Gap-directed chemical lift-off lithographic nanoarchitectonics for arbitrary sub-micrometer patterning

Area of Science:

• Materials Science
• Nanotechnology
• Surface Chemistry

Background:

• Self-assembled monolayers (SAMs) are crucial for surface patterning.
• Traditional lithography faces limitations in achieving ultra-small feature sizes.
• Soft lithography offers flexibility but often lacks high resolution.

Purpose of the Study:

• To introduce a novel soft lithography method for creating sub-10 nm surface patterns.
• To demonstrate the use of stamp roof collapse-induced gaps for selective material removal.
• To explore the potential of these patterns for biorecognition and nanostructure fabrication.

Main Methods:

• Utilized a unique soft lithographic operation involving stamp roof collapse.
• Employed chemical lift-off lithography (CLL) to selectively remove alkanethiol SAMs on gold (Au).
• Investigated the effect of stamp structure dimensions (height, pitch, shape) on pattern size.

Main Results:

• Achieved surface patterns orders of magnitude smaller than the original stamp features.
• Demonstrated the smallest feature dimension of 5 nm using a micrometer-scale structured stamp.
• Observed that molecular pattern sizes in gaps follow mathematical predictions and are tunable.

Conclusions:

• Soft material properties can be leveraged for high-resolution patterning.
• The developed CLL process combined with the gap phenomenon enables straightforward sub-10 nm feature creation.
• Generated molecular patterns are suitable for biorecognition arrays and metallic structure fabrication.