A lithographic approach of spatial separation for multiple types of layer-by-layer self-assembled nanoparticles

A lithographic approach is presented to pattern two types of nanoparticles on one 4 inch silicon wafer. The different nanoparticles are separated completely according to the designed pattern. The process is applicable to all types of nanoparticles, which may enable its application in complex device fabrication that requires more than one type of functional nanoparticles. The process is quite simple, consisting of only two consecutive lift-offs, and there is no high requirement for the equipments. 150 nm and 64 nm polystyrene particles were selected in the experiment as two different particles. A scanning electron microscope was used to observe the patterns comprised of two types of polystyrene nanoparticles.