Plasma processing device

• US 20040094094A1
• Filed: 09/29/2003
• Published: 05/20/2004
• Est. Priority Date: 03/28/2001
• Status: Abandoned Application

• Current Assignee: Tadahiro Ohmi, Tokyo Electron Limited
• Original Assignee: Tadahiro Ohmi, Tokyo Electron Limited
• Inventors: Ohmi, Tadahiro, Goto, Tetsuya, Hirayama, Masaki, Sugawa, Shigetoshi
• Application Number:
  US10/473,302
• Publication Number:
  US 20040094094A1
• Time in Patent Office: Days
• US Class Current: 118/723.0MW
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32238 Windows
• CPC Class Codes: H01J 37/3244 Gas supply means

Abstract

In a microwave plasma processing apparatus, a shower plate or plasma transmission window facing a substrate to be processed is formed to have a concaved surface at a side facing the substrate to be processes for compensating for a decrease of plasma density in the peripheral region of the substrate to be processed. As a result, stable and uniform plasma is maintained in the vicinity of the surface of the substrate to be processed even in the case a low pressure plasma process such as etching is conducted. Further, such a construction facilitates plasma ignition.

Claims

1. A plasma processing apparatus, characterized by:

a processing vessel defined by a wall and provided with a stage for holding a substrate to be processed;

a microwave transmission window provided on said processing vessel so as to face said substrate to be processed on said stage, said microwave transmission window being provided as a part of said wall of said processing vessel;

a plasma gas supplying part supplying a plasma gas into said processing vessel; and

a microwave antenna provided on said processing vessel in correspondence to said microwave,

said microwave transmission window having a concaved inner surface at a side facing said substrate to be processed, such that a separation between said inner surface and a plane coincident to a surface of said substrate to be processed decreases in a radially outward direction of said microwave transmission window.

2. The plasma processing apparatus as claimed in claim 1, characterized in that said separation decreases continuously in a radially outward direction of said microwave transmission window.

3. The plasma processing apparatus as claimed in claim 2, characterized in that said separation decreases smoothly in said radially outward direction of said microwave transmission window.

4. The plasma processing apparatus as claimed in claim 2, characterized in that said separation decreases linearly in said radially outward direction of said microwave transmission window.

5. The plasma processing apparatus as claimed in claim 2, characterized in that said separation decreases in a non-linear relationship in said radially outward direction of said microwave transmission window.

6. The plasma processing apparatus as claimed in claim 1, characterized in that said separation decreases stepwise in said radially outward direction of said microwave transmission window.

7. The plasma processing apparatus as claimed in claim 1, characterized in that said separation is decreased in said radially outward direction of said microwave transmission widow exclusively in a peripheral part of said microwave transmission window.

8. The plasma processing apparatus as claimed in claim 1, characterized in that said microwave transmission window has a flat surface at an outer surface thereof opposing said inner surface.

9. The plasma processing apparatus as claimed in claim 1, characterized in that said microwave transmission window includes a plasma gas passage therein, said microwave transmission window constituting said plasma gas supplying part and releasing said plasma gas into said processing vessel.

10. The plasma processing apparatus as claimed in claim 9, characterized in that said microwave window includes a plurality of apertures communicating with said plasma gas passage.

11. The plasma processing apparatus as claimed in claim 10, characterized in that said microwave transmission window comprises a cover plate forming a part of said wall of said processing vessel, and a shower plate provided in intimate contact with said cover plate and having a plurality of apertures communicating with said plasma gas passage.

12. The plasma processing apparatus as claimed in claim 10, characterized in that said microwave transmission window comprises a dense ceramic.

13. The plasma processing apparatus as claimed in claim 9, characterized in that said microwave plasma processing window is formed of a porous medium.

14. The plasma processing apparatus as claimed in claim 9, characterized in that said microwave transmission window comprises a cover plate constituting a part of said processing vessel and a shower plate of a porous medium provided in intimate contact with said cover plate.

15. The plasma processing apparatus as claimed in claim 13, characterized in that said porous medium is formed of a sintered ceramic.

16. The plasma processing apparatus as claimed in claim 1, characterized in that said plasma gas supplying part comprises a tube formed in said wall of said processing vessel so as to be connectable to a plasma gas source.

17. The plasma processing apparatus as claimed in claim 16, characterized in that said microwave transmission window comprises a dense ceramic.

18. The plasma processing apparatus as claimed in claim 1, further characterized by a process gas supplying part between said substrate to be processed and said plasma gas source.

19. The plasma processing apparatus as claimed in claim 18, characterized in that said process gas supplying part comprises a plasma passage causing to pas plasma, a process gas supplying passage connectable to a process gas source;

and a large number of nozzle apertures communicating with said process gas passage.

20. The plasma processing apparatus as claimed in claim 1, further characterized by a high-frequency source connected to said stage.

21. The plasma processing apparatus as claimed in claim 1, characterized in that said microwave antenna comprises a radial line slot antenna.