MULTIMODE NOISE-ANALYSIS OF CANTILEVERS FOR SCANNING PROBE MICROSCOPY

A multi-mode analysis of micro-cantilever dynamics is presented. We de rive the power spectral density of the cantilever displacement due to a thermal noise source and predict the cantilevers's fundamental reson ant frequency and higher harmonics. The first mode in the multi-mode m odel is equivalent to the traditional single-mode model. Experimental results obtained with a silicon nitride cantilever at 300 K are in exc ellent qualitative agreement with the multi-mode model. The multi-mode model may be used to obtain accurate values of the cantilever propert ies such as the elastic modulus, effective mass, thickness and moment of inertia. (C) 1997 American Institute of Physics.