TL1 – Sustainable Micro and Nanofabrication
i3N is committed to the UN 2030 SDG, the EU Circular Economy Action Plan and the objectives of the European Chips Act, namely the emergent technologies. As such, research on sustainable micro and nanofabrication strategies is our core activity, seeking for design and process methodologies able to take an economically and environmentally responsible fabrication dimension to the other TLs, always having in mind upscaling capability. Major fields of action are:
- Modelling and simulation
Multiphysics modelling (e.g., COMSOL) provides insights on material and device physical behaviour
and guides novel material growth, functional design, and fabrication. Design of fuel cells, printed
heaters and sensors are being driven by such an approach. Also, Silvaco’s Technology CAD (TCAD)
suite, through its physical-based simulation is enabling the research unit to understand non-idealities in
miniaturised thin-film transistors (TFTs) and deriving design and fabrication strategies to overcome
them. - Green and energy efficient processes
We derive a variety of fabrication processes seeking to minimise hazardous substances and maximise
energy efficiency. A wide range of physical and vapour deposition routes are being used to create thin
films and nanostructures at low temperature, demanding for a solid understanding of the effect of
processing parameters on material properties to control defect density. Materials are also developed
following solution processing routes, replacing toxic solvents like 2-methoxyethanol by environmentally
friendly alternatives, as ethanol or water. Inks can then be deployed by multiple printing technologies
(e.g. ink-jet, flexo), including a recently installed ultra-precise dispensing system enabling sub-μm
linewidths. Photonic-assisted sintering further decreases fabrication temperatures. - Waste reduction and recycling
Additive (e.g., ink-jet printing, 3D-printing, bio-printing) and transformative (e.g., laser-induced
graphene) fabrication routes are crucial at i3N to minimise waste. This goal is also valid for processes
requiring subsequent top-down patterning. A good example is atomic layer deposition (ALD), which is
currently replacing multiple sputtered oxides with improved performance and in some cases 1-fold
thickness reduction. Moreover, we are formulating functional material inks to make nanoimprint
lithography a transformative sub-100 nm technique. i3N is also effectively demonstrating recyclability of
some of its core materials, as nanocellulose derivatives.
Integration strategies
We follow design-for-manufacturability approaches, considering integration from the start. While hybrid
integration is indissociable from the next wave of (opto)electronic systems, many of our developments
can benefit from a simple and cost-effective monolithic integration, given the multifunctionality of our
materials. An example is the use of oxide TFTs both as sensors (temperature, radiation) and control
electronics, in flexible substrates.
