Multi-part Electrode for Plasma Reactor Wear Management
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Solution Overview
Problem
The existing semiconductor processing plasma reactors face challenges in maintaining uniform etching rates and electrode durability, particularly with the increasing size of wafers, as large single crystal silicon electrodes are costly and require frequent replacement due to wear, especially in large diameter configurations.
Innovation Solution
A multi-part upper electrode system with a removable central silicon element and surrounding segments, where the central element is designed for high wear and can be replaced independently of the outer segments, allowing for cost-effective and efficient maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a large diameter single crystal silicon electrode is used to process larger wafers, then wafer processing capacity increases, but electrode manufacturing cost and replacement frequency increase due to higher wear
Solution Approach 1:
The electrode is divided into a central replaceable element and outer segments. The central element experiences higher wear and can be replaced independently without replacing the entire electrode, thus extending the overall electrode life while maintaining the ability to process large wafers.
Solution Approach 2:
The highly worn central portion is extracted as a separate replaceable component. This allows the outer segments that experience less wear to continue being used, effectively extending the electrode's service life while maintaining productivity.
2Manufacturing precision
If a large diameter single crystal silicon electrode is used, then uniform etching across large wafers is achieved, but manufacturing cost increases due to difficulty in producing low impurity large diameter electrodes
Solution Approach 1:
The electrode is segmented into a central element and outer rings. The outer segments can be manufactured separately and may use different materials or structures optimized for their specific functional requirements, potentially reducing overall manufacturing cost while maintaining etching uniformity across the large wafer surface.
Solution Approach 2:
The electrode system uses different materials for different segments - the central element and outer segments can be made from different materials optimized for their specific roles, allowing cost-effective manufacturing while maintaining the precision required for uniform etching across large wafers.
3Manufacturing precision
If the entire electrode is replaced when the central portion wears, then etching uniformity is maintained, but replacement cost and downtime increase
Solution Approach 1:
The electrode is divided into a central replaceable element and outer segments. When the central element wears, only that portion needs to be replaced, not the entire electrode. This significantly reduces replacement time and cost while maintaining etching uniformity, as the outer segments that are still in good condition can remain in use.
Solution Approach 2:
The worn central portion is extracted and replaced independently. This allows the functional outer segments to continue operating, minimizing downtime and replacement costs while maintaining the precision required for uniform etching.
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 extends the life of the outer electrode segments by 2-3 times, reducing replacement costs and maintaining uniform etching rates across larger wafer sizes, as the central electrode can be replaced more frequently than the outer segments, thus addressing the wear issues and scalability challenges.
Implementation Method 1
The electric field established between the grounded electrode and the RF electrode will dissociate the reactive gas forming a plasma
Implementation Method 2
a plasma is formed above the masked surface of the wafer by adding large amounts of energy to a gas at relatively low pressure, resulting in ionizing the gas
Implementation Method 3
The electric field created by the electrodes will attract the ions to the wafer, causing the ions to strike the surface in a predominantly vertical direction
Implementation Method 4
reactive ion etching combines the energetic etching effects of the plasma with the chemical etching effect of the gas
Implementation Method 5
The surface of the wafer is etched by chemical interaction with the active ions and by momentum transfer of the ions striking the surface of the wafer
Data Source
AI summary
An improved upper electrode system has a multi-part electrode in which a central portion of the electrode having high wear is replaceable independent of an outer peripheral portion of the electrode. The upper electrode can be used in plasma processing systems for processing semiconductor substrates, such as by etching or CVD. The multi-part upper electrode system is particularly useful for large size wafer processing chambers, such as 300 mm wafer processing chambers for which monolithic electrodes are unavailable or costly.