Exposure Apparatus Gas Guide Unit for Optical Path Control
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Solution Overview
Problem
In exposure apparatuses used in semiconductor manufacturing, gases generated from photosensitive agents can degrade exposure performance by reducing light transmittance and causing detection errors due to refractive index changes in the optical path, complicating substrate stage control and increasing apparatus complexity and cost.
Innovation Solution
An exposure apparatus with a guide unit that directs gas flows from a blowing unit to specific spaces between the projection optical system and the substrate, and where detection light passes, ensuring distinct gas flows in each area to mitigate gas influence, using a combination of first and second guide portions to manage gas flow along the substrate and within the optical path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate supply/exhaust unit is provided to manage gas generated from the photosensitive agent, then the influence of gas on exposure performance is reduced, but the apparatus arrangement becomes complicated and apparatus cost increases
Solution Approach 1:
The patent combines the gas supply function and gas exhaust function into a single integrated supply/exhaust unit. The unit includes a supply port for introducing inert gas and an exhaust port for discharging generated gas, both integrated into one structural component rather than using separate units. This merging approach reduces apparatus complexity while maintaining the ability to control gas influence on exposure performance
Solution Approach 2:
The supply/exhaust unit serves multiple functions simultaneously: it supplies inert gas to prevent gas generation from affecting exposure, exhausts generated gas from the optical path, and maintains a controlled atmosphere in the chamber. This multi-functionality eliminates the need for separate dedicated units for each function, reducing overall apparatus complexity
2Productivity
If gas is generated from the photosensitive agent during exposure, then the exposure process proceeds normally, but light transmittance decreases and flare is generated in the projection optical system
Solution Approach 1:
The patent applies preliminary anti-action by supplying inert gas (such as nitrogen or carbon dioxide) into the chamber before and during the exposure process. This inert gas creates a protective atmosphere that prevents the photosensitive agent from generating harmful gases that would reduce light transmittance or cause flare in the projection optical system
Solution Approach 2:
The patent creates an inert atmosphere within the exposure chamber by introducing inert gas through the supply port. This inert environment prevents chemical reactions that would generate harmful gases during exposure, thereby maintaining light transmittance and preventing flare while allowing the exposure process to proceed normally
3Productivity
If gas flows into the optical path of the detection unit, then the detection process continues, but refractive index changes cause errors in substrate stage position detection
Solution Approach 1:
The patent uses preliminary anti-action by establishing an inert gas atmosphere in advance that prevents harmful gas generation. The exhaust port continuously removes any generated gases from the optical path area, ensuring that the detection unit operates in a stable atmospheric environment with consistent refractive index, thereby maintaining position detection accuracy
Solution Approach 2:
The inert atmosphere created by the supply/exhaust unit stabilizes the refractive index in the optical path of the detection unit. By maintaining a controlled inert environment and actively exhausting generated gases, the system prevents refractive index fluctuations that would otherwise cause errors in substrate stage position detection
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 configuration effectively reduces the impact of gases on exposure performance and detection accuracy without adding separate gas supply/exhaust units, maintaining cleanliness and reducing apparatus complexity and cost.
Implementation Method 1
a guide unit including a first portion and a second portion, wherein the first portion is configured to guide the gas blown out by the blowing unit, to a first space between the projection optical system and the substrate, such that a gas flow along the substrate is formed in the first space
Implementation Method 2
a detection unit configured to emit detection light in a first direction and detect a position of the stage based on reflected light by the stage
Implementation Method 3
The exposure apparatus can transfer a pattern of a mask to a photosensitive agent (resist) on the substrate by projecting an image of the pattern formed in the mask on the photosensitive agent on the substrate via a projection optical system
Data Source
AI summary
The present invention provides an exposure apparatus exposing a substrate through a projection optical system, the apparatus comprising a stage configured to hold the substrate, a detection unit configured to emit detection light in a first direction and detect a position of the stage, a blowing unit configured to blow out a gas, and a guide unit including a first portion and a second portion, wherein the first portion is configured to guide the gas to a first space between the projection optical system and the substrate, such that a gas flow along the substrate is formed in the first space, and wherein the second portion is configured to guide the gas to a second space where the detection light passes through, such that a gas flow in a second direction is formed in the second space.