Miniaturized single-crystal silicon cantilevers for scanning force microscopy

Abstract

We report on a method to reproducibly batch fabricate single-crystal silicon cantilevers with dimensions an order of magnitude smaller than conventional cantilevers, i.e., with lengths between 10 and 35μm, a width of 4μm, and a thickness of 0.2μm. The cantilevers are attached to support chips specially tailored for use in a scanning force microscope. The resonance frequencies are0.2 – 2 MHz, the spring constants about 0.05−1N∕m, and the quality factors 1.5−3.0×104. The resulting thermal force noise is 1−2×10−16N∕Hz at room temperature in vacuum. These cantilevers allow an enhancement of the measurement speed of more than one order of magnitude, and 2−5× better force sensitivity. After annealing in ultrahigh vacuum and measuring at liquid helium temperature, the thermal force noise of these cantilevers is expected to be further reduced down to 10−18N∕Hz.