Digital Lithography Imaging Layout to Mitigate Moire Alignment Errors
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Solution Overview
Problem
The Moire effect in digital lithography systems causes alignment difficulties due to the overlay of grids or patterns with slight angular or size differences, leading to unreliable substrate alignment and patterning errors.
Innovation Solution
A digital lithography system with unequal optical path lengths for the digital micro-mirror device (DMD) and imaging device, mitigating the Moire effect by adjusting the optical path length of the imaging device to eliminate interference patterns, ensuring precise and accurate substrate alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the optical path lengths of the DMD and imaging device are made equal, then the imaging system can achieve proper focus and image capture, but the Moire effect occurs causing alignment errors and reduced measurement precision
Solution Approach 1:
The patent changes the optical path length parameter of the imaging device to be unequal to that of the DMD. This parameter modification eliminates the Moire effect by preventing the overlay of identical periodic patterns, thereby resolving the contradiction between achieving proper focus and avoiding alignment errors caused by the Moire effect.
2Reliability
If the imaging device is positioned with equal optical path length to the DMD, then the system maintains simple optical configuration, but alignment reliability deteriorates due to Moire effect interference patterns
Solution Approach 1:
The patent modifies the optical path length parameter of the imaging device, making it unequal to the DMD's optical path length. This simple parameter change eliminates the Moire effect and improves substrate alignment reliability without requiring complex additional optical components or configurations.
3Manufacturing precision
If equal optical path lengths are used for DMD and imaging device, then the optical system remains simple and compact, but patterning accuracy decreases due to Moire effect causing misalignment
Solution Approach 1:
The patent applies a parameter change to the optical path length of the imaging device, setting it unequal to the DMD's optical path length. This modification eliminates the Moire effect that causes patterning misalignment, thereby improving manufacturing precision while maintaining optical system simplicity through a straightforward parameter adjustment.
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 system achieves improved image quality and alignment precision, reducing patterning errors and increasing throughput by eliminating the Moire effect, allowing more patterns to be accurately placed on substrates without misalignment.
Implementation Method 1
a digital micro-mirror device (DMD) configured to receive the light beam and form an output light beam
Implementation Method 2
an imaging device configured to capture an image of the substrate illuminated at least in part by the output light beam
Data Source
AI summary
A digital lithography system includes a light source configured to emit a light beam along an optical path toward a substrate via one or more optical elements. The digital lithography system further includes a digital micro-mirror device (DMD) configured to receive the light beam and form an output light beam. The output light beam is emitted along the optical path toward the substrate. The digital lithography system further includes an imaging device configured to capture an image of the substrate illuminated at least in part by the output light beam. A first optical path length corresponding to the DMD and a second optical path length corresponding to the imaging device are unequal.