Reticle Container Tapered-Corner Latching to Reduce Particle Generation
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Solution Overview
Problem
The generation of particles due to friction between the inner pod cover and base plate in mask carriers during opening and closing, which can damage masks or blank substrates and cause image errors in photolithography processes.
Innovation Solution
A novel configuration of the mask inner pod with tapered corners, ball-shaped members, and biasing members to prevent direct contact and friction between the cover and base plate, using polymer-coated aluminum alloy materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the inner pod cover and base plate are made of metal materials (aluminum alloy with nickel, chromium coatings) to enhance mechanical properties and control weight, then the strength and durability are improved, but friction between the surfaces generates metal particles that contaminate the mask and cause image errors
Solution Approach 1:
A polymer coating layer is introduced as an intermediary between the metal base plate and the metal cover. This coating layer prevents direct metal-to-metal contact during opening and closing operations, thereby eliminating particle generation while maintaining the mechanical strength of the underlying metal structure.
Solution Approach 2:
The inner pod base plate and cover are constructed as composite structures combining metal substrates (aluminum alloy) with polymer coating layers. This composite approach provides both the mechanical strength required for the container and the particle-free surface contact needed to protect the mask.
2Manufacturing precision
If the inner pod cover and base plate are designed to fit each other with high accuracy to ensure proper closure, then the sealing and protection are improved, but positional inaccuracy or dimensional inaccuracy causes contact and friction between the surfaces
Solution Approach 1:
The polymer coating serves as a mediator that accommodates minor positional and dimensional inaccuracies between the cover and base plate. This compliant layer allows the components to fit together adequately without generating friction, even when precision tolerances are not perfectly met.
3Object-generated harmful factors
If the inner pod cover and base plate are made of polymer materials to reduce friction and particle generation, then the particle contamination is reduced, but the mechanical strength and weight control are compromised
Solution Approach 1:
The solution uses composite materials where a polymer coating is applied over a metal substrate. The metal base plate provides the necessary mechanical strength and weight control, while the polymer coating layer provides the low-friction, particle-free surface contact needed to protect the mask.
4Object-generated harmful factors
If the inner pod cover and base plate are made of polymer materials to prevent friction, then particle generation is avoided, but the structural durability and reliability are reduced
Solution Approach 1:
The inner pod components use composite construction with metal substrates providing structural durability and reliability, combined with polymer coating layers that prevent particle generation. This hybrid approach ensures both structural integrity and mask protection.
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
Reduces particulate contamination and image errors, lowering the cost of defect checking and enhancing the reliability of mask transportation and storage.
Implementation Method 1
a ball-shaped member and a biasing member located in the tapered corners of the base, and a recess located in the tapered corners of the cover. The ball-shaped member mates with the recess when the cover is attached to the base
Data Source
AI summary
A mask container for storing a mask for photolithography, includes a cover and a base having a plurality of tapered corners. The tapered corners taper outward and downward from a top major surface of the base. The cover having the tapered corners extends downward that covers the tapered corners of the base when the cover is attached to the base. The tapered corners of the cover are tapered at about the same angle as the tapered corners of the base so that a surface of the tapered corners of the cover is substantially parallel to a corresponding surface of the tapered corner of the base when the cover is attached to the base. A recess is located in the tapered corners of the cover. A biasing member and a ball-shaped member are located in the tapered corners of the base to mate with the recess when the cover is attached to the base.