Thermal robustness in synthetic antiferromagnetic free layer for magnetic random access memory applications

摘要

We have investigated the magnetic switching properties of synthetic antiferromagnetic (SyAF) structures consisting of Co_(90)Fe_(10)/Ru/Co_(90)Re_(10) structure with a Ru capping layer annealed at 300 deg C. After annealing, the coercivity H_c of the structures with a Co_(90)Fe_(10) thickness below 5 nm increased. On the other hand, the H_c was maintained below 70 Oe in structures with a Co_(90)Fe_(10) thickness above 6 nm after annealing. Thus, a low switching field for a free layer can be achieved by using the SyAF structures with a Ru capping layer, even after annealing at 300 deg C, and the SyAF free layer is considered to be effective for downsized memory cells in magnetic random access memories.