JPS6224605A - Amorphous magnetic thin film - Google Patents

Abstract

PURPOSE:To remove thermal instability and imperfection possessed by amorphous materials and make surface conditions hard to rust, by using materials with specific composition containing halogen. CONSTITUTION:Materials with element composition basically shown in a formula QXRy M(100-x-y) are used, wherein, Q is one kind or more of F, Cl, Br, and I in halogen elements, M is one kind or more of B, C, Al, Si, P, Ti, V, Cr, Mn, Ni, Zr, Nb, and Mo, R is one or two kinds of Fe and Co, with x=0.1-25 atom% and 50atom%>=x+y>=10atom%.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an amorphous magnetic a-film containing halogen gas, which can be applied to various thin-film magnetic heads for magnetic recording.

Conventional technology Amorphous magnetic thin films have shown a significant increase in demand in recent years, and are used not only for metals and alloys, but also for oxides, borides, carbides,
Thin films of compounds such as nitrides are also easily produced in various gas atmospheres.

Film formation of metals and alloys is widely performed because the raw materials used and the shape of the target are easy to process, but film formation technology for compounds is difficult due to the gas elements and light elements contained.
Their production methods are different.

In addition, there are many compounds containing halogen, especially F, including magnetic materials (halide magnetic materials), photoelectric materials (electroluminescence, photochromic), and optical materials (fluoride glasses). There are active substances (fluorine-based plastics) and biologically active substances (pesticides, pharmaceuticals, pigments, and poisonous drugs), and they range from highly active to stable.

In the field of magnetic materials, it is called a halide magnetic material, and since FSCl and 3r are 1111i anions, when combined with iron group magnetic ions with a valence of 2 or more, the component ratio concentration becomes 1:2. The magnetic critical temperature becomes below room temperature. Therefore, there are few magnetic materials that are important for applications.

Halide magnetic materials are MF2, MF3, AMF3
(perovskite type) and A2MF4 bonding types, and types of magnetic materials include antiferromagnetic materials, metamagnetic materials, colorless transparent ferromagnetic materials, and insulating magnetic materials. These are compounds in which halogen elements and metal elements are combined as crystals.
This is a field with high halogen content.

However, all of these have a crystalline structure, and there is no amorphous structure.

Problem 1 to be solved by Akira Akira: The present invention solves the problem of amorphous magnetic W containing halogen gas.
By providing an I film, the thermal instability and imperfections of amorphous materials are eliminated, and the surface condition is made rust-resistant and solid.

The present invention provides an amorphous magnetic thin film having a novel composition containing such halogen gas.

Means for Solving the Problems The present invention is an amorphous magnetic thin film as described below.

-X-V of QX MV Rrl) (However, Q is a halogen element and F, Cl, Br, I
Any one or more of the following, M is 81C, AI, S
i, P, Ti, V, Cr, Mn.

Any one type or a combination of two or more of Nt, Zr, Nb, and Mo, R is any one type of Fe, Co, or a combination of 211, x = 0.1 to 25 at% 50 atoms ≧ x + y ≧ It is 10 atom%. ) Such a 7s film can be obtained by a reactive deposition method.

In the present invention, halogen gas, F, CI, and Sr.

By containing (2), a magnetic thin film having an amorphous structure based on Fe and Go is produced.

If the content m of halogen gas in Q is less than 0.1 at%, there is no effect of halogen gas inclusion or amorphous formation effect, and 2
Since the formation of halogen compounds starts when the amount exceeds 5 at.%, the content m of halogen gas was limited to 0.1 to 25 at.%. Also, M is an amorphous forming element Q,! : Necessary for improving the magnetic properties of the tafII thin film. Its content is reasonable with Q, from 10 atomic % to 50 atomic %. R
Any one type or the combination of two types of l”e and Co,
It is a basic element of magnetic materials.

Here, the reactive film formation method is defined as a film formation technique in which at least one composition of the compound thin film produced thereby is in the gas phase. ”.

Film forming methods include, for example, Rf, [)C, facing target, ion beam, vapor deposition, cluster ion beam,
Tri-mag high-speed sputtering may be used, but reactive sputtering will be described as an example.

In reactive sputtering, it is generally believed that the combination of gold m atoms and reactive gas occurs on the target and substrate. Of course, collisional combinations occur in the discharge space, but these are collisions in three-dimensional space, such as collisions in two-dimensional space such as collisions of moving atoms on the substrate surface, and collisions of ions, etc. with targets. The frequency is small compared to that of clusters, and the temperature of the plasma is high, so even if clusters or atoms collide, there is nowhere for the thermal energy generated by the combination to escape, and they eventually break down. Of course, it is safe to assume that the energy of flying atoms decreases during this process of collision, combination, and decomposition. Therefore, the energy of atoms colliding with the substrate is also weaker than in the case of no reaction.

Next, the halogen gas used as the reactive gas will be explained. Dry etching technology is a technology using halogen gas plasma. Plasma etching is used for various semiconductor devices and integrated circuits that use silicon as a substrate, especially LS.
I. It has been widely put into practical use as a basic technology for VLSI.

In an etching reaction using plasma, the main reaction is a chemical reaction in a so-called non-equilibrium state, and the etching characteristics are greatly influenced not only by the material to be etched and the reaction gas, but also by the surface condition of the material.

In these etchings, inert gas (Ar, NOSH
e, etc.) and those using C as reactive gas radicals.
F4, CF4 +02, CFa+Hz, C3F3, C
Some use G+ 4.8C13.

The basic reaction of plasma etching is that when a reactive gas is introduced in a reduced pressure atmosphere and high frequency power is applied, a glow discharge is generated and a low-temperature non-equilibrium gas plasma is generated. This plasma contains electrons and ions, which are the basic constituent particles, and most of them are electrically neutral atoms and molecules.

In many cases, they are in an excited state, have high chemical activity, and easily cause chemical reactions. As an example of a basic gas used in plasma etching, CF4 gas is thermally stable due to its covalent nature, and exhibits high resistance to ultraviolet rays and radiation.

In a glow discharge plasma using CF4, CF4 dissociates as follows to generate F atoms in an excited state with high chemical activity.

CF4 He −-+CFx +F”He −→C〇F4 (F': F atom in an excited state with high activity) The active halogen atoms generated in the plasma in this way are chemically related to the material to be etched. Etching occurs by reacting with other substances to produce volatile or high vapor pressure reaction products.

As mentioned above, halogen gas is widely used in the area of plasma etching, but it is also used as a reactive gas for sputtering.
In other words, no attempt has been made to include halogen gas during film formation.

As a reactive film forming method, it is possible to introduce active pure halogen gas into the chamber, but the problem is that the gas itself is very active and can cause accidents such as corrosion, fire, and human inhalation. If it can be prevented, the reactive film forming method will naturally work.

However, it is difficult to manufacture pure halogen gas cylinders, and only low-concentration cylinders can be made even for mixed gases such as Ar, and the lifespan of the cylinders is approximately 6 months due to corrosion.
There are many problems, including the fact that the insurance is only guaranteed for about a month.

Therefore, the halogen gas-containing thin film of the present invention is an unprecedented film that safely contains halogen gas as described above. Therefore, in the present invention, halogen gas as a reactive gas and The compound gas is generated by decomposing a halogen compound. In general, reactive film deposition methods include a method in which a reactive gas is introduced from the outside, a method in which reactive gas is generated within the same chamber, or a composite target in which a compound is placed in a mosaic pattern on the target to form a film. .

First, in a composite target, the evaporation rate of the fluoride placed on the target is high, making it difficult to form a film stably. In general, fluorides tend to have a lower melting temperature than oxides and nitrides, and are thought to be easily decomposed by plasma.Actually, when FeF3 powder is used as a target for press molding and sputtering, it can be easily decomposed even at low power. The color changes, the white surface turns blackish brown, and a change in properties is clearly observed. Therefore, it is difficult to form a homogeneous film by sputtering for a long time using a composite target.

Next, the method of introducing halogen gas from outside the chamber through the piping system causes great damage to the cylinder and the gas control system of the piping system, and is extremely dangerous from a long-term perspective.

From the above, the present invention decomposes and generates halogen gas from highly pure fluoride in the same chamber and provides it for use.This is a safe and effective method, and the required amount can be easily controlled. Halogen gas generated within the chamber can be easily rendered harmless through post-treatment.

Figure 1 shows, as an example, 2.0k used in the production of the present invention.
w Opposing DC sputtering device (target diameter 80φ) and halogen gas generation 1. OkwRf electrode (target diameter 8
0φ) is shown. D in the same chamber 1
An Rf electrode 5 having a halogen compound as a target 4 is arranged between the C-facing target 2 and the substrate 3. Ar gas is introduced from the gas inlet 6, and the Rf electrode 5 is heated at an appropriate degree of vacuum.
Halogen gas is decomposed and generated from the halogen compound target 4 above. In the DC facing target 2, elements are ejected from the target set on the electrode by the impact of Ar + halogen elements, react with the halogen elements while flying to the substrate, and the active elements easily combine with each other. When deposited on the substrate, a large change occurs compared to non-reactive sputtering.

[Example] Example 1 Using a facing target DC sputtering apparatus as shown in FIG.
%). FC on Rf Tsutaat 4! F3
Used by press molding a halogen compound. After evacuating the inside of vacuum chamber 1 to 5x 10-' Torr, Ar
Introduce gas and adjust the inside of the tank to 2x 1O-3T orr. For example, set the Rf output for halogen gas generation to 3
By changing the DC output at 00W, it is possible to easily change the contents of B and F as shown in FIG.

In this case, when the F content is 20 at %, an amorphous structure is exhibited, but when it exceeds 25 at %, fluoride begins to be produced. Reactive sputtered films of various compositions prepared and Fe508
Table 1 shows the results of measuring the magnetic properties of the unreacted sputtered film of MI using a vibrating magnetometer and a direct P, fIi measurement device.
Shown below.

Table 1 A film having this magnetic property has a high saturation magnetization BS, a good squareness ratio Sr/Bs (x 100), and a low protective power Hc, so it can be used as a transformer material, etc.

Example 2 As in Example 1, co, lr, and Nb were attached to the opposing target. The Rf tube also uses FeF3.

As in Example 1, the magnetic properties of the unreacted sputtered film and the reactive sputtered film were measured using a vibrating magnetometer and a DC magnetization measuring device, and the results were as shown in Table 2.

Table 2 A film with this magnetic property has good coercive force and squareness ratio, and since it is a thin film containing F, it has excellent high frequency properties, and can be applied to various IS magnetic heads for magnetic recording.

Effects of the Invention According to the present invention, an amorphous structure can be easily formed by containing a halogen gas, and a magnetic thin film that is thermally stable and has an excellent surface condition can be obtained.

That is, as the content of halogen gas increases,
The surface of the thin film is chemically strengthened, improving resistance to acids such as hydrochloric acid and oxidation resistance to moisture.

As shown in Figure 3, the obtained magnetic thin film has a squareness ratio Br /Bs (*100) of 97 when compared to the unreacted film.
%, and the improvement in magnetic properties is remarkable.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an apparatus suitable for producing the thin film of the present invention, and FIG. 2 is a graph showing variations in the contents of B and F in Example 1. FIG. 3 is a graph comparing the halogen gas reactivity and the magnetism of an unreactive film. 1...Chamber, 2...DC opposing target. 3...Substrate, 4...Target, 5...RfrB
Pole, 6...Gas inlet.

Claims (1)

[Claims] (1) An amorphous magnetic thin film characterized by having a composition basically represented by the following formula. Q_xM_yR_(_1_0_0_-_x_-_y_) (However, Q is a halogen element, F, Cl, Br, I
Any one or two or more of the following, M is B, C, Al, Si
, P, Ti, V, Cr, Mn, Ni, Zr, Nb, Mo
Any one type or a combination of two or more types, R is Fe, C
x=0.1 to 25 atom% and 50 atom≧x+y≧10 atom%. )