Dependence of transport rate on area of lithography and pretreatment of tip in dip-pen nanolithography.

This study examines the lithographic capacity of tips in dip-pen nanolithography (DPN). The dependence of the transport rate (R) decay on the area of lithography (A(lith)), the dependence of A(lith) on the lithographic time (t), and the effect of piranha cleaning on the lithographic capacity are considered herein. The dependencies in the line-drawing lithography process are studied using 16-mercaptohexadecanoic acid (MHA) ink. On the basis of the linear decay dependence discovered in the R-A(lith) dependence, piranha treatment can increase the lithographic capacity by up to 35.5-fold, an improvement that may originate from a change in the tip's surface chemistry. Moreover, a theoretical model is derived to describe the A(lith)-t dependence accurately and to predict the tips' lifetime. Furthermore, an experiment involving DPN-based nanostructure fabrication demonstrates the importance of monitoring the tips' transport rate and lifetime. In addition to shedding light on the physical and chemical principles behind DPN, this study provides a comprehensive model for a quantitative analysis of the tips' behavior.