Exposure Optics Gas Segmentation for Outgas-Free Substrate Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The generation of outgas from photoresist on a substrate in an exposing apparatus leads to clouding on optical elements, deteriorating exposure and measurement accuracy due to impurities and refractive index fluctuations, which conventional methods struggle to address effectively.
Innovation Solution
An exposing apparatus with a first gas supplying mechanism that supplies clean gas to the space between the substrate and the projecting optical system, setting its direction to avoid optical paths and ensure uniformity with air-conditioning gas, thereby suppressing clouding and refractive index fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If clean gas is supplied to blow off outgas from the substrate, then optical performance deteriorates less, but measurement accuracy deteriorates due to refractive index fluctuations
Solution Approach 1:
The patent divides the space between the substrate and optical element into two distinct regions: a first space for supplying clean gas to blow off outgas, and a second space for allowing measurement light to pass through. This spatial segmentation prevents the clean gas from interfering with the measurement light path, thus maintaining both optical performance and measurement accuracy simultaneously.
2Object-affected harmful factors
If clean gas is supplied at high flow rate to suppress outgas, then clouding on optical element is reduced, but measurement accuracy deteriorates due to gas entrainment
Solution Approach 1:
The patent segments the gas supply region from the measurement light path region. By providing a dedicated first space for high-flow clean gas supply and a separate second space for measurement light passage, the system can maintain high gas flow rates to prevent clouding without causing refractive index fluctuations in the measurement path.
3Device complexity
If the space between substrate and optical element is used for both gas supply and measurement, then device complexity is reduced, but exposure performance deteriorates
Solution Approach 1:
The patent introduces a spatial segmentation within the existing space, creating functionally distinct first and second spaces. This approach maintains relative structural simplicity while achieving the dual functionality of outgas suppression and accurate measurement, thereby preserving exposure performance without significantly increasing device complexity.
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 effectively prevents clouding on optical elements and maintains exposure and measurement accuracy by using clean gas to suppress outgas, ensuring high-quality manufacturing processes.
Implementation Method 1
a first gas supplying mechanism configured to supply first gas toward a first space between the projecting optical system and the substrate
Implementation Method 2
a measuring unit configured to measure a position of the substrate in a first direction perpendicular to a substrate surface of the substrate by making measurement light incident on the substrate surface and to receive the measurement light reflected by the substrate surface
Data Source
AI summary
An exposing apparatus for exposing a substrate to transfer a pattern formed on an original to the substrate by using exposure light from a light source includes a projecting optical system configured to guide the exposure light having passed through the original to the substrate, a measuring unit configured to measure a position of the substrate in a first direction perpendicular to a substrate surface of the substrate by making measurement light incident on the substrate surface and to receive the measurement light reflected by the substrate surface, and a traveling direction setting means configured to set a traveling direction of first gas so as to supply the first gas toward a first space between the projecting optical system and the substrate from a first gas supplying mechanism, in which the first space is different from a second space through which the measurement light passes.