Frequency and match tuning in one state and frequency tuning in the other state

Patent metadata

Field	Value
Publication number	US-10009028-B2
Application number	US-201715683568-A
Country	US
Kind code	B2
Filing date	Aug 22, 2017
Priority date	Sep 30, 2016
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

Systems and methods for frequency and match tuning in one state S 1 and frequency tuning in another state S 2 are described. The systems and methods include determining one or more variables for the states S 1 and S 2 , and tuning a frequency for the state S 1 of a radio frequency (RF) generator based on the one or more variables.

First claim

The invention claimed is:

1. A method for achieving reduction in power reflected towards a radio frequency (RF) generator, comprising:
providing a plurality of set points to the RF generator, wherein the set points include a frequency set point for a first state of a digital pulsed signal, a frequency set point for a second state of the digital pulsed signal, a power set point for the first state of the digital pulsed signal, and a power set point for the second state of the digital pulsed signal;
adjusting an impedance matching circuit to reduce a variable for the first state to be below a pre-determined variable threshold, wherein the variable is associated with the RF generator;
determining whether the variable for the first state is stable;
adjusting the frequency set point for the second state upon determining that the variable for the first state is stable, wherein said adjusting the frequency set point for the second state is performed to reduce a variable for the second state to be lower than a pre-set variable threshold;
determining whether the variable for the second state is stable; and
changing the frequency set point for the first state in response to determining that the variable for the second state is not stable to achieve the reduction in power reflected towards the RF generator.

2. The method of claim 1 , further comprising changing the frequency set point for the first state in response to determining that the variable for the first state is not stable.

3. The method of claim 1 , further comprising:
determining whether the power set point for the first state is achieved; and
changing the frequency set point for the first state upon determining that the power set point for the first state is not achieved.

4. The method of claim 1 , further comprising:
determining whether the power set point for the second state is achieved; and
changing the frequency set point for the first state upon determining that the power set point for the second state is not achieved.

5. The method of claim 1 , wherein the variable associated with the RF generator is measured at an output of the RF generator.

6. The method of claim 1 , wherein the variable for the first state includes a magnitude of a voltage reflection coefficient, wherein said determining whether the variable for the first state is stable includes determining whether the magnitude of the voltage reflection coefficient measured during the first state is stable.

7. The method of claim 1 , wherein the variable for the second state includes a magnitude of a voltage reflection coefficient, wherein said determining whether the variable for the second state is stable includes determining whether the magnitude of the voltage reflection coefficient measured during the second state is stable.

8. The method of claim 1 , wherein the frequency set point for the first state is a value of frequency of an RF signal to be supplied by the RF generator during the first state, wherein the frequency set point for the second state is a value of frequency of the RF signal to be supplied by the RF generator during the second state, wherein the power set point for the first state is a value of power of the RF signal to be supplied by the RF generator during the first state, wherein the power set point for the second state is a value of power of the RF signal to be supplied by the RF generator during the second state.

9. A system for achieving reduction in power reflected towards a radio frequency (RF) generator, comprising:
an RF generator configured to generate an RF signal;
an impedance matching network coupled to the RF generator for receiving the RF signal to generate a modified RF signal;
a plasma chamber coupled to the impedance matching network for receiving the modified RF signal;
a host computer system coupled to the RF generator, wherein the host computer system includes a processor configured to:
provide a plurality of set points to the RF generator, wherein the set points include a frequency set point for a first state of a digital pulsed signal, a frequency set point for a second state of the digital pulsed signal, a power set point for the first state of the digital pulsed signal, and a power set point for the second state of the digital pulsed signal;
adjust the impedance matching network to reduce a variable for the first state to be below a pre-determined variable threshold, wherein the variable for the first state is associated with the RF generator;
determine whether the variable for the first state is stable;
adjust the frequency set point for the second state upon determining that the variable for the first state is stable, wherein the frequency set point for the second state is adjusted to reduce a variable for the second state to be lower than a pre-set variable threshold;
determine whether the variable for the second state is stable; and
change the frequency set point for the first state in response to determining that the variable for the second state is not stable to achieve the reduction in power reflected towards the RF generator.

10. The system of claim 9 , wherein the processor is further configured to change the frequency set point for the first state in response to determining that the variable for the first state is not stable.

11. The system of claim 9 , wherein the processor is further configured to:
determine whether the power set point for the first state is achieved; and
change the frequency set point for the first state upon determining that the power set point for the first state is not achieved.

12. The system of claim 9 , wherein the processor is further configured to:
determine whether the power set point for the second state is achieved; and
change the frequency set point for the first state upon determining that the power set point for the second state is not achieved.

13. The system of claim 9 , wherein the variable associated with the RF generator is measured at an output of the RF generator.

14. The system of claim 9 , wherein the variable for the first state includes a magnitude of a voltage reflection coefficient, wherein to determine whether the variable for the first state is stable, the processor is configured to determine whether the magnitude of the voltage reflection coefficient measured during the first state is stable.

15. The system of claim 9 , wherein the variable for the second state includes a magnitude of a voltage reflection coefficient, wherein to determine whether the variable for the second state is stable, the processor is configured to determine whether the magnitude of the voltage reflection coefficient measured during the second state is stable.

16. The system of claim 9 , wherein the frequency set point for the first state is a value of frequency of the RF signal to be supplied by the RF generator during the first state, wherein the frequency set point for the second state is a value of frequency of the RF signal to be supplied by the RF generator during the second state, wherein the power set point for the first state is a value of power of the RF signal to be supplied by the RF generator during the first state, wherein the power set point for the second state is a value of power of the RF signal to be supplied by the RF generator during the second state.

17. A non-transitory computer readable medium storing a program causing a computer to execute a plurality of operations for achieving a reduction in power reflected towards a radio frequency (RF) generator, the operations comprising:
providing a plurality of set points to the RF generator, whe

Assignees

• Lam Res Corp

Inventors

• Wu Ying

Classifications

• H10P14/6336

  in the presence of a plasma [PECVD] · CPC title

• H10P14/6319

  Formation by plasma treatments, e.g. plasma oxidation of the substrate · CPC title

• H03K19/00361

  in field effect transistor circuits · CPC title

• H04B2001/1072

  by tuning the receiver frequency · CPC title

• H01J37/32183 Primary

  Matching circuits · CPC title