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 α of the tunnel barrier reaches 2.5 × 10-12-2.1 × 10-11 μm2, 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 ±1.2 V. 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. [ABSTRACT FROM AUTHOR]