Nanometer-scale conversion of Si3N4 to SiOx

It has been found that atomic force microscope (AFM) induced local oxidatio n is an effective way for converting thin (< 5 nm) Si3N4 films to SiOx. The threshold voltage for the 4.2 nm film is as low as 5 V and the initial gro wth rate is on the order of 10(3) nm/s at 10 V. Micro-Auger analysis of the selectively oxidized region revealed the formation of SiOx. Due to the lar ge chemical selectivity in various etchants and great thermal oxidation rat e difference between Si3N4, SiO2, and Si, AFM patterning of Si3N4 films can be a promising method for fabricating nanoscale structures. (C) 2000 Ameri can Institute of Physics. [S0003-6951(00)03003-5].