NANOMETER-SCALE LITHOGRAPHY ON H-PASSIVATED SI(100) BY ATOMIC-FORCE MICROSCOPE IN AIR

We report on the mechanical friction method for a fabrication of a Si nanostructure on a H-passivated Si(100) substrate using an atomic forc e microscope (AFM) in a contact mode in air. The bare Si surface regio n exposed by the mechanical friction between a silicon nitride tip and Si surface was fully oxidized by ambient oxygens. The oxide mask patt erns could withstand a selective wet etching process for pattern trans fer. The width of the oxide layer formed by an AFM tip was about 200 A ngstrom. As the etching time and scan rate were decreased, the oxide l ine shape was improved. This study also showed that there exists a cri tical tip force in the removal of a H-passivating layer. (C) 1997 Amer ican Vacuum Society.