Imprint Alignment Control for Mold-Substrate Shift Prediction
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Solution Overview
Problem
Existing imprint technologies face challenges in reducing the positional shift amount between a mold and a substrate during alignment, which is exacerbated by complex interactions on the substrate surface, leading to prolonged alignment times due to fluctuating shifts.
Innovation Solution
An imprint apparatus with a measurement unit to measure positional shifts and a control unit that estimates and adjusts for these shifts by deforming the mold into a convex shape, allowing for reduced positional errors and faster alignment through data-driven control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If alignment is performed after contact between mold and substrate, then alignment accuracy can be achieved, but alignment time increases significantly due to fluctuating positional shifts
Solution Approach 1:
The patent performs preliminary measurements of positional shift at multiple points during the contact step to predict and compensate for positional drift before alignment is finalized. By measuring at reference time points and calculating predicted positional shifts, the system proactively adjusts for drift rather than reacting to it during alignment, thus maintaining accuracy while reducing alignment time.
Solution Approach 2:
The patent implements a feedback mechanism where positional shift is continuously measured during the contact step, and these measurements are used to update predictions of positional drift. The control unit uses this feedback information to adjust the predicted positional shift at alignment start time, enabling real-time compensation that maintains alignment accuracy while minimizing the time required.
2Reliability
If mold is deformed into convex shape during contact, then bubble prevention is improved, but positional shift fluctuation increases due to complex substrate interactions
Solution Approach 1:
The patent changes the physical parameters of the mold by deforming it into a convex shape during the contact step. This parameter change improves bubble prevention by ensuring better contact between the mold and substrate. The system accepts the resulting positional shift fluctuations as a trade-off, compensating for them through measurement and prediction methods.
Solution Approach 2:
The patent converts the harmful effect of positional shift fluctuation (caused by mold deformation and substrate interactions) into a measurable and predictable parameter. By measuring and predicting the positional drift, the system transforms an unstable condition into controllable information that can be compensated for, thereby maintaining alignment accuracy despite the fluctuations.
3Productivity
If alignment is performed with considerable positional shift at start time, then alignment can be completed, but productivity decreases due to extended alignment duration
Solution Approach 1:
The patent performs preliminary measurements and calculations of predicted positional shift before alignment begins. By having this prediction ready in advance, the system can start alignment with minimal initial positional shift, thereby reducing the time and iterations needed to achieve final alignment precision while maintaining high productivity.
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 solution effectively minimizes positional shifts between the mold and substrate, thereby reducing the time required for alignment and enhancing productivity in imprint processes.
Implementation Method 1
the mold is deformed into a convex shape toward the substrate side so as to prevent bubbles from remaining between the imprint material and the mold
Data Source
AI summary
An imprint apparatus including a control unit configured to obtains data for estimating a fluctuation of a positional shift between a mold and a substrate occurring during a contact step, and when performing an imprint process on the substrate, obtains an estimation value by estimating the positional shift occurring during the contact step from the positional shift measured by a measurement unit at a reference time during the contact step and the data, and drives at least one of the mold and the substrate in the contact step based on the estimation value so as to reduce the positional shift at a start of an alignment step.