Local anodic oxidation by atomic force microscopy (AFM) of thin silicon-nitride layers deposited on silicon wafers allows the definition of stamps for nanoimprint lithography. The study of the mechanism and kinetics of the AFM induced oxidation shows that the patterns on silicon nitride can be generated faster and at lower voltages than directly on silicon surfaces. Stamp fabrication is completed by chemical wet etching of the samples after the AFM patterning, resulting in a robust process because of the excellent properties of silicon nitride as a mask for selective wet etching. As a demonstrator, a stamp for nanoimprint lithography is fabricated that will be used for the realization of biosensors based on interdigitated nanoelectrodes. (c) 2006 American Vacuum Society.