Sputtering target

Patent metadata

Field	Value
Publication number	US-11569075-B2
Application number	US-201716337118-A
Country	US
Kind code	B2
Filing date	Sep 8, 2017
Priority date	Sep 29, 2016
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

A sputtering target containing molybdenum and at least one metal from the group tantalum and niobium. The average content of tantalum and/or niobium is from 5 to 15 at % and the molybdenum content is greater than or equal to 80 at %. The sputtering target has at least a matrix with an average molybdenum content of greater than or equal to 92 at % and particles which are composed of a solid solution containing at least one metal from the group of tantalum and niobium, and molybdenum, with an average molybdenum content of greater than or equal to 15 at % and are embedded in the matrix. There is also described a method of producing a sputtering target.

First claim

The invention claimed is:

1. A sputtering target, comprising:
molybdenum and at least one metal selected from the group consisting of tantalum and niobium;
an average content of said at least one metal selected from the group consisting of tantalum and niobium lying between 5 and 15 at %, and a molybdenum content being greater than or equal to 80 at %;
wherein a microstructure of the sputtering target is defined by:
a matrix having particles selected from the group consisting of: a tantalum-rich phase, a niobium-rich phase, and a tantalum-and-niobium-rich phase, said matrix having an average molybdenum content of greater than or equal to 92 at % surrounding said particles and forming a contiguous structure; and
interfaces between said matrix and said particles which are free of oxides;
said particles embedded in said matrix being spatially separated from one another and having a crystal composition made up of:
molybdenum with an average molybdenum content of greater than or equal to 15 at % and less than or equal to 50 at %, and at least one metal selected from the group consisting of tantalum and niobium;
wherein said matrix at least partially comprises a recrystallized microstructure; and
wherein said particles at least partially have a recrystallized microstructure.

2. The sputtering target according to claim 1 , wherein the average molybdenum content of said particles is greater than or equal to 20 at % and less than or equal to 50 at %.

3. The sputtering target according to claim 2 wherein the average molybdenum content of said particles is greater than or equal to 25 at % and less than or equal to 50 at %.

4. The sputtering target according to claim 1 , wherein the target has a forming texture in which at least one of said matrix or said particles has the following predominant orientations:
in a forming direction (110);
in a normal direction: at least one orientation selected from the group consisting of (100) and (111).

5. The sputtering target according to claim 1 , wherein said particles have an average aspect ratio of greater than or equal to 2.

6. The sputtering target according to claim 5 , wherein the average aspect ratio is greater than or equal to 5.

7. The sputtering target according to claim 1 , wherein an average distance between said particles perpendicular to a forming direction is less than or equal to 250 μm.

8. The sputtering target according to claim 1 , wherein an average distance between said particles perpendicular to a forming direction is less than or equal to 50 μm.

9. The sputtering target according to claim 1 , wherein an average grain size of said matrix is less than or equal to 100 μm.

10. The sputtering target according to claim 9 , wherein the average grain size of said matrix is less than or equal to 60 μm.

11. The sputtering target according to claim 1 , consisting of from 5 to 15 at % of said at least one metal selected from the group consisting of tantalum and niobium, balance Mo, and typical impurities.

12. The sputtering target according to claim 1 , wherein said metal is niobium.

13. A method of producing the sputtering target according to claim 1 , the method comprising the following steps:
producing a powder mixture with a molybdenum content of greater than or equal to 80 at % and powder of said at least one metal selected from the group consisting of tantalum and niobium with an average content of between 5 and 15 at %;
consolidating the powder mixture by hot isostatic pressing; and
performing at least one heat treatment step in a temperature range from 1300° C. to 1900° C. for a duration in a range from 1 to 10 hours such that said microstructure of the sputtering target is defined by:
said matrix having said particles selected from the group consisting of: said tantalum-rich phase, said niobium-rich phase, and said tantalum-and-niobium-rich phase, said matrix having the average molybdenum content of greater than or equal to 92 at %; and
said interfaces between said matrix and said particles which are free of oxides;
said particles being embedded in said matrix, said particles being spatially separated from one another and having said crystal composition made up of molybdenum with the average molybdenum content of greater than or equal to 15 at % and less than or equal to 50 at %, and the at least one metal selected from the group consisting of tantalum and niobium;
wherein said matrix at least partially comprises said recrystallized microstructure;
wherein said particles at least partially have said recrystallized microstructure; and
wherein the at least one heat treatment step causes oxides to be transported away from said interfaces between said matrix and said particles resulting in said interfaces between said matrix and said particles being free from oxides.

14. The method according to claim 13 , further comprising performing at least one forming step either:
between the consolidating step and the at least one heat treatment step; or
after the at least one heat treatment step; or
before and after the at least one heat treatment step.

15. The method according to claim 13 , which comprises performing the at least one heat treatment step in a reducing atmosphere.

Assignees

• Plansee Se

Inventors

• Eidenberger-Schober Michael
• Winkler Joerg
• O'Sullivan Michael

Classifications

• B22F2998/10

  Processes characterised by the sequence of their steps · CPC title

• C22C1/045

  Alloys based on refractory metals · CPC title

• H01J37/3491

  Manufacturing of targets · CPC title

• B22F2003/248

  Thermal after-treatment · CPC title

• B22F2201/01

  Reducing atmosphere · CPC title