Reduced contaminant gas injection system and method of using

• US 20070235136A1
• Filed: 03/30/2006
• Published: 10/11/2007
• Est. Priority Date: 03/30/2006
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Enomoto, Takashi, Urakawa, Masafumi, Hagihara, Masaaki, Heller, Edward, Hamamoto, Shinji, Ko, Akiteru, Laflamme, Arthur H.
• Granted Patent: US 7,743,731 B2
• Time in Patent Office: Days
• US Class Current: 156/345.340
• 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 and configured to receive said flow of said process gas through an inlet and distribute said flow of said process gas within a plenum to a plurality of openings in fluid communication with said process space, wherein said gas distribution system comprises a process gas diffuser located at said inlet to said gas distribution system and configured to diffuse the momentum of said flow of said process gas into 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; and

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

2. The treatment system of claim 1, wherein said process gas diffuser comprises a divergent passage having an inlet coupled to an outlet of said process gas supply system and an outlet coupled to said plenum, and wherein the outlet comprises an opening that is larger than the opening of said inlet.

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

4. The treatment system of claim 2, wherein said divergent passage comprises a conical passage having a half angle less than or equal to approximately 18 degrees.

5. The treatment system of claim 2, wherein said divergent passage comprises a conical passage having a half angle less than or equal to approximately 15 degrees.

6. The treatment system of claim 2, wherein said process gas diffuser further comprises an orifice plate at said outlet of said divergent passage.

7. The treatment system of claim 6, 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.

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

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

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

11. The treatment system of claim 9, wherein said coating contains at least one column III element.

12. The treatment system of claim 9, wherein said coating contains a material including Al₂O₃, Sc₂O₃, Sc₂F₃, YF₃, La₂O₃, Y₂O₃, or DyO₃.

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

14. The treatment system of claim 1, wherein said gas distribution system is formed of quartz, alumina, aluminum nitride, sapphire, silicon, silicon nitride, silicon carbide, or carbon, or a combination of two or more thereof.

15. The treatment system of claim 1, wherein said gas distribution system is formed of a dielectric material.

16. The treatment system of claim 15, further comprising:

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 process gas, and

wherein said gas distribution system is disposed between said upper electrode and said holder.

17. The treatment system of claim 16, wherein said gas distribution system is formed of quartz, sapphire, alumina, aluminum nitride, silicon, silicon carbide, or silicon nitride, or a combination of two or more thereof.

18. The treatment system of claim 16, wherein said plenum comprises a cylindrical volume having a height less than or equal to approximately 5 mm.

19. The treatment system of claim 16, wherein said plenum comprises a cylindrical volume having a height less than or equal to approximately 3 mm.