Interlocking Composite Seal for UHV Process Chambers
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Solution Overview
Problem
Existing semiconductor process chamber seals face challenges in maintaining ultra-high-vacuum and ultra-high-purity environments due to inefficient sealing, equipment downtime, and particle generation, largely because prior art designs lack effective interlocking mechanisms and are prone to degradation from plasma and thermal exposure.
Innovation Solution
A seal comprising a first elastomeric seal element with a protrusion and a second polymeric seal element with a recess, where the protrusion and recess interlock to energize the sealing surfaces during compression, preventing separation and rotation, and the polymeric element shields the elastomeric element from plasma and thermal exposure, allowing for efficient sealing in ultra-high-vacuum and ultra-high-purity environments without compromising cleanliness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If prior art seal designs are used with elastomeric and polymeric sealing elements, then sealing function is provided, but the sealing performance is insufficient and the seal elements separate or rotate under compression
Solution Approach 1:
The seal is divided into two distinct sealing elements: a first elastomeric sealing element and a second polymeric sealing element. Each element performs a specific sealing function, with the first element providing initial sealing and the second element providing enhanced sealing under compression. This segmentation allows each element to be optimized for its specific function while working together to solve the overall sealing performance issue.
Solution Approach 2:
The first elastomeric sealing element is positioned within a groove that contains the second polymeric sealing element. The protrusion of the first element extends into the recess of the second element, creating a nested configuration where the elements interlock. This nesting arrangement ensures proper positioning and prevents separation or rotation under compression, directly addressing the reliability issue.
2Reliability
If the polymeric sealing element is exposed to plasma and thermal conditions, then sealing function is maintained, but the elastomeric element degrades rapidly
Solution Approach 1:
The second polymeric sealing element acts as an intermediary protective layer between the plasma/thermal environment and the first elastomeric sealing element. The polymeric material is positioned to shield the elastomeric element from direct exposure to harmful plasma and thermal conditions, while still maintaining the sealing function. This intermediary arrangement significantly reduces degradation of the elastomeric element.
Solution Approach 2:
The seal combines two different materials with complementary properties: an elastomeric material providing flexibility and initial sealing, and a polymeric material providing resistance to plasma and thermal degradation. This composite structure allows the seal to withstand harsh processing conditions while maintaining durability and sealing performance over time.
3Device complexity
If traditional seal designs without interlocking mechanisms are used, then device complexity is reduced, but separation and rotation of seal elements occur under compression
Solution Approach 1:
The seal is divided into two distinct sealing elements: a first elastomeric sealing element and a second polymeric sealing element. Each element performs a specific sealing function, with the first element providing initial sealing and the second element providing enhanced sealing under compression. This segmentation allows each element to be optimized for its specific function while working together to solve the overall sealing performance issue.
Solution Approach 2:
The first elastomeric sealing element is positioned within a groove that contains the second polymeric sealing element. The protrusion of the first element extends into the recess of the second element, creating a nested configuration where the elements interlock. This nesting arrangement ensures proper positioning and prevents separation or rotation under compression, directly addressing the reliability issue.
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 interlocking seal design enhances sealing performance, maintains vacuum integrity, reduces equipment downtime, and minimizes particle generation, enabling efficient operation in UHV and UHP environments with a clamped interface.
Implementation Method 1
The elastomeric seal element creates a seal during early evacuation stages, with the help of a clamping device
Implementation Method 2
The polymeric seal element shields the elastomeric seal element from gas permeation, thermal exposure, and reactive plasmas
Data Source
AI summary
A seal for sealing an interface between a container and a lid of a process chamber. The seal comprises a first seal element and a second seal element that are arranged to seal the interface in series, with the second seal element being situated to encounter processing activity upstream of the fist seal element. The first seal element has a deflectable portion and a protrusion extending radially from the deflectable portion. The second seal element has a radially extending recess in which the protrusion of the first seal element is received. The protrusion and recess interlock to restrict separation and/or rotation of the first and second seal elements. Inclined surfaces of the first seal element interact with the second seal element to apply axial sealing forces to sealing surfaces of the second seal member.