JPH0581670B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing a Ta--W based 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. All the characteristics that were previously acquired are lost. This crystallization temperature varies depending on the material, but is generally 0.4 to 0.4 of the melting point measured in absolute temperature.
It is known that the value is about 0.6 times. 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-B alloy has an extremely high melting point of approximately 2300°C or higher. For this reason, the Ta-Si-B amorphous alloy produced by the liquid quenching method has a very high crystallization temperature of 800℃ to 1000℃, which greatly improves the problems of amorphous alloys. It became possible to do so (Special Application No. 61-012385). Furthermore, this Ta-Si-B-based amorphous alloy has excellent mechanical properties such as high strength and high hardness characteristic of general amorphous alloys, so it can be used as a wear-resistant material, for example. It can also be applied to materials for electrodes that are subject to temperature increases. However, when the Ta-Si-B amorphous alloy is actually used in a high-temperature environment, aging becomes a problem, so the operating temperature range is limited to a maximum of about 600°C. . Furthermore, Ta-
Si-B amorphous alloys have shapes ranging from several mm to several cm in width.
Because of the ribbon shape, there was a problem in that it was not possible 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 the conventional liquid quenching method. The present invention solves the problems of the prior art, has a high crystallization temperature, can withstand higher temperature environments than the Ta-based amorphous alloy, and has improved mechanical properties, corrosion resistance, etc. The object of the present invention is to provide a method for producing an excellent Ta-W amorphous alloy thin film. (Means for solving the problem) The present invention provides an alloy represented by the formula (Tal-xWx)1-yBy, where x=0.01 to 1 and y=0.1 to 0.4,
By bombarding the target substance with ions and ejecting the target substance in a gaseous state,
This is a method for producing a Ta--W based amorphous alloy thin film, which is characterized by forming a thin film on a substrate to make it amorphous. (Function) In the Ta-W-B alloy thin film, Ta and W or W are 60 at% to 90 at%, as shown in Examples later.
The present inventors have discovered for the first time that an amorphous alloy can be formed within the composition range. When the composition is outside this range, almost no amorphous structure is observed, and all the excellent properties characteristic of amorphous alloys are lost. In addition, the range of x was limited to 0.01 or more because
This is because in this range, the crystallization temperature becomes higher than when only Ta is added or when a small amount of W is added. The crystallization temperatures of these amorphous alloys are all as high as 1000°C or higher, corresponding to their high melting points. Additionally, the mechanical properties of these amorphous alloys are high hardness, as is generally seen in amorphous alloys. Also, in terms of corrosion resistance, it has corrosion resistance comparable to that of Ta and W. 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 then accelerating them by the electric field to cause them to collide with the target surface and knock out the target substance from the target surface. Since the thin film is formed on the substrate, it is possible to form a homogeneous alloy thin film over a large area. In addition, as a target substance,
A Ta-W-B ternary alloy or a composite material in which Ta, W and B are combined in an appropriate area ratio is used. Therefore, the composition of the obtained alloy thin film is
By changing the composition of the target alloy,
Further, since the area ratio of the composite material can be easily changed by appropriately changing the area ratio, an amorphous alloy thin film having a desired composition can be easily obtained. (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-W based amorphous alloy thin film of the present invention. The apparatus shown in FIG. 1 is a high frequency two-pole magnetron sputtering apparatus, and in the figure, 1 is a target and 2 is a substrate. As target 1, a composite target was used in this example. That is, the diameter is 100mm and the thickness is 5mm.
On top of the Ta target, an appropriate number of W and B plates with a square size of 10 mm on a side and a thickness of 1 mm were placed. At this time, W and B are placed on top of the Ta target.
The plates were set so that they were distributed as evenly as possible. By changing the number of W and B,
The composition of the resulting alloy thin film was varied. For the substrate 2, glass was used with a length of 50 mm, a width of 25 mm, and a thickness of 0.2 mm. When producing a thin film, first open the valve 5 and move the vacuum chamber 3 with the vacuum pump 4.
Evacuate to a vacuum level of 10 ^-7 Torr. Thereafter, the variable leak valve 6 is opened and argon gas is introduced from the argon gas introduction pipe 7 until the pressure reaches the 10 ^-3 Torr level. In this state, the high frequency power source 8 is turned on to start sputtering. The input power was 500W. At this time, target 1 is
It is water-cooled by a cooling water introduction pipe 10. Further, the substrate 2 is cooled to below room temperature by liquid nitrogen 12 introduced through a liquid nitrogen introduction pipe 11. This is because in order to make the Ta--W alloy thin film amorphous, it is necessary to cool the substrate with a coolant such as water or liquid nitrogen. When the substrate temperature was measured with a thermometer 15 through a 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. This sputtering device is
A permanent magnet 13 is attached to the back side of the target, and the magnetic field created by this on the target surface enables high-speed sputtering.
After the press sputtering was completed, the shutter 9 was opened to form a thin film on the substrate. Thin film preparation was carried out for 1 hour. The thickness of the obtained thin film was about 5 μm. The structure of the obtained Ta-W-B alloy thin film was evaluated by X-ray diffraction. As a result, the composition of the thin film
In the composition range of Ta and W, and W in the range of 60 at% to 90 at%, no sharp diffraction peaks due to crystals were observed in any of the thin films, and a broad halo pattern was obtained, indicating that amorphous alloy thin films were obtained. It was confirmed that Table 1 shows the crystallization temperatures of these samples determined by differential thermal analysis. Both samples
It shows a high crystallization temperature of over 1000℃, and Ta
-100℃ more than the case of Si-B amorphous alloy
It can be seen that the crystallization temperature is ~200°C higher. Furthermore, these samples maintained their amorphous structure even after being annealed at 800°C for 1000 hours, proving that they are highly heat-resistant amorphous alloys. Furthermore, the mechanical properties of these samples showed excellent properties with a Vickers hardness ranging from 900 to 1600. 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.

【table】

[Table] In this example, a method for producing a Ta-W amorphous alloy thin film using a high-frequency two-pole magnetron sputtering device was introduced. However, when producing an amorphous thin film, other sputtering methods, That is, the usual DC two-pole sputtering method, high-frequency two-pole sputtering method, triode or quadrupole sputtering method, bias sputtering method, ion beam sputtering method, reactive sputtering method, etc. may be used. (Effects of the Invention) As explained in detail above, Ta according to the present invention
The method for producing a -W-based amorphous alloy thin film has a high crystallization temperature and can easily produce an amorphous alloy thin film with excellent mechanical properties, corrosion resistance, etc., and is highly effective.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of an apparatus for producing a Ta-W based amorphous alloy thin film of the present invention. In the figure, 1 is the target, 2 is the substrate, 3 is the chamber, 4 is the vacuum pump, 5 is the vacuum valve,
6 is a variable leak valve, 7 is an argon gas introduction pipe, 8 is a high frequency power supply, 9 is a shutter, 10
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] 1 (Tal−xWx)1−yBy, x
An alloy with a composition of = 0.01 ~ 1, y = 0.1 ~ 0.4,
By bombarding the target substance with ions and ejecting the target substance in a gaseous state,
Using a sputtering device to form a thin film on a substrate,
A method for producing a Ta-W based amorphous alloy thin film, which is characterized by making it amorphous.