Exposure Apparatus Stage Purge Gas Segmentation
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Solution Overview
Problem
Existing exposure apparatuses for semiconductor devices and liquid crystal panels face issues with fogging of the original due to acid, base, or organic impurities in the atmosphere, which leads to insufficient exposure and increased purge gas usage to prevent external air intrusion.
Innovation Solution
The exposure apparatus incorporates a design with a first concave portion for the original and second concave portions on either side, which are filled with a purge gas to maintain high air pressure and reduce external air flow, thereby minimizing the amount of purge gas required.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the entire movable region of the original stage is covered with a plate to form a large internal space, then the original is protected from external air intrusion, but a large amount of purge gas needs to be continuously supplied to fill the large volume
Solution Approach 1:
The internal space is divided into multiple regions: a first space directly above the original and second spaces at the lateral ends. Each region is independently supplied with purge gas through separate supply units positioned at different locations, allowing localized protection rather than filling the entire large volume uniformly.
Solution Approach 2:
Purge gas is supplied preferentially to the first space above the original where the original is most vulnerable to fogging, and to the second spaces at the lateral ends where external air intrusion occurs. This localized supply strategy protects critical areas while minimizing overall purge gas consumption compared to filling the entire large internal space.
2Reliability
If purge gas is supplied to prevent external air intrusion, then the original is protected from fogging, but the running cost increases due to continuous purge gas consumption
Solution Approach 1:
The purge gas supply system is segmented into multiple independent supply units positioned at different locations (above the original and at lateral ends). This allows selective supply to only those regions where external air intrusion is most likely to occur, reducing overall purge gas consumption while maintaining pattern transfer accuracy.
Solution Approach 2:
Purge gas is supplied locally to specific high-risk areas (first space above original, second spaces at lateral ends) rather than uniformly to the entire internal space. This targeted approach maintains reliability by protecting the original from fogging at critical locations while minimizing purge gas waste.
3Object-affected harmful factors
If a large internal space is formed to cover the movable region, then complete protection from external air is achieved, but the volume of purge gas required increases significantly
Solution Approach 1:
The internal space is segmented into a first space directly above the original and second spaces at the lateral ends. Purge gas supply units are positioned to target these specific segmented regions, allowing effective fogging prevention in the critical first space while using the second spaces to block external air intrusion paths without requiring filling of the entire large volume.
Solution Approach 2:
The purge gas supply is concentrated in the first space above the original where fogging occurs, and at the lateral ends where external air intrusion happens. This local quality approach achieves complete protection against fogging and external air intrusion while minimizing the total volume of purge gas required, avoiding the need to fill the entire large internal space uniformly.
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3C
AI summary
An exposure apparatus exposes a substrate (W) while scanning an original (M) and the substrate, and includes: a stage (2) that includes a first surface (20) in which a first concave portion (20a) and a second concave portion (20b) to be supplied with a purge gas are formed, and is movable while holding the original; and a member (7) including a second surface (70) facing the first surface, wherein the first concave portion is provided in the first surface of the stage so as to define a first space in which the original is arranged, and at least one second concave portion is provided outside the first concave portion in the first surface of the stage so as to define a second space having a smaller volume than the first space.