method for manufacturing a cylindrical sintered body constituting a cylindrical sputtering target.

In recent years, the manufacturing technology of flat panel displays (FPDs) or solar cells has developed rapidly, and is progressing toward large-scale. And with the market expansion of these products, the demand for large glass substrates has increased.

In particular, in a sputtering device for forming a metal thin film or an oxidized metal thin film on a large glass substrate, a cylindrical (also called a rotating or rotating) sputtering target is used instead of a conventional flat plate sputtering target. Pieces. Compared with the flat-shaped sputtering target, the cylindrical sputtering target has the advantages of high target use efficiency, less erosion, and less particles due to peeling of the deposit.

The cylindrical sputtering target used in the sputtering device for forming a thin film on a large glass substrate as described above needs to have a length of more than 3000 mm. Technically, it is not possible to achieve integral molding manufacturing and grinding of cylindrical sputtering targets of such a length. Therefore, a divided sputtering target is usually formed by connecting a plurality of cylindrical sintered bodies of several tens mm to several hundreds mm.

Here, not only the above-mentioned cylindrical sintered body, but also the connection of the general sintered body is required to improve the mechanical strength and the quality of the film using the sintered body. When a plurality of sintered bodies are bonded to a substrate, the sintered bodies are arranged at a constant interval from each other. When the sintered bodies are arranged without gaps and joined to the substrate, the sintered bodies expand and contract due to the heat during sputtering, so the sintered bodies may collide with each other to cause cracking or chipping. On the other hand, there is no gap between the sintered bodies in the sintered body that should be subjected to sputtering. Therefore, there is a problem that the constituent materials of the substrate are subjected to sputtering or the like, and there is a problem that a thin film having a desired composition cannot be formed. Furthermore, in a split sputtering target that connects multiple sintered bodies, the relative density difference between adjacent sintered bodies (that is, the "solid-to-solid deviation" in the density of the sintered body) will affect the film using this split sputtering target Quality. In this way, the shorter the connected sintered body, the more the sputtering target will be divided, and the higher the risk of affecting the sputtering characteristics.

In order to avoid at least the foregoing problems, a manufacturing technique for manufacturing a cylindrical sintered body as long as possible corresponding to fewer divided sputtering targets is required. The problems in manufacturing long-sized cylindrical sintered bodies are the relative density difference within the sintered body (ie, the "internal solid deviation" of the density of the sintered body) and the mechanical strength. For example, Patent Document 1 (Patent Document 1: Japanese Patent Publication No. H8-144056) discloses that during the sintering of an ITO target, the concentration of oxygen in the gas environment greatly affects the stability (density and strength) of the target quality. Generally, a sintering furnace used for ITO supplies oxygen from the furnace wall side.

However, in the case of a long-sized cylindrical sintered body, the gas convection in the cylinder during sintering is insufficient, and the oxygen element in the cylinder may be insufficient. An object of the present invention is to provide a cylindrical sintering having a length of 470 mm or more in the direction of the cylindrical axis in order to correspond to a divided sputtering target obtained by joining a plurality of sintered bodies to a substrate with less division. The object is a body, a cylindrical sputtering target, and a manufacturing method thereof. In addition, it is an object of the present invention to provide a cylindrical sintered body, a cylindrical sputtering target, and a method for manufacturing the same, which have high homogeneity within and among solids.

According to a manufacturing method of a cylindrical sputtering target according to an embodiment of the present invention, in the manufacturing method of a cylindrical sputtering target having a cylindrical sintered body, a cylindrical forming type is arranged on a table. The length of the cylinder-shaped body in the direction of the cylinder axis is 600 mm or more. The table is provided with an oxygen element supply port. The oxygen element supply port is connected to a pipeline for supplying oxygen element. The oxygen element is supplied in the direction of the cylinder axis and sintered. The oxygen element supply port is smaller than the inner circumference of the cylinder provided on the inside of the cylinder of the cylinder forming body.

In addition, in other aspects, the workbench can also be arranged in the chamber, and the pipeline for supplying oxygen element can also be connected to the oxygen element supply port from outside the chamber.

In addition, in other aspects, an oxygen element may be supplied to the hollow portion inside the cylinder of the cylindrical forming body and sintered.

In addition, in other aspects, an oxygen element may be supplied from below the cylinder axis direction of the cylinder forming body toward upward and sintered.

The cylindrical sintered body used in the cylindrical sputtering target according to an embodiment of the present invention is a cylindrical sintered body having a length of 470 mm or more in the direction of the cylindrical axis and is in the direction of the cylindrical axis. The relative density difference is within 0.1%.

The cylindrical sintered body used in the cylindrical sputtering target according to an embodiment of the present invention is a cylindrical sintered body having a length of 470 mm or more in the direction of the cylindrical axis, and is on the inner side of the cylinder. The equivalent circle diameter of the area of the observed pores was 1 μm or less on average.

The cylindrical sintered body used in the cylindrical sputtering target according to an embodiment of the present invention is a cylindrical sintered body having a length of 470 mm or more in the direction of the cylindrical axis, and is on the inner side of the cylinder. The number of the observed pores is 4.25╳10 ^-5 / μm ² or less on average.

In addition, in other aspects, the hole observed on the inner side of the cylinder may be a hole observed at 1.176 mm ² in each of the independent at least five positions in the central portion in the direction of the cylinder axis.

According to the present invention, it is possible to provide a cylindrical sintered body having a length in the direction of a cylindrical axis of 470 mm or more, a cylindrical sputtering target, and a manufacturing method thereof. In addition, it is also possible to provide a cylindrical sintered body, a cylindrical sputtering target, and a method for manufacturing the same, which have high homogeneity in solids and between individuals.

Hereinafter, a cylindrical sputtering target of the present invention and a method for manufacturing the same will be described with reference to the drawings. However, the cylindrical sputtering target and the method for manufacturing the same according to the present invention can be implemented in a variety of different states, and are not limited to the description content of the implementation modes illustrated below. Moreover, in the drawings referred to in this embodiment, the same parts or parts having the same functions will be marked with the same symbols, and repeated explanations will be omitted.

Embodiments will be described below.

The outline of the structure and structure of the cylindrical sputtering target and cylindrical sintered body concerning embodiment of this invention is demonstrated using FIG.1 and FIG.2.

The outline of the cylindrical sputtering target will be described below.

FIG. 1 is a perspective view showing an example of a cylindrical sintered body included in a cylindrical sputtering target according to an embodiment of the present invention. As shown in FIG. 1, the cylindrical sputtering target 100 has a plurality of cylindrical sintered bodies 110 having a hollow structure. The plurality of cylindrical sintered bodies 110 are arranged adjacent to each other through a certain space. In FIG. 1, for convenience of explanation, the space of the adjacent cylindrical sintered bodies 110 is enlarged. The details of the hollow portion inside the cylinder of the cylindrical sintered body 110 are shown in FIG. 2, and a cylindrical base material 130 for supporting the cylindrical sintered body 110 is introduced.

The thickness of the cylindrical sintered body 110 can be set to 6.0 mm or more and 20.0 mm or less. In addition, the length in the cylindrical axis direction of the cylindrical sintered body 110 can be set to 470 mm or more and 1500 mm or less. The outer diameter of the cylindrical sintered body 110 can be 147 mm or more and 175 mm or less. The inner diameter of the cylindrical sintered body 110 can be set to 135 mm or less. In addition, the space in the cylindrical axis direction between adjacent cylindrical sintered bodies 110 can be set to be 0.1 mm or more and 0.4 mm or less.

The material of the cylindrical sintered body 110 may be, for example, an ITO sintered body (Indium Tin Oxide) made of indium, tin, and oxygen elements, an IZO sintered body (Indium Zinc Oxide) made of indium, zinc, and oxygen elements, IGZO sintered body (Indium Gallium Zinc Oxide) made of indium, gallium, zinc and oxygen elements, AZO sintered body (Aluminum Indium Zinc Oxide) made of zinc, aluminum and oxygen elements, zinc oxide (ZnO), titanium dioxide (TiO2) ₂ ) The sintered body. However, the cylindrical sintered body of the cylindrical sputtering target used in the present invention may be a ceramic sintered body containing an oxygen element, and is not limited to the above composition.

Here, the density of the cylindrical sintered body 110 in this embodiment may also be 99.5% or more. The density of the cylindrical sintered body 110 may be 99.6% or more. In addition, the relative density difference of the cylindrical sintered body 110 in the solid axis direction may be 0.1% or less. The relative density difference of the cylindrical sintered body 110 along the direction of the cylindrical axis may be 0.05% or less, and still more preferably 0.03% or less. In addition, the relative density difference between the adjacent cylindrical sintered bodies 110a and 110b, that is, the relative density difference between the solids of the cylindrical sintered bodies may be 0.1% or less.

The density of the sintered body is expressed as a relative density. The relative density is based on the measured density and theoretical density, and is expressed as relative density = (measured density / theoretical density) ╳ 100 (%). The relative density difference is the difference between the measured density and the theoretical density, and it is expressed as relative density difference = (measured density difference / theoretical density) ╳ 100 (%). The theoretical density is the density value calculated from the theoretical density of the element oxide of the sintered body from which the oxygen element is removed. For example, if it is an ITO target, among the indium, tin, and oxygen elements that belong to each constituent element, indium oxide (In ₂ O ₃ ) and tin oxide (SnO ₂ ) are used as the oxides of indium and tin to remove the oxygen element. To calculate the theoretical density. Among them, the elemental analysis value (at% or mass%) of indium and tin in the sintered body is converted into a mass ratio of indium oxide (In ₂ O ₃ ) and tin oxide (SnO ₂ ). For example, in the case of an ITO target having 90% by mass of indium oxide and 10% by mass of tin oxide, the theoretical density is calculated as (In ₂ O ₃ density (g / cm ³ ) ╳90 + SnO ₂ Calculated as density (g / cm ³ ) ╳10) / 100 (g / cm ³ ). The theoretical density of In ₂ O ₃ was 7.18 g / cm ³ and the theoretical density of SnO ₂ was 6.95 g / cm ^{3. The} theoretical density was calculated to be 7.157 (g / cm ³ ). In addition, if each constituent element contains Zn, it can be calculated using ZnO as an oxide, and if it contains Ga, it can be calculated using Ga ₂ O ₃ as an oxide. Calculated based on the theoretical density of ZnO being 5.67 g / cm ³ and the theoretical density of Ga ₂ O ₃ as 5.95 g / cm ³ . On the other hand, the measured density is the value of weight divided by volume. In the case of a sintered body, the volume can be calculated by Archimedes' method. The cylindrical sintered body 110 can be used to cut out cylindrical measurement samples with a width of 40 to 50 mm every 150 mm along the cylindrical axis direction, and calculate the relative density of each sample to evaluate the cylindrical sintered body. The difference in relative density along the axis of the cylinder in the solid of 110.

As described above, by setting the length and the relative density of the cylindrical sintered body to the above ranges, the mechanical strength of the cylindrical sintered body can be improved, and the occurrence of nodules can be suppressed when using the cylindrical sintered body. Or it can suppress the particles generated by the arc, and can also reduce the impurities of the thin film and increase the density of the film. Furthermore, by setting the relative density difference between the solids and solids of the cylindrical sintered body within the above-mentioned ranges, it is possible to suppress the distortion of the electric field in the divided sputtering target having a plurality of cylindrical sintered bodies. . Therefore, stable discharge characteristics can be obtained during sputtering, and a thin film having extremely high in-plane uniformity can be formed on a large substrate having a size exceeding a single cylindrical sintered body.

The difference in the solids of the cylindrical sintered body 110 also includes the difference between the inner and outer surfaces of the cylinder of the cylindrical sintered body 110. The state of the cylindrical inner surface and the outer surface of the cylindrical sintered body 110 can be evaluated by observation with an electron microscope (SEM). In this embodiment, there are no significant differences in the holes observed at the inner and outer sides of the cylinder at the center of the cylindrical axis direction of the cylindrical sintered body 110. In this embodiment, the shape of the holes observed on the inner and outer surfaces of the cylinder of the cylindrical sintered body 110 is irregular, regardless of the boundaries of the crystal grains or the inside of the crystals. In other words, in the present embodiment, the shape of the pores observed on the inner and outer surfaces of the cylinder of the cylindrical sintered body 110 is irregular bubble-shaped pores regardless of the boundaries of the crystal grains or the inside of the crystal. On the other hand, compared to the cylindrical outer surface of the cylindrical sintered body in the comparative example with a length of 470 mm or more in the direction of the cylindrical axis or the cylindrical inner surface of the cylindrical sintered body 110 in the present embodiment And the outer surface, large irregular granular holes were observed on the inner surface of the cylinder in the comparative example. In other words, irregular crystalline granular holes were observed on the inner side surface of the cylinder of the cylindrical sintered body in the comparative example whose length in the direction of the cylinder axis was 470 mm or more. The pores observed on the inner surface of the cylinder of the cylindrical sintered body in such a comparative example were mainly observed at the boundaries of the crystal grains. There is no significant difference between the outer surface of the cylinder of the cylindrical sintered body in the comparative example and the inner surface and outer surface of the cylinder of the cylindrical sintered body 110 in this embodiment. In the comparative example, whether the crystal grain boundary or the crystal is observed, the holes on the outer side of the cylinder have a smaller irregular grain shape compared to the shape of the holes observed on the inner side of the cylinder of the cylindrical sintered body. .

The shape of each hole observed on the inner side surface and outer side surface of the cylinder of the cylindrical sintered body in this embodiment and the comparative example is an irregular shape. Therefore, it is possible to calculate the area of a single continuous hole in plan view, and then evaluate the size of the hole by the diameter of a circle having an equivalent area (hereinafter, the equivalent circle diameter of the area of the hole). A single continuous hole can be regarded as a single one in the observed surface to calculate the number of holes. The equivalent circle diameter of the area of the pores observed on the inner surface of the cylinder of the cylindrical sintered body 110 in the present embodiment may also be 1 μm or less on average. The equivalent circle diameter of the area of the pores observed on the inner surface of the cylinder of the cylindrical sintered body 110 may be 0.5 μm or less on average. In addition, the number of pores observed on the inner side surface of the cylinder of the cylindrical sintered body 110 in the present embodiment may be an average of 4.25╳10 ^-5 holes / μm ² or less. The number of pores observed on the inner surface of the cylinder of the cylindrical sintered body 110 may be 2.125╳10 ^-5 holes / μm ² or less on average. In addition, the equivalent circle diameter of the area of the pores observed on the cylindrical outer surface of the cylindrical sintered body 110 in the present embodiment may be 1 μm or less on average. The equivalent circle diameter of the area of the pores observed on the outer surface of the cylinder of the cylindrical sintered body 110 may be 0.5 μm or less on average. In addition, the number of pores observed on the outer surface of the cylinder of the cylindrical sintered body 110 in the present embodiment may be 4.25 平均 10 ^-5 holes / μm ² or less on average. The number of holes observed on the outer surface of the cylinder of the cylindrical sintered body 110 may be 2.125╳10 ^-5 holes / μm ² or less on average.

Among them, the evaluation of the state of the inner and outer sides of the cylinder of the cylindrical sintered body 110 was performed by observing five fields of view of 980 μm ╳ 1200 μm in the central portion in the direction of the cylindrical axis of each sample to evaluate the hole The average value of the equivalent circle diameter of the number and the area of the hole. First, the continuous projected area S of a single hole is calculated, and then the diameter L of a circle having an equivalent area can be calculated by the following formula to obtain the equivalent circle diameter L of the area S of the hole.

Equation 1: .

In this embodiment, there is no significant difference in the size of the crystal particles observed on the inner and outer surfaces of the cylinder at the center portion of the cylindrical axis direction of the cylindrical sintered body 110. The large-scale growth of crystal particles observed on the inner and outer surfaces of the cylinder of the cylindrical sintered body 110 in this embodiment. On the other hand, compared with the cylindrical outer surface of the cylindrical sintered body in the comparative example whose length in the direction of the cylindrical axis is 957 mm or more, the crystal particles on the cylindrical inner surface of the comparative example are smaller and observed. Crystal grains in the early stages of growth. Since the crystal particles on the inner surface of the cylinder of the cylindrical sintered body in such a comparative example are in the initial growth stage, the crystal particles are small, uneven and lack smoothness.

Although the details will be described in the manufacturing method, the cylindrical sintered body can be obtained by supplying an oxygen element to the cylindrical forming body along the direction of the cylindrical axis and sintering it.

FIG. 2 is a cross-sectional view showing an example of the structure of a cylindrical sputtering target after assembly according to an embodiment of the present invention. As shown in FIG. 2, in the cylindrical sputtering target 100 after assembly, a cylindrical base material 130 is disposed in a hollow portion inside the cylinder of the cylindrical sintered body 110 shown in FIG. 1. The cylindrical base material 130 and the cylindrical sintered body 110 are mounted with the brazing material 140, and the adjacent cylindrical sintered bodies 110 are arranged through the space 120.

The material of the cylindrical substrate 130 can be a metal material having conductivity sufficient to bias the target and high thermal conductivity, so as to efficiently dissipate electrons or ions when hitting the target when sputtering the target. The heat generated. Specifically, copper (Cu), titanium (Ti), an alloy containing these elements, and stainless steel (SUS) can be used.

As the material of the brazing material 140, a material having sufficient adhesion and strength to maintain the cylindrical sintered body 110 on the cylindrical base material 130 can be used, and this material can have the same conductivity and high conductivity as the cylindrical base material 130. Thermal conductivity. However, the thermal conductivity of the material of the brazing material 140 may also be lower than that of the material of the cylindrical substrate 130. In addition, the conductivity of the material of the brazing material 140 may be lower than that of the material of the cylindrical substrate 130. As the brazing material 140, for example, indium (In), tin (Sn), and an alloy containing these elements can be used.

As described above, according to the sputtering target of the present embodiment, the mechanical strength of the cylindrical sintered body can be improved by setting the length and relative density of the cylindrical sintered body to the above-mentioned ranges, and can obtain The effect of reducing the impurities of the thin film using the cylindrical sintered body and increasing the film density. Furthermore, by setting the relative density difference between the solids and solids of the cylindrical sintered body within the above-mentioned ranges, it is possible to suppress the distortion of the electric field in the divided sputtering target having a plurality of cylindrical sintered bodies. . Therefore, stable discharge characteristics can be obtained during sputtering, and a thin film having extremely high in-plane uniformity can be formed on a large substrate having a size exceeding a single cylindrical sintered body. Furthermore, the states of the inside and outside surfaces of the cylinder of the cylindrical sintered body are set in the above-mentioned ranges, respectively, so that the entire life of the target of the cylindrical sintered body in the divided sputtering target can be stabilized. To maintain quality. In other words, the characteristics of the target are not changed during continuous use, and nodules or particles caused by poor density can be suppressed.

A method of manufacturing the cylindrical sintered body will be described below.

Next, the manufacturing method of the cylindrical sintered body of the cylindrical sputtering target of this invention is demonstrated in detail using FIG. 3. FIG. FIG. 3 shows a flowchart of a method for manufacturing a cylindrical sintered body according to an embodiment of the present invention. Although FIG. 3 illustrates a method for manufacturing an ITO sintered body, the material of the sintered body is not limited to ITO, and other oxidized metal sintered bodies such as IGZO can also be used.

First, prepare the ingredients. As a raw material for mixing, for example, a metal element contained in an oxide or an alloy can be used. The raw material can be a powder material, and the raw material can be appropriately selected according to the composition of the target sputtering target. In the case of ITO, for example, indium oxide powder and tin oxide powder are prepared (steps S301 and S302). The purity of these raw materials is usually 2N (99% by mass) or more, 3N (99.9% by mass) or more, and 4N (99.99% by mass) or more. Since the cylindrical sintered body contains a large amount of impurities when the purity is lower than 2N, problems such as difficulty in obtaining desired material characteristics (such as reduced permeability, increased resistance value of the film, localized foreign matter, and particles due to arcing) may occur. ).

Next, these raw material powders are crushed and mixed (step S303). The raw powder can be pulverized and mixed. It can be dry-processed using spheres or beads of zirconia, alumina, nylon resin, etc. It can also be agitated and ground using the medium of the spheres or beads. The wet method is carried out by a rotary grinder, a containerless grinder, a mechanical agitator grinder, and an air flow grinder. Generally speaking, the wet method has better crushing and mixing ability than the dry method, so the wet method can be used for mixing here.

Although the composition of the raw materials is not particularly limited, it can be appropriately adjusted according to the composition ratio of the target sputtering target.

Here, if a raw material powder having a fine particle diameter is used, the sintered body can be made denser. Although fine powder can be obtained by strengthening the pulverization conditions, if this is the case, the amount of the medium (such as zirconia) used in the pulverization will increase, and the concentration of impurities in the product may increase. In this way, it is necessary to set the conditions at the time of pulverization to an appropriate range while observing the high density of the sintered body and the balance of the impurity concentration in the product.

Next, the slurry of the raw material powder is dried for granulation (step S304). In this case, the slurry may be rapidly dried using a rapid drying granulation method. For the rapid drying granulation method, a spray dryer can be used, and the temperature and volume of hot air can be adjusted. The difference in the specific gravity of the raw material powder will cause the sedimentation speed to be different, so by using a rapid drying granulation method, the separation of the indium oxide powder and the tin oxide powder can be suppressed. With such a granulation method, the proportion of the formula ingredients can be made uniform, thereby improving the handling of the raw material powder. In addition, the sintering process may be performed before and after granulation.

Next, the mixture obtained by the above-mentioned mixing and granulation process (after the sintering process is provided when the sintering process is provided) is press-molded to form a cylindrical forming body (step S305). Through this process, it can be formed into an appropriate shape of the target sputtering target. The length of the cylindrical forming body in the direction of the cylindrical axis can be 600 mm or more. The molding process may be, for example, mold molding, casting molding, injection molding, etc., but in order to obtain a complex shape such as a cylindrical shape, molding may be performed by means of cold equal pressure (CIP). When molding by CIP, first fill the rubber mold with the raw material powder weighed by the specified weight. At this time, by shaking and tapping the rubber mold while filling, it is possible to avoid uneven filling of raw material powder in the mold or generation of voids. The pressure during CIP molding can be 100 MPa or more and 200 MPa or less. By adjusting the pressure at the time of molding as described above, in this embodiment, a cylindrical forming body having a relative density of 54.5% or more and 58.0% or less can be formed. Furthermore, when the pressure during CIP molding is adjusted to 150 MPa or more and 180 MPa or less, a cylinder-shaped body having a relative density of 55.0% or more and 57.5% or less can be obtained.

Next, the cylindrical forming body obtained in the molding process is sintered (step S306). Here, a method for forming a sintered cylinder forming body will be described in detail using FIGS. 4 to 6. FIG. 4 is a perspective view showing a process of sintering a cylindrically formed body in a method of manufacturing a cylindrical sintered body according to an embodiment of the present invention. FIG. 5 is a cross-sectional view illustrating a process of sintering a cylinder-forming body in a method for manufacturing a cylindrical sintered body according to an embodiment of the present invention. In addition, FIG. 6 is a plan view showing a process of sintering a cylindrically formed body in a method for manufacturing a cylindrically sintered body according to an embodiment of the present invention.

First, as shown in FIG. 4, in a state where the cylinder axis direction of the cylindrical forming body 111 is slightly perpendicular to the flat plate-shaped sintering table 200, the cylinder obtained in the molding process of step S305 The forming body 111 is disposed on the sintering table 200. However, as long as the cylindrical forming body 111 can be stably arranged on the sintering table 200, it is not limited to this. For example, the cylindrical forming body 111 may be disposed on the sintering table 200 in an inclined state. In addition, although omitted in FIG. 4, when the cylindrical forming body 111 is sintered, a spacer may be disposed between the cylindrical forming body 111 and the sintering table 200. In this case, the spacer may be arranged to contact the bottom surface 150 with an area smaller than the bottom surface 150 of the cylindrical forming body 111. By arranging the spacer, even if the volume of the cylindrical forming body 111 is reduced in the sintering process, the friction coefficient caused by the movement can be suppressed. Therefore, the internal stress generated in the cylindrical sintered body after sintering can be suppressed.

As shown in FIGS. 5 and 6, the cylindrical forming body 111 obtained in the molding process of step S305 is arranged on the sintering table 200 provided in the chamber 300. The oxygen element supply port 230 provided on the plate-shaped sintering table 200 is arranged at the center of the cylinder, and the cylinder-shaped molding 111 is sintered in this state. Considering that the cylindrical forming body 111 may be reduced due to the sintering process, the oxygen element supply port 230 may be smaller than the inner periphery of the cylindrical forming body 111, so that oxygen elements can be supplied to the inner side surface of the cylinder. In addition, the oxygen element supply port 230 is arranged to supply an oxygen element upward from below the cylinder axis direction of the cylindrical forming body 111. The opening provided in the sintering table 200 may be only the oxygen element supply port 230. A single oxygen element supply port 230 may be directly connected to a single pipe 240 for supplying an oxygen element. The line 240 is connected to the oxygen element supply port 230 from outside the chamber 300 via a controller, a valve, or the like, for example. That is, the oxygen element supplied from the pipeline 240 is not exposed from other areas of the sintering table 200, and the oxygen element supply port 230 selectively supplies oxygen to the inner side surface of the cylinder. With such a configuration, the amount of oxygen element supplied from the oxygen element supply port 230 can be appropriately adjusted in accordance with the length, thickness, and size of the internal space of the cylinder in the cylindrical axis direction of the cylindrical forming body 111. For example, the longer the length in the direction of the cylinder axis, the greater the amount of oxygen element supplied from the oxygen element supply port 230. However, it is not limited to this. For example, when the thickness of the cylindrical forming body 111 is thick, the amount of oxygen element supplied from the oxygen element supply port 230 may be large. In addition, for example, in a case where the inner diameter of the cylindrical sintered body is large or the internal space of the cylinder is large, the amount of oxygen element supplied from the oxygen element supply port 230 may be large.

The upper limit of the amount of the oxygen element supplied from the oxygen element supply port 230 is not particularly limited, but may be 150 L / min or less. When a large amount of oxygen element is supplied through a single oxygen element supply port 230, the cooling effect of the oxygen element may cause deformation, cracking, or density of the cylindrical sintered body during sintering. Problems such as reduction. Therefore, the self-oxygen element supply port 230 may be provided with elements such as a baffle in the direction in which the oxygen element travels. The oxygen element supplied from the oxygen element supply port 230 can also diffuse into the internal space of the cylinder because it collides with elements such as the baffle. Furthermore, the oxygen element supplied from the oxygen element supply port 230 may be heated in advance in a cycle such as a pipeline and then supplied.

In the case where oxygen is supplied to the hollow portion inside the cylinder in an air gas environment, since the oxygen element is heavier than the nitrogen element, the oxygen element can be gradually filled from below the cylinder axis direction. Therefore, it is possible to supply a uniform oxygen element to the inner surface of the cylinder of the cylindrical forming body during sintering. When the oxygen element fills the hollow part inside the cylinder of the cylindrical forming body, the oxygen element that is further supplied can flow out from above the cylindrical forming body to the outside of the cylinder through the hollow part inside the cylinder. The outflowing oxygen element can flow downward from the ceiling portion of the chamber 300, and a cyclic flow of the oxygen element can be generated in the chamber 300. Therefore, the oxygen element concentration in the chamber 300 can also be made uniform. In addition, an oxygen element may be supplied from the wall portion of the chamber 300 to the outside of the cylinder. In this case, by adjusting the oxygen element supply amount to the hollow portion inside the cylinder and the oxygen element supply amount to the outside of the cylinder, the inner and outer sides of the cylinder of the sintered cylinder forming body can be adjusted. The oxygen element concentration is uniform.

Here, although the method of supplying an oxygen element to the hollow part inside the cylinder of the cylindrical formation body 111 from below is illustrated in FIG. 4, it is not limited to this method. For example, the oxygen element may be supplied from below or above the direction of the cylinder axis. By supplying the oxygen element along the cylindrical axis direction of the cylindrical forming body 111, the oxygen element concentration can be uniformly maintained in the cylindrical axis direction during sintering.

In addition, although the method of supplying an oxygen element from the oxygen element supply port 230 arranged in the center of the cylinder of the cylindrical formation body 111 singlely is illustrated in FIG. 4, it is not limited to this method. As long as the oxygen element can be uniformly supplied to the hollow portion inside the cylinder, the oxygen element supply port 230 is limited to the center of the cylinder. The number of the oxygen element supply ports 230 may be plural. The oxygen element may be supplied not only to the inside of the cylinder but also to the outside of the cylinder. At this time, the respective oxygen element supply ports 230 can be independent of each other and can control the amount of oxygen element supply, and can be directly connected to the pipelines 240 for supplying oxygen elements, respectively. Thereby, according to the length, thickness of the cylindrical forming body 111 in the direction of the cylindrical axis, the size of the internal space of the cylinder, and the position of the oxygen element supply port 230 with respect to the cylindrical forming body 111, it is possible to appropriately adjust the respective oxygen The amount of oxygen element supplied from the element supply port 230.

Generally, in the sintering of ITO, it is necessary to perform sintering in an oxygen element gas environment to increase the density of the sintered body. Even if the sintering is performed in an oxygen gas atmosphere, in the process of sintering a cylindrical forming body 111 having a length of 600 mm or more, gas convection in the hollow portion inside the cylinder is insufficient, and the hollow portion inside the cylinder may occur. Insufficient oxygen. If the oxygen content in the hollow part inside the cylinder is insufficient, the cylindrical sintered body may be deformed, cracked during sintering, or the density of the cylindrical sintered body may be reduced after sintering. Problems such as an increase in the relative density difference, an increase in the size of the pores or an increase in the number of pores observed on the inside surface of the cylinder of the cylindrical sintered body, and the like. In order to prevent the influence caused by the insufficient oxygen element in the inner hollow portion, in the present embodiment, as described above, when the sintered cylinder forming body 111 is formed, the self-oxygen element supply port 230 is used for the cylinder forming body 111. The hollow portion on the inner side of the cylinder supplies oxygen element, and the hollow portion on the inner side of the cylinder can be uniformly filled with the oxygen element for the cylindrical forming body 111 having a diameter of 600 mm or more. Furthermore, by combining the supply of oxygen elements to the hollow portion inside the cylinder, that is, the supply of oxygen elements to the outside of the cylinder, the concentration of oxygen elements on the inside and outside surfaces of the cylinder of the sintered cylinder-forming body 111 can be made. Even. As a result, deformation and cracking of the cylindrical sintered body during sintering can be prevented. Moreover, the density of the cylindrical sintered body after sintering can be increased. Furthermore, it is possible to reduce the difference in relative density in the solid of the cylindrical sintered body along the direction of the cylindrical axis. It can also reduce the size and number of holes on the inner side of the cylinder.

The method of manufacturing the cylindrical sintered body will be described below with reference to FIG. 3. In the details described above, the sintering of step S306 can be performed by using an electric furnace, hot equal pressure (HIP), or microwave sintering. Although the sintering conditions can be appropriately selected according to the composition of the sintered body, for example, when ITO containing 10 wt ·% SnO ₂ is used, the temperature can be 1500 ° C to 1600 ° C for 10 minutes in an oxygen element gas environment for 10 minutes. The sintering is performed under the conditions of more than hours and less than 20 hours. Where the sintering temperature is less than 1500 ° C, the density of the target may decrease. On the other hand, if it exceeds 1600 degrees Celsius, the damage to the electric furnace or the furnace material will be increased, and it must be maintained in a timely manner, which may cause a significant reduction in work efficiency. In addition, if the sintering time is less than 10 hours, the density of the target may be reduced. If it is longer than 20 hours, the maintenance time in the sintering process will be prolonged, and the operation efficiency of the electric furnace may be deteriorated. In addition, it may increase the consumption of oxygen element gas used in the sintering process, and increase the electricity used to operate the electric furnace. In addition, the pressure during sintering may be atmospheric pressure, or a reduced-pressure gas environment or a pressurized gas environment.

Here, when electric furnace sintering is used, the occurrence of cracks can be suppressed by adjusting the sintering heating rate and cooling rate. Specifically, the heating rate of the electric furnace during sintering may be 300 ° C or lower per hour, and may be 180 ° C or lower per hour. In addition, the cooling rate of the electric furnace during sintering can be below 600 degrees Celsius per hour. Among them, the heating rate or the cooling rate may be adjusted to be changed stepwise.

Although the cylindrical forming body will shrink due to the sintering process, the temperature in the furnace is uniform before all the materials enter the temperature range where the heat shrinkage starts together, and the temperature is maintained during the heating to eliminate the temperature in the furnace. Uneven, so the entire sintered body set in the furnace can shrink uniformly. Therefore, by setting the arrival temperature and the retention time to appropriate conditions for various materials, a stable sintered body density can be obtained. By sintering a cylinder-shaped body having a length in the direction of the cylindrical axis of 600 mm or more, a cylindrical sintered body having a length in the direction of the cylindrical axis of approximately 470 mm or more can be obtained.

Next, the formed cylindrical sintered body is machined using a machining machine such as a surface grinder, a cylindrical grinder, a lathe, a cutting machine, a machining center, and the like, so that it becomes an intended cylindrical shape. Shape (step S307). The mechanical processing performed here is to process the above-mentioned cylindrical sintered body into a shape suitable for being installed in a sputtering device, and to have a desired surface roughness. Here, in order to obtain flatness to such an extent that abnormal electric field concentration does not occur during sputtering, the average surface roughness (Ra) of the cylindrical sintered body may be set to 0.5 μm or less. Through the above processes, a cylindrical sintered body having high density and high homogeneity can be obtained.

Next, the machined cylindrical sintered body is bonded to the substrate (step S308). In particular, in the case of a cylindrical sputtering target, a cylindrical sintered body is bonded to a cylindrical base material called a backing tube via a brazing material as an adhesive. Through the above process, a cylindrical sputtering target using the cylindrical sintered body can be obtained.

As described above, according to the manufacturing method of the cylindrical sputtering target according to the implementation form, in the sintering process, by supplying oxygen to the hollow portion inside the cylinder of the cylindrical forming body, the circle during sintering can be prevented. Deformation and fracture of cylindrical sintered body. Moreover, the density of the cylindrical sintered body after sintering can be increased. Furthermore, it is possible to reduce the difference in the relative density of the cylindrical sintered body in the direction of the cylindrical axis after sintering. It is also possible to reduce the size of the pores observed on the inner side of the cylinder of the cylindrical sintered body after sintering. In addition, it is possible to reduce the number of holes observed on the inner side surface of the cylinder of the cylindrical sintered body after sintering. The cylindrical sintered body and cylindrical sputtering target that can be provided by this can have high homogeneity in and between solids.

Modification example 1 will be described below.

A sintering method of the cylindrical sintered body according to the first modification of the embodiment of the present invention will be described with reference to FIG. 7.

FIG. 7 is a plan view showing a process of sintering a cylindrically formed body in a method of manufacturing a cylindrical sintered body according to a first modification of the embodiment of the present invention. In the process of forming the sintered cylinder forming body 111 shown in FIG. 7, sixteen oxygen element supply ports 230 are arranged. At this time, the respective oxygen element supply ports 230 can be independent of each other and can control the amount of oxygen element supply, and can be directly connected to the pipelines 240 for supplying oxygen elements, respectively. Thereby, according to the length, thickness of the cylindrical forming body 111 in the direction of the cylindrical axis, the size of the internal space of the cylinder, and the position of the oxygen element supply port 230 with respect to the cylindrical forming body 111, it is possible to appropriately adjust each The amount of oxygen element supplied from the element supply port 230.

In FIG. 7, the wall portions of the cylindrical forming body 111 are sandwiched between eight pairs of oxygen element supply ports 230 and are evenly arranged. In other words, eight oxygen element supply ports 230 are arranged along the inner and outer surfaces of the cylinder of the cylindrical forming body 111, respectively. In FIG. 7, eight oxygen element supply ports 230 a are located inside the cylinder of the cylindrical forming body 111, and eight oxygen element supply ports 230 b are located outside the cylinder of the cylindrical forming body 111. Shape body 111 (hereinafter, when the oxygen element supply port 230a and the oxygen element supply port 230b are not distinguished, it will be referred to as the oxygen element supply port 230). However, it is not limited to this, as long as the cylindrical forming body 111 can be stably arranged on the sintering table 200, the number, size, and arrangement of the oxygen element supply ports 230 are not limited. In addition, the oxygen element supply port 230 is not limited to the inside of the cylinder of the cylindrical forming body 111, and may be located outside the drum. In other words, the oxygen element can be supplied not only to the inner surface of the cylinder but also to the outer surface of the cylinder.

For example, in the case where the length of the cylindrical forming body 111 is long, the oxygen element supply from the oxygen element supply port 230a located inside the cylinder with poor convection is large, and the oxygen element supply from the outside of the cylinder is large. The supply amount of oxygen element in the port 230b is small, thereby adjusting the oxygen element concentration on the inner side surface and the outer side surface of the cylinder to be uniform eventually. Furthermore, the oxygen element may be supplied only from the oxygen element supply port 230a located inside the cylinder. The amount of oxygen element supplied by each oxygen element supply port 230a may be, for example, one-eighth of the supply amount when an oxygen element is supplied from a single oxygen element supply port 230 in the embodiment of the present invention. In addition, the amount of oxygen element supplied by each oxygen element supply port 230a may be uneven or different. That is, the total amount of oxygen element supply from a plurality of oxygen element supply ports 230a may also be the supply amount when an oxygen element is supplied from a single oxygen element supply port 230 in the embodiment of the present invention. In addition, the longer the length in the cylinder axis direction, the more the total amount of oxygen elements supplied from the oxygen element supply port 230a may be. However, it is not limited to this. For example, when the thickness of the cylindrical forming body 111 is thick, the amount of oxygen element supplied from the oxygen element supply port 230 may be large. In addition, for example, in a case where the inner diameter of the cylindrical sintered body is large or the internal space of the cylinder is large, the total amount of oxygen elements supplied from the oxygen element supply port 230a may be large. In addition, for example, in a case where the inner diameter of the cylindrical sintered body is large or the internal space of the cylinder is large, the total amount of oxygen elements supplied from the oxygen element supply port 230a may be large.

The upper limit of the amount of the oxygen element supplied from the oxygen element supply port 230 is not particularly limited, but may be 150 L / min or less. By supplying the oxygen element through the plurality of oxygen element supply ports 230a, the supply amount of the oxygen element can be dispersed, and gas convection in the hollow portion inside the cylinder can be controlled. In addition, problems such as deformation, cracking of the cylindrical sintered body during sintering due to the cooling effect of the oxygen element, and reduction in the density of the cylindrical sintered body after sintering can be suppressed. Therefore, the oxygen element supplied from the plurality of oxygen element supply ports 230a can be diffused in the inner space of the cylinder through elements such as a baffle. Furthermore, the oxygen element supplied from the oxygen element supply port 230 may be heated in advance in a cycle such as a pipeline and then supplied.

Generally, in the sintering of ITO, it is necessary to perform sintering in an oxygen element gas environment to increase the density of the sintered body. Even if the sintering is performed in an oxygen gas atmosphere, in the process of sintering a cylindrical forming body 111 having a length of 600 mm or more, gas convection in the hollow portion inside the cylinder is insufficient, and the hollow portion inside the cylinder may occur. Insufficient oxygen. If the oxygen content in the hollow part inside the cylinder is insufficient, the cylindrical sintered body may be deformed, cracked during sintering, or the density of the cylindrical sintered body may be reduced after sintering. Problems such as an increase in the relative density difference, an increase in the size of the pores or an increase in the number of pores observed on the inside surface of the cylinder of the cylindrical sintered body, and the like. In order to prevent the influence caused by the insufficient oxygen element in the cylinder, in this embodiment, the oxygen element supply from the oxygen element supply port 230a located inside the cylinder is large, and the oxygen located outside the cylinder is large. The supply amount of oxygen element to the element supply port 230b is small, so that the oxygen element concentration on the inner side surface and the outer side surface of the cylinder is finally uniform. By further increasing the oxygen element supply amount from the oxygen element supply port 230a located inside the cylinder, the oxygen element concentration on the inner side surface of the cylinder can finally be adjusted to be greater than the oxygen element concentration on the outer side surface of the cylinder. Furthermore, it may be adjusted so that the oxygen element is supplied only from the oxygen element supply port 230a located inside the cylinder, and the oxygen element is not supplied from the oxygen element supply port 230b located outside the cylinder. The respective oxygen element supply ports 230 can be independent of each other and can control the supply amount of the oxygen element, and can be directly connected to the pipelines 240 for supplying the oxygen element, respectively. By supplying the oxygen element from the plurality of oxygen element supply ports 230a, the oxygen element can be more uniformly supplied to the inner side surface of the cylinder. As a result, it is possible to adjust the oxygen element concentration on the inner and outer surfaces of the cylinder of the cylindrical forming body during sintering, and to prevent deformation and cracking of the cylindrical sintered body during sintering. Moreover, the density of the cylindrical sintered body after sintering can be increased. Furthermore, it is possible to reduce the difference in the relative density of the cylindrical sintered body in the direction of the cylindrical axis after sintering. It is also possible to reduce the equivalent circle diameter of the hole area observed on the inner side of the cylinder of the cylindrical sintered body after sintering. In addition, it is possible to reduce the number of holes observed on the inner side surface of the cylinder of the cylindrical sintered body after sintering.

Modification 2 will be described below.

A sintering method of a cylindrical sintered body according to Modification 2 of the embodiment of the present invention will be described with reference to FIG. 8. In this modification, since the embodiment is the same as the embodiment of the present invention except the baffle 260, detailed descriptions thereof will be omitted.

FIG. 8 is a cross-sectional view illustrating a process of sintering a cylindrically formed body in a method of manufacturing a cylindrical sintered body according to a second modification of the embodiment of the present invention. In the process of forming the sintered cylinder forming body 111 shown in FIG. 8, a single oxygen element supply port 230 is arranged. The oxygen element supply port 230 may be capable of independently controlling the supply amount of the oxygen element, and may be directly connected to the pipeline 240 for supplying the oxygen element. A baffle 260 is disposed in the oxygen element traveling direction from the oxygen element supply port 230. In this modification, the baffle 260 has a hat-like shape surrounding the oxygen element supply port 230. The baffle 260 has a plurality of openings 280 in a hat-shaped side wall portion. Therefore, the oxygen element supplied from the oxygen element supply port 230 hits the inner ceiling portion of the baffle plate 260 and flows out from the plurality of opening portions 280 of the baffle plate 260 in a diffused state. The oxygen element flowing out from the plurality of openings 280 of the baffle 260 may gradually fill the hollow portion inside the cylindrical forming body from below the direction of the cylindrical axis, and rise along the direction of the cylindrical axis. However, the shape of the baffle 260 is not limited to this, and the shape of the baffle 260 may be such that the oxygen element supplied from the oxygen element supply port 230 can be diffused into the inner space of the cylinder. For example, viewed from the traveling direction of the oxygen element, the baffle 260 may overlap at least a part of the oxygen element supply port 230. Originally, when a large amount of oxygen was supplied from a single oxygen element supply port 230, the cooling effect of the oxygen element may cause problems such as deformation, cracking of the cylindrical sintered body during sintering, or reduction in the density of the cylindrical sintered body after sintering. . The above-mentioned problem can be suppressed by the second modification.

However, the present invention is not limited to the above-mentioned embodiments, and can be appropriately modified without departing from the gist.

The production of the cylindrical sintered body of the examples will be described below.

Embodiment 1 will be described below.

In Example 1, a method for manufacturing a cylindrical ITO target (cylindrical sintered body) will be described. First, a 4N indium oxide having a BET (Brunauer Emmet and Teller's equation) specific surface area of 4.0 m ² / g or more and 6.0 m ² / g or less and a BET specific surface area of 4.0 m ² / g or more and 5.7 m ² / g are prepared. The following 4N tin oxide is used as the raw material powder. Here, the BET specific surface area indicates a surface area obtained by a BET method. The BET method is a gas adsorption method in which gas molecules such as nitrogen, argon, krypton, and carbon monoxide are adsorbed on solid particles, and the specific surface area of the solid particles is measured from the amount of the adsorbed gas molecules. Here, 90% by mass of indium oxide and 10% by mass of tin oxide were used as raw materials. These raw powders were then pulverized and mixed using a wet ball mill. Here, zirconia spheres are used as the pulverizing medium. The mixed slurry was rapidly dried and granulated by a spray dryer.

Next, the mixture obtained by the granulation process described above was formed into a cylindrical shape by CIP molding. The pressure during molding with CIP was 176 MPa.

The parameters of the cylindrical forming body of Example 1 obtained by the above molding process are as follows.

Cylinder outer diameter (diameter) = 194.0 mm.

Cylinder inner diameter (diameter) = 158.7 mm.

The thickness of the cylinder = 17.65mm.

Length in the direction of the cylinder axis = 600mm.

Next, a cylindrical shaped body obtained by sintering CIP using an electric furnace was used. The sintering conditions are as follows.

Heating rate = 300 degrees Celsius / hour.

High temperature maintenance temperature = 1560 degrees Celsius.

High temperature maintenance time = 20 hours.

Gas environment during sintering = oxygen element gas environment.

Pressure during sintering = atmospheric pressure.

Oxygen element introduced into the hollow part inside the cylinder = 50L / min.

The oxygen element introduced to the outside of the cylinder = 0 L / min.

The parameters of the cylindrical sintered body obtained by the above sintering process are as follows.

Cylinder outer diameter (diameter) = 155.2mm.

Cylinder inner diameter (diameter) = 127.0mm.

The thickness of the cylinder is = 14.1mm.

Length in the direction of the cylinder axis = 478mm.

Sintered body density = 7.134 g / cm ³ .

The relative density of the sintered body = 99.68%.

Bulk impedance of the sintered body = 0.11 mΩ. cm.

Embodiment 2 will be described below.

In Example 2, it will be explained that the length in the axial direction of the sintered cylinder is larger than the actual length. A cylindrical sintered body formed of the cylindrical forming body of Example 1. Since the forming process of the cylindrical forming body is the same as that of the first embodiment, the description thereof is omitted.

The parameters of the cylindrical forming body of Example 2 obtained by the same molding process as in Example 1 are as follows.

Cylinder outer diameter (diameter) = 193.8mm.

Inner diameter (diameter) of the cylinder = 158.2mm.

The thickness of the cylinder = 17.8mm.

Length in the direction of the cylinder axis = 1200mm.

Next, the cylindrical body was sintered using an electric furnace. The sintering conditions of Example 2 are the same as those of Example 1 except for the oxygen element parameters introduced into the hollow portion on the inner side of the cylinder, so the description is omitted.

Oxygen element introduced into the hollow part inside the cylinder = 100L / min.

The oxygen element introduced to the outside of the cylinder = 0 L / min.

The parameters of the cylindrical sintered body obtained by the above sintering process are as follows.

Cylinder outer diameter (diameter) = 155.0mm.

Cylinder inner diameter (diameter) = 126.6mm.

The thickness of the cylinder is 14.2mm.

Length in the direction of the cylinder axis = 948mm.

Sintered body density = 7.132 g / cm ³ .

The relative density of the sintered body = 99.65%.

The block impedance of the sintered body = 0.12 mΩ. cm.

Embodiment 3 will be described below.

In Example 3, a cylindrical sintered body in which the length in the axial direction of the sintered cylinder is larger than the cylindrical forming bodies of Examples 1 and 2 will be described. Since the forming process of the cylindrical forming body is the same as that of the first embodiment, the description thereof is omitted.

The parameters of the cylindrical forming body of Example 3 obtained by the same molding process as in Example 1 are as follows.

Cylinder outer diameter (diameter) = 194.2mm.

Inner diameter (diameter) of the cylinder = 158.5mm.

The thickness of the cylinder = 17.85mm.

The length in the direction of the cylinder axis = 1755mm.

Next, the cylindrical body was sintered using an electric furnace. The sintering conditions of Example 3 are the same as those of Example 1 except for the oxygen element parameters introduced into the hollow portion on the inner side of the cylinder, so the description is omitted.

Oxygen element introduced into the hollow part inside the cylinder = 150L / min.

The oxygen element introduced to the outside of the cylinder = 0 L / min.

The parameters of the cylindrical sintered body obtained by the above sintering process are as follows.

Cylinder outer diameter (diameter) = 155.4mm.

Cylinder inner diameter (diameter) = 126.8mm.

The thickness of the cylinder is 14.3mm.

Length in the direction of the cylinder axis = 1386mm.

Sintered body density = 7.130 g / cm ³ .

The relative density of the sintered body = 99.62%.

The block impedance of the sintered body = 0.12 mΩ. cm.

Next, a comparative example with respect to the cylindrical forming body and the cylindrical sintered body shown in Examples 1 to 3 described above will be described below. The following comparative examples are different from the examples. In the comparative examples, a cylindrical sintered body that is sintered under the condition that the oxygen element is not introduced into the hollow portion inside the cylindrical forming body will be described. Among them, in the comparative example, instead of introducing the oxygen element into the hollow portion inside the cylindrical forming body, sintering was performed under the condition that the oxygen element was introduced into the cylindrical forming body outside. Since the forming process of the cylindrical forming body is the same as that of the first embodiment, the description thereof is omitted.

Comparative Example 1 will be described below.

The parameters of the cylindrical forming body of Comparative Example 1 obtained by the same molding process as in Example 1 are as follows.

Cylinder outer diameter (diameter) = 194.9mm.

Cylinder inner diameter (diameter) = 159.0mm.

The thickness of the cylinder = 17.95mm.

Length in the direction of the cylinder axis = 480mm.

Next, the cylindrical body was sintered using an electric furnace. The sintering conditions of Comparative Example 1 are the same as those of Example 1 except for the parameters of the oxygen element introduced into the cylindrical forming body, and therefore descriptions thereof are omitted.

The oxygen element introduced into the hollow part inside the cylinder = 0 L / min.

Oxygen element introduced to the outside of the cylinder = 100L / min.

The parameters of the cylindrical sintered body obtained through the above sintering process are as follows Described below.

Cylinder outer diameter (diameter) = 155.9mm.

Inner diameter (diameter) of the cylinder = 127.2mm.

The thickness of the cylinder is 14.35mm.

Length in the direction of the cylinder axis = 385mm.

Sintered body density = 7.133 g / cm ³ .

The relative density of the sintered body = 99.66%.

The block impedance value of the sintered body = 0.11mΩ. cm.

Comparative Example 2 will be described below.

The parameters of the cylindrical forming body of Comparative Example 2 obtained by the same molding process as in Example 1 are as follows.

Cylinder outer diameter (diameter) = 193.5mm.

Inner diameter (diameter) of the cylinder = 158.2mm.

The thickness of the cylinder = 17.65mm.

Length in the direction of the cylinder axis = 600mm.

Next, the cylindrical body was sintered using an electric furnace. The sintering conditions of Comparative Example 2 are the same as those of Example 1 except for the parameters of the oxygen element introduced into the cylindrical forming body, and their descriptions are omitted.

The oxygen element introduced into the hollow part inside the cylinder = 0 L / min.

Oxygen element introduced to the outside of the cylinder = 100L / min.

The parameters of the cylindrical sintered body obtained by the above sintering process are as follows.

Cylinder outer diameter (diameter) = 156.7mm.

Inner diameter (diameter) of the cylinder = 128.1mm.

The thickness of the cylinder is 14.3mm.

Length in the direction of the cylinder axis = 485mm.

Sintered body density = 7.041 g / cm ³ .

The relative density of the sintered body = 98.38%.

The block impedance of the sintered body = 0.12 mΩ. cm.

Comparative Example 3 will be described below.

The parameters of the cylindrical forming body of Comparative Example 3 obtained in the same molding process as in Example 1 are as follows.

Cylinder outer diameter (diameter) = 194.1mm.

Inner diameter (diameter) of the cylinder = 158.2mm.

The thickness of the cylinder = 17.95mm.

Length in the direction of the cylinder axis = 1200mm.

Next, the cylindrical body was sintered using an electric furnace. The sintering conditions of Comparative Example 3 are the same as those of Example 1 except for the parameters of the oxygen element introduced into the cylindrical forming body, and their descriptions are omitted.

The oxygen element introduced into the hollow part inside the cylinder = 0 L / min.

Oxygen element introduced to the outside of the cylinder = 100L / min.

The parameters of the cylindrical sintered body obtained by the above sintering process are as follows.

Cylinder outer diameter (diameter) = 157.2mm.

Inner diameter (diameter) of the cylinder = 128.1mm.

The thickness of the cylinder = 14.55mm.

Length in the direction of the cylinder axis = 957mm.

Sintered body density = 7.038 g / cm ³ .

The relative density of the sintered body = 98.34%.

The block impedance of the sintered body = 0.12 mΩ. cm.

Among them, Comparative Example 3 confirmed deformation due to sintering.

Comparative Example 4 will be described below.

The parameters of the cylindrical forming body of Comparative Example 4 obtained in the same molding process as in Example 1 are as follows.

Cylinder outer diameter (diameter) = 194.2mm.

Cylinder inner diameter (diameter) = 158.4mm.

The thickness of the cylinder is 17.9mm.

The length in the direction of the cylinder axis = 1410mm.

Next, the cylindrical body was sintered using an electric furnace. The sintering conditions of Comparative Example 4 are the same as those of Example 1 except for the parameters of the oxygen element introduced into the cylindrical forming body, and therefore descriptions thereof are omitted.

The oxygen element introduced into the hollow part inside the cylinder = 0 L / min.

Oxygen element introduced to the outside of the cylinder = 100L / min.

The parameters of the cylindrical sintered body obtained by the above sintering process are as follows.

Cylinder outer diameter (diameter) = 155.3mm.

Cylinder inner diameter (diameter) = 127.8mm.

The thickness of the cylinder = 13.75mm.

Length in the direction of the cylinder axis = 1145mm.

Sintered body density = 7.042 g / cm ³ .

The relative density of the sintered body = 98.39%.

The block impedance of the sintered body = 0.12 mΩ. cm.

Comparative Example 5 will be described below.

The parameters of the cylindrical forming body of Comparative Example 5 obtained in the same molding process as in Example 1 are as follows.

Cylinder outer diameter (diameter) = 193.6mm.

Cylinder inner diameter (diameter) = 158.3mm.

The thickness of the cylinder = 17.65mm.

Length in the direction of the cylinder axis = 1754mm.

Next, the cylindrical body was sintered using an electric furnace. The sintering conditions of Comparative Example 5 are the same as those of Example 1 except for the parameters of the oxygen element introduced into the cylindrical forming body, and their descriptions are omitted.

The oxygen element introduced into the hollow part inside the cylinder = 0 L / min.

Oxygen element introduced to the outside of the cylinder = 100L / min.

The parameters of the cylindrical sintered body obtained by the above sintering process are as follows.

Cylinder outer diameter (diameter) = 157.8mm.

Cylinder inner diameter (diameter) = 128.5mm.

The thickness of the cylinder = 14.65mm.

Length in the direction of the cylinder axis = 1394mm.

Sintered body density = 7.044 g / cm ³ .

The relative density of the sintered body = 98.42%.

The block impedance of the sintered body = 0.12 mΩ. cm.

The preparation of measurement samples will be explained below.

For the cylindrical sintered bodies of Examples 1 to 3 and Comparative Examples 1 to 5 described above, measurement samples were prepared for evaluating the internal deviation of the solid and the impedance of the bulk. As shown in FIG. 9, the cylindrical sintered body 110 is segmented every 150 mm from the direction of the cylindrical axis direction upwards during sintering, and then a cylinder with a width of 40 to 50 mm is cut at the central part of each cylindrical axis direction. Shape measurement sample. 110-1 (150mm), 110-25 (300mm), 110-3 (450mm) (the names in the table to be described later) in this order from below the cylindrical shaft.

The evaluation of the relative density will be described below.

The relative density of the cylindrical sintered body and each measurement sample of the above-mentioned Examples 1 to 3 and Comparative Examples 1 to 5 was evaluated. The Archimedes method was used to measure the density of the cylindrical sintered body and each measurement sample. Based on the theoretical density, the relative density and the difference in relative density of the cylindrical sintered body and each measurement sample were calculated. FIG. 10 shows the density, relative density, and maximum relative density difference between the cylindrical sintered body and each measurement sample in Examples 1 to 3 and Comparative Examples 1 to 5.

As can be seen from the results of FIG. 10, compared with the cylindrical sintered bodies of Comparative Examples 2 to 5 in which the oxygen element was not introduced into the hollow portion inside the cylindrical forming body during sintering, the oxygen element was introduced during sintering. Examples 1 to 1 to the inner hollow portion of the cylindrical forming body The relative density of the cylindrical sintered body of 3 is relatively increased. In Comparative Example 1 in which the length in the direction of the cylinder axis was 470 mm or less, even if the oxygen element was not introduced into the inner hollow portion of the cylinder forming body, the relative density was improved. Compared with the measurement samples of Comparative Examples 2 to 5, each measurement sample of Examples 1 to 3 can reduce the difference in relative density. In Comparative Example 1 in which the length in the direction of the cylinder axis was 470 mm or less, even if the oxygen element was not introduced into the inner hollow portion of the cylindrical forming body, the difference in relative density could be reduced. Therefore, by supplying oxygen element to the inner side surface of the cylinder of the cylindrical forming body in the sintering process, the cylindrical forming body having a length in the direction of the cylindrical axis of 1200 mm or more can also prevent problems such as deformation and cracking during sintering. .

The evaluation of the minimum oxygen element supply amount will be described below.

According to the sintering method of the cylindrical forming body in the above examples and comparative examples, the minimum supply amount of oxygen element to obtain a cylindrical sintered body having a density of 7.130 g / cm ³ or more was obtained. Specifically, the amount of oxygen element introduced into the hollow portion inside the cylinder during stepwise sintering was changed to obtain a cylindrical sintered body having a length in the direction of the cylinder axis of 390, 480, 950, 1200, or 1400 mm. The density of each cylindrical sintered body was measured using the Archimedes method. For cylindrical sintered bodies with a density of 7.130 g / cm ³ or more, the length in the direction of the axis of each cylinder is used as the difference, and the value of the minimum amount of oxygen element introduced during sintering is used as the minimum oxygen element supply amount. FIG. 11 shows the relationship between the minimum oxygen element supply amount and the length in the cylindrical axis direction of the cylindrical sintered body.

As shown in FIG. 11, when the length in the cylindrical axis direction of the cylindrical sintered body is 390 mm, a cylindrical sintered body having a density of 7.130 g / cm ³ or more can be obtained even if no oxygen element is introduced. When a cylindrical sintered body of 480 mm is formed, the minimum oxygen element supply amount is 5 L / min or more. When forming a cylindrical sintered body of 950 mm, the minimum oxygen element supply amount is 20 L / min or more. When forming a cylindrical sintered body of 1200 mm, the minimum supply amount of oxygen element is 30 L / min or more. When forming a cylindrical sintered body of 1400 mm, the minimum supply amount of oxygen element is 35 L / min or more. As can be seen from the results in FIG. 11, the longer the length in the direction of the cylinder axis, the more the amount of oxygen element required to obtain a cylindrical sintered body having a density of 7.130 g / cm ³ or more. The length in the axial direction of the cylindrical sintered body having a density of 7.130 g / cm ³ or more is set to X (mm), and the minimum supply amount of oxygen element supplied from the oxygen element supply port 230 is set to Y (L / min), and the ratio is The relationship can be expressed by the following formula.

Y = 0.0345X-12.508.

The evaluation of the block impedance will be described below.

For the cylindrical sintered bodies and the respective measurement samples of Examples 1 to 3 and Comparative Examples 1 to 5, the bulk impedances were evaluated. The four-probe method was used to measure the cylindrical sintered body and the block impedance of each measurement sample on the outer side of the cylinder. FIG. 12 shows the impedance values of the cylindrical sintered body and the bulk impedance of each measurement sample in Examples 1 to 3 and Comparative Examples 1 to 5. FIG.

As can be seen from the results in FIG. 12, the cylindrical sintered bodies of Examples 1 to 3 and Comparative Examples 1 to 5 and the various measurement samples had almost no change in the impedance value of the bulk on the outer surface of the cylinder. Since the outer surface of the cylinder is sufficiently supplied with oxygen elements, both the embodiment in which the oxygen element is introduced into the hollow portion inside the cylinder and the comparative example in which the oxygen element is not introduced into the hollow portion inside the cylinder are introduced. It can be considered that it has almost no effect on the impedance value of the block on the outer side of the cylinder.

The preparation of the sample for electron microscope observation will be described below.

For the cylindrical sintered bodies of Examples 1 and 2 and Comparative Examples 2 and 3, samples were prepared for observation with an electron microscope. As shown in FIG. 13, a cylindrical sample 110-4 having a width of 10 mm was cut out from the cylindrical sintered body 110 at the center of the cylindrical axis direction, and the cylindrical inner surface 110-4a and the cylindrical outer surface 110-4b were cut out. A sample for observation with an electron microscope was cut out, and mirror-polished with 0.5 mm of polishing.

The observation by an electron microscope will be described below.

With respect to the cylindrical sintered bodies of Examples 1 and 2 and Comparative Examples 2 and 3 described above, electron microscope observation samples of the cylindrical inner and outer surfaces of the cylindrical sintered body were observed using an electron microscope (SEM). In each sample, photographs observed under a 1000-fold field of view using an electron microscope (SEM) are shown in FIG. 14 (inside the cylinder) and FIG. 15 (outside of the cylinder). In addition, in each sample, photographs observed under a field of view of 2000 or 5000 times using an electron microscope (SEM) are shown in FIG. 16 (inside the cylinder) and FIG. 17 (outside of the cylinder). In FIGS. 14 to 17, the circles of the cylindrical sintered body of (a) Example 1, (b) Example 2, (c) Comparative Example 2, and (d) Comparative Example 3 were observed using an electron microscope (SEM). Samples for electron microscope observation of the inside and outside surfaces of the tube.

(A) and (b) of FIG. 14 are electron microscope photographs of the inside surface of the cylindrical sintered body in Examples 1 and 2. 15 (a) and (b) are electron micrographs of the outer surface of the cylindrical sintered body in Examples 1 and 2. FIG. (C) and (d) of FIG. 14 are electron microscope photographs of the inside surface of the cylindrical sintered body in Comparative Examples 2 and 3. (C) and (d) of FIG. 15 are electron microscope photographs of the outer surface of the cylindrical sintered body in Comparative Examples 2 and 3. As shown in FIGS. 14 and 15, in Examples 1 and 2 in which the oxygen element is introduced into the hollow portion inside the cylinder during the sintering, the inside surface of the cylindrical sintered body (FIG. 14 (a)) And (b)) and the electron microscope photographs of the outer surface (Figures 15 (a) and (b)) did not show significant differences. On the other hand, in Comparative Example 2 and Comparative Example 3, in which the oxygen element was not introduced into the hollow portion on the inner side of the cylinder during the sintering, the outer surface of the cylindrical sintered body was compared with that of the outer side (Fig. (D)), a large number of large holes were observed in the electron microscope photograph of the inside of the cylindrical sintered body (Figures 14 (c) and (d)) (black irregular patterns in the photograph). A large number of irregular granular (crystalline granular) holes were observed on the inner side surface of the cylinder of the cylindrical sintered body in Comparative Examples 2 and 3. The pores observed on the inner surface of the cylinder of the cylindrical sintered body in Comparative Examples 2 and 3 were mainly observed at the crystal grain boundaries.

Next, in order to observe the state of the crystal particles, particularly in the comparative example, the areas where large holes are not observed are observed in (c) and (d) of FIG. 14 at a field of view of 2000 or 5000 times. (A) and (b) of FIG. 16 are electron microscope photographs of the inside surface of the cylindrical sintered body in Examples 1 and 2. 17 (a) and 17 (b) are electron micrographs of the outer surface of the cylindrical sintered body in Examples 1 and 2. FIG. (C) and (d) of FIG. 16 are electron microscope photographs of the inside surfaces of the cylindrical sintered bodies in Comparative Examples 2 and 3. (C) and (d) of FIG. 17 are electron microscope photographs of the outer surface of the cylindrical sintered body in Comparative Examples 2 and 3. As shown in FIGS. 16 and 17, in Examples 1 and 2 in which the oxygen element is introduced into the hollow portion on the inner side of the cylinder during the sintering, the inside surface of the cylindrical sintered body (FIG. And (b)) and the electron microscope photographs of the outer surface (Fig. 17 (a) and (b)) did not observe any significant difference, and large-scale growth of crystal particles. During the sintering, no oxygen element was introduced into the hollow portion of the inner side of the cylinder of the cylindrical forming body, and the length of the cylindrical axis of Comparative Example 2 was shorter than that of Comparative Example 3. In Comparative Example 2, the side of the cylindrical sintered body No significant difference was observed in the electron microscope photographs of Fig. 16 (c)) and the outer surface (Fig. 17 (c)), and large-scale growth of crystal particles was observed. On the other hand, during the sintering, no oxygen element was introduced into the hollow portion of the inner side of the cylinder of the cylindrical forming body, and the length of the cylindrical axis of Comparative Example 3 was larger than that of Comparative Example 2. In Comparative Example 3, compared with Electron microscopy images of the outer surface of the cylindrical sintered body (Fig. 17 (d)) and the inner surface of the cylindrical sintered body (Fig. 16 (d)) showed small-sized crystal particles that were in the initial stage of growth. In Comparative Example 3, since the crystal particles on the inner surface of the cylindrical sintered body were in the initial stage of growth, the crystal particles were small, uneven, and lacking in smoothness.

Small irregular grain-shaped (bubble-like) holes were observed on the inner and outer surfaces of the cylinders of the cylindrical sintered bodies of Examples 1 and 2 (for example, the upper-left hole in FIG. 17 (b)). Also in the cylindrical outer surfaces of the cylindrical sintered bodies of Comparative Examples 2 and 3, the same small irregular grain shape (bubble-like) holes were observed. Regardless of whether the boundaries of the crystal grains or the inside of the crystals are observed, the inner sides of the cylinders of the cylindrical sintered bodies of Examples 1 and 2 and the cylindrical sintered bodies of Comparative Examples 2 and 3 can be observed. Holes observed from the outside.

Evaluation of the pores on the side of the cylindrical sintered body will be described below.

In the cylindrical sintered bodies of Examples 1 to 3 and Comparative Examples 1 to 5, the electron microscope (SEM) was used to observe the cylindrical sintered body in the cylinder at the central portion in the direction of the cylindrical axis using the method described above. The structure of the side and the outer side, and measure the number of holes and the equivalent circle diameter of the area of the holes. Each of the samples was five electron microscope observation samples cut out from the inner side surface 110-4a of the cylindrical sample 110-4 along the circumferential direction. A field of view of 980 μm to 1200 μm was observed from each electron microscope observation sample to calculate the average number of holes and the equivalent circle diameter of the area of the holes. The equivalent circle diameter L of the area S of the hole in the cylindrical sintered body was calculated by the following formula.

Equation 1: .

FIG. 18 shows the average value of the equivalent circle diameter of the number of holes and the area of the holes on the inner side surface of the cylinder of the cylindrical sintered body of Examples 1 to 3 and Comparative Examples 1 to 5. FIG.

From the results shown in FIG. 18, compared with the cylindrical sintered bodies of Comparative Examples 2 to 5 in which the oxygen element was not introduced into the hollow portion inside the cylinder of the cylindrical forming body during sintering, the The cylindrical sintered bodies of Examples 1 to 3 in which the elements were introduced into the hollow portion on the inner side of the cylinder of the cylindrical forming body had a small number of holes on the inner side surface of the cylinder. In Comparative Example 1 in which the length in the direction of the cylinder axis was 470 mm or less, even if the oxygen element was not introduced into the inner hollow portion of the cylinder forming body, the number of holes in the inner side surface of the cylinder was small. In the cylindrical inner surface of the cylindrical sintered body of Examples 1 to 3, the average value of the equivalent circle diameter of the area of the holes was 1 μm or less. On the other hand, in the cylindrical inner surface of the cylindrical sintered bodies of Comparative Examples 2 to 5, the average value of the equivalent circle diameter of the area of the holes was 4 μm or more. In Comparative Example 1 in which the length in the direction of the cylinder axis is 470 mm or less, the average equivalent circle diameter of the area of the holes on the inner side surface of the cylinder is averaged even if oxygen is not introduced into the inner hollow portion of the cylinder forming body. The value may be 1 μm or less. In addition, as shown in FIG. 18, the number of holes observed on the outer surface of the cylinder of the cylindrical sintered bodies of Examples 1 to 3 and Comparative Examples 1 to 5 may be 4.254.210 ^-5 holes / μm ² or less. The average value of the equivalent circle diameter of the hole area can be 1 μm or less.

Although the results of ITO are shown in Examples 1 to 3, the same can be used for a cylindrically formed body having a length of 600 mm or more in the direction of the cylinder axis composed of various components of IZO, IGZO, and AZO The manufacturing method of the invention performs sintering. However, the manufacturing conditions can be appropriately changed in accordance with the respective components within the scope of the present invention. As a result, deformation and cracking of the cylindrical sintered body during sintering can be prevented. Moreover, the density of the cylindrical sintered body after sintering can be increased. Furthermore, it is possible to reduce the difference in the relative density of the cylindrical sintered body in the direction of the cylindrical axis after sintering. It is also possible to reduce the equivalent circle diameter of the hole area observed on the inner side of the cylinder of the cylindrical sintered body after sintering. In addition, it is possible to reduce the number of holes observed on the inner side surface of the cylinder of the cylindrical sintered body after sintering.

However, the present invention is not limited to the above-mentioned embodiments, and can be appropriately changed without departing from the gist.

100‧‧‧ cylindrical sputtering target
110, 110a, 110b‧‧‧ cylindrical sintered body
110-1, 110-2, 110-3‧‧‧ Measured samples
110-4‧‧‧ cylindrical sample
110-4a‧‧‧Cylinder inner side
110-4b‧‧‧Cylinder outer side
111‧‧‧ cylindrical forming body
120‧‧‧ space
130‧‧‧ cylindrical substrate
140‧‧‧ brazing material
150‧‧‧ underside
200‧‧‧Sintering table
230, 230a, 230b‧‧‧oxygen supply port
240‧‧‧ pipeline
260‧‧‧ Bezel
280‧‧‧ opening
300‧‧‧ chamber

FIG. 1 is a perspective view showing an example of a cylindrical sintered body included in a cylindrical sputtering target according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing an example of the structure of a cylindrical sputtering target after assembly according to an embodiment of the present invention. FIG. 3 shows a flowchart of a method for manufacturing a cylindrical sintered body according to an embodiment of the present invention. FIG. 4 is a perspective view illustrating a process of sintering a cylindrically formed body in a method for manufacturing a cylindrically sintered body according to an embodiment of the present invention. FIG. 5 is a cross-sectional view showing a process of sintering a cylinder-forming body in a method for manufacturing a cylindrical sintered body according to an embodiment of the present invention. FIG. 6 is a plan view of a process for sintering a cylindrically formed body in a method for manufacturing a cylindrically sintered body according to an embodiment of the present invention.

FIG. 7 is a plan view showing a process for sintering a cylindrically formed body in a method for manufacturing a cylindrical sintered body according to a first modification of the embodiment of the present invention.

FIG. 8 is a cross-sectional view illustrating a process of sintering a cylinder-forming body in a method for manufacturing a cylindrical sintered body according to a second modification of an embodiment of the present invention.

FIG. 9 is a schematic diagram showing the positions where the measurement samples are taken along the cylindrical axis direction in the cylindrical sintered body according to the embodiment and the comparative example of the present invention.

FIG. 10 is a table showing the density, the density difference in the solid, the relative density, and the maximum relative density difference in the solid of the cylindrical sintered body according to the examples and comparative examples of the present invention.

FIG. 11 is a schematic diagram showing the relationship between the length of the cylindrical sintered body and the minimum oxygen element supply amount in the examples and comparative examples of the present invention.

FIG. 12 is a table showing the difference between the bulk impedance and the solid bulk impedance of the cylindrical sintered body in the examples and comparative examples of the present invention.

FIG. 13 is a schematic diagram showing the positions where the measurement samples are taken along the inner and outer sides of the cylinder in the cylindrical sintered body according to the embodiment and the comparative example of the present invention.

FIG. 14 is a photograph of an electron microscope (SEM, 1000 times) of a cylindrical inner surface of a cylindrical sintered body according to examples and comparative examples of the present invention.

FIG. 15 is a photograph of an electron microscope (SEM, 1000 times) of a cylindrical outer surface of a cylindrical sintered body according to the examples and comparative examples of the present invention.

FIG. 16 is a photograph of an electron microscope (SEM, 5000 × or 2000 ×) of a cylindrical inner surface of a cylindrical sintered body according to the examples and comparative examples of the present invention.

FIG. 17 is a photograph of an electron microscope (SEM, 5000 times) of a cylindrical outer surface of a cylindrical sintered body according to the examples and comparative examples of the present invention. FIG. 18 is a table showing the average values of the equivalent circle diameters and the numbers of the areas of the holes on the inner surface of the cylinder of the cylindrical sintered body according to the examples and comparative examples of the present invention.

Claims (11)

A method for manufacturing a cylindrical sintered body, comprising: arranging a cylindrical forming body on a workbench, the length of the cylindrical forming body in a direction of a cylindrical axis is 600 mm or more, and the workbench is provided with an oxygen element supply port The oxygen element supply port is connected to a pipeline for providing an oxygen element; and the oxygen element is supplied from the oxygen element supply port in the direction of the cylinder axis and sintered, and the oxygen element supply port is smaller than the circle provided in the circle. The inner circumference of the cylinder inside the cylinder of the cylinder forming body. The method for manufacturing a cylindrical sintered body according to claim 1, wherein the table is arranged in a chamber, and the pipeline for supplying the oxygen element is connected to the oxygen element supply from outside the chamber mouth. The method for producing a cylindrical sintered body according to claim 2, wherein the oxygen element is supplied to a hollow portion inside the cylinder of the cylindrical forming body and sintered. The method for manufacturing a cylindrical sintered body according to claim 3, wherein the oxygen element is supplied upward from below the cylinder axis direction of the cylindrical forming body and sintered. A manufacturing method of a sputtering target, comprising manufacturing the cylindrical sintered body by the manufacturing method of the cylindrical sintered body according to any one of claims 1 to 4, and installing the cylindrical sintered body On a substrate. A cylindrical sintered body manufactured by the method for manufacturing a cylindrical sintered body according to any one of claims 1 to 4, is a cylindrical sintered body having a length of 470 mm or more along a cylindrical axis direction, and is along the circle The relative density difference in the cylinder axis direction is within 0.1%. A cylindrical sintered body manufactured by the method for manufacturing a cylindrical sintered body according to any one of claims 1 to 4, is a cylindrical sintered body having a length of 470 mm or more along a cylindrical axis direction, and The equivalent circle diameter of the area of the pores observed on the inner surface is 1 μm or less on average. The cylindrical sintered body according to claim 7, wherein the holes observed on the inner side surface of the cylinder are independent at least five positions in the central portion in the direction of the axis of the cylinder, and each has a field of view of 1.176 mm ² Observed holes. A cylindrical sintered body manufactured by the method for manufacturing a cylindrical sintered body according to any one of claims 1 to 4, is a cylindrical sintered body having a length of 470 mm or more along a cylindrical axis direction, and The number of holes observed on the inner surface is 4.25 × 10 ^-5 holes / μm ² or less on average. The cylindrical sintered body according to claim 9, wherein the holes observed on the inner side surface of the cylinder are at least five positions each having a field of view of 1.176 mm ² at the center of the central portion in the direction of the axis of the cylinder. Observed holes. A sputtering target includes the cylindrical sintered body according to any one of claims 6 to 10, and a substrate disposed in a hollow portion inside the cylinder.