Zentrales Innovationsprogramm Mittelstand (ZIM) des BMWK: Inkjet-basierte Nanoimprint-Lithographie für den Mikro- und Nanostrukturtransfer in hochbrechenden Materialien (InkNIL)

The "InkNIL" project aims to develop solvent-based inkjet inks for structure transfer using plasma etching onto high-refractive materials and substrates. Key requirements for the inks include high etching selectivity, compatibility with standard industrial print heads, and droplet stability, all influenced by the liquid's viscosity and surface tension. A closed layer with a thickness of no more than 200 nm (ideally 100 nm) is crucial for nanoimprint applications. The inkjet process allows for spatially selective application, enabling the creation of varying material heights through advanced overprinting techniques.

Selective application is vital for imprinting with varying stamp fill factors. Adjusting the resist volume to match the stamp structure density can lead to more uniform and thinner residual layers after imprinting, aiming for a resolution below 100 nm and a residual layer thickness of less than 10% of the structure height.

ZfM is exploring reactive ion etching processes for materials like TiO₂, focusing on the resistance of the resist system to fluorine- and chlorine-based chemistries on SiO₂ and Si (e.g.). The project seeks etching results that match or exceed those of established systems. Additionally, new cleaning and conditioning processes will be developed to address non-volatile residues on reactor walls and to effectively remove post-etch residues.

This project is supported by the Federal Ministry for Economic Affairs and Climate Action (BMWK) on the basis of a decision by the German Bundestag.