Exposure Apparatus Gas Flow Rectification for Optical Fogging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing exposure apparatuses face challenges in preventing fogging of optical elements due to contaminants, as current purge gas mechanisms either fail to effectively separate contaminants from the projection optical system or increase the risk of contamination by adjusting flow rates, leading to reduced optical performance.
Innovation Solution
An exposure apparatus with a supply unit that crosses the optical axis, creating a flow rate distribution by dividing the gas flow path into two paths, where the flow rate is higher at a position farther from the projection optical system, reducing contaminants reaching the optical element and increasing the flow rate on the substrate side to direct resist gases away from the optical element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the flow rate of purge gas is lowered to reduce contaminants reaching the optical element, then fogging of the optical element is reduced, but the ability to guide contaminants away from the projection optical system is weakened
Solution Approach 1:
The patent applies local quality by creating different flow rate conditions at different locations: low flow rate near the optical element to prevent contamin deposition, and high flow rate near the substrate to effectively guide contaminants away. This spatial variation in flow characteristics resolves the contradiction between preventing fogging and maintaining contaminant removal effectiveness.
Solution Approach 2:
The patent employs dynamics by creating a non-uniform flow rate distribution that varies along the gas flow path. The flow rate is dynamically adjusted through the flow path design, being lower near the optical element and higher near the substrate, allowing the system to adapt to different requirements at different positions simultaneously.
2Reliability
If the flow rate of purge gas is increased to guide contaminants away from the projection optical system, then contaminant removal effectiveness is improved, but the amount of contaminants reaching the optical element increases
Solution Approach 1:
The patent applies local quality by creating different flow rate conditions at different locations: low flow rate near the optical element to prevent contamin deposition, and high flow rate near the substrate to effectively guide contaminants away. This spatial variation in flow characteristics resolves the contradiction between preventing fogging and maintaining contaminant removal effectiveness.
Solution Approach 2:
The patent employs dynamics by creating a non-uniform flow rate distribution that varies along the gas flow path. The flow rate is dynamically adjusted through the flow path design, being lower near the optical element and higher near the substrate, allowing the system to adapt to different requirements at different positions simultaneously.
3Object-generated harmful factors
If a gas supply mechanism is provided to supply purge gas between the optical element and substrate, then resist gas generated from substrate is guided away from optical element, but contaminants in purge gas adhere to optical element surface
Solution Approach 1:
The patent applies local quality by creating different flow rate conditions at different locations: low flow rate near the optical element to prevent contamin deposition, and high flow rate near the substrate to effectively guide contaminants away. This spatial variation in flow characteristics resolves the contradiction between preventing fogging and maintaining contaminant removal effectiveness.
Solution Approach 2:
The patent converts the harmful effect of purge gas contaminants into a beneficial arrangement by designing the flow path to utilize the gas flow direction. The gas flow that would normally carry contaminants to the optical element is instead directed to flow along the substrate surface and away from the optical element, transforming a potential harm into a protective mechanism.
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
This solution effectively reduces fogging of the optical elements by minimizing contaminants reaching the optical element while increasing the flow rate on the substrate side, thereby enhancing the optical performance and reducing contamination risks.
Implementation Method 1
a supply unit configured to supply a gas so as to cross the optical axis of the projection optical system, in a space between the projection optical system and the substrate facing each other
Data Source
AI summary
An exposure apparatus that exposes a substrate W has a rectifying mechanism 3 that supplies a gas so as to traverse the optical axis of a projection optical system 1, in a space between the projection optical system 1 and the substrate W that face each other, the flow rectifying mechanism 3 supplies a gas so as to have a flow rate distribution in which a flow rate at a second position that is located farther from the projection optical system 1 than a first position is higher than a flow rate at the first position, and the rectifying mechanism 3 includes a first rectifying mechanism 302 that forms a flow rate distribution by dividing a flow path of the gas into a first flow path of a gas flowing to a first position and a second flow path of a gas flowing to a second position.