JPH01130321A - Production of magnetic disk - Google Patents

Abstract

PURPOSE:To improve magnetic characteristics by providing at least plural sets of targets for forming underlying films and forming the underlying films as multiple layers, thereby changing the particle shape so as to approximate the same to a columnar shape. CONSTITUTION:The underlying films 26, 27 are formed as the multiple layers by using at least plural sets of the targets 22-25 at the time of producing a magnetic disk. The grain constitution to constitute the underlying films 26, 27 is, therefore, approximated to the columnar shape in the section viewed from the direction perpendicular to the carrying direction of a disk substrate. The magnetic anisotropy is made small and the difference in the coercive force Hc in the carrying direction and the direction perpendicular thereof of the disk substrate is lessened. The reproduced output at the time of reproduction is thereby fluctuated to a lesser extent and the modulation and noises are sufficiently suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing a magnetic disk in which a base film, a magnetic recording film, and a protective film are formed by an in-line sputtering method.

(Prior Art) Conventionally, attempts have been made to manufacture metal thin film type magnetic disks using, for example, an in-line type sputtering apparatus as shown in FIG.

In FIG. 3, reference numeral 1 denotes a vacuum container constituting the sputtering apparatus.
a pair of first targets 2 and 3 for forming a film);
A pair of second targets 4.5 for forming a magnetic recording film (for example, C0NiCr film) and a pair of third targets 6.7 for forming a protective film (for example, C film) are indicated by arrow A. They are sequentially stored in the transport direction of the disk substrates shown.

In the sputtering apparatus configured in this way, first, C.
Annular magnetron sputtering is performed using r targets 2 and 3 to cause Cr particles to fly to form a Cr film 9 as a base film of a predetermined thickness on the substrate 8, and then CON r is deposited on this Cr film 9. Annular magnetron sputtering is performed using Cr targets 4 and 5 to cause CON i Cr particles to fly to form a C0NiCr film 10 to a predetermined thickness, which will become a magnetic recording film. Magnetron sputtering is performed to make carbon particles fly and form a carbon film 11 to a predetermined thickness on the CoNiCr film 10 (see FIGS. 4 and 5).

In this way, a magnetic disk is manufactured.

(Problems to be Solved by the Invention) However, in such a conventional magnetic disk manufacturing method, the film cross section of the manufactured magnetic disk has a grain structure as shown in FIGS. 4 and 5. It became. That is, as shown in FIG. 4, in a cross section viewed from a direction perpendicular to the transport direction of the disk substrate (see arrow A), the Cr particles 9A of the Cr film 9 and the C0NiCr particles 10A of the CoNiCr film 10 have an arcuate shape. On the other hand, as shown in FIG. 5, in a cross section taken along the disk substrate transport direction (■ mark B, see), the Cr particles 9B of the Cr film 9 and the CoNiCr film 10 are curved. The CoN i Cr particles 10B have a columnar shape.

As described above, since the shapes of the Cr particles 9A, 9B and the CoNiCr particles 10A, 10B are different in the transport direction of the disk substrate and in the direction perpendicular thereto, the magnetic anisotropy becomes large. As a result, the difference (ΔHc) between the coercive force Hc in the transport direction of the disk substrate and in the direction perpendicular to the disk substrate becomes large, resulting in a problem that the reproduction output fluctuates during reproduction and modulation and noise become large.

(Means for Solving the Problems) The present invention has been made in view of such conventional problems. It is an object of the present invention to provide a method for manufacturing a magnetic disk in which the particle shape is changed to be closer to a columnar shape by forming a base film, thereby improving magnetic properties.

To achieve this object, the present invention provides a method for manufacturing a magnetic disk in which a base film, a magnetic recording film, and a protective film are formed on a substrate by a sputtering method, in which at least a plurality of sets of targets are used to form a multilayer film. The base film is formed.

(Function) In the present invention, since at least a plurality of sets of targets for forming the base film are provided to form the base film in multiple layers, the bottom film is The grain structure that makes up the earth's membrane approaches a columnar shape.

Therefore, the magnetic anisotropy is reduced, and the difference in coercive force HC between the disk substrate conveying direction and the direction perpendicular thereto becomes small. As a result, fluctuations in the reproduction output during reproduction are reduced, and modulation and noise can be sufficiently suppressed.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a diagram showing an in-line sputtering apparatus for implementing the present invention.

First, to explain the apparatus, in FIG. 1, reference numeral 21 is a vacuum vessel constituting an in-line sputtering apparatus, and the inside of this vacuum vessel 21 is maintained at a predetermined degree of vacuum.

Inside the vacuum container 21, there are directions in the transport direction of the disk substrate (arrow A,
(see), a set of first targets 22, 23 and a set of second targets 24, 25 are respectively installed. The first targets 22 and 23 are for forming, for example, a first Cr film 26, which will be a base film, and the second targets 24 and 25 are for forming a second Or film 27, which will be a base film. be.

Next, in the vacuum container 21, following the second target 24, 25, there are a negative set of third targets 28, 29 and a set of fourth targets 30, 31 in the transport direction of the disk substrate.
will be installed. The third targets 28 and 29 are for forming the first CONiCr film 32, which will become a magnetic recording film, and the fourth targets 30 and 31 are for forming the second CoN i Cr film 33, which will become a magnetic recording film. belongs to.

Next, in the vacuum chamber 21, a set of fifth targets 34, 35 are provided following the fourth targets 30, 31 in the transport direction of the disk substrate. 5th target 34.35
is for forming a protective film, for example, a C film. Note that the first and second targets 22 to 25 and the third
．． The fourth targets 28 to 31 are placed at intervals of, for example, 10 cm. Also, 1st. Second target 22
~25 and 3rd. Although two sets of the fourth targets 28 to 31 are installed here, the present invention is not limited to this, and it is more effective to install two or more sets of the fourth targets 28 to 31.

Next, a manufacturing method for manufacturing a magnetic disk using the above-described in-line sputtering apparatus will be described.

First, the substrate 36 is transported into the vacuum container 21 along the transport direction shown by arrow A. As the substrate 36, a disk-shaped glass plate is used, which is free from scratches and has superior smoothness than an aluminum substrate.

Next, annular magnetron sputtering is performed using Cr from the first target 22, 23 to make Cr particles fly, and a 10r film 2 of a predetermined thickness is formed on the substrate 36 to become a base film.
6 is formed on this first Cr film 26, and then annular magnetron sputtering is performed using Cr on this first Cr film 26 to cause Cr particles to fly from the second target 24, 25 to form a second Cr film 27 of a predetermined thickness that will become a base film. Form.

Next, annular magnetron sputtering is performed on the second Or film 27 using C0NiCr to form a third target 28.2.
9 to form a first CoNiCr particle 32 of a certain thickness which will become a magnetic recording film, and
Perform annular magnetron sputtering using ONiCr on the fourth target from 30°31 to C0NlCr.
A 20th film of a predetermined thickness that becomes a magnetic recording film by flying particles
An ON + Cr film 33 is formed.

First, annular magnetron sputtering is performed using C on the second CON r CR film 33 to form a fifth target 34.
．． C particles are made to fly from C particles 35 to form a C film 37 that serves as a protective film with a predetermined thickness. In this way, a magnetic disk is manufactured.

A film cross section of the manufactured magnetic disk is shown in FIG.

In FIG. 2, the first Cr film 26 and the second Or film 27 constitute a Cr film 38 as a whole, and the first CONiC
The r film 32 and the second CON+CR film 33 are CO as a whole.
A N i Qr film 39 is formed.

The first Cr particles 26A and the 20th Cr particles constituting the first Cr film 26
The 20th r particles 27A constituting the r film 27 are each formed in a small arch shape, but the first Cr particles 26A and the 20th Cr particles 27A
The shape of the entire Cr particle in which the r particles 27A are laminated is the fifth
The Cr particles 9B shown in the figure approach a columnar shape as shown. That is, the Cr film 38 is divided into multiple layers. 2nd Or
Since it is composed of particles 26A and 27A, the more it is divided into multiple layers, the closer the shape of the Cr particles becomes to a linear columnar shape.

Similarly, the first CON that constitutes the first CONiCr film 32
The entire C'oNiCr particles in which the iCr particles 32A and the second CoN i Cr particles 33A constituting the second CON r cr film 33 are stacked are the CON i Cr particles shown in FIG.
It approaches a columnar shape as shown by the r particle 10A.

That is, the grain structure in the cross section of the film viewed from the direction perpendicular to the transport direction of the disk substrate, indicated by arrow A in FIG. 2, is close to the grain structure shown in FIG. 5.

Therefore, the magnetic anisotropy becomes smaller, and the coercive force HC is the difference (
ΔHC) becomes small, and fluctuations in reproduction output during reproduction become slight. As a result, modulation and noise can be sufficiently suppressed.

Note that in this embodiment, the third. 4th target 28
31 is provided to divide the C0NiCr film 39, but it is not necessarily necessary to divide the Cr film 38.

(Effects of the Invention) As explained above, according to the present invention, at least a plurality of sets of targets are provided to divide the Cr film serving as the base film into a plurality of sets, so that the grain structure of the Cr film approaches a columnar shape. be able to. Therefore, the magnetic anisotropy becomes smaller, the difference in coercive force in the direction perpendicular to the transport direction of the disk substrate becomes smaller, and fluctuations in reproduction output during reproduction become smaller. As a result, modulation and noise can be sufficiently suppressed.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an in-line sputtering apparatus used to carry out the present invention, FIG. 2 is a half-sectional view showing a film cross section of a magnetic disk manufactured by the manufacturing method according to the present invention, and FIG. 3 is a conventional A schematic diagram of an in-line sputtering apparatus used to carry out the manufacturing method, and FIGS. 4 and 5 are half sectional views showing the film cross section of a magnetic disk manufactured by the conventional manufacturing method. 21... Vacuum vessel, 22.23... First target, 24.25... Second target, 26... First Cr film, 27... Second Cr film, 28.29... Second target. 3 target, 30.31... Fourth target, 32-... First CONiCr film, 33-... Second CoNiCr film, 34.35... Fifth target, 36... Substrate, 37... - C film (protective film), 3B-Crtl@ (base film), 39... CoNiCr film (magnetic recording film). Patent applicant: Nippon Sheet Glass Co., Ltd. Representative Patent attorney: Sabetsu Miyauchi

Claims (1)

[Claims] A magnetic disk manufacturing method in which a base film, a magnetic recording film, and a protective film are formed on a substrate by a sputtering method, characterized in that the base film is formed in a multilayered manner using at least a plurality of sets of targets. Disc manufacturing method.