Self-sensing atomic force microscopy cantilevers based on tunnel magnetoresistance sensors

Abstract

Here, we introduce self-sensing cantilevers for atomic force microscopy (AFM) based on tunnel magnetoresistance (TMR) sensors. These TMR sensors are integrated into the AFM cantilevers and consist of a magnetically stable layer and a sensing magnetostrictive CoFeB layer separated by a MgO tunneling barrier and can be as small as 10 mu m x 10 mu m. Their TMR values and resistance-area products are about 121% and 61 k Omega mu m(2), respectively. A comparison of AFM data simultaneously obtained with a self-sensing cantilever with a 37 mu m x 37 mu m large TMR sensor and the conventional optical beam deflection method revealed the same data quality. (C) 2013 AIP Publishing LLC [http://dx.doi.org/10.1063/1.4801315]