JPS63130767A - Production of thin ta amorphous alloy film - Google Patents

Abstract

PURPOSE:To obtain a thin Ta amorphous alloy film having a high crystallization temp. and excellent mechanical characteristics, corrosion resistance, etc., by bombarding ions to a target material consisting of a Ta alloy contg. Si at a specific ratio and forming a thin film of the target material in a gaseous state on a substrate. CONSTITUTION:After the inside of a vacuum chamber 3 is evacuated 4 to order of 10<-7>Torr, gaseous Ar is introduced 7 therein until order of 10<-3>Torr is attained. Sputtering of the target 1 is then started by turning on a high-frequency power supply 8. The target 1 consists of the Ta alloy contg. Ta in a 60-90at% compsn. range and is kept cooled by a cooling water introducing pipe 10. The substrate 2 is kept cooled down to a room temp. or below by introduced 11 liquid nitrogen N2 12. The structure of the thin Ta-Si alloy film formed on the substrate 2 is evaluated by an X-ray diffraction method. As a result, sharp diffraction peaks by crystals are not observed in the compsn. range of 60-90at% Ta in the compsn. of the thin film. Since a broad halo pattern is obtd., it is verified that the thin amorphous film is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing an amorphous alloy having a high crystallization temperature.

(Prior Art) In recent years, various amorphous materials have been developed and are attracting a lot of attention in the field of metal materials. Unlike conventional crystalline alloys, these alloys do not have a crystalline structure, and many of their properties are not found in conventional metal materials, such as mechanical properties, wear resistance, corrosion resistance, and soft magnetism. Due to its excellent electrical properties, various uses are being developed as a material that can replace crystalline metals, and materials suitable for these uses are also being developed. These alloys have conventionally been generally produced by a liquid quenching method such as a single roll method.

(Problems to be Solved by the Invention) The biggest problem with amorphous alloys is that they are thermally unstable. This is due to the fact that the amorphous state is a thermodynamically non-equilibrium metastable state, and can be said to be the fate of amorphous alloys. In other words, each amorphous alloy generally has its own specific crystallization temperature, and when that temperature is exceeded, it changes to a more thermally stable crystalline alloy, and the superiority seen in the amorphous state is lost. This results in the loss of all the thin adhesion properties. This crystallization temperature varies depending on the material, but
Generally, it is known that the value is about 0.4 to 0.6 times the melting point measured in absolute temperature. Therefore, in order to obtain an alloy with a high crystallization temperature, an alloy with a high melting point must be made amorphous.

The Ta--Si alloy has an extremely high melting point of about 2300°C or higher. For this reason, Ta
-8i amorphous alloy has a crystallization temperature of 800°C ~
The temperature was extremely high at 960°C, making it possible to significantly improve the problems of amorphous alloys (Patent Application No. 61-01238
No. 5). Furthermore, this Ta-Si amorphous alloy has excellent mechanical properties such as high strength and high hardness that are characteristic of general amorphous alloys, so it can be used as a wear-resistant material, for example.
In addition, applications such as materials for electrodes that involve temperature rises are possible.

However, Ta-
Since the Si-based amorphous alloy has a ribbon-like shape with a width of several mm to several cm, there is a problem in that it is impossible to obtain an amorphous alloy with a wide area. Furthermore, it has not been possible to form the amorphous alloy in the form of a thin film on a certain substance using conventional liquid quenching methods.

The present invention solves the problems of the prior art and provides a method for producing a Ta-based amorphous alloy thin film that has a high crystallization temperature and has excellent mechanical properties, corrosion resistance, etc. With the goal.

(Means for solving the problems) The present invention is expressed by the formula Ta1-, SiX, where x=0.
1-0.4 is made amorphous by bombarding the target material with ions and ejecting the target material in a gaseous state to form a thin film on the substrate. This is a method for producing a Ta-based amorphous alloy thin film.

(Function) In Ta-Si alloys, as shown in Examples later, T
The present inventor has discovered that an amorphous alloy can be formed in a composition range in which a is 60 at% to 90 at%. When the composition is outside this range, almost no amorphous structure is observed, and all the excellent properties characteristic of amorphous alloys are lost.

The crystallization temperatures of these amorphous alloys are as high as 800° C. or higher, corresponding to their high melting points. In addition, the mechanical properties of these amorphous alloys are high strength and high hardness, as is generally seen in amorphous alloys.

Also, in terms of corrosion resistance, it has corrosion resistance comparable to that of Ta.

The manufacturing method according to the present invention involves ionizing gas atoms or molecules such as argon gas in a high electric field or high-frequency electric field, and further accelerating them by the electric field to cause them to collide with the target surface and knock out the target material from the target surface. Since a thin film of the target material is formed on the substrate, it is possible to form a homogeneous alloy thin film over a large area.

In addition, the target material is Ta-S with the target composition.
An i-alloy or a composite material in which Ta and Si are combined in an appropriate area ratio is used. Therefore, the composition of the obtained alloy thin film can be easily changed by changing the composition of the target alloy or by appropriately changing the area ratio of the composite material, so that the desired composition can be changed. Amorphous Material (Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an example of an apparatus for producing the Ta-based amorphous alloy thin film of the present invention. The apparatus shown in FIG. 1 is a high-frequency dipole magnetron sputtering apparatus, and in the figure, 1 is a target and 2 is a substrate. As target 1, composite Targetera F was used in this example. That is, an appropriate number of Si plates each having a square side of 10 mm and a thickness of 1 mm were placed on a Ta target having a diameter of 100 mm and a thickness of 5 mm. T
On a, the Si plates were set to be distributed as uniformly as possible. By changing the number of Si sheets, the composition of the resulting alloy thin film was changed. Board 2 has a length of 5
Glass with a diameter of 0 mm, a width of 25 mm, and a thickness of 0.2 mm was used.

When producing a thin film, first, open the valve 5 and heat the vacuum chamber 3 to 1O-7 Torr using the vacuum pump 4.
Evacuate to r level of vacuum. Thereafter, the barrier pull leak valve 6 is opened and argon gas is introduced from the argon gas introduction pipe 7 until the pressure reaches 10-3 Torr. In this state, the high frequency power source 8 is turned on to start sputtering. The input power was 500W. At this time, the target 1 is water-cooled by the cooling water introduction pipe 10. Further, the substrate 2 is cooled to below room temperature by the liquid nitrogen 12 introduced by the liquid nitrogen introduction pipe 11. This means that in order to make the Ta-based alloy thin film amorphous,
This is because the substrate needs to be cooled with a coolant such as water or liquid nitrogen. When the substrate temperature was measured by the thermometer 15 through the thermocouple 14, it was found that the substrate was cooled down to -180°C. For the first hour of sputtering, the shutter 9 was closed and press sputtering was performed. In this sputtering apparatus, a permanent magnet 13 is attached to the back side of the target, and high-speed sputtering can be performed by the magnetic field created by this on the target surface. After the press sputtering was completed, the shutter 9 was opened to form a thin film on the substrate. Thin film preparation was performed for 1 hour. The thickness of the obtained thin film is
It was about 511m.

The structure of the obtained Ta-Si alloy thin film was analyzed using X-ray diffraction method.
In the composition range of 0 at % to 90 at %, no sharp diffraction peak due to crystals was observed in any of the thin films, and a broad halo pattern was obtained, confirming that an amorphous alloy thin film was obtained. Table 1 shows the crystallization temperatures of these samples determined by differential thermal analysis. Both are 800°C
This shows a high crystallization temperature. In addition, the mechanical properties of these samples include Vickers hardness of 800 to 1500.
It showed excellent properties in that it was within the range of . Furthermore, even when these samples were left in concentrated hydrochloric acid, concentrated nitric acid, concentrated sulfuric acid, and concentrated aqua regia for one day, no signs of corrosion were observed, and no change in weight was observed.

In this example, a method for producing a Ta-based amorphous alloy thin film using a high-frequency bipolar magnetron sputtering device was introduced. However, when producing an amorphous thin film, other sputtering methods, such as ordinary DC Polar sputtering method, high frequency bipolar sputtering method, triode or quadrupole sputtering method, bias sputtering method,
It is also possible to use the ion beam irradiation method, reactive sputtering method, etc.

(Effects of the Invention) As explained in detail above, the method for producing a Ta-based amorphous alloy thin film according to the present invention is an amorphous alloy that has a high crystallization temperature and has excellent mechanical properties, corrosion resistance, etc. A thin film can be easily obtained and the effect is great.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing an example of an apparatus for producing a Ta-based amorphous alloy thin film of the present invention. In the figure, 1 is a target, 2 is a substrate, 3 is a chamber, 4 is a vacuum pump, 5 is a vacuum valve, 6 is a barrier pull leak valve, 7 is an argon gas introduction tube, 8 is a high frequency power supply, 9 is a shutter, and 10 is a 11 is a liquid nitrogen introduction pipe for cooling the substrate; 12 is liquid nitrogen; 13 is a permanent magnet; 14 is a thermocouple; and 15 is a thermometer.

Claims (1)

[Claims] It is expressed by the formula Ta_1−_xSi_x, where x=0.1~
An alloy having a composition of 0.4 is made amorphous using a sputtering device that forms a thin film on a substrate by bombarding a target material with ions and ejecting the target material in a gaseous state. A method for producing a Ta-based amorphous alloy thin film.