Fabrication of cantilever with self-sharpening nano-silicon-tip for AFM applications

A simple, high yield method for the fabrication of cantilever with nano-silicon-tip by wet etching for atomic force microscopy (AFM) applications is described in this paper. The nano-silicon-tips with well controlled dimensions are fabricated by self-sharpening anisotropic wet etching technologies using a special pentagon etch mask design. The spring constant of the cantilever according to demand can be easily realized by changing the design of the etch mask and tuning the etching time in the fabrication process. A fabrication yield as high as 90 % has been realized for the AFM probes on 2 inch wafers. The height of tips on the cantilever is 10-15 mu m, and the apex of each nano-silicon-tip typically has a radius of curvature of 5-10 nm. The cantilever's spring constant can be well controlled within the range of 0.8-120 N m(-1). The fabricated AFM probes are capable of generating high quality AFM image comparable with the commercial probes available in our lab.