Imaging Nanometer Scale Defects in Langmuir-Blodgett Films with the Atomic Force Microscope

Atomic force microscope (AFM) imaging of cadmium arachidate and other Langmuir-Blodgett (LB) films provides a straightforward and nondestructive new technique for determining the quality of LB films. An AFM operating in air has been used to image the surface, defects, and thickness of cadmium arachidate monolayers deposited on mica. Holes in cadmium arachidate monolayers as small as 10 nm can be seen. New holes can be scraped in both old and new monolayers by increasing the applied force on the AFM tip to a point where the underlying mica lattice could be seen. In this way, we can directly measure the thickness of the monolayer. Using the AFM to make patterned holes in LB films has potential applications to nanolithography.