Surface characterization with nanometer lateral resolution using the vibration modes of atomic force microscope cantilevers

The combination of ultrasound with atomic force microscopy (AFM) opens the high lateral resolution of scanning probe echniques to ultrasonics. Atomic force acoustic microscopy (AFAM) and lateral atomic force acoustic microscopy are techniques which use the vibration modes of AFM cantilevers. In the AFAM-mode the cantilever is vibrating in one of its flexural resonances while the sensor tip is continuously in contact with the sample surface. With this imaging technique a contrast can be obtained which depends on the elasticity of the sample surface. Quantitative values of a local elastic constant can be obtained. Shear stiffness and friction phenomena can be investigated in ultrasonic friction force microscopy by evaluating the torsional resonances of AFM cantilevers.