Distributed Multi-Zone Plasma Source for Uniform Etching
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Solution Overview
Problem
Plasma reaction chambers suffer from center-to-edge non-uniformities in neutral species distribution, leading to inconsistent plasma processing results, particularly in dielectric etch applications, due to variations in gas flow velocity and residence time across the substrate.
Innovation Solution
A distributed multi-zone plasma source system featuring a ring plasma chamber with a primary winding and multiple ferrites, which concentrates a magnetic field to induce a secondary current and generate plasma, with outlets and inlets strategically placed to distribute plasma species uniformly across the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a typical parallel-plate capacitive plasma processing chamber is used, then plasma processing can be performed, but center-to-edge non-uniformities in neutral species distribution occur leading to inconsistent processing results
Solution Approach 1:
The plasma processing system is divided into multiple independent plasma sources arranged in an array, with each source serving a specific zone of the substrate. This segmentation allows independent control of plasma parameters in different regions, enabling uniform neutral species distribution across the entire substrate surface while eliminating the center-to-edge non-uniformities inherent in single-chamber systems.
2Productivity
If process gases are introduced across the width of the processing chamber, then plasma is formed, but variations in flow velocity and gas residence time cause non-uniform neutral species distribution
Solution Approach 1:
Each plasma source in the array is equipped with dedicated gas delivery systems that provide locally optimized gas flow rates and compositions tailored to the specific requirements of each substrate zone. This local quality approach ensures that each region receives the appropriate concentration and type of reactive species, compensating for variations in flow velocity and residence time that would otherwise cause non-uniform processing.
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 system achieves improved center-to-edge uniformity in plasma processing by evenly distributing plasma byproducts and recombination products, enhancing processing consistency and efficiency across the substrate.
Implementation Method 1
applying a primary current to a primary winding around an exterior of the ring plasma chamber, and generating a magnetic field with the primary winding. The ferrites concentrate the magnetic field
Implementation Method 2
A secondary current is induced in the process gas in the ring plasma chamber and a plasma is generated in the process gas in the ring plasma chamber with the secondary current
Implementation Method 3
A secondary current is induced in the process gas in the ring plasma chamber and a plasma is generated in the process gas in the ring plasma chamber with the secondary current
Data Source
AI summary
A plasma source includes a ring plasma chamber, a primary winding around an exterior of the ring plasma chamber and multiple ferrites, wherein the ring plasma chamber passes through each of the ferrites. A system and method for generating a plasma are also described.