JPWO2011129089A1 - Sputtering target manufacturing method and sputtering target - Google Patents

Abstract

A sputtering target having crystal characteristics required as a target and mechanical strength required as a backing plate and a method of manufacturing the same are provided. In the method for manufacturing a sputtering target according to an embodiment of the present invention, when the support portion 12 is formed, the peripheral portion of the metal plate 100 is spun while maintaining the metal plate 100 at a predetermined temperature or lower. The predetermined temperature is set to an appropriate temperature at which relaxation of internal stress due to the annealing effect can be suppressed, for example. By adopting a spinning method for forming the support portion, stress can be applied to the entire support portion 12. Thereby, the strength improvement of the whole support part 12 by work hardening can be aimed at. Moreover, since the temperature rise exceeding the predetermined temperature of the support part 12 accompanying a process is prevented, the fall of the hardness of the support part 12 by recovery | restoration of crystal structure is suppressed. [Selection] Figure 3

Description

  The present invention relates to a sputtering target manufacturing method in which a target portion and a backing plate portion are integrally formed, and a sputtering target.

  Conventionally, a sputtering target for forming a thin film has been formed from a circular or rectangular flat metal plate, and is incorporated into a sputtering apparatus in a state of being integrally joined to a backing plate. The backing plate is a metal member for connecting the sputtering target to the sputtering cathode, and has a cooling water circulation channel formed therein. Brazing, electron beam welding, or the like is employed for joining the sputtering target and the backing plate. However, joining by brazing may cause the target and backing plate to peel off due to the temperature rise of the target during sputtering, while joining by electron beam welding creates a pinhole in the backing plate. There is a possibility to make it.

  Therefore, in recent years, a technique for integrally forming a sputtering target and a backing plate has been proposed. For example, Patent Document 1 below describes a method of manufacturing a sputtering target having a target portion and a support portion that supports the target portion by deep drawing a single plate (blank) made of a metal or an alloy. Has been.

  Generally, a sputtering target is required to have a uniform and normal recrystallized structure for sputtering film formation. On the other hand, the backing plate is required to have enough strength to withstand the cooling water pressure. In the method described in Patent Document 1, blanks controlled by the crystal characteristics of the target portion are produced, and the support portion is formed by pressing the peripheral edge of the blank. As a result, plastic working can be performed only on the support portion, and thus the crystal characteristics of the target portion can be maintained well.

JP-A-6-158297 (paragraphs [0016] and [0023], FIG. 1)

  However, with the method described in Patent Document 1, it is considered difficult to form a support portion having mechanical strength required as a backing plate. In other words, the hardness of the support portion is expected to be improved by work hardening by receiving compressive stress and bending stress due to press working. For example, in the case of an aluminum alloy, the crystal structure of the support portion is recovered by heat generated during processing. Or it is thought that recrystallization is inevitable and the desired hardness cannot be obtained. Further, in deep drawing by pressing, stress is considered to be concentrated on the boundary portion between the target portion and the support portion, and therefore it is difficult to provide a desired strength over the entire support portion.

  In view of the circumstances as described above, an object of the present invention is to provide a sputtering target having both the crystal characteristics required as a target and the mechanical strength required as a backing plate, and a method for producing the same.

In order to achieve the above object, a method for producing a sputtering target according to an embodiment of the present invention includes a step of forming a disk-shaped metal plate whose structure is controlled.
An annular support portion is formed on the peripheral portion of the metal plate by drawing and deforming the peripheral portion of the metal plate by spinning while maintaining the metal plate at a predetermined temperature or lower.

In addition, a sputtering target according to one embodiment of the present invention includes a disk-shaped target portion and an annular support portion.
The target portion is formed of a metal material whose structure is controlled and has a first hardness.
The support portion has a second hardness that is 1.2 times or more of the first hardness, and is formed by spinning the periphery of the target portion.

It is sectional drawing of the sputtering target which concerns on one Embodiment of this invention. It is a top view of the said sputtering target. It is a schematic side view of the spinning processing apparatus explaining the manufacturing method of the said sputtering target.

The manufacturing method of the sputtering target which concerns on one Embodiment of this invention includes the process of forming the disk-shaped metal plate by which structure | tissue control was carried out.
An annular support portion is formed on the peripheral portion of the metal plate by drawing and deforming the peripheral portion of the metal plate by spinning while maintaining the metal plate at a predetermined temperature or lower.

  The disk-shaped metal plate whose structure is controlled means a metal sheet whose crystal structure, crystal structure, crystal orientation and the like required as a sputtering target are controlled. The metal plate forms a target portion that receives a sputtering action during film formation. And the said support part is integrally formed in the peripheral part of a metal plate, and functions as a backing plate into which cooling water is introduced.

  In the method for manufacturing the sputtering target, the peripheral portion of the metal plate is spun while maintaining the metal plate at a predetermined temperature or lower when the support portion is formed. The predetermined temperature is set to an appropriate temperature at which relaxation of internal stress due to the annealing effect can be suppressed, for example. By adopting a spinning method for forming the support portion, stress can be applied to the entire support portion. Thereby, the strength improvement of the whole support part by work hardening can be aimed at. Moreover, since the temperature rise exceeding the predetermined temperature of the support part accompanying a process is prevented, the fall of the hardness of the support part by recovery of crystal structure is suppressed.

  As described above, according to the method for manufacturing a sputtering target, it is possible to form a support portion having a hardness of 1.2 times or more with respect to the hardness of the target portion. Thereby, it is possible to obtain a sputtering target having both crystal characteristics required as a target and mechanical strength required as a backing plate.

  The said predetermined temperature can be suitably set with the kind of metal material which comprises a metal plate, a composition, etc. For example, when the metal plate is formed of aluminum or an aluminum alloy, the predetermined temperature can be 130 ° C. By spinning the metal plate at 130 ° C. or lower, it is possible to stably form a support portion having a desired hardness or mechanical strength.

  The method of processing the metal plate while controlling the temperature is not particularly limited. In one embodiment, the peripheral portion of the metal plate is drawn and deformed by spinning, the metal plate is cooled, and the peripheral portion of the metal plate is further The drawing is deformed by spinning. In this way, by alternately performing the processing and cooling, the support portion can be deformed into a desired shape while suppressing a temperature rise associated with the processing.

  The metal plate may be cooled directly, or the metal plate may be indirectly cooled by cooling a metal mold that holds the metal plate.

The sputtering target which concerns on one Embodiment of this invention comprises a disk-shaped target part and a cyclic | annular support part.
The target portion is formed of a metal material whose structure is controlled and has a first hardness.
The support portion has a second hardness that is 1.2 times or more of the first hardness, and is formed by spinning the periphery of the target portion.

  According to the sputtering target, it is possible to satisfy the crystal characteristics required for the target and the mechanical strength of the support required for the backing plate.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 are a cross-sectional view and a plan view of a sputtering target according to an embodiment of the present invention. The sputtering target 10 of this embodiment is formed in a substantially shallow dish shape as a whole, and has a target portion 11 and a support portion 12. The target portion 11 and the support portion 12 are made of the same metal material, and are integrally formed by drawing and deforming a metal plate.

  The target part 11 has a disk shape and is formed of a metal material whose structure is controlled. The target portion 11 is made of aluminum or an aluminum alloy. In the present embodiment, the target portion 11 is made of an aluminum copper alloy (Al-0.5% Cu). In addition, the metal material which forms the target part 11 is not restricted to said example, The other metal or alloy material used as a sputtering target may be used.

  The target unit 11 is controlled in advance to the crystal structure and crystal orientation required as a sputtering target. The crystal structure is typically a fine and uniform recrystallized structure, but is controlled to an optimum structure state according to the required target quality. The metal plate whose structure is controlled in this way is manufactured through predetermined plastic processing such as forging and rolling and predetermined heat treatment.

  The diameter of the target unit 11 is set to an appropriate size according to the specification. In the present embodiment, the target portion 11 is formed with a diameter of 300 mm to 700 mm, but of course not limited thereto.

  The thickness of the target portion 11 is not particularly limited, and is appropriately set within a range that can withstand the pressure of cooling water introduced during sputtering and that does not hinder the formation of the support portion 12 and the like. In the present embodiment, the target portion 11 is formed with a thickness of 20 mm to 50 mm.

  The support portion 12 is formed in an annular shape along the periphery of the target portion 11. The support portion 12 is formed by spinning the periphery of the target portion 11 as will be described later. Therefore, the support portion 12 is subjected to plastic working and has increased in hardness due to work hardening, and the hardness is higher than the hardness of the target portion 11. In particular, the support part 12 has a hardness of 1.2 times or more of the hardness of the target part 11 by receiving a spinning process in a temperature-controlled state as will be described later.

  The support part 12 has a function as a backing plate for connecting the target part 11 to a cathode of a sputtering apparatus (not shown). On the back side of the target portion 11, a space portion 13 having a predetermined volume is formed by the support portion 12. In the present embodiment, the introduction of cooling water into the space 13 suppresses an excessive temperature rise of the target unit 11 during sputtering.

  In the present embodiment, a flange portion 12 a is formed at the tip of the support portion 12 in order to improve the detachment workability of the sputtering target 10. Mounting holes such as bolts are appropriately formed in the flange portion 12a. In addition, an annular groove in which the seal ring is mounted may be formed on the bottom surface side of the flange portion 12a. The formation of the flange portion 12a is not essential and may be omitted.

  The support portion 12 has a truncated cone shape whose diameter gradually increases from the target portion 11 side, but the shape is not particularly limited, and may be, for example, a cylindrical shape. Moreover, the height of the support part 12 is not specifically limited, It sets suitably according to a specification.

  Next, the manufacturing method of the sputtering target 10 of this embodiment is demonstrated. In addition, the numerical value and composition given below are only examples, and are not limited to these examples.

  First, a disk-shaped metal ingot having a diameter of 200 mm and a thickness of 150 mm is produced. Next, this ingot is hot-forged at a temperature of 280 ° C. to 300 ° C. to produce a disk-shaped ingot having a diameter of 190 mm and a thickness of 150 mm. Subsequently, the ingot is water-quenched, annealed at 280 ° C. to 300 ° C., and further cold forged to produce a disc-shaped ingot having a diameter of 450 mm and a thickness of 25 mm. Then, after quenching with water, it is annealed again at 280 ° C to 300 ° C. The metal plate 100 whose structure is controlled to a predetermined target characteristic as described above is drawn and deformed by the spinning device 20 shown in FIG.

  As illustrated in FIG. 3A, the spinning processing apparatus 20 includes a mold 21 and a motor 24 that rotates the mold 21. The metal plate 100 is mounted on the spinning device 20 by being sandwiched between the mold 21 and the holder 22. A drive shaft 23 of a motor 24 is coupled to the center of the mold 21, and the mold 21, the metal plate 100, and the holder 22 are integrally rotated by driving the motor 24.

  The mold 21 is arbitrarily determined according to the shape of the sputtering target 10 to be produced. The holder 22 presses the central region 101 of the metal plate 100 against the mold 21. A central region 101 of the metal plate 100 sandwiched between the mold 21 and the holder 22 forms the target portion 11 of the sputtering target 10.

  The peripheral region 102 of the metal plate 100 positioned outside the holder 22 is pressed toward the side peripheral surface of the mold 21 by the squeezing roller 30. Thereby, the peripheral area | region 102 of the metal plate 100 deform | transforms gradually as shown in FIG.3 (B) and FIG.3 (C).

  The peripheral region 102 of the metal plate 100 is subjected to drawing deformation, whereby internal stress (internal strain) is accumulated and hardened. That is, the peripheral region 102 of the metal plate 100 is increased in strength by work hardening and has a higher hardness than the central region 101 of the metal plate 100.

  On the other hand, the processing energy is converted into thermal energy, so that the temperature of the peripheral region 102 of the metal plate 100 increases. The heat generation of the metal plate 100 promotes rearrangement of the crystal structure of the peripheral region 102 and promotes relaxation of internal stress. That is, due to the annealing effect due to heat generation of the metal plate 100, an increase in hardness due to work hardening of the peripheral region 102 is suppressed.

  In order to prevent such a phenomenon, in this embodiment, the temperature of the metal plate 100 is controlled during the spinning process of the metal plate 100, and the cooling process of the metal plate 100 is performed so that the temperature does not reach a predetermined temperature or higher. To do. Thereby, the excessive temperature rise of the peripheral area | region 102 of the metal plate 100 can be avoided, and the fall of the hardness of the peripheral area | region 102 can be prevented.

  The said predetermined temperature can be suitably set with the kind of metal material which comprises a metal plate, a composition, etc. For example, when the metal plate is formed of aluminum or an aluminum alloy, the predetermined temperature can be 130 ° C. By maintaining the temperature of the metal plate 100 during processing at 130 ° C. or lower, the recovery phenomenon of the crystal structure can be effectively suppressed, and the decrease in hardness due to relaxation of internal stress can be prevented.

  The temperature management of the metal plate 100 may directly manage the temperature of the metal plate 100 or may manage the temperature of the mold 21. Further, the temperature management of the metal plate 100 may be performed not only by temperature management by temperature measurement but also by, for example, the processing time and the processing rate.

  As a method for cooling the metal plate 100, natural cooling of the metal plate 100 or forced cooling such as water cooling or air cooling can be employed. Further, the metal plate 100 may be indirectly cooled by cooling the mold 21. In order to maintain the metal plate 100 at a predetermined temperature or less, the drawing processing of the metal plate 100 may be performed intermittently at appropriate intervals (for example, 10 minutes to 40 minutes), or the metal plate 100 is cooled. However, continuous processing may be used. Since the heating rate during processing varies depending on the processing speed, the processing rate of the metal plate 100, and the like, the cooling method of the metal plate 100 may be changed according to the progress of processing.

  The drawing process of the metal plate 100 is continued until the peripheral region 102 contacts the side peripheral surface of the mold 21. Thereby, the annular support part 12 surrounding the periphery of the target part 11 is formed. The flange portion 12 a of the support portion 12 is formed by pressing the peripheral edge of the metal plate 100 against the flange portion 21 a of the mold 21.

  The sputtering target 10 is manufactured as described above. In the present embodiment, since the peripheral region 102 is drawn while the temperature of the metal plate 100 is controlled, the support portion 12 can be formed without slowing the curing rate. Thereby, the support part 12 can be formed with the hardness of 1.2 times or more of the hardness (for example, Vickers hardness (Hv) 30) of the target part 11. FIG. In addition, by controlling the temperature of the metal plate 100, the change in the crystal structure of the target portion 11 due to the temperature rise can be suppressed, and the crystal state of the target portion 11 whose structure is controlled can be stably maintained.

  According to the experiments by the present inventors, the hardness ratio of the support part to the target part when the drawing process was continuously performed without temperature control was 1.1, as described above. It was confirmed that when the support portion was formed while managing the metal plate at 130 ° C. or less, the hardness ratio could be 1.3 or more. It has also been confirmed that a support portion having a hardness ratio of 1.4 could be formed by performing drawing while maintaining a relatively long interval (for example, 40 minutes).

  In the present embodiment, a spinning method is used to form the support portion 12. As a result, the peripheral region 102 of the metal plate 100 can be uniformly squeezed over the entire region, and the entire region of the support portion 12 can be finished to a substantially uniform hardness. Therefore, the uniformity of hardness can be improved as compared with a processing method in which deformation stress acts on the bent portion intensively as in the press processing method. As a result, since the mechanical characteristics of the support part 12 required as a backing plate are ensured, a highly reliable sputtering target can be manufactured. Moreover, since the manufacturing cost of a metal mold | die can be reduced compared with the press processing method, the reduction of the manufacturing cost of the sputtering target 10 can be aimed at.

  As described above, according to the present embodiment, it is possible to manufacture the sputtering target 10 having both the target portion 11 having desired crystal characteristics and the support portion 12 having excellent mechanical strength. In addition, a large sputtering target can be stably manufactured.

  The embodiment of the present invention has been described above, but the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Sputtering target 11 ... Target part 12 ... Supporting part 20 ... Spinning processing apparatus 21 ... Mold 100 ... Metal plate

Claims (6)

Form a disc-shaped metal plate with controlled structure,
A method of manufacturing a sputtering target, wherein an annular support portion is formed on a peripheral portion of the metal plate by drawing and deforming the peripheral portion of the metal plate by spinning while maintaining the metal plate at a predetermined temperature or lower. It is a manufacturing method of the sputtering target according to claim 1,
The said predetermined temperature is 130 degreeC. The manufacturing method of a sputtering target. It is a manufacturing method of the sputtering target according to claim 1,
The step of forming the support portion includes
A step of drawing and deforming a peripheral portion of the metal plate by spinning, a step of cooling the metal plate,
And a step of drawing and deforming the peripheral edge of the metal plate by spinning. It is a manufacturing method of the sputtering target according to claim 3,
The step of cooling the metal plate includes a step of cooling a mold that holds the metal plate. A disk-shaped target portion formed of a metal material whose structure is controlled and having a first hardness;
A sputtering target having a second hardness that is 1.2 times or more of the first hardness, and an annular support portion formed by spinning the periphery of the target portion. The sputtering target according to claim 5,
The metal material is aluminum or an aluminum alloy.

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