Smart multi-level RF pulsing methods

Patent metadata

Field	Value
Publication number	US-9872373-B1
Application number	US-201715415129-A
Country	US
Kind code	B1
Filing date	Jan 25, 2017
Priority date	Oct 25, 2016
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

Methods of operating a plasma enhanced substrate processing system using multi-level pulsed RF power are provided herein. In some embodiments, a method of operating a plasma enhanced substrate processing system using multi-level pulsed RF power includes providing a first multi-level RF power waveform to a process chamber, the first multi-level RF power waveform having at least a first power level, a second power level, and a third power level, providing, after a first delay period, a second multi-level RF power waveform to the process chamber, the second multi-level RF power waveform having at least a first power level, a second power level, and a third power level, and processing the substrate using the first multi-level RF power waveform and the second multi-level RF power waveform to produce a features on the substrate have an aspect ratio of greater than 60:1 while maintaining an etch rate of greater than 170 nm/min.

First claim

The invention claimed is:

1. A method for processing a substrate in a plasma enhanced substrate processing system using multi-level pulsed RF power, comprising:
providing, from a first RF generator, a first multi-level RF power waveform to a process chamber, the first multi-level RF power waveform having at least a first power level during a first pulse duration, a second power level during a second pulse duration, and a third power level during a third pulse duration, wherein the first, second and third power levels of the first multi-level RF power waveform are different from each other;
providing, from a second RF generator and_after a first delay period, a second multi-level RF power waveform to the process chamber, the second multi-level RF power waveform having at least a first power level during a first pulse duration, a second power level during a second pulse duration, and a third power level during a third pulse duration, wherein the first, second and third power levels of the second multi-level RF power waveform are different from each other; and
processing the substrate using the first multi-level RF power waveform and the second multi-level RF power waveform to produce features on the substrate having an aspect ratio of greater than 60:1 while maintaining an etch rate of greater than 170 nm/min.

2. The method of claim 1 , wherein the features produced on the substrate have an aspect ratio of greater than 60:1 while maintaining an etch rate of at least 240 nm/min.

3. The method of claim 1 , wherein the first power level of the first multi-level RF power waveform is a high power level, the second power level of the first multi-level RF power waveform is a low power level that is lower than the first power level of the first multi-level RF power waveform, and the third power level of the first multi-level RF power waveform is a zero power level.

4. The method of claim 3 , wherein the first power level of the second multi-level RF power waveform is a high power level, the second power level of the second multi-level RF power waveform is a low power level that is lower than the first power level of the second multi-level RF power waveform, and the third power level of the second multi-level RF power waveform is a zero power level.

5. The method of claim 1 , further comprising:
providing, from a third RF generator and after a second delay period, a third multi-level RF power waveform to the process chamber, the third multi-level RF power waveform having at least a first power level during a first pulse duration and a second power level during a second pulse duration, wherein the first, second and third power levels of the third multi-level RF power waveform are different from each other.

6. The method of claim 5 , wherein the first multi-level RF power waveform and the third multi-level RF power waveform are synchronized.

7. The method of claim 5 , wherein the first multi-level RF power waveform, the second multi-level RF power waveform are synchronized, and the third multi-level RF power waveform are synchronized.

8. The method of claim 5 , wherein one of the first, second and third power levels of each of the first, second, and third multi-level RF power waveforms is a zero power level.

9. The method of claim 5 , wherein a duration of time that each of the first, second and third power levels of the first multi-level RF power waveform are applied are different from each other.

10. The method of claim 5 , wherein a duration of time that each of the first, second and third power levels of the second multi-level RF power waveform are applied are different from each other.

11. The method of claim 5 , wherein a duration of time that each of the first, second and third power levels of the third multi-level RF power waveform are applied are different from each other.

12. The method of claim 5 , wherein first multi-level RF power waveform is a source RF signal, and the second and third multi-level RF power waveforms are RF bias signals.

13. The method of claim 1 , wherein the substrate is processed using a Reactive Ion Etch (RIE) process.

14. The method of claim 1 , wherein processing the substrate using the multi-level pulsed RF power produces a mask selectivity of greater than 5:1.

15. The method of claim 1 , wherein processing the substrate using the multi-level pulsed RF power produces reduced profile bowing effects having a delta CD less than 20 nm.

16. A non-transitory computer readable medium having instructions stored thereon that, when executed, cause a method of operating a plasma enhanced substrate processing system using multi-level pulsed RF power to be performed, the method comprising:
providing, from a first RF generator, a first multi-level RF power waveform to a process chamber, the first multi-level RF power waveform having at least a first power level during a first pulse duration, a second power level during a second pulse duration, and a third power level during a third pulse duration, wherein the first, second and third power levels of the first multi-level RF power waveform are different from each other;
providing, from a second RF generator and after a first delay period, a second multi-level RF power waveform to the process chamber, the second multi-level RF power waveform having at least a first power level during a first pulse duration, a second power level during a second pulse duration, and a third power level during a third pulse duration, wherein the first, second and third power levels of the second multi-level RF power waveform are different from each other; and
processing the substrate using the first multi-level RF power waveform and the second multi-level RF power waveform to produce feature on the substrate having an aspect ratio of greater than 60:1 while maintaining an etch rate of greater than 170 nm/min.

17. A method for processing a substrate in a plasma enhanced substrate processing system using multi-level pulsed RF power, comprising:
providing, from a first RF generator, a first multi-level RF power waveform to a process chamber, the first multi-level RF power waveform having at least a first power level during a first pulse duration, a second power level during a second pulse duration, and a third power level during a third pulse duration, wherein the first, second and third power levels of the first multi-level RF power waveform are different from each other;
providing, from a second RF generator and after a first delay period, a second multi-level RF power waveform to the process chamber, the second multi-level RF power waveform having at least a first power level during a first pulse duration, a second power level during a second pulse duration, and a third power level during a third pulse duration, wherein the first, second and third power levels of the second multi-level RF power waveform are different from each other;
providing, from a third RF generator and after a second delay period, a third multi-level RF power waveform to the process chamber, the third multi-level RF power waveform having at least a first power level during a first pulse duration and a second power level during a second pulse duration, wherein the first, second and third power levels of the third multi-level RF power waveform are different from each other; and
processing the substrate using the first multi-level RF power waveform and the second multi-level RF power waveform to produce features on the substrate having an aspect ratio of greater than 60:1 while maintaining an etch rate of greater than 170 nm/min, wherein processing the substrate using the multi-

Assignees

• Applied Materials Inc

Inventors

• Shimizu Daisuke
• Lee Wonseok
• Kawasaki Katsumasa
• Ling Li
• Phi Justin
• Choi Kevin

Classifications

• H05H1/46 Primary

  using applied electromagnetic fields, e.g. high frequency or microwave energy (H05H1/26 takes precedence) · CPC title

• H05H2001/4645

  Electricity · mapped topic

• H01J37/32128

  using particular waveforms, e.g. polarised waves · CPC title

• H05H1/4645

  Radiofrequency discharges · CPC title

• H01J37/32146

  Amplitude modulation, includes pulsing · CPC title