JPH0715772U - Substrate holder with heater - Google Patents

Abstract

(57) [Summary] [Object] To provide a thin film magnetic disk substrate holder for stably manufacturing a magnetic disk having high magnetic characteristics and little variation. [Structure] In a holder for an in-line type sputtering apparatus used for manufacturing a thin film magnetic disk, a thin film magnetic disk substrate holder in which a heating device is directly mounted on a substrate holder on which a disk substrate is mounted.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a substrate holder for mounting a disc substrate used in an in-line type sputtering apparatus for manufacturing a thin film magnetic disc.

[0002]

[Prior art]

 In recent years, thin-film magnetic disk devices for computers have been strongly required to have a large capacity, but in order to achieve a large capacity, it is necessary to increase the recording density of a magnetic recording medium. In order to increase the recording density, it is required to increase the coercive force of the magnetic recording medium and the substrate having a smooth surface that enables the flying height of the magnetic head to be reduced. Conventionally, as a substrate for a magnetic recording medium, an aluminum substrate having a Ni—P plating layer with a film thickness of 10 to 20 μm on its surface has been used. The surface of the Ni-P plated layer is subjected to a surface roughening treatment (texture treatment) with a center line average roughness Ra of about 65 Å for the purpose of preventing adsorption to the recording / reproducing magnetic head. In recent years, a material having a smoothness up to about Ra = 40 angstrom has been used, and it is also considered to use a non-magnetic substrate such as glass, ceramics or carbon as a substrate having a further excellent smoothness. A substrate having a thickness of about 0.64 mm to 1.27 mm is used. In general, an in-line type as shown in FIG. 2 is often used as a sputtering apparatus for mass-producing thin film magnetic disks. In this device, as shown in FIG. 3, a disk substrate is mounted on a substrate holder in the atmosphere, heated by a preheating heater and a heating heater, and then a Cr thin film is deposited on the disk substrate by sputtering and then a Co alloy which is a magnetic recording medium. A system thin film is formed, and then a carbon film for the purpose of lubrication is formed.

The purpose of heating the disk substrate before the sputtering film formation is to control the coercive force of the thin film magnetic disk by heating the substrate, and to absorb the adsorbed gas and moisture on the surface of the substrate and the substrate holder that cause coercive force fluctuation. And so on. As the substrate holder, one having a plate thickness of about 6 to 8 mm is usually used, and a surface roughening treatment of Ra = 1 to 4 μm is performed on the surface so that a film attached by sputtering is not peeled off. As a material for the substrate holder, Al alloy or Ti alloy is generally used.

[0004]

[Problems to be solved by the device]

 Due to the recent demand for higher recording density of thin film magnetic disks, a medium coercive force of 1500 [O e] or more has been required. Since the coercive force of the medium improves as the substrate heating temperature increases, the substrate heating temperature is also increasing. However, the temperature difference between the substrate holder and the disc substrate tends to increase accordingly. After heating the disk substrate and the substrate holder, the temperature of the substrate holder drops while being transported to the front of the target for forming the Co alloy thin film and the carbon film, and the heat is taken from the disk substrate to the substrate holder. As a result, the temperature of the disk substrate is lowered, so that sufficient magnetic properties and uniformity of the film cannot be obtained. Further, since the disk substrate is not deformed by heat, it cannot be heated to a high temperature unnecessarily.

[0005]

[Means for Solving the Problems]

 The means taken in the present invention to solve the above-mentioned problem is, for example, to embed a heater wire for heating in a substrate holder on which a disk substrate is mounted, to manufacture a thin film magnetic disk by mounting a substrate holder on which heating means is mounted. Is to use.

[0006]

[Action]

 As in the embodiment of the present invention, a heater wire is attached to the substrate holder and the temperature of the substrate holder is heated and maintained near the substrate temperature to prevent the disk substrate temperature from decreasing. Therefore, since the temperature of the disk substrate is kept uniform and high, a magnetic disk having uniform magnetic characteristics and high magnetic characteristics can be stably manufactured. Further, by mounting the heater, not only the time for heating the disc substrate and the substrate holder is shortened but also it is not necessary to heat the disc substrate to an excessively high temperature, and the thermal deformation of the disc substrate can be prevented.

[0007]

【Example】

 Hereinafter, the present invention will be described in detail with reference to examples. However, the scope of the present invention is not limited by these embodiments. (Embodiment) The shape of the substrate holder according to the present invention is shown in FIG. 1, and the conventional substrate holder used as a comparative example is shown in FIG. The substrate holder of the present invention is made for a 3.5-inch aluminum alloy disc substrate having a plate thickness of 1.27 mm and an outer diameter of 95 mm, and has a built-in heater (Fig. 1). 36 disc substrates were set in the substrate holder in the atmosphere. After that, the substrate holder is sent to the preheating chamber and evacuated, and then vacuum heating is performed at a heating temperature of 290 ° C. for 3 minutes by the first heater, and further the substrate holder is sent to the sputtering chamber which is evacuated to a second vacuum. The heater was used to heat the substrate at a temperature of 290 ° C. for 2 minutes (FIG. 2).

FIG. 4 shows the relationship between the surface-measured temperature and the standing time of the heater-equipped substrate holder of the present invention after heating the second heater and the disk substrate set therein. As shown in FIG. 4, it can be seen that the temperature of the substrate holder and the temperature of the disc substrate are kept at substantially the same temperature, and the temperature drop hardly occurs after leaving for 10 minutes or more. Actually, sputter film formation takes less than 2 minutes after the second heater is heated, but as shown in FIG. 4, such a temperature change in the sputter region does not pose a problem. After the heating of the disk substrate was completed, Ar gas was introduced to maintain the inside of the sputtering chamber at 2.66 Pa, Cr and CoCrTa were sequentially deposited, and all the thin film magnetic disks in the fabricated substrate holder were measured with a BH meter. Then, the coercive force was measured and the average value of the coercive force and the standard deviation of the coercive force variation were obtained. The results are shown in the row of Examples in Table 1.

[0009]

[Table 1]

Comparative Example 36 disc substrates similar to those of the example were set in a conventional commercial aluminum alloy holder (830 mm × 780 mm × 6.5 mmt) shown in FIG. 3 in the atmosphere, and heated under the same heating conditions as the example. I went. FIG. 5 shows the relationship between the substrate holder of the conventional substrate holder after heating the second heater and the disc substrate set therein and the surface measurement temperature. As shown in FIG. 5, the temperature difference between the substrate holder and the disk substrate is large, and it is presumed that the temperature of the disk substrate is large and the heat of the disk substrate is flowing out to the substrate holder even after left for 10 minutes. In addition, the temperature drop of the disk substrate during the sputter region time zone is remarkable, and problems are expected in terms of magnetic properties. Next, after heating of the disk substrate was completed, a film was formed in the same manner as in the example, and the coercive force was measured. The results are shown in the row of the comparative example in Table 1. Table 1 shows that the conventional substrate holder, which is a comparative example, has a low magnetic coercive force in comparison with the examples, and the standard deviation (σ) of the coercive force is large and the variation is large. I understand.

[0011]

[Effect of device]

 According to the present invention, it is possible to heat and heat the substrate holder by attaching a heater to the substrate holder for setting the disc substrate. Therefore, the substrate holder can be used for manufacturing a thin film magnetic disk. During sputter deposition, heat can be prevented from flowing from the disk substrate to the substrate holder, and the temperature of the disk substrate can be prevented from decreasing, making it possible to manufacture thin-film magnetic disks with high coercive force. Further, since the temperature of the substrate holder becomes uniform, the variation in magnetic characteristics of the disk substrate in the substrate holder is reduced, and the yield is improved.

[Brief description of drawings]

FIG. 1 is a schematic view of a heater mounting type substrate holder showing an embodiment of the present invention.

[Fig. 2] Schematic diagram of in-line type sputtering device

FIG. 3 is a schematic view of a conventional substrate holder.

FIG. 4 is a diagram showing a relationship between temperature and time of the disk substrate and the substrate holder when the heater mounting type substrate holder of the present invention is used.

FIG. 5 is a diagram showing a relationship between temperature and time of a disk substrate and a substrate holder when a conventional substrate holder is used.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kohei Ito 5200 Mikajiri, Kumagaya-shi, Saitama Hitachi Metals Co., Ltd. Magnetic Materials Research Institute (72) Masahiro Tobiyo 5200 Mikageri, Kumagaya, Saitama Hitachi Metals Co., Ltd. In-house (72) Hidetoshi Hagiwara, Hidetoshi Hagiwara, 5200 Sankejiri, Kumagaya, Saitama Hitachi Metals Co., Ltd.

Claims (2)

[Scope of utility model registration request] 1. A disk holder for an in-line type sputtering apparatus used for manufacturing a thin film magnetic disk, wherein a heating device is directly mounted on the substrate holder on which the disk substrate is mounted. 2. The thin film magnetic disk substrate holder according to claim 1, wherein the heating device is a heater.