Preparation of nano-scale patterns on the silicon oxide surface by dip-pen nanolithography

Dip-pen nanolithography (DPN), which uses un "inked" AFM tip to deposit organic molecules through a water meniscus onto an underlying substrate under ambient conditions, has been used to create N-(2-aminoethyl)-3-amino-propyl-trimethoxysilane (AEAPTMS) nano patterns as linkers for anchoring gold nanoparticles on the surface of SiO₂. In this study, conditions of DPN for organic patterns, AEAPTMS, with sub-100 nm dimensions are investigated. Moreover, gold nanoparticles with citrate-negatively-charged surface were deposited selectively on top of DPN organic patterns. Lateral force microscope (LFM) was utilized to differentiate different surface between oxidized semiconductor surfaces and patterned areas with monolayer of AEAPTMS. Line-width as small as 60 nm has been successfully achieved by this method.