Imprint Lithography Template Alignment Mark Segmentation
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Solution Overview
Problem
In imprint lithography, the alignment of the imprint template with the substrate is challenging due to the filling of alignment marks with imprintable medium, leading to severe contrast loss and poor signal-to-noise ratio, and the use of opaque materials to improve contrast can result in substrate damage.
Innovation Solution
The alignment marks are configured to prevent filling by imprintable medium through specific aspect ratios, depths, widths, or profiles, and are recessed relative to the patterned region, allowing for improved contrast and reduced risk of substrate contact with opaque materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If alignment marks are provided on the imprint template, then alignment between the imprint template and substrate can be performed, but the alignment marks become filled with imprintable medium during imprinting, causing severe contrast loss and poor signal-to-noise ratio
Solution Approach 1:
The alignment mark is segmented into two distinct parts: a first part that remains unfilled by imprintable medium (maintaining contrast for alignment) and a second part that is filled with imprintable medium (enabling pattern transfer). This segmentation allows the alignment mark to serve dual functions without compromising alignment accuracy.
Solution Approach 2:
Different regions of the alignment mark are assigned different properties: the first part has properties that prevent filling (maintaining refractive index contrast), while the second part has properties that allow filling (enabling pattern replication). This local differentiation resolves the contradiction between maintaining contrast and enabling imprinting.
2Measurement precision
If opaque material is applied to alignment marks to improve contrast, then alignment signal-to-noise ratio improves, but the opaque material may contact the substrate and cause damage
Solution Approach 1:
The first part of the alignment mark acts as an intermediary structure that provides the necessary contrast for alignment without requiring opaque materials that could damage the substrate. The unfilled first part maintains refractive index contrast with the imprintable medium, eliminating the need for potentially harmful opaque coatings.
3Measurement precision
If recesses are provided to prevent imprintable medium from reaching alignment marks, then alignment contrast is maintained, but the area available for patterning is reduced
Solution Approach 1:
The alignment mark is divided into unfilled and filled parts, eliminating the need for surrounding recesses. This segmentation allows the entire substrate area to be used for patterning while maintaining alignment contrast through the unfilled first part of the alignment mark.
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 configuration enhances the accuracy of alignment by maintaining a clear path for radiation, reducing substrate damage, and allowing for more efficient use of substrate space without the need for additional recesses, thus improving the overall alignment process and template design.
Implementation Method 1
The alignment mark is configured such that imprintable medium is prevented from filling the alignment mark when the imprint template imprints the imprintable medium
Implementation Method 2
The refractive index of imprintable medium may correspond substantially with a refractive index of the imprint template
Implementation Method 3
Diffraction of the radiation and/or the movement of fringes may be used in the alignment process
Data Source
AI summary
An imprint lithography template is disclosed. In an embodiment, the template includes a patterned region to imprint a layer of imprintable medium, and an alignment mark for use in aligning the imprint template, the alignment mark configured such that imprintable medium is prevented from filling the alignment mark when the imprint template imprints the imprintable medium.