JPH0234780A - Magnetic circuit for magnetron sputtering - Google Patents

Abstract

PURPOSE:To increase the efficiency of utilization of a target for sputtering and to improve the quality of a film by forming first and second magnetic circuits, alternating the polarities of magnets from the central magnet to the peripheral magnet and varying the distribution of magnetic flux density on the target. CONSTITUTION:The title magnetic circuit is composed of a first magnetic circuit 12 and a second magnetic circuit 16 and the polarities of magnets are alternated from the central magnet 19 to the peripheral magnet 10. The first circuit 12 is formed with the central magnet 19 and the peripheral magnet 10 different from the magnet 19 in polarity set around the magnet 19. The second circuit 16 is formed between the magnets 19, 10 with a pair of magnets 13, 14 similar in shape to the magnet 10 and having different polarities.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the configuration of a magnetic circuit used in a magnetron sputtering apparatus.

BACKGROUND OF THE INVENTION A schematic diagram of a cathode portion of a conventional magnetron sputtering apparatus is shown in FIG. FIG. 5(a) is a configuration diagram of the cathode portion, in which a magnetic circuit 2 for magnetron sputtering, a sputter target 4 bonded to a backing plate 3, and a cooling system 5 are attached to the cathode holder 1. As shown in FIG. 5(b), the magnetron sputtering magnetic circuit 2 has a center magnet 6 and peripheral magnets 7 of different polarities attached to a yoke 8, forming a closed magnetic circuit. In the example of FIG. 5, the center magnet 6 is N1
Although the peripheral magnet 7 is S, there is also an example of the opposite.

Problems to be Solved by the Invention In the above-mentioned prior art, the magnetic flux density in the magnetic circuit shown in FIG. figure(
The broken part in a) becomes as shown by the line. When such a distribution is shown, the shape of the plasma generated on the sputter target 4 is as shown in the upper diagram of FIG.
As shown by the broken line in C), the depth differs locally. When two lotions are generated locally in this way, (1) only a part of the sputter target 4 can be used, resulting in poor usage efficiency; (2) sputter particles are scattered only from a part of the sputter target 4, which reduces the productivity of the sputter target 4; In addition to the occurrence of film thickness distribution in the formed thin film, problems arise in that there are parts with poor step coverage.

The magnetic circumference for magnetron sputtering of the present invention solves the above-mentioned problems, and aims to improve the utilization efficiency of the sputter target and the film quality of the thin film produced and deposited.

Means to solve problems The magnetic circuit for magnetron sputtering of the present invention is N.

S A first magnetic circuit including a center magnet having one polarity or gender, peripheral magnets having a polarity different from the center magnet around the center magnet, and a magnetic circuit between the center magnet and the peripheral magnets of the first magnetic circuit. At the periphery, a 21st magnetic circuit consisting of a pair of two magnets, N and S, each having a similar shape to the magnet, is provided, and the polarity of the magnets from the center magnet to the peripheral magnet of the first magnetic circuit is set to N, S or N. S and N are arranged alternately. Further, the first magnetic circuit and the second magnetic circuit are independent, and are provided with a side whose relative position can be changed. Furthermore, the output signal from a Gauss meter installed near the sputter target operates the elevator of the second magnetic circuit and an actuator installed on the side, thereby changing the relative positions of the first magnetic circuit and the second magnetic circuit. .

Effects According to the above configuration, the magnetic flux density distribution generated on the sputter target can be changed and plasma can be generated uniformly over a large area, thereby improving the utilization efficiency of the sputter target and reducing the thickness of the thin film formed. Uniformity and step coverage can be improved.

Example Hereinafter, one embodiment of the present invention will be described based on the drawings.

1(a)(b) and FIG. 2(a)(b) are schematic configuration diagrams of the magnetic circuit for magnetron sputtering of the present invention, and FIG. 1 is for a circular sputtering target,
FIG. 2 is for a rectangular sputter target. FIG. 3 is a schematic diagram of a cathode section in which a magnetic circuit for magnetron sputtering according to the present invention is installed. Further, FIG. 4 is a diagram comparing the magnetic flux density distribution, plasma shape, and erosion depth when using the magnetic circuit and path for magnetron sputtering of the present invention with those using a conventional magnetic circuit.

As shown in FIGS. 1 and 2, the magnetic circuit for magnetron sputtering of the present invention has a first magnetic circuit 12 in which a center magnet 9 with an N pole and a peripheral magnet 10 with an S pole are arranged on a yoke 11.
The second magnetic circuit 16 is disposed between the center magnet 9 and the peripheral magnet 10 of the first magnetic circuit 12 and has a similar shape to the peripheral magnet 10. second magnetic circuit, path 16 is N;
It consists of two center side magnets 13, a peripheral side magnet 14, and a yoke 15, with S as a pair.The center side magnet 13,
The polarity of the peripheral magnet 14 is the same as that of the N-pole central magnet 9 of the first magnetic circuit 12. The relationship between the area around the S pole and the magnet 10 (from the relationship,
The center magnet 13 is the S pole and the peripheral magnet 14 is the N pole so that N and S are alternated. In addition, the first and second
The polarity and polarity of each magnet in the magnetic circuit 12, 16 may be reversed from the above example. Next, a lifting mechanism 17 is attached to the second magnetic circuit/path 16 so that its relative position with the first magnetic circuit/path can be changed.

A cathode portion provided with a magnetic circuit for magnetron sputtering according to the present invention will be explained with reference to FIG.

A cathode holder 1 is equipped with a magnetic circuit, a sputter target 4 bonded to a backing plate 3, and a cooling system 5, and an insulator 1 is placed in a vacuum chamber 18.
It is installed via 9.

The cathode holder 1 has a lifting mechanism 17 for the second magnetic circuit 16.
An actuator 20 is installed to move the. Also,
A Gauss meter 21 is installed in the vacuum chamber 1 together with a movable mechanism 22 to measure the magnetic flux density on the sputter target 4.
It is installed at 8.

The actuator 20 is operated by the output signal from the Gauss meter 21, and adjusts the height of the second magnetic circuit 16 so that the distribution of magnetic flux density on the sputter target 4 is optimal. Note that when plasma is generated on the sputter target 4 to form a film, the Gauss meter 21 is moved from above the sputter target 4 by the movable 8 mechanism 22 so that the Gauss meter 21 is not formed into a film.

The effect of the above configuration will be described below using FIG. 4. By adjusting the height of the second magnetic circuit 16, the relative position with respect to the first magnetic circuit 12 is changed,
The distribution of the magnetic flux density on the sputter target 4 in the direction perpendicular to the target surface is as shown in FIG. 4(a). That is, it is set so that there are three points where the magnetic flux density in the vertical direction is zero. The magnetic flux density in the vertical direction is O
It is known that the plasma density reaches its maximum at the point where
As shown in the figure below, plasma is generated over a wide area, and as a result, the sputter target 4
As shown in FIG. 4(C), a large area of the target can be used for the erosion that occurs. Furthermore, since the magnetic flux density distribution can be easily adjusted when two lotions develop on the target and the permeation-magnetic flux density changes, or when using sputtering targets 4 with different magnetic permeabilities, the film forming conditions are always can be maintained at its best. Therefore, (1) Target utilization efficiency increases. (
2) Since the film is formed by scattering sputtered particles from a wide area, a thin film with a small film thickness distribution and good step coverage can be created. (3) Films can be formed under the best conditions even when the target is exhausted or when a target of a different material is used.

Effects of the Invention The magnetic circuit for magnetron sputtering of the present invention dramatically increases the utilization efficiency of the target and improves the quality of the thin film formed, thereby realizing lower product costs while maintaining a high yield. .

Furthermore, even when targets made of different materials are attached, the film forming conditions can be easily set, which increases the operating time of the film forming apparatus and allows for effective use of the apparatus.

[Brief explanation of the drawing]

FIG. 1 is a wII schematic configuration diagram of a magnetic circuit for magnetron sputtering according to an embodiment of the present invention, and FIG. 2 is a schematic diagram of a magnetic circuit for magnetron sputtering according to a different embodiment of the present invention.
Fig. 3 is an outline and schematic configuration diagram of the cathode section in which the magnetic circuit for magnetron sputtering of the present invention is installed, and Fig. 4 shows the magnetic flux density distribution, plasma shape, and FIG. 5 is a diagram comparing the lotion depth with that of a conventional magnetic circuit. FIG. 5 is a schematic diagram of a conventional magnetic circuit for magnetron sputtering and a cathode section in which it is installed. 9... Center magnet, 10... Peripheral magnet, 11... Yoke, 12... First magnetic circuit/path, 13... Center side magnet, 1
4. Peripheral magnet, 15. Yoke, 16. 21st
ift air circuit, 17. Lifting mechanism, 18. Vacuum chamber, 19. Insulator, 20. Actuator, 21.
・Gauss meter 22...Movable 1a1 structure. Name of agent: Patent attorney Shigetaka Awano (Q) Vertical 1st phase (b)

Claims (3)

[Claims] (1) A first magnetic circuit including a center magnet and a peripheral magnet having a polarity different from that of the center magnet arranged around the center magnet, and a first magnetic circuit having a peripheral magnet having a similar shape to the peripheral magnet between the center magnet and the peripheral magnet. A magnetic circuit for magnetron sputtering, wherein a second magnetic circuit is provided with a pair of two magnets, N and S, and the polarities of the magnets from the center magnet to the peripheral magnets are alternated. (2) The magnetron sputtering according to claim 1, wherein the first magnetic circuit and the second magnetic circuit are made independent, and an elevating mechanism is provided that can change the relative position of the second magnetic circuit with respect to the first magnetic circuit by elevating and lowering the second magnetic circuit. magnetic circuit. (3) The relative position of the first magnetic circuit and the second magnetic circuit is changed by operating an actuator that moves an elevating mechanism provided in the second magnetic circuit using an output signal from a Gauss meter provided near the sputter target. Or the magnetic circuit for magnetron sputtering according to 2.