Rotatable Edge Ring Structure for Plasma Sheath Control
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in controlling the plasma sheath in the edge region of substrates due to the inability to adjust the shape of the edge ring, leading to contamination from accumulated byproducts.
Innovation Solution
An edge ring design featuring an outer ring, an inner ring, outer and inner uneven portions, a supporting ring, and a rotation module, allowing for the selective rotation of the inner ring to control the plasma sheath by adjusting the overlap ratios between the uneven portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the edge ring shape is fixed after installation, then the device structure is simple, but the plasma sheath in the edge region cannot be controlled
Solution Approach 1:
The inner ring is made rotatable relative to the outer ring, transforming the static edge ring structure into a dynamic one. The rotation module enables the inner ring to rotate around the center point of the outer ring, allowing the uneven portions to change their overlap ratios and thereby control the plasma sheath shape in the edge region of the substrate.
2Ease of operation
If the edge ring shape cannot be changed, then the device structure is simple, but byproducts accumulate on the edge ring
Solution Approach 1:
The rotatable inner ring creates variable spacing between uneven portions through rotation, forming discharge channels that enable byproducts to be expelled from the edge ring structure.
3Object-affected harmful factors
If the edge ring shape cannot be changed, then the device structure is simple, but the substrate is contaminated by byproducts
Solution Approach 1:
By rotating the inner ring to adjust the overlap ratio of uneven portions, the system dynamically opens discharge channels that vent byproducts away from the substrate, preventing contamination.
4Manufacturing precision
If the inner ring is made rotatable, then the plasma sheath can be controlled, but the device complexity increases
Solution Approach 1:
The edge ring is segmented into an outer ring and a rotatable inner ring, with uneven portions on each ring that can be independently positioned through rotation to control plasma sheath shape.
Solution Approach 2:
The rotation module provides dynamic control of the inner ring's angular position, enabling precise adjustment of the overlap ratio between uneven portions to achieve desired plasma sheath shapes.
Data Source
AI summary
A system is described for protecting the edge region of a substrate during a plasma process. The system includes an outer ring with a plurality of outer uneven portions and an inner ring also with a plurality of inner uneven portions. The outer ring covers the edge region of the substrate. The inner ring may rotate around the center point of the outer ring. When the inner ring is rotated, each of the inner uneven portions and each the outer uneven portions may slide by each other to overlap and to form openings. Changes of the opening ratios in the gaps (or the overlap ratios of the inner and outer uneven portions) may change a thickness of a plasma sheath. Thus, the plasma sheath in an edge region of the substrate may be readily controlled.