JPS6025212A - Manufacture of magnetic alloy film - Google Patents

Abstract

PURPOSE:To enable to manufacture a film body having small coercive force according to a simple method by a method wherein the magnetic alloy film is formed on a substrate according to sputtering in the specified high vacuum. CONSTITUTION:When sputtering is performed in the high vacuum of 10<-4>torr or more, coercive force of thus obtained magnetic alloy film is made small as to 0.4Oe or less. For example, gas such as Ar, etc. is introduced into an ion source 1 as to enable to perform sputtering in a high vacuum, and ions generated in the ion source 1 are led into a high vacuum region 11 to be utilized. The led out ion beam is made to collide with a target material 3 used as to form a film and put on a target holder 4 inclining to the beam, the atoms of the target material 3 are sputtered therefrom according to the ion beam, and deposited on a substrate 7. Coils 6 are provided on both the sides of the substrate 7 to apply a magnetic field in one direction at magnetic film depositing time, a heater 5 is equipped on the back side of the substrate, and the heating temperature of the substrate 7 is regulated by a thermocouple.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method for producing a magnetic alloy film suitable for use in thin film magnetic herad core materials, magnetic sensing devices, and the like.

[Background of the invention]

Conventionally, magnetic device materials include approximately 81M tablets%N1-pe.
Gold alloys (hereinafter referred to as permalloy) and iron-based magnetic alloys are used. When used as a magnetic device, the magnetic anisotropy can be achieved by using electroplating, vapor deposition and sputtering, either alone or in combination, of the magnetic alloy under the action of an orienting magnetic field when forming an IN body. was utilized. A film obtained by such a method exhibits in-plane magnetic anisotropy. The direction in which a magnetic field is applied for orientation during film fabrication returns to the axis of easy magnetization, and as a result, the direction perpendicular to the axis of easy magnetization in the plane of the thin film becomes the axis of hard magnetization. The above-mentioned magnetic film is characterized in that it can perform high-speed switching operations in the high frequency range using this difficult axis direction, and the coercive force in the difficult axis direction is 0.290 e with a film thickness of 2 μm. The magnetic permeability in a high frequency region that does not bleed is 1500 or more.

As a magnetic device, it is generally desirable to have as large a magnetic permeability as possible in the high frequency region, that is, to impart uniaxial anisotropy and to reduce the coercive force in the hard axis direction, since it is not intended to be used at high speeds. Therefore, in order to reduce the coercive force of the magnetic film, it is necessary to reduce the coercive force of the magnetic film itself. Conventionally, the magnetic properties of magnetic films are mainly influenced by the magnetoelastic effect. In particular, attempts have been made to reduce the stress in the film so that the magnetoelastic effect can be ignored. It has also been attempted to reduce the anisotropy of the entire film by subjecting it to a moderate heat treatment. However, when the heat treatment step is started, there is a problem in that the selection of the substrate to be deposited is strictly required, and it also requires a lot of effort and time.

[Purpose of the invention]

The present invention relates to a method for manufacturing a magnetic alloy film that allows a film body having a small coercive force to be manufactured by a simple method.

[Summary of the invention]

It is known that the magnetic properties of a magnetic film vary depending on the composition, film thickness, film formation conditions (substrate temperature, film formation speed, degree of vacuum), underlayer, and heat treatment after film formation. Among the magnetic properties of a magnetic film, coercive force is highly dependent on magnetic anisotropy. According to magnetic theory, magnetic anisotropy is related to magnetoelastic effects, effects due to directional regular lattices, effects of magnetocrystalline anisotropy, effects of shape anisotropy, etc. Generally, the anisotropy of the entire film is given as the sum of the above effects. By the way, in order to reduce the coercive force of a magnetic film, it is necessary to reduce all anisotropies other than the anisotropy caused by the directional regular lattice. Therefore, in order to reduce the anisotropy of the entire film, in addition to the previously attempted reduction of anisotropy using the magnetoelastic effect, films that reduce the effects of magnetocrystalline anisotropy and shape anisotropy, etc. The formation conditions were explored. As a result, it was found that in order to reduce the above-mentioned anisotropic effect, the crystal grains of the film structure must be made smaller.

The present invention was achieved as a result of the discovery that it is extremely effective to increase the degree of vacuum during sputtering and to simultaneously dope hydrogen into the magnetic alloy film in order to reduce the crystal grain size of the film structure. It is something.

That is, the first invention is a method of manufacturing a magnetic alloy film on a substrate by sputtering in a high vacuum of 10"" Torr or more, and the second invention is a method of manufacturing a magnetic alloy film on a substrate by sputtering in a high vacuum of 1O-4T□rr or more. This is a method for manufacturing a magnetic alloy film in which a magnetic alloy film is formed on a substrate and at the same time hydrogen is doped into the magnetic alloy S.

When sputtering is performed in a high vacuum of 10-4 Torr or more, the coercive force of the resulting magnetic alloy film is reduced to 0.40e or less, but sputtering in a high vacuum of 10-'Torr or more poses equipment problems. Especially 10-4 to 10”
It is preferable to use a high vacuum of 6 TOrr.

By performing sputtering in such a high vacuum and simultaneously doping the magnetic alloy film with hydrogen, the coercive force of the magnetic alloy film can be reduced. In this case, it is desirable that the amount of hydrogen doped into the magnetic alloy film be 4 vol % or less.

FIG. 1 shows an example of the configuration of the spool apparatus used in the manufacturing method of the present invention. In order to perform spooling in a high vacuum, a gas such as Ar is introduced into the ion source 1, and the ion source The ions generated in step 1 are extracted into a high vacuum region 11 and utilized, and the extracted ion beam is placed on a target holder 4 at an angle to the beam and collides with the target material 3, which is to become a film. This device uses an ion beam to collect atoms from the target material 3 and deposits them on the substrate 7.The degree of wall thickness inside the chamber is monitored with a vacuum gauge 12. A coil 6 is provided on the side for applying a magnetic field in one direction during magnetic film deposition, and a heater 5 is attached to the back side of the substrate so that the heating temperature of the substrate 7 can be adjusted by a thermocouple. It has become.

In FIG. 1, 8 is a beam converging coil, 9 is a neutrizer, and 10 is a filament.

Therefore, in order to form a laminated magnetic body using this device [4], it is possible to change four types of targets, so that the laminated magnetic body can be easily manufactured by rotating the targets. However, if there is a gap between the targets, impurities other than the target material may be mixed into the film. Therefore, impurities can be prevented by electrically synchronizing the generation of the ion beam and the rotation of the target and turning the beam on and off for a predetermined period of time. Further, a gas such as hydrogen is introduced from the ion source 2 to generate an ion beam, thereby doping the film with the gas.

In such a device, when forming a magnetic layer in which a f& layer is interposed between magnetic alloy films in order to reduce eddy current loss, the following effects can be obtained.

That is, in the conventional method, targets for forming the magnetic alloy layer and the insulating layer within the film of the same device were separately prepared and the substrate was moved to perform the ji-irradiation formation. Furthermore, if one power source is used to supply multiple targets, the 'ii:j source circuits cannot be matched and the specified power cannot be output, resulting in 8-speed operation most of the time.

Furthermore, it is often necessary to install multiple power supplies for multiple targets, complicating the equipment. Such problems are solved by the apparatus shown in FIG.

In the present invention, the magnetic alloy is particularly preferably a nickel-iron alloy or a titanium alloy.

[Embodiments of the invention]

A magnetic field of 6006 or more is applied to the substrate 7 in FIG. 81, and the substrate can be heated to a maximum thickness of 800 C by the heater 5.

Figure 2 shows the thickness 2 of the film formed under the following sputtering conditions.
The relationship between the coercive force in the difficult '1411 direction of a μm permalloy film and the chamber pressure during sputtering is shown.

Target composition 81wt%Nj-Fe Achieved vacuum degree 8
X 10-7 Torr or less Press sputtering time 30 minutesAr i, r, amount 10 800M Acceleration voltage 600Vott (for sputtering) Substrate temperature 300p External magnetic field 600mm on the substrate Distance between substrate targets 100mm As a result, the chamber during sputtering pressure is 5
The magnetic properties are good on the high vacuum side of X 10-'Torr or more. FIG. 3 shows the results of SEM observation of the cross-sectional structure of the formed film. Figure 3 (a) is 5XIO'''”To
This is a cross-sectional structure of the film formed when rr is formed, and this is a coarse structure, and the coercive force in the hard axis direction is 90e. The third same color) is the cross-sectional structure of the formed film at 5×10-II Torr, which is a dense structure and has a coercive force in the hard axis direction of 0.2806. Therefore, when forming a magnetic alloy film by sputtering, it can be seen that the structure is denser and the coercive force is lower on the high vacuum side.

Next 1. We will investigate the effect of doping hydrogen into the film.

Target structure 8 wt% Ti-Fe Ultimate vacuum 8 X 1O-7 Torr or less Press sputtering time 30 minutes Ar gas t 10 800M Hydrogen gas amount Max. 30 800M Acceleration voltage (for sputtering) 600V (for doping) 600V Substrate temperature 200C External magnetic field Substrate Above 6006 Figure 4 shows the thickness 1 of the film formed under the above sputtering conditions.
The relationship between the coercive force in the hard axis direction of a μm iron-based magnetic alloy film and a doped hydrogen meter is shown. From this result, the magnetic properties are good when the amount of doped hydrogen is 4 vol% or less. In order to investigate the cause of this, we compared the cross-sectional structures of a film doped with 1 vol % hydrogen and a film doped with 5 vol 1 % hydrogen, and found that the cross-sectional structure of the film doped with 1 vol 1 % hydrogen had a dense structure.

Next, we formed a laminated magnetic material consisting of a permalloy film and an alumina film. In the apparatus shown in Figure 1, the number of targets is 4.
A laminated magnetic material of permalloy and alumina was formed using the following sputtering conditions.

A time chart of the operating time of the target rotation and the operating time of the ion source at this time is shown in FIG. This made it possible to prevent impurities other than the target material from entering the film.

Ar gasil 10 SCCM Chamber pressure during sputtering 5X10-” Tor
r plate temperature Plate temperature 300C External magnetic field 600e on the substrate Permalloist target 3 alumina targets 1 rotation holding table Residence time Any target rotating Ion source power off As a result, the following magnetic characteristics were exhibited. Here, the total thickness of the magnetic film is 2μ
The magnetic properties were studied when the thickness of the intermediate alumina film was changed using the intermediate layer aluminum and 5Jg Seizo magnetic material.

It can be seen that the greater the total number of layers and the thinner the thickness of the intermediate insulating layer, the more effective the reduction.

〔Effect of the invention〕

According to the present invention, a magnetic alloy film having a small coercive force in the hard axis direction can be obtained by a simple method. Therefore, the magnetic alloy film obtained by the present invention can be used as a uniaxially anisotropic film with high magnetic permeability in the high frequency region for magnetic recording.・It can be applied to the core material of the membrane head and can handle high recording slippage.

[Brief explanation of the drawing]

Figure 1 is a complete configuration diagram of an example of a sputtering apparatus used in the manufacturing method of the present invention, and Figure 2 is the relationship between the coercive force in the difficult axis direction and the chamber pressure during sputtering for a permalloy film with a thickness of 2 μIn. Line diagram showing, Figure 3 Kick (13)
I1. is the cross section of the film formed by changing the chamber pressure during sputtering. Fig. 4 is a diagram showing the relationship between the coercive force in the difficult axis direction of FeTtJ and the hydrogen concentration doped in the film, and Fig. 5 is a diagram showing the relationship between the operating pressure of target rotation and the ion source. ' is a time chart showing the relationship between pressure and pressure. DESCRIPTION OF SYMBOLS 1... Ion source for sputtering, 2... Ion source for doping, 3... Target material, 4... Target holder, 5... Heater, Six River coil, 7...
・iAI&, 8...Beam focusing coil, 9...Nutri ν'-110...Filamen), 11...
・Inside A Menso, 12...Guku gauge. Agent: Masashi Tatsuyuki Unuma Exhaust (A2-person peso link post's 'Hesohe-) Moto ('Tocr) Hakuhe = Shinn Figure 51, page 1 continued 0 Inventor Masanobu Kazono Saiwai-cho, Hitachi City 3-chome-1-1 stock% formula%

Claims (1)

[Claims] 1. A method for producing a magnetic alloy film, which comprises forming a magnetic alloy film on a substrate by sputtering in a high vacuum of 10-'Torr or more. 2. The method of manufacturing a magnetic alloy film according to claim 1, wherein the magnetic alloy film is formed on a substrate by sputtering in a high vacuum of 10-' to 10-' Torr. 3. A method for producing a magnetic alloy film according to claim 1, wherein the magnetic alloy is a nickel-iron alloy or an iron-titanium alloy. 4. The method for manufacturing a magnetic alloy film according to claim 1, wherein an insulating layer is interposed between the magnetic alloy films. 5. A method for manufacturing a magnetic alloy film, which comprises forming a magnetic alloy film on a substrate by sputtering in a high vacuum of 10"" Torr or more and doping hydrogen into the magnetic alloy film at the same time. 6. The method for producing a magnetic alloy film according to claim 5, wherein the magnetic alloy film is formed on a substrate by sputtering in a high vacuum of 10-4 to 10'''l'□rr. 7. The method for producing a magnetic alloy film according to claim 5, wherein the magnetic alloy is a nickel-iron alloy or an iron-titanium alloy. 6. The method of manufacturing a magnetic alloy powder according to claim 5, wherein an insulating layer is interposed between the 8° magnetic alloy films.