Variable Geometry Process Kit for Semiconductor Edge Uniformity
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Solution Overview
Problem
Semiconductor processing in process chambers often experiences non-uniformities at the perimeter edge of substrates due to electric field termination effects, which are not adequately addressed by conventional deposition and etching rings that have different profiles and positions for each process.
Innovation Solution
A process kit with a variable geometry configuration, including an annular body, first and second rings with downwardly directed projections, and an annular shield, that adjusts its position in response to substrate support displacement to maintain uniform electric fields during both deposition and etching processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate deposition rings and etching rings with different profiles and positions are used for each process, then the process performance for each specific process is optimized, but the device complexity increases and cannot accommodate rapid succession processes
Solution Approach 1:
The patent applies universality by designing a single ring structure that can serve both as a deposition ring and an etching ring. The ring includes a body portion and a lip portion that can be positioned at different heights relative to the substrate support surface, allowing it to function optimally for both deposition and etching processes without requiring separate specialized rings for each process type.
Solution Approach 2:
The patent applies dynamics by making the ring structure adjustable or reconfigurable. The lip portion can be positioned at different heights (first height for deposition, second height for etching) relative to the substrate support surface, enabling the same ring to adapt its geometry to optimize performance for different process types in rapid succession.
2Productivity
If a single ring structure is used for both deposition and etching processes, then the device complexity is reduced and rapid succession processes are enabled, but the ability to optimize process-specific parameters is limited
Solution Approach 1:
The patent resolves this contradiction by implementing a dynamic ring structure where the lip portion can be repositioned between a first height for deposition optimization and a second height for etching optimization. This dynamic adjustment capability allows the single ring structure to maintain high productivity while achieving process-specific optimization for both deposition and etching operations.
Solution Approach 2:
The patent applies parameter changes by varying the height of the lip portion relative to the substrate support surface depending on the process type. For deposition, the lip is positioned at a first height to optimize deposition uniformity, while for etching, it is positioned at a second height to optimize etching uniformity, thereby enabling a single ring structure to achieve process-specific parameter optimization.
3Manufacturing precision
If conventional deposition and etching rings are used, then each process has its dedicated optimized configuration, but edge effects causing non-uniformities at the substrate perimeter are not adequately addressed
Solution Approach 1:
The patent applies local quality by designing the ring with a specific lip portion that interacts with the substrate perimeter region. The lip is configured to locally modify the electric field distribution at the substrate edge, thereby addressing edge effects and improving uniformity specifically at the problematic perimeter regions while maintaining overall process performance.
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 process kit reduces non-uniformities by modifying the edge geometry, achieving more uniform deposition and etching rates across the substrate, enhancing performance in both processes over conventional kits.
Implementation Method 1
non-uniformities at the perimeter edge of substrates due to electric field termination effects
Data Source
AI summary
Variable geometry process kits for use in semiconductor process chambers have been provided herein. In some embodiments, a process kit for use in a semiconductor process chamber includes: an annular body configured to rest about a periphery of a substrate support; a first ring positioned coaxially with the annular body and supported by the annular body; a second ring positioned coaxially with the first ring and supported by the first ring; and an annular shield comprising a horizontal leg positioned coaxially with the second ring such that a portion of the horizontal leg is aligned with and below portions of the first ring and second ring.