JPS59208815A - Buried composite target in magnetron sputtering apparatus - Google Patents

Abstract

PURPOSE:To provide a large-sized sputtering target capable of forming accurately at a high speed with an amorphous vertically magnetized membrane of the prescribed composition. CONSTITUTION:A sputtering target 10 is formed of a base phase 11 made of rare earth metals such as gadolinium, terbium, dysprosium, holmium, and a buried phase 12 made of transition metal such as cobalt, iron. The base phase 11 is planely contacted with the cathode of a magnetron sputtering device, and the phase 12 is disposed at the free surface side opposite to the cathode. According to the sputtering target of such structure, the target can be manufactured merely by engaging a burying phase made of the transition metal in the base phase made of the rare earth metal. The metals of respective phases have no brittleness and good workability. Accordingly, an extremely large size can be readily manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sputtering device used in a sputtering apparatus for manufacturing an amorphous perpendicular magnetization film used as a magneto-optical recording medium or a magnetic pulp recording medium.
More specifically, the present invention relates to an improvement of the Snowcutter 1 non-climate used in a Yagnetron sputtering apparatus that enables high-speed, low-temperature film formation by applying a leakage magnetic field.

Recently, amorphous perpendicular magnetization in the straight direction has been developed using light using the magneto-optical effect. (This amorphous perpendicularly magnetized film is now being widely used, and is produced using a magnetron tuttering device.
As shown in FIG. 1, the Tron sputtering apparatus consists of a positive chamber 2 with a substrate 5 adsorbed on its lower surface and a non-containing chamber 2 on its upper surface in an argon atmosphere and low vacuum. A structure in which a target 6, which is abrasion of a crystalline perpendicularly magnetized film, and a cathode 3, which has a permanent magnet 4 sorbed to its lower surface that generates a strong magnetic flux, are placed so that the substrate 5, target 6, and 75 beads face each other. A high voltage is applied between the field pole 2 and the cathode 3 to generate a plasma discharge in the container 11) and to increase the plasma density near the magnet 6 by leaking the permanent magnet 4 ( A magnetic field is used to make the alcone ion generated by the plasma discharge collide efficiently with the surface of the target 6, and the target repelled by the collision is attached to the surface of the substrate 5, thereby making the surface of the substrate 5 non-uniform. A crystalline perpendicular magnetization film 7 is formed.

Conventionally, targets used in this magnetron sputter link device include alloy targets made by melting general KM transfer metals and rare earth metals in an arc furnace, etc., and sintering transition metals and rare earth metals made into fine powder. A sintered target, a chip-on target in which rare earth metal pieces are placed on the transition metal leakage, and a plurality of holes are formed in the thickness direction of the transition metal plate as a matrix, and rare earth metals are embedded in the holes. An embedded target is used.

However, alloy targets are prone to cracking during alloy production due to compositional non-uniformity and differences in thermal expansion and thermal contraction of transition metals and rare earth metals, and since the alloy target itself is extremely brittle, it is difficult to grind, polish, etc. It has the disadvantage that it is easily damaged by external force during processing, making it impossible to obtain a target with a desired large shape.

Furthermore, since transition metals and rare earth metals in the sintering target are metals that are easily oxidized, when these metals are powdered, oxides are generated on the surface of the metal powder. When sintered, the entire Kugend contains a large amount of oxide. Therefore, when the above-mentioned sintered Couget is sputtered to form an amorphous perpendicularly magnetized film, the oxide contained in the target is simultaneously sputtered and mixed into the magnetized film, resulting in an amorphous film with the desired characteristics. This method had the disadvantage that a perpendicularly magnetized film could not be obtained.

Furthermore, in the chip-on target, the composition of the amorphous perpendicular magnetization film to be formed is determined by the ratio of the exposed surface area of the transition metal plate to the exposed surface area of the rare earth metal piece (for example, 3:1) and the thickness of the rare earth metal piece. However, due to the collision of ions during rough sputtering, the side surface of the rare earth metal piece quickly decreases, resulting in severe changes in the surface a11 and J of the rare earth metal H'', resulting in amorphous vertical magnetization. It has the disadvantage that it is extremely difficult to control the composition of the film and that it is difficult to mass-produce.Since the cut rare earth metal piece ζ is a small piece, it becomes cantilevered when the magnetic force of the leakage magnetic field is applied. The exposed surface area of the rare earth metal piece changes, which changes the composition of the amorphous perpendicularly magnetized film, making it impossible to apply a large magnetic field with this chip-on target.
It also had the disadvantage of low efficiency of magnetron sputtering.

In fact, since the embedded target is a high-curiency single-point ferromagnetic material whose matrix transition metal has an angle of over 1000 degrees, it does not lose its magnetism even at a sputtering temperature of about 2000 degrees Celsius, and therefore remains permanently stable. The magnetic flux of the magnet passes through the transition metal that is the parent phase of the target, forming a so-called magnetic shield. Therefore, this embedded target has a small leakage magnetic field near the Kugut surface, which eliminates the drawback that the original function of the magnetron sputtering device cannot be fully demonstrated and high-speed film formation cannot be performed.

Zero-shot 8A was devised in view of the above-mentioned drawbacks, and its purpose is to capture and provide a large sputtering target that can form an amorphous perpendicularly magnetized film of a desired composition accurately and at high speed. .

The present invention provides a magnetron sputtering device for forming a leakage magnetic field near a target in order to generate an amorphous perpendicularly magnetized film mainly composed of rare earth metals and transition metals, in which the target has a matrix in contact with a cathode at 1f11, and a buried phase provided on the free surface side, the parent phase being made of at least one kind of rare earth metal, and the buried phase being made of at least one kind of transition metal.

Hereinafter, the present invention will be explained in detail based on embodiments shown in the accompanying drawings. FIG. 2 shows an embodiment of the sputtering target of the present invention, and the sputtering target, generally designated by 1 ( ), contains gadolinium (Gd), delbinicum (
Tb), Dysprosicum (Dy), Volmicum (Ho)
A matrix 11 consisting of rare earth metals such as cobal (Co),
It is composed of a buried phase 12 made of a transition metal such as iron (Fe). This 111 phase 11 is in surface contact with the cathode of the magnetron spankling device Δ, and the buried phase 12 is arranged on the free surface side opposite to the cathode.
It has a disc shape of 0 to 300 mm, and its upper surface 11
A cylindrical fitting hole 11b having an axis parallel to the axis of the matrix is formed on the a side (see FIG. 2(b)).

A buried phase 12 having the same shape as the fitting hole 11b is fitted into the fitting hole 11bK, and the upper surface 11a of the m-phase 11 and the upper surface 12a of the buried phase 12 are the same.

Incidentally, the surface area of the mother phase soil surface 11a and the buried phase upper surface 12
The surface area ratio with a is appropriately determined (usually a ratio of 1:3) in accordance with the desired composition of the amorphous perpendicularly magnetized film.

In the sputtering target of the present invention, it is important that a buried phase made of a transition metal is fitted into a parent phase made of a rare earth metal, and for this purpose, as shown in FIG. A columnar fitting hole 11b is formed, and a buried phase 12 made of a transition metal is fitted into the fitting hole 11b.

With a sputtering target having such a structure, a sputtering target can be manufactured by simply fitting a buried phase made of a transition metal into a parent phase made of a rare earth metal, and the metals of each phase are not brittle and have good workability. Since it has good properties, extremely large-sized products can be easily manufactured. Since the twisted embedded phase is fitted into the parent phase parallel to the axis of the parent phase, the ratio of the cross-sectional area of the parent phase and the embedded phase in the plane perpendicular to the axis of the target is always constant, and the sputtering Even if the target is used multiple times, the composition of the amorphous perpendicularly magnetized film that is formed can always be kept constant, making it extremely suitable for mass production.

As shown in Table 1, the rare earth metal in the parent phase has a single Curie point of less than 300 degrees, so the spanning Kugt temperature (approximately 200 degrees
In 'C), magnetism is completely lost, and the magnetism of the permanent magnet is not shielded by the parent phase, making it possible to make the leakage magnetic field in the vicinity of the target surface extremely large.

Therefore, ions generated by the glazma discharge can be efficiently collided with the target, making it possible to form an amorphous vertically magnetized film at high speed.

Table 1 Furthermore, although the rare earth metal of the parent phase is easily oxidized by the temperature of the parent phase itself and residual gas such as moisture contained in the sputtering atmosphere, the parent phase is in direct contact with the cathode.
Since the heat of the parent phase is well absorbed by the cathode and does not reach a high temperature, it is unlikely to undergo oxidation. Therefore, when an amorphous perpendicular magnetization film is formed by magnetron sputtering, no oxide is mixed into the amorphous east magnetization film, and an amorphous perpendicular magnetization film having desired characteristics can be formed.

As mentioned above, the sputtering target that is completely finished is extremely useful as it allows the production of extremely large lithium sputtering targets, as well as the ability to form an amorphous perpendicularly magnetized film with desired characteristics accurately and at high speed. .

It should be noted that the present invention is not limited to the above-mentioned embodiments,
For example, as shown in FIG. 3, a matrix 21 made of a rare earth metal
A fan-shaped fitting hole 21a is formed when viewed from above, and the fitting hole 2
1. A sector-shaped embedded phase 22 made of a transition metal may be fitted into the hole 31. Alternatively, a fitting hole 31a which is prismatic in plan view may be formed in the metal cover 31 made of a rare earth metal, as shown in FIG. A prismatic embedded phase 32 made of a transition metal may be fitted into the fitting hole 31a. In this case, the surface area ratio between the parent phase and the buried phase on the upper surface of the target is appropriately determined in accordance with the desired composition of the amorphous perpendicularly magnetized film.

[Brief explanation of the drawing]

FIG. 1 is a block diagram for explaining the conventional magnetron sputtering method, FIG.
FIG. 2(b) is a sectional view taken along the line A-A in FIG. 2(a), FIG. 3(a) is a plan view of a sputtering target showing another embodiment of the present invention, and FIG. 3(b) is a plan view of a sputtering target showing another embodiment of the present invention. B-B in Figure 3(a)
4(a) is a plan view of a sputtering target showing still another embodiment of the present invention, and FIG. 4(b) is a sectional view taken along the line C--C of FIG. 4(a). 1.1, 21.31...matrix, 12,22.32...
・Embedded phase, llb, 21a, 31a - Fitting hole agent Patent attorney Kei Nishi Part Figure 1 Figure 2 (a) 2 (b) Figure 3 (b) Section 4 (a) (b)

Claims (1)

[Claims] In a magnetron sputter link device that forms a leakage magnetic field near a target in order to generate an amorphous perpendicularly magnetized film mainly composed of rare earth metals and transition metals, the target has a parent phase in surface contact with the cathode and a free surface side. 1. An embedded composite target comprising: an embedded phase provided in the target; the parent phase is composed of at least one kind of rare earth metal; and the embedded phase is composed of at least one kind of transition metal.