Lower PEZ Ring for Bevel Etcher Plasma Control
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Solution Overview
Problem
Existing semiconductor substrate bevel edge cleaning technologies face challenges in accurately controlling the extent of edge exclusions during plasma etching, leading to contamination and increased costs due to the need for frequent replacement of consumable components and difficulty in maintaining precise plasma control.
Innovation Solution
A plasma processing apparatus with configurable plasma-exclusion-zone (PEZ) rings that shield specific areas from plasma, allowing for precise control of the bevel edge cleaning process by varying the outer diameter of the PEZ rings and using RF power to energize process gases, thereby minimizing contamination and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If plasma is used to clean the bevel edge, then the byproduct layer is removed, but the plasma may damage the dielectric layer above the apex
Solution Approach 1:
The dielectric layer is segmented into two functional zones: a first portion above the apex that serves as a mask and a second portion below the apex that is cleaned by plasma. The PEZ ring further segments the plasma exposure zone, creating a sharp boundary that protects the upper dielectric while enabling cleaning of the lower bevel edge. This segmentation allows selective plasma exposure without damaging the mask layer.
Solution Approach 2:
The plasma exclusion zone (PEZ) ring acts as an intermediary component between the plasma source and the dielectric layer. It creates a controlled boundary that directs plasma exposure to specific regions (below the apex) while blocking plasma from reaching protected regions (above the apex). This intermediary structure enables precise spatial control of plasma damage.
2Manufacturing precision
If the PEZ ring outer diameter is reduced to improve plasma control, then the plasma exclusion zone is improved, but the manufacturing complexity increases
Solution Approach 1:
The system enables dynamic adjustment of the PEZ ring outer diameter parameter to optimize plasma exclusion for different wafer sizes and cleaning requirements. By making this geometric parameter configurable, the system achieves precise plasma control without requiring complex mechanical structures. The parameter can be changed by selecting different PEZ ring components with appropriate outer diameters.
Solution Approach 2:
The PEZ ring is designed as a universal component that serves multiple functions: it defines the plasma exclusion zone boundary, protects the dielectric mask layer, and can be configured for different wafer sizes. This multi-functionality reduces the need for multiple specialized components, thereby reducing overall system complexity while maintaining precise plasma control.
3Productivity
If byproduct layers accumulate on the bevel edge, then the etch process continues, but the bonds weaken and layers peel off causing contamination
Solution Approach 1:
The system performs preliminary cleaning of the bevel edge by removing accumulated byproduct layers before they can peel off and contaminate other substrates. The plasma cleaning process is applied in advance during the etch process to maintain the bevel edge in a clean state, preventing the harmful peeling effect before it occurs.
Solution Approach 2:
The plasma cleaning action is applied continuously during the etch process to maintain the bevel edge free of accumulating byproduct layers. This continuous useful action prevents the cyclic accumulation and peeling phenomenon, ensuring that the protective dielectric layer remains bonded and no contamination is generated throughout the entire processing sequence.
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 solution enables precise control over the bevel edge cleaning process, reducing contamination and costs by allowing for customizable PEZ ring configurations and efficient plasma management, resulting in improved process yield and reduced consumable replacement frequencies.
Implementation Method 1
A process gas is introduced into the reaction chamber and energized into a plasma. The bevel edge is cleaned with the plasma so as to remove the layer below the apex
Implementation Method 2
At least one radio frequency (RF) power source is adapted to energize process gas into the plasma during a cleaning operation
Implementation Method 3
The lower and upper PEZ rings are adapted to respectively shield the lower support and the upper dielectric component from the plasma during the cleaning operation
Data Source
AI summary
A lower plasma-exclusion-zone ring for a bevel etcher is provided that is configured to etch a bevel edge of a substrate. The lower plasma-exclusion-zone ring includes a ring-shaped body and a radially-outer stepped surface. The ring-shaped body of the lower plasma-exclusion-zone ring defines an upper surface, a lower surface, a radially inner surface, and a radially outer surface. The radially-outer stepped surface of the lower plasma-exclusion-zone ring extending inwardly into the ring-shaped body between the radially outer surface of the ring-shaped body and the upper surface of the ring-shaped body. The ring-shaped body is made of a material selected from a group consisting of aluminum oxide, aluminum nitride, silicon, silicon carbide, silicon nitride, and yttria.