Plasma Processing Chamber Warm-Up Control for Etching Rate Consistency
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Solution Overview
Problem
In plasma processing devices, the etching rate of the first target substrate in a lot can be lower due to the decreased inner surface temperature of the processing chamber, leading to reduced throughput and processing accuracy, as existing methods like seasoning with a dummy wafer reduce the number of substrates processed per unit time.
Innovation Solution
A plasma processing device with a control unit that performs a warm-up process by supplying processing gas and electromagnetic energy into the chamber before transferring the target substrate, maintaining the chamber temperature without reducing throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If seasoning is performed by loading a dummy wafer and performing a plasma generating process before processing target substrates, then the temperature of the inner surface of the processing chamber is increased and etching rate reduction is prevented, but the number of target substrates processed per unit time is reduced
Solution Approach 1:
The patent performs a warm-up process by supplying electromagnetic energy and processing gas into the processing chamber before the target substrate is transferred in. This preliminary action increases the inner surface temperature of the processing chamber in advance, ensuring that when the first target substrate is processed, the temperature is already sufficient to maintain consistent etching rate, thereby eliminating the need for dummy wafer seasoning while preserving throughput
Solution Approach 2:
The patent extracts the dummy wafer from the seasoning process and replaces it with a substrate-less warm-up process. By separating the temperature preparation function from the substrate processing function, the system can maintain chamber temperature without sacrificing productive time to dummy wafer handling and processing
2Productivity
If the plasma process is performed after a lapse of a period of time from when a previous plasma process is performed, then the processing chamber is available for next use, but the temperature of the inner surface of the processing chamber is decreased leading to lower etching rate
Solution Approach 1:
The system performs a warm-up process immediately before substrate transfer that supplies electromagnetic energy and processing gas to increase the inner surface temperature of the processing chamber. This preliminary temperature preparation ensures that even after time lapses between processing batches, the chamber temperature is restored to the required level before the first substrate of the new lot is processed, maintaining etching rate consistency
Solution Approach 2:
The control unit monitors the state of the processing chamber and determines when to perform the warm-up process based on timing information from substrate processing cycles. This feedback mechanism ensures the warm-up is triggered at appropriate intervals to maintain temperature without unnecessarily reducing device availability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method maintains the etching rate of the first lot substrates equal to subsequent substrates while preventing a reduction in plasma process throughput by ensuring consistent chamber temperature during processing.
Implementation Method 1
a plasma generation mechanism configured to supply electromagnetic energy for converting the processing gas introduced into the plasma processing space to plasma
Implementation Method 2
supply electromagnetic energy by the plasma generation mechanism in a state where no target substrate is mounted on the substrate mounting stage
Data Source
AI summary
A plasma processing device includes a processing chamber defining a plasma processing space and a stage for mounting thereon a target substrate in the processing chamber. The plasma processing device further includes a gas supply mechanism for introducing a processing gas into the plasma processing space, a plasma generation mechanism for supplying electromagnetic energy into the plasma processing space, and a control unit configured to, if a command to start a plasma process for the target substrate mounted on a substrate carry-in stage is issued, perform a warm-up process for supplying the processing gas into the plasma processing space by the gas supply mechanism and supplying the electromagnetic energy by the plasma generation mechanism in a state where no target substrate is mounted on the stage.