Study of adhesive forces on a silicon nanotip force microscope in contact mode
Résumé
Atomic Force Microscope operating in contact mode is used in this paper for probing the spatial distribution of adhesive forces versus the topography of a silicon nanotip. This nanotip consists in an ultra sha4rp silicon tip with radius less than 15 nm fabricated using a combination of high- resolution electron beam lithography and plasma dry etching. The amplitude of the forces is determined from force versus distance curve measurements. Hence, by determining the contact point and the pull-off force from the force curves, the surface topography and the adhesive forces are simultaneously obtained at various locations on the surface. This paper reports both measurements and the modeling of adhesive forces versus the contact point on the nanotip. As the nanotip is sharper and has got a smaller aperture angle than the employed Atomic Force Microscope tip, the measurements are focused on the nanotip apex.