JPS60218820A - Manufacture of fe-al-si system alloy thin film - Google Patents

Abstract

PURPOSE:To obtain Fe-Al-Si system alloy thin film which is excellent in magnetic characteristic and has high hardness by executing the sputtering under inactive gas including N2. CONSTITUTION:An Fe-Al-Si system alloy thin film is formed on crystallized glass substrate using Ar gas as inactive gas and executing the sputtering by the magetron sputtering method through mixture of N2 gas to such Ar gas. With increase of a rate of N2 included in the Ar gas, the Fe-Al-Si system alloy thin film obtained is superior not only in hardness and durability to rust, etc. but also in the magnetic characteristic such as permeability and saturated magnetic flux density, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing an Fe-A7-Si alloy thin film, and more specifically, a method for producing an Fe-A#Si alloy thin film. This invention relates to improvements in sputtering methods.

[Background technology and its problems]

For example, in magnetic recording and reproducing devices such as VTJ video stage recorders, the density and frequency of recording signals are increasing. .

A so-called metal tape using ferromagnetic metal powder such as Co or Ni, a ferromagnetic metal material coated on a base film by vapor deposition, or a so-called vapor deposition tape have come to be used. Since this type of magnetic recording medium has a high residual magnetic flux density Br, the head material of the magnetic head used for recording and reproduction is also required to have a high saturation magnetic flux density B8. For example, ferrite materials, which are conventionally widely used as magnetic head materials, have a low saturation magnetic flux density Bs, and permalloy has problems in wear resistance.

On the other hand, with the above-mentioned high-density recording, the track width of the recording track recorded on the magnetic recording medium is also becoming narrower, and in response to this, the track width of the magnetic head is also required to be extremely narrow. has been done.

Therefore, conventionally, so-called composite magnetic heads have been developed in which a magnetic alloy thin film serving as a magnetic core is deposited on a non-magnetic substrate such as ceramic, and the track width is the thickness of this magnetic alloy thin film, and in which the magnetic alloy thin film or conductive thin film is used as an insulator. A thin film magnetic head with a multilayer structure using thin films has been proposed, and "et kll +" is a magnetic alloy thin film used in this type of magnetic head.
It is not preferable to use S + in magnetic heads that require processing at temperatures above the main component.

[Means for solving problems]

Therefore, the present inventors developed a thermally stable Fe-AA-8i
As a result of intensive research to improve the magnetic properties and hardness of Fe-Al-8i alloy thin films, we found that Fe-Al-8i alloy thin films obtained by sputtering in an inert gas containing N2 gas have high magnetic permeability and saturation. We have come to the knowledge that it has high hardness without reducing magnetic flux density.

The present invention has been made based on such knowledge, and is characterized in that sputtering is performed in an inert gas containing N2.

The above-mentioned sputtering method may be any method as long as it is normally performed, such as bipolar direct current sputtering, triode sputtering, quadrupole sputtering, magnetron sputtering, high frequency sputtering, bias sputtering, Examples include asymmetric AC sputtering, facing target sputtering, and ion sputtering.

In the present invention, the atmosphere in which the sputtering is performed is important. That is, sputtering is normally performed in an inert gas, but in the present invention, sputtering is performed in an inert gas.
Sputtering is performed in an inert gas containing 2.

As the above-mentioned inert gas, (e), Ne, Ar, etc. can be used, and among them, it is preferable to use Ar. 0.01 to 40 volumes of N2 are mixed into these inert gases. If the above-mentioned N2 content is less than 0°O1 volumetric square, a sufficient effect cannot be expected, and if the above-mentioned content exceeds 40 volumetric squares, there is a risk that the magnetic permeability etc. will decrease. The active gas contains not only N2 but also 02
May contain.

Furthermore, the gas pressure during the sputtering is lX l
O-'~2. OXIQ-'TorrO) range is preferred. The above gas pressure is 2. OXIQ”
When Torr is exceeded, the sputtering speed becomes slow.

On the other hand, Fe -AA- formed by the above sputtering
The composition range of the 8i alloy thin film is sufficiently practical if Al is 2 to IO weight ratio, Si is 3 to 16 weight ratio, and the balance is Fe, and preferably A14 to 8 weight ratio, Si 5
~11% by weight, the balance being Fe. In addition, the obtained Fe-
The thickness of the A7-8i alloy thin film is IooA ~ 50
It is clever that it is within the range of μ.

Furthermore, it is also possible to replace a part of the Fe with at least one of co and N1.

The saturation magnetic flux density Bs can be increased by replacing a portion of Fe with Co. In particular, the maximum saturation magnetic flux density Bs can be obtained by replacing 40% of Fe with Co. The substitution amount of Co is 0 to 6 with respect to Fe.
It is preferably within the range of 0% by weight.

On the other hand, by replacing a portion of the Fe with N1, the magnetic permeability can be maintained at a high level without decreasing the saturation magnetic flux density Bs. The amount of Ni replaced is Fe
It is preferably within the range of 0 to 40% by weight.

Furthermore, various elements may be added as additives to the Fe-AA-8i alloy thin film described above. Elements used as the above additives include group ■a elements such as Y, Ti
, Zr, Hf and other group a elements, V.

Nova group elements such as Nb and Ta; ■A group elements such as Cr, Mo, and W; ■A group elements such as Mn, Tc, and Re; Ru, R+h, Pd, Os, Ir
, Platinum group elements such as Pt, mb group elements such as Ga and In,
■B group elements such as Ge and Sn, Sb, Vb group elements such as Bi, and La.

Examples include lanthanum series elements such as Ce, Nd, and Gd. These additives are added in an amount of 0 to 10% by weight based on the Fe-A6-Sj alloy. If the amount of the additive added exceeds the 0 weight ratio, the magnetic properties of the resulting thin film will deteriorate.

By the way, various methods can be considered to adjust the composition range of the obtained Fe-A#-8i alloy thin film, such as (1) method of using an alloy ingot having a predetermined composition as a target (2) Examples include a method in which targets for each component are prepared and the composition is controlled by the number of these targets; and (3) a method in which targets for each component are prepared and the composition is adjusted by controlling the output applied to these targets.

Method (1) above uses Fe, AA! , Si, other additives, substitution metals, etc. are weighed out to a predetermined content, melted in advance in a high-frequency melting furnace, etc. to form an alloy ingot, and this alloy ingot is used as a target during sputtering. It is used as a.

In method (2) above, targets of Fe, A#, and Si are prepared respectively, and the composition of the thin film obtained is controlled by increasing or decreasing the number of these targets during sputtering. For example, a large disc-shaped Fe target is prepared, and a small Al plate and a Si
Arrange the boards. Then, the composition is controlled by increasing or decreasing the number of the AA plates or Si plates. In this case, an A6 target may be created as the large disc-shaped target, and small Fe plates and h plates may be arranged on this A7 target, or a Si target may be created as the large disc-shaped target, and the S
An Fe plate and an AA plate may be arranged on the i-target. Further, as the large disk-shaped target, an Fe-4A' alloy target or an Fe-8i alloy target having a predetermined composition is used.
An alloy target and an AA-8i alloy target are prepared, and a Si plate or an An plate is placed on these alloy targets.
Fe may be arranged.

In the method (3) above, targets such as Pe, All, and 810) are prepared, a voltage is applied to each of these targets, and the composition of the obtained alloy thin film is controlled by controlling this voltage. In this case, it is preferable to perform sputtering while rotating the substrate on which the alloy thin film is to be deposited, so as to uniformize the composition of the alloy thin film deposited on the substrate.

By performing sputtering in an inert gas containing N2 as described above, a Fe-A/-8i alloy thin film having excellent magnetic properties and high hardness is produced. That is, according to the experiments of the present inventors, Fe-A/- obtained by sputtering in an inert gas containing N2
It was found that the 8i-based alloy thin film can obtain high magnetic permeability without reducing the saturation magnetic flux density of 13s, and also has a small coercive force Hc. For example, it has been found that the magnetic permeability at ]MHz is about twice that of a material sputtered in a normal inert gas. Also,
An increase in specific electrical resistance was also observed, and it was found that deterioration in magnetic permeability was suppressed, especially in the high frequency range. Furthermore, Fe-AA obtained by sputtering in an inert gas containing N2! It was also found that the hardness of the -Si-based alloy thin film was significantly improved, and it also became extremely resistant to rust.

By the way, regarding the role played by N2 in the present invention,
The details are unknown, but the above N2 is FeAA! -8i
These Fe penetrate into the alloy thin film.

It is presumed that this contributes in some way, such as by forming nitrides of A/ and Si.

Hereinafter, specific examples of the present invention will be described, but it goes without saying that the present invention is not limited to these examples.

〔Example〕

Example 1 Si with a purity of 99.9999%, A/with a purity of 99.99%
, Fe with a purity of 99.99% is used as a raw material, and after weighing and separating these raw materials, it is melted in a vacuum using a high-frequency melting furnace, and then poured into a mold and formed into a mold with a diameter of 50 m.
An electrode target with a thickness of 1 nm and a thickness of 1 nm was prepared. The composition of this target was Fe5zAlqSixt.

Sputtering was performed by magnetron sputtering using the above target and following the sputtering conditions below.

Sputtering conditions RF power: 800W Target-substrate distance: 30mm Substrate temperature: ~20°C (water cooling) Ultimate vacuum: 3XIOTorr Gas pressure: 4XIOTOrr Film thickness: Approximately 6μm According to the above sputtering conditions, Ar gas is used as an inert gas, and N2 is added to the Ar gas. Sputtering was performed after mixing. Here, the amount of N2 mixed in is controlled by partial pressure,
Sputtering is performed while changing the ratio of N2,
A Fe-AA-8i alloy thin film was formed on a crystallized glass substrate. Obtained re-AA! -8i alloy thin film 5
After heat treatment at 50° C. for 1 hour, hardness, specific electrical resistance, magnetic permeability, and saturation magnetic flux density were measured.

FIG. 1 is a characteristic diagram showing the relationship between the proportion of N2 contained in Ar gas and the hardness of the obtained Fe-A/-8i alloy thin film. Here, the hardness was measured as Vickers hardness, and was measured by molding with a weight of 50 g for 15 seconds. ' From FIG. 1, it can be seen that as the proportion of N2 contained in the Ar gas increases, the hardness of the obtained Fe-A/-8i alloy thin film increases significantly. For example, the hardness H of a Fe-kl-8i alloy thin film obtained by sputtering in Ar gas containing no N2
v = 630, whereas A containing 5 volumes of N2
Fe-A obtained by sputtering in r gas
The hardness of the /-8i alloy thin film was Hv-1120.

Next, Figure 2 shows the proportion of N2 contained in Ar gas and the electrical resistance (specific resistance) of the obtained Fe-A#-8i alloy thin film.
FIG. The above electrical resistance was measured by a four-terminal method and was determined as a specific resistance when the electrical resistance of a Fe-AIl-8i alloy thin film obtained by sputtering in an Ar-free N2 gas was set to 1.0. It is a value corrected for film thickness.

This specific resistance is an important element in estimating the magnetic permeability in the high frequency region of the obtained Fe-Al-8i alloy thin film. In other words, in general, a concentric induced current (eddy current) flows in a magnetic body in response to a temporally changing magnetic flux.
This eddy current causes a decrease in magnetic permeability, especially in the high frequency range. For example, it is known that the resistivity of a normal sendust alloy material is 85 μΩ·cin, which is smaller than the resistivity of an amorphous alloy material of 150 μΩ·cm, and therefore the magnetic permeability in a high frequency region tends to be low. Therefore, the higher the resistivity of the obtained re-AJ-8i alloy thin film, the more sophisticated it is.

Here, it can be seen from FIG. 2 that as the proportion of N2 contained in the Ar gas increases, the specific resistance of the obtained Fe-AJ-8i alloy thin film increases linearly.

Therefore, it is estimated that the Fe-Al-8i alloy thin film obtained by sputtering in an inert gas containing N2 is advantageous in terms of magnetic permeability in a high frequency region.

FIG. 3 is a characteristic diagram showing the relationship between the proportion of N2 contained in Ar gas and the magnetic permeability at 1 MHz of the obtained Fe-Al-8i alloy thin film. Note that the magnetic permeability was measured using a permeance meter.

It can be seen from FIG. 3 that as the proportion of N2 contained in the Ar gas increases, the magnetic permeability of the obtained Fe--A/Si-based alloy thin film increases significantly. For example, N
It can be seen that when the ratio of 2 is 8 volumes, the magnetic permeability reaches approximately 3 times.

Furthermore, FIG. 4 shows the frequency characteristics of magnetic permeability of a Fe-Al-8i alloy thin film obtained by sputtering in Ar gas containing N2. In addition, in this Figure 4, curve a has a ratio of N2 of 0 volume, and curve A has a ratio of N2 of 2.
The volume coefficient, curve C, is the ratio of N2, and the curve d is N2.
The ratio of N2 is 5 volumes per month, and the song IJe represents a case where the ratio of N2 is 20 volumes.

From this Figure 4, it can be seen that in the Fe-AI-8i alloy thin film obtained by sputtering in Ar gas containing N2, the relative It can be seen that high magnetic permeability can be obtained. In particular, it has been observed that as the proportion of N2 increases, the decrease in magnetic permeability at high frequencies tends to decrease; for example, when the proportion of N2 is 20 vol. Although the magnetic permeability is low, it is considered to have sufficient practicality in the frequency range of 20 to 3 QMHz.

FIG. 5 is a characteristic diagram showing the relationship between the proportion of N2 contained in Ar gas and the saturated 8-flux density of the obtained Fe-Al-8i alloy thin film.

What should be noted in Fig. 5 is that N in Ar gas
An improvement in the saturation magnetic flux density of the Fe-AI-8i alloy thin film obtained by introducing No. 2 was observed.

This is extremely useful compared to the case where, when additives are added to improve the temperature characteristics of hardness, magnetic permeability, etc., the saturation magnetic flux density generally decreases. In this example, not only was the decrease in saturation magnetic flux density suppressed, but the saturation magnetic flux density was even improved.

Furthermore, when a Fe-AJ-8i alloy thin film obtained by sputtering with 2.5 volumes of N2 mixed in Ar gas was immersed in city water for 85 hours and the state of rust was examined, it was found that the metal mirror surface It was found that the condition was maintained and almost no rust was observed.

As is clear from the above measurement results, A containing N2
re-AJ obtained by sputtering in r gas
-8i alloy thin films are not only excellent in terms of durability such as hardness and rust, but also have excellent magnetic properties such as magnetic permeability and saturation magnetic flux density, and are suitable for use in magnetic heads, etc. It is suitable for this purpose.

Example 2 Al on a pure iron target as a target.

Composite target with Si or FeszMtS
A/, Si or M using a composite target in which Fe, Al, and Si are placed on the in target.

Fe-Al-5 with various compositions were sputtered by changing the numbers of Sl, Fe, AJ, and Si and performing sputtering in 5 volumes of Ar gas containing N2 and Ar gas not containing N2.
An i-based alloy thin film (thickness approximately 5μ77L) was produced.

The transmittance and Vickers hardness of the obtained Fe-kl-8i alloy thin film were measured. The magnetic permeability was measured using a permeance meter, and the Vickers hardness was measured under a load of 50 g. Furthermore, the obtained Fe-AA! -S
The composition of the i-based alloy thin film was analyzed for F e and A 6 r S' using an X-ray microanalyzer. Here, the sputtering in Ar gas containing N2 was considered to be the same as the sputtering in Ar gas.

The results are shown in Table 1.

Table 1 From this Table 1, it can be seen that Samples 1 to 10 produced by sputtering in Ar gas containing Nz5 by volume, Comparative Sample 1 to Comparative Sample 10 produced by sputtering in Ar gas It can be seen that the magnetic permeability is higher than that regardless of the composition, and in particular, the frequency characteristics are also improved from the magnetic permeability values at I MHz and 5 MHz. Further, it can be seen that the Vickers hardness is also improved by about 200 to 300.

Example 3 AA on a pure iron target as a target.

Fe-Al
-A Si-based alloy thin film was manufactured.

The magnetic permeability, Vickers hardness, and saturation magnetic flux density of the obtained Fe-Al-3i alloy thin film were measured. Second result
Shown in the table.

Table 2 From Table 2, Samples 11 and 12 produced by sputtering in Ar gas containing N25 volumetric coefficient are compared to Comparative Sample 11 and Comparative Sample 1 produced by sputtering in Ar gas.
Improvements in magnetic permeability and Vickers hardness were seen compared to 2.
Further, no decrease in saturation magnetic flux density was observed.

[Brief explanation of the drawing]

Figure 1 shows the proportion of N2 contained in Ar gas and the resulting F
A characteristic diagram showing the relationship between the Vickers hardness of an e-AA-Si alloy thin film, and Figure 2 shows the relationship between the ratio of N2 contained in Ar gas and the specific resistance (N2) of the resulting Fe-Al-8i alloy thin film.
Figure 3 is a characteristic diagram showing the relationship between the ratio of N2 contained in Ar gas and the resulting Fe -AA -l of Si-based alloy thin film
A characteristic diagram showing the relationship between magnetic permeability at MHz, Figure 4 is N
A characteristic diagram showing the frequency characteristics of the magnetic permeability of a Fe-AA-8i alloy thin film obtained by sputtering in Ar gas containing 2. Figure 5 shows the ratio of N2 contained in Ar gas and the resulting Fe-A FIG. 2 is a characteristic diagram showing the relationship between the saturation magnetic flux density of a #-8i alloy thin film. Patent Applicant Sony Corporation Representative Patent Attorney Kodo Koike 1) Ei Mura - Iyo (44;/,) -→ ll2 (weight〆) 1 3rd male 醐・ ((prison'one Aan -m- ->Milj'a (Ml-lx) ← Illusion + /Fk4-/ ) -1Δ Continuation of page 1 [Phase] Inventor Tatsuo Kumura 6-5-6 Kitashinyo, Tokyo Parts Industry Sony Magne Products Co., Ltd. In-house procedure amendment (voluntary) (old) 2. Name of the invention Method for producing Fe-Al-5i alloy thin film 3. Relationship with the case of the person making the amendment Patent applicant address 6-7 Kitashinyo, Tokyo Parts Co., Ltd. No.35 Name (2
18) Sony Corporation (Name) Representative
Norio Ohga 4, Agent address Φ 2-6-4 Toranomon, Minato-ku, Tokyo 105 Voluntary 6, "Detailed description of the invention" column and drawings 7 of the specification to be amended, Contents of the amendment (7) -1) The statement "40% by volume" on the 9th line of page 6 of the specification is corrected to "20% by volume." (7-2) The statement "40% by volume" on the 11th line of page #16 of the specification is corrected to "20% by volume." (7-3) The statement "8% by volume" on the 20th line of page 15 of the specification is corrected to "5% by volume." (7-4) The statement “3 times” in the first line of page 16 of the specification is changed to “
2.5 times”. (7-5) The sentences from "In addition," on the 5th line of page 16 of the specification tIs to "as shown" on the 1/410th line of the same page are corrected as follows. ``In addition, in this Figure 4, the proportion of islands in curve a is 0% by volume, the proportion of N2 in curve A is 2% by volume, the proportion of N2 in curve C is 5% by volume, and the proportion of N2 in curve d is 5% by volume. (7-6) The statement "20 volume %" on page 16, line 19 of the specification is corrected to "rlO volume %." (7-7) Fig. 3 0 10 2O N2 (volume %) - Fig. 4 1'l"ll' - (MHz) - Procedural amendment (voluntary) 10/8/1980 Patent - Office Commissioner Shiga Gakuden 1. Indication of the case 1982 Patent Application No. 75369 2. Name of the invention Method for manufacturing Fe-Al-5i alloy thin film 3. Person making the amendment ゛Relationship to the case Patent applicant address Tokyo Parts District Kitashinyo 6-7-35 Name (2
18) Sony Corporation (Name) Representative
Norio Ohga 4, Agent address: 6-6, Toranomon 2-6-4, Minato-ku, Tokyo 105, "Detailed description of the invention column" of the specification to be amended Contents of the amendment (7-1) Description The description "r residual magnetic flux density Br" in the third line of the second page is corrected to "coercive force HcJ."(7-2') The description "r residual magnetic flux density Br" in the third line of the second page is corrected to "coercive force HcJ." Correct a certain description to "recorded magnetic pattern." (7-3) The statement "extremely" in the fourth line of page 4 of the specification is deleted. (7-4) In the first line of page 7 of the specification, “Si weighs 3 to 16.”
The rsi is 3 to 16% by weight, according to a certain statement.'' (7-5) The statement "The above are listed" from the 1st line of the 8th page of the specification to the 10th line of the same page is amended as follows. “The elements used as the above additives include Sc,
■A group elements including lanthanum series elements such as 1', La, Ce, Nd, Gd, Ti, Zr, Hf
Group IVa elements such as V. Va group elements such as Nb and Ta, ■a such as Or, No', W, etc.
Group elements, ■A group elements such as Mn, Tc, Re, etc., R
Examples include platinum group elements such as u, Rh, Pd, Os, It, and Pt, mb group elements such as Ga and In, TVb group elements such as Ge and Sn, and Vb group elements such as sb. (7-6) The statement "output" on the second line of page 9 of the specification is corrected to "power output." (7-7) The description r800WJ in the 14th line of Specification Section 12 is corrected to rlooWJ. (7-8) From the 9th line on page 14 of the specification to the 1st line on the same page, the statement ``The value is expressed as a specific resistance.'' is replaced with ``The value is expressed as a specific resistance.'' ”, he corrected. (that's all)

Claims (1)

[Claims] Fe-AA! characterized by performing sputtering in an inert gas containing N2! - A method for producing a Si-based alloy thin film.