TWI815025B - Sputtering target and method for manufacturing the same - Google Patents

Abstract

This invention relates to a sputtering target and method for manufacturing the same capable of using a warped cylindrical base material as constitutional material, and provides a novel method for manufacturing sputtering target which is capable of eliminating warpage of a cylindrical base material even if the axial length of the cylindrical base material is relatively long, after heating during filling of joint material.

This invention proposes a method for manufacturing sputtering target, which includes measuring warpage magnitudeof a cylindrical base material, performing a processing for warping the cylindrical base material in a direction opposite to the warping direction, disposing a plurality of cylindrical target materials with intervals in the axial direction on the outside of the processed cylindrical base material, and bonding the cylindrical base material and the cylindrical target material with a binder.

Description

Sputtering target and manufacturing method thereof

The present invention relates to a sputtering target having a cylindrical base material and a plurality of cylindrical target materials and a manufacturing method thereof. In particular, it relates to a sputtering target that can use a cylinder that has been bent and deformed to become warped. A method for manufacturing a sputtering target using a shaped base material as a material.

When manufacturing organic EL (Electroluminescence, electroluminescence), liquid crystal display (display) or touch panel (touch panel), and other display devices (device), it is used to form ITO (indium tin oxide, indium tin oxide) ), etc., magnetron sputtering using a flat sputtering target in which a target is bonded to a flat substrate is the mainstream.

In recent years, a type of rotary sputtering (rotary sputtering) in which a cylindrical sputtering target in which a target material is bonded to the outer peripheral surface of a cylindrical base material is rotated around an axis has been put into practical use. And perform sputtering. This type of rotational sputtering can achieve much higher usage efficiency than a flat-plate type sputtering target, which has the advantage of achieving high productivity.

The glass substrate used in flat panel displays or solar cells has become increasingly larger. In order to form a thin film on this larger substrate, a strip with a length of 2m or more is required. cylindrical sputtering target. However, since it is difficult to produce a cylindrical target with a length of 2 m or more, a plurality of cylindrical targets are arranged in an axial direction outside the long cylindrical base material ( Also known as "split target").

For example, Patent Documents 1 and 2 disclose that a plurality of targets are produced by dividing the target into a plurality of pieces in the axial direction, and the plurality of targets are arranged in such a manner that they are arranged in the axial direction. The outer peripheral side of the cylindrical base material, and these components are joined by a joining material, thereby manufacturing the sputtering target.

As mentioned above, when the cylindrical base material changes into a long shape as the cylindrical sputtering target changes into a long shape, the influence of the warpage of the cylindrical base material cannot be ignored. In particular, long cylindrical base materials exceeding 2 meters have the problem that warpage occurs more often and the warpage amplitude is also larger. When the warpage of the cylindrical base material is large, the thickness of the joining material becomes uneven, and insufficient cooling occurs in the thinner portion of the joining material, which causes cracks during sputtering. etc. questions.

In recent years, sputtering equipment has been used to form films on larger tenth-generation glass substrates, and the total target length has exceeded 3m. When the total length of the target exceeds 3m, the aforementioned warping problem becomes more significant.

Therefore, Patent Document 2 has proposed a method that focuses on the eccentricity between the base material and the target. In order to suppress the eccentricity, the warpage of the cylindrical base material is confirmed before manufacturing the cylindrical target. If the warpage is large, use a stamping machine or the like to correct the warpage of the cylindrical base material.

In addition, Patent Document 3 is based on the premise that the cylindrical base material is curved, and each of a plurality of cylindrical targets is arranged according to the bending deformation of the cylindrical base material. That is, it discloses a method in which the central axis of each cylindrical target is tilted or biased in the radial direction at any position in the circumferential direction to ensure that the center axis of each cylindrical target is The required thickness of the joining material between the circumferential surface and the outer circumferential surface of the cylindrical base material.

[Prior technical literature]

[Patent Document]

Patent Document 1: Japanese Patent Application Publication No. 2010-100930

Patent Document 2: International Publication No. 2016/067717

Patent Document 3: Japanese Patent Application Publication No. 2018-159105

The invention described in Patent Document 2 proposes a method of measuring the warpage of a cylindrical base material in advance, and when the warpage is large, correcting the warpage using a stamping machine or the like. However, there will be the following problem: when filling the bonding material, if the cylindrical base material is heated in advance or the heated and melted bonding material is filled between the cylindrical base material and the target material, the cylindrical base material will become When the base material is heated, the corrected warpage will return to its original shape (also known as "warp recovery").

In addition, since the invention described in Patent Document 3 is based on the use of a curved cylindrical base material, there is a problem that when the axial length of the cylindrical target material is less than 750 mm, it can ensure On the other hand, when the axial length of the cylindrical target reaches 750 mm or more, it is difficult to ensure the required thickness of the joining material.

When a plurality of cylindrical targets are arranged in an array on the outside of a cylindrical base material to form a cylindrical sputtering target, the gaps between the cylindrical targets will become a junction during sputtering. Because of the nodules, it is better to reduce the number of divisions of the cylindrical target as much as possible. Therefore, as mentioned earlier, with the cylindrical splash The length of the plating target is getting longer year by year, and the axial length of the cylindrical target is also getting longer every year. There is a tendency that the cylindrical target will also become longer, and it will become impossible to fall within the range of less than 750mm.

Therefore, the present invention relates to a sputtering target that can use a warped cylindrical base material as a constituent material and a manufacturing method thereof, and is intended to provide a novel sputtering target manufacturing method and a novel sputtering target, which The novel sputtering target manufacturing method is to make the axial length of the cylindrical target material relatively long, and even after heating when filling the joining material (that is, even when filling the joining material, the cylindrical base is heated in advance material, or filling the heated and melted joining material between the cylindrical base material and the target material, and heating the cylindrical base material), which can also suppress the warpage of the cylindrical base material used. As a result, it is possible to manufacture a sputtering target in which the thickness of the joining material is uniform, the step difference between adjacent cylindrical targets is small, and the axial distance between adjacent cylindrical targets is uniform.

The invention provides a method for manufacturing a sputtering target. The sputtering target is provided with a cylindrical base material and a cylindrical target material; the manufacturing method includes the following steps:

Measure the warpage amplitude of cylindrical substrate;

Processing that causes the cylindrical base material to warp in a direction opposite to the original warping direction; and

Arrange a plurality of cylindrical targets at intervals in the axial direction on the outside of the processed cylindrical base material, and use a bonding material to connect the cylindrical base material and the cylindrical target materials are joined.

In addition, the present invention also provides a sputtering target including a cylindrical base material and a cylindrical target material, and the cylindrical base material and the cylindrical target material are joined with a joining material. Become a person; among them,

The length of at least one of the aforementioned cylindrical targets in the axial direction is 750 mm or more, the difference between the maximum and minimum thickness of the joining material is 1.0 mm or less, and the distance between the outer peripheral surfaces of adjacent cylindrical targets is The difference The maximum value of the amount is less than 0.5mm, and the difference between the maximum value and the minimum value of the axial distance between adjacent cylindrical targets is less than 0.2mm.

The manufacturing method provided by the present invention considers that the cylindrical base material is deformed again due to heating after processing (that is, the aforementioned warpage recovery), and the cylindrical base material is processed so that it warps in the same direction as the original one. The direction of curvature is opposite to the direction of reverse warping to a predetermined amplitude. Therefore, even if the axial length of the cylindrical target is relatively long, and even if it is heated when filling the joining material, the influence of the warpage of the cylindrical base material used can be eliminated, and the thickness of the joining material can be manufactured It is a sputtering target that is uniform, has a small step difference between adjacent cylindrical targets, and has a uniform axial distance between adjacent cylindrical targets.

Therefore, according to the manufacturing method provided by the present invention, a sputtering target can be manufactured. The sputtering target is provided with a cylindrical base material and a plurality of cylindrical target materials; wherein, at least one of the aforementioned cylindrical target materials The length in the axial direction is more than 750mm, the difference between the maximum and minimum thickness of the joining material is less than 1.0mm, and the maximum step difference between the outer peripheral surfaces of adjacent cylindrical targets is less than 0.5mm. The difference between the maximum value and the minimum value of the axial distance between adjacent cylindrical targets is 0.2mm or less.

Furthermore, with this kind of sputtering target, the thickness of the joint layer is ensured to be uniform, so not only is it less likely to crack during sputtering, but the step difference between the outer peripheral surfaces of adjacent cylindrical targets is also relatively small. The gap is small, and the intervals between the gaps are uniform, so the probability of abnormality during sputtering can be significantly reduced. Furthermore, since there is less warpage (i.e., bending), there is less shaking when the target is rotated, and the distance between the cylindrical target and the substrate can be kept constant, and the film formed by sputtering can be The quality is uniform.

1: sputtering target

2: Base material (cylindrical base material)

2a, 3a: Outer peripheral surface

3:Target (cylindrical target)

4:Joining materials

5: Dial gauge

40: Manufacturing device

43:Lower retaining member

43b, 44b: Target holding part

43c: Base material holding part

43d, 44c, 45c: Fixture

44:Target holding member

45:Substrate holding member

45b: Base material pressing part

46:Connecting components

47,48,50,51:O ring

49: Gap part

d: axial distance

h: step difference

Hmax: maximum value

Hmin: minimum value

L ₃ : axial length

P: Pressure direction

X: warp amplitude

Y: warpage amplitude

α: amplitude

FIG. 1 is a perspective view conceptually showing an example of a sputtering target.

FIG. 2 is a perspective view conceptually showing an example of a warped cylindrical base material.

FIG. 3 is a diagram conceptually showing an example of a method of measuring the warpage amplitude of a cylindrical base material.

FIG. 4 is a side view conceptually showing an example of a processing method of a cylindrical base material. FIG. 4(A) is a diagram showing a state before processing, and FIG. 4(B) is a diagram showing a state after processing.

FIG. 5 is an enlarged longitudinal cross-sectional view showing a main part of an example of the sputtering target produced.

FIG. 6 is an enlarged cross-sectional view of a main part for explaining the step difference h and the axial distance d between adjacent targets.

FIG. 7 is a longitudinal sectional view showing the manufacturing apparatus of the sputtering target used in the Example.

Next, the present invention will be described based on embodiment examples. However, the present invention is not limited to the embodiments described below.

<Manufacturing method of this target>

A method for manufacturing a sputtering target (referred to as "this target manufacturing method") as an example of an embodiment of the present invention is a method for manufacturing a sputtering target. The sputtering target is provided with a cylindrical base material 2 and a plurality of circular Cylindrical targets 3, 3, ^... ; the manufacturing method has the following steps:

Measure the warpage amplitude and warpage direction of the cylindrical base material 2 (referred to as the "measurement step");

Perform processing to warp the cylindrical base material 2 in a direction opposite to the original warping direction (referred to as "processing step"); and

A plurality of cylindrical target materials 3, 3, ^... are arranged at intervals in the axial direction of the cylindrical base material 2 on the outside of the cylindrical base material 2 processed as described above, and are connected with a joining material 4. Join the cylindrical base material 2 and the aforementioned cylindrical target material 3.

(This sputtering target)

As shown in FIG. 1 , a sputtering target ("this sputtering target") 1 manufactured by this target manufacturing method is composed of a plurality of cylinders arranged at intervals in the axial direction of a cylindrical base material 2 The cylindrical target material 3 is arranged outside a cylindrical base material 2, and the cylindrical base material 2 and the cylindrical target material 3 are joined with a joining material 4 (not shown).

Details of this sputtering target 1 will be described later. Here, the structural components will be explained first.

(Target)

The target is composed of a plurality of cylindrical targets 3, 3, ^... , and the plurality of cylindrical targets 3 are arranged in a cylindrical shape at appropriate intervals in the axial direction of the cylindrical base material 2. The outer peripheral side of the base material 2 .

Each cylindrical target material 3 only needs to have an inner diameter larger than the outer diameter of the cylindrical base material 2 .

The length of cylindrical targets tends to become longer year by year, but on the other hand, it has been pointed out that when the length of cylindrical targets becomes longer, especially when it becomes 750 mm or more, there is a problem that the thickness of the joining material cannot be ensured. . However, according to the present target manufacturing method, this problem can be eliminated, and the effects of the present invention can be further enjoyed.

Therefore, from the perspective of being able to better enjoy the effects of the present invention, it is preferable that the axial length L ₃ of at least one of the plurality of cylindrical targets 3, 3, ^... is at least 750 mm, and wherein 850mm or more (950mm or more among them, 1400mm or more among them) is better.

The material of the cylindrical target 3 is not limited. Examples include Cu (copper), Al (aluminum), In (indium), Sn (tin), Ti (titanium), Ba (barium), Ca (calcium), Zn (zinc), Mg (magnesium), Ge An oxide of any one or more of (germanium), Y (yttrium), La (lanthanum), Al (aluminum), Si (silicon), Ga (gallium), and W (tungsten).

Examples of the aforementioned oxides include In-Sn-O (indium tin oxide), In-Ti-O (indium titanium oxide), In-Ga-Zn-O (indium gallium zinc oxide), In -Zn-Sn-O (indium zinc tin oxide), In-Ga-Zn-Sn-O (indium zinc tin oxide), Ga-Zn-O (gallium zinc oxide), In-Zn-O ( Indium zinc oxide), In-Ga-O (indium gallium oxide), IWO (indium tungsten oxide), I-Zn-WO (indium zinc tungsten oxide), Zn-O (zinc oxide), Sn- Ba-O (tin-barium oxide), Sn-Zn-O (tin-zinc oxide), Sn-Ti-O (tin-titanium oxide), Sn-Ca-O (tin-calcium oxide), Sn-Mg- O (tin magnesium oxide), Zn-Mg-O (zinc magnesium oxide), Zn-Ge-O (zinc germanium oxide), Zn-Ca-O (zinc calcium oxide), Zn-Sn-Ge- O (zinc tin germanium oxide), Cu ₂ O (cuprous oxide), CuAlO ₂ (copper aluminum dioxide), CuGaO ₂ (copper gallium dioxide), CuInO ₂ (copper indium dioxide), etc.

(cylindrical base material)

The cylindrical base material 2 is preferably one in which the central axis is a straight line and the outer peripheral surface is also in a cylindrical shape parallel to the axis. However, as shown in FIG. 2 , the newly used cylindrical base material or the recycled cylindrical base material 2 is warped into a curved shape (in other words, an arch shape). The cylindrical base material The outer peripheral surface of 2 has deviation from the linear axis direction.

The material of the cylindrical base material 2 may be metal such as Ti (titanium), SUS (Steel Special Use Stainless, stainless steel material standard) or Cu. However, it is not limited to this.

(joining material)

The bonding material 4 is supplied in a molten state to the gap between the cylindrical base material 2 and each cylindrical target material 3 arranged at a predetermined position on the outer peripheral side of the cylindrical base material 2 when manufacturing the sputtering target. , and then hardened after filling the gap to join the cylindrical base material 2 and the cylindrical target material 3 .

The material of the bonding material 4 is not particularly limited as long as it can be used for bonding the target material and the base material. Examples include low melting point solders such as indium metal, indium tin metal, or indium alloy metal in which a trace amount of metal components are added to indium.

The melting point of the aforementioned low melting point solder is 150 to 250°C. Therefore, when filling the joining material 4, the joining material 4 is usually heated to 150 to 300°C to melt it.

<Measurement procedure>

In the measurement step, the warp width and warp direction of the cylindrical base material 2 used as a constituent material are measured.

The method of measuring the warpage amplitude is not particularly limited. For example, the cylindrical base material 2 can be rotated about its axis to measure the displacement amplitude (that is, the warpage amplitude) of the outer peripheral surface, or the cylindrical base material 2 can also be placed laterally on a platform and along the The vertical line erected on the platform is used to measure the displacement amplitude of the distance between the smooth surface of the platform and the outer peripheral surface 2a of the cylindrical base material 2, that is, the warpage amplitude. It can also be measured by other methods.

The location where the warpage amplitude is measured may be one location, or two or more locations in the length direction of the cylindrical base material 2 .

The cylindrical base material 2 is often warped in an arch shape, so if the warp amplitude is measured near the center in the longitudinal direction, the maximum warp amplitude and its warp direction can be measured.

However, it may not warp into an arch shape, so it is better to measure the warp amplitude at multiple locations at intervals in the length direction. For example, it is preferably measured at an interval of 100 mm to 1000 mm, and more preferably at an interval of 200 mm or more or 800 mm or less (especially an interval of 500 mm or less).

This is an example of a specific measurement method for measuring warpage amplitude.

As shown in FIG. 3 , the cylindrical base material 2 is installed horizontally and rotatably, and a dial gauge 5 is placed against the outer peripheral surface 2 a of the cylindrical base material 2 . The aforementioned cylindrical substrate 2 is rotated once to measure the reading of the aforementioned dial gauge 5 . Furthermore, the difference (Hmax-Hmin) between the maximum value Hmax and the minimum value Hmin of the reading of the dial gauge 5 can be set as the warpage amplitude.

At this time, any means can be used to rotate the axis of the cylindrical base material 2 . For example, it is placed between two rotating rollers and rotated, or the vicinity of both ends of the cylindrical base material is placed in the groove of a support table having a V-shaped groove, and is placed by hand or The roller is used to rotate it by any means.

In the measuring step, the original warp amplitude , and measure the warp amplitude Y and warp direction of the heated cylindrical base material 2 as described above.

When heating the cylindrical base material 2 and measuring the warp amplitude Y and warp direction of the heated cylindrical base material, the heating temperature of the cylindrical base material 2 is preferably assumed to be: The temperature at which the cylindrical base material 2 is heated (that is, when the heated and melted joining material 4 is filled between the cylindrical base material 2 and the cylindrical target material 3), or due to the filled The joining material 4 is used to subject the cylindrical base material 2 to a heating temperature. However, if the temperature is too high, the surface of the cylindrical base material 2 may be oxidized. From this point of view, as for the heating temperature of the cylindrical base material 2 at this time, it is preferable to heat it so that its surface temperature becomes 150 to 300°C, and to heat it so that its surface temperature becomes 160°C or more. The temperature is preferably below 240°C (within 170°C or below or below 230°C).

The heating method of the cylindrical base material 2 is not particularly limited. For example, the base material can be placed in an electric furnace or the like and heated from the outside, or a heater can be provided inside the base material to heat it from the inside.

<Processing steps>

In the processing step, the cylindrical base material 2 is processed to reversely warp by a predetermined amplitude α in a direction opposite to the original warping direction.

For example, as shown in FIG. 4 , at the measurement position in the measurement step, the cylindrical base material 2 is bent by applying pressure in the direction opposite to the warpage direction measured in the previous measurement step, and as shown in FIG. 4(B ), It suffices to process the cylindrical base material 2 so that it warps in the direction opposite to the original warping direction by an amplitude α (in other words, it is displaced from the linear axis by an amount α).

As for the position where the pressure is applied, for example, when the cylindrical base material 2 is warped into an arch shape, one location in the center in the axial direction can be pressed and deformed. Furthermore, it is preferable that the position measured in the measurement step is pressurized. For example, it is preferable to measure at intervals of 100 mm to 1000 mm, and to apply pressure to deform each measurement point.

The amplitude α (mm) required to cause the cylindrical base material 2 to warp in a direction opposite to the original warping direction is preferably determined based on the warp amplitude X or Y measured in the aforementioned measurement step. This is because the larger the warpage amplitude X or Y, the larger the warp recovery will be due to heating after processing.

For example, in the measurement step, when the original warp amplitude of the obtained cylindrical base material 2 is measured to obtain the warp amplitude X, the warp amplitude α (mm) is preferably set to X(mm)×(0.10 to 2.00), where X(mm)×0.50 or more or X(mm)×1.50 1.40 or less, more preferably X (mm) × 0.90 or more or X (mm) × 1.30 or less).

In addition, in the measuring step, when the obtained cylindrical base material 2 is heated, and the warping width of the heated cylindrical base material 2 is measured to obtain the warping width, what is required to warp it? The width α (mm) is preferably set to Y (mm) × (0.50 to 1.50), where Y (mm) ) × 0.90 or more or Y (mm) × 1.30 or less, and among them, Y (mm) × 0.95 or more or Y (mm) × 1.25 or less) is more preferred.

If heating is actually carried out and the warp amplitude Y after heating is measured, and the amplitude α to be warped is determined based on the warp amplitude Y, the heating operation of the obtained cylindrical base material 2 can be added. The amplitude α is then determined, so warpage recovery can be further reduced.

In the processing method of pressurizing the cylindrical base material 2 to warp it, for example, as shown in FIG. 4(A) , for example, the measurement position (one position or a plurality of positions) in the measurement step is A method in which the cylindrical base material 2 is pressed in a direction opposite to the original direction of warping. In addition, the P system in Fig. 4(A) shows the pressing direction. In this case, examples of means for applying pressure include mechanical press processing, forging processing, and the like.

However, any method may be used as long as the cylindrical base material 2 can be warped to a desired extent.

At this time, in order to prevent the roundness of the cylindrical base material from changing, an arc-shaped one formed according to the shape of the cylindrical base material 2 may be used for terminals to which pressure is applied.

In addition, further heat treatment (annealing) may be performed if necessary.

In addition, the processing method of pressurizing and warping the cylindrical base material 2 may be repeated. That is, the process of pressurizing and warping the cylindrical base material 2 and further pressurizing and warping the cylindrical base material 2 may be repeated, and finally the cylindrical base material 2 can be warped. The warpage reaches a predetermined amplitude α.

In addition, the cylindrical base material 2 may be repeatedly heated (the warpage width Y is measured) and pressed to warp it, and further heated and pressed to warp it. The warping process finally causes the cylindrical base material 2 to warp to a predetermined amplitude α. At this time, it is sufficient to measure the warpage amplitude Y B after heating only at the beginning.

<Arrangement of cylindrical targets>

Using the cylindrical base material 2 processed as described above, a plurality of cylindrical targets 3, 3, ^... are arranged on the outer periphery of the cylindrical base material 2 so as to be arranged at appropriate intervals in the axial direction. side.

The cylindrical targets 3 are preferably arranged at intervals of 0.15 mm to 0.50 mm in the axial direction.

<Join>

To sum up, it only needs to be set as follows: after arranging the cylindrical target material 3, the cylindrical base material 2 and the cylindrical target material 3 are heated, and the cylindrical base material 2 and the cylindrical target material 3 are heated. The gap between the cylindrical target materials 3 is filled with the molten joining material 4 , and the joining material 4 is cooled to join each cylindrical target 3 to the periphery of the cylindrical base material 2 via the joining material 4 .

Before filling the bonding material 4 , the temperature at which the cylindrical base material 2 and the cylindrical target material 3 are heated is preferably set to a temperature equal to or higher than the temperature of the bonding material 4 .

The temperature of the joining material 4 when filling the joining material 4 is a temperature above the melting point of the joining material, and is preferably heated to 150 to 300°C, and preferably to 160°C or more or 240°C or less (wherein to 170℃ or more or 230℃ or less) is more preferable.

As the filling and cooling method of the joining material, known methods can be used.

<This sputtering target>

According to this target manufacturing method, the influence of the warpage of the cylindrical base material 2 can be eliminated even by heating when filling the joining material, so that the following sputtering target can be manufactured.

As a preferred example of this sputtering target, a sputtering target can be cited. The sputtering target is provided with a cylindrical base material 2 and a plurality of cylindrical target materials 3, 3, ^... , wherein the plurality of cylindrical targets are At least one of the cylindrical targets 3, 3, ^... has an axial length L ₃ of 750 mm or more, the difference between the maximum and minimum thickness of the joining material 4 is 1.0 mm or less, and the adjacent cylindrical targets have The maximum value of the step difference h in the outer peripheral surfaces 3a and 3a of 3 and 3 is less than 0.5mm, and the difference between the maximum and minimum value of the axial distance d between adjacent cylindrical targets 3 and 3 is 0.2mm. the following.

In addition, from the viewpoint of enjoying the effect of the present invention more, the length of the cylindrical base material 2 is preferably 2.0m to 4m, with 3.0m or more or 3.8m or less (and 3.3m or more or 3.7m among them). m or less) is better.

The outer diameter of the cylindrical base material 2 is preferably 125 mm to 140 mm, and more preferably 130 mm or more or 135 mm or less (and 132 mm or more or 134 mm or less) is more preferred.

The inner diameter of the cylindrical target 3 is preferably 127mm to 142mm, and more preferably 132mm or more or 137mm or less (and 134mm or more or 136mm or less) is more preferred.

The wall thickness of the cylindrical target 3 is preferably 5 mm to 20 mm, and more preferably 6 mm or more or 16 mm or less (8 mm or more or 13 mm or less) is more preferred.

From the perspective of better enjoying the effects of the present invention, the axial length L ₃ of at least one of the cylindrical targets 3 is preferably 750 mm to 1500 mm, and is preferably more than 850 mm or less than 1450 mm (wherein more than 950 mm is preferred). or below 1450mm) is better.

If the difference between the maximum value and the minimum value of the thickness of the joining material 4 is 1.0 mm or less, the thickness of the joining material 4 is ensured to be uniform, and therefore it is possible to prevent the target from cracking due to insufficient cooling, for example, in a thin portion of the joining material. etc., which can inhibit the occurrence of cracks during sputtering.

From this point of view, the difference between the maximum value and the minimum value of the thickness of the joining material 4 is preferably 0.5 mm or less, and more preferably 0.3 mm or less.

At this time, the thickness of the joining material 4 is preferably 0.5 mm or more, and more preferably 0.7 mm or more (especially 1 mm or more).

The thickness of the joint material 4 can be measured by an ultrasonic flaw detection device.

If the maximum value of the step difference h between the outer peripheral surfaces 3a, 3a of adjacent cylindrical targets 3, 3 (that is, in a pair of adjacent cylindrical targets 3, 3 in the axial direction, each The outer peripheral surfaces 3a and 3a are in contact with each other. If the maximum value of the step difference (h) between the adjacent end edges in the axial direction is less than 0.5mm, it can reduce the occurrence of abnormalities during sputtering. Specifically, it can reduce the occurrence of arcing or the resulting The probability of chipping or rupture occurring. On the other hand, if the maximum value of the step difference h is larger than 0.5 mm, the cylindrical target 3 on one side may become bulged, causing adverse effects such as abnormal discharge at the bulging edge.

From this point of view, the maximum value of the step difference h is preferably 0.3 mm or less, and more preferably 0.2 mm or less.

In addition, the step difference h can be measured using, for example, a depth gauge.

Furthermore, if the difference between the maximum value and the minimum value of the axial distance (interval) d between adjacent cylindrical targets 3, 3 is 0.2 mm or less, the occurrence of abnormalities during sputtering, such as end The parts may come into contact with each other due to thermal expansion during sputtering, resulting in chipping or cracking. For example, in a portion where the distance d in the axial direction is large, the cylindrical base material 2 may be exposed, and the base material components may be sputtered and mixed into the film in the form of impurities. On the other hand, in the portion where the distance d in the axial direction is small, the adjacent cylindrical targets 3 and 3 may collide with each other when thermally expanding due to the heat of sputtering, and the cylindrical target 3 may be broken. possibility.

From this point of view, the difference between the maximum value and the minimum value of the axial distance d between adjacent cylindrical targets 3 is preferably 0.15 mm or less, and more preferably 0.1 mm or less.

In addition, the aforementioned axial direction distance (interval) d can be measured using, for example, a feeler gauge.

<Description of statement>

In this specification, when expressed as "A to B" (where A and B are arbitrary numbers), unless otherwise stated, it means "above A and below B", and also includes "better than A". It means "big" or "preferably smaller than B".

In addition, when expressed as "above A" (A is an arbitrary number) or "below B" (B is an arbitrary number), it also includes "preferably greater than A" or "preferably less than B" The meaning of the content.

[Example]

The present invention is further illustrated by the following examples. However, the following examples are not intended to limit the present invention.

<Example 1>

The cylindrical base material (length 3400mm, diameter 133mm, wall thickness 4mm) that is recycled is placed on a base that can be supported for axis rotation, and is installed horizontally and axis-rotatably. and place the fixed dial gauge hanging down from above against the outer surface of the central portion of the cylindrical base material in the length direction, and make the cylindrical base material rotate once to measure the reading of the aforementioned dial gauge, and measure The difference between the maximum value Hmax and the minimum value Hmin of the reading (Hmax-Hmin) is regarded as the warpage amplitude X (initial stage).

Next, the above-mentioned cylindrical base material was placed in an electric furnace, heated so that the surface temperature was maintained at 230° C. for one hour, and the warp amplitude Y after heating (after heating) was measured in the same manner as above.

Next, a press machine is used to process the longitudinal center portion of the cylindrical base material in a direction (- direction) opposite to the original direction of warping (+ direction), so that the center portion is pressed in the opposite direction. (- direction) warpage reaches amplitude α (=Y×1.0).

Next, using the cylindrical base material processed as mentioned above, and using the manufacturing apparatus 40 shown in FIG. 7, the ITO cylindrical sputtering target was manufactured as follows.

That is, four ITO cylindrical divided targets with an outer diameter of 153mm, an inner diameter of 133mm, and a length of 300mm, 750mm, 750mm, and 300mm are prepared, and the outer peripheral surface of the cylindrical divided target is Heat-resistant film and tape are masked, and an ultrasonic soldering iron is used to lay indium solder on the joint surface (inner peripheral surface).

On the other hand, an ultrasonic soldering iron is also used to prime the indium solder on the joint surface (outer peripheral surface) of the cylindrical base material processed as described above.

The cylindrical base material was attached to the base material holding part 43c equipped with an O-ring 48 made of Teflon (registered trademark).

Next, an O-ring 47 made of Teflon (registered trademark) is attached to the target holding part 43b, and one of the aforementioned cylindrical divided targets is attached to the target holding part 43b. At this time, the offset between the lower end of the cylindrical base material and the lower end of the cylindrical divided target is adjusted to 0.1 mm by the lower holding member 43 . Furthermore, a gap 49 is formed between the cylindrical base material and the cylindrical divided target material.

Furthermore, the remaining cylindrical divided targets are stacked on the aforementioned cylindrical divided targets. An O-ring 51 made of Teflon (registered trademark) with a thickness of 0.5 mm is interposed between the cylindrical divided targets. An O-ring 50 is installed above the uppermost cylindrical divided target, and the uppermost cylindrical divided target is mounted on the target holding part 44b, and the cylindrical part is held by the target holding part 44b. The target is pressed from its upper side. At this time, the positions of the nine cylindrical divided targets are adjusted so that all steps between the cylindrical divided targets become 0.2 mm or less. In this way, the upper end of the cylindrical target is held by the target holding member 44 .

Next, the base material pressing part 45b is pressed against the upper end part of the cylindrical base material, and the upper end part of the cylindrical base material is held by the base material pressing part 45b. At this time, while measuring the distance between the surface of the cylindrical target and the surface of the cylindrical base material with a depth gauge, adjust the position of the auxiliary tool so that the upper end of the cylindrical base material and the upper end of the cylindrical target are aligned The offset becomes 0.1mm or less.

Finally, the lower holding member 43, the target holding member 44, and the base holding member 45 are respectively fixed to the titanium connecting member 46 through the fixing tools 43d, 44c, and 45c, thereby fixing the cylindrical base material The cylindrical target is reliably fixed to the manufacturing device 40 .

The manufacturing device 40, the cylindrical base material, and the cylindrical target material are heated to 180°C.

From the upper side of the target holding member 44 , an amount of molten indium solder of 175° C. sufficient to join the cylindrical target and the cylindrical base material is injected into the gap 49 .

The melted solder injected into the manufacturing device 40, the cylindrical base material, the cylindrical target material, and the gap portion 49 is cooled.

After confirming that the indium solder has solidified, the manufactured ITO cylindrical sputtering target (sample) is removed from the manufacturing device 40, the O-ring is removed, and the indium solder remaining between the cylindrical divided targets is taken out.

The ITO cylindrical sputtering target (sample) manufactured in this manner was measured using an ultrasonic flaw detector (manufactured by Hitachi Power Solutions Co., Ltd.: FS LINE) as follows. The thickness of the joint material. Specifically, the bonding layer is calculated based on the difference in detection time between the reflected wave at the interface between the target material and the bonding layer and the reflected wave at the interface between the bonding layer and the base material, and the propagation speed of the ultrasonic wave in the bonding layer. thickness. In addition, a probe of 10 MHz was used, and the transmission speed of ultrasonic waves in the bonding layer (indium metal) was set to 2700 m/s.

The measurement position of the thickness of the joint material is set in a target segment, two points offset 10mm inward from each end of the target segment in the axial direction, and these two points are The measured points are divided equally into points such that the equally divided value becomes 50 mm or less, and each of the measuring points in the axial direction is divided into twelve positions (0°, 30°) every 30° in the circumferential direction. °, 60°, ^... and 330° positions). In one base material, each target segment to be bonded was measured at the aforementioned position, and the difference between the maximum value and the minimum value was defined as the thickness difference of the bonded materials.

In addition, use a depth gauge to measure all the step differences h between adjacent targets, and find the maximum value of the step difference h.

In addition, use a feeler gauge to measure all axial distances d between adjacent targets, and find the difference between the maximum value and the minimum value.

The measurement positions of all step differences h and axial distance d between adjacent targets are set to twelve locations (0°, 30°, 60°, ^... and 330°) every 30° in the circumferential direction. each location).

<Example 2>

In Example 1, except that the longest cylindrical target material was changed to 850 mm, an ITO cylindrical sputtering target (sample) was manufactured in the same manner as in Example 1, and each value was measured.

<Example 3>

In Example 1, except that the longest cylindrical target material was changed to 1100 mm, the ITO cylindrical sputtering target (sample) was manufactured similarly to Example 1, and each value was measured.

<Example 4>

In Example 1, except that the longest cylindrical target was changed to 1450 mm, an ITO cylindrical sputtering target (sample) was manufactured in the same manner as in Example 1, and each value was measured.

<Example 5>

In Example 4, the heating of the cylindrical base material was changed to not be performed. That is, instead of placing the cylindrical base material in an electric furnace for heating and measuring the warp amplitude Y after heating, a stamping machine is used to process the cylindrical base material without heating, and the length of the cylindrical base material is The central part of the direction is pressurized in the direction (- direction) opposite to the original direction of warping (-+- direction), so that it can warp in the opposite direction (- direction) by an amplitude α (=X×1.0) , Except for this, an ITO cylindrical sputtering target (sample) was produced in the same manner as in Example 4, and each value was measured.

<Example 6>

In Example 3, except that the material of the cylindrical target was changed to IGZO, an IGZO cylindrical sputtering target (sample) was manufactured in the same manner as in Example 3, and each value was measured.

<Comparative example 1>

In Example 2, an ITO cylindrical sputtering target (sample) was manufactured in the same manner as in Example 2 except that the processing to warp the cylindrical base material was not performed, and each value was measured. .

<Comparative example 2>

In Example 2, an ITO cylinder was produced in the same manner as in Example 2, except that the cylindrical base material was not warped to the opposite side of the original warping direction in the processing step of warping it. shape sputtering target (sample), and measure each value.

[Table 1]

Measure the warpage amplitude of the cylindrical base material used, press the cylindrical base material in the opposite direction to the original warping direction, and make the cylindrical base material face the opposite direction to the original warping direction. By processing in this way, even if the axial length of the cylindrical target is longer (that is, even if the axial length of at least one cylindrical target is 750mm or more), and even if After heating when filling the joining material (that is, even when filling the joining material, the cylindrical base material is heated in advance, or the heated The thermally melted joining material is filled between the cylindrical base material and the target material, and the cylindrical base material is heated), which can also eliminate the influence of the warpage of the cylindrical base material. The results show that Reducing the difference between the maximum and minimum thickness of the joining material can also reduce the step difference between the outer peripheral surfaces of adjacent cylindrical targets, and can also reduce the axial direction difference between adjacent cylindrical targets. The difference between the maximum and minimum distance.

2: Cylindrical base material

P: Pressure direction

X: warp amplitude

α: amplitude

Claims (7)

A method of manufacturing a sputtering target, which includes a cylindrical base material and a cylindrical target material; the manufacturing method includes the following steps: a measuring step, which measures the warpage amplitude of the cylindrical base material; and The processing step is to perform the aforementioned processing of warping the cylindrical base material in such a manner that the processed cylindrical base material will warp in a direction opposite to the warping direction before processing; and, in the axial direction Arranging a plurality of cylindrical targets at intervals on the outside of the processed cylindrical base material, and joining the cylindrical base material and the aforementioned cylindrical target material with a joining material; In the aforementioned measurement step, after the aforementioned cylindrical base material is heated, the warpage amplitude of the heated cylindrical base material is measured; in the aforementioned processing step, when the warpage amplitude Y is measured in the aforementioned measurement step In this case, the aforementioned processing is performed so that the processed cylindrical base material will warp in a direction opposite to the warping direction before processing by an amplitude of Y×0.50 to 1.50. The manufacturing method of a sputtering target as claimed in claim 1, wherein in the aforementioned measuring step, after the aforementioned cylindrical base material is heated to 150 to 300°C, the warp of the heated cylindrical base material is measured. Curvature amplitude Y. The manufacturing method of a sputtering target as claimed in claim 1 or 2, wherein in the aforementioned measuring step, the amplitude of the displacement of the outer peripheral surface of the cylindrical base material is measured as the warpage amplitude. The manufacturing method of a sputtering target according to claim 1 or 2, wherein the axial length of at least one of the aforementioned cylindrical targets is 750 mm or more. The manufacturing method of a sputtering target as described in claim 1 or 2, wherein the difference between the maximum value and the minimum thickness of the joining material of the sputtering target is 1.0 mm or less, and the thickness of the adjacent cylindrical target is 1.0 mm or less. The maximum value of the step difference between the outer peripheral surfaces is less than 0.5mm, and the difference between the maximum value and the minimum value of the axial distance between adjacent cylindrical targets is less than 0.2mm. A sputtering target comprising a cylindrical base material made of Ti and a cylindrical target material, and the cylindrical base material and the cylindrical target material are bonded with a solder containing In with a melting point of 150 to 250°C. Joined; wherein the length in the axial direction of at least one of the aforementioned cylindrical targets is 750 mm or more, the difference between the maximum and minimum thickness of the joining materials is 1.0 mm or less, and the adjacent cylindrical targets The maximum value of the step difference between the outer peripheral surfaces of the materials is less than 0.2mm, and the difference between the maximum value and the minimum value of the axial distance between adjacent cylindrical target materials is less than 0.2mm. The sputtering target according to claim 6, wherein the length of the cylindrical base material is 2 m or more.

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