JP2003173588A - Manufacturing method for magnetooptic disk by inductively coupled rf plasma supported magnetron sputtering method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a magnetooptic disk which can form a magnetooptic recording film of small particle size enough for good magnetic field sensitivity and high-density recording by using an inductively coupled RF plasma supported magnetron sputtering device. <P>SOLUTION: The inductively coupled RF plasma supported magnetron sputtering device which has a magnetic circuit 10 provided on the reverse surface of at least one cathode electrode 9, a target 12 mounted on the top surface of each cathode electrode 9, and a helical coil 14 provided so as to surround the space between the target 12 and a substrate 7 and can superposes RF electric power on the coil 14 is used to form the magnetooptic recording film on the substrate 7. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a magneto-optical disk.

[0002]

2. Description of the Related Art A conventional apparatus for manufacturing a magneto-optical disk has a vacuum chamber A as shown in FIG. 4 of the accompanying drawings.
The vacuum chamber A is connected to the exhaust system B and the gas supply system C. In the vacuum chamber A, a substrate holder D and a cathode electrode E are arranged to face each other, a substrate F to be processed is mounted on the substrate holder D, and a mask G is mounted thereon. On the other hand, the cathode electrode E is connected to the power source H,
A magnetic circuit I is mounted on the back side of the cathode electrode E, and a target J is mounted on the front side of the cathode electrode E.
In addition, K is an earth shield.

In the rare earth / transition metal multi-source sputtering, a circular self-revolving sputtering apparatus tray L as shown in FIG. 5 is used, and a plurality of substrate holders M are provided on the tray L. The substrate is passed over the target several times to several tens of times, whereby the film is formed.

Although there are some improvements in magnetic field sensitivity such as composition and SiN etching and oxidation treatment, there is no conventional example in which a magneto-optical disk is manufactured using an inductively coupled RF plasma assisted magnetron sputtering apparatus. In order to achieve the next-generation high recording density in a magneto-optical disk, it is necessary to further improve the so-called magnetic field sensitivity, which allows complete rewriting even with a relatively weak external magnetic field. In the conventional film forming method, this magnetic field sensitivity is poor, and a sufficiently low jitter characteristic has not been obtained. Further, the surface property of the film was poor and the particle size required for high density recording was not sufficiently reduced.

[0005]

Therefore, the present invention uses an inductively-coupled RF plasma assisted magnetron sputtering apparatus to form a magneto-optical recording film having a good magnetic field sensitivity and a sufficiently small grain size suitable for high density recording. It is an object of the present invention to provide a method for manufacturing a magneto-optical disk capable of forming a film.

[0006]

In order to achieve the above object, in the method of manufacturing a magneto-optical disk according to the present invention, a magnetic circuit is provided on the back surface of at least one cathode electrode, and a target is mounted on the surface of each cathode electrode. Then, a coil is provided to surround the space between the target and the substrate, and the coil is
It is characterized in that a magneto-optical recording film is formed on a substrate by using an inductively coupled RF plasma assisted magnetron sputtering device capable of superposing F power.

The target for the magneto-optical recording film is an alloy or T
It is made of a rare earth element such as b, Dy, or Gd and a transition metal such as Fe or Co, and can be made to perform multi-source sputtering.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3 of the accompanying drawings. FIG. 1 shows an example of an inductively coupled RF plasma assisted magnetron sputtering apparatus implementing the method of the present invention. In FIG. 1, reference numeral 1 is a vacuum chamber, which constitutes a sputtering chamber. To the vacuum chamber 1, an exhaust system 2 capable of exhausting the vacuum chamber 1 to a required level and a gas supply system 3 for supplying a sputtering gas into the vacuum chamber 1 are connected.

A substrate holder 4 is arranged in the vacuum chamber 1, and the substrate holder 4 is configured to be rotationally driven by a motor 6 provided outside the vacuum chamber 1 via a shaft 5. Alternatively, the substrate 7 to be film-formed is mounted on the surface of the substrate holder 4.

A pair of cathode electrode assemblies 8 are arranged facing the substrate holder 4 arranged in the vacuum chamber 1 at an angle toward the center of the substrate holder 4.
Each cathode electrode assembly 8 includes a cathode body 9, a magnetic circuit 10 provided on the back side of the cathode body 9, and a target 12 mounted on the surface of the cathode body 9 via a backing plate 11, The main body 9 is connected to the power supply 13. The magnetic circuit 10 is the target 1
A magnetron magnetic field is formed along the surface of 2. Further, between each cathode electrode assembly 8 and the substrate 7, a helical coil 14 is arranged coaxially with the central axis of each cathode electrode assembly 8, and each helical coil 14 is connected to an RF power source 15 and RF. Power supply 15 is 13.5
Apply high frequency power of 6MHz to the helical coil 14,
High-density plasma is generated in the space surrounded by the helical coil 14. As a result, the processing gas introduced into the vacuum chamber 1 can be efficiently ionized.

[0011]

[Embodiment] An MPS-2000 type apparatus manufactured by ULVAC, Inc. is used, and the apparatus is provided in a charging chamber, an intermediate chamber and a sputtering chamber
It consists of 3 rooms. The sputtering chamber was constructed as shown in FIG. 1, and a Si wafer was used as the substrate 7.

A polycarbonate substrate is used at the time of evaluating the drive characteristics, and the film structure is as shown in FIG. 2 on a PC (polycarbonate substrate) 16 on a SiN reflection layer 17 / TbFeC.
Evaluation was made with a four-layer structure of dielectric layer 18 / SiN recording film 19 / AlTi dielectric layer 20.

The substrate holder 4 is driven by a motor 6
It was rotated at pm. 13.5 for each helical coil 14
6MHz is superimposed, and the target 12 is Si, Tb, F
eCo and AlTi were used. The SiN dielectric film 17 is S
Ar and N ₂ gas were introduced into the i target 12 from the gas supply system 3 to form a film by the reactive sputtering method. The film forming pressure was set from 0.1 Pa to 1 Pa, and a DC power supply 13 was connected to the cathode body 9 of each cathode electrode assembly 8 to carry out.

Table 1 shows the power dependence of the surface smoothness of the rare earth / transition metal alloy film made of Tb / FeCo on the coil 14. Table 1 Power to coil 14 (W) 0 60 120 Ra (nm) 0.146 0.123 0.107 As shown in Table 1, by applying power to coil 14, Ra becomes smaller, and 120 W than 60 W. It is recognized that the Ra is further reduced by the application of the electric power of 1, the surface property of the film is improved, and a smooth surface suitable for high density recording is obtained.

FIG. 3 shows drive characteristics in the case of the film structure shown in FIG. As shown in FIG. 3, the magnetic field sensitivity was improved by superimposing RF on the coil 14, and it was confirmed that the characteristics suitable for high density recording were obtained.

By the way, in the illustrated embodiment, a pair of cathode assemblies are used, but naturally one or more cathode assemblies can be incorporated in the sputtering chamber. Further, the helical coil provided between the substrate and the target can be provided outside the sputtering chamber. In that case, the wall of the sputtering chamber in which the helical coil is provided is made of a dielectric or an insulator. Further, instead of the illustrated apparatus, the film forming apparatus proposed in Japanese Patent Application Laid-Open No. 6-41739 filed by the applicant of the present application may be used in the present invention.

[0017]

As described above, in the method of manufacturing a magneto-optical disk according to the present invention, a magnetic circuit is provided on the back surface of at least one cathode electrode, and a target is mounted on the surface of each cathode electrode. A coil is provided so as to surround a space between the substrate and the magneto-optical recording film is formed on the substrate by using an inductively coupled RF plasma assisted magnetron sputtering device capable of superposing RF power on the coil. As a result, the magnetic field sensitivity can be improved, and a magneto-optical recording film having characteristics suitable for high density recording can be formed.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of an inductively coupled RF plasma assisted magnetron sputtering apparatus that can be used to carry out the method of manufacturing a magneto-optical disk of the present invention.

FIG. 2 is a diagram showing a disk configuration to which the magneto-optical disk manufacturing method of the present invention is applied.

FIG. 3 is a graph showing drive characteristics in the method for manufacturing a magneto-optical disk of the present invention.

FIG. 4 is a schematic diagram showing a structure of a sputtering chamber in a conventional single-wafer sputtering apparatus.

FIG. 5 is a schematic diagram showing a circular rotating and orbiting sputtering apparatus tray in a conventional apparatus.

[Explanation of symbols]

1: Vacuum chamber 2: Exhaust system 3: Gas supply system 4: Board holder 5: axis 6: Motor 7: Substrate 8: Cathode electrode assembly 9: Cathode body 10: Magnetic circuit 11: Backing plate 12: Target 13: Power supply 14: Helical coil 15: RF power supply

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Noriaki Tani             523 Yokota, Sanmu-cho, Sanmu-gun, Chiba Prefecture             Lubac Chiba Institute for Materials Research (72) Inventor Hiroaki Kawamura             523 Yokota, Sanmu-cho, Sanmu-gun, Chiba Prefecture             Lubac Chiba Institute for Materials Research (72) Inventor Akira Ishibashi             523 Yokota, Sanmu-cho, Sanmu-gun, Chiba Prefecture             Lubac Chiba Institute for Materials Research (72) Inventor Satoshi Miura             2500 Hagien, Chigasaki City, Kanagawa Prefecture Co., Ltd.             In ULVAC F term (reference) 4K029 AA11 AA24 BA24 BA26 BA52                       BB02 BC06 BD12 CA05 CA06                       DC39                 5D075 FF04 GG03 GG12

Claims (2)

[Claims] 1. A magnetic circuit is provided on the back surface of at least one cathode electrode, a target is mounted on the surface of each cathode electrode, a coil is provided so as to surround a space between the target and the substrate, and RF power is superposed on the coil. A method for manufacturing a magneto-optical disk, which comprises depositing a magneto-optical recording film on a substrate by using an inductively coupled RF plasma assisted magnetron sputtering apparatus capable of performing the above. 2. A target for a magneto-optical recording film is an alloy or T
The multi-element sputtering is performed, which is made of a rare earth element such as b, Dy, or Gd and a transition metal such as Fe or Co, and performs multi-source sputtering.
A method for manufacturing a magneto-optical disk according to.