Moveable Edge Ring Assembly for Stable Plasma Uniformity
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Solution Overview
Problem
Edge rings in plasma processing systems wear down during operation, leading to changes in capacitive coupling and plasma uniformity, requiring frequent replacement and affecting process consistency.
Innovation Solution
A moveable edge ring system comprising a cover ring, a moveable top ring, and a bottom ring, with specific geometric configurations and actuator-controlled height adjustments to maintain consistent capacitive coupling and plasma uniformity without breaking vacuum.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed edge ring is used to shape plasma, then plasma uniformity is maintained initially, but the edge ring wears down over time causing capacitive coupling variations and plasma non-uniformity
Solution Approach 1:
The edge ring is designed with a moveable top ring that can be dynamically adjusted in height relative to the substrate. An actuator mechanism enables the top ring to move vertically, allowing the system to adapt to wear by restoring the original height position, thereby maintaining consistent capacitive coupling and plasma uniformity throughout the edge ring's service life.
2Reliability
If the edge ring is replaced frequently to maintain plasma uniformity, then plasma processing consistency is improved, but system downtime increases
Solution Approach 1:
Instead of replacing the entire edge ring assembly, the system dynamically adjusts the height of the moveable top ring using an actuator. This allows restoration of the original geometric configuration and capacitive coupling without breaking vacuum or replacing components, significantly reducing downtime while maintaining plasma processing consistency.
Solution Approach 2:
The edge ring is segmented into a stationary bottom ring and a moveable top ring. The top ring can be independently adjusted or replaced, allowing maintenance operations to focus only on the worn component rather than the entire assembly, thereby reducing downtime and maintaining process consistency.
3Reliability
If the edge ring height is adjusted to compensate for wear, then capacitive coupling variations are reduced, but the system complexity increases
Solution Approach 1:
A moveable top ring with actuator mechanism is implemented to dynamically adjust height and maintain capacitive coupling stability. The actuator system includes drive mechanisms and positioning control that add complexity but enable automatic compensation for wear, ensuring consistent plasma uniformity throughout the edge ring's service life.
Data Source
AI summary
An edge ring system includes a moveable top ring and a cover ring configured to be arranged above and radially outward of the moveable top ring. The cover ring includes an annular body and a stepped portion extending radially inward from the annular body. The stepped portion is configured to extend above an outer edge of the moveable top ring. An annular recess is defined in an inner radius of the cover ring below the stepped portion. The moveable top ring includes an annular body and a curved outer radius. A ring centering portion is formed in a lower surface of the annular body and configured to center the moveable top ring on a moveable support ring.