Method and system for plasma process

Patent metadata

Field	Value
Publication number	US-2025226179-A1
Application number	US-202418406783-A
Country	US
Kind code	A1
Filing date	Jan 8, 2024
Priority date	Jan 8, 2024
Publication date	Jul 10, 2025
Grant date	—

Abstract

A method for generating a bias voltage includes generating a radio frequency (RF) sinusoidal wave voltage, generating a DC square wave voltage, and forming a bias waveform by synchronizing the RF sinusoidal wave voltage and the DC square wave voltage. The method further includes providing the bias waveform to an electrode of a plasma processing system.

First claim

What is claimed is:

1 . A method for generating a bias voltage, the method comprising:
generating a radio frequency (RF) sinusoidal wave voltage; generating a DC square wave voltage; forming a bias waveform by synchronizing the RF sinusoidal wave voltage and the DC square wave voltage; and providing the bias waveform to a bottom electrode of a plasma processing system.

2 . The method of claim 1 , wherein the RF sinusoidal wave voltage and the DC square wave voltage have a same frequency.

3 . The method of claim 2 , wherein the same frequency is in a range of 50 kHz to 100 MHz.

4 . The method of claim 1 , wherein the RF sinusoidal wave voltage and the DC square wave voltage are synchronized at a same phase.

5 . The method of claim 1 , wherein the RF sinusoidal wave voltage and the DC square wave voltage are synchronized at different phases.

6 . The method of claim 1 , wherein the plasma processing system uses pulsed plasma processing.

7 . The method of claim 1 , wherein the plasma processing system uses continuous wave plasma processing.

8 . The method of claim 1 , wherein the bias waveform compensates surface charge on a substrate in the plasma processing system.

9 . A method for plasma processing, the method comprising:
generating a bias waveform voltage by synchronizing a pulsed DC voltage and an RF sinusoidal wave voltage at a single frequency; generating a plasma in a plasma processing chamber by providing source power to a top electrode of the plasma processing chamber and providing the bias waveform voltage to a bottom electrode of the plasma processing chamber; and controlling an ion energy distribution of the plasma with the bias waveform voltage.

10 . The method of claim 9 , wherein controlling the ion energy distribution of the plasma with the bias waveform voltage comprises adjusting an amplitude of the pulsed DC voltage.

11 . The method of claim 10 , wherein adjusting the amplitude of the pulsed DC voltage controls a location of a peak energy of the ion energy distribution.

12 . The method of claim 9 , wherein controlling the ion energy distribution of the plasma with the bias waveform voltage comprises adjusting an amplitude of the RF sinusoidal wave voltage.

13 . The method of claim 12 , wherein adjusting the amplitude of the RF sinusoidal wave voltage controls a width of an ion energy spread of the ion energy distribution.

14 . The method of claim 9 , wherein controlling the ion energy distribution of the plasma with the bias waveform voltage comprises adjusting duty cycles of the RF sinusoidal wave voltage and the pulsed DC voltage.

15 . The method of claim 14 , wherein adjusting the duty cycles of the RF sinusoidal wave voltage and the pulsed DC voltage controls an ion flux of the ion energy distribution.

16 . The method of claim 8 , wherein the bias waveform voltage comprises sinusoidal horizontal segments between vertical segments in a graph of voltage versus time.

17 . A method for plasma processing, the method comprising:
providing a substrate into a plasma processing chamber; generating a plasma in the plasma processing chamber by providing source power to a top electrode of the plasma processing chamber; biasing a bottom electrode of the plasma processing chamber by providing pulsed DC voltage to the bottom electrode; and compensating surface charge on the substrate by providing RF sinusoidal wave voltage to the bottom electrode, the pulsed DC voltage and the RF sinusoidal wave voltage having a shared frequency.

18 . The method of claim 17 , wherein the shared frequency of the pulsed DC voltage and the RF sinusoidal wave voltage is in a range of 50 kHz to 100 MHz.

19 . The method of claim 17 , wherein the pulsed DC voltage is modulated to set a peak ion energy for an ion energy distribution of the plasma.

20 . The method of claim 17 , wherein, while the pulsed DC voltage is on, a voltage of the substrate is kept constant by the RF sinusoidal wave voltage.

Assignees

• Tokyo Electron Ltd

Inventors

• Chen Zhiying
• Wang Qiang
• Sridhar Shyam
• Blakeney Joel
• Carruth Megan
• Ventzek Peter Lowell George
• Ohata Mitsunori

Classifications

• H01J37/32422

  Arrangement for selecting ions or species in the plasma · CPC title

• H01J37/32174

  Circuits specially adapted for controlling the RF discharge · CPC title

• H01J37/32146

  Amplitude modulation, includes pulsing · CPC title

• H01J37/32128 Primary

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

• H10P50/20

  Dry etching; Plasma etching; Reactive-ion etching · CPC title