Gas distribution plate fabricated from a solid yttrium oxide-comprising substrate

• US 20050056218A1
• Filed: 08/13/2004
• Published: 03/17/2005
• Est. Priority Date: 02/14/2002
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Sun, Jennifer Y., Xu, Li, Thach, Senh, Dempster, James, Pham, Thanh N.
• Granted Patent: US 7,479,304 B2
• Time in Patent Office: Days
• US Class Current: 118/715
• CPC Class Codes: C04B 35/505 based on yttrium oxide
• CPC Class Codes: C04B 41/009 characterised by the material treated
• CPC Class Codes: C04B 41/5353 Wet etching, e.g. with etchants dissolved in organic solvents
• CPC Class Codes: C04B 41/91 involving the removal of part of the materials of the treated articles, e.g. etching
• CPC Class Codes: C23C 16/4404 Coatings or surface treatment on the inside of the reaction chamber or on parts thereof
• CPC Class Codes: C23C 16/4407 Cleaning of reactor or reactor parts by using wet or mechanical methods
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C30B 35/00 Apparatus not otherwise provided for, specially adapted for the growth, production or after-treatment of single crystals or of a homogeneous polycrystalline material with defined structure
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32467 Material
• CPC Class Codes: H01J 37/32862 In situ cleaning of vessels and/or internal parts
• CPC Class Codes: Y10T 428/24273 including aperture
• CPC Class Codes: Y10T 428/24314 Slit or elongated

Abstract

Disclosed herein is a gas distribution plate for use in a gas distribution assembly for a processing chamber, where the gas distribution plate is fabricated from a solid yttrium oxide-comprising substrate, which may also include aluminum oxide. The gas distribution plate includes a plurality of through-holes, which are typically crescent-shaped. Through-holes which have been formed in the solid yttrium oxide-comprising substrate by ultrasonic drilling perform particularly well. The solid yttrium oxide-comprising substrate-typically comprises at least 99.9% yttrium oxide, and has a density of at least 4.92 g/cm³, a water absorbency of about 0.02% or less, and an average grain size within the range of about 10 μm to about 25 μm. Also disclosed herein are methods for fabricating and cleaning the yttrium oxide-comprising gas distribution plate.

Claims

1. A gas distribution plate for use in a gas distribution assembly in a processing chamber, wherein said gas distribution plate is fabricated from a solid yttrium oxide-comprising substrate, and wherein said gas distribution plate includes a plurality of through-holes.

2. A gas distribution plate in accordance with claim 1, wherein said through-holes have been formed in said solid yttrium oxide-comprising substrate by ultrasonic drilling.

3. A gas distribution plate in accordance with claim 2, wherein said through-holes are crescent-shaped.

4. A gas distribution plate in accordance with claim 1, wherein said solid yttrium oxide-comprising substrate comprises at least 99.9% yttrium oxide.

5. A gas distribution plate in accordance with claim 4, wherein said solid yttrium oxide-comprising substrate has a density of at least 4.92 g/cm³.

6. A gas distribution plate in accordance with claim 1 or claim 4 or claim 5, wherein said solid yttrium oxide-comprising substrate has a water absorbency of about 0.02% or less.

7. A gas distribution plate in accordance with claim 1 or claim 4 or claim 5, wherein said solid ttrium oxide-comprising substrate has an average grain size within the range of about 10 μ

m to about 25 μ

m.

8. A gas distribution plate in accordance with claim 1, wherein said solid yttrium oxide-comprising substrate includes impurities at equal to or less than the following maximum concentrations:

90 ppm Al;

10 ppm Ca;

5 ppm Cr;

5 ppm Cu;

10 ppm Fe;

5 ppm K;

5 ppm Mg;

5 ppm Na;

5 ppm Ni;

120 ppm Si; and

5 ppm Ti.

9. A gas distribution plate in accordance with claim 1, wherein at least a portion of a surface of said solid yttrium oxide-comprising substrate is fluorinated.

10. A gas distribution plate in accordance with claim 1, wherein said processing chamber is used for plasma processing.

11. A gas distribution plate in accordance with claim 10, wherein said plasma processing is performed in the presence of halogen-comprising species.

12. A gas distribution plate in accordance with claim 11, wherein said halogen-comprising species include chlorine-comprising species.

13. A method of fabricating a gas distribution plate for use in a gas distribution assembly in a processing chamber, wherein said method comprises fabricating said gas distribution plate from a solid yttrium oxide-comprising substrate.

14. A method in accordance with claim 13, wherein said solid yttrium oxide-comprising substrate further comprises aluminum oxide at a concentration of 10 volume % or less.

15. A method in accordance with claim 13 or claim 14, wherein a plurality of through-holes are created in said solid yttrium oxide-comprising substrate using ultrasonic drilling.

16. A method in accordance with claim 15, wherein said through-holes are crescent-shaped.

17. A method in accordance with claim 13, wherein a surface of said gas distribution plate is treated with fluorine species.

18. A method in accordance with claim 17, wherein a surface of said gas distribution plate is treated with fluorine species using a wet rub technique.

19. A method in accordance with claim 17, wherein a surface of said gas distribution plate is treated with fluorine species by exposing said gas distribution plate surface to a plasma containing fluorine species.

20. A method in accordance with claim 19, wherein said fluorine-containing plasma has a plasma density within the range of about 1×

10⁹ e⁻

/cm³ to about 1×

10⁹ e⁻

/cm³, whereby the surface characteristics of said solid yttrium oxide-comprising substrate are improved with respect to mobile metal impurity content and the amount of loose particles present on said yttrium oxide surface.

21. A method in accordance with claim 20, wherein said fluorine-containing plasma is generated from a source gas comprising CF₄.

22. A method in accordance with claim 13, wherein, prior to said ultrasonic drilling, a layer of a sacrificial material is applied over at least a portion of a surface of said solid yttrium oxide-comprising substrate.

23. A method in accordance with claim 22, wherein said sacrificial material is a polymeric material.

24. A method in accordance with claim 22, wherein said sacrificial material is an inorganic material having a thermal coefficient of linear expansion which is similar to a thermal coefficient of linear expansion of said yttrium oxide.

25. A method in accordance with claim 23 or claim 24, wherein said sacrificial layer has a thickness within the range of about 4 mils to about 6 mils.

26. A method in accordance with claim 13, wherein, subsequent to said ultrasonic drilling, said solid yttrium oxide-comprising substrate is cleaned by a cleaning process which comprises the steps of:

a) saturating exposed surfaces of said solid yttrium oxide-comprising substrate with an inert solvent, wherein said saturation is carried out in an ultrasonic bath;

followed by

b) applying to said solid yttrium oxide-comprising substrate surface a chemically active solvent, whereby contaminants are removed from said yttrium oxide surface.

27. A method in accordance with claim 26, wherein said inert solvent is deionized water.

28. A method in accordance with step a) of claim 27, wherein said solid yttrium oxide-comprising substrate is immersed in a deionized water ultrasonic bath for a period of about 5 minutes to about 30 minutes.

29. A method in accordance with claim 26, wherein said chemically active solvent is a dilute acid solution.

30. A method in accordance with claim 29, wherein said dilute acid solution includes HF and HNO₃.

31. A method in accordance with claim 30, wherein said dilute acid solution comprises about 0.1 to about 5 volume % HF, about 1 to about 15 volume % HNO₃, and about 80 to about 99 volume % deionized water.

32. A method in accordance claim 26, wherein, subsequent to said step b) application of said dilute acid solution, said solid yttrium oxide-comprising substrate is immersed in a deionized water ultrasonic bath for a period of about 30 minutes to about 2 hours.

33. A method in accordance with claim 32, wherein, subsequent to said step b), said method further includes the step of:

c) immersing said solid yttrium oxide-comprising substrate in a deionized water ultrasonic bath for a period of about 40 minutes to about 1 hour.

34. A method in accordance with claim 26, or claim 29, or claim 32, or claim 33, wherein, subsequent to said step c), said method further includes the step of cleaning said solid yttrium oxide-comprising substrate using CO₂ snow.