Dynamic Arc Management in Plasma Processing Chambers
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Solution Overview
Problem
Existing arc mitigation techniques in plasma processing chambers reduce processing efficiency and throughput by shunting power for a fixed period, which can be longer than necessary for arcs that decay quickly, leading to inefficient recovery of power delivery.
Innovation Solution
A power supply system with an arc management module that detects individual arc decay rates and dynamically adjusts the power delivery by reducing voltage when an arc is detected, monitoring current levels to determine when it falls to a safe threshold, and then resuming power delivery when the current reaches this threshold, thereby tailoring the quench period to each arc's decay rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed shunt period is used to ensure all arcs are extinguished, then arc safety is improved, but processing efficiency and throughput deteriorate due to unnecessarily long power diversion
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed shunt period to a dynamic shunt period that adapts to individual arc characteristics. The system monitors arc current in real-time and determines the shunt period based on the actual decay rate of each arc, allowing the power diversion duration to be optimized for each specific arc event rather than using a conservative fixed time that applies to all arcs.
Solution Approach 2:
The patent implements feedback by continuously monitoring the arc current during the shunt period and using this information to determine when to terminate the power diversion. The system measures the decay of arc current and compares it against threshold criteria, automatically ending the shunt period when the arc has decayed sufficiently, thereby preventing unnecessarily long power diversions while ensuring safe arc extinction.
2Productivity
If power is quickly returned to steady state after arc detection, then processing efficiency is improved, but the risk of arc flare-up or new arc formation increases
Solution Approach 1:
The patent uses feedback by continuously monitoring arc current during the shunt period and using this real-time information to determine the optimal moment to restore power. The system waits until the arc current decays to a predetermined threshold level before terminating the shunt period and restoring power, ensuring that power is returned only when it is safe to do so, thus preventing arc flare-up while minimizing processing time loss.
Solution Approach 2:
The patent applies preliminary action by proactively monitoring arc current decay during the shunt period and preparing to restore power as soon as safety criteria are met. The system has predetermined threshold levels and restoration criteria established in advance, allowing it to quickly and safely restore power once the arc has decayed sufficiently, thereby minimizing the time power is diverted while ensuring arc stability.
3Reliability
If a long shunt period is used to accommodate slow-decaying arcs, then arc extinction reliability is improved, but time loss increases for quickly decaying arcs
Solution Approach 1:
The patent applies dynamics by making the shunt period adaptive rather than fixed. The system determines the shunt period duration based on the actual decay characteristics of each individual arc by monitoring current decay in real-time. This allows quickly decaying arcs to have short shunt periods while slow-decaying arcs receive the extended protection they need, optimizing both reliability and time efficiency for different arc scenarios.
Solution Approach 2:
The patent implements parameter changes by using predetermined threshold levels for arc current decay that trigger shunt period termination. The system monitors the arc current parameter and compares it against threshold values, automatically adjusting the shunt period duration based on how quickly the arc current decays. This parameter-based control allows the system to adapt the shunt period length to match the actual arc decay rate, reducing time loss for fast-decaying arcs while maintaining reliability for slow-decaying arcs.
Data Source
AI summary
This disclosure describes systems, methods, and apparatuses for extinguishing electrical arcs in a plasma processing chamber. Once an arc is detected, the steady state voltage provided to the plasma processing chamber can be reduced, and the current being provided to the chamber decays below a steady state value as the arc is extinguished. When the current falls to or below a current threshold, the voltage can be ramped back up bringing the voltage and current back to steady state values. This technique enables power to return to a steady state level faster than traditional arc mitigation techniques.