Plasma source pumping and gas injection baffle

• US 8,747,610 B2
• Filed: 03/30/2012
• Issued: 06/10/2014
• Est. Priority Date: 03/30/2012
• Status: Expired due to Fees

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Chen, Lee, Funk, Merritt
• Primary Examiner(s): Vinh, Lan
• Application Number:
  US13/436,760
• Publication Number:
  US 20130256268A1
• Time in Patent Office: 802 Days
• Field of Search: 156/345.3, 156/345.33, 156/345.38, 156/345.39, 156/345.34, 438/706, 438/714, 438/729, 438/731
• US Class Current: 156/345.39
• CPC Class Codes: H01J 37/32504 Means for preventing sputtering of the vessel
• CPC Class Codes: H01J 37/32633 Baffles
• CPC Class Codes: H01J 37/32834 Exhausting
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge

Abstract

A plasma processing system. The processing system comprises a process chamber having first and second ends arranged such that the first end opposes the second end. A substrate support is positioned at the first end of the process chamber and is configured to support a substrate. An exhaust system is positioned proximate the second end of the process chamber and draws a vacuum on the process chamber. Between the exhaust system and substrate support there is a plurality of super-Debye openings, and between the exhaust system and the plurality of super-Debye openings is a plurality of sub-Debye openings. The super-Debye openings are configured to limit diffusion of plasma while the sub-Debye openings are configured to quench plasma.

Claims

1. A plasma processing system comprising:

a process chamber having first and second ends, the first end opposing the second end;

a substrate support configured to support a substrate thereon, the substrate support being positioned at the first end of the process chamber;

an exhaust system configured to draw a vacuum and operably coupled proximate the second end of the process chamber;

a plurality of super-Debye openings positioned between the exhaust system and the substrate support and configured to limit diffusion of a plasma therethrough; and

a plurality of sub-Debye openings positioned between the exhaust system and the plurality of super-Debye openings and configured to quench the diffusing plasma.

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

a process gas supply fluidically coupled to the process chamber and configured to inject at least one process gas therein.

3. The plasma processing system of claim 2, wherein the process gas supply further comprises:

a plurality of nozzles configured to disperse the at least one process gas between the plurality of super-Debye openings and the substrate.

4. The plasma processing system of claim 3, wherein each of the plurality of nozzles extends through a respective one of the plurality of super-Debye openings.

5. The plasma processing system of claim 1, wherein the plurality of super-Debye openings is positioned within a first baffle plate and the plurality of sub-Debye openings is positioned within a second baffle plate.

6. The plasma processing system of claim 5, wherein the first and second baffle plates are electrically floating, electrically grounded, or referenced to an RF, DC, or AC reference potential.

7. The plasma processing system of claim 1, wherein the plurality of super-Debye openings is positioned within a plurality of baffle plates.

8. The plasma processing system of claim 1, wherein the plurality of sub-Debye openings is positioned within a plurality of baffle plates.

9. The plasma processing system of claim 1, wherein the pluralities of super-Debye openings and sub-Debye openings are optimized to maximize gas transmission through the super-Debye openings and the sub-Debye openings of the pluralities.

10. The plasma processing system of claim 1, wherein the exhaust system includes a turbo pump positioned on an opposite side of the plurality of super-Debye openings and the plurality of sub-Debye openings from the substrate for drawing the vacuum without engaging the plasma.

11. The plasma processing system of claim 1, wherein the plurality of sub-Debye openings are included within a mesh-like material.

12. A plasma processing system comprising:

a process chamber;

a substrate positioned within the process chamber and having a processing surface;

a substrate support configured to support the substrate thereon such that the processing surface opposes the substrate support and faces a process space;

an exhaust system positioned such that the process space is between the processing surface of the substrate and the exhaust system, the exhaust system configured to draw a vacuum on the process space;

a plurality of super-Debye openings positioned between the exhaust system and the processing surface of the substrate and configured to limit diffusion of a plasma from the process space toward the exhaust system; and

a plurality of sub-Debye openings positioned between the exhaust system and the plurality of super-Debye openings and configured to quench a quiescent plasma diffusing from the plurality of super-Debye openings toward the exhaust system.

13. The plasma processing system of claim 12, further comprising:

a process gas supply fluidically coupled to the process chamber and configured to supply at least one process gas into the process space above the processing surface of the substrate; and

a plurality of nozzles configured to disperse the at least one process gas between the plurality of super-Debye openings and the substrate.

14. The plasma processing system of claim 13, wherein each of the plurality of nozzles extends through a respective one of the plurality of super-Debye openings.

15. The plasma processing system of claim 12, wherein the plurality of super-Debye openings are positioned within a first baffle plate and the plurality of sub-Debye openings are positioned within a second baffle plate.

16. The plasma processing system of claim 12, wherein the plurality of sub-Debye openings are included within a mesh-like material.

17. A method of operating a plasma processing system having a process chamber and configured to process a substrate, the method comprising:

positioning the substrate on a substrate holder within the process chamber such that a processing surface of the substrate faces a process space within the process chamber, the process space configured to contain a plasma therein;

injecting a process gas into the process space through a first plate for igniting the plasma, the first plate having a plurality of super-Debye openings therein, wherein a diameter of each of the plurality of super-Debye openings is greater than one Debye length of the plasma;

igniting the plasma from the process gas within the process space; and

operating a vacuum pump to exhaust the process gas and the plasma from the process space, through the first plate having the super-Debye openings therein, through a second plate having a plurality of sub-Debye openings therein, wherein a diameter of each of the plurality of sub-Debye openings is no greater than one Debye length of the plasma, and thereafter to the vacuum pump.

18. The method of claim 17, wherein the process gas is dispersed within a manifold before injecting through the first plate.

19. A plasma processing system comprising:

a process chamber having first and second ends, the first end opposing the second end;

a substrate support configured to support a substrate thereon, the substrate being positioned at the first end of the process chamber;

a gas supply having a gas injection port fluidically coupled with the process chamber and configured to inject a process gas into the process chamber;

a plurality of super-Debye openings positioned between the gas injection port and the substrate support and configured to permit transmission of process gas to the process chamber and to limit diffusion of a plasma from the process chamber to the gas injection port; and

a plurality of sub-Debye openings positioned between the gas injection port and the plurality of super-Debye openings and configured to quench a quiescent plasma.

20. A plasma processing system comprising:

a process chamber having first and second ends, the first end opposing the second end;

a substrate support configured to support a substrate thereon, the substrate support being positioned at the first end of the process chamber;

a sensor operably coupled to the process chamber and configured to detect at least one process parameter within the process chamber;

a plurality of super-Debye openings positioned between the sensor and the substrate support and configured to limit diffusion of a plasma from the process chamber to the sensor; and

a plurality of sub-Debye openings positioned between the sensor and the plurality of super-Debye openings and configured to quench a quiescent plasma.