Systems and methods for reducing reflected power during state transitions by using radio frequency values

Patent metadata

Field	Value
Publication number	US-2016307736-A1
Application number	US-201615098566-A
Country	US
Kind code	A1
Filing date	Apr 14, 2016
Priority date	May 9, 2013
Publication date	Oct 20, 2016
Grant date	—

Abstract

Systems and methods for tuning an impedance matching network in a step-wise fashion for each state transition are described. By tuning the impedance matching network in a step-wise fashion for each state transition instead of directly achieving an optimal value of a combined variable capacitance for each state, processing of a wafer using the tuned optimal values becomes feasible.

First claim

1 . A method for reducing reflected power during state transitions by using radio frequency values, comprising:
receiving during a first type of state transition of a radio frequency (RF) generator a first plurality of measured input parameter values sensed between an output of the RF generator and an input of an impedance matching network when the RF generator operates at a first plurality of parametric values and the impedance matching network has a first variable measurable factor; initializing for the first type of state transition one or more models to have the first variable measurable factor and the first plurality of parametric values, wherein the one or more models include a model of the impedance matching network; calculating for the first type of state transition a first plurality of output parameter values using the one or more models from the first plurality of measured input parameter values when the one or more models have the first variable measurable factor and the first plurality of parametric values; calculating, using the first plurality of output parameter values and the one or more models, a first plurality of favorable parametric values, wherein for each of the favorable parametric values of the first plurality, a reflection coefficient for the first type of state transition at an input of the one or more models is minimum; controlling during the first type of state transition the RF generator to operate at the first plurality of favorable parametric values.

2 . The method of claim 1 , wherein said receiving, initializing, calculating the first plurality of output parameter values, and calculating the first plurality of favorable parametric values are performed during a first occurrence of the first type of state transition, wherein said controlling is performing is performed during a second occurrence of the first type of state transition.

3 . The method of claim 2 , wherein the second occurrence follows the first occurrence after one or more intermediate occurrences of the first type of state transition.

4 . The method of claim 2 , wherein the second occurrence immediately follows the first occurrence without any occurrences of the first type of state transition occurring between the first occurrence and the second occurrence.

5 . The method of claim 1 , further comprising:
receiving during a second type of state transition of the RF generator a second plurality of measured input parameter values sensed between the output of the RF generator and the input of the impedance matching network when the RF generator operates at a second plurality of parametric values and the impedance matching network has the first variable measurable factor; initializing for the second type of state transition the one or more models of the impedance matching network to have the first variable measurable factor and the second plurality of parametric values; calculating for the second type of state transition a second plurality of output parameter values using the one or more models from the second plurality of measured input parameter values when the one or more models has the first variable measurable factor and the second plurality of parametric values; calculating, using the second plurality of output parameter values and the one or more models, a second plurality of favorable parametric values, wherein for each of the favorable parametric values of the second plurality, the reflection coefficient for the second type of state transition at the input of the one or more models is minimum; controlling during the second type of state transition the RF generator to operate at the second plurality of favorable parametric values.

6 . The method of claim 5 , wherein said receiving the second plurality of measured input parameter values, initializing for the second type of state transition, calculating the second plurality of output parameter values, and calculating the second plurality of favorable parametric values are performed during a first occurrence of the second type of state transition, wherein said controlling is performing is performed during a second occurrence of the second type of state transition.

7 . The method of claim 6 , wherein the second occurrence of the second type of state transition follows the first occurrence of the second type of state transition after one or more intermediate occurrences of the second type of state transition.

8 . The method of claim 6 , wherein the second occurrence of the second type of state transition immediately follows the first occurrence of the second type of state transition without any occurrences of the second type of state transition occurring between the first occurrence of the second type of state transition and the second occurrence of the second type of state transition.

9 . The method of claim 5 , further comprising:
receiving during the first type of state transition of the RF generator a third plurality of measured input parameter values sensed between the output of the RF generator and the input of the impedance matching network when the RF generator operates at the first plurality of favorable parametric values and the impedance matching network has a first step variable measurable factor; initializing for the first type of state transition the one or more models of the impedance matching network to have the first step variable measurable factor and the first plurality of favorable parametric values; calculating for the first type of state transition a third plurality of output parameter values using the one or more models from the third plurality of measured input parameter values when the one or more models has the first step variable measurable factor and the first plurality of favorable parametric values; calculating, using the third plurality of output parameter values and the one or more models, a third plurality of favorable parametric values, wherein for each of the favorable parametric values of the third plurality, the reflection coefficient for the first type of state transition at the input of the one or more models is minimum; controlling during the first type of state transition the RF generator to operate at the third plurality of favorable parametric values.

10 . The method of claim 9 , further comprising:
receiving during the second type of state transition of the RF generator a fourth plurality of measured input parameter values sensed between the output of the RF generator and the input of the impedance matching network when the RF generator operates at the second plurality of favorable parametric values and the impedance matching network has the first step variable measurable factor; initializing for the second type of state transition the one or more models of the impedance matching network to have the first step variable measurable factor and the second plurality of favorable parametric values; calculating for the second type of state transition a fourth plurality of output parameter values using the one or more models from the fourth plurality of measured input parameter values when the one or more models has the first step variable measurable factor and the second plurality of favorable parametric values; calculating, using the fourth plurality of output parameter values and the one or more models, a fourth plurality of favorable parametric values, wherein for each of the favorable parametric values of the fourth plurality, the reflection coefficient for the second type of state transition at the input of the one or more models is minimum; controlling during the second type of state transition the RF generator to operate at the fourth plurality of favorable parametric values.

11 . The method of

Assignees

• Lam Res Corp

Inventors

• Howald Arthur M
• Valcore Jr John C
• Fong Andrew
• Hopkins David

Classifications

• H01J37/32926

  Software, data control or modelling · CPC title

• G06F30/36

  Circuit design at the analogue level · CPC title

• H01J37/32183 Primary

  Matching circuits · CPC title