Coaxial tip piezoresistive scanning probes for high-resolution electrical imaging

We have designed and batch fabricated silicon cantilever scanning probes integrating, for the first time, a coaxial tip to produce highly localized electric fields and a piezoresistor to measure cantilever deflection. These probes will improve the lateral resolution of scanning gate microscopy enabling the study of electron organization in semiconductor nanostructures. The full-width at half-maximum of the perturbation produced by our coaxial tip is ~3x smaller than that of conventional tips. At 300 K, the vertical displacement resolution of a 405 ¿m long probe is 2.4 nm in a 1 kHz bandwidth. With the ability to image topography and apply local electric fields, our probe has broad applications including electromechanical studies of cells and dopant profiling in semiconductors.