Imprint Inspection Using Sub-Pixel Stage Shift Imaging
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Solution Overview
Problem
Existing imprint inspection techniques require extensive time due to narrow visual fields and high computational resources, making them inefficient for inspecting large imprint regions on substrates.
Innovation Solution
An imprint apparatus and method utilizing a stage-driven substrate, a dispenser, and an imaging unit to capture sub-pixel shift images, allowing for rapid inspection by shifting and averaging images to enhance defect detection precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a high magnification microscope is used to inspect the imprint pattern, then measurement precision is improved, but inspection time increases significantly
Solution Approach 1:
The inspection system divides the large-area substrate into multiple shot regions and inspects them in sequence. The imaging unit captures images of different shot regions by moving the substrate stage, allowing comprehensive inspection without requiring a single excessively large sensor that would reduce resolution.
Solution Approach 2:
The system uses sub-pixel shift technology where the substrate stage moves in sub-pixel increments during image capture. By capturing multiple images with sub-pixel displacements and combining them through image processing, the system achieves higher effective resolution without proportionally increasing inspection time.
2Measurement precision
If sub-pixel shift imaging is performed to enhance defect detection, then measurement precision is improved, but computational load and memory requirements increase
Solution Approach 1:
The system extracts and processes only the necessary sub-pixel shift images for inspection purposes. Rather than processing all possible image data, the control unit selectively captures and processes images at specific sub-pixel positions, reducing the overall computational burden while maintaining detection sensitivity.
Solution Approach 2:
The system performs sub-pixel shift imaging with a controlled number of displacement steps that provides sufficient detection accuracy without excessive processing. The sub-pixel shift amount and number of capture positions are optimized to achieve the required measurement precision with minimal computational overhead.
3Productivity
If the visual field of the microscope is increased to reduce inspection time, then productivity is improved, but measurement precision deteriorates
Solution Approach 1:
The imaging unit serves multiple functions: it captures images at normal pixel resolution for general inspection and also captures images at sub-pixel resolution for enhanced defect detection. This multi-functionality allows the system to maintain high productivity while achieving high precision when needed.
Solution Approach 2:
The system dynamically adjusts the imaging mode and stage movement speed based on the inspection requirements. For areas requiring high precision, sub-pixel shift imaging is performed with slower stage movement, while for routine inspection, faster normal-speed imaging is used, optimizing the balance between productivity and precision.
Data Source
AI summary
An imprint apparatus for performing an imprint process of forming a pattern of an imprint material on a substrate using a mold, including a control unit configured to control a process concerning inspection of the imprint process, wherein the imprint process includes an arrangement process including stage driving of driving a stage between a first position below the mold and a second position below a dispenser, and in a case where a plurality of states are obtained, in each of which a shot region is sub-pixel shifted with respect to an imaging surface in accordance with the stage driving during the arrangement process, the control unit obtains a plurality of first sub-pixel shift images corresponding to the plurality of states, and inspects the imprint process based on the plurality of first sub-pixel shift images.