Characterization of domain switching behavior of MTJ cells using magnetic force microscopy(MFM) and H-R loop analysis

Correlationship between electrical and magnetic properties of magnetic tunnel junction (MTJ) for Magnetic Random Access Memory(MRAM) was studied. MTJ (Ta/NiFeCr/PtMn/CoFe/Ru/CoFe/AlOx/CoFe/NiFe/Ta) was analyzed utilizing H-R loop and MFM images. We verified that the kink in H-MR loop comes from the vortex domain of free layer. In addition, we also observed a close relationship between domain switching behavior and anomalous H-R curve. These results would be useful for characterization of MTJ cell, thereby optimizing the process to realize the ultra high density MRAM