ReaxFF molecular dynamics simulation study of nanoelectrode lithography oxidation process on silicon (100) surface

The nanoelectrode lithography has been strengthened in recent years as one of the most promising methods due to its high reproducibility, low cost and ability to manufacture nano-sized structures. In this work, the mechanism and the parametric influence in nanoelectrode lithography have been studied qualitatively in atomic scale using ReaxFF MD simulation. This approach was originally developed by van Duin and co-workers to investigate hydrocarbon chemistry. We have investigated the water adsorption and dissociation processes on Si (100) surface as well as the characteristics (structure, chemical composition, morphology, charge distribution, etc.) of the oxide growth. The simulation results show two forms of adsorption of water molecules: molecular adsorption and dissociative adsorption. After breaking the adsorbed hydroxyls, the oxygen atoms insert into the substrate to form the Si-O-Si bonds so as to make the surface oxidized. The influence of the electric field intensity (1.5-7 V/nm) and the relative humidity (20-90%) on the oxidation process have also been discussed. Nevertheless, the results obtained from the simulations have been compared qualitatively with the experimental results and they show in good agreements. Variable charge molecular dynamics allowed us to characterize the nanoelectrode lithography process from an atomistic point of view.