Imprint Lithography Alignment Using Composite Grating Reflection
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Solution Overview
Problem
In lithography, achieving precise alignment between patterns on a substrate and an imprint template is crucial for functional device production, but existing methods are costly and limited by radiation wavelength or numerical aperture, and there is a need for a more cost-effective and accurate alignment technique.
Innovation Solution
A method and apparatus using a lithographic apparatus with an imprint template holder, substrate table, alignment radiation beam source, and detector to determine the position of a substrate relative to an imprint template by detecting the intensity of radiation reflected from composite gratings, allowing for precise alignment without the limitations of radiation wavelength or numerical aperture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If photolithography is used to achieve smaller features, then feature size is reduced, but cost increases due to expensive equipment and materials
Solution Approach 1:
The patent replaces optical photolithography systems with mechanical imprint lithography. Instead of using expensive optical equipment (immersion lithography, EUV radiation lithography), the invention uses a physical stamp or imprint template to directly transfer patterns onto the substrate. This mechanical approach eliminates the need for costly optical systems while achieving the same pattern transfer function.
Solution Approach 2:
The invention changes the fundamental parameter from optical wavelength-limited resolution to mechanical contact resolution. By using direct physical contact between the imprint template and substrate, the resolution is no longer constrained by optical parameters such as wavelength or numerical aperture, enabling smaller features at lower cost.
2Ease of manufacture
If imprint lithography is used to reduce cost, then manufacturing cost decreases, but alignment precision between layers may worsen
Solution Approach 1:
The patent incorporates alignment marks and detection systems that provide feedback on the relative position between the imprint template and substrate. By detecting the position of alignment marks and calculating displacement, the system can adjust and correct alignment errors, ensuring precise registration between layers despite the mechanical nature of the process.
Solution Approach 2:
The invention introduces alignment marks as intermediary elements between the imprint template and substrate. These marks serve as reference points that enable precise measurement and adjustment of relative positions, facilitating accurate alignment without requiring complex direct measurement systems.
3Manufacturing precision
If alignment apparatus is added to ensure precise alignment, then alignment precision improves, but device complexity increases
Solution Approach 1:
The patent enables the imprint lithography system to perform its own alignment through integrated alignment marks and detection capabilities. The system uses the reflected radiation from composite gratings to automatically determine displacement and adjust positioning, eliminating the need for separate, complex external alignment apparatus.
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
Enables accurate and cost-effective alignment of substrate and imprint template, ensuring proper electrical connections between layers and improving the functionality of devices by using the intensity of reflected radiation from composite gratings to determine displacement and achieve precise positioning.
Implementation Method 1
detecting an intensity of radiation which is reflected by the three composite gratings
Data Source
AI summary
A method of determining a position of a substrate relative to an imprint template is described, wherein the imprint template has at least three gratings and the substrate has at least three gratings positioned such that each imprint template grating forms a composite grating with an associated substrate grating, the at least three imprint template gratings and associated substrate gratings having offsets relative to one another. The method includes detecting an intensity of radiation which is reflected by the three composite gratings, and using the detected intensities to determine displacement of the substrate or imprint template from a position.