JPS60155668A - Formation of protective hydrocarbon film on surface of magnetic storage medium - Google Patents

Abstract

PURPOSE:To form a protective hard hydrocarbon film having a low coefft. of friction and superior wear resistance on the surface of a magnetic storage medium by carrying out sputtering using a carbon target in an atmosphere contg. a specified gaseous hydrocarbon. CONSTITUTION:A protective hard hydrocarbon film is formed on the surface of a magnetic storage medium by carrying out sputtering using a carbon target in an atmosphere contg. one or more kinds of gaseous hydrocarbons such as CH4, C2H4, C2H6, C3H8 and C6H6. The hard hydrocarbon of the film contains a large number of C-H bonds, and the film has a low coefft. of kinematic friction, small internal stress and high adhesive strength. The film shows superior wear resistance without using a lubricant.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of forming a hydrocarbon protective film on the surface of a magnetic storage medium, and particularly to a method of forming a hydrocarbon protective film on the surface of a magnetic storage medium such as a magnetic drum or magnetic disk used for recording, recording, computers, etc. by sputtering. The present invention relates to a method of forming a hydrocarbon protective film.

In recent years, in order to improve recording density, methods have been proposed in which a ferromagnetic metal thin film made of iron, cobalt, nickel, or an alloy thereof is formed on a substrate by methods such as vacuum evaporation, sputtering, and plating. However, although the thin-film metal magnetic storage media produced by these methods have excellent high-density recording properties, for example, when used in a recording/reproducing device, magnetic recording-p1. Since the medium and the magnetic head are in physical contact and run at high speed, there is a problem in wear resistance due to long-term use.

In order to improve these problems, Sto 2 is added to the surface of the magnetic layer.
, SLB N4 , C%A! , o, etc. are known, but although these protective films are hard, they have a large coefficient of friction and can cause wear or damage to either the protective film or the magnetic head. Furthermore, the method of using these protective films and lubricants in combination has the disadvantage that new problems such as gloss and head stick tend to occur.

The present invention is aimed at improving these drawbacks, and uses an excellent magnetic recording material 4, Natsume, etc., which is selected from specific hydrocarbons and has fewer problems, as a protective film for magnetic storage media. The present invention aims to provide a magnetic recording medium 4t from which a medium can be obtained and a method for forming a hydrocarbon protective film on the surface of the medium.

That is, the present invention provides a method for forming a hydrocarbon protective film on the surface of a magnetic recording medium using CH41
,C! It is characterized by sputtering using carbon as a target in an atmosphere of one or more gases selected from hydrocarbons such as H<, C2H6, C3H@, and CaHa (benzene).

The present invention will be further explained in detail below.

The present invention is a method of forming a hydrocarbon film on the surface of a magnetic recording medium by sputtering using carbon as a target, but the hydrocarbons used as the atmosphere of the present invention are 0M4, C, H, \C2HB s. C2H8・C
Hydrocarbons such as 2H4 and ffcaHa may be used as long as they contain one or more of these gases, or only these gases, but argon (Ar), helium (
There is no problem in using gases such as He) and hydrogen (H2) together.

In the present invention, when carbon is used as a target and sputtering is performed in a gas atmosphere containing one or more selected from the above hydrocarbons as an atmospheric gas, a hard hydrocarbon film containing a large amount of C-H bonds is formed. Ru. The protective film thus obtained has a small coefficient of dynamic friction and low internal stress, so it has strong adhesion. In the conventional sputtering method using carbon as a target, a gas such as Ar % He is used alone as the atmospheric gas, so a hard carbon protective film is formed, but this protective film contains C-H bonds or hydrogen atoms. This is because the internal stress is large, and the adhesion force is weak, and the coefficient of dynamic friction is also large, which is undesirable.

In addition to the above-mentioned atmospheric gas, the conditions for forming the protective film on the magnetic recorder and medium include gas pressure, sputtering power source, mose voltage, and reaction time.

Since these conditions vary depending on the shape and size of the device, they cannot be particularly limited, but any known conditions can be used.

Although it is not necessary to apply a voltage to the magnetic storage medium to which the hydrocarbon film is to be applied in the sputtering process of the present invention, it is also possible to apply a voltage.

EXAMPLES The present invention will be explained in more detail below with reference to Examples.

Example 1 Production of a plated disk After non-magnetic Ni-P was electrolessly plated to a thickness of 50 μm on a mirror-polished aluminum plate with a diameter of 9 crn and a thickness of 2 m,
Mirror polishing was performed to a thickness of 30 μm, and the plating solution shown in Table 1 was used on top of the mirror polishing, and the plating conditions were Co-N1-P (
A magnetic film of Co: 809b-Nt: xi5n, P: 5%) was electrolessly plated (hereinafter referred to as plating disk A) at a liquid temperature of 75° C. to a thickness of 0.1 μm.

In addition, during the pretreatment for electroless plating, Nippon Kanigen Co., Ltd. 1's product name "Suma Sensitizer" and product name "Suma Activator" were used.

Using a sputtering device (product name 1'-CF8-8ESJ) and high-density carbon (product name "HcB-18J") manufactured by Hitachi Chemical Co., Ltd. as a target, sputtering was performed under the conditions shown in Table 2. A hydrocarbon protective film was formed on the surface of plated disk A to a thickness of 80 OA.For comparison, sputtering was performed under the conditions shown in Table 2 (Experiment N18), and a carbon film of 80 OA thick was formed on the surface of plated disk A.
It was formed to have a thickness of 0OA.

Table 3 The physical properties shown in Table 3 were measured by the following methods.

1) Dynamic friction coefficient measurement The measurement was carried out using the rotating device shown in FIG.

Head: 2■φ sapphire ball.

Head load: 5II Relative speed: 5 towns false.

2) Measurement of the number of sliding movements The number of sliding movements until the protective film was destroyed was measured using the apparatus shown in FIG.

Head = 2-tone φ Zafire ball.

Head load: 10 p Relative speed K: 10 m/aec 3) C8S (Contact Start Stop) Test Using a fixed disk drive device, the number of cycles until head crash occurred was measured.

Head: IBM-3350 type, Head load: 9.8g.

Rotation speed: 3600r, I), m, 1 ON-OFF 30 second cycle.

Example 2 A hydrocarbon film with a thickness of 1 μm was obtained on a silicon wafer with a thickness of 0.5 tn under the same conditions as in the experiment Nal except that the reaction time was 75 minutes.

FIG. 2 shows the results of transmission infrared spectroscopic analysis of the silicon wafer coated with this hydrocarbon film.

As shown in Figure 2, 2870, 2920°2960.1
420 and 1375 cW1'' absorption clearly confirmed the presence of C--H bonds in this hydrocarbon film.

Comparative Examples 0 and 5 A carbon film with a thickness of 1 μm was obtained on a 1 μm thick silicone film under the same conditions as in Experiment N[L8, except that the reaction time was 87.5 minutes.

FIG. 3 shows the results of transmission infrared spectroscopic analysis of the silicon wafer coated with this carbon film. According to FIG. 3, no C--H bond was observed in this carbon film.

[Brief explanation of drawings]

The drawings show devices used in Examples and Comparative Examples of the present invention; FIG. 1 is an explanatory diagram of the dynamic friction coefficient and sliding number measuring device, and FIGS. 2 and 3 are examples of Example 2 and Comparative Example, respectively. FIG. 2 is a diagram showing the relationship between wave number and transmittance of a protective film on a silicon wafer prepared by way of example. Number 1... Magnetic storage medium 2... Holder 3... Sapphire bulb 4... Leaf spring 5... Strain gauge 6... XY stage 7... Motor 8... Frame patent application People Denki Kagaku Kogyo Co., Ltd. Tofu [,:1 Figure 3:, [Autumn-1]

Claims (1)

[Claims] A method for forming a hydrocarbon protective film on the surface of a magnetic storage medium, the method comprising using CH as a target for sputtering when forming the hydrocarbon protective film on the surface of the magnetic storage medium by sputtering.