Reflection Member in Substrate Holding Gap for Exposure Uniformity
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Solution Overview
Problem
In photolithographic device manufacturing, exposure non-uniformity occurs due to reflected light from the base and substrate lifting mechanism, causing variations in light exposure on the substrate, particularly in regions above gaps between these components, leading to inconsistent pattern formation.
Innovation Solution
A substrate holding apparatus with a base and a reflection member in the gap, where the reflection member has a higher reflectance than the base, is used to redirect exposure light back onto the substrate, minimizing flare light and reducing exposure non-uniformity by optimizing the reflectance and shape factors of the reflection surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a base and substrate lifting mechanism are provided below the substrate, then the substrate can be held and delivered, but exposure non-uniformity occurs due to reflected light from the base and lifting mechanism
Solution Approach 1:
The invention converts the harmful reflected light from the base and substrate lifting mechanism into beneficial light by using a reflection member to redirect the reflected light back onto the substrate. This transforms the exposure non-uniformity problem caused by reflected light into a solution where the reflected light is utilized to improve exposure uniformity across the substrate surface.
Solution Approach 2:
The invention introduces a reflection member as an intermediary component between the base/substrate lifting mechanism and the substrate. This reflection member mediates the interaction by capturing reflected light from the base and lifting mechanism and redirecting it onto the substrate, thereby solving the exposure non-uniformity problem while maintaining the substrate holding and delivery function.
2Manufacturing precision
If an antireflection member is provided in the gap to reduce exposure non-uniformity, then reflected light is limited, but the structure becomes more complex
Solution Approach 1:
The invention makes the base or substrate lifting mechanism serve multiple functions: it not only holds and delivers the substrate but also acts as a light reflection surface through the added reflection member. This multi-functional approach eliminates the need for separate antireflection members while maintaining exposure uniformity, thereby reducing structural complexity.
Solution Approach 2:
The invention changes the optical parameters (reflectance characteristics) of the base or substrate lifting mechanism by adding a reflection member with specific reflectance properties. This parameter change allows the existing structure to control reflected light effectively without requiring additional complex antireflection components.
3Manufacturing precision
If the reflectance of the reflection member is increased to improve light distribution, then exposure uniformity improves, but more light is reflected back which may cause over-exposure in certain regions
Solution Approach 1:
The invention applies local quality by positioning the reflection member specifically in the gap region below the substrate and designing it with localized reflectance characteristics. This ensures that reflected light is redirected primarily to areas needing exposure uniformity while avoiding excessive light intensity in regions that already receive sufficient light, thus preventing over-exposure.
Solution Approach 2:
The invention implements a feedback mechanism where the reflection member redirects reflected light back onto the substrate based on the actual light distribution pattern. This creates a self-regulating system where light that would otherwise be lost or cause non-uniformity is fed back into the exposure process in a controlled manner, improving uniformity without causing over-exposure.
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 significantly reduces exposure non-uniformity by ensuring consistent light distribution across the substrate, improving pattern accuracy and precision in device manufacturing.
Implementation Method 1
a reflection member disposed in the gap and configured to reflect light transmitting through the substrate towards the substrate
Data Source
AI summary
There is provided a substrate holding apparatus including a base provided with a gap and a reflection member disposed in the gap and configured to reflect light that has transmitted the substrate to the substrate side, and an exposure apparatus including the substrate holding apparatus.