Multi-step proportional miniaturization to sub-micron dimensions using pre-stressed polymer films

Area of Science:

• Materials Science and Engineering
• Nanotechnology
• Microfabrication

Background:

• Scalable nanoscale pattern fabrication is essential for integrated circuits, nanofluidics, and micro/nanoelectromechanical systems.
• Traditional top-down nanofabrication relies on master fabrication, which is often time-consuming and costly.
• Existing methods for pattern shrinking on pre-stressed films lack iterative capability for nanoscale resolution.

Purpose of the Study:

• To demonstrate a scalable fabrication process for iterative nanoscale pattern miniaturization.
• To achieve pattern resolution in the order of hundreds of nanometers through multiple shrinking cycles.
• To validate the application of the fabricated patterns in semiconductor microfabrication and microsystems.

Main Methods:

• A pattern transfer method combining soft imprint lithography and reactive ion etching to pattern a shrinkable polymer film.
• Thermal shrinking of the patterned polymer film to reduce feature size in iterative cycles.
• Utilizing the shrunk pattern as a master for subsequent cycles of pattern transfer and shrinking.

Main Results:

• Demonstrated iterative shrinking over three cycles, achieving a 60% size reduction per cycle.
• Generated sub-micron patterns (750 nm) with an approximate 20x overall size reduction from original patterns.
• Successfully transferred nanoscale patterns into a silicon substrate, showcasing potential for microfabrication.

Conclusions:

• The developed multi-step miniaturization process enables accurate nanoscale pattern fabrication through iterative shrinking.
• This scalable approach offers a cost-effective alternative to traditional master fabrication for micro/nanosystems.
• The technique is applicable for creating masters for semiconductor microfabrication and advanced microsystems.