High purity hafnium, target and thin film comprising said high purity hafnium, and method for producing high purity hafnium

a technology of high purity hafnium and target, which is applied in the direction of vacuum evaporation coating, coating, sputtering coating, etc., can solve the problems of unstable required characteristics of hafnium raw materials, inability to efficiently eliminate, and inability to efficiently obtain the foregoing high purity hafnium material. , to achieve the effect of high purity, stably manufacturing high purity hafnium, and superior

Inactive Publication Date: 2006-11-30
JX NIPPON MINING & METALS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The present invention provides a way to make high purity hafnium material using a special hafnium sponge with reduced zirconium as the raw material. This process reduces the amount of oxygen, sulfur, and phosphorus in the hafnium material, resulting in a more pure material. The invention also includes a method for making a target and thin film from this high purity hafnium material. This technology is efficient and stable, allowing for the reliable production of high purity hafnium and its related targets and thin films.

Problems solved by technology

In such a case, even zirconium is an impurity, and there is a possibility that the required characteristics of the hafnium raw material may become unstable.
However, since there was no notion of separating hafnium and zirconium as described above, the actual condition is that there is no efficient and stable manufacturing technology for obtaining the foregoing high purity hafnium material with reduced zirconium, and a target and thin film formed from such a material.
Further, since it is difficult to efficiently eliminate the impurities of oxygen, sulfur and phosphorus, this is another reason that high purification has been neglected heretofore.
In particular, materials having a high residual resistance ratio are being demanded, and, since a high purity hafnium material could not be obtained conventionally, it was not possible to sufficiently meet the demands as electronic component materials since the residual resistance ratio was low.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[0029] 100 Kg of commercially available hafnium tetrachloride (HfCl4) shown in Table 1 having a purity of 3N and containing roughly 5000 wtppm of zirconium was used as the raw material, and this was dissolved in 1 L of purified water to create a nitric acid solution.

[0030] This raw material contained 500 wtppm, 40 wtppm and 1000 wtppm of iron, chrome and nickel, respectively, as its main impurities in HfCl4.

[0031] Next, this hafnium raw material (a nitric acid solution) was subject to 4-stage organic solvent extraction using a TBP organic solvent, and neutralization treatment was performed to obtain hafnium oxide (HfO2).

[0032] Further, this hafnium oxide was subject to chlorination to obtain high purity hafnium tetrachloride (HfCl4), and then subject to magnesium reduction to obtain a hafnium sponge as the raw material. This hafnium sponge contained 300 wtppm of zirconium, and the total content of other impurities was reduced to 300 wtppm.

[0033] Next, the obtained hafnium sponge...

example 2

[0037] 100 Kg of hafnium metal raw material (zirconium content of 2 wt %) shown in Table 2 was used and dissolved in nitric-hydrofluoric acid. This raw material contained 15000 wtppm, 8000 wtppm and 5000 wtppm of iron, chrome and nickel, respectively, as its main impurities in the raw material.

[0038] Next, this hafnium raw material was subject to 10-stage organic solvent extraction using a TBP organic solvent, and neutralization treatment was performed to obtain hafnium oxide (HfO2).

[0039] Further, this hafnium oxide was subject to chlorination to obtain high purity hafnium tetrachloride (HfCl4), and then subject to calcium reduction to obtain a hafnium sponge. This hafnium sponge contained 1500 wtppm of zirconium, and the total content of other impurities was reduced to 1000 wtppm.

[0040] Next, the obtained hafnium sponge was used as the raw material, and further subject to two-stage melting via hearth melting and ingot melting with an electron beam to remove volatile elements, g...

example 3

[0043] 100 Kg of hafnium oxide (HfO2) raw material (3N level) shown in Table 3 was used and dissolved in nitric-hydrofluoric acid. This raw material contained 15000 wtppm, 8000 wtppm and 5000 wtppm of iron, chrome and nickel, respectively, as its main impurities in the raw material.

[0044] Next, this hafnium oxide raw material was chlorinated and subject to refining with distillation of 10 or more stages, then further subject to sodium reduction.

[0045] Next, the obtained hafnium was used as the raw material, and further subject to two-stage melting via hearth melting and ingot melting with an electron beam to remove volatile elements, gas components and so on. As a result of the foregoing process, as shown in Table 3, realized was Zr: 500 wtppm, O: 100 wtppm, C: 100 wtppm, N: 20 wtppm, S: 10 wtppm, P: 10 wtppm, others: 30 wtppm.

[0046] Next, the hafnium thus obtained was subject to deoxidation at 1250° C., under argon pressure (4 atm) for 10 hours with molten salt of Ca and CaCl2. ...

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Abstract

The present invention relates to high purity hafnium having a purity of 4N or higher excluding zirconium and gas components and an oxygen content of 40 wtppm or less, and a target and thin film formed from such high purity hafnium, and high purity hafnium having a purity of 4N or higher excluding zirconium and gas components and in which the content of sulfur and phosphorus is respectively 10 wtppm or less. The present invention also relates to a high purity hafnium material which uses a hafnium sponge with reduced zirconium as the raw material, and in which the content of oxygen, sulfur and phosphorus containing in the hafnium is reduced, as well as to a target and thin film formed from such material, and to the manufacturing method of high purity hafnium. Thereby provided is efficient and stable manufacturing technology which enables the manufacture of a high purity hafnium material, and a target and thin film formed from such material.

Description

TECHNICAL FIELD [0001] The present invention relates to a high purity hafnium material in which the content of impurities such as zirconium, oxygen, sulfur and phosphorus contained in the hafnium is reduced, as well as to a target and thin film formed from such high purity hafnium material, and a manufacturing method of high purity hafnium. BACKGROUND ART [0002] Conventionally, there are numerous documents relating to the manufacture of hafnium, and, since hafnium and zirconium are very similar in terms of atomic structure and chemical property, the inclusion of zirconium or the inclusion of zirconium in hafnium was never really acknowledged as a problem as exemplified below. [0003] Hafnium and zirconium are superior in heat resistance and corrosion resistance, and are characterized in that they have a strong affinity with oxygen and nitrogen. And, since the oxides or nitrides thereof have superior stability in high temperatures, they are utilized as fire-resistant materials in the ...

Claims

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Application Information

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Patent Type & AuthorityApplications(United States)
IPC IPC(8): C22C27/00C22B34/14C23C14/34
CPCC22B34/14C23C14/3414C22C27/00
InventorSHINDO, YUICHIRO
OwnerJX NIPPON MINING & METALS CO LTD