JPH01162256A - Production of magneto-optical recording medium - Google Patents

Abstract

PURPOSE:To continuously form recording layers alternately laminated with RE layers and TM layers at a high speed by continuously carrying alternately disposed RE targets and TM targets and a substrate disposed opposite to the targets. CONSTITUTION:The RE targets 8 consisting of Tb, Gd, or Sm, etc., and the TM targets 9 consisting of Fe, Co, Ni or alloys, etc. of said metals are arrayed alternately at nearly equal intervals to face the substrate 4 in a sputtering chamber 7. Specified bias electric power is simultaneously impressed from power supplies 10, 11 respectively to the RE targets 8 and the TM targets 8. The sputtered particles of the RE metals and TM metals driven out by the plasma particles of Ar generated near the surfaces of the respective targets are released and arrive successively and continuously at the substrate 4 by which the films are formed on the substrate. The recording layers laminated alternately by as much as the number of the RE targets 8 and the TM targets 9 are thereby formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing a magneto-optical recording medium, and more particularly to a method for manufacturing a magneto-optical recording medium in which a multilayer structure is continuously formed by sputtering.

[Prior art]

In recent years, magneto-optical recording media have been widely used for large-capacity data files as magneto-optical disks that can be written and read using laser light.

This magneto-optical recording medium is a multi-layered material in which an electric shield layer, a recording layer, a protective layer, an adhesive layer, etc. are laminated on a transparent substrate such as glass or plastic using the R-Tap method to a thickness of several 1OA to several 200 mm each. It has layers of structure.

The recording layer exhibiting the magneto-optical effect contains a rare earth metal (hereinafter referred to as R
A single layer of an alloy of an alloy of E gold metal (hereinafter referred to as TM gold metal) and a transition metal (hereinafter referred to as TM gold metal), or a layer consisting of the RE gold metal (hereinafter referred to as RE layer) and a layer consisting of the TM gold metal (hereinafter referred to as TM layer). (referred to as λ) or more laminated layers are used. In particular, a record in which the latter QRE layer and TM layer are alternately laminated.
The layer has the advantage that it has excellent magnetization, coercive force, and magneto-optical effect (Kerr effect), and its properties are easy to control. The manufacturing method involves fixing the substrate on a rotating holder and rotating the holder over a rare earth metal target (hereinafter referred to as RE metal target) and a transition metal target (hereinafter referred to as TM metal target). A method of laminating at least 21 thin layers of the RE layer and the TM layer by passing the substrate through the substrate (referred to as a dual simultaneous sputtering method, disclosed in Japanese Patent Application Laid-Open No. 2003-211022).
72 Hiroshi 7, JP 62-21S4J, JP 6 Koko 7Aj, JP 1987-1-i0r/
2, Japanese Patent Application Laid-open No. 62-7104c/, and Japanese Patent Application Laid-Open No. 62-1377!3). A method is disclosed for stacking layers of the RE Gold Metal TM with different gold metal composition ratios by facing the gold metal TM gold metal alloy target and the substrate and changing the bias power applied therebetween over time. There is.

[Problem that the invention seeks to solve]

However, in the dual simultaneous sputtering method, a limited number of substrates are usually set on a substrate holder having a rotating mechanism, and the laminated recording layer is formed only in units of that number. There was a problem in the mass production of magneto-optical recording media. Also, the above-mentioned Unexamined Patent Publication No. 1.2-1
The method of changing the bias power over time as in Japanese Patent No. 3773 can increase the film formation rate, but the RE layer and T
It was not possible to laminate the layer while clearly distinguishing it from the M layer, and the properties were not sufficiently improved. Furthermore, a complicated control mechanism was required to change the bias power in short periods.

The present invention has been made to solve these problems, and provides a magneto-optical recording medium in which a recording layer in which at least two RE layers and TM layers are alternately laminated is formed continuously and at high speed. The purpose is to provide a manufacturing method.

[Structure of the invention]

Such an object of the present invention is to provide a method for manufacturing a magneto-optical recording medium in which the RE layer and the TM layer are laminated on a substrate by sputtering, in which the substrate is continuously deposited at a constant speed in a sputtering chamber maintained at a predetermined degree of vacuum. An RE metal target and a TM metal target are arranged to face each other at a predetermined distance from the nuclear substrate along the transfer path of the substrate while being transferred in one direction, and are arranged so as not to overlap with each other in the transfer direction of the substrate. This is accomplished by simultaneously and successively performing sputtering to deposit each of the metal layers on the base. Particularly, the purpose of the present invention is to prevent the mixing of gold dust particles of both metal targets emitted by simultaneous continuous sputtering of both metal targets by a partition plate provided at the boundary between the RE metal target and the TM metal target. is achieved more effectively.

One embodiment of the present invention will be explained in more detail with reference to the accompanying drawings.

FIG. 1 shows the R
FIG. 2 is a plan view of an apparatus for laminating an E layer and a TM layer by sputtering, and FIG. 2 is a side view thereof.

A transparent substrate made of glass, plastic, etc. is fixed to the side surface of the substrate holder 3, which is mounted almost perpendicularly on the conveyance bell). A plurality of substrate holders 3 are mounted in series at approximately equal intervals on the transport bell, and are used to deposit silicon nitride, silicon oxide, aluminum nitride, zinc sulfide, etc. in a sputtering chamber for forming a dielectric layer. After the dielectric film has been formed, it is sent to the sputtering chamber 7 for forming a recording layer from the direction of the arrow L according to the drive of the transport bell (1).

Inside the sputtering chamber 7, facing the substrate≠,
RE targets such as Tb, Gd or Sm and Fe
, Co, Ni, or alloys of these metals, one or more of each are alternately arranged at approximately equal intervals and at a constant distance from the substrate. The inside of the recording layer deposition chamber 7 is filled with an inert gas such as Ar.
The degree of vacuum is maintained at approximately o''-3 Torr, and the above-mentioned R
Emetat! A constant bias power is simultaneously applied to the RE target power supply 10 and the TM target //, respectively, and the RE gold metal particles ejected by Ar plasma particles generated near the surface of each target are TM gold metal sputtered particles are released,
The recording layers are successively deposited on the substrate μ, and are alternately laminated by the number of RE metals and TM targets.

By disposing a partition plate 12 between the RE metal t and the TM target so as to be substantially orthogonal to each target and the base plate, the RE metal t and the TM target
Mixing of RE gold metal sputter particles and TM gold metal sputter particles emitted from the M target is prevented, and the R
A laminated recording layer in which the E layer and TM layer are clearly separated can be formed.

The thickness and total thickness of the RE layer and TM layer of the laminated recording layer are determined by the conveyance speed of the substrate, sputtering input power, target size, etc., and can be controlled by selecting these factors. Usually, the conveyance speed is from 0, smy minutes to 0,6417 minutes, and the power applied to the target is usually from several 10 W to several toOW.

By making the bias power applied to each target of the RE metalt and each target of the 1M target equal to each other, the thickness of each RE layer and the thickness of each TM layer are made constant, and the thickness of the recording layer is It is possible to make the characteristics uniform across different models.

In order to optimize the magneto-optical effect, the layer thickness of each of the RE layer and TM layer is desirably equal to or more than i.

X or more, and the number of laminated layers is 2 or more in total for the RE layer and TM layer, preferably / 0 or more layers, and the total thickness is
It is desirable that the current is 200A or more.

The RE gold metal for the RE metal is, for example, Gd.
, Tb, Dy% Nd, Sm, or Ho or their alloys, such as Gd! OTb! 0 is used.

On the other hand, the TM gold metal for the TM metal is Fe.
, Co or Ni, or their alloys, such as Fel! Colt etc. are used. In order to improve the corrosion resistance of the TM layer, KPt, Ti, and C are added in the 1M metal.
It may be added in an amount equal to or less than r or Culkj%.

The purity of each of these target metals is at least Tata%.
Desirably, the tatami is 5 or more.

The RE gold metal and TM released from the RE metal and the 1M target by simultaneous and continuous separating
Since the partition plate /2 provided to prevent gold metal particles from mixing is exposed to plasma of an inert gas such as Ar, there is a risk that the material may be mixed into the recording layer.
In order to prevent this, the material of the partition plate is R.
It is desirable that the E gold metal is a TM gold metal. By doing so, at least the RE gold metal can be prevented from being mixed with a third metal other than the TM metal.

From the viewpoint of cost, it is desirable to use TM gold metal as the material for the partition plate.

By providing the partition plate 12, the gap between each target can be further reduced, which is advantageous for downsizing the apparatus.

Further, in order to improve the compositional uniformity of each layer of the recording layer, the substrate may be conveyed while being rotated.

Further, the number of targets may be increased in order to increase the number of layers to be laminated, but an increase in the number of targets can be avoided by reciprocating the same path.

[Effects of the present invention]

In the present invention, the RE layer and the TM layer can be alternately stacked by continuously transporting the substrate facing the RE metalts and the 1M target which are arranged alternately, so that the recording layer is continuous. It is advantageous for film formation. Before and after the snottering chamber 7 for forming the recording layer, there are a sputtering chamber for forming the dielectric layer, a snottering chamber for forming the protective layer, and a load chamber, an unloading chamber, and a snotter ring for forming the reflective layer, as necessary. By connecting it to a chamber or the like, the necessary film formation on the substrate can be performed continuously, which is very advantageous in terms of mass production of magneto-optical recording media.

Furthermore, a recording layer in which the RE layer and TM layer are laminated can be obtained without requiring complicated control of inputs to a substrate rotation mechanism and a substrate as in the conventional method.

Furthermore, by providing the partition plate 12 between each target, an alternately laminated recording layer with less RE gold metal TM gold metal mixing can be obtained, and a good magneto-optical recording layer can be obtained.

The effects of the present invention will be explained in more detail with reference to the following examples.

(Example-l) Thickness/, 2wm,! , 2! Silicon nitride (S) with a thickness of roo
A thin film of i3N, ) was provided as a dielectric layer, and a recording layer of alternately laminated RE layers and TM layers was provided thereon in the following manner.

! A total of 7 μ of Tb targets (RE metal) and Fe g 5 CO15 alloy target (TM metal) with a size of inch x r inch were arranged alternately with a gap of about 2 inches. Ta. After reducing the initial vacuum level in the sputtering chamber to 'X'0-6 Torr or less, A
r gas was introduced and the vacuum was maintained at 10 Torr.

Then the power applied to each Tb target is 10OW1 each FerjCo/! Increase the power applied to the alloy target by 12
The power was fixed at 30 W, and a glass substrate with a dielectric layer preliminarily provided thereon was sent at a speed of 0.3 min/min to a distance of 30 m from each target, and a thin layer of Tb and PerICo/7 alloy was deposited on it. A recording layer consisting of an RE layer and a TM layer was provided. After that, analysis using Auger spectroscopy and small-angle X-ray scattering revealed that the Tb layer was 20 to 1 FerICo/! The alloy layer of is λ! A, the total thickness was JelA.

A protective layer of silicon nitride (1OOOA thick) is placed on the recording layer as a protective layer.
A thin film of Si3N4) was formed by sputtering.

As a result of measuring the magnetic properties of the recording layer using a vibrating sample magnetometer and a Kerr hysteresis device, Hc (coercive force) was t jK
Oe or more, θk (Kerr rotation angle) is 0°4co", Tc
(Curie temperature) was irooC.

In addition, at the interface between the Tb layer and the F e B 5 CO5o alloy layer, a layer having a mixture of both compositions was found to be about 6A.

(Example-2) In Example-7, Tb target and FeB.

Feg5C between the Co□5 alloy target.

, 5 partition plates were installed. The closest distance between the board and the partition plate is approximately! Simple.

Other conditions were the same as in Example-7.Tb and FeB5Co
Alternately laminated recording layers of alloy No. 5 were provided. Tb layer is JOA,
The F'e Co alloy layer is 2jX and the total thickness is 3/I
It was A. The boundaries between each layer were compositionally clearer than in Example-I.

After forming a protective layer under the same conditions as in Example 1, the magnetic properties of the recording layer were measured, and Hc was found to be 1! OK'Oe and above,
θ is 0. μl0, Tc was /400C.

(Example 3) In Example 2, the glass substrate was transported in 0.6 m 1 minute and the power applied to the Tb target was 2QOW, Fe
B 5 Co□5 alloy target power t≠
I set it to tOW.

The Tb layer was 'rA, the F e B 5 CO15 alloy layer was 2JX, and the total thickness was 2roX. After forming a protective layer of silicon nitride under the same conditions as in Example 7, the characteristics of the recording layer were measured and found that Hc was /rKOe or more, θ was O1 3°, and Tc was ttr"c. .

[Brief explanation of the drawing]

FIG. 1 is a plan view of the sputtering chamber in the present invention, and FIG. 2 is a side view. 3...Substrate holder μ...Substrate 7...Sputtering chamber r...RE meter...TM meter 12. ...Partition plate patent applicant Fuji Photo Film Co., Ltd.

Claims (2)

[Claims] 1. In a method for manufacturing a magneto-optical recording medium in which a rare earth metal layer and a transition metal layer are laminated on a substrate by sputtering, the substrate is continuously transferred in one direction at a constant speed in a sputtering chamber maintained at a predetermined degree of vacuum. facing the substrate at a predetermined distance along the transfer path of the substrate while
A magneto-optical recording medium characterized in that a rare earth metal target and a transition metal target, which are arranged so as not to overlap with each other in the transport direction of the substrate, are simultaneously and continuously sputtered to laminate each of the metal layers on the substrate. manufacturing method. 2. A magneto-optical device characterized in that a partition plate provided at the boundary between the rare earth metal target and the transition metal target prevents mixing of metal particles of both metal targets emitted by simultaneous and continuous sputtering of both metal targets. A method for manufacturing a recording medium.