Very Low 1/F Barrier Noise In Sputtered Mgo Magnetic Tunnel Junctions With High Tunneling Magnetoresistance

Low frequency 1/f barrier noise has been investigated in sputtered MgO magnetic tunnel junctions (MTJs) with a tunneling magnetoresistance ratio of up to 330% at room temperature. The lowest normalized noise parameter alpha of the tunnel barrier reaches 2.5 x 10(-12) - 2.1 x 10(-11) mu m(2), which is comparable to that found in MTJs with the MgO barrier grown by MBE or electron-beam evaporation. This normalized barrier noise is almost bias independent in the voltage range of up to +/- 1.2V. The low noise level and high voltage stability may reflect the high quality of the sputtered MgO with a uniform distribution of defects in the MgO layer. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4769805]