We have developed an in situ focused ion beam measurement technique, which
has applications for the accurate, controlled, and reproducible removal of
material for high aspect ratio nanometer scale cuts in tracks. This techniq
ue uses the resistance change of a track, as it is milled by ions, to monit
or in real time the thickness and the end point. We have compared this tech
nique with the thickness measurements by atomic force microscope for 1 mu m
wide cuts. The technique has an accuracy of a few nanometers. (C) 2000 Ame
rican Vacuum Society. [S0734-211X(00)02802-X].