Characterization of the electrical and magnetic properties of sub-micron MTJ cells using scanning probe microscope interfaced with an external magnetic field generator

Tunneling current behaviors of magnetic tunneling junction (MTJ) cells were studied utilizing scanning probe microscopy (SPM) interfaced with an external magnetic field generator. The I–V measurement was made at contact mode using a conducting cantilever at a specific magnetic field. Magnetoresistance (MR) ratios of the the MTJ cells were determined as 20–21% regardless of the variation in the size of the MTJ cells, and RA which is the resistance value multiplied by the area and equals 8.5–12.5 K [kVmm2]. We also observed the magnetic images of the MTJ cells under various magnetic fields to understand the anomalous behaviors in hysteresis loops. The vortices were found to be located at the end zone of the MTJ cell, and it played an important role to cause such anomalous two-step magnetic switching.