3D ordered nanostructures fabricated by nanosphere lithography using an organometallic etch mask

Area of Science:

• Materials Science and Engineering
• Nanotechnology
• Surface Science

Background:

• Fabricating ordered porous structures on diverse substrates is crucial for applications in filtration, catalysis, and electronics.
• Existing methods often lack versatility or scalability for creating complex 3D nanostructures.

Purpose of the Study:

• To develop a versatile and efficient method for fabricating porous nanostructures on silicon and polymer surfaces.
• To demonstrate the creation of 3D nanostructures using a combination of nanosphere lithography and nanoimprint lithography.

Main Methods:

• Utilized colloidal silica particle arrays (60-500 nm) on silicon or polyethersulfone (PES) substrates.
• Employed poly(ferrocenylmethylphenylsilane) (PFMPS) as an etch-resistant mask, followed by argon ion sputtering and HF etching.
• Applied reactive ion etching for pattern transfer and cellulose acetate as a sacrificial layer for free-standing membranes.
• Integrated nanosphere lithography (NSL) with nanoimprint lithography (NIL) for 3D nanostructure generation.

Main Results:

• Successfully fabricated regular arrays of circular pores on silicon and PES substrates.
• Created free-standing PES membranes with high porosity.
• Generated 3D hemispherical nanostructures on silicon and PMMA using NSL-NIL combination.

Conclusions:

• The demonstrated NSL-based approach offers a versatile route for fabricating micro- and nanoporous structures.
• The integration with NIL provides a pathway to complex 3D nanostructures with tunable properties.
• This method holds potential for advanced applications requiring precisely engineered porous materials.