Component temperature control by coolant flow control and heater duty cycle control

Patent metadata

Field	Value
Publication number	US-9639097-B2
Application number	US-201414497253-A
Country	US
Kind code	B2
Filing date	Sep 25, 2014
Priority date	May 27, 2010
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

Methods and systems for controlling temperatures in plasma processing chamber for a wide range of setpoint temperatures and reduced energy consumption. Temperature control is coordinated between a coolant liquid loop and a heat source by a control algorithm implemented by the plasma processing module controller. The control algorithm may completely stop the flow of coolant liquid to a temperature-controlled component in response to a feedback signal indicating an actual temperature is below the setpoint temperature. The control algorithm may further be based at least in part on a feedforward control signal derived from a plasma power or change in plasma power input into the processing chamber during process recipe execution.

First claim

What is claimed is:

1. A temperature controller, comprising:
a feedforward input to receive an indication of a plasma power to be input to a plasma processing chamber during execution of a process recipe;
a feedback input to receive an indication of an actual temperature of a component to be controlled to a setpoint temperature by the temperature controller;
a processor to execute a temperature control algorithm having a feedback portion that generates a control effort based on a difference between the actual temperature feedback input and the setpoint temperature; and
an actuator output to provide an actuator signal generated by the processor from the temperature control algorithm, the actuator signal to completely stop a coolant liquid flow to the temperature-controlled component when the temperature falls below the setpoint temperature.

2. The temperature controller as in claim 1 , wherein the control algorithm further includes a feedforward portion that generates a control effort based on the plasma power feedforward input to reduce an effect of the plasma power on a temperature of the component.

3. The temperature controller as in claim 2 , wherein the processor is to further generate the feedforward control effort based on a first group of gain values associated with a key value pairing of a change in the plasma input power and a change in the setpoint temperature between the executing step and a preceding or subsequent plasma process recipe step.

4. The temperature controller as in claim 3 , wherein the processor is to further generate the feedforward control effort based on a group of transient gain values associated with a key value pairing of a change in the plasma input power and a change in the setpoint temperature between the executing step and a preceding or subsequent plasma process recipe step.

5. The temperature controller as in claim 4 , wherein the group of transient gain values are applied for a duration dependent on the temperature of the component to be controlled and the change in the setpoint temperature.

6. The temperature controller as in claim 3 , wherein the actuator signal is to modulate a pulse width modulation duty cycle to fully open and fully close a valve through which the coolant liquid flows, the pulse width modulation based at least in part on the first group of gain values.

7. The temperature controller as in claim 2 , wherein the processor is to further modify the liquid coolant flow rate based on a lookup table value in response to the component temperature crossing a threshold level when the chamber is in an idle state.

8. The temperature controller as in claim 2 , wherein the plasma power comprises a first bias power input to a chuck configured to support a workpiece and wherein the plasma power feedforward input comprises a transfer function between the first bias power input and the temperature of the temperature-controlled component.

9. The temperature controller as in claim 8 , wherein the temperature-controlled component is a process gas showerhead and wherein the coolant liquid flow to the temperature-controlled component passes through a coolant channel embedded in the showerhead.

10. The temperature controller as in claim 9 , wherein m independently controlled heating elements are embedded within the showerhead, wherein the coolant loop is one of n coolant loops embedded in the showerhead, and m is not equal to n.

11. A temperature controller, comprising:
a feedforward input to receive an indication of a plasma power to be input to a plasma processing chamber during execution of a process recipe;
a feedback input to receive an indication of an actual temperature of a component to be controlled to a setpoint temperature by the temperature controller, wherein the temperature-controlled component is a process gas showerhead;
a processor to execute a temperature control algorithm having a feedback portion that generates a control effort based on a difference between the actual temperature feedback input and the setpoint temperature, wherein the control algorithm further includes a feedforward portion that generates a control effort based on the plasma power feedforward input to reduce an effect of the plasma power on a temperature of the component, and wherein the processor is to further generate the feedforward control effort based on a first group of gain values associated with a key value pairing of a change in the plasma input power and a change in the setpoint temperature between the executing step and a preceding or subsequent plasma process recipe step; and
an actuator output to provide an actuator signal generated by the processor from the temperature control algorithm, the actuator signal to completely stop a coolant liquid flow to the temperature-controlled component when the temperature falls below the setpoint temperature.

12. The temperature controller as in claim 11 , wherein the processor is to further generate the feedforward control effort based on a first group of gain values associated with a key value pairing of a change in the plasma input power and a change in the setpoint temperature between the executing step and a preceding or subsequent plasma process recipe step.

13. The temperature controller as in claim 12 , wherein the processor is to further generate the feedforward control effort based on a group of transient gain values associated with a key value pairing of a change in the plasma input power and a change in the setpoint temperature between the executing step and a preceding or subsequent plasma process recipe step.

14. The temperature controller as in claim 11 , wherein the processor is to further modify the liquid coolant flow rate based on a lookup table value in response to the component temperature crossing a threshold level when the chamber is in an idle state.

15. The temperature controller as in claim 11 , wherein the coolant liquid flow to the temperature-controlled component passes through a coolant channel embedded in the showerhead.

Assignees

• Applied Materials Inc

Inventors

• Mahadeswaraswamy Chetan
• Ramaswamy Kartik
• Liao Bryan
• Shoji Sergio
• Nguyen Duy D
• Noorbakhsh Hamid
• Palagashvili David

Classifications

• H10P72/0602

  Temperature monitoring · CPC title

• H01J37/3299

  Feedback systems · CPC title

• H01J37/32908

  Utilities · CPC title

• G05B15/02

  electric · CPC title

• G05D23/19 Primary

  characterised by the use of electric means {(G05D23/1393 takes precedence)} · CPC title