Edge Ring Electrode Plasma Sheath Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the semiconductor manufacturing industry, the decreasing feature size and increasing complexity of transistor structures lead to yield issues such as contact via misalignment and poor selectivity at the substrate edge, primarily due to the bending of the plasma sheath near the substrate edge.
Innovation Solution
A substrate support system with an electrostatic chuck, an edge ring assembly, and silicon rings is used to control the plasma sheath near the substrate edge, featuring a power distribution assembly in direct electrical contact with the edge ring electrode to adjust the plasma sheath and improve processing uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the plasma sheath is used for substrate processing, then processing capability is achieved, but plasma sheath bending at the substrate edge causes yield issues such as contact via misalignment and poor selectivity
Solution Approach 1:
The patent applies local quality by introducing an edge ring electrode specifically at the substrate edge region, distinct from the main chucking electrode. This localized electrode structure enables independent control of plasma sheath characteristics at the edge versus the center, allowing correction of edge-specific bending issues without affecting overall processing. The edge ring electrode creates a localized electric field that counteracts the plasma sheath bending phenomenon specifically where it occurs.
Solution Approach 2:
The patent utilizes parameter changes by adjusting the voltage applied to the edge ring electrode to modify plasma sheath properties. By varying the electrical potential at the edge ring electrode, the plasma sheath thickness, shape, and density can be dynamically controlled to prevent bending. This parameter adjustment enables real-time optimization of plasma characteristics to maintain vertical sheath geometry and improve manufacturing precision.
2Manufacturing precision
If fine, localized process tuning is implemented at the substrate edge, then processing uniformity is improved, but device complexity increases due to additional edge ring assembly components
Solution Approach 1:
The patent applies segmentation by dividing the electrode system into distinct functional zones: the main chucking electrode for bulk substrate processing and the separate edge ring electrode for edge-specific control. This segmentation allows independent optimization of each region's processing parameters, achieving uniformity across the entire substrate including the edge, while keeping each component's design relatively simple and modular.
Solution Approach 2:
The edge ring assembly, while adding components, serves multiple functions: it provides localized plasma control, acts as a structural support for the substrate edge, and can be integrated with the existing chucking mechanism. This multi-functionality justifies the added complexity by delivering multiple benefits from a single integrated assembly rather than requiring separate systems for each function.
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
This solution allows for fine, localized process tuning at the substrate edge, enhancing processing uniformity and reducing yield issues, while maintaining uniformity across the substrate surface.
Implementation Method 1
adjusting the plasma sheath within the processing chamber with the edge ring electrode
Implementation Method 2
an electrostatic chuck with a chucking electrode
Data Source
AI summary
The present disclosure generally relates to apparatuses and methods for controlling a plasma sheath near a substrate edge. The apparatus relates to a processing chamber and/or a substrate support that includes an edge ring assembly with an edge ring electrode and an electrostatic chuck with a chucking electrode. The edge ring assembly is positioned adjacent the electrostatic chuck, such as with the edge ring assembly positioned exterior to or about the electrostatic chuck. The edge ring assembly includes a base and a cap positioned above the base with the edge ring electrode positioned between the cap and the base. The base of the edge ring electrode may include an inner recess and/or an outer recess with the cap including one or more lips that extend into the inner recess and/or the outer recess. One or more silicon rings and/or insulating rings are positioned adjacent the edge ring assembly.