Slit Valve Door Seal Hard Stop Gap Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional slit valve door seals in substrate processing systems are frequently contaminated by particulate byproducts, leading to premature replacement due to the attraction and flaking off of particles during the compression and decompression cycles, which results in substrate contamination.
Innovation Solution
A sealing apparatus with a flexible seal and a hard stop is used to fill the gap between the slit valve door and the substrate sealing surface, limiting the compression and decompression of the seal, thereby reducing exposure to particulate byproducts and extending the seal's lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the slit valve door and insert are made of metal and oriented with a gap between them, then metal particle formation is prevented, but the seal is exposed to particulate byproducts causing frequent replacement
Solution Approach 1:
The patent introduces a seal as an intermediary element between the slit valve door and the insert. This seal fills the gap between the two metal components, preventing direct contact and metal particle formation while maintaining the necessary sealing function. The seal acts as a mediator that protects the system from harmful metal particles.
Solution Approach 2:
The patent employs a flexible seal (elastomer material) that can deform to fill the gap between the slit valve door and insert. This flexible sealing element adapts to the interface geometry and maintains contact under varying conditions, providing both sealing and protection against particle generation.
2Reliability
If the seal is allowed to compress and decompress freely, then sealing function is maintained, but particulate byproducts flake off during compression cycles causing substrate contamination
Solution Approach 1:
The patent applies a coating to the seal surface that acts as a protective cushion against particulate accumulation. This pre-applied protective layer prevents particulates from directly bonding to the seal surface, reducing the likelihood of flaking during compression cycles and maintaining sealing reliability.
Solution Approach 2:
The patent modifies the surface properties of the seal through coating or treatment, changing parameters such as surface energy, roughness, or chemical composition. These parameter changes make the seal surface less attractive to particulate byproducts, preventing accumulation and subsequent flaking during operation.
3Object-affected harmful factors
If the gap between slit valve door and insert is reduced, then seal exposure to particulates is minimized, but manufacturing precision requirements increase
Solution Approach 1:
The patent divides the sealing function into separate components: the slit valve door, the insert, and the seal element. This segmentation allows each component to be manufactured with standard tolerances, while the assembled gap is controlled by the seal's compliance and the hard stop positioning, reducing the need for high-precision manufacturing of individual parts.
Solution Approach 2:
The flexible seal element compensates for variations in gap size caused by manufacturing tolerances. Its elasticity allows it to deform and maintain effective sealing across a range of gap dimensions, reducing the stringency of manufacturing precision requirements while still minimizing particulate exposure.
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 solution decreases the width of the gap between the slit valve door and the component, increasing the time for particulate byproducts to reach the seal, resulting in a 50% increase in the seal's life by minimizing exposure and flaking, thus reducing contamination and maintenance frequency.
Implementation Method 1
A compressible seal, made of an elastomer, may be used to fill a portion of the gap and to create an air tight seal between the slit valve door and the insert
Implementation Method 2
As the particulate byproducts are attracted to cooler surfaces, the particulate byproducts are attracted to, and may settle on, the slit valve door and exposed edge of the elastomer seal
Data Source
AI summary
Apparatus, methods and systems are provided for sealing the door of a slit valve. In one embodiment, the apparatus includes a seal, adapted to extend along a perimeter of a slit valve door; and a hard stop, disposed between the seal and an outer edge of the slit valve door, and adapted to extend along the length of the seal, wherein the hard stop and elastomer seal fill at least a portion of a gap between the slit valve door and an insert leading to a process chamber.