Fabrication of the nanoscale flat-bottomed and lamellar structures on HOPG surface by STM-based electric lithography

The requirement for fabrication of the nanometer-scale structures has grown up recently due to the advance in the development of the nanoscale electronic-devices or bio-devices. Scanning tunneling microscope (STM)-based electric lithography is one of the potential fabrication approaches to produce nanoscale structures on a variety of materials. This study of the STM-based electric lithography intends to fabricate flat-bottomed and lamellar structures on the graphite surface, which differs from the conventionally fabricated tapered structures. The formation and the comparison of both the lamellar and tapered structures are obtained by applying distinct STM tip geometries in the STM-based electric lithography. On the basis of the experimental results, it is found that the formation of lamellar structures should be attributed to the local electrochemical reaction, while the generation of tapered structures is resulted from the dielectric breakdown in the tip-sample gap. © 2013 Trans Tech Publications Ltd, Switzerland.