Mechanical nanolithography without solvents - a step towards sustainable nanomanufacturing

In the post-Moore's law era, innovative new technologies to accelerate scientific computing and memory devices are growing explosively, amongst which photonic memory devices have been attracting a great amount of interest and hold future promise for built-in, non-volatile memory with high density, fast switching, multifunctionality, low-energy consumption, and multilevel data storage compared to electronic memory devices. It is now timely to ensure that these new device concepts are developed alongside new sustainable processes - as it is in the introduction stage of new products that manufacturing processes can also be changed.

Current manufacturing of high-resolution semiconductor devices primarily relies on photolithography as the patterning technique of choice. During the fabrication of these resist-based lithography techniques, development and lift-off steps utilize alkaline solutions and organic solvents as developers and removers. These are two of the main sources of hazardous chemical wastes . The US Environmental Protection Agency developed a waste management hierarchy, which states that the most preferred approach is source reduction and reuse, followed by recycling, energy recovery, treatment and disposal. Therefore, the development of a water-based manufacturing technique which limits the amount of hazardous chemicals at the source is essential to the minimization of chemical wastes. This will lead to higher resource efficiency and more efficient recycling and recovery of processing waste.

That is precisely what this proposal will target. The vision is to develop facile, inexpensive, scalable solvent-free lithography for nanomanufacturing, which eliminates solvents in as many lithography processes as possible but doing this in a reliable and functionally enabling manner.