JP2011068946A - Rotary target assembly and rotary target - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary target assembly forming a rotary target in which a cylindrical target and a cylindrical supporting pipe are firmly combined. <P>SOLUTION: The rotary target assembly includes a cylindrical target and a cylindrical supporting pipe. The difference between the inside diameter of the cylindrical target and the outside diameter of the cylindrical supporting pipe is substantially equal to a value obtained by multiplying the yield strain of the target material by the inside diameter of the cylindrical target and N. In this case, the N is a value in the range from 1 to 10. The difference can be adjusted by the dimensions of the target material and the cylindrical target, and, as a result, the cylindrical target can be firmly bonded to the cylindrical supporting pipe. In this way, the thermal conductivity and electric conductivity of the rotary target improve. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotating target, and more particularly, to a rotating target having a cylindrical target and a cylindrical support tube firmly coupled to the cylindrical target.

  In general, a planar target is used in the magnetron sputtering method. Sputtering is performed on the surface of the target and concentrates the portion of the highest plasma density where the magnetic field lines are in contact with the target surface. For this reason, a racetrack-like erosion pattern is formed on the surface of the target after sputtering. The planar target has a usage rate of about 35% to 50%.

  For this reason, the usage rate of the rotating target is 70% to 80% at the maximum in order to reduce the cost of sputtering, and has a long life.

  The rotating target has a cylindrical target and a cylindrical support tube. Target binding for rotating targets is more complex than target binding for planar targets. Conventional methods include providing a cylindrical target and the cylindrical support tube having an outer diameter smaller than the inner diameter of the cylindrical target, inserting the cylindrical support tube into the cylindrical target, and the cylinder Applying a solder made of a low-melting metal to a gap between the cylindrical target and the cylindrical support tube to bond the shaped target and the cylindrical support tube. When soldering the cylindrical target and the cylindrical support tube, it is difficult to apply pressure to the rotating target, and as a result, the cylindrical target cannot be firmly bonded to the cylindrical support tube.

  Japanese Patent Application Laid-Open No. 11-071667 discloses a mechanical force for inserting the cylindrical support tube into the cylindrical target according to the theory of thermal expansion and contraction and for coupling the cylindrical support tube and the cylindrical target. Disclosed is a method of manufacturing a rotating target that includes using. The difference between the inner diameter of the cylindrical target and the outer diameter of the cylindrical support tube is from 0.01 mm to 0.5 mm, but the relationship between the difference and the dimensions of the rotating target is completely taken into account. Not. George M.M. According to Wityak's Research (Society of Vacuum Coats, 49th Annual Technical Conference Processings, 2005), the difference and dimensions of the rotating target are not properly adjusted, and the cylindrical target and the cylindrical support tube are removed. In spite of this, it can be found that the rotating target has a low thermal conductivity and conductivity in proportion to the temperature change of the rotating target and the frequency of occurrence of the electric arc.

Japanese Patent Laid-Open No. 11-071667 George M.M. Wityak's Research, Society of Vacuum Coators, 49th Annual Technical Conference Processings, 2005

  A main object of the present invention is to provide a rotating target assembly that forms a rotating target in which a cylindrical target and a cylindrical support tube are firmly coupled.

  In order to solve the above-mentioned object, a rotating target assembly according to the present invention includes a cylindrical target and a cylindrical support tube. The difference between the inner diameter of the cylindrical target and the outer diameter of the cylindrical support tube is substantially equal to the yield strain of the target material multiplied by the inner diameter and N of the cylindrical target. Here, N is a value between 1 and 10.

  The difference can be adjusted by the target material and the dimensions of the cylindrical target, and as a result, the cylindrical target can be firmly bonded to a cylindrical support tube. Therefore, the thermal conductivity and conductivity of the rotating target are improved.

The expanded view of the rotation target assembly which concerns on this invention. The end view of the cylindrical support tube of the rotation target assembly which concerns on this invention. 1 is an end view of a cylindrical target of a rotating target assembly according to the present invention. FIG. The disassembled perspective view of the Example of the rotation target assembly which concerns on this invention. The disassembled perspective view of another Example of the rotation target assembly which concerns on this invention.

  Referring to FIG. 1, the rotating target assembly according to the present invention includes a cylindrical target (10) and a cylindrical support tube (20). The cylindrical target (10) functions as an outer tube, is made of a target material, and has an inner diameter. The cylindrical support tube (20) functions as an inner tube, is used by being inserted into the cylindrical target (10), and has an outer diameter. The inner diameter of the cylindrical target (10) is smaller than the outer diameter of the cylindrical support tube (20). The difference between the inner diameter of the cylindrical target (10) and the outer diameter of the cylindrical support tube (20) is obtained by multiplying the yield strain of the target material by the inner diameter and N of the cylindrical target (10). Substantially equal. Here, N is a value between 1 and 10.

R represents the inner diameter of the cylindrical target (10), r represents the outer diameter of the cylindrical support tube (20), and r is larger than R. When heated, there is a temperature difference between the cylindrical target (10) and the cylindrical support tube (20). According to the theory of thermal expansion and contraction, R ′ is substantially equal to R (1 + K _a T _a ) and r ′ is substantially equal to r (1 + K _b T _b ). R ′ represents the inner diameter of the cylindrical target after deformation of the cylindrical target (10), and r ′ represents the outer diameter of the cylindrical support tube after deformation of the cylindrical support tube (20). . K _a indicates the thermal expansion coefficient of the cylindrical target (10), and K _b indicates the thermal expansion coefficient of the cylindrical support tube (20). T _a indicates the temperature difference of the temperature of the cylindrical target (10) before and after expansion or contraction, and T _b indicates the temperature difference of the temperature of the cylindrical support tube (20) before and after expansion or contraction. When R ′ is greater than r ′, the cylindrical support tube (20) can be inserted into the cylindrical target (10).

  The difference between the inner diameter of the cylindrical target (10) and the outer diameter of the cylindrical support tube (20) is due to the robustness of the cylindrical target (10) and the cylindrical support tube (20) and the cylindrical target (10). ) And the stress that the cylindrical support tube (20) can withstand.

  The preferred difference of the present invention should be substantially equal to the yield strain of the target material multiplied by the inner diameter and N of the target material. Here, N is a value between 1 and 10. When the difference is less than the preferred difference, the resulting rotating target has low thermal conductivity and conductivity, resulting in an undesirably elevated temperature during sputtering and abnormal discharge. When the difference is greater than the preferred difference, the rotating target is deformed, damaged and cannot be used.

  The cylindrical target (10) and the cylindrical support tube (20) can be firmly bonded without any soldering. Furthermore, in order to improve the thermal conductivity, conductivity and the coupling between the cylindrical target (10) and the cylindrical support tube (20), the intermediate is the inner surface of the cylindrical target (10) and the cylindrical support tube ( 20) and the outer surface.

  Referring to FIGS. 2 and 3, the cylindrical target (10) comprises at least one inner groove (12) formed in the inner surface (11), the inner groove being filled with an intermediate body (30). It may be. The cylindrical support tube (20) comprises at least one outer groove (22) formed in the outer surface (21), which outer groove may be filled with an intermediate body (30). The intermediate body (30) is made of a conductive material and is attached to the inner groove (12) and / or the outer groove (22) before and after assembly of the cylindrical target (10) and the cylindrical support tube (20). Can do.

  Referring to FIG. 4, in one embodiment, the cylindrical target (10) comprises a proximal end (13) and a distal end (14). The inner groove (12) is formed in the inner surface (11) adjacent to the proximal end (13) or the distal end (14). The cylindrical support tube (20) comprises a proximal end (23) and a distal end (24). An outer groove (22) is formed in the outer surface (21) adjacent to the proximal end (23) or the distal end (24), respectively. The grooves (12), (22) may be formed at intervals or may be communicated with each other by forming an annular groove. Referring to FIG. 5, in another embodiment, each inner groove (12 ') or outer groove (22') is a longitudinal groove from the proximal end to the distal end. Each groove may be straight, spiral or the like.

  The present invention provides a rotating target including a rotating target assembly. The cylindrical support tube (20) is attached to the cylindrical target (10) and is firmly coupled to the cylindrical target.

[Example]
[Method of manufacturing rotating target]
[Example 1]
A silver cylindrical target having an inner diameter of 132.5 mm and a stainless steel cylindrical support tube having an outer diameter of 133.0 mm are provided. The coefficient of thermal expansion of silver is about 19.5 × 10 ⁻⁶ / K. The silver cylindrical target is heated from 25 ° C. to 500 ° C., and the inner diameter is expanded to 133.7 mm. The stainless steel cylindrical support tube is at 25 ° C., and the support tube is inserted into the silver cylindrical target to form a rotating target. The rotating target is cooled to room temperature and assembled. The difference between the silver cylindrical target and the stainless steel cylindrical support tube is 0.5 mm, the yield strain of silver is 0.25%, and N is 1.5.

[Example 2]
A cylindrical target of indium tin oxide having an inner diameter of 70.0 mm and a stainless steel cylindrical support tube having an outer diameter of 70.15 mm are provided. The thermal expansion coefficient of indium tin oxide is about 7.5 × 10 ⁻⁶ / K, and the thermal expansion coefficient of stainless steel is about 10.5 × 10 ⁻⁶ / K. The indium tin oxide cylindrical target is heated from 25 ° C. to 525 ° C. and the inner diameter is expanded to 70.26 mm. The stainless steel cylindrical support tube is cooled from 25 ° C. to −75 ° C., and the outer diameter of the stainless steel cylindrical support tube is reduced to 70.08 mm. The stainless steel cylindrical support tube is inserted into the indium tin oxide cylindrical target to form a rotating target. The rotating target is cooled to room temperature and assembled. The difference between the indium tin oxide cylindrical target and the stainless steel cylindrical support tube is 0.15 mm, the yield strain of indium tin oxide is 0.21%, and N is 1.0. It is.

[Example 3]
An aluminum cylindrical target having an inner diameter of 100.0 mm and a stainless steel cylindrical support tube having an outer diameter of 101.0 mm are provided. The coefficient of thermal expansion of aluminum is about 23.2 × 10 ⁻⁶ / K. The aluminum cylindrical target is heated from 25 ° C. to 525 ° C. and the inner diameter is increased to 101.2 mm. The stainless steel cylindrical support tube is at 25 ° C., and the support tube is inserted into the aluminum cylindrical target to form a rotating target. The rotating target is cooled to room temperature and assembled. The difference between the aluminum cylindrical target and the stainless steel cylindrical support tube is 1.0 mm, the yield strain of aluminum is 0.21%, and N is 4.0.

[Comparative example]
A silver cylindrical target having an inner diameter of 132.6 mm and a stainless steel cylindrical support tube having an outer diameter of 132.8 mm are provided. The coefficient of thermal expansion of silver is about 19.5 × 10 ⁻⁶ / K. The silver cylindrical target is heated from 25 ° C. to 500 ° C., and the inner diameter is expanded to 133.8 mm. The stainless steel cylindrical support tube is at 25 ° C., and the support tube is inserted into the silver cylindrical target to form a rotating target. The rotating target is cooled to room temperature and assembled. The difference between the silver cylindrical target and the stainless steel cylindrical support tube is 0.2 mm, the silver yield strain is 0.25%, and N is 0.6.

[Sputtering test]
By adjusting the sputtering output from 1 kw to 5 kw, the temperature of the cylindrical targets of Examples 1, 2 and 3 is maintained at 50 ° C. while the temperature of the cylindrical target of the comparative example is higher than 150 ° C. ing. The bond of the comparative example proves to be not strong enough and as a result heat cannot be conducted from the cylindrical target to the cylindrical support tube. Accordingly, the difference between the inner diameter of the cylindrical target and the outer diameter of the cylindrical support tube is equal to the yield strain of the target material multiplied by the inner diameter and N of the cylindrical target. Must be controlled. N is a value between 1 and 10. The cylindrical target can be firmly coupled to a cylindrical support tube. Therefore, the thermal conductivity and conductivity of the rotating target are improved.

10 cylindrical target 11 inner surface 12, 12 'inner groove 13, 23 proximal end 14, 24 distal end 20 cylindrical support tube 21 outer surface 22, 22' outer groove 30 intermediate

Claims (5)

A cylindrical target that functions as an outer tube, consists of a target material, and has an inner surface and an inner diameter;
A cylindrical support tube that functions as an inner tube, is used inserted into the cylindrical target, and has an outer surface and an outer diameter larger than the inner diameter of the cylindrical target;
Before the cylindrical support tube is coupled to the cylindrical target, the difference between the inner diameter of the cylindrical target and the outer diameter of the cylindrical support tube is the yield strain of the target material in the cylinder. A rotating target assembly, substantially equal to the inner diameter of the target and N multiplied by N, where N is a value between 1 and 10.   The rotating target assembly of claim 1, further comprising at least one groove formed in each of the inner surface of the cylindrical target and / or the outer surface of the cylindrical support tube.   The rotating target assembly of claim 1, further comprising an intermediate body applied between the cylindrical target and the cylindrical support tube and made of a conductive material.   The rotary target assembly of claim 2, wherein the groove is filled with an intermediate made of a conductive material.   5. A rotating target comprising the rotating target assembly according to claim 1, wherein the cylindrical support tube is attached to and coupled to the cylindrical target.

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