Dual Liquid Fluid Handling for Immersion Lithography Meniscus Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The throughput of lithographic apparatuses is limited due to the instability of the meniscus of immersion liquid between the fluid handling structure and the substrate, leading to potential leakage and defects on the substrate, which restricts the speed at which the substrate can be moved under the projection system.
Innovation Solution
A fluid handling system that simultaneously provides two separate liquids to the substrate surface, with a gap between them, allowing for the formation of a liquid layer over the irradiated region to prevent droplet formation and enhance stability, thereby increasing the substrate's movement speed without risking leakage or defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the substrate is moved at high speed under the projection system, then the throughput of the lithographic apparatus is improved, but the meniscus of immersion liquid becomes unstable and leaks, causing defects on the substrate
Solution Approach 1:
The patent divides the liquid handling system into two separate devices: a first device that confines liquid to a first space between the device and the substrate, and a second device that provides liquid to a second space between the device and the substrate. This segmentation allows independent control of liquid supply and confinement, enabling stable liquid layer formation even during high-speed substrate movement, thus resolving the contradiction between throughput improvement and meniscus stability.
2Productivity
If the substrate is moved at high speed, then the throughput is increased, but liquid leakage occurs from the confined area, leading to substrate defects
Solution Approach 1:
The patent introduces a second device as an intermediary system that provides liquid to a second space between the substrate and the second device. This second liquid layer acts as a mediator that prevents liquid leakage from the first confined space, allowing high-speed substrate movement without causing defects. The intermediary liquid layer absorbs the harmful effects of high-speed movement on the primary liquid confinement.
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 approach allows for faster substrate movement while maintaining stability of the liquid layer, reducing the occurrence of watermark defects and increasing the yield of patterned substrates by preventing droplet-related issues.
Implementation Method 1
A fluid handling system for wetting a region of a surface of a substrate irradiated by a radiation beam
Data Source
AI summary
A fluid handling system for wetting a substrate irradiated by radiation. The fluid handling system include a first device to confine a first liquid to a first space between the first device and the substrate. The first device includes a first liquid supply member to provide the first liquid to the first space and an extraction member to remove liquid. The fluid handling system further includes a second device including a second liquid supply member to provide a second liquid to a second space between the second device and the substrate, wherein there is a gap on the surface of the substrate between the first and second liquids. The fluid handling system is configured to provide the second liquid to the second space without removing any liquid from the second space to form a liquid layer, and is configured to provide the first and second liquids on the substrate simultaneously.