Substrate Support Contact Geometry for Uniform Plasma Heating
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Solution Overview
Problem
Existing plasma processing apparatuses face challenges in achieving uniform substrate temperature distribution due to heat generation at contact points during current flow, leading to non-uniform temperature distribution.
Innovation Solution
The substrate support design includes contact pins with a tapered shape, where the area of the surface coupled to the electrode is greater than the area coupled to the power supply line, reducing electric resistance and heat emission, and bias electrodes are strategically placed to suppress discharge and improve temperature uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cylindrical contact structure is used to electrically couple the electrode and power supply line, then electrical connection is achieved, but heat is generated at the contact portion resulting in non-uniform substrate temperature distribution
Solution Approach 1:
The contact structure is designed with non-uniform cross-sectional area along its length. The first portion (contacting electrode) has a larger cross-sectional area than the second portion (contacting power supply line), creating localized differences in electrical resistance and heat generation. This local quality variation ensures that heat is concentrated in the lower portion away from the substrate, while the substrate-contacting portion remains cooler and more uniform in temperature.
2Ease of manufacture
If the contact structure has equal surface areas at both ends, then manufacturing is simplified, but heat generation at contact points causes temperature non-uniformity
Solution Approach 1:
The contact structure deliberately employs asymmetric geometry with different cross-sectional areas at its two ends. The first portion has a larger cross-sectional area than the second portion, creating an asymmetric design that optimizes heat management. This asymmetry allows the structure to function more effectively by concentrating heat generation in the lower portion while maintaining better thermal conditions at the substrate interface, thereby improving temperature distribution control despite increased manufacturing 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 design enhances in-plane uniformity of substrate temperature by minimizing heat generation and emission at contact points, thereby improving temperature control during plasma processing.
Implementation Method 1
When a current flows through the power supply terminal, heat is generated at a contact portion
Implementation Method 2
an area of a surface of each of the power supply terminals that is coupled to the electrode is greater than an area of a surface of each of the power supply terminals that is coupled to the power supply line
Data Source
AI summary
A substrate support includes a substrate supporting surface, an electrode, a power supply line, and a power supply terminal. The electrode is disposed below the substrate supporting surface and configured to provide a bias power. The power supply line is disposed below the electrode and configured to apply the bias power to the electrode. The power supply terminal is configured to electrically couple the electrode and the power supply line. Further, an area of a surface of the power supply terminal that is coupled to the electrode is greater than an area of a surface of the power supply terminal that is coupled to the power supply line.