Lithographic patterning of conformal thin films on 3D structures using Scaffold-architected Lift-off masks

Area of Science:

• Materials Science
• Nanotechnology
• Surface Engineering

Background:

• Micro- and nanoscale patterning of thin films on 3D structures is crucial for soft robotics, photonics, and MEMS.
• Current methods face challenges in achieving high resolution, thickness control, and surface conformity on complex geometries.

Purpose of the Study:

• To develop a robust approach for high-resolution, conformal thin-film patterning on complex 3D structures.
• To overcome limitations of existing patterning techniques for micro- and nanoscale applications.

Main Methods:

• Utilized a lithographically defined 3D Scaffold-Architected Lift-Off (SALO) mask within a lift-off process.
• Demonstrated patterning on sloped surfaces (up to 90°) with dimensions ranging from 100 μm down to sub-30 nm.
• Showcased compatibility with various thin-film deposition processes, including atomic layer deposition (ALD).

Main Results:

• Achieved multiscale patterning (100 μm to 100 nm, down to sub-30 nm) on complex 3D surfaces.
• Enabled conformal thin-film coating patterning, including challenging ALD coatings, with high fidelity.
• Demonstrated successful lift-off patterning on sloped surfaces, overcoming limitations of shadowing techniques.

Conclusions:

• The SALO approach provides a versatile and effective solution for micro- and nanoscale patterning on arbitrary 3D structures.
• This method enhances manufacturing capabilities for advanced 3D devices in fields like soft robotics and photonics.
• Opens new avenues for creating intricate micro- and nanoscale features on complex external surfaces.