Composite Edge Ring for Plasma Processing Gas Leakage
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Solution Overview
Problem
The existing edge rings in plasma processing, particularly those made of silicon carbide, experience increased heat transfer gas leakage and particle generation due to reduced electrostatic attraction and the formation of reaction products at material boundaries, necessitating frequent replacements.
Innovation Solution
An edge ring configuration featuring a first member made of a high plasma resistance material and a second member with lower rigidity, bonded together with an adhesive layer, includes inclined portions to enhance electrostatic attraction and reduce reaction product adhesion, thereby minimizing gas leakage and particle generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single-material edge ring is used, then manufacturing is simplified, but reaction products form at material boundaries causing particle generation
Solution Approach 1:
The edge ring uses a composite structure of SiC and Si members bonded together. The Si member serves as a transition layer that prevents direct contact between the SiC edge ring and the substrate, eliminating the formation of harmful reaction products at the interface while maintaining manufacturing feasibility through adhesive bonding.
2Stability of the object's composition
If the edge ring has high rigidity, then structural stability is improved, but heat transfer gas leakage increases due to reduced followability to the electrostatic chuck
Solution Approach 1:
The edge ring combines a rigid SiC first member for structural stability with a more flexible Si second member that has better followability to the electrostatic chuck surface. This composite structure allows the edge ring to maintain its shape while adapting to the chuck surface, preventing heat transfer gas leakage.
Solution Approach 2:
Different portions of the edge ring have different material properties: the SiC first member provides rigidity and plasma resistance, while the Si second member provides flexibility and electrostatic adhesion. This local differentiation of material properties allows the edge ring to simultaneously achieve structural stability and surface followability.
3Object-generated harmful factors
If frequent edge ring replacement is performed, then particle generation is reduced, but productivity decreases due to processing interruptions
Solution Approach 1:
The composite structure of SiC and Si members eliminates the formation of reaction products at material boundaries, which is the root cause of particle generation. This design allows the edge ring to maintain low particle generation over extended periods, reducing replacement frequency and improving productivity.
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 configuration reduces the frequency of edge ring replacements, suppresses heat transfer gas leakage, and effectively minimizes particle generation during plasma processing.
Implementation Method 1
The plasma processing upon the substrate is performed in the state that the substrate and the edge ring disposed on an electrostatic chuck are attracted to and held by the electrostatic chuck by an electrostatic attraction force.
Implementation Method 2
In order to improve a heat transfer between the substrate and the electrostatic chuck and a heat transfer between the edge ring and the electrostatic chuck, a heat transfer gas such as a He gas is supplied into a gap between the electrostatic chuck and the substrate and into a gap between the electrostatic chuck and the edge ring.
Data Source
AI summary
An edge ring disposed around a processing target substrate includes a first member of an annular shape, which is made of a first material and has a first inclined portion at a lower portion of an inner peripheral side surface thereof; and a second member of an annular shape, which is made of a second material different from the first material and has a second inclined portion facing the first inclined portion, the second member being provided under the first member.