Sputtering target, method of making same, and high-melting metal powder material

• US 20030019326A1
• Filed: 08/21/2002
• Published: 01/30/2003
• Est. Priority Date: 07/07/1999
• Status: Active Grant

• Current Assignee: Hitachi Metals (Thailand) Ltd.
• Original Assignee: Hitachi Metals (Thailand) Ltd.
• Inventors: Nakamura, Hideki, Han, Gang, Murata, Hideo
• Granted Patent: US 6,676,728 B2
• Time in Patent Office: Days
• US Class Current: 75/245
• CPC Class Codes: B22F 1/065 Spherical particles
• CPC Class Codes: B22F 1/14 Treatment of metallic powder mixing with lubricating or binding agents or with organic material B22F1/10
• CPC Class Codes: B22F 2201/013 Hydrogen
• CPC Class Codes: B22F 2202/13 Use of plasma
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 3/15 Hot isostatic pressing
• CPC Class Codes: C22C 1/045 Alloys based on refractory metals
• CPC Class Codes: C23C 14/3414 Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy

Abstract

There is provided a method of making a high-melting metal powder which has high purity and excellent formability and, particularly, of a metal powder of spherical particles made of Ta, Ru, etc. having a higher melting point than iron. There is also provided a target of high-melting metal or its alloy, which is made by the sintering under pressure of these powders and which has high purity and a low oxygen concentration and shows high density and a fine and uniform structure. A powder metal material mainly composed of a high-melting metal material is introduced into a thermal plasma into which hydrogen gas has been introduced, thereby to accomplish refining and spheroidizing. Further, an obtained powder is pressed under pressure by hot isostatic pressing, etc.

Claims

1. A method of refining a metal powder comprising the steps of:

passing a powder metal through a thermal plasma into which a hydrogen gas is introduced; and

performing to high-purify it.

2. A method of making a target comprising the steps of:

introducing a powder material mainly composed of refractory metal into a thermal plasma, thereby to perform refining and spheroidizing; and

sintering an obtained powder under pressure.

3. A method of making a target according to claim 2, wherein said powder material is introduced into a thermal plasma flame into which hydrogen gas has been introduced.

4. A method of making a target according to claim 2, wherein said sintering under pressure is hot isostatic pressing.

5. A method of making a target according to claim 2, wherein the powder material mainly composed of refractory metal is introduced into the thermal plasma into which a hydrogen gas is introduced, thereby to perform refining and spheroidizing;

and sintering the obtained powder under hot isostatic pressing.

6. A sputtering target comprising a sintered powder compact with a relative density of not less than 99%, a purity of not less than 99.999%, and an oxygen concentration of not more than 100 ppm.

7. A sputtering target which can be obtained by performing the pressure sintering of the powder obtained by introducing a powder material mainly composed of a refractory metal into a thermal plasma.

8. A sputtering target according to claim 7, wherein said target can be obtained by introducing a powder into a thermal plasma flame into which hydrogen gas has been introduced.

9. A sputtering target according to claim 7, wherein a shape of particles of said powder introduced for pressure sintering is spherical or analogous to a sphere.

10. A sputtering target according to 7, wherein said metal material is Ta.

11. A sputtering target according to 7, wherein said metal material is Ru.

12. A sputtering target according to claim 7, wherein said target can be obtained by performing the pressure sintering of the powder obtained by introducing a powder material into a thermal plasma into which a hydrogen gas has been introduced, said powder material being mainly composed of Ta and Ru and the shape of particles of said powder material being spherical or analogous to a sphere.

13. A refractory metal powder material, said powder having a purity of not less than 99.999%, an oxygen concentration of not more than 100 ppm, and having a shape of a sphere or analogous thereto.

14. A refractory metal powder material according to claim 13, wherein said powder material can be obtained by introducing the powder material mainly composed of a refractory metal into a thermal plasma flame.

15. A refractory metal powder material according to claim 13, wherein said powder material can be obtained by introducing said powder material into a thermal plasma flame into which hydrogen gas has been introduced.

16. A refractory metal powder material according to claim 13, wherein said powder material mainly composed of a refractory metal is introduced into a thermal plasma flame into which hydrogen gas is introduced, a purity of the powder material is not less than 99.999%, an oxygen concentration thereof not more than 100 ppm, and a shape of said powder material is a sphere or analogous thereto.