No 2, Vol. 4, 2001 
 

EFFECTS OF STM TIP MOVEMENT TO THE REAL WIDTH OF
AN ELECTRIC PULSE ACTING ON THE GAP BETWEEN THE TIP
AND THE SAMPLE SURFACE

C. Z. Cai, W. L. Wang, X. Y, Chen and Q. Q. Shu

Department of Applied Physics, Chongqing University,
Chongqing 400044, P. R. China

Abstract

During the process of nano-lithography on solid material surfaces by a Scanning Tunneling Microscope (STM) system working at constant current mode, while a high-voltage electric pulse acts on the gap between the tip and the sample surface, the feedback circuit causes the tip to withdraw swiftly, resulting in a reduction of effective pulse-width. In the experiment presented in this paper, a specially designed and computer controlled temporary "holding" function can maintain the tip position and the tip-sample distance during the whole period when the high-voltage pulse acts, so that the effective pulse-width can be accurately measured. An experiment of lithography on a graphite surface in air found, for the first time, the threshold of effective pulse-width to be (0.04±0.01)µS, with a voltage amplitude of 4V.

Keywords: nano-lithography, scanning tunneling microscope, graphite surface

full paper (pdf, 128 Kb)