High speed scanning for dynamic atomic force microscope based on higher-order resonance of silicon cantilever

On the basis of higher-order resonant characteristics of silicon cantilevers of Atomic Force Microscopes (AFMs), a high speed scanning method for dynamic AFMs based on the higher-order resonant cantilever was put forward, and an AFM working at one-order resonant and higher-order modes was developed. The basic structure and working principle of the higher-order resonant AFM system were introduced and the feasibility of the method by using the higher-order resonant characteristics of cantilever to realize high speed scanning was demonstrated theoretically. With home-built AFM as the investigated object, the main factors influencing the scanning speed of the dynamic AFM were investigated, and the response time of each system module was analyzed and estimated by tests. It is experimentally proven that the settling time of the second-order resonant mode AFM is less than that the first-order resonant mode AFM obviously. Finally, the same area of a grating sample was scanned by the first-order and the second-order mode AFMs respectively and the experimental results demonstrate that the scanning speed of the second-order mode AFM is about 3.3 times faster than that of the first-order resonant mode under the same condition. Theoretical analysis and experimental results prove the feasibility and effectiveness to improve the dynamic AFM scanning speed by using the higher-order resonant cantilever.