JPH09320135A - Production of magnetic-optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease the production time and the production cost by sputtering an alloy target with a mixture gas of Ar gas and Kr gas or Ar gas and Xe gas to form an amorphous magnetic layer. SOLUTION: A sheet-type magnetron sputtering device 2 is used, in which a SIALON sintered body is used as the target for a dielectric layer 4, a Tb-Fe- Co alloy is used as the target for an amorphous magnetic layer 5, a SIALON sintered body is used as the target for a dielectric layer 6, and an Al alloy is used as the target 13 for a reflection layer 7. Ar gas and Kr gas are introduced through an inlet 14 and each target is sputtered to form a dielectric layer 4, amorphous magnetic layer 5, dielectric layer 6, and reflection layer 7 on a substrate 3 to obtain a magneto-optical recording medium 1. Moreover, the amt. of Fe can be decreased, similarly as in the case when Xe is used, to control the coercive force.

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 recording medium in which an amorphous magnetic layer composed of a rare earth metal and a transition metal is formed by sputtering.

[0002]

2. Description of the Related Art An amorphous magnetic layer of a rare earth metal and a transition metal is formed by sputtering using argon gas. When an alloy of a rare earth metal and a transition metal is used as the target, By changing the composition ratio of the alloy or the area of the target, the composition ratio of the formed amorphous magnetic layer is set to a required value.

[0003]

However, in such sputtering, even if the target alloy composition is set to a required ratio, if the film formation time is prolonged, the composition ratio of the formed layer changes or varies. Therefore, the film formation is temporarily stopped and replaced with a new target. Therefore,
The exchange took time and the cost of the target increased.

On the other hand, even if an attempt is made to obtain a desired film-forming composition ratio by changing the sputtering area of the target, there is a problem in that the film formation varies and the film thickness and composition ratio vary.

Further, the amorphous magnetic layer as described above tends to be corroded extremely easily. For that reason, although the material has been improved and developed up to now, in recent years, the magnetic layer which is further excellent in corrosion resistance. Is desired.

Therefore, the present invention has been completed in view of the above circumstances, and an object thereof is to prevent the replacement of a new target in the middle of film formation, thereby shortening the manufacturing time,
Further, it is to reduce the manufacturing cost.

Another object of the present invention is to provide a high-quality and highly reliable light which is excellent in corrosion resistance, has no variation among individual products, and has uniform performance over the film surface even within the products. It is to provide a magnetic recording medium.

[0008]

According to the method of manufacturing a magneto-optical recording medium of the present invention, an alloy target composed of a rare earth metal and a transition metal of Fe and Co is used as a mixed gas of Ar gas and Kr gas or Ar gas and Xe. It is characterized in that an amorphous magnetic layer is formed into a film on a substrate by sputtering with a mixed gas with a gas.

Another method of manufacturing the magneto-optical recording medium of the present invention is characterized in that the film formation by the above-mentioned sputtering is carried out by using a single-wafer type magnetron sputtering apparatus.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 shows a layer configuration of a magneto-optical recording medium 1 according to the manufacturing method of the present invention, and FIG. 2 shows a schematic configuration of a single-wafer magnetron sputtering apparatus 2 for forming a film on the magneto-optical recording medium 1.

In FIG. 1, reference numeral 3 denotes a substrate made of a resin such as polycarbonate. On one side of the substrate 3, a dielectric layer 4 made of, for example, sialon and an amorphous GdD are provided.
A magneto-optical recording layer 5 made of a yFeCo alloy, a TbFeCo alloy, etc., a dielectric layer 6 made of sialon, etc., and a reflection layer 7 are sequentially laminated by a sputtering method, and a protection layer made of an acrylic resin is further provided on the reflection layer 7. A resin layer (not shown) is formed by coating.

The dielectric layers 4 and 6 may be formed of silicon oxide, aluminum nitride, titanium oxide, tantalum oxide, etc. other than sialon. The reflection layer 7 is made of Al, T
It is formed of at least one metal or alloy of i, Au, Ag, Cu, Pt, Cr, and Ni.

Next, the basic structure of the single-wafer type magnetron sputtering apparatus 2 will be described with reference to FIG. Reference numeral 8 denotes a vacuum chamber. A rotatable substrate support 9 is disposed in the center of the vacuum chamber 8, and the substrate 3 is fixed to one surface of the substrate support 9. A target 10 for the dielectric layer 4, a target 11 for the amorphous magnetic layer 5, a target 12 for the dielectric layer 6, and a target 13 for the reflective layer 7 are provided on the four side walls of the vacuum chamber 8. And, a power application system for applying power between each of the targets 10, 11, 12, 13 and the substrate support 9 is provided. Furthermore, inlets 14 for a mixed gas of Ar gas and Kr gas or a mixed gas of Ar gas and Xe gas are formed at the four corners. An exhaust port (not shown) for discharging the residual gas after the film formation is also provided.

In order to form each layer into a film by the single-wafer type magnetron sputtering device 2 having the above-mentioned structure, the substrate 3 is fixed to the substrate support 9 and the inside of the vacuum chamber 8 is evacuated. Next, a mixed gas is introduced from the four inlets 14, and power is applied between the substrate support 9 and the target 10 for the dielectric layer 4 to form the dielectric layer 4 on the substrate 3. The substrate support 9 is rotated by 90 degrees to apply electric power between the substrate support 9 and the target 11 for the amorphous magnetic layer 5, thereby forming the amorphous magnetic layer 5 into a film. The body layer 6 and the reflection layer 7 are formed to manufacture the magneto-optical recording medium 1. Thereafter, the inside of the vacuum chamber 8 is returned to the atmospheric pressure, and the magneto-optical recording medium 1 is taken out.

When forming the amorphous magnetic layer 5 of the magneto-optical recording medium 1, a mixed gas of Ar gas and Kr gas or a mixed gas of Ar gas and Xe gas is used as a sputtering gas. , And Ar gas and K
By utilizing the difference in the sputtering rates of Fe / Co from the r gas (or Xe gas) and changing the gas ratios thereof, it is possible to set each atomic ratio as required.

Thus, according to the manufacturing method of the present invention, only Ar
The composition ratio of the layer can be adjusted by changing the / Kr gas ratio or the Ar / Xe gas ratio, so that even if the film formation time becomes long and the ratio fluctuates, it is easy to control. it can. Therefore, the target can be sufficiently used to a considerable extent without stopping the film formation.

Further, when the single-wafer type magnetron sputtering apparatus 2 is used, each layer can be continuously formed into a film in the small vacuum chamber 8, but on the other hand, depending on the shape and size of the vacuum chamber 8, the target can be formed. The size will be limited. However, in the present invention, without being restricted by such size limitation, the composition ratio of the layer can be adjusted as required by adjusting the ratio of the sputtering gas. Moreover, according to the manufacturing method of the present invention,
There is also an advantage that the amorphous magnetic layer 5 having excellent corrosion resistance can be obtained.

[0018]

【Example】

(Example 1) Using the single-wafer type magnetron sputtering device 2, a sialon sintered body is used as the target 10 for the dielectric layer 4, and Tb is used as the target 11 for the amorphous magnetic layer 5.
An alloy of _0.30 Fe _0.65 Co _0.05, a sialon sintered body as a target 12 for the dielectric layer 6, and an Al metal as a target 13 for the reflective layer 7 were used. Then, Ar gas at a total flow rate of 100 to 50 sccm, Kr gas at a flow rate of 0 to 50 sccm, and a gas pressure of 0.6 Pa are sputtered on the respective targets from the four inlets 14. As a result, a dielectric layer 4 having a film thickness of 800 Å, an amorphous magnetic layer 5 having a film thickness of 200 Å, a dielectric layer 6 having a film thickness of 200 Å, and a film thickness of 6 are sequentially formed on the polycarbonate substrate 3.
A magneto-optical recording medium 1 in which a 00Å reflecting layer 7 was laminated was obtained.

Next, in manufacturing such a magneto-optical recording medium 1, the flow rates of Ar gas and Kr gas are changed so that the respective content ratios of Fe and Co, the respective content ratios of Ar and Kr, and the coercive force Hc. Was measured, and the results shown in Table 1 were obtained.

For these measurements, the content was measured by ICP emission analysis and the coercive force was measured by a Kerr effect measuring machine.

[0021]

[Table 1]

Then, among the results shown in Table 1, when the Ar content is plotted on the abscissa and the coercive force Hc and the FeCo content are plotted on the ordinate, a graph as shown in FIG. 3 was obtained.

As is clear from the results shown in Table 1 and FIG. 3, it can be seen that the FeCo content can be reduced by decreasing the Ar flow rate (increasing the Kr flow rate.

When the flow rates of Ar gas and Kr gas were changed and the target integration time was also changed, the content ratios of Ar and Co and the coercive force Hc shown in Table 2 were obtained. In addition, when Table 2 is represented graphically, the results shown in FIG. 5 were obtained. By the way, A as a reference example
FIG. 4 shows the relationship between the target integration time and the coercive force Hc when the flow rate of r gas is 100 sccm.

[0025]

[Table 2]

As is clear from the results shown in Table 2 and FIG. 5, the Ar flow rate and the K
The coercive force Hc can be maintained and controlled to be constant by appropriately changing the flow rate of r (thus, by changing the content ratios of Ar and Kr contained in the film over time, the constant coercive force Hc can be obtained. Can be obtained).

In addition, when only Ar gas is used and when Ar gas is used
C / due to an external magnetic field when using gas and Kr gas
When the absolute value of the rising of the N value (external magnetic field value) was measured, the results shown in FIG. 6 were obtained. According to the figure, it is understood that the external magnetic field value can be reduced by adding Kr gas to Ar gas.

Next, when the magneto-optical recording medium 1 of this example was subjected to a corrosion resistance test, the results shown in Table 3 were obtained. According to this corrosion resistance test, when only Ar gas was used, Ar gas (flow rate 60 sccm) and K
With r gas (flow rate 60 sccm), with Ar gas (flow rate 50 sccm) and with Kr gas (flow rate 50 sccm), there were three types of constant temperature and humidity for each magneto-optical recording medium produced. The test was conducted in a tank under the conditions of 80 ° C. and a humidity of 90%.

In the table, ◯ indicates the case where a good result was obtained in the corrosion resistance test, and X indicates the case where it was judged as defective.

[0030]

[Table 3]

As is clear from the results shown in Table 3, 2 of the present invention
The magneto-optical recording medium 1 of the type did not corrode after 4000 hours. On the other hand, in the comparative example, 400
Corrosion becomes remarkable after 0 hours, and the magneto-optical recording medium 1
The inclusion of Kr atoms as well as Ar atoms also has the advantage of improving corrosion resistance.

In the above-mentioned experiment, a mixed gas of Ar gas and Kr gas was used, but instead of this, Ar gas and X gas were used.
Table 4 shows an example in which a mixed gas with e gas is used.

[0033]

[Table 4]

As is clear from the results shown in the table, when Xe gas is used, the Fe content is reduced as in the case where Kr gas is used, whereby the coercive force Hc can be adjusted.

[0035]

As described above, according to the production method of the present invention, A
The composition ratio of the layer can be adjusted simply by changing the r / Kr gas ratio or the Ar / Xe gas ratio, which eliminates the conventional target replacement, which shortens the manufacturing time and reduces the manufacturing cost. As a result, a low-cost magneto-optical recording medium can be provided.

Further, in the manufacturing method of the present invention, even if a single-wafer type magnetron sputtering apparatus is used, a layer having a composition ratio adjusted as required can be formed into a film by simply adjusting the sputtering gas ratio. .

Furthermore, by the manufacturing method of the present invention, excellent corrosion resistance can be achieved, and since a layer having a composition ratio adjusted as required can be easily formed into a film, there is no variation between individual products, and further the products can be manufactured. It is possible to provide a long-life and highly reliable magneto-optical recording medium in which uniform performance can be obtained even within the film surface.

[Brief description of drawings]

FIG. 1 is a sectional view showing a layer structure of a magneto-optical recording element of an example.

FIG. 2 is a schematic configuration diagram of a single-wafer type magnetron sputtering apparatus.

FIG. 3 is a diagram showing the relationship between Ar content and FeCo content or coercive force.

FIG. 4 is a diagram showing a relationship between target integration time and coercive force.

[Fig. 5] Target integration time and coercive force or Ar / K
It is a diagram which shows the relationship with r content rate.

FIG. 6 is a diagram showing a relationship between an external magnetic field and C / N.

[Description of Reference Signs] 1 Magneto-optical recording medium 2 Single-wafer type magnetron sputtering device 3 Substrate 4, 6 Dielectric layer 5 Amorphous magnetic layer 7 Reflective layer 8 Vacuum chamber 9 Substrate support 10, 11, 12, 13 Target 14 Entrance

Claims (2)

[Claims] 1. An amorphous target is formed on a substrate by sputtering an alloy target made of a rare earth metal and a transition metal of Fe and Co with a mixed gas of Ar gas and Kr gas or a mixed gas of Ar gas and Xe gas. A method of manufacturing a magneto-optical recording medium, characterized in that a layer is formed by film formation. 2. The method for producing a magneto-optical recording medium according to claim 1, wherein the amorphous magnetic layer is formed into a film by using a single-wafer type magnetron sputtering device.