Controlled Patterning of Vertical Silicon Structures Using Polymer Lithography and Wet Chemical Etching

Area of Science:

• Materials Science
• Nanotechnology
• Surface Science

Background:

• Silicon nanostructures are crucial for advanced electronic and photonic applications.
• Existing fabrication methods often lack scalability, cost-effectiveness, or precise control.
• Developing wafer-scale fabrication techniques for patterned silicon is essential for industrial adoption.

Purpose of the Study:

• To develop a facile and scalable method for fabricating micro/nano-patterned vertical silicon structures.
• To demonstrate the versatility of the method for producing porous silicon, silicon nanowires, and silicon nanorods.
• To investigate the influence of process parameters on the characteristics of fabricated silicon nanostructures.

Main Methods:

• Combination of lithography techniques (photolithography, thermal nano-imprint, nanosphere lithography).
• Utilized wet chemical etching processes (electro-chemical etching, metal-assisted chemical etching).
• Varied metal layer thickness and etching time to control nanostructure dimensions.

Main Results:

• Successfully fabricated micro-patterned porous silicon with controllable pore diameters (30 nm to 1.2 µm).
• Produced micro/nano-patterned silicon microstructures, nanorods, and nanowires by adjusting metal layer thickness.
• Demonstrated control over etched silicon nanowire length through etching time and patterning.

Conclusions:

• The developed method offers a simple, fast, and low-cost approach for large-scale production of patterned silicon nanostructures.
• The technique allows for easy manipulation of size and shape, meeting diverse application requirements.
• This fabrication strategy is promising for advancing silicon-based micro/nano-device manufacturing.