Switchable Edge Ring Coupling for Reduced Plasma Processing Wear
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Solution Overview
Problem
The existing plasma processing apparatuses face challenges in reducing the wear of the edge ring, which is subjected to the harsh environment of plasma processing.
Innovation Solution
The proposed plasma processing apparatus includes a lifter mechanism that raises and lowers the edge ring, allowing it to be electrically coupled or disconnected from the base, thereby reducing wear by controlling the exposure to plasma.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the edge ring is continuously electrically coupled to the base during plasma processing, then the substrate processing function is maintained, but the edge ring wear increases
Solution Approach 1:
The patent applies the dynamics principle by making the electrical coupling state of the edge ring changeable rather than fixed. The system dynamically switches between connected and disconnected states based on processing requirements. The lifter mechanism raises or lowers the edge ring to control electrical coupling with the base, allowing the system to adapt the coupling state during different processing phases, thereby reducing wear during non-critical periods while maintaining functionality when needed.
Solution Approach 2:
The patent implements periodic action by alternating between connected and disconnected states of the edge ring. Rather than maintaining continuous electrical coupling, the system periodically connects the edge ring to the base only when substrate processing requires it, and disconnects during other phases. This periodic engagement reduces cumulative wear on the edge ring while ensuring proper electrical coupling is available when needed for plasma processing.
2Duration of action of stationary object
If the edge ring is raised and lowered frequently to control plasma exposure, then wear is reduced, but the device complexity increases
Solution Approach 1:
The patent applies universality by designing the lifter mechanism to perform multiple functions simultaneously. The same lifter structure that raises and lowers the edge ring also serves as the electrical connection path and provides mechanical support. This multi-functionality reduces the need for separate components for each function, thereby limiting the increase in overall device complexity despite adding the height adjustment capability.
Solution Approach 2:
The lifter mechanism acts as an intermediary between the edge ring and the base, providing a controlled interface that manages both mechanical support and electrical coupling. Rather than requiring complex separate systems for positioning and electrical connection, the lifter serves as a mediating component that handles both functions through its structural design, thus managing complexity by consolidating functions through a single intermediary mechanism.
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
The technique effectively reduces the wear of the edge ring by controlling its electrical coupling with the base, thereby minimizing exposure to plasma and extending the lifespan of the edge ring.
Implementation Method 1
The substrate support includes a base and an electrostatic chuck on the base
Implementation Method 2
The plasma generator includes a radio-frequency power supply to generate plasma in the chamber
Implementation Method 3
The bias power supply generates an electrical bias to draw ions from the plasma into a substrate on the substrate support
Data Source
AI summary
A plasma processing apparatus includes a chamber, a substrate support in the chamber, a plasma generator, a bias power supply, an edge ring, a lifter, a switch, and a controller. At least one of the bias power supply or a radio-frequency power supply in the plasma generator is electrically coupled to a base in the substrate support. The lifter includes a conductive ring, a rod, an actuator, and a connector. The lifter raises and lowers the edge ring supported on the conductive ring. The connector electrically couples the conductive ring and the base. The switch changes between a first state in which the edge ring and the base are electrically coupled to each other and a second state in which the edge ring and the base are electrically disconnected from each other. The controller controls the switch.