JPH0482016A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve a reproduced output and recording density by using a gaseous mixture composed of gaseous Ar and gaseous oxygen at the time of forming an underlying film of Cr. CONSTITUTION:The underlying film of the Cr is formed by using the gaseous mixture composed of the gaseous Ar and the gaseous oxygen as an atmosphere at the time of producing the magnetic recording medium formed with the underlying film and magnetic film consisting of CoCrTa or CoNiCr by a sputtering method on a substrate. The magnetic film thereof is formed by using the gaseous Ar as the atmosphere. Namely, the gaseous oxygen in addition to the gaseous Ar of the prior art exist at the time of the formation of the underlying film, by which the quality and structure of the underlying film are changed and the quality and structure of the magnetic film to be formed next are eventually influenced. The magnetic characteristics are improved in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a magnetic recording medium, and more particularly to a method of manufacturing a longitudinal magnetic recording medium for a hard magnetic disk.

[Prior Art] As a high recording density medium for hard magnetic disks, thin film media produced by sputtering have now become mainstream instead of coated media. In order to achieve high recording density, this thin film medium is required to have high output and high recording density characteristics. In order to improve these characteristics, the magnetic properties of the medium need to be large, such as coercive force (HC), squareness ratio (S), and more specifically coercive force squareness ratio (S 2 ).

Therefore, in order to obtain the above characteristics, a NiP/8 substrate with textured grooves in the circumferential direction of the disk was used as a substrate, and a Cr film was deposited as an underlayer film on the substrate by sputtering using pure A gas. , a method has been proposed to fabricate a medium by forming a CONiCr film or a CoCrTa film as a magnetic film (IEICE technical research report, CPM
8B-91 and CPM8B-92, 1988).

[Problems to be Solved by the Invention] Although the coercive force, squareness ratio, and coercive force squareness ratio of the medium are at good levels even in the above-mentioned conventional thin film medium manufacturing technology using the sputtering method, it is still difficult to realize ultra-high recording density. We need to improve them.

Another object of the present invention is to provide a method for manufacturing a magnetic recording medium with particularly improved coercive force in order to realize ultra-high recording density.

[Means for Solving Problem 11] The present invention provides a method for forming a base film of Cr on a substrate using a sputtering method.
In a method for manufacturing a magnetic recording medium in which oCrTa or CoN i Cr(7) magnetic films are sequentially formed, the base film is A.
This method of manufacturing a magnetic recording medium is characterized in that a mixed gas consisting of r gas and oxygen gas is formed as an atmosphere, and a magnetic film is formed as an atmosphere of Ar gas.

[Function] In the present invention, when producing a magnetic recording medium in which a Cr base film and a CoCrTa or CON i Cr magnetic film are formed on a substrate by sputtering, the base film is a mixture of Ar gas and oxygen gas. The magnetic properties can be improved by forming the magnetic film using Ar gas as the atmosphere.

That is, according to the manufacturing method of the present invention, the presence of oxygen gas other than the conventional Ar gas during the formation of the underlayer changes the film quality and structure of the underlayer, and this causes a change in the magnetic film to be deposited next. It also affects the film quality and structure of the film, and as a result, the magnetic properties are improved.

[Example] Examples of the present invention will be described below.

Example 1 In this example, a case where the magnetic film is a CoCrTa film will be described. The sputtering apparatus used in this example is of the RF magnetron type. The target is a Cr target with a purity of 3N for the base film, and a Co target for the magnetic film.
CrTa (12 at% Cr:, 2 at% Ta) alloy targets were used. In addition, the substrate is smooth (Rm
ax-20 people> A glass substrate was used.

First, Table 1 shows sputtering conditions according to Example 1 of the present invention. For comparison, Comparative Example 1 is a medium in which pure Ar gas was used during the formation of the Cr underlayer film as in the prior art.

The magnetic properties of these two types were measured using a vibrating sample magnetometer (VSM). The results are shown in Table 2. From this, it can be seen that the medium of the present invention has improved magnetic properties, particularly coercive force, compared to the conventional media.

Table 1 Table 2 Example 2 Next, a case where the magnetic film is a CoN i Cr film will be described. Here, CON i Cr (20at
%N i , 10at%cr>The base film target and substrate were the same as in Example 1 except that an alloy target was used. In addition, the sputtering conditions are as shown in Table 3.
It is the same as Example 1 except for CoNiCr. For comparison, pure Ar was also used when forming the Qr base film as in the conventional case.
Comparative Example 2 is a medium prepared using gas.

Table 4 shows the measurement results of the magnetic properties of these two types by VSM. From now on, the medium of this example will also be used as Example 1.
Similarly, it can be seen that the magnetic properties, especially the coercive force, have been improved compared to the conventional one.

(Substrate, Cr"l reverse sputtering) Table 3 (substrate.

(With reverse sputtering of Cr film) Table 4 [Effects of the invention] As explained above, the magnetic recording medium manufactured by the manufacturing method of the present invention is produced by using a mixed gas of Ar gas and oxygen gas during the formation of the Cr underlayer film. By using this material, the magnetic properties, especially the coercive force, were improved compared to the conventional method, and the reproduction output, recording density, etc. were further improved compared to the conventional method.

Claims (1)

[Claims] (1) Cr base film and CoC on the substrate by sputtering method
A method for manufacturing a magnetic recording medium in which magnetic films of rTa or CoNiCr are sequentially formed, characterized in that the base film is formed in an atmosphere of a mixed gas of Ar gas and oxygen gas, and the magnetic film is formed in an atmosphere of Ar gas. A method for manufacturing a magnetic recording medium.