Sharp GaN nanowires used as field emitter on active cantilevers for scanning probe lithography

Field emission scanning probe lithography (FE-SPL), which offers sub-10 nm resolution under ambient conditions, strongly relies on the quality and shape of the applied scanning probe tip. The technological development of AFM systems is also strongly connected to the performance of the cantilever. Thereby, the probes evolved from a simple passive deflection element to a complex MEMS through integration of functional groups, such as piezoresistive detection sensors and bimaterial based actuators. Here, the authors show actual trends and developments of miniaturization efforts for fabrication of active cantilevers with mounted sharp GaN and diamond nanowires. Both materials exhibit a higher mechanical stability than the typically applied silicon, which is supposed to increase tip lifetime and reproducibility of the lithography process. Furthermore, diamond offers a high chemical stability, whereas electrical and optical properties of GaN are tunable. They present preliminary results on the applicability of GaN nanowires and diamond tips, mounted on active scanning probes, as field emitter for FE-SPL. Therefore, field emission measurements, stability of field emission current, and exemplary high resolution features generated with the tested tips are shown.