Inductively coupled plasma source with symmetrical RF feed

Patent metadata

Field	Value
Publication number	US-9928987-B2
Application number	US-201313897592-A
Country	US
Kind code	B2
Filing date	May 20, 2013
Priority date	Jul 20, 2012
Publication date	Mar 27, 2018
Grant date	Mar 27, 2018

Abstract

A plasma reactor has an overhead multiple coil inductive plasma source with RF feeds arranged in equilateral symmetry.

First claim

What is claimed is:

1. A plasma reactor comprising:
a window assembly;
inner, middle and outer current distributors, respectively, wherein each of said current distributors comprises top and bottom circular edges and a circularly continuous surface extending between respective top and bottom circular edges with successive current distributors being nested, and wherein each of the middle and outer current distributors includes a plurality of radially extending azimuthally separated portions extending outward from respective circularly continuous surface and a plurality of axial legs extending from said plurality of radially extending azimuthally separated portions;
inner, middle and outer coil antennas adjacent said window assembly, said inner, middle and outer coil antennas each comprising plural parallel conductors having a set of conductor ends, wherein said conductor ends of said inner coil antenna are connected to the bottom circular edge of said inner current distributor, and respective conductor ends of said middle and outer coil antennas are connected to respective plurality of axial legs of said middle and outer current distributors;
a ceiling plate overlying said window assembly and first, second and third RF power terminals at said ceiling plate;
first, second and third axial RF power feeds connected between respective ones of said first, second and third RF power terminals and respective ones of said inner, middle and outer current distributors;
wherein said first and second axial RF power feeds comprise first and second axial RF connection rods respectively, and said third axial RF power feed comprises said circularly continuous surface of said outer current distributor surrounding said first and second RF connection rods.

2. The plasma reactor of claim 1 further comprising a ground plate below said ceiling plate and above said middle current distributor, said plural axial legs of said middle current distributor extending through said ground plate.

3. The plasma reactor of claim 2 wherein said plural axial legs of said outer current distributor extend through said ground plate.

4. The plasma reactor of claim 1 further comprising:
plural spaced-apart reactance elements connected to said circularly continuous surface of said outer current distributor.

5. The plasma reactor of claim 4 wherein said reactance elements are coupled in parallel between said circularly continuous surface of said outer current distributor and said ceiling plate.

6. The plasma reactor of claim 5 wherein said reactance elements comprise discrete capacitors.

7. The plasma reactor of claim 4 wherein said reactance elements are uniformly spaced about a periphery of said circularly continuous surface of said outer current distributor.

8. The plasma reactor of claim 1 wherein said third axial RF power feed further comprises a top conductor coupled to said circularly continuous surface of said outer current distributor.

9. The plasma reactor of claim 8 wherein:
said top conductor comprises an upper axial section aligned with said third RF power terminal, a lower axial section coupled to said circularly continuous surface of said outer current distributor, and a radial section connected between said upper and lower axial sections.

10. The plasma reactor of claim 9 wherein said second axial RF connection rod comprises a lower axial rod section coupled to said circularly continuous surface of said middle current distributor, an upper axial rod section aligned with said second RF power terminal, and a radial rod section connected between said upper and lower axial rod sections.

11. The plasma reactor of claim 10 wherein said first axial RF connection rod comprises a lower axial connection section coupled to said circularly continuous surface of said inner current distributor, an upper axial connection section aligned with said first RF power terminal, and an intermediate radial connection section connected between said upper and lower axial connection sections.

12. The plasma reactor of claim 11 wherein said lower axial section of said top conductor, said lower axial rod section of said second axial RF connection rod, and said lower axial connection section of said first axial RF connection rod extend above said top circular edge of said circularly continuous surface of said outer current distributor.

13. The plasma reactor of claim 12 wherein said lower axial section of said top conductor, said lower axial rod section of said second axial RF connection rod, and said lower axial connection section of said first axial RF connection rod are located equilaterally with respect to each other.

14. The plasma reactor of claim 1 wherein said outer coil antenna comprises a cylindrical side coil and wherein said window assembly comprises a disk-shaped window facing at least one of said inner and middle coil antennas and a cylindrical side window facing said cylindrical side coil.

15. The plasma reactor of claim 1 further comprising:
a plenum plate spaced from and below said ceiling plate and comprising a central opening.

16. The plasma reactor of claim 15 wherein said circularly continuous surface of said outer current distributor extends through said central opening.

Assignees

• Applied Materials Inc

Inventors

• Kenney Jason A
• Carducci James D
• Collins Kenneth S
• Fovell Richard
• Ramaswamy Kartik
• Rauf Shahid

Classifications

• H01J37/04 Primary

  Arrangements of electrodes and associated parts for generating or controlling the discharge, e.g. electron-optical arrangement or ion-optical arrangement {(H01J37/32009, H01J37/32623, H01J37/3266, H01J37/32697 take precedence; electron or ion-optical systems for localised treatment of objects H01J37/3007)} · CPC title

• H05H1/46 Primary

  using applied electromagnetic fields, e.g. high frequency or microwave energy (H05H1/26 takes precedence) · CPC title

• H01J37/3211

  Antennas, e.g. particular shapes of coils · CPC title

• H01J37/321

  the radio frequency energy being inductively coupled to the plasma · CPC title

• H05H2001/4667

  Electricity · mapped topic