JP5075662B2 - Multi-target sputtering system - Google Patents

Description

  The present invention is a sputtering apparatus in which high-energy particles collide with a target in a vacuum chamber, thereby firing material molecules constituting the target from the target, and a plurality of targets arranged in the vacuum chamber are sequentially transferred to a sputtering position. And a multi-target sputtering apparatus that can perform sputtering.

  When a multilayer thin film is formed on a substrate such as a semiconductor wafer by sputtering, it is necessary to sequentially sputter targets made of different materials in a vacuum chamber to form a plurality of materials on the substrate. . Even when a single material layer is formed, if there are multiple substrates and a large amount of target is required, it is necessary to sputter another new target instead of the target consumed by sputtering. is there.

  Conventionally, when a plurality of targets are sputtered and formed on a substrate as described above, a necessary number of target sources including a target and a sputtering electrode for sputtering the target are previously installed in a vacuum chamber. It was necessary to keep. However, in order to install a plurality of target sources in the vacuum chamber in this way, as many sputtering power sources as the number of the sputtering sources are required, and the apparatus becomes large.

  Therefore, as a multi-target sputtering apparatus capable of efficiently performing a sputtering process by exchanging a plurality of targets efficiently in a short time in a vacuum chamber, for example, a device described in JP-A-2002-256425 is known. This multi-target sputtering apparatus is provided with a turntable-shaped target holder that rotates below the position where the target is sputtered in a vacuum chamber, and a plurality of targets are arranged on a circumference at a certain distance from the rotation center of the target holder. Then, by rotating the target holder and stopping its positioning, a plurality of targets are sequentially conveyed directly below the sputtering position, and the target is sputtered up to a position where the target is sputtered by a sputtering electrode that is lifted and lowered by a lifting mechanism. . And after sputtering a target, a sputtering electrode is lowered | hung with an raising / lowering mechanism, and a target is returned to a target holder. Next, the next target is conveyed directly below the sputtering position by intermittent rotation of the target holder, and similarly pushed up to the sputtering position and sputtered.

In recent years, the number of thin film layers formed on a substrate tends to increase, and for this reason, the number of targets used for the same substrate has increased. For this reason, the number of targets used during the film-forming process by sputtering is also increasing.
However, in the target replacement method as described above, when the number of targets increases, the diameter of the target holder must be increased accordingly. Since the target holder is provided in the vacuum chamber, an increase in the diameter increases the volume of the vacuum chamber. When the volume of the vacuum chamber increases, not only the entire apparatus becomes larger, but also peripheral devices such as a vacuum pump that vacuums a large volume vacuum chamber must be strengthened. It becomes difficult.

JP 2001-234336 A JP 2002-256425 A Japanese Patent Laid-Open No. 2004-6160 JP 2005-220369 A JP 2007-197749 A

  In view of the problems in the conventional multi-target sputtering apparatus, the present invention does not require an increase in the number of required targets or an increase in the diameter of the vacuum chamber, thereby reducing the overall size of the vacuum chamber. An object of the present invention is to provide a multi-target sputtering apparatus that can be realized.

  In the present invention, in order to achieve the above object, a plurality of targets 7 are arranged on a circle, and turntable-like target holders 3 that are intermittently rotated around the circle are arranged in multiple stages in a vacuum chamber. . This eliminates the need to increase the diameter of the vacuum chamber 1 even if the number of required targets 7 increases, and therefore, a plurality of thin films can be formed on the substrate using more targets in the vacuum chamber. I made it.

Such a multi-target sputtering apparatus sequentially transports a plurality of targets 7 to a sputtering position in the vacuum chamber 1, sequentially deposits the targets 7 at the sputtering position, and deposits a thin film on the substrate 12 facing the target 7. It is something to be made. In the present invention, a plurality of targets 7 are arranged side by side on a circle, and a target holder 3 having at least one empty holding hole 8 to which no target 7 is attached is vertically arranged in a vacuum chamber 1 in multiple stages. The target holder 3 is moved up and down through a rotating mechanism 5 that rotates the target holder 3 independently and intermittently around the center of the circle, and through an empty holding hole 8 of the target holder 3. The sputter electrode 2 is brought into contact with the lower surface of the target 7, and an elevating mechanism 4 for elevating the target 7 between the target holder 3 and the target position is provided.

The empty holding hole 8 in which the target 7 of the target holder 3 is not mounted is a holding hole 8 in which the target 7 can be mounted but the target 7 is not mounted .

  In such a multi-target sputtering apparatus according to the present invention, the target holders 3 in which a plurality of targets 7 are arranged on a circle having the same diameter are arranged in multiple stages up and down, and they are intermittently rotated around the rotation center thereof. Since the target 7 is moved up and down between the target holder 3 and the sputtering position by the elevating mechanism 4 and sequentially sputtered, more targets 7 can be arranged in the vacuum chamber 1 without increasing the diameter of the target holder 3. I can do it. Thereby, even if the number of targets 7 increases, it can be designed so that the diameter of the vacuum chamber 1 is not increased only by slightly increasing the height of the vacuum chamber 1. Therefore, even when many targets are used, it is not necessary to increase the volume of the vacuum chamber.

  As described above, in the multi-target sputtering apparatus according to the present invention, a larger number of targets 7 can be accommodated in the vacuum chamber 1, and these targets 7 can be sequentially sent to the target position and sputtered. As a result, when more layers of thin films are formed on the substrate 12, these layers can be formed while the substrate 12 is left in the vacuum chamber 1. In addition, since it is not necessary to increase the diameter of the vacuum chamber 1 in accordance with the number of targets 7, it is possible to collect as a compact device for the number of targets 7.

In the present invention, target holders 3 in which a plurality of targets 7 housed in the vacuum chamber 1 are arranged in a circle are arranged in multiple stages in the vertical direction, and these target holders 3 are intermittently rotated to feed the targets 7 in order. The target 7 was sent to the target position for sputtering.
Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.
FIG. 1 is a longitudinal sectional side view of a main part of a vacuum chamber 1 of a multi-target sputtering apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, a target holder 3 in which a plurality of targets 7 are arranged on a circle is arranged in two stages in the vertical direction inside the vacuum chamber 1. The target holder 3 is supported by a support shaft of a rotation mechanism 5 that introduces rotational movement from the outside under the vacuum chamber 1, and is intermittently rotated around the center of the circle on which the target 7 is disposed. More specifically, the rotation center 6 of the target holder 3 by the rotation mechanism 5 here coincides with the center of the circle on which the target 7 is arranged, and the interval of the intermittent rotation is on the circle on which the target 7 is arranged. The pitch is the same as the interval. The support shaft of the rotation mechanism 5 is individually provided coaxially with respect to each target holder 3, and the plurality of target holders 3 are intermittently rotated independently of each other. Target holder 3 An example of the target holder 3 will be described later.

  There is a sputtering position directly above the position where the target 7 of the target holder 3 stops. Directly below the sputtering position, the target 7 mounted on the target holder 3 sequentially stops as the target holder 3 rotates intermittently.

  A substrate holder 11 is disposed directly above the target position in the vacuum chamber 1, and the substrate 12 is held on the lower surface of the substrate holder 11. The substrate 12 held on the lower surface of the substrate holder 11 faces the target 7 in the vertical direction at a position where the target 7 held by the target holder 3 stops. The substrate holder 11 is moved up and down by an elevating mechanism 18 of a type that introduces vertical movement from outside the vacuum chamber 1.

On the other hand, a sputter electrode 2 that is in contact with the lower surface of the target 7 held by the target holder 3 and stopped just below the target position and applies a sputter voltage to the target 7 is disposed directly below the target position. . That is, the sputtering electrode 2 faces the substrate 12 on the lower surface of the substrate holder 11 with the target 7 stopped just below the target position.
The sputter electrode 2 has an electrode structure including, for example, a magnet for generating ions that collide with the target 7. A power source 9 for applying a high frequency voltage to the sputter electrode 2 is provided outside the vacuum chamber 1 and below the vacuum chamber 1.

  Further, the sputter electrode 2 is moved up and down by an elevating mechanism 4 of a type in which vertical movement is introduced from the outside under the vacuum chamber 1. The elevating mechanism 4 moves the sputter electrode 2 up and down to bring the sputter electrode 2 into contact with the lower surface of the target 7 held by the target holder 3, and further raises and lowers the target 7 to bring the target 7 to the target position. It is raised and returned to the target holder 3 again.

  FIG. 2 shows a plan view of the two-stage target holder 3. The upper and lower target holders 3 respectively shown in (A) and (B) have the same configuration. In the illustrated case, five holding holes 8 of the target holder 3 for mounting and holding the target 7 are provided at intervals of 72 ° on a circle around the rotation center 6 of the target holder 3. One of the holding holes 8 is empty, and the target 7 is mounted on the four holding holes. Note that there may be a plurality of empty holding holes 8 on which the target 7 is not mounted if the number of targets 7 to be sputtered is small.

Positioning marks 10 are also provided on the circumference of the target holder 3 at intervals of 72 °. These positioning marks 10 are used for positioning when the target holder 3 is intermittently rotated.
In the multi-target apparatus shown in FIGS. 1 and 2, the target holder 3 is provided in two stages in the upper and lower directions, but three or more stages can be provided.

Next, a series of operations of this multi-target sputtering apparatus will be described.
First, as shown in FIG. 1, a substrate 12 is mounted in advance on the lower end portion of the substrate holder 11 in the vacuum chamber 1. Also, the empty holding hole 8 of the lower target holder 3 is set at a position between the substrate 12 and the sputter electrode 2 facing each other. On the other hand, the upper target holder 3 stops the target 7 to be sputtered first at a position between the substrate 12 and the sputtering electrode 2 facing each other.

  From this state, the sputtering electrode 2 is raised by the lifting mechanism 4 through the empty holding hole 8 of the lower target holder 3, and the sputtering electrode 2 is brought into contact with the lower surface of the target 7. Further, the target 7 is placed on the sputtering electrode 2 and the target 7 is raised to the target position. Therefore, a sputtering voltage such as a high frequency voltage is applied to the sputtering electrode 2 to sputter the target 7, whereby molecules generated from the target 7 are deposited on the film forming surface of the substrate 12 facing upward. Thereafter, the sputtering electrode 2 is lowered by the elevating mechanism 4, the target 7 is returned to the target holder 3, and the sputtering electrode 2 returns to the original position.

  Thereafter, the upper target holder 3 rotates intermittently, and the target 7 to be sputtered next moves to a position between the substrate 12 and the sputtering electrode 2 facing each other. Here, in the same manner as the first target 7, the sputtering electrode 2 is raised by the elevating mechanism 4, the target 7 is placed thereon, and the target 7 is raised to the target position. Therefore, the target 7 is sputtered to form a film on the substrate 12. Thereafter, the target 7 is returned to the upper target holder 3, and the sputter electrode 2 returns to its original position. Thereafter, a plurality of targets 7 mounted on the upper target holder 3 are sequentially sputtered in the same manner, for example, four targets 7 in the illustrated embodiment.

  Next, the upper target holder 3 is intermittently rotated, and the empty holding hole 8 is moved to a position where the substrate 12 and the sputtering electrode 2 face each other. In this state, the lower target holder 3 rotates intermittently, and the next target 7 to be sputtered moves to a position between the substrate 12 and the sputter electrode 2 facing each other. Here, the sputtering electrode 2 is raised by the elevating mechanism 4 through the empty holding hole 8 of the upper target holder 3, and the target 7 is placed thereon to raise the target 7 to the target position. Therefore, the target 7 is sputtered to form a film on the substrate 12. Thereafter, the target 7 is returned to the lower target holder 3, and the sputter electrode 2 returns to its original position. Thereafter, a plurality of targets 7 mounted on the lower target holder 3 in the same manner, for example, four targets 7 in the illustrated embodiment, are sputtered.

  As described above, all the targets 7 mounted on the upper and lower two-stage target holders 3 are sputtered. When the target holder 3 is provided with three or more stages, the basic operation is exactly the same, and the number of times increases only as the number of stages of the target holder 3 increases. In the example of the operation described above, sputtering is performed from the target 7 mounted on the upper target holder 3, but the order is arbitrary.

  In the multi-target sputtering apparatus according to the present invention, a larger number of targets 7 are accommodated in the vacuum chamber 1 and can be sputtered by sequentially sending the targets 7 to the target position. Therefore, it can be used in the field of thin film formation, etc.

It is a principal part vertical side view of the part of the vacuum chamber of the multi-target sputtering device which is one Example of this invention. It is a top view which shows the example of the target holder used for the same multi-target sputtering device, and the target with which it was mounted | worn.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum chamber 7 Target 12 Substrate 3 Target holder 5 Rotating mechanism 4 Elevating mechanism 2 Sputter electrode 8 Empty holding hole

Claims (2)

A plurality of targets (7) are sequentially transferred to the sputtering position in the vacuum chamber (1), and the target (7) is sequentially sputtered at the sputtering position to form a thin film on the substrate (12) facing the target (7). In a multi-target sputtering apparatus to be deposited, a plurality of targets (7) are arranged side by side on a circle, and a target holder having at least one empty holding hole (8) in which no target (7) is mounted. 3) are provided in multiple stages in the vacuum chamber (1), and a rotation mechanism (5) for independently rotating the target holder (3) independently around the center of the circle, and a target holder (3) By raising and lowering the sputter electrode (2) through the empty holding hole (8), the target (7) of the target holder (3) Sputter electrode (2) is brought into contact with the surface, the multi-target sputtering apparatus, characterized in that it comprises a lifting mechanism (4) for raising and lowering between the target position the target (7) target holder (3). Empty holding hole that does not have a target (7) of the target holder (3) (8), according to claim 1, characterized in that the target (7) mountable retaining hole (8) Multi-target sputtering equipment.

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