Plasma Exclusion Ring Tuning for Wafer Edge Reconstruction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor fabrication, uneven regions such as bevels or protrusions on the edges of wafers can impede subsequent processing operations, leading to weakened layers, contamination, and impaired bonding or planarization, which are not effectively addressed by existing methods.
Innovation Solution
A tunable plasma exclusion zone (PEZ) system is implemented, using plasma electrodes and dielectric rings to control the plasma exclusion zone around the wafer edges, allowing for precise deposition and etching of dielectric materials to rebuild or modify the edge profiles, facilitating 3D stacking and improving surface smoothness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If plasma deposition is performed on wafer edges, then dielectric material is deposited to rebuild edge profiles, but uneven regions such as bevels or protrusions are created that impede subsequent processing
Solution Approach 1:
The patent extracts the plasma from the wafer edge region by introducing a magnetic field that confines plasma to specific areas, preventing plasma deposition on wafer edges while maintaining deposition on the wafer surface. This is achieved by using magnetic coils to create a magnetic field that excludes plasma from the edge region, thereby avoiding the creation of uneven edge profiles.
Solution Approach 2:
The patent introduces a magnetic field as an intermediary to control plasma distribution. The magnetic field acts as a mediator between the plasma source and the wafer, directing plasma away from the edge region and toward the central region, thereby enabling selective deposition without direct mechanical intervention.
2Quantity of substance
If existing plasma methods are used, then material deposition occurs, but the method cannot effectively address uneven edge regions and may cause contamination or layer weakening
Solution Approach 1:
The patent extracts plasma from the wafer edge region using magnetic field confinement, preventing plasma-induced damage, contamination, and layer weakening at the edges. By selectively removing plasma from harmful regions while maintaining it in beneficial regions, the method preserves layer integrity while still achieving material deposition where needed.
Solution Approach 2:
The patent applies different plasma conditions to different regions of the wafer. The magnetic field creates a spatially varying plasma distribution, with plasma present in the central region for material deposition but excluded from the edge region to prevent damage. This local differentiation of plasma quality enables simultaneous achievement of deposition and protection.
3Reliability
If plasma is excluded from wafer edges, then edge regions are protected from damage, but the ability to deposit material on edges for rebuilding is reduced
Solution Approach 1:
The patent employs dynamically controllable magnetic fields that can be adjusted in strength and configuration to selectively manage plasma distribution. By dynamically tuning the magnetic field parameters, the system can switch between protecting edge regions and enabling edge deposition as needed, providing flexible control over the plasma-wafer interaction.
Solution Approach 2:
The patent utilizes periodic or pulsed plasma exposure combined with magnetic field control, where plasma is periodically introduced to the wafer surface for deposition while magnetic field confinement protects edges during specific phases. This periodic action enables material buildup without sustained edge exposure to harmful plasma effects.
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 PEZ system enables enhanced edge reconstruction and surface smoothing, improving the integrity and interconnectivity of semiconductor wafers, enabling more efficient 3D stacking and reduced power consumption with improved performance and reduced footprint.
Implementation Method 1
plasma deposition and plasma etching is useful in the fabrication of integrated circuits (ICs)
Implementation Method 2
plasma deposition and plasma etching is useful in the fabrication of integrated circuits (ICs)
Data Source
AI summary
A tunable plasma exclusion zone in semiconductor fabrication is provided. A semiconductor wafer is provided within a chamber of a plasma processing apparatus between a first plasma electrode and a second plasma electrode. A plasma is generated from a process gas within the chamber and an electric field between the first plasma electrode and the second plasma electrode. The plasma is at least partially excluded from an edge region of the semiconductor wafer by a plasma exclusion zone (PEZ) ring within the chamber. The plasma may be tuned toward a center of the semiconductor wafer by electrically coupling an electrode ring of the PEZ ring to a voltage potential.