The Influence of the Tip Shape on the STM Scans

摘要

Four different shapes of probe tips are employed to perform scanning experiments on highly ordered pyrolytic graphite samples. I-Z curves and I-V curves for the tunnel current on the surface are obtained and, in the meantime, the influences of tip shape on the height scanning image are analyzed. The results show that tip shape differences have remarkable influences on the sharpness of probe tip, the resolution of the height scanning images increases with the sharpness of probe tip. The requirement for ladder scan level is much lower than that for the atom scan level. Different shapes of probe tips have little effects on the I-V curves for ladder scan. Accordingly, probe tips with only two cuts, which are suitable for ladder scan, can be obtained easily and accurately.