Segmented Process Kit Rings for Polymer Exhaustion
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Solution Overview
Problem
During substrate processing, such as semiconductor and display panel etching, non-uniform plasma distribution leads to polymer material accumulation at the edge of the substrate, which can stick to the process kit ring and electrostatic chuck, causing poor processing results and yield.
Innovation Solution
A substrate support assembly with an electrostatic chuck and a process kit featuring concentric inner and outer rings, where the outer ring includes pumping channels angled downward to efficiently remove unwanted polymer material from the substrate support surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If edge rings are used to increase plasma uniformity, then plasma distribution is improved, but polymer material accumulates at the substrate edge and sticks to the process kit ring
Solution Approach 1:
The process kit ring is divided into an inner ring and an outer ring with a gap between them. This segmentation allows polymer material to be removed from the gap region, preventing accumulation and re-deposition on the substrate while maintaining the plasma uniformity enhancement function of the edge rings.
Solution Approach 2:
The harmful polymer accumulation is extracted by creating a gap between the inner and outer rings. This gap serves as a removal zone where polymer material can be evacuated, separating the plasma enhancement function from the polymer accumulation problem.
2Manufacturing precision
If polymer material accumulates at the substrate edge, then processing quality deteriorates, but maintenance time increases
Solution Approach 1:
The gap structure is designed in advance to prevent polymer accumulation before it affects processing quality. By providing a dedicated removal zone, the system proactively manages polymer material, preventing the need for frequent maintenance interventions.
Solution Approach 2:
The gap between the inner and outer rings enables self-cleaning functionality. Polymer material that accumulates during processing is automatically removed through the gap, allowing the system to maintain itself without external intervention and reducing maintenance requirements.
3Productivity
If the process kit ring is used to improve plasma distribution, then yield is improved, but polymer material diffuses into the electrostatic chuck
Solution Approach 1:
Dividing the process kit ring into segmented inner and outer rings creates a controlled gap that manages polymer material flow. This segmentation prevents uncontrolled diffusion into the electrostatic chuck while preserving the yield-improving plasma distribution benefits.
Solution Approach 2:
The gap between the inner and outer rings acts as an intermediary zone that mediates polymer material management. It provides a controlled pathway for polymer removal, preventing direct diffusion into the electrostatic chuck while maintaining the functional benefits of the process kit ring.
Data Source
AI summary
Implementations of the present disclosure provide a process kit for an electrostatic chuck. In one implementation, a substrate support assembly is provided. The substrate support assembly includes an electrostatic chuck having a first recess formed in an upper portion of the electrostatic chuck. A process kit surrounds the electrostatic chuck. The process kit includes an inner ring and an outer ring disposed radially outward of the inner ring. The outer ring includes a second recess formed in an upper portion of the upper ring. The inner ring is positioned within and is supported by the first recess and the second recess. An upper surface of the inner ring and an upper surface of the outer ring are co-planar.