INTERPRETATION ISSUES IN FORCE MICROSCOPY

In this paper, we will discuss force microscopy (FM) and its potential for determining mechanical properties of thin films. We will introduce the basic principles of FM, and demonstrate how FM can be used to determine materials properties as well as image surface topography, both with nanonewton or sub-nanonewton force resolution and sub-nanometer position resolution. As FM is still a new field, not all of the questions concerning interpretation have been fully answered. We will elucidate four current issues that must be resolved before the full potential of FM can be realized. They are: (1) the role of water vapor and adsorbed films in imaging and force curve measurements, (2) the interpretation of force curves, (3) the influence of surface forces and loads on imaging, and (4) the nature of the imaging mechanisms.