6-MHz 2-N/m piezoresistive atomic-force-microscope cantilevers with INCISIVE tips

Piezoresistive atomic-force-microscope (AFM) cantilevers with lengths of 10 mu m, displacement sensitivities of (Delta R/R)/Angstrom = 1.1 x 10(-5), displacement resolutions of 2 x 10(-3) Angstrom/root Hz mechanical response times of less than 90 ns, and stiffnesses of 2 N/m have been fabricated from a silicon-on-insulator (SOI) wafer using a novel frontside-only release process, To reduce mass, the cantilevers utilize novel inplane crystallographically defined silicon variable aspect-ratio (INCISIVE) tips with radius of curvature of 10 Angstrom. The cantilevers have been used in an experimental AFM data-storage system to read back data with an areal density of 10 Gb/cm(2), Four-legged cantilevers with both imaging and thermomechanical surface modification capabilities have been used to write 2-Gb/cm(2) data at 50 kb/s on a spinning polycarbonate sample and to subsequently read the data. AFM imaging has been successfully demonstrated with the cantilevers. Some cantilever designs have sufficient displacement resolution to detect their own mechanical-thermal noise in air, The INCISIVE tips also have applications to other types of sensors.