Double magnetic tunnel junctions with perpendicular anisotropy

Magnetic Tunnel Junctions (MTJs) with perpendicular anisotropy have been studied extensively in recent years since their remarkable properties (high write speed, scalability, endurance, low critical current density for Spin Transfer Torque (STT) switching, etc.) make them particularly attractive components to use in Magnetic Random Access Memories (MRAM). In the meantime, the use of a double barrier in planar junctions appeared to enhance STT efficiency and reduce the bias dependence of Tunnel MagnetoResistance (TMR). In this study, we investigate the realization of double magnetic tunnel junctions with double polarizers and perpendicular anisotropy. The first step consists in studying the anisotropy of a FeCoB storage layer capped with MgO in a standard MTJ with bottom Synthetic AntiFerromagnetic (SAF) reference obtained through RKKY coupling. It is then used in a complete stack with optimized bottom and top reference layers. This stack allows for the reference layers to be set in opposite or in the same direction.