JP2012046807A - Hollow target assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hollow sputtering target assembly having satisfactory adhesion between a supporting tube and a target body.SOLUTION: The hollow target assembly is composed of a supporting tube 1, target bodies 20, 21 and 25 and a plurality of elastic elements 3. The elastic elements are arranged so as to be biased in the space of grooves 23 formed on the inner wall of a hollow target material and recesses 12 formed on the outer peripheral wall of the supporting tube so that it is possible to closely adhere the target body with the supporting tube by a simple and inexpensive method.

Description

  The present invention relates to a sputtering target assembly, and more particularly to a hollow target assembly using elastic elements to provide good adhesion between a support tube and a target body.

  The sputtering efficiency of conventional planar targets is only 15% to 40%, so that planar targets are not suitable for wide area deposition. Since the sputtering efficiency of the rotating target can be increased from 70% to 90%, the rotating target is widely used for the deposition of a large area instead of the planar target in order to reduce the cost.

  A rotating target usually consists of a target body and a support tube. The target body covers the outer peripheral surface of the support tube. The target body generates a large amount of heat during the deposition, and the heat needs to be guided to the cooling medium via the support tube. Therefore, sufficient contact area between the support tube and the target body is necessary to provide good heat conduction. Conventionally, a metal having a low melting point is filled in the gap between the target body and the support tube so that they can make good contact with each other. However, the cost of the low melting point metal is too high, and the inner surface of the target body and the outer surface of the support tube need to be further metallized. In addition, cracks may occur between the target body and the support tube during the deposition and cooling process because they have different coefficients of thermal expansion.

  In order to solve the above-mentioned problem, US Patent Application Publication No. 2008/0003385 and International Publication No. 2009/036910 have at least an interface between a support tube and a target body, as shown in FIG. A support tube is disclosed that includes an interlocking portion that is either convex or concave. The target body is attached to the support tube by heat treatment or casting. However, equipment for heat treatment is expensive, thereby increasing manufacturing costs. Furthermore, if the difference in the coefficient of thermal expansion between the support tube and the target body is too large and too much stress is applied to the meshing portion, cracking and peeling may occur. When a casting technique is used to form the target body, a high casting temperature and a long cooling time cause a decrease in the density of the target body and a non-uniform microstructure of the target body, so that the quality of the deposited film is not good.

  US Patent Application Publication No. 2009/0152108 discloses a target arrangement that uses elastic elements to overcome the gap formed between the support tube and the target body, as shown in FIG. However, the support tube and the target body are attached to each other by friction of elastic elements. If insufficient elastic elements are used, the friction provided by the elastic elements will be insufficient to prevent the target body from moving. It is a very complicated technique how to put enough elastic elements in the gap between the support tube and the target body.

US Patent Application Publication No. 2008/0003385 International Publication No. 2009/036910 US Patent Application Publication No. 2009/0152108

  An object of the present invention is to provide a hollow target assembly capable of improving the disadvantages of high cost, complicated processes, poor contact between the target body and the support tube, and poor quality of the deposited film due to the target material. .

In order to achieve the aforementioned object, the present invention provides:
A support tube having a distal end and a distal end, and a recess formed on the outer surface at a position near the distal end and the distal end, and
At least a first hollow target material, a second hollow target material, and grooves formed on the inner surfaces of the first and second target materials from one end thereof in the axial direction, respectively. A target body having an opening formed at the end of the second target material;
A plurality of elastic members, and spaces are formed by the grooves on the inner surfaces of the first and second hollow target materials and the corresponding recesses at the tip and end of the support tube, and one space is formed in each space. The first and second hollow target materials sequentially cover the outer peripheral surface of the support tube, and the first and second target materials face the tip and the end, respectively, so that the elements are placed biased. Then open,
A hollow target assembly is provided.

  Preferably, the target body further includes at least one third hollow target material, and the third hollow target material is placed between the first and second target materials. In the third target material, a groove is formed on the inner surface from one end to the axial direction, and a corresponding recess is formed on the outer surface of the support tube, and the elastic member is formed by the groove and the corresponding recess. Is placed in the space.

  Preferably, in the first hollow target material, a groove is formed at an adjacent end to the third hollow target material in the axial direction, and the elastic element is formed by a recess corresponding to the groove. Corresponding recesses are formed in the outer surface of the support tube so as to be put into the space to be formed.

  Preferably, the elastic element is an elastic sheet, one end of which is placed in the groove and the other end is placed in the corresponding recess. In one embodiment, the grooves of the first, second and third target materials each form a continuous ring, and the recess of the support tube forms a continuous ring. In another embodiment, the grooves of the first, second and third target materials each form an intermittent ring, and the recess of the support tube forms an intermittent ring.

  Preferably, the elastic element is a spring, and both ends thereof respectively contact the bottom of the recess corresponding to the bottom of the groove. In one embodiment, the grooves of the first, second and third target materials each form an intermittent ring, and the recess of the support tube forms a continuous ring.

1 is a cross-sectional view of a first preferred embodiment of the hollow target assembly of the present invention; Figure 2 is a cross-sectional view of a second preferred embodiment of the hollow target assembly of the present invention; FIG. 4 is a cross-sectional view of a third preferred embodiment of the hollow target assembly of the present invention; FIG. 6 is a cross-sectional view of a fourth preferred embodiment of the hollow target assembly of the present invention; FIG. 6 is a plan view of a fifth preferred embodiment of the hollow target assembly of the present invention; FIG. 6 is a plan view of a sixth preferred embodiment of the hollow target assembly of the present invention; It is a cross-sectional view of one hollow target with the prior art, FIG. 6 is a cross-sectional view of another hollow target in the prior art.

  The above and other technical features and advantages of the present invention will be described in more detail with reference to the drawings.

  In order to reduce the manufacturing cost of the rotating target material and to improve the contact between the support tube and the target body, the present invention comprises one support tube 1 and one target as shown in FIG. A hollow target assembly comprising a body 2 and a plurality of elastic elements 3 is provided.

  The support tube 1 includes a distal end 10 and a distal end 11. A recess 12 is formed on the outer surface of the support tube 1 at a position close to the distal end 10 and the distal end 11 respectively. The recess 12 is formed in a continuous ring by machining, and the cross-sectional shape of the recess 12 may be a rectangle, a triangle, or any other shape.

  The target body 2 includes a first hollow target material 20 and a second hollow target material 21. The grooves 23 are formed on the inner surfaces of the first hollow target material 20 and the second hollow target material 21, respectively, so that the openings 24 are formed in the first hollow target material 20 and the second hollow target material 21, respectively. It is formed from one end 22 of the target material over the axial direction. The first and second hollow target materials 20 and 21 sequentially cover the outer peripheral surface of the support tube 1 sequentially, and the opening 24 of the first and second hollow target materials 20 and 21 is the tip 10 of the support tube 1. And the distal end 11, and the space 4 includes a groove 23 on the inner surface of the first and second hollow target materials 20, 21, and a corresponding recess 12 on the outer surface of the distal end 10 of the support tube 1 and the distal end 11. Is formed by.

  The elastic element 3 is biased from the opening 24 to the first and second hollow target materials 20 and 21 and is disposed in the space 4 formed by the groove 23 and the corresponding recess 12. The support tube 1 and the target body 2 are closely coupled by these elastic elements 3.

  After the first hollow target material 20 is passed through and covers the support tube 1 and the elastic element 3 is placed in the space 4 formed by the groove 23 and the corresponding recess 12, the first hollow target material 20 The target material 20 is heated to the melting point of the metal. The molten metal is poured into the gap between the support tube 1 and the first hollow target material 20. The heat source is removed, and the temperature of the first hollow target material 20 gradually decreases, so that the molten metal hardens. As a result, the first hollow target material 20 and the support tube 1 can adhere to each other well. . Thereafter, the second hollow target material 21 is processed in the same way so as to adhere well to the support tube 1. In this regard, different thermal expansions between the support tube 1, the target body 2 and the metal will create voids between the support tube 1 and the target body 2 during the precipitation or cooling process, but the elastic element 3. , The mutual adhesion between the support tube 1 and the target body 2 can be maintained, and the target body 2 does not move.

  Preferably, the metal is a metal having a low melting point. More preferably, the metal is indium.

  As shown in FIGS. 1 and 4, the target main body 2 further includes at least a third hollow target material 25 between the first hollow target material 20 and the second hollow target material 21. First, the first hollow target material 20 covers the outer peripheral surface of the support tube 1 and remains fixed by the use of the elastic element 3. Next, the third hollow target material 25 is passed through the support tube 1. Finally, the second hollow target material 21 is passed through the support tube 1 and remains fixed by the use of the elastic element 3. The total amount of the third hollow target material 25 can be changed depending on the length of the support tube 1. Since the first and second hollow target materials 20, 21 remain in a fixed position by the elastic element 3, the third hollow target material 25 also has a target body 2 between the first and second hollow target materials 20, 21. Stays fixed in the middle.

  As shown in FIG. 2, the third hollow target material 25 is also formed with a groove 23 on the inner surface from one end 22 to the axial direction. Corresponding recesses 12 are also formed in the outer peripheral surface of the support tube 1. When the third hollow target material 25 is passed through the support tube 1, the one end 22 having the groove 23 faces the end 11 of the support tube 1. In this regard, the first, second and third hollow target materials 20, 21, 25 have a groove 23 for placing the elastic element 3, and thus provide a more efficient thermal conductivity. In addition, the adhesion between the target body 2 and the support tube 1 is enhanced.

  During assembly, the first hollow target material 20 is passed through the support tube 1 and the elastic element 3 is arranged in the space 4. Molten metal is poured into the gap between the support tube 1 and the first hollow target material 20. After the liquid metal is solidified, the third and second hollow target materials 25 and 21 are continuously passed through the support tube 1 in the same manner. That is, when each of the third and second hollow target materials 25 and 21 is passed through the support tube 1, the elastic element 3 is placed in the space 4 formed by the corresponding recess 12 of the support tube. Thereafter, the molten metal is poured into the gap between the hollow target material and the support tube 1 and cooled, and the next third or second hollow target material 25, 21 is processed in the same manner as described above. Is passed through the support tube 1.

  As shown in FIG. 3, a groove 23 is further formed on the inner surface of the first hollow target material 20 from the other end over the axial direction. A recess 12 is also formed in the outer surface of the support tube 1 at a corresponding position. The elastic element 3 is placed in a space 4 formed by the groove 23 and the corresponding recess 12 in order to increase the adhesion between the target body 2 and the support tube 1.

  The groove 23 of the target material provides a space for arranging the elastic element 3. However, the groove 23 should be as small as possible during the treatment to prevent impact to the target material and to increase the area of use of the target material. In order to provide sufficient resistance and prevent displacement of the elastic element 3, the circumferential depth of the recess 12, if not as great as the thickness of the elastic element 3.

  As shown in FIGS. 1 to 3, the elastic element 3 is preferably a sheet having a bent elasticity. When the elastic element 3 is a sheet having elasticity, the depth of the groove 23 in the axial direction of the target material is larger than the distance from the end of the recess 12 to the closest end of the support tube 1. Therefore, one end of the elastic element 3 is placed in the groove 23 and the other end of the elastic element 3 is placed in the corresponding recess 12.

  As shown in FIG. 4, the elastic element 3 is preferably a spring. When the elastic element 3 is a spring, both ends of the spring come into contact with the groove 23 and the bottom of the corresponding recess 12 respectively.

  The elastic element 3 preferably has good strength for supporting the target material. The elastic element 3 preferably has good conductivity for conducting heat from the target body 2 to the support tube 1. Preferably, the elastic element 3 is made from pure copper.

  As shown in FIG. 5, the groove 23 of the target material can be made as a continuous ring by machining. The groove 23 can also be made as an intermittent ring (ie, multiple grooves), as shown in FIG.

Example Aluminum zinc oxide is chosen as the sputtering material to form the target body 2. The target body 2 includes one first hollow target material 20, one second hollow target material 21, and three third hollow target materials 25. The three types of hollow target materials have an outer diameter and an inner diameter of 160 mm and 133 mm, respectively. Each length of the target material in the axial direction is 280 mm, and as a result, the total length of the target body 2 is 1400 mm. The groove 23 has a depth of 10 mm in the axial direction and 2 mm in the circumferential direction by machining the inner surface of the target member from one end 22 of the first hollow target material 20 and the second hollow target material. It is made as a continuous ring with a thickness. The support tube 1 is made of stainless steel SUS304. The outer diameter and inner diameter of the lining tube 1 are 132.5 mm and 125 mm, respectively. The length of the support tube 1 is 1450 mm. The outer diameter of the support tube 1 is 0.5 mm smaller than the inner diameter of the target body 2 so that the target body 2 can easily cover the peripheral surface of the support tube 1. The recess 12 is made by machining from the position near the tip 10 and the end 11 to the outer surface of the support tube 1. The recess 12 has a triangular cross-sectional shape, and has a length of 3 mm in the axial direction and a depth of 1 mm in the circumferential direction. The elastic element 3 is made of pure copper having a thickness of 1 mm. The outer surfaces of the first, second and third hollow target materials 20, 21 and 25 and the inner surface of the support tube 1 are metal-coated by a preliminary treatment with molten indium.

  The first hollow target material 20 is passed through the support tube 1 and six elastic elements are placed in the space formed by the groove 23 and the corresponding recess 12. Since the heating blanket is used to cover the first hollow target material 20 and the temperature is maintained at 180 ° C. for 30 minutes, the temperature of the first hollow target material 20 is maintained higher than the melting point of indium. The molten indium is poured into the space between the first hollow target material 20 and the support tube 1. The heated blanket is removed and the molten indium is gradually solidified. Thereafter, three third hollow target materials 25 and a second hollow target material 21 are sequentially passed through the support tube 1, and the elastic element 3 is inserted into the space formed by the groove 23 and the corresponding recess 12. The step of placing and filling the gap between the target material and the support tube 1 with molten indium is repeated after passing each hollow target material through the support tube 1.

  Finally, the hollow target assembly of the present invention uses a space 4 for the placement of the elastic element 3 formed by the groove 23 on the outer surface of the target material and the corresponding recess 12 on the outer surface of the support tube 1. To do. The elastic element 3 not only provides good heat conduction, but also provides good adhesion between the target body 2 and the support tube 1.

  What has been described above are merely preferred embodiments of the present invention, which are illustrative only and not limiting. Many modifications, improvements or equivalents may be made by those skilled in the art without departing from the spirit of the invention and the scope of the claims, as defined by the claims. It will fall within the protection scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Support pipe 2 Target body 3 Elastic element 4 Space 10 Tip 11 End 12 Recess 20 First hollow target material 21 Second hollow target material 23 Groove 24 Opening 25 Third hollow target material

Claims (8)

A support tube having a distal end and a distal end, and a recess formed on the outer surface at a position near the distal end and the distal end, and
At least a first hollow target material, a second hollow target material, and grooves formed on the inner surfaces of the first and second hollow target materials from one end thereof in the axial direction, respectively, And a target body having an opening formed at the end of the second target material;
A plurality of elastic members, and spaces are formed by the grooves on the inner surfaces of the first and second hollow target materials and the corresponding recesses at the tip and end of the support tube, and one space is formed in each space. The first and second hollow target materials sequentially cover the outer peripheral surface of the support tube, and the first and second target materials face the tip and the end, respectively, so that the elements are placed biased. A hollow target assembly that opens.   The hollow according to claim 1, wherein the target body further includes at least one third hollow target material, the third hollow target material being placed between the first and second target materials. Target assembly.   In the third target material, a groove is formed on the inner surface from one end to the axial direction, and a corresponding recess is formed on the outer surface of the support tube, and the elastic member is formed by the groove and the corresponding recess. The hollow target assembly according to claim 2, wherein the hollow target assembly is placed in the formed space.   In the first hollow target material, a groove is formed at the proximal end to the third hollow target material in the axial direction, and a corresponding recess is formed in the outer surface of the support tube. The hollow target assembly according to claim 3, wherein the elastic element is placed in the space formed by the groove and a corresponding recess.   The hollow target assembly according to any one of claims 1 to 4, wherein the elastic element is an elastic sheet, one end of which is placed in the groove and the other end is placed in the corresponding recess. .   The hollow target assembly according to any one of claims 1 to 4, wherein the elastic element is a spring, and both ends thereof respectively contact the bottom of the groove and the bottom of the corresponding recess.   6. The groove according to claim 1, wherein the grooves of the first, second, and third target materials each form a continuous ring, and the recess of the support tube forms a continuous ring. The hollow target assembly as described.   7. The groove according to claim 1, wherein the grooves of the first, second, and third target materials each form an intermittent ring, and the recess of the support tube forms a continuous ring. The hollow target assembly according to Item.

Images