JPS62133605A - Manufacture of insulating film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 〔overview〕 An insulating film, such as a magnetic film in a thin film magnetic head.

When forming an insulating film etc. when stacking coils etc.,
The film forming process is performed in multiple steps, and subsequent to these multiple intermediate film forming steps, a cleaning process for cleaning the intermediate film is added to remove defects that occur during film formation.

[Industrial application field]

The present invention relates to a method for forming an insulating film.

Thin film magnetic head (M
The R head) has writing and reading characteristics that are independent of the relative speed between the head and the medium, so it can be used for low-speed running media and has a wide range of uses.

In a thin film magnetic head, magnetic films, coils, etc. are layered on a substrate using vacuum film forming technology, and an insulating film (hereinafter referred to as a thin film) is provided to insulate these conductive films from each other.

To ensure good read and write characteristics of a thin film magnetic head (hereinafter referred to as the head) and to prevent deterioration of the above head characteristics due to dielectric breakdown of this thin film during operation, a thin film with excellent dielectric strength is formed. It is hoped that [Prior art] Silicon dioxide (STOZ), aluminum oxide (Aj!zo3), etc. are used as thin film materials, and films with a thickness of about 1 μm, for example, have been obtained by a continuous film formation method using sputtering. .

In this conventional method, a sputtering device is operated to form a thin film, and the main focus is on increasing the film thickness without performing any particular processing during the process of forming the thin film.

[Problem that the invention seeks to solve]

In such a conventional thin film formation method, a considerable thickness is required to satisfy the electrical insulation required for a thin film magnetic head. For example, the thickness of this thin film is 1 μm.
m, the gap in the writing and reading sections of the head becomes wide and the electromagnetic conversion characteristics deteriorate.

The reason why the film becomes thick to meet the desired dielectric strength voltage is because foreign matter or dirt gets into the film during the thin film formation process, and if this foreign matter is conductive, it causes an electrical short circuit through the foreign matter. Furthermore, even if the foreign matter is insulating, there is no insulating material for thin film formation in the area where the foreign matter is present, which effectively reduces the thickness of the thin film and often reduces the dielectric strength voltage. .

The present invention has been made in view of the above, and an object of the present invention is to provide a method for forming an 8M film having excellent electrical insulation properties even if the film thickness is small.

[Means for solving problems]

FIG. 1 is a diagram illustrating the principle of the method for forming an insulating film according to the present invention.

Sputtering using the desired material for the base layer.

Forming a thin film using other film forming techniques such as vapor deposition (
Intermediate film formation step Bl).

Next, the surface of the formed thin film is cleaned (cleaning step B).

After this, the intermediate film forming step B3. The cleaning step B2 is performed once.

Steps B and B are repeated until the thickness of the thin film to be formed reaches a desired value.

[For production]

The intermediate film forming step B+ is performed multiple times until the thickness of the thin film to be formed reaches the desired value, and the cleaning step B2 is performed following the intermediate film forming step B1, so that foreign matter and dirt on the surface of the intermediate film are removed. This reduces the amount of foreign matter and dirt in the final thin film, and prevents a drop in dielectric strength caused by these foreign matter and dirt, resulting in an insulating thin film with high dielectric strength even if it is thin. can get.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a diagram for explaining the present invention in detail. The figure shows a sputtering device used in the film forming process, with argon (^r) gas G serving as a plasma generation source in a vacuum chamber B.
5×1O−3 Torr, and a pair of opposing electrodes D1. D2 is provided. A target T is provided at the tip of the electrode D2, a substrate K is provided at the tip of the electrode D2, and a power source P is provided between these electrodes.

A is a hole for introducing and discharging gas G. Electrode.

Since a voltage is applied between D2 by the power source P, a plasma discharge is generated by the gas G, and silicon dioxide flies out from the target T formed of silicon dioxide (Sing) due to this plasma discharge, and the substrate K A silicon dioxide film is formed on the substrate.

The thickness of the Stow film M formed on the substrate can be estimated by measuring the film formation time by sputtering, since the thickness of the film formed per unit time is known once the sputtering conditions are determined. I do.

If the target film thickness value is , then film thickness L+(Lt<Lt
) is obtained by intermediate film forming step B. This intermediate film is cleaned in a cleaning step B2.

Cleaning is performed as follows.

This intermediate film is rinsed with pure water, and then subjected to ultrasonic cleaning in isopropyl alcohol (1 minute cleaning) -> acetone (3 minute cleaning) - isopropyl alcohol (1 minute cleaning).

When the cleaning step B2 is completed, this intermediate film is put into the above-mentioned sputtering apparatus to form a 5iOz film. That is, the process moves to the next intermediate film forming step B1.

This second intermediate film forming step B is continued until the film thickness reaches L2.

Next, the process moves to cleaning step B2.

In this way, the intermediate film forming step B and the cleaning step B2 are repeated until the target film thickness value La is reached.

The film thickness formed in the first intermediate film forming step B1 is
Then, LT=Σt, 1 i=1.

FIG. 3 shows the resistance values of the insulating film when N=1.2.3.4. The figure shows the results of forming a 5i02 film on four manganese zinc ferrite substrates by the method described above and measuring the resistance value thereof.

When N=1, the target film thickness value L7 is obtained in one film forming process, and this corresponds to the conventional thin film forming method described above. LT, = 0.5 μm.

In the case of N=2.3.4, it can be seen from the first intermediate film formation in FIG. 3 that as N increases, the variation in film resistance becomes smaller, and a thin film with a small resistance value is not formed.

In this embodiment, SiO□ was used as the material for forming the insulating film, but the present invention is not limited to this, and is also useful when using an organic material as well as an inorganic material as the film forming material.

〔Effect of the invention〕

As described above, the insulating film forming method according to the present invention performs the intermediate film forming process multiple times, and following these intermediate film forming processes, the cleaning process removes dirt on the surface of the intermediate film formed in the intermediate film forming process. Since the foreign matter is removed, it is possible to prevent the insulation film resistance from decreasing due to dirt and foreign matter.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention, FIG. 2 is a diagram illustrating details of the present invention, and FIG. 3 is a diagram showing intermembrane insulation resistance values. T: Targetft, G: Gas, K: Substrate, M: 5i (
h membrane, D,, Dx: electrode. Figure 3: Inter-chamber membrane formation process number of times Diagram of insulation resistance between membranes

Claims (1)

[Claims] In an insulating film forming method in which an insulating film is formed on a base layer by a film forming step, the film forming step consists of a plurality of intermediate film forming steps B_1, and each intermediate film forming step B_1 includes A method for forming an insulating film, further comprising a step B_2 of cleaning the surface of the intermediate film.