Multi-block sputtering target and associated methods and articles

Patent metadata

Field	Value
Publication number	US-9334562-B2
Application number	US-201213467323-A
Country	US
Kind code	B2
Filing date	May 9, 2012
Priority date	May 10, 2011
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

A sputtering target that includes at least two consolidated blocks, each block including an alloy including molybdenum in an amount greater than about 30 percent by weight and at least one additional alloying ingredient; and a joint between the at least two consolidated blocks, the joint being free of any microstructure due to an added bonding agent (e.g., powder, foil or otherwise), and being essentially free of any visible joint line the target that is greater than about 200 μm width (e.g., less than about 50 μm width). A process for making the target includes hot isostatically pressing, below a temperature of 1080° C., consolidated perform blocks that may be surface prepared (e.g., roughened to a predetermined roughness value) prior to pressing.

First claim

What is claimed is:

1. A method for making a sputtering target, comprising the steps of:
a. providing first and second at least partially consolidated powder metal blocks each having a prepared surface, and each including an alloy including molybdenum in an amount greater than about 30 percent by weight and at least one additional alloying element;
b. contacting the prepared surface of the first block directly with the prepared surface of the second block in the absence of any bonding agent between the directly contacted surfaces to form a contacted joint structure; and
c. isostatically pressing the contacted structure at a temperature that is less than about 1080° C. at a pressure and for a time sufficient to realize a consolidated joint between the first and second blocks that is essentially free of any joint line greater than 200 μm width and provides a structure that has a transverse rupture strength per ASTM B528-10, of at least about 600 MPa.

2. The method of claim 1 , wherein the step of providing includes a step of forming the first and second blocks from an alloy that includes molybdenum, and at least one alloying element selected from titanium, chromium, niobium, tantalum, tungsten, zirconium, hafnium, vanadium lithium, sodium, potassium or any combination thereof.

3. The method of claim 2 , wherein the step of providing includes a step of forming the first and second blocks from an alloy that includes molybdenum and titanium, and optionally, chromium, niobium, tantalum, tungsten, zirconium, hafnium, vanadium lithium, sodium, potassium or any combination thereof.

4. The method of claim 3 , wherein the step of providing includes a step of forming the first and second blocks from an alloy that includes about 30 to about 70 at % molybdenum and the balance titanium, exclusive of impurities.

5. The method of claim 4 , wherein the step of providing includes a step of milling one or more edge surfaces of the first and second blocks to an average surface roughness (Ra) of less than about 150 microinches (3.8 μm) to define opposing prepared surfaces for forming the contacted joint structure.

6. The method of claim 5 wherein the step of isostatically pressing includes pressing at a temperature between about 500 and about 1080° C. while the contacted structure is encapsulated in a sealed vessel.

7. The method of claim 6 , wherein the step of isostatically pressing includes pressing at a pressure of at least about 70 MPa, while the contacted structure is encapsulated in a sealed vessel.

8. The method of claim 7 , wherein the step of isostatically pressing includes maintaining a pressure of about 80 to about 140 MPa at a temperature of about 700° C. to about 1080° C. for a time of about one to about six hours while the contacted structure is encapsulated in a sealed vessel.

9. The method of claim 8 , wherein the step of isostatically pressing is performed under conditions sufficient so that the resulting consolidated joint provides a structure that has a transverse rupture strength per ASTM B528-10, of at least about 620 MPa.

10. The method of claim 9 , wherein a resulting oxygen weight concentration of the blocks of the sputtering target is between about 1000 ppm and 3500 ppm.

11. The method of claim 1 , wherein the resulting sputtering target has:
i) a volume % of substantially pure molybdenum phase of 35% to 48%, a volume % of substantially pure titanium phase of 2% to 15%, and a volume % of molybdenum/titanium phase of 40% to 60%.

12. The method of claim 1 , wherein the resulting sputtering target includes a target body defined by the first and second metal blocks and the consolidated joint, wherein the throughout the target body there is a substantially continuous and uniform distribution of the three phases, and the target body is essentially free of any joint line greater than about 50 μm width.

13. The method of claim 12 , wherein the first and second at least partially consolidated powder metal blocks each have a prepared edge surface characterized by a surface roughness (Ra) of less than about 5.1 μm.

14. The method of claim 13 , wherein the at least one additional alloying element includes titanium.

15. The method of claim 14 , wherein the target body includes a substantially pure phase of the at least one additional alloying element present in an amount less than about 10 vol %.

16. The method of claim 15 , wherein the target body includes an alloy of molybdenum and the at least one additional alloying element including a β-phase of molybdenum and titanium, in an amount greater than about 40 vol % of the alloy, of the target, or both.

17. The method of claim 15 , wherein the target has a sputtering surface of at least about 1.5 m 2 , and the first and second metal blocks are joined end-to-end.

18. A method for making a sputtering target of comprising the steps of:
a. providing a first block and a second block, wherein the first and second blocks are at least partially consolidated powder metal blocks, have substantially the same composition, and include an alloy including molybdenum in an amount greater than 30 percent by weight and at least one additional alloying element;
b. milling an edge surface of the each of the first and second blocks to an average surface roughness of less than 3.8 μm to define opposing milled edge surfaces for forming a contacted joint structure;
c. contacting the milled edge surface of the first block directly with the milled edge surface of the second block in the absence of any bonding agent between the directly contacted surfaces to form the contacted joint structure; and
d. isostatically pressing the contacted joint structure at a temperature between about 700 and about 1000° C. while the contacted structure is encapsulated in a sealed vessel to realize a consolidated joint between the first and second blocks that is essentially free of any joint line greater than 200 μm width and provides a structure having a transverse rupture strength per ASTM B528-10, of at least about 600 MPa;
wherein the target has a largest dimension of at least 1.3 meters.

19. A method for making a sputtering target comprising the steps of:
a. providing first and second at least partially consolidated powder metal blocks each having a prepared edge surface characterized by a surface roughness (Ra) of less than about 5.1 μm, and each block having substantially the same composition and including an alloy including molybdenum in an amount greater than about 30 percent by weight and at least one additional alloying element;
b. contacting the prepared surface of the first block directly with the prepared surface of the second block in the absence of any bonding agent between the directly contacted surfaces to form a contacted joint structure; and
c. isostatically pressing the contacted joint structure to realize a consolidated joint between the first and second blocks that is essentially free of any joint line greater than 200 μm width, and wherein the sputtering target has a transverse rupture strength per ASTM B528-10, of at least about 600 MPa.

20. The method of claim 19 , wherein the step of providing includes a step of forming the first and second blocks from molybdenum, and at least one alloying element selected from titanium, chromium, niobium, tantalum, tungsten, zirconium, hafnium, vanadium lithium, sodium, potassium or any combination thereof.

21. The method of claim 20 , wherein the step of providing includes a step of forming the first and second blocks from 30 to 70 at % mo

Assignees

• Rozak Gary Alan
• Gaydos Mark E
• Starck H C Inc

Inventors

• Rozak Gary Alan
• Gaydos Mark E

Classifications

• B22F1/00

  Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties · CPC title

• C23C24/04

  Impact or kinetic deposition of particles · CPC title

• C22C1/04

  by powder metallurgy (C22C1/08 takes precedence) · CPC title

• B22F3/15

  Hot isostatic pressing · CPC title

• C23C14/3414 Primary

  Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy · CPC title