Reduced contaminant gas injection system and method of using

• US 7,743,731 B2
• Filed: 03/30/2006
• Issued: 06/29/2010
• Est. Priority Date: 03/30/2006
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Enomoto, Takashi, Heller, Edward, Hamamoto, Shinji, Laflamme, Arthur H. Jr., Ko, Akiteru, Urakawa, Masafumi, Hagihara, Masaaki
• Primary Examiner(s): Zervigon; Rudy
• Application Number:
  US11/392,949
• Publication Number:
  US 20070235136A1
• Time in Patent Office: 1,552 Days
• Field of Search: 118/723.E, 156/345.33, 156/345.34, 156/345.43, 156/345.45
• US Class Current: 118/723.00E
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32449 Gas control, e.g. control of the gas flow
• CPC Class Codes: H01L 21/32136 using plasmas
• CPC Class Codes: H01L 21/32137 of silicon-containing layers
• CPC Class Codes: H01L 21/67069 for drying etching

Abstract

A gas injection system includes a diffuser to distribute a process gas in a processing chamber. The gas injection system may be utilized in a polysilicon etching system involving corrosive process gases.

Claims

1. A treatment system, comprising:

a process chamber, including a process space;

a process gas supply system in fluid communication with said process chamber and configured to introduce a flow of a process gas to said process chamber;

a gas distribution system coupled to said process chamber, said gas distribution system comprises a housing and a gas distribution plate coupled to said housing, the combination of which defines a plenum which receives said flow of said process gas through an entrance to said plenum and distributes said flow of said process gas to a plurality of openings in said gas distribution plate that are in fluid communication with said process space, wherein said housing and said gas distribution plate are formed of a dielectric material, wherein said gas distribution system comprises a process gas diffuser that comprises a divergent passage having an inlet coupled to an exit of said process gas supply system, and an outlet coupled to said plenum and located at said entrance to said plenum of said gas distribution system, said process gas diffuser diffuses the momentum of said flow of said process gas into said plenum, and wherein said outlet of said process gas diffuser comprises a cross-sectional area that is larger than a cross-sectional area of said inlet of said process gas diffuser and smaller than a cross-sectional area of said plenum;

a holder coupled to said process chamber and configured to support a substrate in said process chamber for exposure to said process gas;

a vacuum pumping system coupled to said process chamber and configured to evacuate said process chamber; and

an upper electrode coupled to said process chamber and disposed opposite said holder, wherein said upper electrode is coupled to a radio frequency (RF) generator and configured to form plasma in said process space by coupling RF power from said RF generator to said upper electrode and through said gas distribution system to said process gas in said process space, and wherein said gas distribution system is disposed between said upper electrode and said holder.

2. The treatment system of claim 1, wherein said divergent passage comprises a conical passage having a half angle less than or equal to approximately 20 degrees.

3. The treatment system of claim 1, wherein said divergent passage comprises a conical passage having a half angle less than or equal to approximately 18 degrees.

4. The treatment system of claim 1, wherein said divergent passage comprises a conical passage having a half angle less than or equal to approximately 15 degrees.

5. The treatment system of claim 1, wherein said process gas diffuser further comprises an orifice plate, separate from said gas distribution plate, at said outlet of said divergent passage.

6. The treatment system of claim 5, wherein said divergent passage comprises a cylindrical inlet having an inlet diameter and a cylindrical outlet having an outlet diameter that is larger than said inlet diameter.

7. The treatment system of claim 6, wherein said inlet diameter steps out to said outlet diameter.

8. The treatment system of claim 1, further comprising a coating disposed on at least one interior surface of said gas distribution system.

9. The treatment system of claim 8, wherein said coating is an anodic layer.

10. The treatment system of claim 8, wherein said coating contains at least one column III element.

11. The treatment system of claim 8, wherein said coating contains a material including Al₂O₃, Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, Y₂O₃, or DyO₃.

12. The treatment system of claim 1, wherein said gas distribution system is formed of aluminum having a coating thereon.

13. The treatment system of claim 1, wherein said housing, said gas distribution plate, and said process gas diffuser are formed of quartz, alumina, aluminum nitride, sapphire, silicon, silicon nitride, silicon carbide, or carbon, or a combination of two or more thereof.

14. The treatment system of claim 1, wherein said plenum comprises a cylindrical volume having a height less than or equal to approximately 5 mm.

15. The treatment system of claim 1, wherein said plenum comprises a cylindrical volume having a height less than or equal to approximately 3 mm.

16. The treatment system of claim 1, wherein:

said outlet of said process gas diffuser is positioned opposite from a portion of said gas distribution plate void of any of said plurality of openings.