Atomic force microscopy local oxidation of silicon nitride thin films for mask fabrication

Silicon nitride thin films deposited on silicon substrates are patterned by using atomic force microscopy (AFM) local oxidation nanolithography. The mechanism of the AFM-induced oxidation is studied by analysing the kinetics of the oxidation and by studying the electrical current during the oxidation process. We observe that the silicon substrate and the silicon nitride layer are simultaneously modified. Because of the significant technological relevance of silicon nitride film, the technique is applied for fabricating masks with nanometre-scale features by transferring the pattern to the silicon substrate.