JPH0688229A - Electric control for rotation of magnetic zone of spattering target in double cylindrical magnetron - Google Patents

Abstract

PURPOSE: To facilitate positional control of a sputtering zone demarcation magnet in a target by freely rotating a cooling pipe fixed to the magnet arranged in a cylindrical target and rotating in response to an external motor source.

CONSTITUTION: Magnets arranged in cylindrical targets 27, 29 in a vacuum chamber 11 in response to external motor sources 49, 55 are supported rotatably. The magnets are arranged along the longitudinal direction of the targets 27, 29 and are fixed to cooling pipes 43, 45. This fixing is realized by setting the cooling pipe 43, 45 rotatable. Further, for rotating the magnets, the cooling pipes 43, 45 extending longer than the targets 27, 29 to the outside are connected to the motor sources 49, 55 and are controlled by a center sputtering system 59. Thus, the positions of the sputtering demarcation magnets in the targets 27, 29 are controlled.

COPYRIGHT: (C)1994,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron of a type using a rotating cylindrical sputtering target, and more particularly to a technique for controlling a magnetic field by a magnet in such a sputtering target.

[0002]

Cylindrical magnetrons have begun to be widely used for film deposition on substrates. An example is the deposition of a stack of insulation and metal on the surface of a glass substrate for the purpose of filtering out some of the solar energy and preventing it from passing through the glass. Such a substrate is placed in a vacuum chamber having at least one, and usually two, rotating cylindrical targets containing a sputtering material on the outer surface. Usually, both the inert gas and the reaction gas are enclosed in the vacuum chamber. Plasma is generated by the supply voltage of the sputtering target with the vacuum chamber closed box or the separated anode as a reference, and the plasma is limited to a portion along the sputtering zone of the target by a fixed magnet provided in the target. When the target is irradiated with plasma electrons and ions and the target passes through the fixed sputtering zone, the material is sputtered from the surface of the target and deposited on the substrate.

The magnets are usually permanent magnets, which are aligned in a rotating cylindrical target and are fixed with respect to the rotation of the target. The sputtering zone is formed by magnets located substantially along the entire length of the cylindrical sputtering target, and extends with a narrow portion (arc) of the circumference of the target. Typically, the magnet will have the sputtering zone located at the bottom of the cylindrical target and facing directly below it the substrate to be coated.

[0004]

It has recently been appreciated that for various reasons it is desirable to be able to move the sputtering zone some distance in the circumferential direction from the bottom position along the sputtering surface. Came to be. Such repositioning of the sputtering zone controls the angle at which the material is ejected from the target by sputtering. An example of one use of a dual cylindrical magnetron system using such an adjustment mechanism is 1990.
It is described in co-pending patent application, application number 549,392, filed July 6, 2012. The position of the sputtering zone is moved by rotating the permanent magnet within a certain angle range around the rotation axis of the target in which the permanent magnet is fixed. These rotational movements have been performed either by removing the cylindrical target structure or manually, both of which are tedious and time consuming.

It is a primary object of the present invention to provide improved mechanisms and techniques for controlling the position of sputtering zone defining magnets within a cylindrical target.

[0006]

The above and other objects are achieved by the present invention. According to the invention, briefly, generally speaking, a line of magnets arranged in a cylindrical target and oriented along its length is responsive to an external motor source, for example an electric step motor,
It is rotatably supported in the target so as to be movable in the circumferential direction. In order to achieve such magnet rotation, the fixing to the cooling tube in the target can be realized by making the cooling tube rotatable. A motor for rotating the permanent magnets is operatively connected to rotate the cooling tube, for which purpose the cooling tube extends sufficiently far beyond the rotating target. The motor source is controlled by a central sputtering system, allowing easy and automatic magnet repositioning whenever needed.

Other objects, features and advantages of the present invention will become apparent from the preferred embodiments and the accompanying drawings.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Prior to a detailed description of the preferred embodiment of the present invention,
The entire magnetron system using the present invention will be comprehensively described with reference to FIG. Box 11 indicated by a dotted frame
Is the metal wall of the vacuum chamber in which sputtering is performed. Inside that chamber are arranged two rotating sputtering cylindrical target structures 13 and 15 which are fixed on a frame 11 so as to be rotatable about their longitudinal axes. The target structures 13 and 15 are usually fixed so that their axes are parallel to each other, but this is not a necessary condition. Further, while FIG. 1 shows a dual target structure, many applications require only one target and other applications where the benefits of using more than two targets can be obtained. There is also. In most applications two structures 13 and 1
It is common to use 5.

FIG. 1 shows that the magnetron has a substrate 17 carried by a support structure 19.
The support structure 19 may be a roller so that the substrate 17 continuously passes through the vacuum chamber. The vacuum chamber is evacuated using a suitable pump system 21. One or more gases are supplied to the vacuum chamber by the gas source 23 by a suitable supply system such as a perforated tube 25 located across the vacuum chamber. The gas used depends primarily on the film that needs to be deposited on the substrate 17.

The cylindrical parts 27 and 29 of sputtering material, which are respectively arranged as parts of the target structures 13 and 15, may generally be the same material, but depending on the nature of the film deposited on the substrate 17. Different materials may be used. An electric motor source 31 arranged outside the vacuum chamber comprises a pulley 35 fixed to a toothed belt 33 and spindles 39 and 41, respectively.
And 37 are rotated to drive the target assembly. Sputtering materials 27 and 29 are fixed to spindles 39 and 41, respectively, for rotation therewith.

From the power source 40, a negative voltage is supplied to the sputtering surface with reference to the vacuum chamber metal frame 11 or another anode, which is usually connected to the ground potential, to form plasma in the vacuum chamber. . A plasma is formed adjacent to the sputtering zones of cylindrical sputtering targets 27 and 29 controlled by the placement of corresponding magnets (not shown in FIG. 1). These magnets have their corresponding sputtering targets 2
It is arranged along the length of 7 and 29 and has a small circumferential distance, ie a small arc distance. These magnets are fixed to the corresponding cooling tubes 43 and 45 and are most conveniently arranged in the sputtering targets 27 and 29. These cooling tubes form part of the respective target assembly so that they rotate independently of the rotation of the corresponding cylindrical sputtering targets 27 and 29.

In this way, the position of the magnets in each target assembly, and hence the position of the sputtering zone in each target assembly, is controlled by the rotation of these cooling tubes. Specifically, the pulley 47 is the tube 4
3 is fixed and is driven by an electric motor source 49 located outside the vacuum chamber through a toothed belt 51. Similarly, the pulley 53 is fixed to the cooling pipe 45, and through the toothed belt 57, the electric motor source 55 located outside the vacuum chamber is provided.
Is controlled and driven to a rotatable position. Motor source 49
Step types 55 and 55 are preferred and the corresponding tube 4
3 and 45 are held in selected positions and are held against rotation with the corresponding sputtering targets 27 and 29.

A coolant supply and disposal system (not shown) located outside the vacuum chamber, as indicated by arrow 61,
The cooling liquid is supplied to the cores of the tubes 43 and 45, and the arrow 63
As shown in (3), the cooling liquid whose temperature has risen is discharged from the space between the outer wall of the pipe and the inner wall of the spindle. The electric / electronic system 59 includes a power source 40 and motors 31, 49.
And controlling various parameters of the magnetron system shown, including 55.

A cross-sectional view of a preferred target assembly for the system of FIG. 1 is shown in FIG. A vertical cross-section along its length is shown. A cylindrical sputtering material target 71 has a spindle 73 at one end.
And to the spindle 75 at the other end. While the support block 77 omits details of known mechanical parts, it is shown in a simplified manner to focus on the important components. The block 77 supplies rotary movement, power and cooling fluid in addition to mechanical fixing action.

Inside the sputtering target 71 is a cooling pipe 79 for passing a cooling liquid. It is eccentrically fixed to provide space for the magnet 81 and its support structure 83 within the target 71. The permanent magnets are arranged in a straight line along substantially the entire length of the sputtering target 71. A view of these magnets as seen from the bottom of FIG. 2 is shown in FIG. Figure 4 shows the best,
The magnet extends along the cylindrical target 71 with a constant circumference (radiation angle). Auxiliary magnets 85 and 87 are arranged on opposite sides of the central magnet 81. The magnets are arranged with alternating poles. Therefore, these magnets are arranged along substantially the entire length of the target 71.
Form a narrow perimeter sputtering zone.

The sputtering zone is moved around the perimeter of the target 71 by rotating the magnet assembly about the axis 89 of the target assembly. The eccentric tube portion 79 is attached at its one end by means of a shaft sleeve or roller bearing 93 to a member 91 rotatable about a shaft 89 with respect to the spindle 75. At the opposite end, the projection 95 of the cooling tube 79 is mounted for rotation about the target assembly axis 89. The tube 95 extends beyond the spindle 73 and is supported by a fixed block 77 for easy rotation, for example by ball bearings 97. The spindle 73 is, for example, a ball bearing 99.
Is rotatably supported by the fixed block 77. In FIG. 2, details of the bearings and multiple seals have been omitted for convenience.

The cylindrical sputtering target 71 is normally rotated at a uniform speed by the chain gear 101 attached to the spindle 73. Through the toothed belt 103, the chain gear 101 is driven by an external motor source represented by the motor 31 in FIG. Similarly, the cooling tube 95, and thus the magnet assembly in the target 71, also
It rotates independently by the chain gear 105 fixed to.
The tooth belt 107 is the step motor 4 shown in FIG.
It is connected to an external motor source corresponding to 9 or 55. The use of a stepper motor to rotate the magnet structure has the advantage that a large number of different rotational positions can be set in the 360 ° range in which the motor can be stopped.

Electrical energy is supplied to the target 71 by a brush 109 which contacts the spindle 73 and is connected to a voltage source. Cooling liquid is the supply pipe 1
09 and the plastic member 111, and is supplied to the inside of the pipe 95. Water that circulates through the target assembly and reaches the chamber 113 in block 77 is pipe 115.
It is drained via.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a dual cylindrical sputtering target magnetron according to the present invention.

FIG. 2 is a cross-sectional view of a cylindrical target, its support mechanism and drive mechanism.

3 is a view of the magnet in the target of FIG. 2 seen from below, and is a cross-sectional view taken along line 3-3 of FIG.

4 is a cross-sectional view of the cylindrical target of FIG. 2, taken along line 4-4.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Milan Roman Cars California, USA 94549 Lafayette Gloria Terras 3291

Claims (10)

[Claims] 1. At least one sputtered material comprising a cooling tube fitted with a magnet such that the magnetic field zone is formed along a predetermined length of the cylindrical target and in a narrow portion of its circumference. A magnetron having a vacuum chamber with a cylindrical target, wherein said target rotates about one longitudinal axis with respect to said vacuum chamber and said magnet, said target being further disposed outside the vacuum chamber for rotation. In the magnetron operatively connected to a motor, the cooling tube is supported to allow the cooling tube to rotate completely with respect to the vacuum chamber and independently of the target, whereby the magnetic field zone is When the means for moving along the circumference of the target and the target motor are placed outside the vacuum chamber, Means operatively connected to the cooling pipe for rotating the cooling pipe and allowing the cooling pipe to rest at any of a plurality of rotational positions with respect to the vacuum chamber; and Control means arranged outside the vacuum chamber and connected to the motor source for controlling the operation of the motor source, the control means controlling the circumferential position of the magnetic field zone. A magnetron that is characterized. 2. The magnetron of claim 1 wherein said motor source includes a stepper motor having a plurality of different stable rotational positions that are stationary in response to an electrical signal from said control means. 3. The control means inputs a control signal to the step motor to move the step motor to a new position and a new position of the step motor at one of the plurality of rotational positions. The magnetron according to claim 2, wherein a speed of the rotating operation is designated. 4. The magnetron according to claim 1, wherein the plurality of rotational positions of the cooling pipe rotating means are spread in a range of substantially 360 degrees. 5. A magnetron for coating a film on a substrate in a vacuum chamber, comprising: at least two elongated target structures having cylindrical sputtering surfaces with central axes that are substantially parallel to one another. The at least two elongated target structures each having means for forming a magnetic field zone within the cylindrical sputtering surface and extending in a narrow portion of a circumference along the length of the sputtering surface. A means coupled to the target structure for rotating the sputtering surface about each axis at a substantially uniform velocity, and a magnet means for each of the at least two elongated target structures, Rotate the magnetic field zone around the set arc on the set arc. Electrical means for holding a magnetic field zone at a target fixed position within the arc, wherein the magnetic field zones are rotatable independently of each other and independently of the target structure. And a means for controlling rotation and position of the magnetic field zone, the magnetron being connected to an electric rotation means of the magnetic field zone. 6. The magnetron according to claim 5, wherein an arc range of the rotating means of the magnetic field zone is substantially 360 degrees. 7. The magnetic rotation means of the magnetic field zone has a plurality of different stable rotational positions at which the magnetic field zone rests in response to an electric signal from the control means. Magnetron. 8. The magnetic field for the control means to specify a position to be newly taken by the rotation means at one of the plurality of rotation positions and a speed of an operation for moving to the new position. 8. The magnetron according to claim 7, wherein a control signal is input to the electric rotating means of the zone. 9. The magnetron according to claim 5, wherein the electric rotating means of the magnetic field zone is an electric step motor. 10. The magnetron of claim 5, wherein the at least two sputtering surfaces have different material compositions.