Feedforward temperature control for plasma processing apparatus

摘要

Methods and systems for controlling temperatures in plasma processing chamber with reduced controller response times and increased stability. Temperature control is based at least in part on a feedforward control signal derived from a plasma power input into the processing chamber. A feedforward control signal compensating disturbances in the temperature attributable to the plasma power may be combined with a feedback control signal counteracting error between a measured and desired temperature.

主权项

1. A method for controlling a process temperature during a plasma processing of a workpiece, comprising:
determining a plasma power input to a process chamber performing the plasma processing on the workpiece; determining a feedback gain value and a feedforward gain value from a lookup table, wherein the lookup table includes a plurality of feedforward gain values and feedback gain values that are each associated with at least one of the plasma power input, a setpoint process temperature, a change in the plasma power input, or a change in the setpoint process temperature; combining a feedback control signal with a feedforward control signal based on the plasma power to create a temperature control signal, wherein the feedback control signal is multiplied by the feedback gain value and the feedforward control signal is multiplied by the feedforward gain value; and controlling a temperature in the process chamber with said temperature control signal.