JP2015017297A - In-BASED CYLINDRICAL SPUTTERING TARGET, AND MANUFACTURING METHOD OF THE SAME - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable easily and surely integrating an In-based cylindrical target material and a cylindrical backing tube, and surely holding the In-based cylindrical target material at time of usage.SOLUTION: In a manufacturing method of an In-based cylindrical sputtering target in which an In-based cylindrical target material 20 containing In is bonded to an outer peripheral surface 41 of a cylindrical backing tube 40, the In-based cylindrical target material 20 is formed on the outer peripheral surface 41 of the cylindrical backing tube 40 through a compacting process in which a green compact with a relative density of 97% or more is formed on the outer peripheral surface 41 by compression molding using a cold isostatic pressing method of metal powders 22 for the target material including an In component into a state that the metal powders 22 are tightly contacted to surround the outer peripheral surface 41 of the cylindrical backing tube 40.

Description

  The present invention relates to an In-based cylindrical sputtering target used in a magnetron sputtering apparatus and a method for manufacturing the same.

  As a magnetron sputtering apparatus, there is a magnetron sputtering apparatus provided with a cylindrical sputtering target that performs sputtering while rotating a cylindrical target material. In this magnetron sputtering apparatus, a magnet is placed inside a cylindrical target material, and cooling water is allowed to flow inside the cylindrical target material, thereby performing sputtering while cooling and rotating the cylindrical target material. .

  A sputtering apparatus using such a cylindrical sputtering target is suitable for film formation over a large area and has a feature that the use efficiency of the target material is very high. In general, a flat plate target material has a usage efficiency of about 10 to 30%, whereas a cylindrical target has a very high usage efficiency of about 80% because the entire surface of the target material is an erosion region. Moreover, since a cylindrical sputtering target can distribute | circulate a cooling water inside, cooling efficiency is high. Therefore, high power can be applied to the target material, and film formation can be performed at high speed.

  Conventionally, such cylindrical sputtering targets are mainly used in film-forming apparatuses for surface coating of building glass, and are hardly applied to the manufacture of electronic components that require strict film-forming atmosphere management. In recent years, however, a rotating cathode type sputtering apparatus has been developed for manufacturing large-sized electronic components such as solar cells and flat panel displays. For this reason, it is required to produce a high-quality cylindrical sputtering target at a low cost.

  For the production of the cylindrical sputtering target, for example, a casting method in which a molten metal of the target material is cast or a thermal spraying method in which the metal powder of the target material described in Patent Document 1 or Patent Document 2 is sprayed onto a backing tube. Laws are utilized. Further, Patent Document 2 describes that the process of bonding a cylindrical target to a backing tube is complicated and expensive to manufacture.

In Patent Document 3, in order to efficiently form a Cu—In—Ga—Se quaternary alloy film that serves as a light absorption layer of a solar cell, conventionally, a Cu—Ga binary alloy is formed on the In film. Forming a Cu-In-Ga ternary alloy film by one-time sputtering using a Cu-In-Ga ternary alloy target in the process of forming a laminated film by forming a film And omitting the process. In this Patent Document 3, a Cu-In-Ga ternary alloy target is prepared by gas atomizing a Cu-In-Ga molten metal to produce a Cu-In-Ga ternary alloy powder, and the alloy powder is subjected to high-pressure sintering. It is described that an In-based cylindrical target is produced by bonding.
And the sintered body of the Cu—In—Ga ternary alloy target produced in this way is processed into a predetermined shape and then bonded to the backing tube to be used as an In-based cylindrical sputtering target. The

2012-107296 2012-229453 2009-120862

However, in the cylindrical sputtering target manufactured by the thermal spraying method described in Patent Document 1 or Patent Document 2, the crystal grain size forming the cylindrical target increases, and abnormal discharge occurs during use due to variations in density and structure. Easy to do. For this reason, it is required to produce a cylindrical target material by powder sintering.
However, in the In-based target material containing In, the cylindrical target material body produced by powder sintering has a low melting point (about 150 ° C. in the case of Cu-In-Ga), so the cylindrical target material and backing It is difficult to join the tube by bonding. Even if bonding is performed using a bonding material having a melting point lower than that of the cylindrical target material, the bonding material melts due to the temperature rise during use, and the In-based cylindrical sputtering target used in the rotating state is securely held. It becomes difficult.

  The present invention has been made in view of such circumstances, and can easily and reliably integrate an In-based cylindrical target material and a cylindrical backing tube, and can reliably hold the In-based cylindrical target material during use. The purpose is to make it possible.

  The present invention relates to a method for producing an In-based cylindrical sputtering target in which an In-based cylindrical target material containing In is bonded to the outer peripheral surface of a cylindrical backing tube, the metal powder for target material having In as a component composition Is compacted by a cold isostatic pressing method in a state of being in close contact with the outer peripheral surface of the cylindrical backing tube, thereby forming a compact having a relative density of 97% or more on the outer peripheral surface. The In-based cylindrical target material is formed on the outer peripheral surface of the cylindrical backing tube by a compacting process.

In the cold isostatic pressurization method, compression molding is performed by applying isotropic pressure to the object using hydraulic pressure, so there is no friction with the metal, as in press processing using a mold, In addition, since the pressure acts isotropically, the surface of the object receives a pressure equal to the hydraulic pressure and is uniformly compressed, and a green compact with a uniform density can be obtained.
In the present invention, the In-based cylindrical target can be integrally formed without using a bonding material by compressing and molding a metal powder for a target material having In as a component composition into a cylindrical backing tube. The In-based cylindrical target material used in the rotating state can be reliably held.

The manufacturing method of the In type | system | group cylindrical sputtering target of this invention is good to have a target material cutting process which cuts the said compacting body after the said compacting process.
Since the green compact formed by compression molding can be easily cut, an In-based cylindrical target material having a predetermined shape can be easily formed. For example, by removing both ends of the green compact and projecting the cylindrical backing tube from both ends of the In system cylindrical target material, the In system cylindrical target can be efficiently held in the sputtering apparatus. Can be manufactured.

In the method for producing an In-based cylindrical sputtering target of the present invention, the metal powder for a target material has a maximum particle size of 500 μm or less, and contains In: 40 to 60 mass%, Ga: 1 to 45 mass%, The balance is a component composition made of Cu.
Since the metal powder for a target material having such properties has low hardness, a cylindrical sputtering target can be satisfactorily manufactured by compression molding using a cold isostatic pressing method.
When the average particle diameter exceeds 500 μm, the surface irregularities increase with the consumption of the In-based cylindrical target material during use (during sputtering), and the micro arc discharge tends to increase.

The manufacturing method of the In type | system | group cylindrical sputtering target of this invention is good to have a roughening process of roughening the outer peripheral surface of the said cylindrical backing tube before the said compacting process.
Before the In-based cylindrical target material is compression molded, the adhesion of the In-based cylindrical target material can be improved by roughening the outer peripheral surface of the cylindrical backing tube in advance.

  Further, the present invention provides an In-based cylindrical sputtering material in which an In-based cylindrical target material containing In is formed in close contact so as to surround the outer peripheral surface of a cylindrical backing tube protruding from both ends of the In-based cylindrical target. The In-type cylindrical target material is a green compact having a relative density of 97% or more.

  According to the present invention, the In-based cylindrical target material and the cylindrical backing tube can be easily and reliably integrated, and the In-based cylindrical target material can be securely held during use, thereby improving the use efficiency. it can.

It is sectional drawing which shows the compacting process in the manufacturing method of the In type | system | group cylindrical sputtering target which concerns on this invention. It is sectional drawing which shows the In type | system | group cylindrical sputtering target which concerns on this invention.

Hereinafter, embodiments of an In-based cylindrical sputtering target and a method for producing the same according to the present invention will be described.
As shown in FIG. 2, an In-based cylindrical sputtering target 10 manufactured by the method for manufacturing an In-based cylindrical sputtering target according to this embodiment includes an In-based cylindrical target material (hereinafter referred to as “target material”). And an In-based cylindrical backing tube (hereinafter referred to as “backing tube”) 40 that protrudes from both ends of the target material 20 and is joined to the inner peripheral surface 21 of the target material 20.

The target material 20 has In as a component composition, and is made of In or an In alloy (In—Cu—Ga or In—Cu). The size (dimensions) of the target material 20 is not particularly limited. For example, the target material 20 is a cylindrical member having an outer diameter of 158 mm, a thickness of 25 mm, and a length of 2000 mm. The material and dimensions of the backing tube 40 are not particularly limited. For example, the backing tube 40 is made of Ti or SUS, and is a cylindrical member having an outer diameter of 133 mm, a thickness of 8 mm, and a length of 2040 mm.
Thus, the target material 20 and the backing tube 40 constituting the cylindrical sputtering target 10 are directly joined without using a bonding material or the like.

Next, a method for manufacturing the cylindrical sputtering target 10 by forming the target material 20 on the outer peripheral surface 41 of the backing tube 40 will be described.
The In-based cylindrical sputtering target 10 is compression-molded by a cold isostatic pressing method in a state in which a metal powder for a target material having In as a component composition is closely attached so as to surround the outer peripheral surface 41 of the backing tube 40, It is manufactured by forming the target material 20 having a relative density of 97% or more on the outer peripheral surface 41.

  The target material metal powder as the raw material of the target material 20 is produced by gas atomization and sieving, and has an average particle diameter of 500 μm or less, containing In: 40 to 60 mass%, Ga: 1 to 45 mass%, The balance is a component composition made of Cu. The reason why the average particle diameter is 500 μm or less is that when the average particle diameter exceeds 500 μm, the surface irregularities increase with the consumption of the target material 20 during use (during sputtering), and the micro arc discharge tends to increase. Because there is.

(Roughening process)
First, the outer peripheral surface 41 is roughened in advance by blasting the outer peripheral surface 41 of the backing tube 40 to which the target material 20 is bonded using alumina particles. Thereby, the adhesiveness of the target material formed later and the backing tube 40 can be improved.

(Green compaction process)
Next, the target material metal powder 22 is compression-molded in a state of being in close contact with the outer peripheral surface 41 of the cylindrical backing tube 40, whereby an In-based target material having a relative density of 97% or more is formed on the outer peripheral surface 41. The green compact is formed in close contact. In the present embodiment, the target material 20 is compressed and formed on the outer peripheral surface 41 of the backing tube 40 by using the external pressure-type pressurizing apparatus 100 shown in FIG. To integrate.

The cold isostatic pressing method is a compression molding method in which isotropic pressure is applied to a target object (metal powder 22 for a target material) using liquid pressure, such as pressing using a mold. In addition, since there is no friction with the metal and isotropic pressure is applied, the surface of the object is uniformly compressed by receiving a pressure equal to the hydraulic pressure to obtain a green compact with a uniform density. be able to.
In the pressurizing apparatus 100, the metal powder 22 for target material is sealed in a molding die (rubber die) 15 having a low deformation resistance such as a rubber bag, and compression molding is performed by applying hydraulic pressure thereto.

Specifically, after filling the rubber mold 15 with the target material metal powder 22 and the backing tube 40 outside the high-pressure container 11 and sealing, the rubber mold 15 is directly immersed in the pressure medium 14 in the high-pressure container 11, Molding is performed by applying a uniform hydraulic pressure to the outer surface of the rubber mold 15 at a temperature of 100 ° C. or lower and a pressure of 0.5 to ² ton / cm ² (49 to 196 MPa). At this time, the backing tube 40 is sealed with rubber separator plugs 42 at both ends before being put into the rubber mold 15 and sealed with sand 43 inside. Keep it.
Although not shown, the pressurizing apparatus 100 shown in FIG. 1 is provided with a hydraulic pressure boosting unit independently of the high-pressure vessel 11, and is added by pushing the pressure medium 14 into the high-pressure vessel 11 from the outside. Can be pressed. Moreover, the code | symbol 12 shown in FIG. 1 is the upper cover which seals the upper end of the high pressure vessel 11, and the code | symbol 13 is the lower cover which seals the lower end of the high pressure vessel 11.

  And after forming the green compact which shape | molded the metal powder 22 for target materials in the backing tube 40 according to the said compacting process, the backing tube 40 and green compact which were mutually joined are taken out from the pressurization apparatus 100, Unnecessary separator plugs 42 and sand 43 are removed.

(Target material cutting process)
As shown in FIG. 2, the green compact is cut so that both end portions of the backing tube 40 protrude from both ends of the target material 20 with an arbitrary length, and both end portions of the target material 20 are removed. Thereby, the In type | system | group cylindrical sputtering target 10 provided with the target material 20 and the backing tube 40 which protrudes and is provided from the both ends of the target material 20 is obtained.
In addition, when processing the both ends of the target material 20, the surface of the target material 20 can also be processed and formed in predetermined thickness.

As described above, according to the manufacturing method of the In-based cylindrical sputtering target of the present embodiment, the metal powder for target material is directly compression-molded on the backing tube 40, so that the target material 20 (compact powder) can be used without using a bonding material. Body) can be formed in close contact with the backing tube 40. For this reason, the target material 20 used in a rotating state can be reliably held.
Moreover, since the green compact formed by compression molding can be easily cut, a target material having a predetermined shape can be easily formed. For this reason, as in the above-described embodiment, by allowing the backing tube 40 to protrude from both ends of the target material 20, the In-based cylindrical sputtering target 10 can be reliably held in the sputtering apparatus, and the entire surface of the target material 20 can be retained. It can be used efficiently.

In addition, this invention is not limited to the thing of the structure of the said embodiment, In a detailed structure, it is possible to add a various change in the range which does not deviate from the meaning of this invention.
For example, in the above-described embodiment, the target material 20 is compression-molded using the external pressure-type pressurizing apparatus 100 using the cold isostatic pressure method, but the present invention is not limited to this. For example, another cold isostatic pressurization method such as a piston direct pressure type in which a piston is provided in place of the upper lid 12 and a pressure medium in the high-pressure vessel 11 is compressed and pressurized by the piston may be employed. In addition to the cold isostatic pressing method, compression molding can also be performed by a press device.

DESCRIPTION OF SYMBOLS 10 In type cylindrical sputtering target 11 High pressure vessel 12 Upper lid 13 Lower lid 14 Pressure medium 15 Rubber mold (molding mold)
20 Target material (In-based cylindrical target material)
21 inner peripheral surface 22 metal powder for target material 40 backing tube (cylindrical backing tube)
41 Outer peripheral surface 42 Separator plug 43 Sand 100 External pressurizing device

Claims (5)

  A manufacturing method of an In-based cylindrical sputtering target in which an In-based cylindrical target material containing In is joined to an outer peripheral surface of a cylindrical backing tube, wherein the metal powder for a target material having In as a component composition is the cylindrical shape Compaction molding in which a compact with a relative density of 97% or more is formed in close contact with the outer peripheral surface by compression molding using the cold isostatic pressing method in close contact with the outer peripheral surface of the backing tube A method for producing an In-based cylindrical sputtering target, comprising forming the In-based cylindrical target material on an outer peripheral surface of the cylindrical backing tube by a process.   The method for producing an In-based cylindrical sputtering target according to claim 1, further comprising a target material cutting step of cutting the green compact after the green compacting step.   The metal powder for target material has a maximum particle size of 500 μm or less, contains In: 40 to 60% by mass, Ga: 1 to 45% by mass, and the balance is made of Cu. The manufacturing method of the In type | system | group cylindrical sputtering target of Claim 1 or 2 to do.   The In series cylindrical sputtering according to any one of claims 1 to 3, further comprising a roughening step of roughening an outer peripheral surface of the cylindrical backing tube before the compacting step. Target manufacturing method.   An In-based cylindrical sputtering target in which an In-based cylindrical target material containing In is formed in close contact so as to surround an outer peripheral surface of a cylindrical backing tube protruding from both ends of the In-based cylindrical target. An In-based cylindrical sputtering target, wherein the cylindrical target material is a green compact having a relative density of 97% or more.

Images