Symmetrical inductively coupled plasma source with symmetrical flow chamber

Patent metadata

Field	Value
Publication number	US-9745663-B2
Application number	US-201213666224-A
Country	US
Kind code	B2
Filing date	Nov 1, 2012
Priority date	Jul 20, 2012
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

A plasma reactor has an overhead multiple coil inductive plasma source with symmetric RF feeds and a symmetrical chamber exhaust with plural struts through the exhaust region providing access to a confined workpiece support. A grid may be included for masking spatial effects of the struts from the processing region.

First claim

What is claimed is:

1. A plasma reactor comprising:
a lid assembly, an axially symmetric side wall and a workpiece support defining a processing region;
a first coil antenna facing said lid assembly and a second coil antenna facing one of: (a) said side wall and (b) said lid assembly, said first and second coil antennas being coaxial with said side wall, wherein said first and second coil antennas are of different diameters;
plural RF power sources and plural current distributors coupled between respective ones of said first and second coil antennas and respective ones of said plural RF power sources, each of said current distributors comprising: (A) a hollow circular conductor coaxial with said side wall and defining a circularly continuous surface extending between top and bottom circular edges, (B) a top cap receiving portion extending radially inwardly from said top circular edge and coupled to a respective one of said plural RF power sources, said bottom circular edge coupled to the respective one of said coil antennas, and (C) an RF power feed, wherein respective ones of said current distributors and top cap receiving portions are of respective diameters corresponding to said different diameters of said first and second coil antennas with the current distributor of a greater diameter surrounding the current distributor and top cap receiving portion of a lesser diameter, and wherein the top cap receiving portion of at least one of the plural current distributors includes a plurality of radially extending azimuthally separated portions extending outward to connect the RF power feed of the respective current distributor to the hollow circular conductor of the respective current distributor;
a chamber body defining an evacuation region and a central space sealed from said processing region and from said evacuation region, said central space enveloping at least a portion of said workpiece support;
plural exhaust passages extending in an axial direction and coupled to said processing region and said evacuation region; and
a vacuum pump port coupled to said evacuation region and centered relative to said side wall.

2. The plasma reactor of claim 1 further comprising a lift mechanism fixed with respect to said chamber body and coupled to said workpiece support, said workpiece support being movable in said axial direction.

3. The plasma reactor of claim 1 further comprising plural hollow access struts extending radially through said chamber body to said central space and respective utility lines extending through respective ones of said plural hollow access struts.

4. The plasma reactor of claim 3 wherein said plural exhaust passages are distributed symmetrically with respect to an axis of symmetry and are located between adjacent ones of said plural hollow access struts.

5. The plasma reactor of claim 1 further comprising a chamber body liner extending radially from a wall of said chamber body to a containment wall, said chamber body liner comprising a gas flow grid disposed between said processing region and said plural hollow access struts.

6. The plasma reactor of claim 5 wherein said gas flow grid comprises an annular array of elongate openings each extending along a radial direction.

7. The plasma reactor of claim 1 wherein said second coil antenna faces said lid assembly, said plasma reactor further comprising a third coil antenna encircling said side wall.

8. The plasma reactor of claim 1 wherein each one of said coil antennas comprises plural conductors helically wound about an axis of symmetry, each of said plural conductors having a supply end and a ground end, a first circular edge of the respective one of said plural current distributors connected to said supply ends of the respective coil antenna at spaced-apart locations along said first circular edge.

9. The plasma reactor of claim 8 wherein said spaced-apart locations are uniformly distributed.

10. The plasma reactor of claim 8 further comprising an RF feed rod assembly coupled to a respective one of said RF power sources and arranged uniformly with respect to an axis of symmetry of said side wall, and connected to said receiving portion of said respective current distributor.

11. The plasma reactor of claim 1 wherein:
said lid assembly comprises a disk-shaped dielectric window, and said side wall comprises a cylindrical dielectric window;
said plasma reactor further comprising:
respective separately controlled heater layers on respective ones of said dielectric windows;
a first set of air fans directed along a first air flow path across said disk-shaped dielectric window;
a second set of air fans directed along a second air flow path across said cylindrical dielectric window;
a controller independently controlling said respective heater layers and said first and second sets of air fans.

12. A plasma reactor comprising:
an axially symmetrical enclosure and a workpiece support, said workpiece support and said enclosure defining a processing region;
plural concentric coil antennas disposed on an external side of said enclosure and being coaxial with said enclosure, wherein said coil antennas are of different diameters;
plural RF power sources and plural current distributors coupled between respective ones of said coil antennas and respective ones of said plural RF power sources, each of said current distributors comprising a hollow circular conductor coaxial with said side wall and defining a circularly continuous surface extending between top and bottom circular edges, and having a receiving portion coupled to a respective one of said plural RF power sources, said bottom circular edge coupled to the respective one of said coil antennas, respective ones of said current distributors being of respective diameters corresponding to said different diameters of said coil antennas, the current distributor of a greater diameter surrounding the current distributor and receiving portion of a lesser diameter, and wherein at least one of the plural current distributors includes a plurality of radially extending azimuthally separated portions extending outward to connect the receiving portion of the respective current distributor to the hollow circular conductor of the respective current distributor;
a chamber body defining an exhaust region and confining a portion of said workpiece support in a sealed central space surrounded by said exhaust region, said chamber body having a vacuum pump port coaxial with said enclosure; and
plural hollow access struts extending radially through said chamber body to said central region.

13. The plasma reactor of claim 12 further comprising a gas flow grid extending radially through said exhaust region and located between said processing region and said access struts.

14. The plasma reactor of claim 13 wherein said gas flow grid comprises an annular array of elongate openings each extending a radial direction.

15. The plasma reactor of claim 12 further comprising a lift mechanism fixed with respect to said chamber body and coupled to said workpiece support, said workpiece support being movable in an axial direction.

16. The plasma reactor of claim 12 further comprising respective utility lines extending through respective ones of said plural hollow access struts.

17. The plasma reactor of claim 12 wherein said plural hollow access struts divide a portion of said exhaust region into plural axial exhaust passages distributed symmetrically with respect to an axis of symmetry.

18. The plasma reactor of claim 17 further comprising a chamber body liner com

Assignees

• Applied Materials Inc

Inventors

• Nguyen Andrew
• Collins Kenneth S
• Ramaswamy Kartik
• Rauf Shahid
• Carducci James D
• Buchberger Jr Douglas A
• Agarwal Ankur
• Kenney Jason A
• Dorf Leonid
• Balakrishna Ajit
• Fovell Richard

Classifications

• B01J12/002

  carried out in the plasma state (generating or handling plasma H05H1/00) · CPC title

• H01J37/32733

  Means for moving the material to be treated · CPC title

• C23C14/28

  by wave energy or particle radiation (C23C14/32 - C23C14/48 take precedence) · CPC title

• H01J37/32834

  Exhausting · CPC title

• C23F1/08 Primary

  Apparatus, e.g. for photomechanical printing surfaces (photo- mechanical reproduction G03F) · CPC title