Predictive Plasma Power Control for Actuator Delay Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Plasma processing systems face challenges in controlling actuators due to differential response times and asynchronous operations, leading to inefficiencies and premature system failure, particularly in achieving precise and consistent power delivery in plasma etch and deposition processes.
Innovation Solution
A plasma processing control system that includes a user interface for receiving target values, sensors for measuring actual values, a delay/amplitude estimator to calculate time-shifted amplitude errors, and a predictive control section to adjust actuators in advance, ensuring the controlled parameter remains within a threshold range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the rail voltage is held at a high level for much of a pulse cycle to ensure sufficient power for fast actuators, then the power delivery reliability is improved, but the energy dissipation increases and components overheat leading to premature system failure
Solution Approach 1:
The control system performs preliminary action by adjusting the rail voltage in advance of when it is actually needed by the fast actuators. The predictive control section calculates the required rail voltage based on the reference signal and actuator response characteristics, then adjusts the DC section output beforehand. This allows the rail to be at the correct voltage level when needed without being held at high levels continuously, reducing energy dissipation while maintaining power delivery reliability.
Solution Approach 2:
The system implements dynamics by making the rail voltage adjustable and time-varying rather than static. The predictive control section dynamically adjusts the DC section output based on real-time requirements, matching the rail voltage to the actual needs of the fast actuators at different moments in the pulse cycle. This dynamic adjustment prevents both over-voltage (reducing energy waste) and under-voltage (maintaining reliability).
2Measurement precision
If the DC section response time is increased to match the slower rail voltage changes, then the control precision is improved, but the productivity decreases due to slower overall system response
Solution Approach 1:
The control system performs preliminary action by adjusting the rail voltage in advance of when it is actually needed by the fast actuators. The predictive control section calculates the required rail voltage based on the reference signal and actuator response characteristics, then adjusts the DC section output beforehand. This allows the rail to be at the correct voltage level when needed without being held at high levels continuously, reducing energy dissipation while maintaining power delivery reliability.
Solution Approach 2:
The system implements dynamics by making the rail voltage adjustable and time-varying rather than static. The predictive control section dynamically adjusts the DC section output based on real-time requirements, matching the rail voltage to the actual needs of the fast actuators at different moments in the pulse cycle. This dynamic adjustment prevents both over-voltage (reducing energy waste) and under-voltage (maintaining reliability).
3Ease of operation
If multiple actuators with different response times are operated asynchronously to maintain flexibility, then the ease of operation is improved, but the manufacturing precision deteriorates due to difficulty in coordinating actuator responses
Solution Approach 1:
The control system implements feedback by using sensors to obtain actual values of the controlled parameter and comparing them with target values from the reference signal. The delay/amplitude estimator calculates the delay between target and actual values, and this feedback information is used by the predictive control section to adjust actuator commands. This closed-loop feedback ensures precise coordination of multiple actuators with different response times, maintaining both operational flexibility and manufacturing precision.
Solution Approach 2:
The control system performs preliminary action by adjusting the rail voltage in advance of when it is actually needed by the fast actuators. The predictive control section calculates the required rail voltage based on the reference signal and actuator response characteristics, then adjusts the DC section output beforehand. This allows the rail to be at the correct voltage level when needed without being held at high levels continuously, reducing energy dissipation while maintaining power delivery reliability.
Data Source
AI summary
This disclosure describes systems, methods, and apparatus for a plasma processing system. A method comprises receiving a reference signal defining target values for a parameter that is controlled at an output within the plasma processing system, obtaining a measure of the parameter that is controlled at the output, and calculating a delay between the target values of the setpoint signal and corresponding actual parameter values achieved at the output. The method also comprises providing, based upon the delay, a time-shifted amplitude error indicative of an error between the target values and the actual parameter values and adjusting at least one actuator, based upon the delay and the time-shifted amplitude error, in advance of when an actual parameter value is desired at an actuator output of the at least one actuator while maintaining the output within a threshold range.