JPS61124567A - Sputtering device - Google Patents

Abstract

PURPOSE:To make the consumption of a target uniform, to improve the effective use rate, and to form a thin film by a target material at a high speed by providing two pairs of magnets on the lower part and the side part of the target, in a sputtering device using a magnetron. CONSTITUTION:In a magnetron type sputtering device, magnets 13, 14 are placed on the lower part of a magnetic material target 11, and also magnets 15, 16 are placed on the side upper part as well. The target 11 is filled with a magnetic field flux 17 by the magnets 13, 14, and a parallel magnetic field flux 18 is formed on the surface of the target 11 by the magnets 15, 16. Accordingly, an electron from a filament executes a cyclotron motion by a strong magnetic field being parallel to the target, the ionization of a particle of the target material is quickened, and a thin film of the target material can be formed on a substrate at a high speed. Also, the target 11 is consumed on an average extending over the whole surface, a thin target can be used as well, and its service life can be extended.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a sputtering apparatus using a magnetron, particularly for coating magnetic materials at high speed and uniformly.

Conventional configurations and their problems Generally, sputtering is a method in which a gas discharge is generated in a low vacuum atmosphere, the generated ions impact the cathode, and the particles ejected from the target are coated on the substrate, making it difficult to control the composition and operate the equipment. It is widely used for film deposition because it is easy to apply, but compared to vacuum evaporation and vapor phase plating,
The drawback is that the film formation rate is slow.

Therefore, efforts have been made to increase the film formation rate of sputtering, and planar magnetrons called high-speed sputtering have been used.

As shown in FIG. 1, its specific configuration includes a vacuum chamber 1, a vacuum pump 2 for evacuating the vacuum chamber, a cathode 3 installed in the vacuum chamber 1 to which a high voltage can be applied, and a cathode 3 facing the cathode 3. The substrate 3a is arranged in such a manner that the cathode 3 and the substrate 3a are
Water-cooled target 7 like a shirt placed between
, a magnetic field generator 8 such as a permanent magnet or an electromagnet arranged in a pair in a direction perpendicular to the direction of the cathode 3 and the substrate 3a at the bottom thereof, and a ground 9 provided near the target. A leak valve 6 for introducing gas is provided.

First, set the substrate 3& in the vacuum chamber 1, and
evacuate the inside of the vacuum chamber 1, and close the leak valve 6 as necessary.
Introduce more human gas, etc., and maintain an appropriate degree of vacuum (generally 10~
10 Torr) and collide with force to knock out the target material and deposit the target material on the substrate. At that time, the magnet at the bottom of the cathode creates a magnetic field on the surface of the target 3, causing electron cyclotron movement, promoting ionization of gas on the target 3 surface, increasing the number of collisions between ions and the target, and sputtering. The need to form large quantities of magnetic material films such as Rizocolla film in mass production with zero space is becoming stronger day by day, but in the case of sputtering these magnetic materials, the magnetic field flux is In order to leak onto the target m surface,
As shown in Figure 3 (&), even if a strong magnet is used, the
is the limit, and if the thickness is larger than that, the target will only be magnetized as shown in Figure 3(b), and the magnetic field flux will not be strong enough to reach the target surface, so magnetron movement will not occur and magnetron sputtering will not work. There is a problem that the advantage of high-speed film formation is lost.

As a solution to this problem, for example, as shown in Figure 4, there is a method of cutting a groove in the target (sold by Japan Vacuum Technology Co., Ltd. as GT Metal), or a method of placing a magnet on the upper part of the target side as shown in Figure 5. method (Japanese Patent Application Laid-Open No. 58-1302.
Publication No. 77) etc. have been clarified. however,
The structure shown in Fig. 4 naturally has the drawbacks that the processing is complicated, the cost increases, and the reduction of the target is uneven as shown in Fig. 6, and there are few materials that are effective for sputtering. In addition, when the magnet is placed on the upper part of the target side as shown in Fig. 6, the non-magnetic material target Q has a magnetic field flux passing through the target surface like the above-mentioned Brainer Magnetro/, but with the magnetic material target, The magnetic field flux is greatly bent by the magnetic material, and most of it passes through the magnetic material target and does not come out on the target surface, and the effect is extremely reduced, resulting in a film formation rate that is far from the high-speed sputtering that was originally intended. It had the disadvantage of not having

Purpose of the Invention In view of the above-mentioned drawbacks, the present invention provides a sputtering apparatus that uses an inexpensive target even for magnetic materials, effectively uses the target material, and, as a result, can form a film with a uniform thickness at high speed. It is something to do.

Structure of the Invention The present invention comprises a vacuum chamber, a vacuum pump for evacuating the vacuum chamber, a cathode installed in the vacuum chamber to which a high voltage can be applied, a substrate facing the cathode, and a space between the cathode and the substrate. The cathode consists of a water-cooled target, at least two magnets disposed below the target, and a steel upper part of the target. The sputtering device consists of at least two magnets arranged in the same direction, and each magnet is arranged so that the magnetic field flux does not flow substantially perpendicularly to the target. This has the effect of facilitating sputtering film formation.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

Magnets 13 and 14 are placed below the magnetic material target 11, and the target 11 is filled with flux 17 by the pair of magnets. This magnet and flux may be of the same level as in conventional planar magnetrons, and if the target is not a magnetic material, the target surface will have a flux of 200 to 50
It is desirable that a magnetic field of 0 Gauss be generated. Next, magnets 15 and 16 are placed on the steel upper part of the target, and a flux 18 of 10 to 500 Gauss parallel to the target is generated on the surface of the target 11 by the pair of magnets.

In other words, the magnetic field slack of the magnetic material target is filled or almost filled by the magnet at the bottom, so
Unlike in the past, the magnetic field on the upper part of the steel is not attracted to and absorbed by the magnetic target, and a strong magnetic field flux is generated near the target surface.

Therefore, electrons undergo cyclotron motion due to the strong magnetic field parallel to the target, promoting ionization and enabling high-speed film formation. At the same time, the magnetic field flux entering the target perpendicularly from above is extremely small, and the magnetic flux parallel to the target on the target surface is Because it is almost uniform, there is no problem that part of the target is dug up and the effective amount of target is small, and the target thickness is 3"
It has the effect that it can be used not only at a thinness of only 10 g, but also at a thickness of about 10%, and the target life is extended, making it possible to form long films and thick films on an industrial production basis.

Further, in the present invention, even when a magnetic target is not used, a magnetic field flux parallel to the target can be obtained, so high-speed bottom film formation is possible, but the magnetic field is strong at the target surface. Therefore, it is desirable to remove the upper steel magnet or move the lower magnet away from the target to obtain a suitable target surface magnetic field.

The specific arrangement of the above magnets is as follows: The lower magnet is a rare earth magnet placed 2% below the target, with the magnetic poles facing each other, placed perpendicularly at the opposing ends.
The upper magnet on the target side was placed horizontally just above the magnet on the lower part of the target with the same polarity as the lower magnet, but they may be placed vertically or horizontally, or two or more may be placed.

However, in the case of two or more magnets, instead of alternating opposite magnetic poles, they should generally be made into a collection of like poles to form a pair of magnets, and the steel upper and lower parts should also be similar. Even if they are not directly above each other, they should be placed so that they are generally on the same pole. Furthermore, if the upper and lower magnets are rotated synchronously, the 8th
As shown in the figure, the target is reduced more uniformly, and the uniformity of the deposited film thickness is further improved. Further, it goes without saying that the magnet may be a permanent magnet or an electromagnet.

Effects of the Invention As described above, in the present invention, the cathode is composed of a water-cooled target, at least two magnets arranged at the lower part of the target, and at least two magnets arranged at the steel upper part of the target, By arranging each magnet so that the flux of the magnetic field does not flow substantially perpendicularly to the target, it is possible to easily form a film by sputtering at high speed and uniformly even with a magnetic target. The effect is like a dog.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the sputtering equipment, Figure 2 is the cause of the cross-sectional pattern of a conventional planar magnetron cathode, and Figure 3 (
a) is a cross-sectional schematic diagram of a planar magnetron cathode when the magnetic material target is 3% or less, FIG. 3(b) is a cross-sectional schematic diagram of a planar magnetron cathode when the magnetic material target is used, and FIG. FIG. 5 is a schematic cross-sectional view of a cathode in another conventional example of magnetron sputtering, FIG. 6 is a cross-sectional view showing a conventional method of target reduction, and FIG. 7 is a cross-sectional view of an embodiment of the present invention. FIG. 8 is a schematic cross-sectional view of the cathode, and is a cross-sectional view showing how the target is reduced according to the present invention. 1... Vacuum chamber, 2... Vacuum pump, 3
...Cathode, 4...Shutter, 6.
...Power supply, 6...Leak valve, 7...
...Target, 8...Magnet, 9...
・Earth, 10...- Magnetic field flux, 11...
...Magnetic material target, 12...Power supply, 1
3.14...Target lower magnet, 15.16
・・・・・・Target side upper magnet. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure a Figure 2 9 Figure 3 1θ Figure 4 1θ

Claims (7)

[Claims] (1) A vacuum chamber, a vacuum pump that evacuates this vacuum chamber,
A cathode installed in the vacuum chamber to which a high voltage can be applied, a substrate facing the cathode, a shutter placed between the cathode and the substrate, a power source to apply a high voltage to the cathode, and a The cathode is equipped with a leak valve that can introduce gas, and the cathode is equipped with a water-cooled target,
A sputtering apparatus comprising at least two magnets arranged below the target and at least two magnets arranged above the side of the target. (2) The sputtering apparatus according to claim 1, wherein the magnetic field fluxes of the magnets at the lower part of the target and the magnets at the upper part of the target side do not flow substantially perpendicularly to the target. (3) The sputtering apparatus according to claim 1, wherein the magnet at the lower part of the target and the magnet at the upper part of the target side are arranged with their magnetic pole directions aligned so that they form a pair of opposing magnetic poles. (4) The magnet at the bottom of the target and the magnet at the top of the target side are arranged so that the magnet at the top of the target side is almost above the magnet at the bottom of the target, and their magnetic poles are the same. The sputtering apparatus according to item 1. (5) Claim 1 in which the target uses a magnetic material
The sputtering apparatus described in . (6) The sputtering apparatus according to claim 5, wherein the magnet at the bottom of the target substantially fills the magnetic material target with magnetic flux, and the magnet at the top of the target side generates a magnetic flux parallel to the target surface on the target surface. . (7) The magnetic field parallel to the target surface on the target surface is 1
7. The sputtering apparatus according to claim 6, wherein the sputtering temperature is 00 to 500 Gauss.