Method and system for controlling radical distribution

• US 20070068625A1
• Filed: 09/23/2005
• Published: 03/29/2007
• Est. Priority Date: 09/23/2005
• Status: Active Grant

• Current Assignee: International Business Machines Corporation, Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Chen, Lee, Funk, Merritt, Horak, David, Strang, Eric
• Granted Patent: US 7,718,030 B2
• Time in Patent Office: Days
• US Class Current: 156/345.290
• CPC Class Codes: C23C 16/4412 Details relating to the exhausts, e.g. pumps, filters, scrubbers, particle traps
• CPC Class Codes: C23C 16/45565 Shower nozzles
• 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: H01J 37/32834 Exhausting

Abstract

A plasma processing system includes a processing chamber, a substrate holder configured to hold a substrate for plasma processing, and a gas injection assembly. The gas injection assembly includes a first evacuation port located substantially in a center of the gas injection assembly and configured to evacuate gases from a central region of the substrate, and a gas injection system configured to inject gases in the process chamber. The plasma processing system also includes a second evacuation port configured to evacuate gases from a peripheral region surrounding the central region of the substrate.

Claims

1. A plasma processing system comprising:

a processing chamber;

a substrate holder configured to hold a substrate for plasma processing;

a gas injection assembly comprising;

a first evacuation port located substantially in a center of the gas injection assembly and configured to evacuate gases from a central region of the substrate, and

a gas injection system configured to inject gases in said process chamber; and

a second evacuation port configured to evacuate gases from a peripheral region surrounding said central region of the substrate.

2. The system of claim 1, wherein said gas injection system comprises at least two zones configured to inject gases, the at least two zones being arranged concentrically around the center of the gas injection assembly.

3. The system of claim 2, wherein said at least two zones comprise holes in a surface of the gas injection assembly facing the substrate holder configured to inject the gases, said holes being substantially equally distributed over the surface of the gas injection assembly facing the substrate holder.

4. The system of claim 1, wherein said first evacuation port further comprises:

an exhaust duct having an entrant region located substantially in the center of the gas injection assembly; and

a pump coupled to said exhaust duct, and configured to evacuate gases through said entrant region.

5. The system of claim 1, wherein said gas evacuation port further comprises:

at least two holes arranged substantially concentrically around a center of the gas injection assembly; and

a pump coupled to said at least two holes, and configured to evacuate gases through said at least two holes.

6. The system of claim 4, wherein said pump is a turbomolecular pump.

7. The system of claim 4, further comprising a baffle plate configured to separate the first evacuation port from an interior of said chamber.

8. The system of claim 7, wherein said baffle plate comprises openings configured to allow gas to pass from said interior to the pump, while impeding the plasma from passing from said interior to the pump.

9. The system of claim 8, wherein said openings are tapered, a wider opening of the holes being arranged to face said interior.

10. The system of claim 4, wherein the entrant region has a diameter between 1 cm and 15 cm.

11. The system of claim 8, wherein the baffle plate is mounted on a lower surface of the gas injection assembly.

12. The system of claim 8, wherein the baffle plate is an integral part of the gas injection assembly.

13. The system of claim 1, wherein said second evacuation port comprises a sidewall port coupled to said processing chamber.

14. The system of claim 1, wherein said second evacuation port comprises a peripheral evacuation port on said gas injection assembly and radially spaced from said first evacuation port.

15. A plasma processing system comprising:

a processing chamber configured to contain a plasma therein;

a substrate holder configured to hold a substrate for plasma processing;

means for injecting process gas into said processing chamber;

means for evacuating a central region of said processing chamber; and

means for evacuating a peripheral region of said processing chamber.

16. The system of claim 15, further comprising means for retaining said plasma within said process chamber.

17. A method of controlling the pressure in a plasma processing chamber, comprising:

evacuating the gases from a peripheral region of a processing region proximate to a substrate being processed in said plasma processing chamber;

evacuating the gases substantially from a center of said processing region through an evacuation port in a gas injection assembly located above said substrate; and

controlling said evacuating the gases using at least one of a pump or a valve.