Nanopattern transfer from high-density self-assembled nanosphere arrays on prepatterned substrates

Area of Science:

• Materials Science
• Nanotechnology
• Surface Engineering

Background:

• Fabricating high-density, well-defined nanopatterns is crucial for advanced microelectronics and photonics.
• Existing methods for creating nanopatterns often face challenges in scalability and precision.

Purpose of the Study:

• To develop a novel method for fabricating nanoimprint molds with high-density nanopatterns.
• To improve the aspect ratio of nanodots for enhanced mold performance.
• To demonstrate the reproducible transfer of nanopatterns into polymer surfaces.

Main Methods:

• Utilized self-assembled silica nanosphere arrays (100 and 25 nm diameters) on prepatterned substrates.
• Employed capillary force via dip-coating for regular nanosphere arrangement.
• Applied reactive ion etching (RIE) with CF4 and O2 gases using nanosphere arrays as etching masks.
• Incorporated Ruthenium (Ru) and Silicon oxide (SiO(x)) mask layers for optimized pattern transfer.

Main Results:

• Achieved high-density, well-defined nanodot arrays on silica substrates.
• Improved the aspect ratio of nanodots (height to diameter) to approximately two using 25 nm nanospheres.
• Successfully demonstrated inverse pattern transfer into polymer surfaces using UV nanoimprint process.

Conclusions:

• Self-assembled nanosphere arrays provide a scalable route to high-density nanopattern fabrication.
• The combined RIE and mask layer process enhances nanodot aspect ratio and definition.
• The developed nanoimprint molds are suitable for reproducible nanopattern replication in polymers.