IP Library › Granted Patent US 12706278
Granted Patent B2
US 12706278 · App. 18/685,884 · Granted Aug 11, 2026

Hybrid frequency plasma source

Inventors: Yuhou Wang (Fremont, CA); Alexander Miller Paterson (San Jose, CA); John Stephen Drewery (San Jose, CA); Ying Wu (Livermore, CA)
Assignee: Lam Research Corporation
H01J37/32183H01J37/32165
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Quick Facts
Patent No.
US 12706278
App. No.
18/685,884
Filed
Feb 22, 2024
Granted
Aug 11, 2026
Kind
B2
Examiner
LUQUE, RENAN
Art Unit
2845
USPC
315/111.21
Abstract

A plasma system includes a first matchless plasma source (MPS) that generates a first sinusoidal waveform having a first frequency. The plasma system includes a first filter coupled to the first MPS to filter a second frequency. The plasma system further includes a first capacitive circuit coupled to the first filter to balance reactances of the first filter and a radio frequency (RF) coil to further provide a first RF signal to a point. The plasma system includes a second MPS that generates a second sinusoidal waveform having the second frequency. The plasma system includes a second filter coupled to the second MPS to filter the first frequency. The plasma system includes a second capacitive circuit that is coupled to the second filter to balance a reactance of the second filter with the reactance of the RF coil to further provide a second RF signal to the point.

Claims (50)

1 . A system comprising:

a first matchless plasma source configured to generate a first sinusoidal waveform, wherein the first sinusoidal waveform is generated based on a first square waveform, wherein the first sinusoidal waveform has a first frequency;

a first filter coupled to the first matchless plasma source, wherein the first filter is configured to filter a second frequency from interfering with the first sinusoidal waveform;

a first capacitive circuit coupled to the first filter, wherein the first capacitive circuit is configured to balance a reactance of the first filter with a reactance of an RF coil of a plasma chamber to output a first radio frequency (RF) signal, wherein the first capacitive circuit is configured to provide the first RF signal to a point that is coupled to the RF coil;

a second matchless plasma source configured to generate a second sinusoidal waveform, wherein the second sinusoidal waveform is generated based on a second square waveform, wherein the second sinusoidal waveform has the second frequency;

a second filter coupled to the second matchless plasma source, wherein the second filter is configured to filter the first frequency from interfering with the second sinusoidal waveform; and

a second capacitive circuit coupled to the second filter, wherein the second capacitive circuit is configured to balance a reactance of the second filter with the reactance of the RF coil to output a second RF signal, wherein the second capacitive circuit is configured to provide the second RF signal to the point.

2 . The system of claim 1 , wherein the first RF signal is combined with the second RF signal at the point to provide a combined RF signal to the RF coil.

3 . The system of claim 1 , wherein the second frequency is greater than the first frequency.

4 . The system of claim 1 , further comprising the plasma chamber including the RF coil and a substrate support.

5 . The system of claim 4 , further comprising:

a first bias RF generator configured to generate a third RF signal;

a match coupled to the first bias RF generator;

a second bias RF generator coupled to the match, wherein the second bias RF generator is configured to generate a fourth RF signal, wherein the match is configured to receive the third and fourth RF signals and modify impedances of the third and fourth RF signals to output a combined RF signal, wherein the match is configured to provide the combined RF signal to the substrate support.

6 . The system of claim 4 , wherein the substrate support is coupled to a ground potential.

7 . The system of claim 1 , wherein the first capacitive circuit is configured to receive a reflected RF signal having RF power reflected from the plasma chamber, wherein the reflected RF signal has the second frequency.

8 . The system of claim 1 , wherein the second capacitive circuit is configured to receive a reflected RF signal having RF power reflected from the plasma chamber, wherein the reflected RF signal has the first frequency.

9 . The system of claim 1 , wherein there is a lack of a match between the first matchless plasma source and the RF coil and there is a lack of a match between the second matchless plasma source and the RF coil.

10 . A system comprising:

a matchless plasma source configured to generate a sinusoidal waveform, wherein the sinusoidal waveform is generated based on a square waveform, wherein the sinusoidal waveform has a first frequency;

a first filter coupled to the matchless plasma source, wherein the first filter is configured to filter a second frequency from interfering within the sinusoidal waveform;

a capacitive circuit coupled to the first filter, wherein the capacitive circuit is configured to balance a reactance of the first filter with a reactance of an RF coil of a plasma chamber to output a first radio frequency (RF) signal, wherein the capacitive circuit is configured to provide the first RF signal to a point that is coupled to the RF coil;

a source RF generator configured to generate a second RF signal having the second frequency; and

an impedance matching network coupled to the source RF generator, wherein the impedance matching network is configured to receive the second RF signal and modify an impedance of the second RF signal to output a modified RF signal, wherein the impedance matching network includes a second filter, wherein the second filter is configured to filter the first frequency from interfering with the second RF signal, wherein the impedance matching network is configured to provide the modified RF signal to the point.

11 . The system of claim 10 , wherein the point is configured to combine the first RF signal with the modified RF signal to provide a combined RF signal to the RF coil.

12 . The system of claim 10 , wherein the second frequency is greater than the first frequency or is equal to the first frequency or is less than the first frequency.

13 . The system of claim 10 , further comprising the plasma chamber including the RF coil and a substrate support.

14 . The system of claim 13 , further comprising:

a first bias RF generator configured to generate a third RF signal;

a match coupled to the first bias RF generator;

a second bias RF generator coupled to the match, wherein the second bias RF generator is configured to generate a fourth RF signal, wherein the match is configured to receive the third and fourth RF signals and modify impedances of the third and fourth RF signals to output a combined RF signal, wherein the match is configured to provide the combined RF signal to the substrate support.

15 . The system of claim 13 , wherein the substrate support is coupled to a ground potential.

16 . The system of claim 10 , wherein the capacitive circuit is configured to receive a reflected RF signal having RF power reflected from the plasma chamber, wherein the reflected RF signal has the second frequency.

17 . The system of claim 10 , wherein there is a lack of a match between the matchless plasma source and the RF coil, wherein the match includes a physical housing.

18 . A system comprising:

a first matchless plasma source configured to generate a first sinusoidal waveform, wherein the first sinusoidal waveform is generated based on a first square waveform, wherein the first sinusoidal waveform has a first frequency;

a first filter coupled to the first matchless plasma source, wherein the first filter is configured to filter a second frequency from interfering with the first sinusoidal waveform;

a first capacitive circuit coupled to the first filter, wherein the first capacitive circuit is configured to balance a reactance of the first filter with a reactance of a first radio frequency (RF) coil of a plasma chamber to output a first RF signal, wherein the first capacitive circuit is configured to provide the first RF signal to a point that is coupled to the first RF coil;

a second matchless plasma source configured to generate a second sinusoidal waveform, wherein the second sinusoidal waveform is generated based on a second square waveform, wherein the second sinusoidal waveform has the second frequency;

a second filter coupled to the second matchless plasma source, wherein the second filter is configured to filter the first frequency from interfering with the second sinusoidal waveform;

a second capacitive circuit coupled to the second filter, wherein the second capacitive circuit is configured to balance a reactance of the second filter with a reactance of the first RF coil and a reactance of a second RF coil of the plasma chamber to output a second RF signal; and

a signal splitter coupled to the second capacitive circuit, wherein the signal splitter is configured to split the second RF signal into a third RF signal and a fourth RF signal, wherein the signal splitter includes a third capacitive circuit and a fourth capacitive circuit, wherein the third capacitive circuit is configured to receive the third RF signal and balance the reactance of the first RF coil of the plasma chamber with the reactance of the second filter to provide a fifth RF signal to the point, wherein the fourth capacitive circuit is configured to receive the fourth RF signal and balance the reactance of the second RF coil with the reactance of the second filter to provide a sixth RF signal to the second RF coil.

19 . The system of claim 18 , wherein the point is configured to combine the first RF signal with the fifth RF signal to provide a seventh RF signal to the first RF coil.

20 . The system of claim 18 , wherein the second frequency is greater than the first frequency.

21 . The system of claim 18 , further comprising the plasma chamber including the first RF coil, the second RF coil, and a substrate support.

22 . The system of claim 21 , further comprising:

a first bias RF generator configured to generate a seventh RF signal;

a match coupled to the first bias RF generator;

a second bias RF generator coupled to the match, wherein the second bias RF generator is configured to generate an eighth RF signal, wherein the match is configured to receive the seventh and eighth RF signals and modify impedances of the seventh and eighth RF signals to output a combined RF signal, wherein the match is configured to provide the combined RF signal to the substrate support.

23 . The system of claim 21 , wherein the substrate support is coupled to a ground potential.