Guided wave applicator with non-gaseous dielectric for plasma chamber

• US 9,397,380 B2
• Filed: 01/27/2012
• Issued: 07/19/2016
• Est. Priority Date: 01/28/2011
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Kudela, Jozef, Tanaka, Tsutomu, Sorensen, Carl A., Anwar, Suhail, White, John M.
• Primary Examiner(s): Hendricks, Keith
• Assistant Examiner(s): Raphael, Colleen M
• Application Number:
  US13/360,652
• Publication Number:
  US 20130126331A1
• Time in Patent Office: 1,635 Days
• Field of Search: 204/157.15, 118/723.MW, 333/239, 156/345.41
• US Class Current: 1/1
• CPC Class Codes: H01J 37/32229 Waveguides
• CPC Class Codes: H01L 21/02 Manufacture or treatment of semiconductor devices or of parts thereof
• CPC Class Codes: H01L 21/02104 Forming layers deposition in general C23C; crystal growth in general C30B
• CPC Class Codes: H01P 3/16 Dielectric waveguides, i.e. without a longitudinal conductor
• CPC Class Codes: H05H 1/46 using applied electromagnetic fields, e.g. high frequency or microwave energy H05H1/26 takes precedence
• CPC Class Codes: H05H 1/4622 using waveguides

Abstract

A guided wave applicator comprising two electrically conductive waveguide walls and a waveguide dielectric. The volume of the waveguide dielectric is composed of non-gaseous dielectric material and is positioned between the two waveguide walls. The waveguide dielectric includes first and second longitudinal ends and includes first, second, third and fourth sides extending longitudinally between the two longitudinal ends. The first waveguide wall is positioned so that it covers the first side of the waveguide dielectric, and the second waveguide wall is positioned so that it covers the second side of the waveguide dielectric. In operation, electrical power can be supplied to one or both longitudinal ends of the waveguide dielectric, whereby the power can be coupled to a plasma through the exposed sides of the waveguide dielectric.

Claims

1. A method for coupling electrical power to a plasma, comprising the steps of:

providing a plasma chamber having an interior;

providing first and second waveguide walls, wherein each waveguide wall is electrically conductive;

providing within the interior of the plasma chamber a waveguide dielectric whose volume is composed of non-gaseous dielectric material, wherein the waveguide dielectric includes;

(i) first and second longitudinal ends, and

(ii) first, second, third and fourth sides that extend longitudinally between the two longitudinal ends; and

coupling electrical power from an electrical generator to at least one of the longitudinal ends of the waveguide dielectric;

wherein;

the waveguide dielectric is positioned between the two waveguide walls;

the first waveguide wall is positioned so that it covers the first side of the waveguide dielectric;

the second waveguide wall is positioned so that it covers the second side of the waveguide dielectric; and

a portion of each of the third and fourth sides of the waveguide dielectric is not covered by the waveguide walls and is exposed to the interior of the plasma chamber.

2. The method of claim 1, wherein:

at least half the surface area of each of the third and fourth sides of the waveguide dielectric is not covered by the waveguide walls and is exposed to the interior of the plasma chamber.

3. The method of claim 1, wherein:

at least half the surface area of each of the third and fourth sides of the waveguide dielectric is not covered by any electrically conductive solid object and is exposed to the interior of the plasma chamber.

4. The method of claim 1, wherein:

the first and second longitudinal ends of the waveguide dielectric are opposite each other;

the first and second sides of the waveguide dielectric are opposite each other; and

the third and fourth sides of the waveguide dielectric are opposite each other.

5. The method of claim 1, wherein:

the third and fourth sides of the waveguide dielectric have a greater transverse width than the first and second sides of the waveguide dielectric.

6. The method of claim 1, wherein:

the waveguide dielectric is shaped as a parallelepiped.

7. The method of claim 1, wherein:

each of the first and second sides of the waveguide dielectric has a planar surface; and

the first waveguide wall and the second waveguide wall each has a planar surface that covers the first side and the second side, respectively, of the waveguide dielectric.

8. The method of claim 1, further comprising the step of:

coupling electrical power from an electrical generator to at least one of the longitudinal ends of the waveguide dielectric.

9. The method of claim 1, further comprising the step of:

coupling microwave power from a microwave generator to at least one of the longitudinal ends of the waveguide dielectric.

10. The method of claim 1, wherein:

the waveguide dielectric is composed of a solid dielectric material.

11. The method of claim 1, wherein:

the waveguide dielectric consists of a monolithic, non-segmented dielectric material.

12. The method of claim 1, wherein:

the waveguide dielectric comprises a plurality of segments of dielectric material that are not connected directly together and that are distributed along the longitudinal dimension of the guided wave applicator.

13. The method of claim 1, wherein:

the waveguide dielectric comprises a plurality of segments of dielectric material that are not connected directly together; and

the segments are separated by gaps that are sufficiently small so as to prevent the formation of a plasma within the gaps in response to said electrical power.

14. The method of claim 1, wherein:

the waveguide dielectric comprises a plurality of segments of dielectric material that are not connected directly together and that are distributed along the longitudinal dimension of the guided wave applicator;

each segment has a transverse cross-section in the shape of a trapezoid having first and second legs, a short base, and a long base parallel to the short base, wherein the two legs respectively extend between the short base and the long base at respective acute angles relative to the long base;

the short base of each successive segment faces in opposite directions; and

the segments are sufficiently close together that the first leg of each segment overlaps the second leg of an adjacent one of the segments.

15. The method of claim 1, wherein:

the waveguide dielectric comprises a plurality of segments of dielectric material that are not connected directly together and that are distributed along the longitudinal dimension of the guided wave applicator;

each segment has a transverse cross-section in the shape of a trapezoid having a short base and a long base; and

the short base of each successive segment is mechanically connected to an alternate one of the two waveguide walls.

16. The method of claim 1, further comprising the step of:

providing a process gas conduit within a first one of the waveguide walls;

wherein the first waveguide wall has a surface exposed to the interior of the plasma chamber; and

the process conduit has a longitudinal axis parallel to said surface of the first waveguide wall and is coupled to a plurality of gas outlets at said surface of the first waveguide wall.

17. The method of claim 1, further comprising:

providing a tongue-in-groove joint between the first waveguide wall and the first side of the waveguide dielectric;

wherein the tongue-in-groove joint permits relative movement between the waveguide dielectric and the first waveguide wall along a direction extending between the first and second longitudinal ends of the waveguide dielectric.

18. The method of claim 1, wherein:

the first waveguide wall includes a first flange and a second flange;

the first flange covers a portion of the third side of the waveguide dielectric adjacent to the first side of the waveguide dielectric;

the second flange covers a portion of the fourth side of the waveguide dielectric adjacent to the first side of the waveguide dielectric; and

the first and second flanges permit relative movement between the waveguide dielectric and the first waveguide wall.

19. A method for coupling electrical power to a plasma, comprising the steps of:

providing one or more guided wave applicators within a plasma chamber, wherein each guided wave applicator comprises;

(i) first and second waveguide walls, wherein each waveguide wall is electrically conductive, and

(ii) a waveguide dielectric whose volume is composed of non-gaseous dielectric material, wherein the waveguide dielectric is positioned between the two waveguide walls, and wherein the waveguide dielectric includes first and second longitudinal ends and first, second, third and fourth sides that extend longitudinally between the first and second longitudinal ends; and

coupling electrical power from an electrical generator to at least one of the longitudinal ends of the waveguide dielectric of each guided wave applicator;

wherein, for each respective guided wave applicator;

the first waveguide wall of said respective guided wave applicator is positioned so that it covers the first side of the waveguide dielectric of said respective guided wave applicator;

the second waveguide wall of said respective guided wave applicator is positioned so that it covers the second side of the waveguide dielectric of said respective guided wave applicator; and

a portion of each of the third and fourth sides of the waveguide dielectric of said respective guided wave applicator is not covered by the waveguide walls of said respective guided wave applicator.

20. The method of claim 19, wherein:

for each respective guided wave applicator, at least half the surface area of each of the third and fourth sides of the waveguide dielectric of said respective guided wave applicator is not covered by the waveguide walls of said respective guided wave applicator.

21. The method of claim 19, wherein:

said one or more guided wave applicators comprise a plurality of guided wave applicators; and

the guided wave applicators are positioned within the plasma chamber such that their respective longitudinal axes are mutually parallel and such that they are spaced apart along a dimension perpendicular to their respective longitudinal axes.

22. The method of claim 19, further comprising:

a first workpiece support for supporting a first workpiece at a first workpiece position within the plasma chamber; and

a second workpiece support for supporting a second workpiece at a second workpiece position within the plasma chamber;

wherein one of the one or more guided wave applicators is positioned midway between the first and second workpiece positions.

23. The method of claim 19, further comprising:

a first workpiece support for supporting a first workpiece at a first workpiece position within the plasma chamber; and

a second workpiece support for supporting a second workpiece at a second workpiece position within the plasma chamber;

wherein said one or more guided wave applicators are positioned within a geometric plane that is midway between the first and second workpiece positions.

24. The method of claim 19, further comprising the steps of:

performing plasma processing of a workpiece within the plasma chamber;

moving the one or more guided wave applicators during said plasma processing.

25. The method of claim 19, further comprising the steps of:

supporting a workpiece on a workpiece support within the plasma chamber; and

moving the workpiece support during plasma processing of the workpiece within the plasma chamber.

26. A method for coupling electrical power to a plasma, comprising the steps of:

providing a guided wave applicator that comprises (a) first and second waveguide walls, wherein each waveguide wall is electrically conductive, and (b) a waveguide dielectric whose volume is composed of non-gaseous dielectric material, wherein the waveguide dielectric includes;

(i) first and second longitudinal ends, and

(ii) first, second, third and fourth sides that extend longitudinally between the two longitudinal ends; and

coupling electrical power from an electrical generator to at least one of the longitudinal ends of the waveguide dielectric;

wherein;

the waveguide dielectric is positioned between the two waveguide walls;

the first waveguide wall is positioned so that it covers the first side of the waveguide dielectric;

the second waveguide wall is positioned so that it covers the second side of the waveguide dielectric; and

a portion of each of the third and fourth sides of the waveguide dielectric is not covered by the waveguide walls and is exposed to the exterior of the guided wave applicator.