Plasma tuning rods in microwave resonator plasma sources

• US 9,728,416 B2
• Filed: 03/15/2013
• Issued: 08/08/2017
• 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, Toshihiko, Iwao, Ventzek, Peter L. G.
• Primary Examiner(s): DHINGRA, RAKESH KUMAR
• Application Number:
  US13/842,532
• Publication Number:
  US 20130224961A1
• Time in Patent Office: 1,607 Days
• Field of Search: 15634541, 118723 MW
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32256 Tuning means
• CPC Class Codes: H01J 37/32311 Circuits specially adapted for controlling the microwave discharge
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/67069 for drying etching

Abstract

A resonator system is provided with one or more resonant cavities configured to couple electromagnetic (EM) energy in a desired EM wave mode to plasma by generating resonant microwave energy in a resonant cavity adjacent the plasma. The resonator system can be coupled to a process chamber using one or more interface and isolation assemblies, and each resonant cavity can have a plurality of plasma tuning rods coupled thereto. The plasma tuning rods can be configured to couple the EM-energy from the resonant cavities to the process space within the process chamber.

Claims

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

a process chamber comprising a process space for processing a substrate therein;

a first resonator assembly coupled to the process chamber using a first interface assembly, the first resonator assembly having an 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, each with EM energy therein, are established in the EM-energy tuning space;

a first set of plasma-tuning rods coupled to a respective one of the first set of isolation assemblies, the first set of plasma-tuning rods having first plasma-tuning portions configured to control plasma uniformity in the process space and first EM-tuning portions in the EM-energy tuning space, each of the first plasma-tuning portions coupled to a respective one of the first set of EM-coupling regions, wherein the first set of EM-tuning portions are configured to obtain EM energy from the first set of EM-coupling regions;

a first set of plasma-tuning slabs disposed proximate to the EM-coupling regions in the EM energy tuning space and a first set of slab control assemblies coupled to the first set of plasma-tuning slabs through a cavity assembly wall, each plasma-tuning slab being positioned a variable EM-coupling distance from the EM-tuning portion of a plasma-tuning rod of the first set by a respective slab control assembly of the first set with each plasma tuning slab and slab control assembly of the first set positioned immediately opposite a corresponding plasma tuning rod of the first set, each plasma tuning slab and slab control assembly of the first set are configured to tune the EM energy in a respective one of the EM-coupling regions of the first set due to the positioning of each plasma-tuning slab and slab control assembly for the respective one of the EM-coupling regions being positioned immediately opposite the corresponding plasma-tuning rod for the respective one of the EM-coupling regions so that the EM energy in at least one EM-coupling region of the first set differs from the EM energy in at least one other EM-coupling region of the first set when the respective EM-coupling distance for the at least one EM-coupling region differs from the respective EM-coupling distance of the at least one other EM-coupling region due to a movement of the slab control assembly and the plasma-tuning slab for the at least one EM-coupling region differing from a movement length of the slab control assembly and the plasma-tuning slab for the at least one other EM-coupling region;

a resonator sensor coupled to the EM-energy tuning space, the resonator sensor being configured to obtain resonator data; and

a controller coupled to the first set of isolation assemblies, the first set of slab control assemblies, and the resonator sensor, wherein the controller is configured to independently control each of the first set of plasma-tuning slabs using the first set of slab control assemblies so as to control the first EM-coupling distance to tune each EM energy associated with each of the EM-coupling regions of the first set, the first set of plasma-tuning rods using the first set of isolation assemblies and the resonator data, thereby controlling the first set of EM-coupling regions in the first EM-energy tuning space to tune the EM energy therein and the plasma uniformity in the process space.

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

a coupling network coupled to the first resonator assembly;

a matching network coupled to the coupling network;

a microwave source coupled to the matching network, wherein the microwave source is configured to operate in a frequency range from 500 MHz to 5000 MHz, wherein the controller is coupled to the microwave source, the matching network and the coupling network, the controller being configured to control the microwave source, the matching network and/or the coupling network, thereby controlling the first set of EM-coupling regions in the EM-energy tuning space and the plasma uniformity in the process space.

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

a plurality of flow elements coupled to the process chamber and configured to provide process gas to the process space;

a plurality of supply elements coupled to the flow elements; and

a gas supply system coupled to the supply elements, wherein the controller is coupled to the gas supply system, the controller being configured to control the gas supply system, thereby controlling the first set of EM-coupling regions in the EM-energy tuning space and the plasma uniformity in the process space.

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

a cavity-tuning slab configured in the first EM-energy tuning space in the first resonator assembly;

a first cavity-control assembly coupled to the cavity-tuning slab, wherein the cavity-tuning slab is positioned at a cavity-tuning distance from a wall of the first resonator assembly, wherein the controller is coupled to the first cavity-control assembly and is configured to control the cavity-tuning distance, thereby controlling the first set of EM-coupling regions in the EM-energy tuning space and the plasma uniformity in the process space.

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

a lower electrode configured within the substrate holder; and

a Radio Frequency (RF) generator coupled to the lower electrode, wherein the controller is coupled to the RF generator and is configured to control the RF generator, thereby controlling the first set of EM-coupling regions in the EM-energy tuning space and the plasma uniformity in the process space.

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

a process chamber comprising a process space for processing a substrate therein;

one or more resonator assemblies coupled to a top chamber wall of the process chamber, each having a first electromagnetic (EM)-energy tuning space therein;

a first set of EM-coupling regions, each with EM energy therein, are established in the first EM-energy tuning spaces and a first set of isolation assemblies coupled to the top chamber wall and configured to isolate the first EM-energy tuning spaces from the process space;

a first set of protection assemblies coupled to the first set of isolation assemblies and extending into the process space, the protection assemblies having isolated protection spaces therein;

a first set of plasma-tuning rods coupled to a respective one of the first set of isolation assemblies, the first set of plasma-tuning rods having first plasma-tuning portions configured in the isolated protection spaces and first EM-tuning portions in the first EM-energy tuning space, each of the first plasma-tuning portions coupled to a respective one of the first set of EM-coupling regions, wherein the first set of EM-tuning portions are configured to obtain EM energy from the first set of EM-coupling regions and to control plasma uniformity in the process space;

a first set of plasma-tuning slabs disposed proximate to the EM-coupling regions in the EM energy tuning space and a first set of slab control assemblies coupled to the first set of plasma-tuning slabs through a cavity assembly wall, each plasma-tuning slab being positioned a variable EM-coupling distance from the EM-tuning portion of a plasma-tuning rod of the first set by a respective slab control assembly of the first set with each plasma tuning slab and slab control assembly of the first set positioned immediately opposite a corresponding plasma tuning rod of the first set, each plasma tuning slab and slab control assembly of the first set are configured to tune the EM energy in a respective one of the EM-coupling regions of the first set due to the positioning of each plasma-tuning slab and slab control assembly for the respective one of the EM-coupling regions being positioned immediately opposite the corresponding plasma-tuning rod for the respective one of the EM-coupling regions so that the EM energy in at least one EM-coupling region of the first set differs from the EM energy in at least one other EM-coupling region of the first set when the respective EM-coupling distance for the at least one EM-coupling region differs from the respective EM-coupling distance of the at least one other EM-coupling region due to a movement of the slab-control assembly and the plasma-tuning slab for the at least one EM-coupling region differing from a movement of the slab control assembly and the plasma-tuning slab for the at least one other EM-coupling region;

resonator sensors coupled to the EM-energy tuning spaces, the resonator sensors being configured to obtain resonator data; and

a controller coupled to the first set of isolation assemblies, the first set of slab control assemblies, and the resonator sensors, wherein the controller is configured to independently control each of the first set of plasma-tuning slabs using the first set of slab control assemblies so as to control the first EM-coupling distance to tune each EM energy associated with each of the EM-coupling regions of the first set, the first set of plasma-tuning rods using the first set of isolation assemblies and the resonator data, thereby controlling the first set of EM-coupling regions in the first EM-energy tuning spaces to tune the EM energy therein and the plasma uniformity in the process space.

7. The microwave processing system of claim 6, further comprising:

one or more coupling networks coupled to the one or more resonator assemblies;

a matching network coupled to each of the one or more coupling networks;

a microwave source coupled to the matching network, wherein the microwave source is configured to operate in a frequency range from 500 MHz to 5000 MHz, wherein the controller is coupled to the microwave source, the matching network and the one or more coupling networks, the controller being configured to control the microwave source, the matching network and/or the coupling networks, thereby controlling the first set of EM-coupling regions in the first EM-energy tuning spaces and the plasma uniformity in the process space.

8. The microwave processing system of claim 6, further comprising:

a plurality of supply elements coupled to the process chamber and configured to provide process gas to the process space; and

a gas supply system coupled to the supply elements, wherein the controller is coupled to the gas supply system, the controller being configured to control the gas supply system, thereby controlling the first set of EM-coupling regions in the EM-energy tuning spaces and the plasma uniformity in the process space.

9. The microwave processing system of claim 6, further comprising:

a cavity-tuning slab configured in the first EM-energy tuning spaces in the one or more resonator assemblies;

a first cavity-control assembly coupled to the cavity-tuning slab, wherein the cavity-tuning slab is positioned at a cavity-tuning distance from a wall of the one or more resonator assemblies, wherein the controller is coupled to the first cavity-control assembly and is configured to control the cavity-tuning distance, thereby controlling the first set of EM-coupling regions in the EM-energy tuning spaces and the plasma uniformity in the process space.

10. The microwave processing system of claim 6, further comprising:

one or more resonator subassemblies coupled to a side chamber wall of the process chamber and each having a second EM-energy tuning space therein;

a second set of isolation assemblies coupled to the side chamber wall and configured to isolate the second EM-energy tuning spaces from the process space;

a second set of protection assemblies coupled to the second set of isolation assemblies and extending into the process space, the second set of protection assemblies having second isolated protection spaces therein; and

a second set of plasma-tuning rods coupled to the second set of isolation assemblies and having second plasma-tuning portions configured in the second isolated protection spaces and second EM-tuning portions configured in second EM-coupling regions within the second EM-energy tuning space.

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

one or more EM sources coupled to the one or more resonator subassemblies, wherein the EM sources are configured to operate at frequencies from about 500 MHz to about 5000 MHz, wherein the controller is coupled to the one or more EM sources, the controller being configured to control the EM sources, thereby controlling the second EM-coupling regions in the second EM-energy tuning spaces and the plasma uniformity in the process space.

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

a second set of control assemblies coupled to the one or more resonator subassemblies; and

a second set of plasma-tuning slabs coupled to the second set of control assemblies and configured proximate to the second set of EM-coupling regions in the second EM-energy tuning spaces, wherein the controller is coupled to the second set of control assemblies and is configured to control EM-tuning distances established between the second set of plasma-tuning slabs and the second EM-tuning portions of the second set of plasma-tuning rods within the second EM-energy tuning spaces, thereby controlling the second set of EM-coupling regions in the second EM-energy tuning spaces and the plasma uniformity in the process space.

13. The microwave processing system of claim 10, wherein the process chamber is cylindrical having a cylindrical side chamber wall, and wherein the second set of plasma-tuning rods extend radially into the process space within the second isolated protection spaces.

14. The microwave processing system of claim 13, further comprising a substrate holder adjacent a bottom chamber wall for positioning one or more substrates on a surface thereof in the process space, wherein the substrate holder is rotatably or vertically movable.

15. The microwave processing system of claim 6, further comprising a substrate holder adjacent a bottom chamber wall for positioning one or more substrates on a surface thereof in the process space, wherein the substrate holder is rotatably or vertically movable.

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

a process chamber comprising a process space for processing a substrate therein;

a first resonator assembly coupled to the process chamber using a first interface assembly, the first resonator assembly having an 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, each with EM energy therein, are established in the EM-energy tuning space;

a first set of plasma-tuning rods coupled to a respective one of the first set of isolation assemblies, the first set of plasma-tuning rods having first plasma-tuning portions configured to control plasma uniformity in the process space and first EM-tuning portions in the EM-energy tuning space, each of the first plasma-tuning portions coupled to a respective one of the first set of EM-coupling regions, wherein the first set of EM-tuning portions are configured to obtain EM energy from the first set of EM-coupling regions;

a first set of plasma-tuning slabs disposed proximate to the EM-coupling regions in the EM energy tuning space and a first set of slab control assemblies coupled to the first set of plasma-tuning slabs through a cavity assembly wall, each plasma-tuning slab being positioned a variable EM-coupling distance from the EM-tuning portion of a plasma-tuning rod of the first set by a respective slab control assembly of the first set with each plasma tuning slab of the first set positioned immediately opposite a corresponding plasma tuning rod of the first set, each plasma tuning slab of the first set is configured to tune the EM energy in a respective one of the EM-coupling regions of the first set due to the positioning of each plasma-tuning slab for the respective one of the EM-coupling regions being positioned immediately opposite the corresponding plasma-tuning rod for the respective one of the EM-coupling regions;

a resonator sensor coupled to the EM-energy tuning space, the resonator sensor being configured to obtain resonator data; and

a controller coupled to the first set of isolation assemblies, the first set of slab control assemblies, and the resonator sensor, wherein the controller is configured to independently control each of the first set of plasma-tuning slabs using the first set of slab control assemblies so as to control the first EM-coupling distance to tune each EM energy associated with each of the EM-coupling regions of the first set, the first set of plasma-tuning rods using the first set of isolation assemblies and the resonator data, thereby controlling the first set of EM-coupling regions in the first EM-energy tuning space to tune the EM energy therein and the plasma uniformity in the process space.

17. The microwave processing system of claim 16, further comprising:

a coupling network coupled to the first resonator assembly;

a matching network coupled to the coupling network;

a microwave source coupled to the matching network, wherein the microwave source is configured to operate in a frequency range from 500 MHz to 5000 MHz, wherein the controller is coupled to the microwave source, the matching network and the coupling network, the controller being configured to control the microwave source, the matching network and/or the coupling network, thereby controlling the first set of EM-coupling regions in the EM-energy tuning space and the plasma uniformity in the process space.

18. The microwave processing system of claim 16, further comprising:

a plurality of flow elements coupled to the process chamber and configured to provide process gas to the process space;

a plurality of supply elements coupled to the flow elements; and

a gas supply system coupled to the supply elements, wherein the controller is coupled to the gas supply system, the controller being configured to control the gas supply system, thereby controlling the first set of EM-coupling regions in the EM-energy tuning space and the plasma uniformity in the process space.

19. The microwave processing system of claim 16, further comprising:

a cavity-tuning slab configured in the first EM-energy tuning space in the first resonator assembly;

a first cavity-control assembly coupled to the cavity-tuning slab, wherein the cavity-tuning slab is positioned at a cavity-tuning distance from a wall of the first resonator assembly, wherein the controller is coupled to the first cavity-control assembly and is configured to control the cavity-tuning distance, thereby controlling the first set of EM-coupling regions in the EM-energy tuning space and the plasma uniformity in the process space.

20. The microwave processing system of claim 16, further comprising:

a lower electrode configured within the substrate holder; and

a Radio Frequency (RF) generator coupled to the lower electrode, wherein the controller is coupled to the RF generator and is configured to control the RF generator, thereby controlling the first set of EM-coupling regions in the EM-energy tuning space and the plasma uniformity in the process space.