Plasma Arc Suppression Circuit for Fast RF Power Dissipation
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Solution Overview
Problem
Plasma arc events during plasma vapor deposition processes cause yield-reducing defects in semiconductor wafer fabrication due to flashes of light and heat, leading to electrical discharges and rapid energy releases, which existing technologies struggle to effectively suppress.
Innovation Solution
A system and method involving an arc suppression device that quickly detects plasma arcing by monitoring impedance changes and rapidly switches a power dissipator to reduce power delivery to the plasma chamber, mitigating or extinguishing the arc event, with the switching occurring at least an order of magnitude faster than traditional impedance matching networks can react.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional impedance matching networks are used to suppress plasma arcing, then the system can respond to impedance changes, but the response time is too slow (order of hundredths of milliseconds or more), allowing arc events to cause defects
Solution Approach 1:
The system segments the arc suppression function into two distinct components: (1) a fast-acting arc detection and suppression circuit that operates independently at microsecond timescales, and (2) a traditional impedance matching network that handles slower impedance variations. This segmentation allows the critical fast response function to be isolated from the slower matching network, resolving the contradiction between response speed and suppression effectiveness.
Solution Approach 2:
The patent introduces an intermediary arc detection circuit that monitors plasma impedance and triggers the suppression mechanism. This intermediary component acts as a mediator between the plasma chamber and the suppression system, enabling rapid detection and response to arc events before they can cause wafer defects, thus improving both response speed and suppression effectiveness.
2Object-affected harmful factors
If power is rapidly reduced to suppress plasma arcing, then arc events are extinguished, but this causes sudden impedance changes that reflect power back to the RF generator
Solution Approach 1:
The system implements beforehand cushioning by providing a controlled impedance path for reflected power. When the arc suppression mechanism rapidly reduces power to extinguish an arc, the impedance matching network is pre-configured to absorb and dissipate the reflected power safely, preventing damage to the RF generator while still achieving effective arc suppression.
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
Effectively suppresses plasma arcing, reducing energy delivery to the plasma chamber and minimizing defects in semiconductor wafers by maintaining a stable load impedance and reducing reflection coefficients, thereby enhancing the stability and efficiency of the RF generator.
Implementation Method 1
An arc suppression device coupled to the RF generator and the plasma chamber detects plasma arcing causing a sharp impedance change
Implementation Method 2
switches a power dissipator reducing the power delivered to the plasma chamber
Data Source
AI summary
A method and system for plasma arc suppression includes a RF generator supplying power to a plasma chamber coupled to an impedance matching network reacting to impedance changes to match an impedance of the plasma chamber with an impedance of the radio frequency generator. An arc suppression device coupled to the RF generator and the plasma chamber detects plasma arcing causing a sharp impedance change increasing reflection of the power by the plasma chamber and switches a power dissipator reducing the power delivered to the plasma chamber extinguishing or mitigating the plasma arcing. The power dissipator is switched more quickly than the impedance matching network reacts to the sharp impedance change. For example, the impedance matching network may react to the impedance change on an order of hundredths of milliseconds or more, while the arc suppression device switches the power dissipator on an order of microseconds or less.