Imprint Apparatus Mold Positioning Cyclic Error
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional imprint techniques face challenges in achieving high accuracy in specifying the position of the mold's mesa portion due to low position reproducibility of measuring devices, cyclic error phase differences, stray light errors, and fluctuating measurement value deceptions.
Innovation Solution
An imprint apparatus is designed with a mold holding unit, substrate holding unit, measurement unit, driving unit, and control unit. The control unit adjusts the mold's position to ensure the measurement unit operates within a distance range insensitive to cyclic errors, allowing for accurate measurement and positioning of the mold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the measuring device is driven in a plane to measure the distance to the mold surface, then the position of the mesa portion can be specified, but the measurement accuracy is degraded due to cyclic error phase difference and low position reproducibility
Solution Approach 1:
The patent changes the measurement parameter from absolute distance to relative distance change amount. By measuring the change in distance rather than the absolute distance, the system eliminates cyclic error phase differences and achieves high measurement accuracy without requiring high position reproducibility. The control unit calculates the distance change amount between consecutive measurements, which naturally compensates for cyclic errors.
Solution Approach 2:
The patent performs preliminary positioning of the measuring device to a predetermined position before actual measurement. This preliminary action ensures that the measuring device starts from a known reference point, allowing subsequent relative distance measurements to be accurate even if absolute position reproducibility is poor. The system establishes a reference measurement first, then uses differential measurements from that reference.
2Measurement precision
If the measuring device operates at a fixed distance from the mold, then cyclic error can be minimized, but the system lacks adaptability to different mold configurations and positions
Solution Approach 1:
The patent makes the measurement system dynamic by allowing the distance between the measuring device and mold to vary during operation. Instead of fixing the distance, the system dynamically adjusts the distance while continuously measuring and calculating relative distance changes. This dynamic approach maintains measurement precision through differential measurement while providing adaptability to different mold positions and configurations.
Solution Approach 2:
The system implements feedback by continuously measuring the distance to the mold surface and using this information to calculate relative distance changes. The control unit receives measurement values, calculates the distance change amount, and uses this feedback to determine the position of the mesa portion. This feedback mechanism maintains precision across varying distances.
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 enables high-accuracy positioning of the mold, leading to improved pattern formation on substrates with reduced positional shifts and errors, thus enhancing the overall precision of the imprint process.
Implementation Method 1
a measurement unit configured to measure a distance to a surface of the mold held by the mold holding unit, thereby obtaining a measurement value
Data Source
AI summary
An imprint apparatus including a measurement unit configured to measure a distance to a surface of a mold held by a mold holding unit, thereby obtaining a measurement value, and a control unit configured to perform measurement processing of measuring the distance by the measurement unit for a plurality of portions of a structure provided on the surface of the mold while driving the measurement unit, wherein the measurement value includes a cyclic error caused by a distance between the measurement unit and the mold, and before performing the measurement processing, the control unit adjusts a position of the mold holding unit in a direction intersecting a reference surface such that the distance falls within a distance range corresponding to a range where the measurement value is insensitive to the cyclic error.