Tubular target

Abstract

A target for a cathode sputtering system has a tubular target body made of a sputtering material and at least one connector piece, which is connected to the target body and projects from the target body, for attaching the target body to the cathode sputtering system. The target body is connected to the at least one connector piece in a vacuum-tight manner and the two are rotationally fixed relative to one another. At least one damper element is provided between the at least one connector piece and the target body.

Claims

1. A target for a cathode sputtering installation, the target comprising: a tubular target body formed of a sputtering material; at least one connector piece connected to said target body in a materially integral manner and protruding from said target body for connecting said target body to the cathode sputtering installation; said target body being connected to said at least one connector piece in a vacuum-tight manner and so as to be secured against twisting; and at least one damping element disposed between said at least one connector piece and said target body.

2. The target according to claim 1, wherein said at least one damping element is disposed between said target body and said at least one connector piece with said damping element being connected to each at least one surface of said target body and to at least one surface of said at least one connector piece.

3. The target according to claim 1, wherein at least one connection selected from the group consisting of said target body and said connector piece, said target body and said damping element, and said connector piece and said damping element is a materially integral connection.

4. The target according to claim 1, which comprises solder or adhesive disposed between at least one of said target body and said damping element or said connector piece and said damping element.

5. The target according to claim 1, wherein a thickness of said damping element in a radial direction lies between 0.25 and 5 mm.

6. The target according to claim 1, wherein said damping element has a coefficient of thermal expansion lying between a coefficient of thermal expansion of said target body and a coefficient of thermal expansion of said at least one connector piece.

7. The target according to claim 1, wherein said target body is composed of a material selected from the group consisting of molybdenum, a molybdenum-based alloy, titanium, a titanium-based alloy, copper and a copper alloy.

8. The target according to claim 1, wherein said connector piece and said damping element are disposed axially adjacent one another.

9. The target according to claim 1, wherein said at least one damping element is disposed radially adjacent at least one portion of said at least one connector piece.

10. The target according to claim 9, wherein said at least one damping element is disposed on an external face of said at least one connector piece.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) Exemplary embodiments of the invention will be discussed in more detail by means of the figures in which:

(2) FIG. 1 shows a schematic illustration of an end of a tube target in a sectional side view, according to a first design embodiment, wherein the connector piece (6a) and the damping element (4a) are disposed so as to be axially adjacent;

(3) FIG. 2-1 shows a schematic illustration of an end of a tube target in a sectional side view, according to a second design embodiment, wherein a damping element (4b) is disposed radially adjacent to a portion of the connector piece (6b);

(4) FIG. 2-2 shows a schematic illustration of an end of a tube target in a sectional side view, according to a further design embodiment, wherein a damping element (4b′) is disposed radially adjacent to a portion of the connector piece (6b); the axially inboard end region of the damping element (4b′) in this embodiment extends radially across at least a part-region of the connector piece (6b);

(5) FIG. 3 shows a schematic illustration of an end of a tube target in a sectional side view, according to a further design embodiment, wherein a damping element (4 c) is disposed radially adjacent to a portion of the connector piece (6 c); the damping element, when viewed in the tangential direction, has a cross section which contains a plurality of circular cross sections;

(6) FIG. 4-1 shows a schematic illustration of an end of a tube target in a sectional side view, according to a further design embodiment, wherein a damping element (4 d) is disposed radially adjacent to a portion of the connector piece (6 d); in this case the damping element is at least in part disposed on a radially inboard face of the connector piece (6 d), and only the axially inboard end region of the damping element is disposed between the connector piece (6 d) and the target body (2 d);

(7) FIG. 4-2 shows a schematic illustration of an end of a tube target in a sectional side view, according to a further design embodiment, wherein a damping element (4 d′) is disposed radially adjacent to a portion of the connector piece (6 d); in this case the damping element is at least in part disposed on a radially inboard face of the connector piece (6 d), and only the axially inboard end region of the damping element is disposed between the connector piece (6 d) and the target body (2 d); the axially inboard end region of the damping element (4 d′) in this embodiment extends radially across at least a part-region of the connector piece (6 d).

DESCRIPTION OF THE INVENTION

(8) FIGS. 1 to 4-2 show in each case schematic illustrations of an end of a tube target (1 a-d) in a sectional side view, according to various design embodiments; the tube targets (1 a-d) described may be symmetrically constructed, for example; such that the described elements of the illustrated end of the tube target (1 a-d) correspond to the elements at the opposite end (not illustrated) of the tube target (1 a-d); alternatively, the ends of the described tube targets may have ends of dissimilar designs.

(9) For example, a first end of the target (1 a-d) may be configured as is illustrated in one of the figures, and a second end of the target (1 a-d) may have a shape deviating therefrom, such as the shape of a cap, for example. Furthermore alternatively, a first end of a tube target (1 a-d) may be configured according to one of the design embodiments illustrated in

(10) FIGS. 1 to 4-2, and a second end of the tube target (1 a-d) may be configured according to another of the design embodiments illustrated in FIGS. 1 to 4-2.

(11) Both ends of the tube target are preferably symmetrically constructed.

(12) Alternatively, one end is configured as is illustrated in one of FIGS. 1 to 4-2, and the other end is provided with a cap.

(13) The effect of the damping element is particularly pronounced in one of the embodiments shown in FIG. 2-1, 2-2, or 3.

(14) Elements and properties which are common to the various design embodiments of the tube target (1 a-d) illustrated in FIGS. 1 to 4-2 will be first described hereunder.

(15) The tube targets (1 a-d) may be used in cathode sputtering installations such as magnetron sputtering installations, for example. The susceptibility to fracturing of a target and thus the service life thereof may be improved by the tube target (1 a-d) according to the invention.

(16) Crack formation may arise in the material of the target body, of the connector piece, or else of the optionally present adhesive or solder on account of the rotational stress of the target, the target in consequence having to be prematurely replaced. This crack formation may be reduced by means of the schematically illustrated tube target (1 a-d) such that the life span may be significantly extended.

(17) The illustrated targets (1 a-d) are so-called monolithic targets, that is to say that the target bodies (2 a-d) are manufactured completely from the sputtering material. Said target bodies (2 a-d) in particular do not have a (continuous) support tube onto which the sputtering material is soldered/brazed, for example (“bonded targets”).

(18) Each of the illustrated targets (1 a-d) has at least one connector piece (6 a-d) which protrudes from the target body (2 a-d) and serves for connecting the target body to a cathode sputtering installation. The target body is connected to this connector piece in a vacuum-tight manner. The target body (2 a-d) and the connector piece (6 a-d) are connected in a vacuum-tight manner by means of adhesive bonding or soldering/brazing, for example; one or a plurality of annular seals or O-rings may furthermore be optionally disposed between the two elements.

(19) The internal diameter of the at least one connector piece (6 a-c) preferably corresponds to the internal diameter of the target body (2 a-c) such that a flat or stepless transition, respectively, is provided between the two elements. In the case of the embodiment which is illustrated in FIG. 4-1 the internal diameter of the connector piece (6 d) in the region of the damping element (4 d) does not correspond to the internal diameter of the target body (2 d), but the radial extent of the damping element (4 d) is adapted in such a manner that the internal diameter of the damping element (4 d) corresponds to that of the target body (2 d).

(20) Each of the targets (1 a-d) illustrated thus furthermore has at least one damping element (4 a-d′). This damping element is disposed between the target body (2 a-d) and the connector piece (6 a-d).

(21) In the embodiments which are illustrated in FIGS. 1 to 4-2, the at least one damping element (4 a-d′) is disposed in an advantageous manner between the target body (2 a-d) and the at least one connector piece (6 a-d) such that said damping element is connected to at least each one face of the target body (2 a-d) and to at least one face of the at least one connector piece (6 a-d). In the case of the embodiments which are illustrated in FIGS. 4-1 and 4-2, the damping element is at least in part disposed on a radially inboard face of the connector piece (6 d), and only the axially inboard end region of the damping element (4 d and 4 d′) is disposed between the connector piece (6 d) and the target body (2 d). As is shown in FIG. 4-2, the axially inboard end region of the damping element (4 d′) may extend radially across at least a part-region of the connector piece (6 d).

(22) The target body (2 a-d) and the connector piece (6 a-d) may be interconnected in a materially integral manner. A solder or an adhesive may be additionally disposed between the target body (2 a-d) and the damping element (4 a-d′), and/or between the connector piece (6 a-d) and the damping element (4 a-d′).

(23) The individual elements (and the points of difference thereof) will be described in more detail hereunder with reference to the various design embodiments of the tube target (1 a-d) illustrated in the figures.

(24) FIG. 1 shows a first design embodiment of a tube target (1 a) which has reduced susceptibility to fracturing. As is schematically illustrated, the tube target (1 a) has a connector piece (6 a) which in part protrudes from the target body (2 a). The tube target (1 a) furthermore has a damping element (4 a) which in the embodiment illustrated is disposed axially adjacent to the connector piece, specifically on that side of the connector piece that faces away from the illustrated end of the tube target.

(25) The connection between the connector piece (6 a) and the damping element (4 a) in this case may be implemented by welding or friction welding, for example.

(26) FIG. 2-1 shows a second design embodiment of a tube target (1 b). If no reference is made to the contrary, the elements and features of the tube target (1 a) which have been described above with reference to FIG. 1 may also be applied to the tube target (1 b) illustrated in FIG. 2-1.

(27) In contrast to the first design embodiment according to FIG. 1, FIG. 2-1 shows a tube target (1 b) having a target body (2 b) and at least one connector piece (6 b) as well as a damping element (4 b) which in the radial direction between connector piece (6 b) and target body (2 b), that is to say when viewed from the axis A in a radially outward manner, is disposed adjacent to the at least one connector piece (6 b). The damping element (4 b) also in this embodiment is embodied such that the former is connected to each one face of the connector piece (6 b) (in this case an external face) and one face of the target body (2 b) (in this case an internal face).

(28) FIG. 2-2 differs from FIG. 2-1 in that the axially inboard end region of the damping element (4 b′) in this embodiment extends radially across at least a part-region of the connector piece (6 b).

(29) FIG. 3 shows a third design embodiment of a tube target (1 c). If no reference is made to the contrary, the elements and features of the tube targets (1 a-b) which have been described above with reference to FIGS. 1, 2-1, and 2-2 may also be applied to the tube target (1 c) illustrated in FIG. 3.

(30) The three-dimensional arrangement of the embodiment shown in FIG. 3 corresponds to that of the tube target (1 b) shown in FIG. 2-1. In contrast to the tube target (1 b) described with reference to FIG. 2-1 the tube target (1 c) however has a damping element (4 c) which when viewed in the tangential direction has a cross section which contains a plurality of circular cross sections.

(31) Such a cross section may be achieved, for example, in that the damping element (4 c) has the three-dimensional shape of a spring, or else is constructed from one or a plurality of annular elements having a circular cross section, respectively.

(32) Alternatively (and not shown in the figures), a damping element according to the invention, also when viewed in the tangential direction, may have a differently configured cross section, such as one or a plurality of oval cross sections, for example, or else a cross section containing one or more square or rectangular cross sections.

(33) FIG. 4 shows a tube target (1 d) having a target body (2 d) and a connector piece (6 d) which likewise has a damping element (4 d).

(34) In contrast to the embodiments of the invention illustrated in FIGS. 1 to 3, the damping element (4 d) is at least in part disposed on an inboard face of the connector piece (6 d) and disposed between the connector piece (6 d) and the target body (2 d) only in the inboard end region of the damping element (4 d). The effect of the damping element in this case is present in a targeted manner only in the inboard end region of the damping element.

(35) FIG. 4-2 differs from FIG. 4-1 in that the axially inboard end region of the damping element (4 d′) in this embodiment extends radially across at least a part-region of the connector piece (6 d).

(36) In preferred embodiments of the invention the at least on damping element (4 b-c) is disposed on an external face of the at least one connector piece (6 b-c).

LIST OF REFERENCE SIGNS

(37) 1 a-d Tube target 2 a-d Target body 4 a-d Damping element 6 a-d Connector piece A Axis of tube target