JPH056334B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to a method for manufacturing a magnetic thin film used as a recording medium in a perpendicular thermomagnetic recording system.

The perpendicular thermomagnetic recording method involves forming a perpendicularly magnetizable recording medium made of a magnetic thin film on a base material made of a non-magnetic material such as glass, ceramics, or plastic, and irradiating the surface of the recording medium with a laser beam to detect the irradiated area. Thermomagnetic In order to read the information, another linearly polarized laser beam is applied to the surface of the recording medium, and the reflected light from the surface is optically detected via an analyzer. That is, since the plane of polarization of the laser beam is rotated by the Kerr effect at the position of the recording medium where information is written,
During readout, the rotation of the plane of polarization is detected. The rotation angle of the above polarization plane is the Kerr rotation angle Θk
Say.

Gd--Fe amorphous alloys have conventionally been used as a material for magnetic thin films constituting the recording medium.
Recently, Bi was further added to the Gd-Fe amorphous alloy, and Gd
−Fe−Bi amorphous alloy with increased Θk and good
It was found that the signal-to-noise ratio could be obtained. The Gd-Fe-
To form a magnetic thin film made of a Bi amorphous alloy, as shown in FIG.
A conceivable method is to sputter a Gd-Fe-Bi alloy by sputtering the Gd-Fe-Bi alloy by charging the Gd-Fe-Bi amorphous alloy layer on the base material. However, the melting point of Bi is low (271.3 DEG C.), and if the composite target 10 is used, Bi will melt during sputtering, making it impossible to obtain a Gd--Fe--Bi amorphous alloy layer with a predetermined composition. However, the Gd-Fe-Bi alloy is extremely brittle and cannot be used as a single target. Furthermore
Gd-Fe alloys are similarly brittle and cannot be used as target elements.

The present invention aims to solve the above conventional problems, and is a method for manufacturing a magnetic thin film made of a Gd-Fe-Bi amorphous alloy by sputtering a composite target made of Gd, Fe, and Bi onto a base material. In,
The composite target is a combination of an element made of Gd-Bi alloy and an element made of Fe, or
The main feature is that it is composed of a combination of an element made of Fe-Bi alloy and an element made of Gd.

In the present invention, according to the above outline, Gd, Fe, Bi
In a complex target consisting of
Gd-Bi alloy or Fe-Bi alloy is used, and these alloys have a high melting point and are not brittle, so they are easy to handle, and there is no single Bi element with a low melting point or Gd-Fe alloy element, which is brittle and difficult to handle. A magnetic thin film made of a Gd-Fe-Bi amorphous alloy with a composition of 1 can be easily obtained by sputtering.

The invention will be explained in detail below.

An embodiment of the composite target of the present invention is shown in FIG. The composite target 20 includes a disk-shaped substrate 11.
and a small piece 12 arranged on the substrate 11. In the present invention, each element has the following composition.

Substrate 11 Small piece 12 Case 1 Fe Gd-Bi 2 Gd-Bi Fe 3 Gd Fe-Bi 4 Fe-Bi Gd As mentioned above, in all cases, there is no Bi element with a low melting point or a brittle Gd-Fe element. . And the Gd-Bi alloy is not brittle and its melting point is
975°C or higher, and the Fe-Bi alloy is also not brittle and has a melting point almost the same as Fe. Therefore, the composite target 20 according to the present invention is used as a back plate of the electrode 22 in the sputtering chamber 21 as shown in FIG. 22A and supported by a holder 24 through a shutter 23, and after replacing the inside of the chamber 21 with an inert gas such as argon gas or neon gas through a ventilation hole 26, the electrode 22 When the composite target 20 is charged and the shutter 23 is opened, Gd-Fe- of a predetermined composition is deposited on the surface of the base material 25.
A Bi amorphous alloy layer is sputtered. Note that the base material 25 may be plastic, ceramics,
Materials such as glass are used.

In addition to the above embodiments, if a predetermined number of fitting holes are provided on the surface of the substrate 11 in the composite target and the small pieces 12 are brought into close contact with the fitting holes, sputtering can be advantageously performed without the small pieces 12 shifting on the substrate 11. obtain.

[Brief explanation of drawings]

Figure 1 is a perspective view of a conventional composite target, Figure 2 is a perspective view of a conventional composite target;
The figure is a perspective view of an embodiment of the composite target of the present invention, and FIG. 3 is an explanatory view of sputtering. In the figure, 11... substrate, 12... small piece, 20...
Composite target.

Claims (1)

[Claims] 1. A method for producing a magnetic thin film made of a Gd-Fe-Bi amorphous alloy by sputtering a composite target made of Gd, Fe, and Bi onto a base material, in which the composite target is made of an element made of a Gd-Bi alloy.
Combination with element consisting of Fe or Fe-
1. A method for producing a magnetic thin film, characterized in that it is constructed by a combination of an element made of Bi alloy and an element made of Gd.