JP6354435B2 - Cylindrical sputtering target and manufacturing method thereof - Google Patents

Description

  The present invention relates to a cylindrical sputtering target used in a sputtering apparatus such as a magnetron sputtering apparatus and a method for manufacturing the same.

  There exists a magnetron sputtering apparatus provided with the cylindrical sputtering target as a magnetron sputtering apparatus. In this magnetron sputtering apparatus, a magnet is arranged inside a cylindrical sputtering target, and sputtering is performed while rotating the target while cooling the target by flowing cooling water inside the target.

As a cylindrical target used in such a sputtering apparatus, for example, in Patent Document 1, a cylindrical shape in which a buffer member such as a sheet-like carbon felt having a conductivity is rolled and inserted between a backing tube and a target material. A target is disclosed.
Patent Document 2 relates to a rod-type evaporation source used for arc ion plating. In this rod-type evaporation source, a metal tube, which is a backing tube, is inserted into a hollow portion of a cylindrical target, and the inner circumference of these target materials. A cylindrical metal spring is interposed between the surface and the outer peripheral surface of the metal tube.
In the sputtering target of Patent Document 3, an Al-containing Si alloy is provided as a target layer on the outer peripheral surface of a columnar substrate that is a backing tube by a thermal spraying method through a metal intermediate layer such as Mo, Ti, W, or Ni. It has been.

In Patent Document 4, a short base as a backing tube is joined with indium or the like on the inner peripheral side of the divided short target material, and a male screw part and a female screw part are formed at both ends of the base. The bases are connected in series by this threaded portion to form a long shape.
In the cylindrical sputtering target of Patent Document 5, a plurality of cylindrical target materials are bonded to the outer peripheral surface of a cylindrical base material via a bonding material such as indium, and the cylindrical target materials are bonded at intervals. It is described that this interval can prevent the target material from cracking due to thermal expansion during sputtering.

JP 2002-155356 A Japanese Patent No. 4015874 Japanese Patent Laid-Open No. 5-86462 JP 2013-181221 A JP 2008-184640 A

Although a long cylindrical sputtering target is required in response to an increase in the size of the substrate, the technique described in the above-mentioned patent document has the following problems.
When providing the sheet-like carbon felt of Patent Document 1 and the metal spring of Patent Document 2, the longer the length, the more difficult it is to insert the carbon felt or metal spring between the target material and the backing tube. If it is forcibly inserted, cracks may occur in the case of a ceramic target material. In addition, as described in Patent Document 3, the workability is poor when formed by a thermal spraying method. In the technique described in Patent Document 4, a long product can be manufactured. However, since a plurality of connecting portions are formed by screw portions, rigidity becomes insufficient when the product is long. Although the structure described in Patent Document 5 is excellent in measures against thermal expansion, it is difficult to interpose the bonding material without any gap between each target material fitted from the end of the long backing tube. Moreover, even if a defect such as damage occurs in any of the target materials, it is necessary to replace the whole.

  The present invention has been made in view of such circumstances, and can be provided in a long shape while increasing the overall rigidity while ensuring the conductivity and heat transfer between the target material and the backing tube. An object of the present invention is to provide a cylindrical sputtering target that can be partially repaired and a method of manufacturing the same.

The cylindrical sputtering target of the present invention includes a plurality of target units obtained by joining a cylindrical short backing tube to the inner periphery of a cylindrical short target material with a bonding material, and these target units are adjacent to each other and conductive. via sexual inclusions possess a long backing tube mounted cylindrical outer periphery, said conductive inclusions are conductive liquid or a conductive paste, elastic seal between each other said short backing tube A member is provided .

In addition, the manufacturing method of the cylindrical sputtering target of the present invention is to prepare a plurality of target units in which a cylindrical short backing tube is joined to the inner periphery of a cylindrical short target material with a bonding material. The unit is attached to the outer periphery of a cylindrical long backing tube in a state adjacent to each other and through a conductive inclusion, and a conductive liquid or a conductive paste is used as the conductive inclusion, and the short backing is used. An elastic seal member is provided between the tubes .

The overall rigidity is ensured by the long backing tube. The rigidity of the long backing tube can prevent the occurrence of deflection when attached to the sputtering apparatus, and can form a film with high accuracy. In this case, since each short backing tube is individually joined to the inner periphery of each short target material by a bonding material, cracking, peeling, and the like due to a difference in thermal expansion coefficient between the target material and the backing tube are unlikely to occur. Furthermore, since it is possible to use indium or the like that can absorb the difference in thermal expansion as the bonding material, it is possible to more reliably prevent cracking and peeling.
The short target material and the short backing tube are joined by a bonding material, and conductive inclusions are interposed between the short backing tube and the long backing tube. It can be secured sufficiently. Commercially available conductive grease can be applied as the conductive liquid.

  When attaching a target unit to a long backing tube, since each target unit is supported and reinforced by a short backing tube, it is possible to prevent cracking of the target material when attaching via a conductive inclusion. . Further, when any short target is damaged or worn, the target unit can be individually removed from the long backing tube and only the target unit at the corresponding location can be replaced, and the replacement work is facilitated.

Further, the conductive inclusion is a conductive liquid or a conductive paste , and an elastic seal member is provided between the short backing tubes , whereby the long backing tube and the short backing tube are formed by the elastic seal member. It is possible to prevent leakage of the conductive liquid from between the two.

  According to the cylindrical sputtering target and the manufacturing method thereof of the present invention, the short target material and the short backing tube are joined by the bonding material, and conductive inclusions are interposed between the short backing tube and the long backing tube. Therefore, the conductivity and heat transfer between them can be sufficiently ensured, and the overall rigidity can be ensured by the long backing tube, so that the short target material is not cracked or peeled off. In addition, high-accuracy film formation is possible, and maintenance such as replacement of some target units is easy.

It is sectional drawing which shows embodiment of the cylindrical sputtering target of this invention. It is a partially expanded sectional view of FIG. It is sectional drawing of the target unit used for the cylindrical sputtering target of FIG.

Embodiments of a cylindrical sputtering target and a method for producing the same according to the present invention will be described below with reference to the drawings.
1 and 2 show cross-sectional views of the cylindrical sputtering target 1, and FIG. 3 shows a cross-sectional view of the target unit 2 used in the cylindrical sputtering target 1.
The cylindrical sputtering target 1 includes a plurality of target units 2 in which a cylindrical short backing tube 13 is bonded to the inner circumference of a cylindrical short target material 11 with a bonding material 12, and the plurality of target units 2 are electrically conductive. It has a cylindrical long backing tube 21 that is held on the outer periphery via the inclusion 3.

In this case, the materials of the short target material 11, the short backing tube 13, and the long backing tube 21 are appropriately selected according to the purpose of film formation, and are not particularly limited. It is made of a metal such as Cu, Ag, Ti, or an oxide such as SiO ₂ , Al ₂ O ₃ , Ga ₂ O ₃ , ZrO ₂ , Cr ₂ O _3, etc. The short backing tube 13 and the long backing tube 21 are made of SUS. Ti, Cu, etc. are provided in a cylindrical shape. As will be described later, since the short target material 11 is held and reinforced by the short backing tube 13, it is particularly advantageous when an oxide-based target material that is easily broken is used as the short target material 11.

Also, although these dimensions are not particularly limited, the short target material 11 and the short backing tube 13 are formed to have the same length, and the diameter of the bonding material 12 is interposed between them. It is set as the dimension which can ensure the clearance which can interpose the material 12. Further, the short backing tube 13 only needs to secure rigidity when the target unit 2 is attached to and detached from the long backing tube 21. Therefore, the short backing tube 13 may be thinner than the long backing tube 21.
In the target unit 2 in which the short target material 11 and the short backing tube 13 are integrated, both ends of the short target material 11 and the short backing tube 13 are arranged in an airtight manner between the two. It is integrated by the bonding material 12. However, since each target unit 2 is pressed by an adjacent unit, when the short target material 11 is a material that is easily cracked, such as a ceramic, the length is manufactured slightly shorter than the short backing tube 13, and the short target material 11 It is desirable not to contact each other directly.
As the bonding material 12, a metal material such as an In-based low melting point solder material can be used, and a material having conductivity and capable of absorbing a difference in thermal expansion during sputtering is used.

An annular groove 15 is formed in the inner peripheral portions of both ends of the short backing tube 13, and when the short target materials 11 are abutted against each other, a recess formed by the annular groove 15 is provided between the short target materials 11. The elastic seal member 16 such as an annular packing is closely fitted in the recess.
The diameters of the short backing tube 13 and the long backing tube 21 are set to dimensions that can secure a clearance for interposing the conductive inclusion 3 therebetween.

The long backing tube 21 holds a plurality of target units 2 adjacent to each other in series on the outer periphery thereof. The long backing tube 21 is formed to have a length larger than the total length of the rows of the target units 2, and is formed on the outer periphery of both end portions. A screw portion 22 is formed.
The conductive inclusion 3 interposed between the long backing tube 21 and each target unit 2 is composed of a conductive liquid, a conductive paste, a metal cylindrical spring, a conductive sheet, and the like. The carbon felt described in 1 and the metal spring described in Patent Document 2 can be applied. When the conductive liquid is used, specifically, a commercially available general conductive grease based on mineral oil or synthetic oil may be used. As the conductivity at that time, the volume resistivity is desirably 1.0 × 10 ¹⁰ Ω · cm or less.
The illustrated example shows an example in which a conductive liquid is used as the conductive inclusion 3, and each target unit 2 is adjacent to each other via an elastic seal member 16, and nuts are formed at both ends of the long backing tube 21. It is hold | maintained in the state pressed by the axial direction with the fasteners 5, such as.

When manufacturing the cylindrical sputtering target 1 comprised as mentioned above, the several target unit 2 is produced by fixing the short target material 11 to the outer periphery of the short backing tube 13 via the bonding material 12 first. .
And the fastener 5 is fixed to the external thread part of the one end part side of the elongate backing tube 21 as a thing for retaining, The target unit 2 is mounted | worn and fitted one by one from the other end side. At this time, the conductive inclusion 3 is interposed between the target unit 2 and the long backing tube 21 so as to close the gap between them. When the conductive inclusion 3 is a conductive sheet or the like, a large resistance may act when the target unit 2 is attached to the long backing tube 21 via the conductive inclusion 3. Since the short target material 11 is reinforced by the short backing tube 13, the short target material 11 is not cracked.
When the conductive inclusion 3 is a conductive liquid or conductive paste, an annular elastic seal member 16 is interposed between the short backing tubes 13 of the adjacent target units 2 as shown in FIG.

Then, while attaching the plurality of target units 2 to the outer periphery of the long backing tube 21 via the conductive inclusions 3, the target units 2 are successively connected with the elastic backing member 16 interposed between the short backing tubes 13. Set up.
Finally, the fastener 5 is screwed into the male threaded portion 22 at the other end of the long backing tube 21 and the target unit 2 is pressed in the axial direction so that the elastic seal member 16 is tightly sandwiched. While fixing, the target unit 2 is prevented from coming off.
Note that it is not always necessary to first fix the fastener 5 to one end side, and the fastener 5 may be fixed to both ends of the long backing tube 21 after all the target units 2 are attached.

In the cylindrical sputtering target 1 manufactured by such a method, each target unit 2 is obtained by joining a short target material 11 and a short backing tube 13 with a bonding material 12. Since it is attached to the tube 21 via the conductive inclusions 3, the conductivity and heat transfer between the long backing tube 21 and each short target material 11 can be ensured satisfactorily.
Therefore, when used for DC sputtering, it functions well as an electrode, and also when using an oxide-based ceramic as a target material, the accumulation of electric charge during RF sputtering is suppressed, thereby preventing the occurrence of arc discharge. Can do.
Moreover, since high rigidity can be exhibited by the long backing tube 21, the generation | occurrence | production of a deflection | deviation when it attaches to a sputtering device can be prevented, and highly accurate film-forming can be performed. Since each short target material 11 is joined to the outer periphery of the short backing tube 13 by a bonding material 12 such as indium, cracks and peeling due to a difference in thermal expansion coefficient during sputtering hardly occur.

  When problems such as wear or chipping occur in some short target materials 11, it is possible to remove the fastener 5 and replace only the corresponding target unit 2, and there is no need to replace the entire cylindrical sputtering target 1, which is costly. Also excellent. In this case, since the target unit 2 is attached to the long backing tube 21 by fitting and fixed by the fastener 5, the attachment and detachment thereof is easy. By preparing a plurality of target units 2 and keeping them in stock, it is possible to cope with a short delivery time even when there is a malfunction.

  While the embodiment has been described above, various modifications can be made without departing from the spirit of the present invention. In addition, the present invention can correspond to cylindrical sputtering targets having a diameter from a small diameter to a large diameter and various lengths.

DESCRIPTION OF SYMBOLS 1 Cylindrical sputtering target 2 Target unit 3 Conductive inclusion 5 Fastener 11 Short target material 12 Bonding material 13 Short backing tube 15 Annular groove 16 Elastic seal member 21 Long backing tube 22 Male screw part

Claims (2)

A plurality of target units in which a cylindrical short backing tube is bonded to the inner periphery of a cylindrical short target material with a bonding material, and these target units are attached to the outer periphery via conductive inclusions in a state adjacent to each other. was possess a cylindrical elongate backing tube,
The conductive inclusion may be a conductive liquid or a conductive paste, and a cylindrical sputtering target in which an elastic seal member is provided between the short backing tubes . A plurality of target units are prepared by joining cylindrical short backing tubes with a bonding material on the inner periphery of a cylindrical short target material, and these target units are mutually attached to the outer periphery of a cylindrical long backing tube. It is a method of attaching to the adjacent state via a conductive inclusion ,
A method of manufacturing a cylindrical sputtering target , wherein a conductive liquid or a conductive paste is used as the conductive inclusion, and an elastic seal member is provided between the short backing tubes .

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