Improved selectivity of synthetic anti-ferromagnetic free Layer in high-density MRAM array

We investigate switching characteristics of the patterned submicrometer magnetic tunnel junction (MTJ) cells incorporating with a NiFe single and a synthetic anti-ferromagnetic (SAF) as a free layer. The MTJs with single NiFe free layer show the increased probability of vortex appearance with increase of NiFe thickness. Even though the free layer thickness is decreased, single NiFe free layer shows large variation of switching field. However, the employment of the SAF free layer dramatically improves switching characteristics with the suppression of vortex states and single domain-like tendency.