High Contrast Alignment Marks in Imprint Templates
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Solution Overview
Problem
Current nano-fabrication techniques face challenges in aligning templates and substrates due to the need for large open spaces and trenches for high contrast alignment marks, which can be detrimental to processes like chemical-mechanical planarization and etching, and result in pattern placement errors.
Innovation Solution
The use of high contrast materials with different refractive indices for alignment marks, deposited within recesses of the alignment area, allowing for precise alignment without the need for trenches, and enabling the same step patterning of alignment marks and primary features, with a hard mask and selective etching processes to maintain feature integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If large open spaces and trenches are created for high contrast alignment marks, then alignment visibility is improved, but device complexity and process difficulty increase
Solution Approach 1:
The alignment marks are formed with local high contrast material deposition only in specific regions (alignment areas) rather than requiring large open spaces or trenches across the entire substrate. This localized approach provides sufficient visibility for alignment while avoiding the complexity of extensive trench structures.
Solution Approach 2:
Instead of creating visibility through lateral dimensions (large open spaces or deep trenches), the solution uses vertical dimension by depositing high contrast material layers of specific thicknesses. The alignment marks achieve visibility through material composition and layer thickness rather than through large spatial dimensions.
2Measurement precision
If trenches are created for alignment marks, then alignment contrast is improved, but etching uniformity deteriorates
Solution Approach 1:
High contrast material is deposited locally in alignment areas rather than requiring trench structures. This localized deposition maintains flat substrate surfaces and avoids the etching non-uniformities that would result from trench formation, while still providing sufficient alignment contrast.
3Measurement precision
If alignment marks are made visible through material removal, then alignment visibility is improved, but residual layer thickness increases
Solution Approach 1:
The alignment marks utilize composite material structures with high contrast materials deposited in specific layers. By strategically depositing high contrast materials in certain layers and removing them selectively from alignment areas, the solution achieves visibility without requiring thick residual layers, maintaining precision while enabling effective alignment.
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 approach reduces the scribe width, enhances integration with existing semiconductor processes, improves etching uniformity, and minimizes defects by allowing alignment marks to be visible within the formable material, thus facilitating precise pattern transfer with reduced residual layer thickness.
Implementation Method 1
The formable liquid is solidified to form a rigid layer that has a pattern conforming to a shape of the surface of the template that contacts the formable liquid
Implementation Method 2
The use of high contrast materials with different refractive indices for alignment marks, deposited within recesses of the alignment area
Data Source
AI summary
Described are systems and methods for formation of templates having alignment marks with high contrast material. High contrast material may be positioned within recesses of alignment marks.