Effect of high annealing temperature on giant tunnel magnetoresistance ratio of CoFeB/MgO/CoFeB magnetic tunnel junctions

Abstract

We report tunnel magnetoresistance (TMR) ratios as high as 472% at room temperature and 804% at 5 K in pseudo-spin valve (SV) CoFeB/MgO/CoFeB magnetic tunnel junctions (MTJs) annealed at 450oC, which is approaching the theoretically predicted value. By contrast, the TMR ratios for exchange-biased (EB) SV MTJs with a MnIr antiferromagnetic layer are found to drop when they are annealed at 450oC. Energy dispersive X-ray analysis shows that annealing at 450oC induces interdiffusion of Mn and Ru atoms into the MgO barrier and ferromagnetic layers in EB-SV MTJs. Mechanisms behind the different annealing behavior are discussed.

13 pages, 5 figures

References in corpus (1)

• Giant tunnel magnetoresistance and high annealing stability in CoFeB/MgO/CoFeB magnetic tunnel junctions with synthetic pinned layer

Cited by in corpus (4)

• Bias-driven large power microwave emission from MgO-based tunnel magnetoresistance devices
• Oxide spintronics
• Current-induced magnetization switching in MgO barrier magnetic tunnel junctions with CoFeB based synthetic ferrimagnetic free layers
• Strong temperature dependence of antiferromagnetic coupling in CoFeB/Ru/CoFeB