Tailored Electron Energy Distribution Function by New Plasma Source: Hybrid Electron Beam and RF Plasma

• US 20200135431A1
• Filed: 10/25/2018
• Published: 04/30/2020
• Est. Priority Date: 10/25/2018
• Status: Active Application

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Chen, Zhiying, Ventzek, Peter, Ranjan, Alok
• Application Number:
  US16/170,119
• Publication Number:
  US 20200135431A1
• Time in Patent Office: Days
• CPC Class Codes: H01J 37/32146 Amplitude modulation, includes pulsing
• CPC Class Codes: H01J 37/32174 Circuits specially adapted for controlling the RF discharge
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream

Abstract

Embodiments of hybrid electron beam and RF plasma systems and methods are described. In an embodiment a method of using a hybrid electron beam and RF plasma system may include forming a first plasma of a first type in a first region of a wafer processing structure. Additionally, such a method may include forming a second plasma of a second type in a second region of the wafer processing structure, the second region of the wafer processing structure being coupled to the first region of the wafer processing structure, the second plasma being ignited independently of the first plasma, wherein an electron beam formed by the first plasma is configured to modulate one or more characteristics of the second plasma. This hybrid e-beam and RF plasma system provides a source to control electron energy distribution function.

Claims

1. A method for plasma processing of a substrate, comprising:

forming a first plasma of a first type in a first region of a wafer processing structure; and

forming a second plasma of a second type in a second region of the wafer processing structure, the second region of the wafer processing structure being coupled to the first region of the wafer processing structure, the second plasma being ignited independently of the first plasma;

wherein an electron beam formed by the first plasma is configured to modulate one or more characteristics of the second plasma.

2. The method of claim 1, further comprising igniting the second plasma with a radio frequency (RF) energy source.

3. The method of claim 1, further comprising at least partially maintaining the second plasma with a radio frequency (RF) energy source.

4. The method of claim 1, further comprising directing an electron beam from the first plasma into the second plasma to modulate the one or more characteristics of the second plasma.

5. The method of claim 4, further comprising directing the electron beam through a channel between the first region and the second region.

6. The method of claim 4, further comprising directing the electron beam through a plurality of channels between the first region and the second region.

7. The method of claim 4, wherein at least one of a size of the channel between the first region and the second region or a number of channels between the first region and the second region is variable.

8. The method of claim 1, further comprising electrically grounding at least one surface in the second region.

9. The method of claim 1, further comprising electrically floating an enclosure of the first region.

10. The method of claim 1, further comprising applying a negative electric potential to at least one surface in the first region.

11. The method of claim 1, wherein modulating the characteristics of the second plasma includes tuning an electron energy distribution in a portion of the second plasma proximate to a surface of the substrate.

12. A system for plasma processing of a substrate, comprising:

a wafer processing structure comprising;

a first region configured to form a first plasma of a first type; and

a second region coupled to the first region, the second region configured to form a second plasma of a second type, the second plasma being ignited independently of the first plasma;

wherein an electron beam formed by first plasma is configured to modulate one or more characteristics of the second plasma.

13. The system of claim 12, further comprising a radio frequency (RF) energy source configured to ignite the second plasma.

14. The system of claim 12, further comprising a radio frequency (RF) energy source configured to at least partially maintain the second plasma.

15. The system of claim 12, further comprising an electron source configured to ignite the first plasma for directing an electron beam from the first plasma into the second plasma to modulate the one or more characteristics of the second plasma.

16. The system of claim 15, further comprising a channel coupled between the first region and the second region and configured to direct the electron beam from the first region to the second region.

17. The system of claim 15, further comprising a plurality of channels coupled between the first region and the second region and configured to direct the electron beam from the first region to the second region.

18. The system of claim 15, wherein at least one of a size of the channel between the first region and the second region or a number of channels between the first region and the second region is variable.

19. The system of claim 12, further comprising an electrical ground connection configured to electrically ground at least one surface in the second region.

20. The system of claim 12, further comprising a negative electric potential source coupled to the first region and configured to apply a negative electric potential to at least one surface in the first region.

22. The system of claim 12, further comprising a controller configured to modulate tune an electron energy distribution in a portion of the second plasma proximate to a surface of the substrate by varying an intensity of the electron beam introduced from the first plasma to the second plasma.

23. A method for plasma processing of a substrate, comprising:

forming a first plasma of a first type in a first region of a wafer processing structure; and

forming a second plasma of a second type in a second region of the wafer processing structure, the second region of the wafer processing structure being coupled to the first region of the wafer processing structure, the second plasma being maintained by a combination of energy received from a radio frequency (RF) energy source and from an electron beam introduced from the first plasma to the second plasma;

wherein a ratio of energy from the electron beam formed by the first plasma and the energy received from the RF energy source is selectable to modulate one or more characteristics of the second plasma.