JPWO2017195311A1 - Cylindrical sputtering target material firing apparatus and firing method - Google Patents

Abstract

The present invention provides a firing apparatus for producing a long cylindrical sputtering target used when a transparent conductive film used for a liquid crystal display element, a solar cell, or the like is produced by a sputtering method. A fixed hearth on which a fired body of a long cylindrical sputtering target material is placed in an upright state, a fixed hearth placed around the fixed hearth, and a plurality of stages of heaters and oxygen on the inner wall surface of the furnace A firing furnace body provided with an inlet, and the firing furnace body are placed on a traveling carriage, the firing furnace body enables trajectory travel between the firing position and the retracted position, and the lower part of the firing furnace A mechanism for opening and closing the furnace seal is provided between the fixed hearth.

Description

  The present invention relates to a cylindrical sputtering target material firing apparatus, and more particularly, to produce a long cylindrical sputtering target used when a transparent conductive film used for a liquid crystal display element, a solar battery, or the like is manufactured by a sputtering method. The present invention relates to a firing apparatus for an oxide fired body.

  The transparent conductive film is used for liquid crystal display elements, solar cells, and other various light receiving element electrodes because of its high conductivity and high transmittance in the visible light region. As a transparent conductive film, a film having high transmittance and low resistance can be obtained. Therefore, a tin oxide-indium oxide film (ITO film), an aluminum oxide-zinc oxide film (AZO film), an indium oxide-gallium oxide-zinc oxide film. A system film (IGZO film) is widely used.

  A sputtering method is used as a method for producing a transparent conductive film made of such an oxide film. In the sputtering method, 100% argon gas of about 10 Pa or less is generally introduced, a sputtering target that is a raw material of the film is set on the cathode, and argon plasma is generated in a state where the substrate is set parallel to the target, Particles of the target component that are blown off when the argon cation collides with the target are deposited on the substrate to form a film. At present, in order to increase the film formation rate in the sputtering method, magnetron sputtering is employed in which sputtering is performed while applying a magnetic field to the cathode.

  When a flat sputtering target is used for this sputtering target, in the magnetron sputtering method, plasma concentrates on a specific portion of the flat sputtering target material due to a magnetic field, and erosion occurs, and the deepest part of the erosion reaches the backing plate. As a result, there was a problem that the use efficiency of the target remained at 20 to 30%.

  In order to cope with this problem, a cylindrical sputtering target is adopted, a magnetic field generating facility and a cooling facility are installed inside the cylindrical backing tube, and sputtering is performed while rotating the cylindrical sputtering target. As a result, the target The use efficiency can be increased to 60 to 70%. One method for producing this cylindrical sputtering target is a sintering method.

  In the sintering method, water, a binder, and a dispersant are added to the raw material oxide powder and mixed to form a slurry, which is granulated with a spray dryer, etc., and then subjected to cylindrical sputtering with a cold isostatic press (CIP method). In this method, the target is molded, and the resulting molded body is fired and molded at normal pressure in a high-temperature atmosphere in which an oxygen-containing gas flows, and a high-density target having a relative density of 90% or more can be produced.

  However, when a cylindrical sputtering target is formed by a sintering method, there is a problem that cracks, cracks, deformation, warpage, and fine cracks are generated in the sintered body during firing of the oxide sintered body. In addition, in the sputtering method, in order to obtain a film having stable and uniform characteristics with a uniform film thickness, it is desirable to make the density, crystal grain size, and bulk resistance of the oxide sintered body uniform.

  In order to solve this problem, the density is high, the bulk uniformity is high, and defects such as cracks, cracks and deformation are suppressed not only during firing but also in the manufacturing process and sputtering of a cylindrical sputtering target after firing. Prior art for obtaining a quality oxide sintered body for a cylindrical sputtering target is disclosed.

JP 2012-1265887 A ([0019-0021], [0024-0026], [FIG. 1])

  The prior art is a rectangular electric furnace having a cylindrical sputtering target molded body having a size of 15 cm diameter × 20 cm length to 20 cm diameter × 30 cm length, and is directed upward from below in the furnace. When the atmospheric gas such as oxygen gas is circulated, the flow of oxygen-containing gas is uneven in the height direction in the furnace and inside and outside of the molded body, and the furnace temperature distribution is uneven. A uniform atmosphere over the height direction of the cylindrical molded body and between the outside and inside by adjusting the position and number of pipes for supplying the atmosphere gas. The gas flow is made, the furnace temperature distribution is made uniform, and the sintering proceeds uniformly. As a result, a highly uniform cylindrical oxide sintered body can be obtained.

  On the other hand, the cylindrical sputtering target obtained by the prior art has a length of 20 to 30 cm, and in order to produce a 1.5 to 3 m long cylindrical sputtering target using this, 5 to 10 pieces are used. Although it is necessary to stack the targets, bonding between the targets is performed by bonding. However, it is said that the generation of arcing and particles cannot be suppressed unless the level difference of the divided portion which is the bonding is 0.5 mm or less. Therefore, when the number of divisions is increased, the number of occurrences of arcing is increased, cracking due to the divided portions is likely to occur, and there is a problem in that it takes time and labor for bonding, resulting in poor production efficiency.

  In order to solve this problem, it is required to manufacture and use as long a cylindrical sputtering target as possible, and as one of them, firing of a long cylindrical sputtering target material is achieved with appropriate quality. There has been a need to be able to do it. For firing conventional flat sputtering target materials and short cylindrical sputtering target materials, a firing furnace having a low furnace height has been used. These firing furnaces are of a type in which a plate-like or short cylindrical sputtering target material, which is an object to be fired, is carried into the furnace and transferred into the furnace for firing. When this furnace is applied to firing a long cylindrical sputtering target material, when carrying a long object to be fired into the furnace, it is necessary to completely prevent falling and tilting. It was not achieved, and in the worst case, it could fall down and be damaged.

  The present invention solves these problems, and when firing a plurality of long cylindrical sputtering target materials standing up and firing, without destroying the long fired object, It is an object of the present invention to provide a firing apparatus and a firing method that can be fired with less quality variation in the height and radial direction.

In order to achieve the above object, a firing apparatus for a cylindrical sputtering target material according to claim 1 of the present invention is a firing apparatus for a long cylindrical sputtering target material having a length of 1.5 to 2 m. A fixed hearth on which the sintered body of the long cylindrical sputtering target material is placed in an upright state, and a plurality of heaters disposed on the inner wall surface of the furnace. The firing furnace body provided and the firing furnace body placed on a traveling carriage, the firing that enables the rail travel to a position where the firing furnace body is separated from the position containing the fixed hearth and retracted A furnace traveling device, and a furnace shell door that is openable and closable so as not to interfere when the fixed hearth is included is provided on one side surface of the firing furnace main body, and a lower part of the furnace shell and the fixed furnace Air leakage prevention between the floor edge Lumpur portion is provided, at the time of firing is characterized in that a furnace sealing lifting device for sealing by pressure contact seal portion by downward moving the sintering furnace main body.

  The cylindrical sputtering target material according to the present invention is a long cylindrical sputtering target material having a diameter of 150 to 300 mm, a thickness of around 10 mm, and a length of 1.5 to 2 m. This baking is performed at a high temperature of 1250 to 1700 ° C. for 3 to 30 hours in an oxygen atmosphere. By adopting the configuration of claim 1, when firing a plurality of the long cylindrical sputtering target materials, the firing furnace main body and the traveling device are separated from the retracted position. The operation | work which mounts in an appropriate position on a fixed hearth can be performed reliably. In addition, the firing furnace body travels to the firing position and surrounds the fixed hearth, but the furnace shell door of the firing furnace is fully opened so that it travels without damaging the cylindrical sputtering target material. And can be fired. Also, at the firing position, a furnace seal elevating device that prevents the gap between the firing furnace main body and the fixed hearth can be provided, and the seal between the inside of the furnace and the outside of the furnace can be performed completely. It is possible to appropriately maintain a high firing temperature. Thus, a long cylindrical sputtering target having a uniform and appropriate quality can be obtained by firing.

  A cylindrical sputtering target material firing apparatus according to claim 2 is the cylindrical sputtering target material firing apparatus according to claim 1, wherein the furnace seal lifting device supports a furnace at a lower portion of the firing furnace body. The four support beams and the geared reduction device connected to the four support beams are provided, and each geared reduction device is driven from a single lifting / lowering geared motor through a driving force distribution device.

According to this configuration, the geared reduction device is provided at four locations around the firing furnace, and the rotational force of one drive geared motor can be properly divided into four to apply the reduction of the seal portion. Sealing between the fixed hearths is performed appropriately and evenly, and the high-temperature furnace temperature can be appropriately maintained without being disturbed by air leakage.

Further, the cylindrical sputtering target material firing apparatus according to claim 3 is the cylindrical sputtering target material firing apparatus according to claim 1 or 2, wherein a heater provided on the inner wall surface of the firing furnace includes an inner wall of each furnace. It is characterized by being arranged in three or more stages in the height direction.

Further, the cylindrical sputtering target material firing apparatus according to claim 4 is the cylindrical sputtering target material firing apparatus according to claim 3, wherein the heater is a U-shaped ceramic heater made of MoSi _2. Features.

A cylindrical sputtering target material firing apparatus according to claim 5 is the cylindrical sputtering target material firing apparatus according to claim 3 or 4, wherein the heater is paired with an in-furnace thermometer. It is characterized by having installed.

With these configurations, the distribution of the firing temperature in the height direction in the firing furnace can be adjusted uniformly. Specifically, it is possible to control the temperature to a predetermined temperature by measuring the temperature of the area divided in the height direction with a thermometer installed therein and increasing or decreasing the heat output of the heater in the area. Normally, the tendency that the temperature in the furnace becomes higher at the higher temperature than at the lower temperature can be made to approach the predetermined temperature uniformly by adjusting the heat output for each zone. Thereby, there is no variation in the firing degree in the height (length) direction of the long cylindrical sputtering target material, which contributes to stable quality.

In addition, because the MoSi ₂ U-shaped ceramic heater is used as the heater, it has sufficient heat resistance and oxidation resistance at a maximum firing temperature of around 1700 ° C in an oxygen atmosphere, has a long life, and exhibits sufficient heating capacity. Therefore, it is optimal for firing a cylindrical sputtering target material that is fired for a long time. In addition, because the shape of the heater is U-shaped, it has a shape that can withstand the thermal expansion and contraction associated with the temperature rise and cooling of the heater, as well as each fractionated area divided in the height direction and the peripheral direction. This heater has an optimum shape in terms of heating strength and heating density. In addition, since the heater and the thermometer are arranged as a pair for each area, the temperature control for each of the divided areas in the height direction and the peripheral direction can be performed accurately and accurately.

Moreover, the cylindrical sputtering target material firing apparatus according to claim 6 is the cylindrical sputtering target material firing apparatus according to any one of claims 1 to 5, wherein the firing furnace main body has one or more upper portions. A gas discharge hole is provided, and a plurality of oxygen blowing holes are provided in the height direction / periphery direction on the furnace inner wall from the lower part of the cylindrical sputtering target material on which the fixed hearth is placed.

By adopting this configuration, the flow of oxygen in the firing furnace can be made uniform in the cross-sectional direction, and the difference in oxygen concentration at each location is minimized. As a result, the furnace temperature distribution and the oxygen concentration distribution can be made uniform, so that the firing of the long cylindrical sputtering target material that is the object to be fired can proceed almost completely homogeneously, and the relative density can be stabilized. In addition, the variation in relative density in the length direction and the cross-sectional direction can be substantially eliminated.

Moreover, the baking method of the cylindrical sputtering target material of Claim 7 uses the baking apparatus of the cylindrical sputtering target material in any one of Claims 1-6, and is a long thing 1.5-2 m in length. One or a plurality of cylindrical sputtering target materials to be fired are placed on a fixed hearth in a state where they are self-supporting at predetermined intervals, and then the fixed hearth is taken into the center of the furnace. After the furnace shell door is opened and the firing furnace is moved from the retracted position to the firing position, the furnace shell door is closed and the temperature of the firing furnace is increased to a high temperature of 1250 to 1700 ° C. in an oxygen atmosphere. And firing a material to be fired for 3 to 30 hours to obtain a cylindrical sputtering target.

The cylindrical sputtering target material firing method according to claim 8 is the cylindrical sputtering target material firing method according to claim 7, wherein the cylindrical sputtering target material is an ITO (tin oxide-indium oxide system) material, AZO ( It is characterized by being an aluminum oxide-zinc oxide system material or an IGZO (indium oxide-gallium oxide-zinc oxide system) material.

The cylindrical sputtering target material according to the present invention is a long cylindrical sputtering target material having a diameter of 150 to 300 mm, a thickness of around 10 mm, and a length of 1.5 to 2 m. This firing is performed with an ITO material at a high temperature of 1450 to 1700 ° C., preferably at a high temperature of 1500 to 1600 ° C., and with an AZO or IGZO material at a high temperature of 1250 to 1500 ° C., preferably at a temperature of The reaction is performed at a high temperature of 1300 to 1450 ° C. in an oxygen atmosphere for 3 to 30 hours, preferably 5 to 10 hours. If this time is too long, the sintered structure may be enlarged and easily cracked. The rate of temperature rise to the target firing temperature in firing is 100 to 500 ° C./Hr, and the rate of temperature decrease from the target firing temperature is 10 to 150 ° C./Hr.

When firing the above-described cylindrical sputtering target material, by using the above-mentioned cylindrical sputtering target material firing apparatus, it is possible to place a long cylindrical sputtering target material on the fixed hearth in a stable posture, There is no risk of damaging the cylindrical sputtering target material during the mounting operation. Moreover, since the main firing furnace is used, an appropriate firing temperature and its distribution can be easily given by controlling the oxygen atmosphere, so that the same firing temperature can be uniformly applied in the entire length direction of the object to be fired. In addition, it is possible to obtain a stable cylindrical sputtering target having high surface properties and relative density without cracks.

According to the firing apparatus and firing method for a cylindrical sputtering target material according to claims 1 to 8 of the present invention, the cylindrical sputtering target material, which is an object to be fired, is placed on the fixed hearth during the firing operation. Instead, the firing furnace moves from the standby position to the firing position to perform firing, so that the object to be fired is tilted by movement and the distance from the heating source does not change, and there is a risk of damage due to movement. No, the firing quality of the object to be fired can be obtained stably. In addition, heating from the furnace wall from four directions is installed by dividing the heater in the height direction, making it easy to adjust the temperature distribution in the furnace height direction to be a long cylindrical sputtering target. Contributes to stable and improved firing quality. In addition, the number and position of oxygen inflow and outflow for adjusting the oxygen atmosphere are arranged so that a uniform flow can be obtained with respect to the object to be fired. In combination, the oxygen concentration and the firing temperature can be stably applied to the long cylindrical sputtering target material as intended.

As described above, according to the firing apparatus and firing method of the cylindrical sputtering target material of the present invention, it is easy to make a long cylindrical sputtering target corresponding to the target quality, and the equipment is not excessive. In addition, the baking apparatus is configured by compactly integrating facilities that have been used, has a small installation area, does not have a large facility cost, and is environmentally superior with no air pollution. In addition, since a 1.5 to 2 m long cylindrical sputtering target can be easily produced with high quality, this is used to manufacture a transparent conductive film of a large liquid crystal display device or a large photovoltaic power generation device. An optimum sputtering target with high use efficiency can be provided.

FIG. 1 is a schematic layout diagram of a firing apparatus for a cylindrical sputtering target material according to an embodiment for carrying out the present invention, and is a layout (cross section) diagram at the time of firing. FIG. 2 is an arrangement (cross-sectional) view at the time of saving in FIG. 3 is a schematic cross-sectional view taken along the line AA in FIG. 4 is a schematic cross-sectional view taken along the line BB in FIG.

A firing apparatus 1 (hereinafter referred to as firing apparatus 1) for a cylindrical sputtering target material according to the present invention will be described with reference to FIGS.

  The cylindrical sputtering target material M used in the firing apparatus and firing method for the cylindrical sputtering target material according to the present invention is a long cylindrical sputtering material having a diameter of 150 to 300 mm, a thickness of about 10 mm, and a length of 1.5 to 2 m. Target material. This material is an ITO (tin oxide-indium oxide system) material, an AZO (aluminum oxide-zinc oxide system) material, or an IGZO (indium oxide-gallium oxide-zinc oxide system) material. This firing is in the case of ITO material at a high temperature of 1450-1700 ° C, preferably at a high temperature of 1500-1600 ° C, and in the case of AZO or IGZO material at a high temperature of 1250-1500 ° C, Preferably, it is performed at a high temperature of 1300 to 1450 ° C. for 3 to 30 hours, preferably 5 to 10 hours in an oxygen atmosphere. The temperature rising rate in firing is 100 to 500 ° C./Hr, and the temperature decreasing rate is 10 to 150 ° C./Hr.

  FIG. 1 is a schematic plan view of the firing apparatus 1 and shows the layout during firing. A firing furnace main body 2 that takes in a fixed hearth 3 on which four of the objects M to be fired, which are cylindrical sputtering target materials, are placed in a standing state is loaded on the firing furnace traveling device 4 and travels. The vehicle can run on the rail 4-3. At the time of firing, the firing furnace main body 2 has three faces of the furnace shell 2-c and the furnace wall refractory 2-a so as to surround the fixed hearth 3 from the four sides under the center, and the remaining one face can be opened and closed. There is an open / close door 2-2 lined with a refractory 2-a, and although not shown, there is a furnace refractory 2-b at the top of the furnace, and thus the inside of the firing furnace body 2 is refractory. Lined with objects. As the refractory, a high-temperature and oxidation-resistant regular or irregular refractory material such as alumina or magnesia is used, and a conventional heat insulation is used on the furnace shell side. Further, as shown in FIGS. 3 and 4, the fixed hearth 3 is a quadrangular prism-shaped refractory, and a high-temperature and oxidation-resistant regular or irregular refractory material such as alumina and magnesia is used. . In addition, when placing the object to be fired M on the fixed hearth 3, the firing temperature at the lower end of the object to be fired M can be maintained by inserting the placing table 3-a between them, and the firing quality is maintained. easy. As the mounting table 3-a, a refractory having the same properties as the fixed hearth 3 is preferably used.

  FIG. 2 shows that the firing furnace body 2 of the firing apparatus 1 has moved from the fixed hearth 3 to a standby position. In this case, the fixed hearth 3 is in an uncovered state, in which the object to be fired M is loaded or placed, or the fired object M to be fired is taken out, and there are no obstacles around the work. Therefore, the operation can be easily and reliably performed. On the other hand, the firing furnace main body 2 has the open / close door 2-2 fully open, and can be easily moved away from the fixed hearth 3 without hindrance. Further, when moving the firing furnace body 2, it is necessary to operate the furnace seal lifting device 5 to release the furnace seal.

Next, the firing furnace traveling device 4 will be described with reference to FIGS. 3 and 4. The firing furnace body 2 is mounted on the traveling carriage 4-4 via the four support beams 5-5. The traveling carriage 4-4 includes a total of four traveling wheels 4-2 mounted on two traveling rails 4-3, and one of the traveling wheels 4-2 on one side is rotationally driven by a drive geared motor 4-1. Although not shown, the traveling carriage 4-4 can automatically travel between a predetermined distance by a proximity switch corresponding to the firing position and the retreat position of the firing furnace body 2 provided on the traveling rail 4-3. .

Next, the furnace seal between the firing furnace body 2 and the fixed hearth 3 will be described based on FIGS. 1, 3, and 4. The firing furnace body 2 travels to the firing position in FIG. 1, When the fixed hearth 3 is stopped in the state of being taken into the furnace, and then the door 2-2 is closed, as shown in FIGS. 3 and 4, the lower portion of the firing furnace body 2 and the outer peripheral portion of the fixed hearth 3 are separated. A step-like gap is provided between them. The furnace seal is completed by closing the firing furnace body 2 by closing the gap. By establishing this furnace seal, it is possible to completely prevent the outside air from entering the furnace through the seal portion, or the oxygen atmosphere gas in the furnace from leaking outside the furnace, and to disturb the firing temperature. To prevent becoming.

As described above, the firing furnace body 2 is placed on the traveling carriage 4-4 via the support beam 5-5 and the geared reduction device 5-4. The furnace seal elevating device 5 includes a single drive geared motor 5-1, a drive shaft 2, two drive force distribution devices 5-3, and four geared reduction devices 5-4. The output of one drive geared motor 5-1 is first distributed to the output shaft 5-2 orthogonal to the main shaft 5-2 by one drive force distribution device 5-3, and one output shaft 5-2 Connected to two geared reduction devices 5-4. Another orthogonal output shaft 5-2 is connected to the two geared reduction devices 5-4 via the orthogonal output shaft 5-2 by the driving force distribution device 5-3. Thus, in synchronization with the output of one drive geared motor 5-1, the four geared reduction devices 5-4 are connected to the support beams 5-5 to move the firing furnace main body 2 up and down, and firing. Implementation and cancellation of the furnace seal between the furnace body 2 and the fixed hearth 3 can be performed.

As shown in FIGS. 1, 2, and 3, the open / close door 2-2 attached to the firing furnace body 2 is provided on the entire furnace side surface opposite to the retracting movement direction of the firing furnace body 2. The open / close door 2-2 has a single-open structure that revolves around an open / close shaft 2-2a attached to the furnace shell so that it does not interfere with the fixed hearth 3 when the firing furnace body 2 moves. Can be fully opened. The furnace inner wall of the open / close door 2-2 is provided with a door refractory 2-2c, and further protrudes from the door refractory 2-2c, and the heater 2-d and the furnace temperature over four stages in the height direction. A total of 2-e is provided. The opening / closing of the open / close door 2-2 can be performed manually or automatically. However, in the case of automatic, it is necessary to interlock the position information of the firing furnace body 2 and the fixed hearth 3.

The firing furnace body 2 will be described with reference to FIGS. The firing furnace main body 2 bakes a long cylindrical sputtering target material with a length of 150 to 300 mm × 1.5 to 2 m in an oxygen atmosphere at a set temperature in the range of 1250 to 1700 ° C. for 3 to 30 hours. Used as a firing furnace. In the present embodiment, the in-furnace dimensions of the firing furnace body 2 are approximately 1.1 m square × 2.2 m height. In this figure, an embodiment in which four long objects to be fired are described. However, the present invention is not restricted by this number, and can uniformly apply radiation and convection heat transfer to the objects to be fired. The present invention is applicable as long as it has an array of 2 × N columns. In addition, it is desirable to bake an object to be fired having the same long length because the same baking quality is easily obtained.

The firing furnace body 2 has three sides of the furnace shell 2-c on the side surface, and the remaining one surface is constituted by an open / close door 2-2. The furnace inner sides of the furnace shell 2-c and the open / close door 2-2 are lined with a furnace wall refractory 2-a and a door refractory 2-2c, respectively. The inner wall of the ceiling portion of the firing furnace body 2 is made of a furnace ceiling refractory 2-b. As the refractory, a high-temperature and oxidation-resistant regular or irregular refractory material such as alumina or magnesia is used, and a conventional heat insulation is used on the furnace shell side.

As shown in FIGS. 3 and 4, the heater 2-d is provided with a terminal portion in the furnace shell 2-c and the like, and penetrates the furnace wall refractory 2-a and the door refractory 2-2c. The heater part is provided in a form protruding from the furnace inner surface. The heater 2-d is provided in four stages in the furnace height direction. The heater 2-d is preferably a U-shaped ceramic heater made of MoSi ₂ and has sufficient heat resistance and oxidation resistance at a maximum firing temperature of about 1700 ° C. in an oxygen atmosphere, has a long life, and exhibits sufficient heating capability. Therefore, it is optimal for firing the cylindrical sputtering target material M that is fired for a long time. Moreover, since the shape of the heater 2-d is U-shaped, the heater 2-d has a shape that can withstand thermal expansion and contraction caused by temperature rise and cooling of the heater 2-d, and is divided in the height direction and the peripheral direction As the heater 2-d for each fractionated area, it has an optimum shape in terms of heating strength and heating density.

A furnace thermometer 2-e is inserted from the furnace shell 2-c into the furnace at the center of each stage of the heater 2-d, and is disposed in pairs with the heater 2-d. The internal temperature can be measured. Thereby, distribution of the baking temperature of the height direction in the furnace of the baking furnace main body 2 can be adjusted uniformly. Specifically, the temperature of the section divided in the height direction is measured by the in-furnace thermometer 2-e, and the heat output of the heater 2-d in the section is increased or decreased. Can be controlled to a predetermined temperature. Normally, the tendency that the temperature in the furnace becomes higher at the higher temperature than at the lower temperature can be made to approach the predetermined temperature uniformly by adjusting the heat output for each zone. As a result, there is no variation in the firing degree in the height (length) direction of the long cylindrical sputtering target material M, which contributes to stable quality. As the in-furnace thermometer 2-e, a well-known platinum rhodium thermocouple can be used.

As shown in FIGS. 3 and 4, one or a plurality of gas discharge holes 2-are formed in the upper part of the firing furnace body 2 so that the inside of the firing furnace body 2 is maintained in an oxygen atmosphere and the firing temperature is kept at a specified level. g and a plurality of oxygen blowing holes in the height direction / periphery direction from the lower part of the cylindrical sputtering target material M on which the fixed hearth is placed and from the furnace inner walls 2-b, 2-2-2c ( (Not shown). With this configuration, the flow of oxygen in the firing furnace main body 2 can be made uniform in the cross-sectional direction, and the difference in oxygen concentration at each location is minimized. As a result, the furnace temperature distribution and the oxygen concentration distribution can be made uniform, so that the firing of the long cylindrical sputtering target material M, which is an object to be fired, can proceed almost completely homogeneously, and the relative density can be increased. While improving stably, the variation of the relative density of a length direction or a cross-sectional direction can be substantially eliminated.

A firing method using the cylindrical sputtering target material firing apparatus according to the present invention will be described with reference to FIGS. As the cylindrical sputtering target material, a material selected from an ITO (tin oxide-indium oxide system) material, an AZO (aluminum oxide-zinc oxide system) material, or an IGZO (indium oxide-gallium oxide-zinc oxide system) material can be used. . The cylindrical sputtering target material is prepared by adding water, a binder and a dispersant to the raw material oxide powder, mixing it into a slurry, granulating it with a spray dryer, etc., and then cold isostatic pressing (CIP method), etc. Can be molded and manufactured. The cylindrical sputtering target material is a long cylindrical sputtering target material having a diameter of 150 to 300 mm, a thickness of around 10 mm, and a length of 1.5 to 2 m.

The firing method of the cylindrical sputtering target material is performed as follows. A fixed furnace in which a single or a plurality (four in the figure) of objects to be fired of a cylindrical sputtering target material M having a length in the range of 1.5 to 2 m are self-supported at predetermined intervals. The open / close door 2-2 of the firing furnace body 2 was opened so that the fixed furnace floor 3 was taken into the center of the furnace, and the firing furnace body 2 traveled from the retracted position to the firing position. Thereafter, the door 2-2 is closed, the temperature of the firing furnace body 2 is increased, and the object to be baked M is baked at a high temperature of 1250 to 1700 ° C. in an oxygen atmosphere for 3 to 30 hours. A shaped sputtering target can be obtained.

This firing is performed with an ITO material at a high temperature of 1450 to 1700 ° C., preferably at a high temperature of 1500 to 1600 ° C., and with an AZO or IGZO material at a high temperature of 1250 to 1500 ° C., preferably at a temperature of The reaction is performed at a high temperature of 1300 to 1450 ° C. in an oxygen atmosphere for 3 to 30 hours, preferably 5 to 10 hours. If this time is too long, the sintered structure may be enlarged and easily cracked. The rate of temperature rise to the target firing temperature in the firing process is 100 to 500 ° C./Hr, and the rate of temperature decrease after the firing is 10 to 150 ° C./Hr.

The sintered cylindrical sputtering target is bonded to a backing tube with a built-in magnetic field generation facility and cooling facility by bonding, magnetron sputtering is performed, and the target oxide is deposited on the substrate by this sputtering. And a transparent conductive film used for solar cells and the like can be reliably and stably manufactured.

Not only can it be used in the field of firing cylindrical sputtering target materials, it can also be applied in the field of high-temperature firing treatment in an oxidizing and reducing atmosphere of long objects.

1: Cylindrical sputtering target material firing device
2: Firing furnace main body 2-a: Furnace wall refractory 2-b: Furnace ceiling refractory 2-c: Furnace shell 2-d: Heater 2-e: In-furnace thermometer
2-f: Oxygen inlet 2-g: Oxygen outlet 2-2: Open / close door
2-2a: Opening and closing shaft 2-2b: Closing handle 2-2c: Door refractory 3: Fixed hearth 3-a: Mounting table 4: Firing furnace traveling device 4-1: Drive geared motor 4-2: Traveling wheel 4-3: Traveling rail 4-4: Traveling cart 5: Furnace seal lifting device 5-1 Drive geared motor 5-2: Drive shaft 5-3: Driving force distribution device 5-4: Geared pressure reduction Apparatus 5-5: Support beam M: Object to be fired (cylindrical sputtering target material)

Claims (8)

A firing apparatus for a long cylindrical sputtering target material having a length of 1.5 to 2 m, and a fixed hearth on which the fired body of the long cylindrical sputtering target material is placed in an upright state; A firing furnace body disposed to contain the fixed hearth and having a plurality of heaters provided on a wall surface of the furnace, and the firing furnace body is placed on a traveling carriage, the firing furnace body A firing furnace traveling device that enables rail travel to a position away from a position including the fixed hearth and retracting, and interfering when the fixed hearth is included on one side of the firing furnace body. In addition to providing a furnace shell door that can be opened and closed, a seal part for preventing leakage is provided between the bottom of the furnace shell and the peripheral edge of the fixed hearth, and the firing furnace body is moved downward during firing. Seal the seal part tightly under pressure Baking apparatus the cylindrical sputtering target material, characterized in that a sealing lifting device. The furnace seal elevating device includes four supporting beams for supporting the furnace at the lower part of the firing furnace body and a geared pressure reducing device connected to the support beam, and each geared pressure reducing device from a single elevating geared motor through a drive distributor. The apparatus for firing a cylindrical sputtering target material according to claim 1, wherein the apparatus is driven. The cylindrical sputtering target according to claim 1 or 2, wherein the heater provided on the inner wall surface of the firing furnace is divided into three or more stages in the height direction of each inner wall of the furnace. Material firing equipment. The heater is calciner cylindrical sputtering target material according to claim 3, characterized in that the U-shaped ceramic heater made of MoSi _2. 5. The cylindrical sputtering target material firing apparatus according to claim 3, wherein the heater is disposed in a pair with a furnace thermometer. 6. The firing furnace main body has one or a plurality of gas discharge holes in the upper part, and a plurality of oxygen in the height direction / periphery direction from the lower part of the cylindrical sputtering target material on which the fixed hearth is placed and on the inner wall of the furnace. The firing apparatus for a cylindrical sputtering target material according to any one of claims 1 to 5, wherein a blowing hole is provided. Using the cylindrical sputtering target material firing apparatus according to any one of claims 1 to 6, a single or a plurality of cylindrical sputtering target materials to be fired having a length of 1.5 to 2 m. Place it on the fixed hearth in a state of being self-supported at a predetermined interval, then open the furnace shell door so that the fixed hearth is taken into the center of the furnace, and the firing furnace from the retracted position to the firing position The furnace shell door is closed, the firing furnace is closed, the firing furnace is heated, and the fired article is fired at a high temperature of 1250 to 1700 ° C. for 3 to 30 hours in an oxygen atmosphere to form a cylindrical shape. A method for firing a cylindrical sputtering target material, comprising obtaining a sputtering target. The cylindrical sputtering target material is an ITO (tin oxide-indium oxide system) material, an AZO (aluminum oxide-zinc oxide system) material, or an IGZO (indium oxide-gallium oxide-zinc oxide system) material. 8. A method for firing a cylindrical sputtering target material according to item 7.

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