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 μm × 10 μm. Their TMR values and resistance-area products are about 121% and 61 kΩμm2, respectively. A comparison of AFM data simultaneously obtained with a self-sensing cantilever with a 37 μm × 37 μm large TMR sensor and the conventional optical beam deflection method revealed the same data quality.