Erosion resistant yttrium comprising metal with oxidized coating for plasma chamber components

• US 20090162647A1
• Filed: 12/21/2007
• Published: 06/25/2009
• Est. Priority Date: 12/21/2007
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Sun, Jennifer Y., Xu, Li, Collins, Kenneth S., Thach, Senh, Graves, Thomas, Duan, Ren-Guan
• Granted Patent: US 8,129,029 B2
• Time in Patent Office: Days
• US Class Current: 428/336
• CPC Class Codes: C23C 16/4404 Coatings or surface treatment on the inside of the reaction chamber or on parts thereof
• CPC Class Codes: H01J 37/32467 Material
• CPC Class Codes: H01J 37/32477 characterised by the means for protecting vessels or internal parts, e.g. coatings
• CPC Class Codes: Y10T 428/265 1 mil or less

Abstract

An article which is resistant to corrosion or erosion by chemically active plasmas and a method of making the article are described. The article is comprised of a metal or metal alloy substrate having on its surface a coating which is an oxide of the metal or metal alloy. The structure of the oxide coating is columnar in nature. The grain size of the crystals which make up the oxide is larger at the surface of the oxide coating than at the interface between the oxide coating and the metal or metal alloy substrate, and wherein the oxide coating is in compression at the interface between the oxide coating and the metal or metal alloy substrate. Typically the metal is selected from the group consisting of yttrium, neodymium, samarium, terbium, dysprosium, erbium, ytterbium, scandium, hafnium, niobium or combinations thereof.

Claims

1. An article which is resistant to corrosion or erosion by chemically active plasmas, said article comprising:

a metal or metal alloy substrate having a surface; and

an oxide coating comprising an oxide of the metal or metal alloy present on said surface, wherein a structure of the oxide coating is columnar in nature, wherein a grain size of crystals in said oxide coating is larger at an exposed surface of said oxide coating than at an interface between said oxide coating and said metal or metal alloy substrate, and wherein said oxide coating is in compression at said interface between said oxide coating and said metal or metal alloy substrate.

2. An article in accordance with claim 1, wherein the metal or metal alloy comprises yttrium, neodymium, samarium, terbium, dysprosium, erbium, ytterbium, scandium, hafnium, niobium or combinations thereof.

3. An article in accordance with claim 2, wherein said metal or metal alloy is further alloyed with aluminum.

4. An article in accordance with claim 2, wherein said metal is yttrium.

5. An article in accordance with claim 3, wherein said metal or combination thereof includes yttrium.

6. An article in accordance with claim 1, wherein the thickness of the oxide coating ranges from about 1 μ

m to about 500 μ

m.

7. An article in accordance with claim 2, wherein the thickness of the oxide coating ranges from about 1 μ

m to about 500 μ

m.

8. An article in accordance with claim 2, wherein the alloy comprises a dopant selected from the group consisting of zirconium oxide, hafnium oxide, scandium oxide, niobium oxide, samarium oxide, ytterbium oxide, erbium oxide, cerium oxide, neodymium oxide, terbium oxide, dysprosium oxide, and combinations thereof.

9. An article in accordance with claim 2, wherein the alloy comprises a dopant selected from the group consisting of magnesium, aluminum, copper, calcium, and combinations thereof.

10. An article in accordance with claim 2, wherein the dopant comprises a combination of magnesium, aluminum, copper, and calcium, and wherein the concentration range of magnesium ranges from about 10 ppm by weight to about 30 ppm by weight, the concentration range of aluminum ranges from about 10 ppm by weight to about 110 ppm by weight, the concentration range of copper ranges from about 50 ppm by weight to about 300 ppm by weight, and the concentration range of calcium ranges from about 10 ppm by weight to about 800 ppm by weight.

11. An article in accordance with claim 1, wherein an exterior surface of said coating which is an oxide of the metal or metal alloy has a surface roughness ranging from about 0.1 μ

m Ra to about 10 μ

m Ra.

12. An article in accordance with claim 2, wherein an exterior surface of said coating which is an oxide of the metal or metal alloy has a surface roughness ranging from about 0.1 μ

m Ra to about 10 μ

m Ra.

13. A method of fabricating an article having a metal or metal alloy substrate, comprising:

forming an oxide coating on a surface of said metal or metal alloy substrate, wherein forming said oxide coating comprises utilizing a thermal oxidation process, the thermal oxidation process including;

exposing said metal or metal alloy substrate to an ambient atmosphere comprising oxygen, and

forming said oxide coating using a time temperature profile from an initial rapid heating rate to a gradual decrease in heating rate.

14. A method in accordance with claim 13, wherein said time temperature profile comprises:

initially rapidly heating said metal or metal alloy substrate to a desired maximum temperature;

holding said substrate at the maximum temperature for a nominal time period; and

gradually decreasing said substrate temperature until a formation rate of said oxide coating is essentially stopped.

15. An method in accordance with claim 14, wherein the metal or metal alloy comprises yttrium, neodymium, samarium, terbium, dysprosium, erbium, ytterbium, scandium, hafnium, niobium or combinations thereof.

16. An method in accordance with claim 15, wherein said metal or metal alloy is further alloyed with aluminum.

17. An method in accordance with claim 15, wherein said metal or metal alloy is yttrium metal or an alloy of yttrium metal.

18. An method in accordance with claim 16, wherein said metal or combination thereof includes yttrium.

19. A method of fabricating an article in accordance with claim 14, wherein the rate of the rapid initial heating ranges from about 20°

C./min to about 100°

C./min.

20. A method of fabricating an article in accordance with claim 19, wherein the maximum temperature at which the substrate is held ranges from about 700°

C. to about 1050°

C.

21. A method of fabricating an article in accordance with claim 20, wherein the time period during which the substrate is held at the maximum temperature ranges from about 5 minutes to about 5 hours.

22. A method of fabricating an article in accordance with claim 21, wherein the rate of temperature decrease from the maximum temperature ranges from about 1°

C./min to about 0.5°

C./min until the oxidation reaction has essentially stopped.

23. A method of fabricating an article in accordance with claim 22, wherein, the temperature at which the oxidation reaction has essentially stopped ranges from about 400°

C. to about 100°

C.

24. A method of fabricating an article in accordance with claim 23, wherein, subsequent to a discontinuance of the oxidation reaction, the substrate is rapidly cooled to ambient temperature at a cooling rate ranging from about 25°

C./min to about 35°

C./min.

25. A method of fabricating an article in accordance with claim 15, wherein said metal or metal alloy comprises yttrium, and wherein a dopant is added which is selected from the group consisting of zirconium oxide, hafnium oxide, scandium oxide, niobium oxide, samarium oxide, ytterbium oxide, erbium oxide, cerium oxide, neodymium oxide, terbium oxide, dysprosium oxide, and combinations thereof.

26. A method of fabricating an article in accordance with claim 15, wherein said metal or metal alloy comprises yttrium, and wherein a dopant is added which is selected from magnesium, aluminum, copper, calcium, and combinations thereof.