AVS 46th International Symposium
    Applied Surface Science Division Monday Sessions
       Session AS-MoM

Paper AS-MoM5
Geometry and Tip Effect Simulation in Scanning Kelvin Probe Microscopy

Monday, October 25, 1999, 9:40 am, Room 6A

Session: Imaging and Small Area Analysis
Presenter: A.E. Efimov, Silicon-MDT Ltd., Russia
Authors: A.E. Efimov, Silicon-MDT Ltd., Russia
S.R. Cohen, Weizmann Institute of Science, Israel
I. Visoly, Weizmann Institute of Science, Israel
D. Cahen, Weizmann Institute of Science, Israel
Correspondent: Click to Email
Scanned probe microscopy (SPM) techniques have become an integral part of the fabrication and study of miniaturized devices, as well as of nm-scale features in general. Well-known geometric effects of tip size have been studied and several solutions were proposed for their removal from obtained topographical images. A more subtle effect exists for electronic surface mapping using such modes as scanning Kelvin probe microscopy (SKPM). These effects become significant for high resolution work on surfaces whose topography is not flat. We demonstrate this phenomenon on SKPM studies of CdTe films which exhibit both rich topography and electronic structure at grain boundaries. II-VI semiconductors exhibit interesting electronic properties which not only allow their applications in miniaturized electronic device structures, but suggests their study as model systems as an end in itself. A combined theoretical and computational approach is used to simulate the SKPM imaging process, calculate geometric contributions and separate electronic features from geometric distortions in the scanned probe images, in an attempt to recover the surface potential and therefore move towards true SKPM imaging. The results are compared with parallel techniques, such as scanning tunneling spectroscopy (STS), where the geometric contributions can be effectively ignored.