Electrostatic Chuck RF Mesh Layout for Edge Plasma Uniformity
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Solution Overview
Problem
Current semiconductor manufacturing processes face challenges in achieving fine, localized process tuning at the edge of the substrate, particularly in controlling plasma uniformity and addressing yield issues such as contact via misalignment and poor selectivity to a hard mask.
Innovation Solution
The implementation of a semiconductor processing chamber with a substrate support assembly featuring a first and a second radio frequency power source, embedded electrodes, and a power splitter to adjust RF power distribution, allowing for precise control of plasma near the substrate edge through a capacitive or resonance-based voltage divider.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single RF power source is used for the substrate support assembly, then the device complexity is reduced, but the manufacturing precision and plasma uniformity at the substrate edge deteriorate
Solution Approach 1:
The substrate support assembly is segmented into multiple independent RF-powered electrodes: a central electrode and an annular electrode. Each electrode can be independently controlled by separate RF power sources, allowing localized plasma tuning at the substrate edge while maintaining overall plasma uniformity across the substrate surface.
Solution Approach 2:
Different regions of the substrate support assembly are assigned different RF power characteristics. The central electrode and annular electrode receive different RF power levels and frequencies, enabling localized control of plasma properties at the substrate edge without affecting the entire substrate uniformly, thus improving edge plasma uniformity while managing device complexity.
2Manufacturing precision
If multiple RF power sources are used for central and annular electrodes, then the plasma uniformity and process control are improved, but the device complexity and cost increase
Solution Approach 1:
The system incorporates dynamic control capabilities where RF power sources can independently adjust power levels, frequencies, and phases to central and annular electrodes in real-time. This dynamic adjustment allows optimization of plasma uniformity and process control while managing device complexity through adaptive rather than static configurations.
Solution Approach 2:
Multiple RF power sources enable independent variation of critical parameters including power level, frequency, and phase for each electrode. By changing these parameters dynamically, the system achieves superior plasma uniformity and process control at the substrate edge while avoiding the need for complex hardware modifications to the fundamental chamber structure.
3Manufacturing precision
If RF power is increased to improve plasma uniformity, then the deposition rate and film quality improve, but the risk of plasma non-uniformity and process instability increases
Solution Approach 1:
The system incorporates feedback control mechanisms where plasma parameters are continuously monitored and RF power to central and annular electrodes is dynamically adjusted in response. This feedback loop maintains plasma uniformity and process stability even at higher power levels, preventing plasma instabilities while achieving improved film deposition rates and quality.
Solution Approach 2:
The central and annular electrodes provide counterbalancing RF power distribution that compensates for plasma non-uniformities. By applying RF power in a balanced manner across different electrode regions, the system counteracts potential plasma instabilities and maintains reliable, stable processing conditions while achieving high deposition rates and superior film parameters.
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
Enhances plasma uniformity across the substrate, improving film parameters like deposition rate, film stress, and refractive index without requiring hardware changes, thus optimizing plasma profiles for multiple film deposition processes.
Implementation Method 1
providing a first radio frequency power to a central electrode embedded in a substrate support assembly, providing a second radio frequency power to an annular electrode embedded in the substrate support assembly
Implementation Method 2
Electrostatic chuck with multiple radio frequency meshes to control plasma uniformity
Data Source
AI summary
The present disclosure relates to a method and apparatus for controlling a plasma sheath near a substrate edge. Changing the voltage/current distribution across the inner electrode and the outer electrode with in the substrate assembly facilitates the spatial distribution of the plasma across the substrate. The method includes providing a first radio frequency power to a central electrode embedded in a substrate support assembly, providing a second radio frequency power to an annular electrode embedded in the substrate support assembly at a location different than the central electrode, wherein the annular electrode circumferentially surrounds the central electrode, monitoring parameters of the first and second radio frequency power, and adjusting one or both of the first and second radio frequency power based on the monitored parameters.