Plasma reactor gas distribution plate having a path splitting manifold immersed within a showerhead

• US 20090159213A1
• Filed: 12/19/2007
• Published: 06/25/2009
• Est. Priority Date: 12/19/2007
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Rauf, Shahid, Bera, Kallol
• Application Number:
  US12/004,472
• Publication Number:
  US 20090159213A1
• Time in Patent Office: Days
• US Class Current: 156/345.340
• CPC Class Codes: H01J 37/3244 Gas supply means

Abstract

A showerhead of a plasma reactor has an internal plenum comprising a showerhead floor and a plurality of gas injection holes through the floor of the showerhead. A path splitting manifold is immersed inside the plenum and comprises a gas supply inlet, plural gas outlets, and a plurality of channels comprising plural paths of equal lengths between the inlet and respective ones of the plural outlets.

Claims

1. A gas distribution showerhead assembly for use in a plasma reactor, comprising:

(a) a showerhead having an internal plenum and comprising a showerhead floor and a plurality of gas injection holes through said floor of said showerhead;

(b) a path splitting manifold immersed inside said plenum and comprising;

(1) a gas supply inlet;

(2) plural gas outlets;

(3) a plurality of channels comprising plural paths between said inlet and respective ones of said plural outlets;

(c) an electrode underlying said floor of said showerhead, said electrode having plural axial holes in registration with said gas injection holes of said showerhead.

2. The apparatus of claim 1 wherein said paths are of equal lengths.

3. The apparatus of claim 1 wherein said plurality of channels comprises a hierarchy of channels recursively coupled at their midpoints to outputs other channels of said hierarchy.

4. The apparatus of claim 1 wherein said plural gas outlets of said path splitting manifold comprise openings oriented in at least one of (a) an axial direction, (b) a radially outward direction, (c) a radially inward direction.

5. The apparatus of claim 1 further comprising a temperature control plate between said showerhead and said electrode.

6. The apparatus of claim 1 wherein said plurality of channels are distributed in an azimuthally extending plane.

7. The apparatus of claim 5 wherein said plurality of channels comprise:

a first channel coupled at its midpoint to said inlet;

a pair of second channels each coupled at its midpoint to a respective end of said first channel;

two pairs of third channels, each one of said third channels coupled at its midpoint to a respective end of a corresponding one of said second channels;

said ends of said third channels coupled to respective ones of said plural outlets of said manifold.

8. The apparatus of claim 7 wherein said first, second and third channels comprise concentric arcs.

9. The apparatus of claim 8 wherein said manifold is circular and said plural outlets of said manifold are equally spaced relative to a circumference of said manifold.

10. The apparatus of claim 1 wherein said manifold and said showerhead are contained within respective concentric annular zones.

11. A gas distribution showerhead assembly for use in a plasma reactor, comprising:

(I) an inner gas distribution zone comprising;

(a) an inner annular showerhead;

(b) an inner path splitting manifold contained within said inner showerhead;

(c) an electrode underlying said inner gas distribution zone;

(II) an outer gas distribution zone comprising;

(a) an outer annular showerhead; and

(a) an outer path splitting manifold contained inside said outer annular showerhead;

(c) said electrode further underlying said outer gas distribution zone.

12. The apparatus of claim 11 wherein:

each one of said manifolds comprises;

(a) a gas supply inlet;

(b) plural gas outlets;

(c) a plurality of channels comprising plural paths of equal lengths between said inlet and respective ones of said plural outlets.

13. The apparatus of claim 12 wherein said plural outlets comprise openings oriented in one of (a) an axial direction, (b) a radially outward direction, (c) a radially inward direction.

14. The apparatus of claim 12 wherein:

each one of said showerheads comprises;

(a) a showerhead floor; and

(b) a plurality of gas injection holes extending axially through said floor of said showerhead; and

said electrode underlies the floor of each showerhead, said electrode having plural axial holes in registration with the plural gas injection holes of the showerheads.

15. The apparatus of claim 12 wherein said plurality of channels comprise:

a first channel coupled at its midpoint to said inlet;

a pair of second channels each coupled at its midpoint to a respective end of said first channel;

two pairs of third channels, each one of said third channels coupled at its midpoint to a respective end of a corresponding one of said second channels;

said ends of said third channels coupled to respective ones of said plural outlets of said manifold.

16. The apparatus of claim 15 wherein said first, second and third channels comprise concentric arcs.

17. The apparatus of claim 12 wherein said plurality of channels comprise a hierarchy of channels recursively coupled at their midpoints to outputs of other channels of said hierarchy.

18. The apparatus of claim 16 wherein said manifold is circular and said plural outlets of said manifold are equally spaced relative to a circumference of said manifold.

19. A plasma reactor, comprising:

(I) an inner gas distribution zone comprising;

(a) an inner annular showerhead comprising an interior plenum;

(b) an inner path splitting manifold contained inside said interior plenum of said inner annular showerhead;

(c) an electrode underlying said inner showerhead;

(II) an outer gas distribution zone comprising;

(a) an outer annular showerhead comprising an interior plenum;

(b) an outer path splitting manifold contained inside the interior plenum of said outer annular showerhead;

(c) said electrode further underlying said outer showerhead;

(III) plural gas sources and respective valves coupled between individual ones of said plural gas sources and respective ones of said inner and outer manifolds;

(IV) an RF source power generator coupled to said electrode.

20. The apparatus of claim 19 wherein:

each one of said manifolds comprises;

(a) a gas supply inlet;

(b) plural gas outlets;

(c) a plurality of channels comprising plural paths of equal lengths between said inlet and respective ones of said plural outlets.

21. The apparatus of claim 20 wherein:

each one of said showerheads comprises;

(a) a showerhead floor; and

(b) a plurality of gas injection holes extending axially through said floor of said showerhead; and

said electrode underlies the floor of each showerhead, said electrode having plural axial holes in registration with the plural gas injection holes of the showerheads.