PREPARATION OF PROBE TIPS WITH WELL-DEFINED SPHERICAL APEXES FOR QUANTITATIVE SCANNING FORCE SPECTROSCOPY

A method for the preparation of scanning force microscopy (SFM) tips w ith spherically shaped tip apexes and known tip radii by exposing comm ercially available silicon cantilevers to the electron beam of a trans mission electron microscope is presented. The spherical shape of the t ip apexes was achieved by growth of a contamination layer at the end o f the tip using the electron-beam deposition process. Well-defined rad ii between 7 and 120 nm could be produced. The importance of such tips for quantitative SFM measurements is discussed. Topographical measure ments on a special test sample are shown as well as measurements of th e frictional force as a function of the loading force as an example fo r quantitative spectroscopical measurements. (C) 1997 American Vacuum Society. [S0734-211X(97)02004-0].