PLASMA PROCESSING SYSTEM WITH DIRECT OUTLET TOROIDAL PLASMA SOURCE

• US 20160163513A1
• Filed: 12/09/2014
• Published: 06/09/2016
• Est. Priority Date: 12/09/2014
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Lubomirsky, Dmitry
• Granted Patent: US 10,224,210 B2
• Time in Patent Office: Days
• 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 37/32449 Gas control, e.g. control of the gas flow
• CPC Class Codes: H01J 37/32458 Vessel
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching

Abstract

A plasma processing system includes a process chamber and a plasma source that generates a plasma in a plasma cavity. The plasma cavity is substantially symmetric about a toroidal axis. The plasma source defines a plurality of outlet apertures on a first axial side of the plasma cavity Plasma products produced by the plasma pass in the axial direction, through the plurality of outlet apertures, from the plasma cavity toward the process chamber. A method of plasma processing includes generating a plasma within a substantially toroidal plasma cavity that defines a toroidal axis, to form plasma products, and distributing the plasma products to a process chamber through a plurality of outlet openings substantially azimuthally distributed about a first axial side of the plasma cavity, directly into a process chamber.

Claims

1. A plasma processing system, comprising:

a process chamber; and

a plasma source that generates a plasma in a plasma cavity,

the plasma cavity being substantially radially symmetric about a toroidal axis,

the plasma source defining a plurality of outlet apertures on a first axial side of the plasma cavity, wherein plasma products produced by the plasma pass in the axial direction, through the plurality of outlet apertures, from the plasma cavity toward the process chamber.

2. The plasma processing system of claim 1, wherein the plasma source comprises a plasma generation block and a planar plate adjoining the plasma generation block on the first axial side, the plasma generation block and the planar plate substantially enclosing the plasma cavity, the planar plate defining the plurality of outlet apertures.

3. The plasma processing system of claim 2, the plasma source further comprising an induction coil and a magnetic core element,

the induction coil winding at least partially about the magnetic core element, and

the magnetic core element being disposed adjacent to the plasma generation block,

such that a current in the induction coil induces a magnetic flux in the magnetic core element, and the magnetic flux in the magnetic core element induces an azimuthal electric current within the plasma cavity to generate the plasma.

4. The plasma processing system of claim 3, the planar plate comprising a dielectric material, the plasma cavity comprising aluminum and including a plurality of dielectric breaks that interrupt azimuthal currents induced by the magnetic flux.

5. The plasma processing system of claim 1, the process chamber being substantially radially symmetric about the toroidal axis, the plurality of outlet apertures being arranged symmetrically with respect to the toroidal axis such that the plasma products are distributed uniformly, across the radial direction, from the plasma cavity toward the process chamber.

6. The plasma processing system of claim 1, further comprising gas inlets that mix un-activated gases with the plasma products before the plasma products enter the process chamber.

7. The plasma processing system of claim 1, further comprising a diffuser plate defining a plurality of apertures therethrough, disposed between the plasma source and the process chamber.

8. The plasma processing system of claim 7, the diffuser plate defining one or more gas passages that conduct un-activated gases to a side of the diffuser plate that faces the process chamber.

9. A plasma processing system, comprising:

a process chamber that is substantially radially symmetric about a chamber axis;

an outer plasma source that generates a first plasma in an outer plasma cavity,

the outer plasma cavity being radially symmetric about a toroidal axis that is coincident with the chamber axis,

the outer plasma cavity being in fluid communication with the process chamber through an outer outlet opening along a first axial side of the outer plasma source, such that plasma products produced by the first plasma pass in the axial direction, through the outer outlet opening, from the outer plasma cavity toward the process chamber; and

an inner plasma source that generates a second plasma in an inner plasma cavity,

the inner plasma cavity being radially symmetric about the toroidal axis that is coincident with the chamber axis, and being radially inward from the outer plasma cavity,

the inner plasma cavity being in fluid communication with the process chamber through an inner outlet opening along a first axial side of the inner plasma source, such that plasma products produced by the second plasma pass in the axial direction, through the inner outlet opening, from the inner plasma cavity toward the process chamber.

10. The plasma processing system of claim 9, wherein at least one of the outer outlet opening and the inner outlet opening are substantially azimuthally continuous.

11. The plasma processing system of claim 9, wherein the inner outlet opening and the outer outlet opening are defined in an outer plate of the plasma chamber, the processing system further comprising a diffuser plate disposed between the outer plate and a processing location within the plasma chamber.

12. The plasma processing system of claim 11, further comprising a circular domain separator that is disposed radially between the inner plasma source and the outer plasma source, the domain separator being in continuous contact with both the outer plate of the plasma chamber and the diffuser plate about a circumference of the domain separator.

13. The plasma processing system of claim 9, wherein source gas supplies to the inner and outer plasma sources are independently controllable to adjust process effects occurring at a center region and an edge region of the process chamber.

14. A method of plasma processing, comprising:

generating a plasma within a substantially toroidal plasma cavity that defines a toroidal axis, to form plasma products; and

distributing the plasma products to a process chamber through a plurality of outlet openings substantially azimuthally distributed about a first axial side of the plasma cavity, directly into a process chamber.

15. The method of claim 14, further comprising:

introducing source gases into the plasma cavity; and

inducing an azimuthal electric field within the plasma cavity, to generate the plasma from the source gases.

16. The method of claim 15, wherein providing the azimuthal electric field comprises providing a current in an induction coil to induce a magnetic flux in a magnetic element disposed adjacent the plasma cavity, such that the magnetic flux in the magnetic core element induces the azimuthal electric field.

17. The method of claim 14, further comprising mixing one or more un-activated gases with the plasma products.

18. The method of claim 17, wherein mixing the one or more un-activated gases with the plasma products comprises passing the plasma products through apertures formed through a diffuser plate, and supplying the one or more un-activated gases through gas passages in the diffuser plate.