Distributed Electrode Waveguide Layout for Uniform Plasma Fields
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The electric field in plasma chambers used for semiconductor fabrication is highly non-uniform, leading to variations in film deposition and etch uniformity across the surface of a wafer, particularly with higher frequency RF sources.
Innovation Solution
A system is implemented with multiple power signal inputs, utilizing dielectrics and circular waveguides with mode converters to distribute energy evenly to antennas in the plasma chamber, achieving circular polarization through phase-adjusted transverse mode signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the frequency of the RF source is increased to reduce film deposition or etch times, then productivity is improved, but the electric field becomes highly non-uniform leading to poor manufacturing precision
Solution Approach 1:
The patent divides the single antenna system into multiple distributed electrodes (N≥2) arranged in specific geometric patterns. Each electrode receives power signals through separate waveguides, allowing the system to maintain high frequency operation while distributing the electric field more uniformly across the wafer surface, thereby resolving the contradiction between productivity and manufacturing precision
Solution Approach 2:
The patent employs asymmetric geometric arrangements of distributed electrodes (such as triangular, rectangular, or hexagonal patterns with specific spacing ratios) to optimize electric field distribution. The asymmetric positioning and varying distances from the chamber center allow for improved field uniformity at high frequencies while maintaining productivity benefits
2Productivity
If the wavelength of the RF source decreases at higher frequencies, then productivity is improved, but the electric field uniformity deteriorates
Solution Approach 1:
The patent transitions from a single-point antenna excitation to a multi-point distributed electrode configuration, adding spatial dimensionality to the power distribution system. This dimensional expansion allows the electric field to be distributed more uniformly across the plasma chamber volume, compensating for the shortened wavelength effects at high frequencies while maintaining productivity
3Device complexity
If a single antenna is used to simplify the system, then device complexity is reduced, but electric field uniformity deteriorates
Solution Approach 1:
The patent combines multiple distributed electrodes into a coordinated system that functions as an integrated power distribution network. By merging the functions of multiple electrodes and waveguides into a unified configuration controlled by a single power source, the system achieves improved electric field uniformity without proportionally increasing operational complexity
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 approach enhances electric field uniformity in the plasma chamber, ensuring consistent film deposition and etch processes across the wafer surface.
Implementation Method 1
each of the N circular waveguides comprises a mode converter configured to convert a received first transverse mode signal to a second transverse mode signal to be output by the circular waveguide
Implementation Method 2
one or more dielectrics configured to distribute received energy to one or more antennas of a plasma chamber
Data Source
AI summary
In one embodiment, the present disclosure is directed to a system for providing improved electric field uniformity to a plasma chamber receiving multiple signal inputs. The system includes one or more dielectrics distributing received energy to one or more antennas. The one or more dielectrics have N receiving areas. N circular waveguides are positioned over the N receiving areas. Each of waveguides has a mode converter converting a received first transverse mode signal to a second transverse mode signal to be output by the circular waveguide to the corresponding receiving area.