Plasma-Assisted Electrostatic Chuck Switching for Edge Ring Discharge
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Solution Overview
Problem
Plasma processing apparatuses face challenges in suppressing discharge between the edge ring and substrate during potential switching in electrostatic chucks, leading to potential contamination and processing inefficiencies.
Innovation Solution
The apparatus employs a controller to switch the potentials of the electrostatic chuck's electrodes between monopolar and bipolar modes during plasma processing, maintaining plasma generation to prevent large potential differences and minimize discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the potentials of the electrostatic chuck's electrodes are switched between monopolar and bipolar modes, then the edge ring can be securely held and plasma processing can be performed, but discharge may occur between the edge ring and substrate during potential switching
Solution Approach 1:
The patent applies preliminary action by maintaining plasma generation in the chamber during the potential switching process. The plasma creates a conductive medium that provides a discharge path, preventing direct discharge between the edge ring and substrate. The controller is configured to switch potentials only during periods when plasma is actively generated, ensuring protective plasma coverage exists before and during the switching event.
Solution Approach 2:
The patent uses plasma as an intermediary medium to prevent direct discharge between the edge ring and substrate. The plasma fills the chamber and provides a conductive pathway that mediates the potential differences, allowing controlled potential switching without harmful direct discharges. The plasma acts as a buffer that absorbs and redirects electrical energy away from sensitive components.
2Object-affected harmful factors
If plasma generation is maintained during potential switching, then discharge between edge ring and substrate is suppressed, but energy consumption increases
Solution Approach 1:
The patent applies periodic action by confining plasma generation to specific time periods that include the potential switching events. Rather than maintaining plasma continuously, the system generates plasma periodically during processing steps when potential switching is required, then stops plasma generation during stable processing phases. This reduces overall energy consumption while ensuring plasma is present when needed for discharge suppression during switching.
Solution Approach 2:
The system prepares plasma in advance before potential switching occurs, ensuring the protective plasma environment is already established. The controller coordinates plasma generation to start slightly before the potential switching event and continues for a brief period after switching completes, minimizing the plasma maintenance time while ensuring adequate protection during the critical switching moment.
3Object-affected harmful factors
If the switching period is extended to ensure stable plasma conditions, then discharge is better suppressed, but processing efficiency decreases
Solution Approach 1:
The patent uses periodic action to create clearly defined time segments for plasma generation and potential switching. The processing cycle is divided into discrete periods: plasma generation period, potential switching period, and plasma cessation period. This structured periodic operation ensures that potential switching always occurs within a controlled plasma environment while minimizing the total time plasma must be maintained, thereby optimizing both discharge suppression and processing efficiency.
Solution Approach 2:
The system dynamically adjusts the timing and duration of plasma generation based on the processing stage and potential switching requirements. The controller monitors processing conditions and adapts the plasma maintenance period length, extending plasma generation only as long as necessary to cover potential switching events and reducing it during stable processing phases. This dynamic timing optimization balances discharge suppression needs with processing efficiency.
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 approach effectively suppresses discharge between the edge ring and substrate, preventing contamination and ensuring efficient plasma processing by maintaining stable plasma conditions during potential switching.
Implementation Method 1
The electrostatic chuck is configured to hold the edge ring by an electrostatic force generated according to potentials respectively set on the first electrode and the second electrode
Implementation Method 2
The radio frequency power supply is configured to supply radio frequency power to generate plasma in the chamber
Data Source
AI summary
A disclose substrate support of a plasma processing apparatus has an electrostatic chuck that holds an edge ring. The electrostatic chuck includes a first electrode and a second electrode. In an execution period of a first plasma processing on a substrate, first potentials which are ones out of potentials same as each other and potentials different from each other are set to the first and second electrodes, respectively. In an execution period of a second plasma processing on the substrate, second potentials which are others out of the potentials same as each other and the potentials different from each other are set to the first and second electrodes, respectively. The respective potentials of the first electrode and the second electrode are switched from the first potentials to the second potentials.