All the lithographic techniques have a cost-dependent resolution. As resolution increases, fabrication complexity and system costs rise significantly. nano analytik GmbH developed a new cost-effective Field emission- Scanning Probe Lithography (FE-SPL) System operating at ambient or under vacuum conditions.

FE-SPL tool is based on the low-energy Fowler-Nordheim (FN) electron field-emission from ultra-sharp scanning probe tips placed in close proximity to a resist-covered specimen. In contrast to conventional electron beam lithography (EBL), FE-SPL operates with low-energy electrons below 100 eV, minimizing electron penetration depth, backscattering, substrate heating, and radiation damage while improving exposure efficiency and resist sensitivity and enabling highly localized nanoscale patterning. This enables routine sub-5 nm patterning on planar and non-planar surfaces and makes the technology particularly suitable for delicate ultra-thin materials such as graphene and TMDCs, which can otherwise be damaged by high-energy electrons in EBL or ultraviolet exposure in optical lithography.

The closed-loop FE-SPL architecture supports “mix and match” lithography workflows in combination with optical lithography and EBL, enabling improved overlay accuracy, reproducibility, and throughput. The combination of AFM imaging and FE-SPL lithography enables high-resolution nanoscale fabrication for advanced nanoelectronic devices. FE-SPL has been used for the fabrication of single electron transistors (SETs) operating at room temperature (RT-SETs). Such SETs are a starting point for the realisation of atomic scale devices. Especially, we exploit the confinement of the potential well, created by an embedded dopant atom ( P, As or B) in an insulator, due to high tunnel barriers of SiO2.