Pattern Drawing Device Alignment on Flexible Substrates
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Solution Overview
Problem
Conventional pattern drawing apparatuses face challenges in achieving high alignment and overlay accuracy on flexible substrates due to deformation caused by expansion and contraction, especially when the pattern area is large and the feature sizes are fine, making it difficult to estimate deformation accurately within the exposure unit region.
Innovation Solution
A pattern drawing apparatus that projects a beam from a light source onto a substrate, scans in the main scanning direction with intensity modulation, and includes a deflecting member and a reflected light detecting section to measure the relative positional relationship between patterns, ensuring accurate alignment and overlay by photoelectrically detecting reflected light and adjusting the beam intensity accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If marks are detected only around the exposure unit region to measure substrate deformation, then the measurement system is simple, but the alignment accuracy and overlay accuracy are locally worsened within the exposure unit region when the pattern area is large and feature sizes are fine
Solution Approach 1:
The patent divides the measurement approach into two segments: (1) detection of marks around the exposure unit region to measure overall substrate deformation, and (2) detection of marks within the exposure unit region to measure local deformation. This segmentation allows comprehensive deformation measurement without excessive complexity by focusing detailed measurement only where needed for high precision patterns.
Solution Approach 2:
The patent applies different measurement qualities to different regions: overall deformation is measured using marks around the exposure unit, while local deformation is measured using marks within the exposure unit region. This local quality approach ensures high alignment accuracy where fine features require it, while maintaining overall system efficiency.
2Productivity
If the exposure unit region has a large surface area, then the productivity is improved, but it becomes difficult to estimate the state of deformation occurring inside the exposure unit region with high accuracy
Solution Approach 1:
The patent segments the deformation measurement into hierarchical levels: global deformation measured by marks around the exposure unit, and local deformation measured by marks within the exposure unit. This allows large exposure areas to be processed while maintaining accurate deformation estimation through localized measurement data.
Solution Approach 2:
The patent uses feedback from mark position detections to continuously update the deformation state estimation. By detecting mark positions both inside and around the exposure unit, the system receives feedback about substrate deformation and adjusts the pattern drawing accordingly to maintain measurement precision across large areas.
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 enhances alignment and overlay accuracy by accurately measuring and adjusting for substrate deformation, improving the precision of pattern drawing on flexible substrates with varying dimensions and feature sizes.
Implementation Method 1
a reflected light detecting section that photoelectrically detects, via the deflecting member of the beam scanning section, reflected light emitted when the beam is projected onto the substrate
Data Source
AI summary
An exposure device that draws a pattern on a substrate by shining a beam from a light source device on substrate and scanning the beam in a main scanning direction while varying the intensity of beam according to pattern information, including: a scanning unit having a beam scanning unit that includes a polygonal mirror whereby the beam is oriented to scan the beam, and light detector for photoelectric detection of reflected light generated when beam is shined on substrate; an electro-optical element for controlling the beam's intensity modulation according to pattern information such that at least part of second pattern to be newly drawn is drawn on top of at least part of first pattern formed on substrate; and a measurement unit measuring relative positional relationship between the first and second pattern on the basis of a detection signal output by the detector while second pattern is drawn on substrate.