ACOUSTIC AND DYNAMIC FORCE MICROSCOPY WITH ULTRASONIC PROBES

Ultrasonic quartz resonators with quality factors >5000 allow one to p robe surface morphologies directly, i.e., without any additional senso rs determining the vertical position of the probing tip. With tip radi i of several tenths of a micrometer, hydrodynamic friction forces domi nate the tip/surface interaction. while, by using sharp atomic force m icroscopy tips glued onto rod-shaped 1 MHz length extension quartz res onators, the conventional dynamical quasi noncontact atomic force micr oscopy mode is obtained. This allows one to resolve atomically sized s tructures on mica in air. The ultrasonic sensors with spring moduli of 3000 to 400 000 N/m exhibit an extremely high sensitivity allowing on e to probe even monomolecular organic layers without destruction. (C) 1996 American Vacuum Society.