JPH0620321A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve productivity and to save space and manpower by executing a process of successively and continuously forming various kinds of laminated films by sputtering in a single vacuum chamber and using a common gaseous kind. CONSTITUTION:Six sheets of disk substrates 5 are put into a cassette 6 and are sent into a load locking chamber 2 by opening a gate valve 4a. After this load locking chamber 2 is vacuum evacuated, the substrates are set into the loading part of a vacuum chamber 1. One sheet of the disk substrates 1 is taken out of this part and is transferred into a transfer part 13. Disk holders constituted of five pieces are rotated stepwise by 72 deg. each at every cycle time in a direction (b) shown in Fig. The SiN film of the first layer is formed by sputtering in a first process section 9, the TiFeCo film of the second layer in the second process section 10, the Sin film of the third layer in the third process section 11 and the Al film in the fourth process section 12, respectively. After finishing the film formation, the substrates are transferred and housed into the cassette 6 from the transfer part 13 and are taken out to the arm. through an unload locking chamber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a magnetic recording medium, and more particularly to a method for manufacturing a magnetic recording medium composed of a plurality of thin films with high mass productivity.

[0002]

2. Description of the Related Art Magneto-optical recording media are usually formed by sequentially forming a first layer dielectric film, a second layer magnetic recording film, a third layer dielectric film and a fourth layer reflective film on a disk substrate made of plastic or the like by sputtering. It is made by doing. In a mass production sputter manufacturing apparatus for forming such a laminated film, an in-line configuration as shown in FIG.

That is, first, a plurality of disk substrates are attached to a carrier, and then a gate valve (10
6a) is opened and sent to the load lock chamber (101) for vacuuming, and then the vacuum partition gate valve (106b) is opened to set the carrier to the first process chamber (1).
02), the gate valve (106b) is closed to start the supply of sputter gas, and after a predetermined pressure is reached, sputter film formation is performed. Next, after the formation of the first layer film, the gas supply is stopped and the gas is sufficiently exhausted, and then the second process chamber (10
3) The vacuum partition gate valve (106c) and the carrier are sent to the second process chamber (103), the gate valve (106c) is closed, and the second layer film is formed through the same steps as the first process. It is carried out, further sent to the third process chamber, completed the film formation of a plurality of thin films, and finally taken out to the atmosphere through the unload chamber (104).

In this case, the vacuum partition of each process chamber is shown in FIG.
A gate valve is usually used as shown in Fig. 2, and in a sputtering apparatus that deposits one disk at a time, instead of a gate valve, for example, a carrier with an O-ring is pressed into the process chamber by mechanical drive, The method of partitioning the vacuum of the chamber from the transfer chamber is adopted.

As shown in FIGS. 3 (a) and 3 (b), the disk substrate (107) is connected to the gate valve (106).
g) is opened and carried into the load lock chamber (101) and transferred to the disc holder (109).
At this time, the transfer chamber (105) and the load lock chamber (101)
And each process chamber is vacuum sealed and isolated by an O-ring (108). Gate valve (106
After closing g) and exhausting the load lock chamber (101) sufficiently, all disc holders (109) are lowered to the lower part of the transfer chamber (105) as shown in FIG. 3b. Here, it is transferred to a carrier carrier, then this carrier is sent directly below to the next process chamber, transferred to the disc holder at that position, and this holder is pushed up to vacuum seal the process chamber with an O-ring (108). After starting the supply and reaching a predetermined gas pressure, the sputter film formation is carried out. After the film formation is completed, the gas supply is stopped and the gas is sufficiently evacuated, the disc holder (109) is lowered, and the same steps are repeated. It is taken out to the atmosphere through the unload lock chamber (104).

In this case, when only a process which is a series of these steps requires a longer time than other processes, a method of shortening the cycle time and improving the productivity by dividing the process into two or more chambers is also adopted. ing. This transport system is not limited to a linear transport system as shown in FIGS. 2 and 3, but a rectangular transport system in which the loading part and the unloading part of the disk are close to each other is adopted, and a plurality of arms with disk holders are used. Rotate the ring-shaped carrier that holds the book in steps,
A circular transfer system is also employed in which the process is performed by dividing the vacuum between the process chamber and the transfer chamber in each step.

[0007]

However, providing a vacuum partition in each process chamber not only complicates the apparatus configuration, but also mechanically repeats the opening / closing process of the partition for each cycle and the supply / exhaust of sputter gas. The operation sequence of the apparatus becomes complicated due to the repeated steps of the above. Further, since the vacuum partition is mechanically driven, it may cause a device failure during long-term operation. If the disc substrate is exposed to the vacuum of the process chamber and the transfer chamber for a long time during the sputtering process of each thin film layer, the residual gas such as moisture in the vacuum causes the contamination of the film surface to deteriorate the quality of the product. This is one of the causes of a decrease in yield.

[0008]

The present invention relates to a method of manufacturing a magnetic recording medium which solves the above disadvantages and problems, in which a transparent disk substrate is provided with a dielectric film, a magnetic film, a dielectric film, In the manufacturing process of the magneto-optical recording medium in which the metal reflection film is sequentially and continuously formed by sputtering, the process is performed in a single vacuum chamber, and a common gas species is used.

That is, as a result of various studies on the method for producing a magnetic recording medium efficiently and with high productivity, the present inventors found that the dielectric film, the recording film, and the reflective film constituting the magnetic recording medium were all formed. In spite of the fact that the sputtering method is carried out in an inert gas, even though the sputtering conditions are different from each other, they are all based on the sputtering method under vacuum conditions. The inventors have found that common gas species can be used, and conducted research on the supply and exhaust method of this process gas and the sputtering power adjustment method of each process, and completed the present invention. This will be described in more detail below.

[0010]

The present invention relates to a method for manufacturing a magnetic recording medium and the sputtering apparatus. The method for manufacturing a magnetic recording medium comprises a transparent disk substrate on which a dielectric film, a magnetic film, a dielectric film and a metal reflecting film are successively successively formed. In the manufacturing process of the magneto-optical recording medium which is sputter-formed, the process is performed in a single vacuum chamber and a common gas species is used. According to this method, compared with the conventional method. Since the device configuration is greatly simplified, the magnetic recording medium can be efficiently manufactured with a short cycle time and with high productivity.

In the manufacture of the magnetic recording medium according to the present invention, as described above, the manufacturing processes of the dielectric film, the recording film and the reflective film are carried out in a single vacuum chamber, and the same process is carried out using a common gas species such as Ar gas. Is performed using. That is, in the magnetic recording medium, for example, the first dielectric film of the first layer is a SiN film, the recording film of the second layer is a TbFeCo film, and the second dielectric film of the third layer is a SiN film.
When the N film and the reflective film as the fourth layer are Al films, in the conventional method, the second and fourth layers are in Ar gas, and the first and third layers are usually Si targets. The film is formed by a reactive sputtering method in a mixed gas of Ar and N ₂ .

However, if the target is Si ₃ N ₄ during the formation of this SiN film, the film can be formed by the sputtering method in Ar gas.
Since the pressure of the gas is almost the same in all cases, the gas in all the process chambers can be the common Ar gas if the target at the time of forming the SiN film is Si ₃ N _4. Since it is not necessary to make the vacuum of each process chamber independent, it is possible to process with a single vacuum tank of this entire process.

Further, in the conventional method, since each process is not performed with the same gas, in order to prevent cross-contamination of the process gas between the process chambers, complete replacement by exhausting and re-supplying the process gas is performed. However, according to the method of the present invention in which all processes are performed with a common process gas, since there is no such process gas cross-contamination, the exhaust and supply of the process gas are steady. You can

Therefore, according to the present invention, the magnetic recording medium can be manufactured by a method of carrying out a plurality of processes in a single vacuum chamber using a common Ar gas which is constantly supplied and exhausted. Further, in the mass production apparatus, the disk substrate can be sequentially moved to each part where the sputtering process is performed, and the manufacturing can be performed with high productivity.

The point that the film surface of the disk substrate is contaminated by the residual gas in the vacuum during the sputtering process step can be suppressed by shortening the waiting time including the transport time from one sputtering to the next sputtering. . That is, the process time is set for the process that takes the longest time in the whole process, and the other process times are slowed down by intentionally reducing the process power, and adjusted to be almost the same as the process. By shortening the vacuum exposure time of the disk, it is possible to suppress contamination by residual gas.

Next, a method of manufacturing a magnetic recording medium according to the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a top view of a magnetic recording medium manufacturing apparatus according to the present invention. First, six disk substrates 5 are put in a cassette 6, a gate valve 4a is opened and the disk is sent to a load lock chamber 2. After the load lock chamber 2 is evacuated, the load lock chamber 2 is sent to the load section of the vacuum chamber 1, and one disk substrate is taken out from here and transferred to the transfer section 13.

In this case, the disk holder having five structures is step-rotated in the direction of b in the figure by 72 ° for each cycle time, and the first layer SiN film is formed on the first process site 9 by the second process.
The second layer TbFeCo film is formed at the process part 10 and the third process part is formed.
The third layer SiN film is sputter-deposited at 11 and the Al film is sputter-deposited at the fourth process portion 12, and after the film formation is completed, it is transferred from the transfer section 13 to the cassette 6 and transferred to the atmosphere via the unload lock chamber. However, since the vacuum partition repeating step and the process gas supply / exhaust repeating step can be omitted during the cycle time, the advantage that the cycle time can be shortened is given.

[0018]

EXAMPLES Next, examples of the present invention will be given. Example A single crystal silicon wafer having a diameter of 150 mm was used as a substrate for film formation, a Si ₃ N ₄ target was used, and high frequency discharge at 13.56 MHz was performed in Ar in a gas pressure of 5 mTorr for Si.
An N single layer film was formed by sputtering. Further, in the same gas atmosphere, the TbFeCo target was used to form the magnetic layer TbFeCo film by A
A single layer film was formed on each of the reflection film Al film by direct current discharge using a 1 target.

In this case, the distance between the target and the substrate is 60.
Fixed to mm, the sputter power is up to 2.5kw when depositing a SiN film of high frequency (RF) discharge, and 1.5kw when depositing a TbFeCo film.
Up to 3 kw for Al film, and the film thickness of the obtained film was measured with a stylus profilometer. Table 1 shows the target size and the deposition rate per unit power measured with a magnetron sputtering device. The results were as shown.

The sputtering gas pressure is 2 to 10 mT.
Although it was changed in the range of orr, the dependence of the film formation rate on the gas pressure is small, so Table 1 shows the result of 5 mTorr. In Table 1, the SiN film as the third layer is formed by the conventional method. The results are also shown when Si is the target and the gas is Ar + N ₂ .

[0021]

[Table 1]

Then, based on the results of Table 1, since the film formation rate of the Al film as the fourth layer is the slowest among the four layers, the sputtering time is set to 5 seconds, and the sputtering time of the other films is set in vacuum. In order to shorten the waiting time from sputtering to suppress the film surface contamination due to the residual gas, the sputtering power was set to 5 seconds, which was the same as that for the Al film, and the sputtering power was as shown in Table 2. In this case, since the rotation of the disk holder can be performed in 1 second, the cycle time of this apparatus is 6 seconds including the sputtering time of 5 seconds, and high productivity can be realized.

[0023]

[Table 2]

[0024]

As described above, the present invention relates to a method for manufacturing a magnetic recording medium, in which a dielectric film, a magnetic film, a dielectric film and a metal reflection film are successively sputtered on a transparent disk substrate. In the manufacturing process of the magneto-optical recording medium to be formed, the process is carried out in a single vacuum chamber and a common gas species is used. According to this, the device configuration and the operation sequence are simple. Productivity is improved by shortening the cycle time and shortening the cycle time, and in the present invention, since the device is made much more compact than the conventional model, the space saving and the utility of the power system, cooling water, etc. are greatly saved. The advantage of being

[Brief description of drawings]

FIG. 1 is a top view of a magnetic recording medium manufacturing apparatus according to the present invention.

FIG. 2 is a longitudinal sectional view of a magnetic recording medium manufacturing apparatus according to a conventional method.

3A and 3B are vertical cross-sectional views of a magnetic recording medium manufacturing apparatus according to a conventional method.

[Explanation of symbols]

1 ... Vacuum tank 101 ... Load lock chamber 2 ... Load lock chamber 102 ... First process chamber 3 ... Unload lock chamber 103 ... Second process chamber 4 ... Gate valve 104 ... Unload lock chamber 5 ... Disk substrate 105 ... Transfer chamber 6 ... Cassette 106 ... Gate valve 7 ... Disk holder 107 ... Disk substrate 8 ... Target 108 ... O-ring 9 ... First process part 109 ... Disk holder 10 ... Second process part 11 ... Third process part 12 ... Fourth process part 13 ... Transfer part 14 ... Disk holder rotation drive part a ... Transfer direction b ... Rotation direction

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazumi Yamamura, 3-2-1 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa Shin-Etsu Chemical Co., Ltd. Corporate Research Center (72) Inventor, Yoshimasa, Takatsu-ku, Kawasaki-shi, Kanagawa 3-2-1 Sakado, Corporate Research Center, Shin-Etsu Chemical Co., Ltd. (72) Inventor Shin 2-3-1, Sakado, Takatsu-ku, Kawasaki City, Kanagawa Shin-Etsu Chemical Co., Ltd. Corporate Research Center

Claims (3)

[Claims] 1. A transparent disk substrate, a dielectric film, a magnetic film,
In a manufacturing process of a magneto-optical recording medium in which a dielectric film and a metal reflection film are sequentially sputtered, the process is performed in a single vacuum chamber, and a common gas species is used. Manufacturing method. 2. The method of manufacturing a magnetic recording medium according to claim 1, wherein the supply and exhaust of the process gas are continuously and constantly supplied during the manufacture of the recording medium. 3. The method of manufacturing a magnetic recording medium according to claim 1, wherein all the processes are performed at substantially the same common time by adjusting the sputter power of each process.