Dual-Material Focus Ring for Plasma Etch Durability
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Solution Overview
Problem
Current focus rings used in semiconductor plasma etching processes face durability issues due to exposure to plasma, leading to reduced etching resistance and frequent replacement, which increases operational costs and reduces process efficiency.
Innovation Solution
A focus ring design featuring a first ring made of high etch-resistant material and a second ring made of a less expensive material, with a fastening member coupling them, allowing only the high etch-resistant first ring to be exposed to plasma, while the second ring remains protected and can be reused after the first ring is replaced.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a focus ring is made entirely of high etch-resistant material, then etching resistance is improved, but manufacturing cost increases
Solution Approach 1:
The focus ring is divided into two separate rings: a first ring made of high etch-resistant material (such as silicon carbide) and a second ring made of less expensive material (such as silicon). This segmentation allows each ring to have optimized material properties for its specific function while reducing overall manufacturing cost.
Solution Approach 2:
The first ring is specifically positioned to be exposed to plasma where high etching resistance is required, while the second ring is positioned to be protected from plasma exposure. This local quality approach applies different material properties only where needed, optimizing performance while reducing cost.
2Duration of action of stationary object
If a focus ring is made entirely of high etch-resistant material, then durability is improved, but operational cost increases
Solution Approach 1:
The focus ring is segmented into a first ring for plasma exposure and a second ring for structural support. This allows the expensive high etch-resistant material to be used only where durability is critical (in the first ring), reducing overall operational cost while maintaining durability where needed.
Solution Approach 2:
High etch-resistant material is applied locally only to the first ring that contacts plasma, while the second ring uses cheaper material. This local quality differentiation maintains durability in the plasma-exposed region while reducing operational costs overall.
3Reliability
If the first ring is replaced after plasma exposure, then etching resistance is maintained, but the second ring cannot be reused
Solution Approach 1:
The focus ring is designed as separable first and second rings, allowing the first ring to be replaced independently after plasma exposure while the second ring remains in place. This segmentation enables reuse of the second ring, extending the replacement cycle and reducing downtime.
Solution Approach 2:
The first ring is designed to be replaceable after plasma exposure, while the second ring is recovered and reused. This discarding and recovering approach reduces waste and extends the operational life of the focus ring assembly by reusing the protected second ring.
Data Source
AI summary
A focus ring and a method for manufacturing the same. The focus ring include a first ring made of a first material, a second ring covered by the first ring, wherein the second ring is made of a second material different from the first material, and a fastening member configured to couple the first ring to the second ring. The fastening member includes a through-part configured to pass through the second ring and a buried part buried in a lower portion of the first ring. The through-part has a first diameter, and the buried part has a second diameter greater than or equal to the first diameter.