Plasma Tuning Rods in Microwave Processing Systems

• US 20130081762A1
• Filed: 09/30/2011
• Published: 04/04/2013
• Est. Priority Date: 09/30/2011
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Zhao, Jianping, Chen, Lee, Funk, Merritt, Ventzek, Peter L.G., Iwao, Toshihiko
• Granted Patent: US 8,808,496 B2
• Time in Patent Office: Days
• US Class Current: 156/345.34
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32247 Resonators
• CPC Class Codes: H01J 37/32256 Tuning means
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

The invention provides a plurality of plasma tuning rod subsystems. The plasma tuning rod subsystems can comprise one or more microwave cavities configured to couple electromagnetic (EM) energy in a desired EM wave mode to a plasma by generating resonant microwave energy in one or more plasma tuning rods within and/or adjacent to the plasma. One or more microwave cavity assemblies can be coupled to a process chamber, and can comprise one or more tuning spaces/cavities. Each tuning space/cavity can have one or more plasma tuning rods coupled thereto. Some of the plasma tuning rods can be configured to couple the EM energy from one or more of the resonant cavities to the process space within the process chamber and thereby create uniform plasma within the process space.

Claims

1. A microwave processing system for processing a substrate comprising:

a rectangular process chamber comprising a process space having a movable substrate holder therein;

a first cavity assembly coupled to the rectangular process chamber using a first interface assembly, the first cavity assembly having a first electromagnetic (EM) energy tuning space therein, the first interface assembly including a first set of isolation assemblies, wherein a first set of EM-coupling regions, are established in a first EM energy tuning space;

a first set of plasma-tuning rods coupled to the first set of isolation assemblies, the first set of plasma-tuning rods having a first set of plasma-tuning portions configured in the process space and a first set of EM-tuning portions configured in the first EM energy tuning space and coupled to at least one of the first set of EM-coupling regions;

a second cavity assembly coupled to the rectangular process chamber using a second interface assembly, the second cavity assembly having a second EM energy tuning space therein, the second interface assembly including a second set of isolation assemblies, wherein a second set of EM-coupling regions are established in the second EM energy tuning space;

a second set of plasma-tuning rods coupled to the second set of isolation assemblies, the second set of plasma-tuning rods having a second set of plasma-tuning portions configured in the process space and a second set of EM-tuning portions configured in the second EM energy tuning space and coupled to at least one of the second set of EM-coupling regions; and

a controller coupled to the first cavity assembly and the second cavity assembly, wherein the controller is configured to control the first set of EM-coupling regions in the first EM energy tuning space and the second set of EM-coupling regions in the second EM energy tuning space, thereby controlling plasma uniformity in the process space.

2. The microwave processing system of claim 1, further comprising:

a first coupling network coupled to the first cavity assembly;

a first matching network coupled to the first coupling network;

a first EM source coupled to the first matching network, wherein the first EM source is configured to operate in a frequency range from 500 MHz to 5000 MHz;

wherein the controller is coupled to the first EM source and configured to control the first EM source, thereby controlling the plasma uniformity in the process space;

a second coupling network coupled to the second cavity assembly;

a second matching network coupled to the second coupling network;

a second EM source coupled to the second matching network, wherein the second EM source is configured to operate in a second frequency range from 500 MHz to 5000 MHz);

wherein the controller is coupled to the second EM source and configured to control the second EM source, thereby controlling the plasma uniformity in the process space.

3. The microwave processing system of claim 1, further comprising:

a first plasma-tuning slab configured proximate to the first EM-coupling region in the first EM energy tuning space;

a first control assembly coupled to the first plasma-tuning slab through a first cavity assembly wall, the first plasma-tuning slab being positioned at a first EM-coupling distance from the first EM-tuning portion by the first control assembly;

wherein the controller is coupled to the first control assembly and is configured to control the first plasma-tuning distance, thereby controlling the plasma uniformity in the process space;

a second plasma-tuning slab configured proximate to the second EM-coupling region in the second EM energy tuning space;

a second control assembly coupled to the second plasma-tuning slab through a second cavity assembly wall, the second plasma-tuning slab being positioned at a second EM-coupling distance from the second EM-tuning portion by the second control assembly;

wherein the controller is coupled to the second control assembly and is configured to control the second plasma-tuning distance, thereby controlling the plasma uniformity in the process space.

4. The microwave processing system of claim 1, wherein the first set of plasma-tuning rods, the first cavity assembly, the second set of plasma-tuning rods, and the second cavity assembly comprise dielectric material.

5. The microwave processing system of claim 1, further comprising:

a gas showerhead coupled to the rectangular process chamber;

a gas supply subassembly coupled to the gas showerhead; and

a gas supply system coupled to the gas supply subassembly, wherein the gas showerhead is configured to introduce a process gas to the process space, wherein the controller is coupled to the gas supply system, to the gas supply subassembly, and to the gas showerhead and is configured to control the gas supply system, the gas supply subassembly, and the gas showerhead, thereby controlling the plasma uniformity in the process space.

6. The microwave processing system of claim 5, wherein the process gas comprises two or more of:

C₄F₈, C₈F₈, C₃F₆, C₄F₆, CF₄, CHF₃, CH₂F₂, an inert gas, oxygen, CO, and CO₂.

7. The microwave processing system of claim 5, wherein the process gas comprises two or more of:

HBr, Cl₂, NF₃, SF₆, CHF₃, CH₂F₂, an inert gas, oxygen, CO, and CO₂.

8. The microwave processing system of claim 1, further comprising:

a first cavity-tuning slab configured proximate to a first end of the first EM energy tuning space in the first cavity assembly;

a first cavity-control assembly coupled to the first cavity-tuning slab, wherein the first cavity-tuning slab is positioned at a first cavity-tuning distance from at least one wall of the first cavity assembly, wherein the controller is coupled to the first cavity-control assembly and is configured to control the first cavity-tuning distance, thereby controlling the plasma uniformity in the process space;

a second cavity-tuning slab configured proximate to the first end of the second EM energy tuning space in the second cavity assembly; and

a second cavity-control assembly coupled to the second cavity-tuning slab, wherein the second cavity-tuning slab is positioned at a second cavity-tuning distance from at least one wall of the second cavity assembly, wherein the controller is coupled to the second cavity-control assembly and is configured to control the second cavity-tuning distance, thereby controlling the plasma uniformity in the process space.

9. The microwave processing system of claim 8, wherein the first cavity-tuning slab, the first cavity-control assembly, the second cavity-tuning slab, and the second cavity-control assembly comprise dielectric material. (I can'"'"'t find support for dielectric material in spec)

10. A microwave processing system for processing a substrate comprising:

a process chamber comprising a process space having a movable substrate holder therein;

a first cavity assembly coupled to the process chamber using a first interface assembly, the first cavity assembly having a first electromagnetic (EM) energy tuning space therein, the first interface assembly including a first isolation assembly, wherein a first pair of EM-coupling regions are established in a first EM energy tuning space;

a first pair of plasma-tuning rods coupled to the first isolation assembly, the first pair of plasma-tuning rods having plasma-tuning portions configured in the process space and having EM-tuning portions configured in the first EM energy tuning space, wherein a first EM-tuning portion is coupled to a first EM-coupling region and a second EM-tuning portion is coupled to a second EM-coupling region;

a second cavity assembly coupled to the process chamber using a second interface assembly, the second cavity assembly having a second EM energy tuning space therein, the second interface assembly including a second isolation assembly, wherein a second pair of EM-coupling regions are established in the second EM energy tuning space;

a second pair of plasma-tuning rods coupled to the second isolation assembly, the second pair of plasma-tuning rods having second plasma-tuning portions configured in the process space and having second EM-tuning portions configured in the second EM energy tuning space, wherein a third EM-tuning portion is coupled to a third EM-coupling region, and a fourth EM-tuning portion is coupled to a fourth EM-coupling region; and

a controller coupled to the first cavity assembly and the second cavity assembly, wherein the controller is configured to control the first pair of EM-coupling regions in the first EM energy tuning space and the second pair of EM-coupling regions in the second EM energy tuning space, thereby controlling plasma uniformity in the process space.

11. The microwave processing system of claim 10, further comprising:

a first coupling network coupled to the first cavity assembly;

a first matching network coupled to the first coupling network;

a first EM source coupled to the first matching network, wherein the first EM source is configured to operate in a frequency range from 500 MHz to 5000 MHz, wherein the controller is coupled to the first EM source and configured to control the first EM source, thereby controlling the plasma uniformity in the process space;

a second coupling network coupled to the second cavity assembly;

a second matching network coupled to the second coupling network; and

a second EM source coupled to the second matching network, wherein the second EM source is configured to operate in a second frequency range from 500 MHz to 5000 MHz, wherein the controller is coupled to the second EM source and configured to control the second EM source, thereby controlling the plasma uniformity in the process space.

12. The microwave processing system of claim 10, further comprising:

a first pair of plasma-tuning slabs configured proximate to the first EM-coupling region in the first EM energy tuning space;

a first pair of control assemblies coupled to the first pair of plasma-tuning slabs through a first cavity assembly wall, a first plasma-tuning slab being positioned at a first EM-coupling distance from the first EM-tuning portion by a first control assembly;

a second plasma-tuning slab being positioned at a second EM-coupling distance from the second EM-tuning portion by a second control assembly, wherein the controller is coupled to the first control assembly and the second control assembly, the controller being configured to control the first EM-coupling distance and the second EM-coupling distance, thereby controlling the plasma uniformity in the process space;

a second pair of plasma-tuning slabs configured proximate to the second EM-coupling region in the second EM energy tuning space;

a second pair of control assemblies coupled to the second pair of plasma-tuning slabs through a second cavity assembly wall, a third plasma-tuning slab being positioned at a third EM-coupling distance from the third EM-tuning portion by a third control assembly; and

a fourth plasma-tuning slab being positioned at a fourth EM-coupling distance from the fourth EM-tuning portion by a fourth control assembly, wherein the controller is coupled to the first control assembly and the second control assembly, the controller being configured to control the third EM-coupling distance and the fourth EM-coupling distance, thereby controlling the plasma uniformity in the process space.

13. The microwave processing system of claim 10, further comprising:

a gas showerhead coupled to the process chamber;

a gas supply subassembly coupled to the gas showerhead; and

a gas supply system coupled to the gas supply subassembly, wherein the gas showerhead is configured to introduce a process gas to the process space, wherein the controller is coupled to the gas supply system, to the gas supply subassembly, and to the gas showerhead and is configured to control the gas supply system, the gas supply subassembly, and the gas showerhead, thereby controlling the plasma uniformity in the process space.

14. A method of processing a substrate using a microwave processing system comprising:

positioning a substrate on a movable substrate holder within a process space in a rectangular process chamber;

coupling a first cavity assembly to the rectangular process chamber using a first interface assembly, the first cavity assembly having a first EM energy tuning space therein, the first interface assembly including a first set of isolation assemblies, wherein a first set of EM-coupling regions are established in the first EM energy tuning space;

coupling a first set of plasma-tuning rods to the first set of isolation assemblies, the first set of plasma-tuning rods having a first set of plasma-tuning portions configured in the process space and a first set of EM-tuning portions configured in the first EM energy tuning space and coupled to at least one of the first set of EM-coupling regions;

coupling a second cavity assembly to the rectangular process chamber using a second interface assembly, the second cavity assembly having a second EM energy tuning space therein, the second interface assembly including a second set of isolation assemblies, wherein a second set of EM-coupling regions are established in the second EM energy tuning space;

coupling a second set of plasma-tuning rods to the second set of isolation assemblies, the second set of plasma-tuning rods having a second set of plasma-tuning portions configured in the process space and a second set of EM-tuning portions configured in the second EM energy tuning space and coupled to at least one of the second set of EM-coupling regions; and

coupling a controller to the first cavity assembly and the second cavity assembly, wherein the controller is configured to control the first set of EM-coupling coupling regions in the first EM energy tuning space and the second set of EM-coupling regions in the second EM energy tuning space, thereby controlling plasma uniformity in the process space.

15. The method of claim 14, further comprising:

coupling a first coupling network to the first cavity assembly;

coupling a first matching network to the first coupling network;

coupling a first EM source to the first matching network, wherein the first EM source is configured to operate in a frequency range from 500 MHz to 5000 MHz, wherein the controller is coupled to the first EM source and configured to control the first EM source, thereby controlling the plasma uniformity in the process space;

coupling a second coupling network to the second cavity assembly;

coupling a second matching network to the second coupling network; and

coupling a second EM source to the second matching network, wherein the second EM source is configured to operate in a second frequency range from 500 MHz to 5000 MHz, wherein the controller is coupled to the second EM source and configured to control the second EM source, thereby controlling the plasma uniformity in the process space.

16. The method of claim 14, further comprising:

coupling the first cavity assembly to the rectangular process chamber using the first interface assembly, the first cavity assembly having the first electromagnetic (EM) energy tuning space therein, the first interface assembly including the first set of isolation assemblies, wherein the first set of EM-coupling regions are established in the first EM energy tuning space;

coupling the first set of plasma-tuning rods to the first set of isolation assemblies, the first set of plasma-tuning rods having the first set of plasma-tuning portions configured in the process space and the first set of EM-tuning portions configured in the first EM energy tuning space and coupled to at least one of the first set of EM-coupling regions;

coupling the second cavity assembly to the rectangular process chamber using the second interface assembly, the second cavity assembly having the second EM energy tuning space therein, the second interface assembly including the second set of isolation assemblies, wherein the second set of EM-coupling regions are established in the second EM energy tuning space;

coupling the second set of plasma-tuning rods to the second set of isolation assemblies, the second set of plasma-tuning rods having the second set of plasma-tuning portions configured in the process space and the second set of EM-tuning portions configured in the second EM energy tuning space and coupled to at least one of the second set of EM-coupling regions; and

controlling the first set of EM-coupling coupling regions in the first EM energy tuning space and controlling the second set of EM-coupling regions in the second EM energy tuning space, thereby controlling the plasma uniformity in the process space, wherein the controller is coupled to the first cavity assembly and to the second cavity assembly.

17. The method of claim 14, further comprising:

coupling a gas showerhead to the rectangular process chamber;

coupling a gas supply subassembly to the gas showerhead; and

coupling a gas supply system to the gas supply subassembly, wherein the gas showerhead is configured to introduce a process gas to the process space, wherein the controller is coupled to the gas supply system, to the gas supply subassembly, and to the gas showerhead and is configured to control the gas supply system, the gas supply subassembly, and the gas showerhead, thereby controlling the plasma uniformity in the process space.

18. The method of claim 17, wherein the process gas comprises two or more of:

C₄F₈, C₅F₈, C₃F₆, C₄F₆, CF₄, CHF₃, CH₂F₂, an inert gas, oxygen, CO, and CO₂.

19. The method of claim 17, wherein the process gas comprises two or more of:

HBr, Cl₂, NF₃, SF₆, CHF₃, CH₂F₂, an inert gas, oxygen, CO, and CO₂.

20. The method of claim 14, further comprising:

positioning a first cavity-tuning slab proximate to a first end of the first EM energy tuning space in the first cavity assembly;

coupling a first cavity-control assembly to the first cavity-tuning slab, wherein the first cavity-tuning slab is positioned at a first cavity-tuning distance from at least one wall of the first cavity assembly, wherein the controller is coupled to the first cavity-control assembly and is configured to control the first cavity-tuning distance, thereby controlling the plasma uniformity in the process space;

positioning a second cavity-tuning slab proximate to a second end of the second EM energy tuning space in the second cavity assembly; and

coupling a second cavity-control assembly to the second cavity-tuning slab, wherein the second cavity-tuning slab is positioned at a second cavity-tuning distance from at least one wall of the second cavity assembly, wherein the controller is coupled to the second cavity-control assembly and is configured to control the second cavity-tuning distance, thereby controlling the plasma uniformity in the process space.