A nondestructive technique for determining the spring constant of atomic force microscope cantilevers

We present a simple, accurate, and nondestructive method to determine canti lever spring constants by measuring the resonant frequency before and after the addition of a thin gold layer. The method for resonating the cantileve rs uses electrostatic force modulation, which has been described for conduc tive cantilevers, but we demonstrate it can also be applied to silicon nitr ide cantilevers. The variations in spring constant for cantilevers of the s ame type across the same wafer are also explored. (C) 2001 American Institu te of Physics.