JP6053977B2 - Cylindrical sputtering target - Google Patents

Description

  One embodiment of the present invention relates to a sputtering target, and relates to a sputtering target in which a target material and a substrate are bonded by a bonding material made of a metal material.

  A sputtering target material used for forming a thin film by sputtering is attached to a sputtering apparatus in a state of being stretched around a base material that supports the sputtering target material. A typical sputtering target has a form in which a target material formed into a plate shape is bonded to a plate-like support base material (also referred to as a “backing plate”).

  The sputtering target mounted on the sputtering apparatus is held under reduced pressure during film formation by sputtering, and is sputtered by irradiation with ions generated in glow discharge plasma using argon gas or the like. Since the temperature of the target material rises when irradiated with ions, the sputtering apparatus is provided with a sputtering target cooling mechanism. As the cooling mechanism, many are used that are configured such that cooling water flows on the back side of the supporting base material.

  Since the target material and the support base material are usually different from each other, a bonding material is used to bond the two. As the bonding material, a metal material having a relatively low melting point such as indium or tin is used.

  The magnetron sputtering method is the mainstream in the thin film production technology by sputtering. Since the flat type sputtering target used for the magnetron sputtering apparatus has a narrow erosion region where the target material is consumed by sputtering, the effective usage rate of the target material is said to be about 20% to 30%. On the other hand, a cylindrical sputtering target having a cylindrical target material has been developed.

  The cylindrical sputtering target has a structure in which a cylindrical target material is mounted on the outer peripheral surface of a cylindrical base material. By performing sputtering film formation while rotating such a cylindrical sputtering target, the erosion region where the target material is consumed is expanded, and the usage rate of the target material is improved (for example, see Patent Document 1).

JP 2010-018883 A

  In the sputtering target, the target material and the base material are bonded together with a bonding material. At this time, if the bonding material provided between the target material and the base material is not uniformly filled and voids are formed, the bonding strength is lowered. In addition, if there are voids in the bonding material, the heat of the target material is less likely to diffuse through the base material at the part, so that there is a possibility that the target material is damaged due to thermal strain.

  A cylindrical sputtering target has a structure in which a gap is provided between a cylindrical substrate and a cylindrical sputtering target material arranged coaxially therewith, and this gap is filled with a bonding material to fix both. Have. If the bonding material does not fill well in the gap between the cylindrical base material and the cylindrical sputtering target material and a gap is formed, bonding will be defective, and the cylindrical sputtering target material may idle or be distorted during sputtering film formation. This causes a problem of cracking.

  In the cylindrical sputtering target described in Patent Document 1, after filling with a bonding material, cooling is started from one end in the cylindrical axis direction, sequentially cooled toward the other end, and a molten bonding material is further supplied during cooling. By doing so, it is described that the ratio of voids can be reduced to a certain level.

  Flat plate sputtering targets are used in a stationary state when mounted in a sputtering apparatus, but cylindrical sputtering targets are used by rotating themselves, so that the bonding material has a bonding strength that can withstand it. Required. In addition, since the cylindrical sputtering target material is uniaxially held by the cylindrical base material, it is held so that the target material is not easily broken even when subjected to bending due to its own weight or thermal or mechanical distortion. Need to be. However, there is a problem that these requirements cannot be satisfied simply by filling the bonding material so that there is no gap between the cylindrical base material and the cylindrical sputtering target material.

  In view of such problems, it is an object of the present invention to provide a cylindrical sputtering target that prevents cracking of the cylindrical sputtering target material and is stably held on the cylindrical base material.

  According to one embodiment of the present invention, there is provided a base material made of metal, a sputtering target material provided on one surface of the base material, and a bonding material provided between the base material and the sputtering target material. The bonding material includes at least a first metal element and a second metal element, and the second metal element is provided at a concentration of 10 ppm to 5000 ppm with respect to the first metal element. The

  According to one embodiment of the present invention, a cylindrical substrate formed of metal, a cylindrical sputtering target material provided coaxially on the outer peripheral surface of the cylindrical substrate, a cylindrical substrate and a cylindrical sputtering target A bonding material provided between the first metal element and the bonding material. The bonding material includes at least a first metal element and a second metal element, and the second metal element is 10 ppm relative to the first metal element. Thus, a sputtering target contained at a concentration of 5000 ppm or less is provided.

  In one embodiment of the present invention, the first metal element is indium (In), and the second metal element is one selected from copper (Cu), titanium (Ti), and nickel (Ni). Is preferred.

  In one embodiment of the present invention, the first metal element is indium (In), the second metal element is copper (Cu), and the copper (Cu) as the second metal element is the first metal. It is preferably contained at a concentration of 2000 ppm or more and 5000 ppm or less with respect to indium (In) as an element.

  In one embodiment of the present invention, the first metal element is indium (In), the second metal element is titanium (Ti), and titanium (Ti) as the second metal element is the first metal. It is preferably contained at a concentration of 18 ppm or more and 120 ppm or less with respect to indium (In) as an element.

  In one embodiment of the present invention, the first metal element is indium (In), the second metal element is nickel (Ni), and nickel (Ni) as the second metal element is the first metal. It is preferably contained at a concentration of 44 ppm or more and 480 ppm or less with respect to indium (In) as an element.

  The bonding material may have a Shore hardness of 1.1 or more and 1.7 or less, and a contact angle with respect to the ITO surface may be 15 ° or more and less than 25 °.

  The sputtering target material is a ceramic sintered body. For example, the ceramic sintered body may contain indium oxide. The outer surface of the substrate may have a surface roughness (Ra) value of 1.8 μm or more.

  According to one embodiment of the present invention, at least a first metal element and a second metal element are included for joining the sputtering target material and the base material, and the second metal element is relative to the first metal element. By using a bonding material contained at a concentration of 1% or less, it is possible to prevent the sputtering target material from cracking and obtain a sputtering target that is stably held on the substrate.

It is a perspective view which shows the structure of the cylindrical sputtering target which concerns on one Embodiment of this invention. It is a cross section which shows the structure of the cylindrical sputtering target which concerns on one Embodiment of this invention. It is sectional drawing explaining the manufacturing method of the cylindrical sputtering target which concerns on one Embodiment of this invention. It is a figure which shows the method of evaluating the wettability of a joining material.

  Embodiments of the present invention will be described below with reference to the drawings. However, the present invention can be implemented in many different modes and should not be construed as being limited to the description of the embodiments exemplified below. In addition, the drawings may be schematically represented with respect to the width, thickness, shape, and the like of each part in comparison with actual aspects for the sake of clarity of explanation, but are merely examples, and the interpretation of the present invention is not limited. It is not limited. In addition, in the present specification and each drawing, elements similar to those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description may be omitted as appropriate.

[Cylindrical sputtering target]
FIG. 1 is a perspective view for explaining the configuration of a cylindrical sputtering target according to this embodiment. FIG. 2 is a sectional view showing the configuration of the sputtering target according to the present embodiment.

  The cylindrical sputtering target 100 includes a cylindrical sputtering target material 102 and a cylindrical base material 104 that supports the cylindrical sputtering target material 102. The cylindrical sputtering target material 102 is fixed to the cylindrical base material 104 by a bonding material 106. The bonding material 106 is provided so as to fill a gap provided between the cylindrical sputtering target material 102 and the cylindrical base material 104.

  The cylindrical sputtering target material 102 is provided so as to surround the outer peripheral surface of the cylindrical base material 104. The cylindrical sputtering target material 102 is preferably provided coaxially or substantially coaxially with the central axis of the cylindrical substrate 104. With such a configuration, when the cylindrical sputtering target is mounted on the sputtering apparatus and rotated around the cylindrical base material 104, the interval between the cylindrical sputtering target material 102 and the film formation surface (sample substrate) is reduced. Can be kept constant.

  In the cylindrical sputtering target 100, a plurality of cylindrical sputtering target materials 102 may be attached to the cylindrical substrate 104. When a plurality of cylindrical sputtering target materials 102 are mounted on the cylindrical base material 104, it is preferable that each cylindrical sputtering target material 102 is disposed with a gap. The gap may be 1 mm or less, for example, 0.2 mm to 0.5 mm. Thus, damage can be prevented by disposing a plurality of cylindrical sputtering target materials 102 with a gap.

  According to the present embodiment, a cylindrical sputtering target having a length of 100 mm or more can be provided by bonding a plurality of cylindrical sputtering target materials 102 to the cylindrical base material 104 with the bonding material 106.

[Cylindrical sputtering target material]
As shown in FIGS. 1 and 2, the cylindrical sputtering target material 102 is formed in a hollow shape and has a cylindrical shape. The cylindrical sputtering target material 102 has a thickness of at least several millimeters to several tens of millimeters, and the entire thick portion can be used as the target material. A cylindrical base material 104 is inserted into a hollow portion of the cylindrical sputtering target material 102 and joined by a joining material 106. The cylindrical sputtering target material 102 and the cylindrical base material 104 are not provided in close contact with each other, but both are arranged with a gap, and a bonding material 106 is provided so as to fill the gap. In order to stably hold the cylindrical sputtering target material 102 and the cylindrical base material 104, the bonding material 106 is preferably provided so that there is no gap in the gap.

  In the cylindrical sputtering target material 102, the outer surface of the cylinder becomes the target surface, and the inner surface of the cylinder faces the cylindrical substrate 104 and comes into contact with the bonding material 106. For this reason, at the time of manufacture, the outer surface of the cylindrical sputtering target material 102 may be molded smoothly, and the inner surface of the cylinder may be roughened in order to improve the adhesion.

  The cylindrical sputtering target material 102 is made of various materials that can be formed by sputtering. For example, the cylindrical sputtering target material 102 may be ceramics. As the ceramic, a metal oxide, a metal nitride, a sintered body of metal oxynitride, or the like can be used. As the metal oxide, an oxide of a metal belonging to a typical element such as indium oxide, tin oxide, zinc oxide, or gallium oxide can be used. Specifically, a sintered body of indium oxide containing tin oxide (Indium Tin Oxide: ITO), a sintered body of zinc oxide (Zinc Oxide: ZnO), indium zinc oxide (IZO), oxidation A sintered body of indium, zinc oxide, gallium oxide (IGZO), or the like can be used as the cylindrical sputtering target material 102. In addition, said illustration is an example and the sputtering target which concerns on this invention can apply various sputtering materials as a target material.

[Cylindrical base material]
The cylindrical substrate 104 preferably has an outer surface shape that follows the inner surface of the cylindrical sputtering target material 102 having a hollow structure. The outer diameter of the cylindrical base material 104 is slightly smaller than the inner diameter of the cylindrical sputtering target material 102, and is adjusted so that a gap is formed when both are coaxially stacked. A bonding material 106 is provided in the gap.

  The cylindrical sputtering target material 102 is heated by irradiation of ions during film formation by sputtering, and the temperature rises. In order to suppress the temperature rise of the cylindrical sputtering target material 102 during sputtering film formation, the cylindrical base material 104 preferably has a cooling function for the cylindrical sputtering target material 102. For example, it is preferable that the cylindrical base material 104 has a hollow structure so that the coolant flows. For this reason, it is preferable that the cylindrical base material 104 has favorable electroconductivity and heat conductivity as a structural member of a sputtering target.

  In addition, the cylindrical base material 104 is preferably a metal that has good wettability with the bonding material and can provide high bonding strength, and is formed of, for example, copper (Cu) or titanium (Ti), or a copper alloy or titanium alloy It is preferable. For example, an alloy mainly composed of copper (Cu) such as chromium copper can be used as the copper alloy. Further, if titanium (Ti) is used as the cylindrical substrate 104, a lightweight and rigid substrate can be obtained.

  The cylindrical substrate 104 is not only formed of a single metal or a metal alloy, but may be one in which a coating of another metal is provided on the surface of the metal substrate. For example, a metal film containing titanium (Ti), copper (Cu), silver (Ag), nickel (Ni), or the like may be formed.

  The cylindrical sputtering target is not irradiated with ions on the entire surface of the cylindrical sputtering target material 102 during sputtering, but rotates while irradiating ions only on a part of the surface. A temperature difference is generated in the cylindrical sputtering target material 102. However, since the cylindrical base material 104 has a cooling function, the temperature rise of the cylindrical sputtering target material 102 on the outer side can be suppressed, and the influence of thermal distortion due to the temperature difference can be suppressed.

  The cylindrical substrate 104 may be roughened on the surface side in contact with the bonding material. By roughening the surface of the cylindrical substrate 104, the surface area in contact with the bonding material can be increased. For example, the surface of the cylindrical substrate 104 may be roughened by sandblasting or the like, and the surface roughness (Ra) may have a value of 1.8 μm or more.

[Bonding material]
The bonding material 106 is provided between the cylindrical sputtering target material 102 and the cylindrical base material 104. The bonding material 106 bonds the cylindrical sputtering target material 102 and the cylindrical base material 104, but besides that, it is required to have good heat resistance and thermal conductivity. In addition, it is required to have a characteristic of low outgassing in a vacuum. Further, from the viewpoint of manufacturing, the bonding material 106 preferably has fluidity when the cylindrical sputtering target material 102 and the cylindrical substrate 104 are bonded. In order to satisfy these characteristics, a low melting point metal material having a melting point of 300 ° C. or lower is used as the bonding material 106. For example, as the bonding material 106, a metal such as indium or tin, or a metal alloy material containing any one of these elements is used. Specifically, indium or tin alone, an alloy of indium and tin, a solder alloy containing tin as a main component, or the like is used as the bonding material 106.

  In the present embodiment, the bonding material 106 includes a plurality of types of metal elements. Among the plurality of types of metal elements, the first metal element is included in the bonding material 106 as a main constituent element, and the second metal element is included at a much lower concentration than the first metal element. Here, a main metal element constituting the bonding material 106 is referred to as a “first metal element”, and a secondary metal element contained in a minute amount than the first metal element is referred to as a “second metal element”. Although the first metal element and the second metal element are not limited to one kind of metal element, the first metal element group and the second metal element group each include a plurality of kinds of metals. There may be one that includes an element.

  In the present embodiment, the first metal element (or first metal element group) included as a main component is a metal element that occupies 99% by weight or more and less than 100% by weight of the first metal element. The second metal element (or the second metal element group) contained at a lower concentration than the metal element is a ratio of 0.001 wt% or more and 0.5 wt% or less (10 ppm or more and 5,000 ppm or less). It is a contained metal element. That is, the second metal element is contained at a concentration of 1/100 or less with respect to the first metal element.

  The inevitably contained impurity element means an element contained at a concentration of 1 ppm or less except for the aforementioned main metal element and trace metal element. In other words, the bonding material 106 contains 0.002 wt% or more and 0.5 wt% or less (10 ppm or more and 5,000 ppm or less) of the second metal element (or the second metal element group). It is contained in a proportion, and the others are composed of the first metal element (or first metal element group) and inevitable impurities.

  In other words, the total of the second metal element (or the second metal element group), the first metal element (or the first metal element group), and inevitably contained impurity elements is 100 weight. In a range not exceeding%, it is preferably contained at a concentration of 0.001 wt% or more and 0.5 wt% or less (10 ppm or more and 5000 ppm or less).

  In the bonding material 106, the first metal element (or first metal element group) included as a main component is preferably the same metal element as the at least one metal element included in the cylindrical sputtering target material 102. . When the bonding material 106 includes the same kind of metal element as the cylindrical sputtering target material 102, for example, in a cylindrical sputtering target in which a plurality of cylindrical sputtering target materials 102 are mounted on the cylindrical substrate 104. Even if the bonding material 106 is exposed in the joint region of the cylindrical sputtering target material 102, it is possible to prevent impurity contamination of the film deposited by sputtering.

  For the bonding material 106, a metal such as indium (In) or tin (Sn) is selected as the first metal element. Since these metals have a melting point of 300 ° C. or lower, they can be poured into the gap 108 between the cylindrical sputtering target material 102 and the cylindrical base material 104 in a molten state. Further, the bonding material 106 may contain both indium (In) and tin (Sn) so as to be grasped as the first metal element group.

  In the case where the cylindrical sputtering target material 102 is a ceramic containing indium oxide, indium can be used as the first metal element contained as a main component in the bonding material 106. When the cylindrical sputtering target material 102 is a ceramic containing indium oxide and tin oxide, indium, tin, or an alloy of indium and tin is used as the first metal element contained as a main component in the bonding material 106. Can do.

  The second metal element contained in the bonding material 106 is a metal element different from the first metal element, and is preferably a transition element, for example. In addition, as the second metal element contained in the bonding material 106, the metal constituting the cylindrical base material 104 is preferably the same kind of metal element. Titanium (Ti), copper (Cu), silver (Ag), or nickel (Ni) can be applied as such a second metal element.

  When the bonding material 106 has high wettability with the cylindrical sputtering target material 102, it becomes easy to fill the gap between the bonding material 106 and the cylindrical base material 104, and voids that cause poor adhesion are less likely to remain.

  Further, the bonding material 106 preferably has a shock absorption property (buffer material effect) in addition to the conductivity and thermal conductivity necessary for sputtering. In the case where the cylindrical sputtering target material 102 is ceramic, cracking is likely to occur when an external force is applied. At this time, if the bonding material 106 has the same hardness as the cylindrical sputtering target material and the cylindrical base material, the impact cannot be absorbed. However, if the hardness is lower than that of the cylindrical sputtering target material and the cylindrical base material, the bonding material 106 provided between the two becomes a buffer material, and the impact can be reduced.

  In the present embodiment, the second metal element (or the second metal element group) included in the bonding material 106 is included at a concentration that can adjust at least the wettability and hardness of the bonding material 106 within a certain range. Is preferred. For example, the second metal element (or the second metal element group) is contained in a proportion of 0.001 wt% or more and 0.5 wt% or less (10 ppm or more and 5000 ppm or less), and the others are the first metal elements By making it (or the first metal element group) and inevitable impurities, the wettability and hardness of the bonding material 106 can be controlled within a predetermined range. For example, when the second metal element is copper (Cu), it is preferably contained in the bonding material in the range of 0.2 wt% or more and 0.5 wt% or less (2000 ppm or more and 5000 ppm or less). When the second metal element is titanium (Ti), it is preferably contained in the bonding material in the range of 0.0018 wt% or more and 0.012 wt% or less (18 ppm or more and 120 ppm or less). Furthermore, when the second metal element is nickel (Ni), it is preferably contained in the bonding material in the range of 0.0044 wt% or more and 0.048 wt% or less (44 ppm or more and 480 ppm or less).

  Since the bonding material 106 is a metal material, if the wettability with at least the cylindrical sputtering target material 102 formed of a different material such as a metal oxide is poor, the bonding material 106 is interposed between the cylindrical sputtering target material and the cylindrical substrate. When filled, voids are easily formed. The wettability of the bonding material 106 can be evaluated by the contact angle of the bonding material 106 with respect to the cylindrical sputtering target material 102. That is, when the wettability is high, the contact angle is small, and conversely when the wettability is poor, the contact angle is large. In the present embodiment, the second metal element included in the bonding material 106 is included in a concentration range that can improve (decrease) the contact angle by 40% compared to the case where the second metal element is not included. desirable. That is, the contact angle is preferably 15 ° or more and 25 ° or less. Within such a numerical range, the bonding material 106 can be filled in the gap between the cylindrical sputtering target material 102 and the cylindrical base material 104 without including a gap.

  Further, the bonding material 106 needs to have a predetermined hardness in order to bond and hold the cylindrical sputtering target material 102 to the cylindrical base material 104. However, if the bonding material 106 is too hard, the function as a buffer material is deteriorated. In this embodiment, the hardness of the bonding material 106 is desirably 1.0 or more in Shore hardness, and preferably has a Shore hardness of 1.0 to 1.5. By making the Shore hardness within this range, it is possible to prevent the sputtering target from cracking.

  In the present embodiment, the hardness of the bonding material 106 is represented by Shore hardness, but it may be in the same range of hardness when converted to other hardnesses such as Rockwell hardness, Brinell hardness, Vickers hardness. .

  Inevitable impurity elements include lead (Pb), cadmium (Cd), iron (Fe), aluminum (Al), silicon (Si), arsenic (As), bismuth (Bi), phosphorus (P ), Sulfur (S) and the like, and these elements are contained at a concentration of 10 ppm, preferably 1 ppm or less, so that the characteristics of the bonding material 106 can be prevented from being affected.

  FIG. 3 shows a method of joining the cylindrical sputtering target material 102 to the cylindrical base material 104. The cylindrical sputtering target material 102 is inserted into the cylindrical substrate 104 so that the central axis is coaxial or substantially coaxial. The cylindrical base material 104 and the cylindrical sputtering target material 102 are arranged so that a gap 108 is provided between them. It is preferable that at least the gap 108 is held at a reduced pressure so that the bonding material 106 flows into the gap 108. Alternatively, nitrogen gas or inert gas may be passed through the gap 108 to replace it with air. In any case, it is preferable to prevent oxidation of the bonding material supplied in a molten state.

  The bonding material 106 is supplied from below the gap 108 in a state where the cylindrical base material 104 and the cylindrical sputtering target material 102 are upright. A heater 110 is provided around the cylindrical substrate 104 and the cylindrical sputtering target material 102. When filling the bonding material 106, the temperature in the vicinity of the cylindrical base material 104 and the cylindrical sputtering target material 102 is heated to a temperature equal to or higher than the melting point of the bonding material 106. In order to make the temperature uniform, hot air may be sent to the inside of the cylindrical base material 104, that is, the hollow portion to be heated from the inside.

  The heater 110 may divide the heating zone into a plurality of zones and individually control the temperature of each heating zone. For example, when the bonding material 106 is filled in the gap 108 and cooled, the bonding material 106 may be cooled from one to the other in the longitudinal direction of the cylindrical sputtering target material 102. By controlling the temperature in this way, voids (bubbles) remain and the melt-solidified region overlaps with the bonding material 106, thereby preventing generation of welds.

  Note that when the bonding material 106 is filled, the same or similar coating as the bonding material 106 may be provided on the inner surface of the cylindrical sputtering target material 102 and the outer surface of the cylindrical base material 104. This coating can be provided by a welder process.

  In the bonding material used for fixing the cylindrical sputtering material to the cylindrical base material, not only the gap but also the physical property value of the bonding material itself affects the bonding strength. It is considered that the bonding strength increases as the wettability of the bonding material increases. The wettability of the bonding material increases with an increase in the content of the second metal element (or the second metal element group) described in the present embodiment. On the other hand, if the content is too high, the bonding material cures and has impact resistance. Deteriorates. As shown in the present embodiment, at least titanium (Ti), copper (Cu), silver (Ag), nickel (Ni) is selected as the second metal element, and these metal elements are inevitably included. As shown in this embodiment, the second metal element (or the second metal element group) is changed to the first metal element (or the first metal element group). On the other hand, it is preferably contained at a concentration of 0.001 wt% or more and 0.5 wt% or less (10 ppm or more and 5000 ppm or less).

  As the second metal element contained in the bonding material 106, the same kind of metal as that constituting the cylindrical base material 104 may be contained. By including the same kind of metal element as the cylindrical base material 104, it becomes possible to improve wettability. In addition, the bonding strength of the bonding material 106 can be increased.

  In the present embodiment, the bonding material includes a first metal element (or first metal element group) included as a main component, and a second metal element that is the same metal element as the metal constituting the cylindrical base material. By including (or a metal element group), the wettability can be increased and the formation of voids can be prevented.

[Plate type sputtering target]
Although the cylindrical sputtering target material has been described above, the present invention is not limited to this and can also be applied to a flat plate sputtering target material. That is, when joining a flat-plate-type sputtering target to a flat substrate (backing plate), the joining material in this embodiment can be used.

  Various materials that can be sputtered, such as metal and ceramics, can be applied as the flat sputtering target material. As the ceramic, a metal oxide, a metal nitride, a sintered body of metal oxynitride, or the like can be used. As the metal oxide, a sintered body such as ITO, ZnO, IZO, and IGZO can be used as a flat plate type sputtering target.

  Also in the flat plate type sputtering target, by using the bonding material according to the present embodiment, the wettability of the bonding material can be increased, and the Shore hardness can be within the predetermined range described above. Thereby, when joining a flat sputtering target to a flat base material, it is suppressed that a space | gap is made in a joining material, and the crack of a sputtering target can be prevented after joining.

  The result of having evaluated the contact angle with respect to the amount of metal components contained in the case where indium (In) is used as the bonding material is shown. Six types of samples having different components were prepared using indium (In) as the metal element constituting the bonding material.

  Sample 1 is indium (In) with a purity of 99.99%, Sample 2 is indium (In) containing 2000 ppm of copper (Cu), and Sample 3 is indium (In) containing 5000 ppm of copper (Cu). Yes, sample 4 is indium (In) containing 7000 ppm of copper (Cu), sample 5 is indium (In) containing 10,000 ppm of copper (Cu), and sample 6 is indium containing 890 ppm of titanium (Ti). (In).

  In this embodiment, indium (In) corresponds to the first metal element constituting the bonding material, and copper (Cu) and titanium (Ti) correspond to the second metal element.

  The lower ground was evaluated in the state where the same kind of metal as each sample was applied to the ITO surface. This base surface is assumed to have been subjected to ultrasonic welding on the surface of the target and applied with the same type of metal as the bonding material.

As shown in FIG. 4, the contact angle θ was obtained by the following equation (1) from the height of the droplet when the sample was brought into contact with each base surface: a and the distance to the center: b / 2.

  The results of evaluating each sample are shown in Table 1. Sample 1 shows the result when indium (In) is used as the bonding material, and a contact angle of 25.9 ° is obtained. In contrast, sample 2 containing 2000 ppm of copper (Cu) is 16.7 °, sample 3 containing 5000 ppm of copper (Cu) is 16.4 °, sample 4 containing 7000 ppm of copper (Cu) is 19.4 °, copper Sample 5 containing 10,000 ppm of (Cu) has a contact angle of 12.8 °. Further, in Sample 6 containing 890 ppm of titanium (Ti), a contact angle of 24.4 ° is obtained.

  According to the present embodiment, the bonding material contains copper (Cu) or titanium (Ti) corresponding to the second metal element with respect to indium (In) corresponding to the first metal element. As a result, it is shown that the contact angle decreases. According to this embodiment, a contact angle of 10 ° or more and 25 ° or less is obtained as the contact angle. This numerical range is a small value as compared with the case where the second metal element is not included as the bonding material.

  From the results shown in Table 1, when the copper (Cu) is in the range of 2000 ppm to 10000 ppm and the titanium (Ti) is 890 ppm, the contact angle with the base surface is 25 ° or less. That is, the contact angles of Samples 2 to 6 are all small with respect to Sample 1, and the metal element corresponding to the second metal element contained in the bonding material is contained at a concentration of 20 ppm to 5000 ppm. It is suggested that it should be.

  Table 2 shows the results of evaluating the Shore hardness of each sample. Sample 1 with 99.99% indium (In) has a Shore hardness of 1.09 HS, while Sample 2 with a copper (Cu) content of 2000 ppm has a Shore hardness of 1.20 HS and contains copper (Cu). Sample 3 with an amount of 5000 ppm has a Shore hardness of 1.49 HS, Sample 4 with a copper (Cu) content of 7000 ppm has a Shore hardness of 1.61 HS, and Sample 5 with a copper (Cu) content of 10,000 ppm has a Shore hardness of 1. Sample 6 with 72 HS and titanium (Ti) content of 890 ppm has a Shore hardness of 1.77 HS. The Shore hardness was measured according to the Shore hardness test method (JISZ2246) defined in Japanese Industrial Standards.

  According to the results in Table 2, the Shore hardness increases as the content of copper (Cu) or titanium (Ti) increases with respect to indium (In). The hardness of In metal may affect the generation of cracks in the target and is preferably adjusted to 1.5 or less.

  According to the present embodiment, in the bonding material mainly composed of the first metal element, as the second metal element contained in the bonding material, contact is made in the range of at least 2000 ppm to 5000 ppm for copper (Cu). It is shown that the angle can be 15 ° or more and 25 ° or less, and even in that case, the Shore hardness can be 1.1 or more and less than 1.5.

  Generation of cracks in the target material when ITO is used as the flat plate sputtering target material, indium (In) is used as the first metal element in the bonding material, and the content of the second metal element is changed. Evaluated.

  The size of the flat-plate-type sputtering target material made of ITO is 127 mm × 508 mm × 6.35 mm (length × width × thickness), and the same bonding material as that used in Sample 2 or Sample 3 in Example 1 is used as the bonding material. Was used.

Sputtering was performed using argon (Ar) as the sputtering gas, sputtering pressure of 0.6 Pa, and sputtering power density (DC) of 2.3 W / cm ² .

  When the appearance of the target material after sputtering was evaluated, the occurrence of cracks or the like was not confirmed.

  The result of evaluating the contact angle when indium (In) is used as the first metal element in the bonding material and titanium (Ti) is used as the second metal element is shown. In this example, the results of evaluating samples with different contents of titanium (Ti) relative to indium (In) are shown.

  Sample 1 is indium (In) with a purity of 99.99%, which is the same as in Example 1. Sample 7 is indium (In) containing 18 ppm of titanium (Ti), sample 8 is indium (In) containing 60 ppm of titanium (Ti), and sample 9 is indium (In) containing 120 ppm of titanium (Ti). ). Sample 6 is indium (In) containing 890 ppm of titanium (Ti), which is the same as in Example 1.

  In this embodiment, indium (In) corresponds to the first metal element constituting the bonding material, and titanium (Ti) corresponds to the second metal element.

  The lower ground was evaluated in the state where the same kind of metal as each sample was applied to the ITO surface. This ground surface has a state in which the same kind of metal as the bonding material is applied to the surface of the target by ultrasonic welding.

  The results of evaluating each sample are shown in Table 3. Sample 7 containing 18 ppm of titanium (Ti) has a contact angle of 24.8 °, sample 8 containing 60 ppm of titanium (Ti) has a contact angle of 24.8 °, and sample 9 containing 120 ppm of titanium (Ti) has a contact angle of 24.5 °. It has been. The contact angle θ is obtained by the same method as in the first embodiment.

  According to the present embodiment, as the bonding material, titanium (Ti) corresponding to the second metal element is included with respect to indium (In) corresponding to the first metal element, so that the contact angle is reduced. It is shown. Specifically, a contact angle of 24 ° or more and 25 ° or less is obtained when the content of titanium (Ti) with respect to indium (In) is 18 ppm or more and 890 ppm or less.

  From the results of Table 3, when the titanium (Ti) is 18 ppm to 890 ppm, a contact angle of 25 ° or less with respect to the base surface is obtained. That is, all of the contact angles of the samples 6 to 9 with respect to the sample 1 are small, and titanium (Ti) corresponding to the second metal element contained in the bonding material has a concentration of 18 ppm or more and 890 ppm or less. It is shown that it should be included.

  Table 4 shows the results of evaluating the Shore hardness of each sample shown in Table 3. Sample 1 with 99.99% indium (In) has a Shore hardness of 1.09 HS, while Sample 7 with a titanium (Ti) content of 18 ppm has a Shore hardness of 1.28 HS and contains titanium (Ti). Sample 8 having an amount of 60 ppm has a Shore hardness of 1.52 HS, and Sample 9 having a titanium (Ti) content of 120 ppm has a Shore hardness of 1.70 HS. In addition, the Shore hardness was measured according to the Shore hardness test method (JISZ2246) prescribed | regulated by Japanese Industrial Standards similarly to Example 1.

  According to the result of Table 4, the shore hardness tends to increase as the content of titanium (Ti) increases with respect to indium (In). The hardness of indium (In) as a bonding material may affect the generation of cracks in the target, and the Shore hardness is preferably adjusted to 1.7 or less, preferably 1.5 or less.

  According to the present embodiment, in the bonding material mainly composed of indium (In), as the second metal element contained in the bonding material, titanium (Ti) is contacted in a range of at least 18 ppm and 120 ppm or less. It is shown that the angle can be 25 ° or less, and even in that case, the Shore hardness can be 1.1 or more and 1.7 or less.

  Table 4 shows the results of evaluating the Shore hardness of each sample when indium (In) is used as the first metal element and nickel (Ni) is used as the second metal element in the bonding material. In this example, the results of evaluating samples having different contents of nickel (Ni) relative to indium (In) are shown.

  Sample 1 is indium (In) with a purity of 99.99%, which is the same as in Example 1. Sample 10 is indium (In) containing 44 ppm of nickel (Ni), sample 11 is indium (In) containing 250 ppm of nickel (Ni), and sample 12 is indium (In) containing 480 ppm of nickel (Ni). ).

  In this embodiment, indium (In) corresponds to the first metal element constituting the bonding material, and nickel (Ni) corresponds to the second metal element.

  In Table 5, Sample 1 with 99.99% indium (In) has a Shore hardness of 1.09 HS, whereas Sample 10 with a nickel (Ni) content of 44 ppm has a Shore hardness of 1.12 HS and nickel. Sample 11 having a (Ni) content of 250 ppm has a Shore hardness of 1.21 HS, and Sample 12 having a nickel (Ni) content of 480 ppm has a Shore hardness of 1.46 HS. In addition, the Shore hardness was measured according to the Shore hardness test method (JISZ2246) prescribed | regulated by Japanese Industrial Standards similarly to Example 1.

  According to the result of Table 5, the shore hardness tends to increase as the content of nickel (Ni) increases with respect to indium (In). The hardness of indium (In) as a bonding material may affect the generation of cracks in the target, and the Shore hardness is preferably adjusted to 1.7 or less, preferably 1.5 or less.

  According to the present embodiment, in the bonding material mainly composed of indium (In), at least 44 ppm or more of nickel (Ni) may be included as the second metal element included in the bonding material. It is shown that the Shore hardness can be 1.1 or more and 1.7 or less in the range of at least 44 ppm or more and 480 ppm or less.

[Comparative example]
Using the bonding materials corresponding to Sample 4 to Sample 6 in Example 1, the same evaluation as above was performed. When the appearance of the target material after sputtering was evaluated, the occurrence of cracks and the like was confirmed.

  According to the present example, it was shown that the cracking of the sputtering target material can be prevented by using a bonding material having good wettability and a hardness (Shore hardness) within a predetermined range.

DESCRIPTION OF SYMBOLS 100 ... Cylindrical sputtering target, 102 ... Cylindrical sputtering target material, 104 ... Cylindrical base material, 106 ... Bonding material, 108 ... Gap part, 110 ... Heater

Claims (11)

A cylindrical base material formed of metal, a plurality of cylindrical sputtering target materials mounted on the cylindrical base material, and provided between the cylindrical base material and the plurality of cylindrical sputtering target materials A bonding material,
The plurality of cylindrical sputtering target materials include indium (In),
The bonding material includes indium (In) and copper (Cu) ,
The copper (Cu) is included at a concentration of 2000 ppm to 5000 ppm with respect to the indium (In),
Each of the plurality of cylindrical sputtering target materials is attached to the cylindrical base material with a gap, and the bonding material is exposed in the gap portion. A cylindrical base material formed of metal, a plurality of cylindrical sputtering target materials mounted on the cylindrical base material, and provided between the cylindrical base material and the plurality of cylindrical sputtering target materials A bonding material,
The plurality of cylindrical sputtering target materials include indium (In),
The bonding material includes indium (In) and titanium (Ti),
The titanium (Ti) is contained at a concentration of 44 ppm or more and 480 ppm or less with respect to the indium (In),
Each of the plurality of cylindrical sputtering target materials is attached to the cylindrical base material with a gap, and the bonding material is exposed in the gap portion. A cylindrical base material formed of metal, a plurality of cylindrical sputtering target materials mounted on the cylindrical base material, and provided between the cylindrical base material and the plurality of cylindrical sputtering target materials A bonding material,
The plurality of cylindrical sputtering target materials include indium (In),
The bonding material includes indium (In) and nickel (Ni),
The nickel (Ni) is contained at a concentration of 44 ppm or more and 480 ppm or less with respect to the indium (In),
Each of the plurality of cylindrical sputtering target materials is attached to the cylindrical base material with a gap, and the bonding material is exposed in the gap portion. 2. The cylindrical sputtering target according to claim 1 , wherein the bonding material has a contact angle with respect to the ITO surface of 16.4 ° or more and 16.7 ° or less. The cylindrical sputtering target according to claim 2 , wherein the bonding material has a contact angle with respect to the ITO surface of less than 25.0 °. The cylindrical sputtering target according to claim 1 , wherein the bonding material has a Shore hardness of 1.20 or more and 1.49 or less. The cylindrical sputtering target according to claim 2 , wherein the bonding material has a Shore hardness of 1.28 or more and 1.70 or less. The cylindrical sputtering target according to claim 3 , wherein the bonding material has a Shore hardness of 1.12 or more and 1.46 or less. The cylindrical sputtering target material, the cylindrical sputtering target according to any one of claims 1 to 3, characterized in that a ceramics sintered body containing indium (an In). The cylindrical sputtering target according to claim 9 , wherein the ceramic sintered body contains indium oxide. Cylindrical sputtering target according to any one of claims 1 to 3 surface roughness of the outer surface of the cylindrical base material (Ra) is equal to or not less than 1.8 .mu.m.

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