JP3086513B2 - Method for manufacturing magneto-optical storage element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a Maku構 relates to a method of manufacturing a magneto-optical storage device capable of perpendicular magnetic recording, in particular, which can shorten the film formation time required by a sputtering method
The present invention relates to a method for manufacturing a magneto-optical storage element having a structure .

[0002]

2. Description of the Related Art In response to a demand for high-density recording, which is particularly increasing in the fields of data files and external memories of computers, magneto-optical storage elements capable of perpendicular magnetic recording such as so-called magneto-optical disks have been developed. I have.

An amorphous alloy thin film of a rare earth metal (RE) and a transition metal (TM) has characteristics such as high recording sensitivity, no grain boundary noise, and easy film formation. Promising as a recording medium.

FIG. 4 shows an example of the film structure of a magneto-optical disk at a practical level (Journal of the Japan Society of Applied Magnetics, Vol. 8,
No. 2, 1984, p. 93). The magneto-optical disk 50 is, for example,
PC (polycarbonate) substrate 51 / first AlN 52 (1
00 nm) / GdTbFe53 (35 nm) / second AlN54
(21 nm) / Al55 (40 nm).

The first AlN 52 has a function of protecting GdTbFe53 and a function as an antireflection film for reducing the reflectance of GdTbFe53. Al55 is a reflection film, and the second AlN54 has a function of increasing the reflectance of Al55. Such a multilayer film structure can increase the small Kerr rotation angle to an effective level by using the RE-TM amorphous alloy thin film alone by the enhancement effect by multiple reflection.

[0006] Each film thickness has an optimum range.
The thickness of the first AlN 52 is selected in the range of 80 to 110 nm, and the thickness of the second AlN 54 is selected in the range of 20 to 40 nm.

[0007] These films are produced using a sputtering method. Each film formation rate is the slowest for AlN and 40 nm.
/ Min, GdTbFe and Al are both 100 nm / min. For example, each time required to form a film with the above-mentioned film thickness is 2.5 minutes for the first AlN 52 and 0.5 minutes for the GdTbFe 53.
35 minutes, second AlN 54 0.525 minutes, Al 55 0.4
It takes a minute, and the whole takes 3.775 minutes.

As an apparatus for mass production in a film forming process of a magneto-optical disk, an in-line sputtering apparatus as schematically shown in FIG. 5 is used. In this apparatus, a preliminary chamber 35 for performing rough evacuation, a first AlN sputtering chamber 36, a G
dTbFe sputtering chamber 37, second AlN sputtering chamber 3
8 and an Al sputtering chamber 39 are sequentially provided.
Between 6 and 39, a buffer chamber 34 for making each sputtering process independent is provided.

In the film forming process, a plurality of disk-shaped PC boards 33 mounted on a tray 32 are placed in each of the chambers 35 to 3.
9, and discharges the targets in the respective chambers 36 to 39 one after another.

Therefore, in the case of the magneto-optical disk 50 having the above-mentioned film structure, the film formation time of the first AlN 52 determines the time of the whole film formation process, in other words, the productivity.

[0011]

However, as described above, the film formation time of the first AlN 52 is much slower than the film formation time of the other films 53 to 55. Therefore, the first AlN5
No. 2 prevents mass production of the magneto-optical disk 50 at a higher speed.

As a solution to this problem, it is conceivable to replace the AlN film with a transparent dielectric film having a high sputtering rate. However, a transparent dielectric material generally has a low sputtering rate and is only about the same as AlN.

On the other hand, as a transparent film having a high sputtering rate, there is conductive tin oxide. However, since tin oxide is an oxide, oxygen is released when an RE-TM amorphous alloy thin film is formed on tin oxide. Since the released oxygen enters the RE-TM amorphous alloy thin film, the rare earth metal is selectively oxidized, thereby deteriorating the magnetic properties of the RE-TM amorphous alloy thin film. For example, the above-mentioned known materials include Si
As a result of an environmental resistance test in which the medium using the O ₂ film was left at 80 ° C. for a long time in the atmosphere, it was reported that the perpendicular magnetization had finally disappeared.

As described above, the magneto-optical storage element in which AlN is simply replaced with tin oxide cannot maintain the reliability as a recording medium for a long time.

[0015]

[Means for Solving the Problems] In order to solve the above-mentioned problems
The invention according to claim 1 includes a plurality of sputtering chambers.
On a transparent substrate using an in-line sputtering device
A first transparent dielectric film, a perpendicular magnetization film, a second transparent dielectric
-Optical storage element in which a film and a reflective film are formed in this order
Manufacturing method, wherein the transparent substrate and the first transparent dielectric
Between the first transparent dielectric film and the body film.
Magneto-optical storage characterized by forming a large transparent film
This is a method for manufacturing an element.

[0016] The invention according to claim 2 is the same as the above claim.
2. The method for manufacturing a magneto-optical storage element according to item 1,
1 A transparent film having a higher sputtering rate than the transparent dielectric film
Magneto-optics characterized by forming a film in a sputtering chamber
This is a method for manufacturing a storage element.

[0017]

[0018]

According to the first aspect of the present invention, the transparent substrate and the first transparent
Sputtering rate between the first transparent dielectric film and the dielectric film
Since a large transparent film is formed, protecting the perpendicular magnetization film
The first transparent dielectric which reduces the reflectance of the perpendicular magnetization film
Thin the first transparent dielectric film without impairing the function of the film
The first transparent dielectric film deposition site.
The required time is reduced, and the transparent substrate and the first transparent dielectric
The transparent film formed between the body film and the
Thus, the time required for forming the transparent film can be reduced. That is,
It is possible to shorten the film formation time of each film in each sputtering chamber
Time required for the entire deposition process.
It can be greatly reduced .

Further, according to the second aspect of the present invention, the first transparent member is provided.
A transparent film with a higher sputtering rate than the dielectric film
Since the film is formed in the sputtering chamber,
The film formation time can be further reduced
Therefore, the time required for the entire film forming process can be further reduced .

[0020]

[0021]

[0022]

[0023]

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, the magneto-optical disk 10
Is, for example, a PC (polycarbonate) substrate 11 /
Layer tin oxide 12 (900 °) / first layer AlN13 (10 nm) / G
dTbFe14 (35 nm) / second layer AlN15 (10 nm) /
The second layer has a multilayer structure of tin oxide 16 (11 nm) / Al17 (40 nm). First layer tin oxide 12 and second layer
The layer tin oxide 16 is a transparent conductive film, and GdTbFe14
Is an amorphous magnetic film.

Each of the films 12 to 17 is sequentially formed by an in-line sputtering apparatus described later as schematically shown in FIG. The individual film formation rate is the slowest for AlN at 40 nm / min, and 100 nm / min for GdTbFe, tin oxide and Al. Therefore, GdTbFe1
The antireflection film of No. 4 and the reflectivity enhancement film of Al17 are not composed of a single layer of AlN as in the prior art, but are composed of two layers of tin oxide and AlN, so that a part of the conventional AlN film is sputtered. Since it is replaced with tin oxide having a high rate, the time required for forming the magneto-optical disk 10 can be reduced.

First layer AlN13 and second layer AlN15
The reason for setting the film thickness to 10 nm is that the depth at which oxygen released from the oxide at the time of sputtering is taken in the films before and after is approximately 3 to 5 nm. Therefore, if the thickness of the AlN layer is set to 10 nm in consideration of safety, free oxygen enters GdTbFe14 and GdTbFe14
The danger of oxidizing bFe14 is eliminated.

As a result of the above film structure, for example, the individual required time for forming the film with the above film thickness is 0.9 minutes for the first layer tin oxide 12 and 0.225 minutes for the first layer AlN13. , GdT
bFe14 was 0.35 min, and the second layer AlN15 was 0.225.
And the second layer tin oxide 16 requires 0.11 minutes and Al17 requires 0.4 minutes. The total time is 2.21 minutes. It is greatly shortened to 3.7 75 minutes.

As described above, the in-line sputtering apparatus shown in FIG. 2 is used as a mass production apparatus in the film forming process of the magneto-optical disk 10. In this apparatus, in a vacuum chamber 21, from a line upstream, a preliminary chamber 25 for performing rough evacuation, a first-layer tin oxide sputtering chamber 22a, a first-layer AlN sputtering chamber 26, and a GdTbFe sputtering chamber 2
7, a second layer AlN sputtering chamber 28, a second layer tin oxide sputtering chamber 22b, and an Al sputtering chamber 29 are sequentially provided.

A buffer chamber 24 is provided between the sputtering chambers to make each sputtering process independent.
The first layer tin oxide sputtering chamber 22 is sandwiched between the buffer chamber 24 and the first layer tin oxide sputtering chamber 22.
a is provided in two rooms. Thus, seven targets are used in the film forming process of this embodiment.

In the film forming process, a plurality of disk-shaped PC boards 23 mounted on the tray 20 are sequentially sent from the preliminary chamber 25 to each sputtering chamber, and the targets in each sputtering chamber are discharged one after another. The entire film forming process of the present embodiment is limited by the film forming process of the first layer tin oxide 12, which takes the longest time for film forming. Therefore, the power supplied to the target of another film forming process is reduced in accordance with the film forming time of the first layer tin oxide 12, and adjustment is made so that the passage times of the tray 20 in each sputtering chamber are equal.

In this embodiment, as described above, the two first-layer tin oxide sputtering chambers 22a are provided, so that the passage time of the tray 20 in each sputtering chamber is one time of the first-layer tin oxide.
Equivalent to the time required for film formation per chamber, 0.9 minutes / 2 = 0.
Can be set to 45 minutes.

On the other hand, if the film structure of the magneto-optical disk 10 is temporarily changed to a PC substrate / first AlN (100 nm) / GdTbF
In the case of e (35 nm) / second AlN (21 nm) / Al (40 nm), by forming three sputtering chambers for the first AlN, the film formation process can be configured with seven targets in the same manner as described above. it can. However, a 100 nm thick first AlN
It takes 2.5 minutes to form a film, so tray 2
The passing time of 0 is 0.84 minutes (≒ 2.5 minutes ÷ 3), which is the time required for forming the first AlN per chamber.

As described above, the magneto-optical disk 10 having the film structure according to the present invention can greatly reduce the time required for the film forming process.

Next, as shown in FIG. 3, the second layer tin oxide 16 can be omitted from the film structure of FIG. In this case, it is necessary to slightly change each film thickness.
By omitting the second layer tin oxide sputtering chamber 22b in the film forming process while setting the film thickness of the film 15 to an optimum value, it is possible to further shorten the time required for the entire film forming process.

[0036]

According to the first aspect of the present invention, a plurality of sputtering
Using an in-line sputtering device with a chamber,
First transparent dielectric film, perpendicular magnetization film, second transparent film
Magneto-optical recording in which a dielectric film and a reflective film are formed in this order
A method for manufacturing a storage element, comprising: the transparent substrate and the first transparent substrate.
Between the first transparent dielectric film and the transparent dielectric film.
This is to form a transparent film having a large data rate .

Therefore, it is possible to protect the perpendicular magnetization film.
Of the first transparent dielectric film for reducing the reflectance of the perpendicular magnetization film
The thickness of the first transparent dielectric film can be reduced without impairing the function.
When the first transparent dielectric film is required
The distance between the transparent substrate and the first transparent dielectric is reduced.
The transparent film formed between the body film and the
Thus, the time required for forming the transparent film can be reduced. That is,
To reduce the film forming time in each sputtering chamber
Therefore , the time required for the entire film forming process can be significantly reduced.

Further, the invention according to claim 2 is the same as the above claim.
2. The method for manufacturing a magneto-optical storage element according to item 1,
1 A transparent film having a higher sputtering rate than the transparent dielectric film
The film is formed in a sputtering chamber .

Therefore, the composition per sputtering chamber is
The film time can be further reduced,
There is an effect that the time required for the entire process can be further reduced.

[0040]

[0041]

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a film structure of a magneto-optical storage element according to the present invention.

FIG. 2 is an explanatory view schematically showing an in-line sputtering apparatus used for a film forming process of a magneto-optical storage element.

FIG. 3 is a longitudinal sectional view showing another film structure of the magneto-optical storage element according to the present invention.

FIG. 4 is a longitudinal sectional view showing a film structure of a conventional magneto-optical storage element.

FIG. 5 is an explanatory view schematically showing an in-line sputtering apparatus used in a conventional film forming process for a magneto-optical storage element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Magneto-optical disk (magneto-optical storage element) 11 Polycarbonate substrate (transparent substrate) 12 First layer tin oxide (transparent conductive film) 13 First layer AlN (first transparent dielectric film) 14 GdTbFe (perpendicular magnetization film and rare earth element) Transition metal amorphous alloy film) 15 second layer AlN (second transparent dielectric film) 17 Al (reflective film)

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-222454 (JP, A) JP-A-61-22456 (JP, A) JP-A-62-192949 (JP, A)

Claims (2)

(57) [Claims] 1. An inline machine having a plurality of sputtering chambers.
This is a method for manufacturing a magneto-optical memory element in which a first transparent dielectric film, a perpendicular magnetization film, a second transparent dielectric film, and a reflection film are formed in this order on a transparent substrate using a sputtering device. Between the transparent substrate and the first transparent dielectric film.
A transparent film having a higher sputtering rate than the first transparent dielectric film is formed.
A method for manufacturing a magneto-optical storage element, comprising forming a film . 2. The magneto-optical storage device according to claim 1,
In the manufacturing method, sputtering is performed from the first transparent dielectric film.
Of transparent film with high efficiency in multiple sputtering chambers
A method for manufacturing a magneto-optical storage element, comprising: