Toroidal low-field reactive gas source

• US 7,161,112 B2
• Filed: 10/20/2003
• Issued: 01/09/2007
• Est. Priority Date: 06/26/1997
• Status: Expired due to Fees

• Current Assignee: MKS Instruments Incorporated
• Original Assignee: MKS Instruments Incorporated
• Inventors: Smith, Donald K., Holber, William M., Georgelis, Eric, Chen, Xing
• Primary Examiner(s): PASCHALL, MARK H
• Application Number:
  US10/689,165
• Publication Number:
  US 20040079287A1
• Time in Patent Office: 1,177 Days
• Field of Search: 219/121.43, 219/121.41, 219/121.4, 219/121.57, 219/121.52, 219/121.54, 315/111.51, 156/345.44, 156/345.47, 156/345.48
• US Class Current: 219/121.57
• CPC Class Codes: H01J 27/16 using high-frequency excitation, e.g. microwave excitation
• CPC Class Codes: H01J 37/32009 Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources plasma generation in general H05H1/24
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream
• CPC Class Codes: H01J 37/32862 In situ cleaning of vessels and/or internal parts

Abstract

An apparatus for dissociating gases includes a plasma chamber that may be formed from a metallic material and a transformer having a magnetic core surrounding a portion of the plasma chamber and having a primary winding. The apparatus also includes one or more switching semiconductor devices that are directly coupled to a voltage supply and that have an output coupled to the primary winding of the transformer. The one or more switching semiconductor devices drive current in the primary winding that induces a potential inside the chamber that forms a plasma which completes a secondary circuit of the transformer.

Claims

1. A toroidal plasma chamber for use with a reactive gas source comprising:

an inlet for receiving a gas;

at least one plasma chamber wall for containing the gas, the plasma chamber wall comprising at least one of a metallic material or coated metallic material;

at least one dielectric spacer that electrically isolates the plasma chamber into a plurality of portions to prevent induced current flow from forming in the plasma chamber itself, the dielectric spacer being protected from a plasma formed in the plasma chamber by at least one plasma chamber wall; and

an outlet for outputting a reactive gas generated by the interaction of the plasma and the gas.

2. A toroidal plasma chamber for use with a reactive gas source comprising:

an inlet for receiving a gas;

one or more chamber walls for containing the gas, the chamber walls comprising at least one of a metallic material, coated metallic material or dielectric material and capable of receiving at least one dielectric spacer that electrically isolates a region of the plasma chamber to prevent induced current flow from forming in the plasma chamber itself, one or more of said plasma chamber walls capable of protecting the at least one dielectric spacer from a plasma formed in the plasma chamber; and

an outlet for outputting a reactive gas generated by the interaction of the plasma and the gas.

3. The plasma chamber of claim 2 further comprising the at least one dielectric spacer.

4. The plasma chamber of claim 2 wherein the dielectric spacer is protected from the plasma by a protrusion in at least one plasma chamber wall.

5. The plasma chamber of claim 2 wherein the dielectric spacer is protected from the plasma by at least one protruded plasma chamber wall.

6. The plasma chamber of claim 5 wherein the dielectric spacer is disposed in a recess adjacent the at least one protruded plasma chamber wall.

7. The plasma chamber of claim 2 further comprising a vacuum seal disposed adjacent the dielectric spacer.

8. The plasma chamber of claim 3 wherein the dielectric spacer is protected from the plasma by a protrusion in one or more of said plasma chamber walls.

9. The plasma chamber of claim 3 wherein the dielectric spacer is protected from the plasma by at least one or more protruded plasma chamber walls.

10. The plasma chamber of claim 3 wherein the dielectric spacer is disposed in a recess adjacent the at least one or more protruded plasma chamber walls.

11. The plasma chamber of claim 3 further comprising a vacuum seal disposed adjacent the dielectric spacer.