Ultra-high thermal stability of perpendicular magnetic anisotropy in the W buffered CoFeB/MgO stacks with Zr dusting layers

Practical device applications of magnetic multilayers with perpendicular magnetic anisotropy (PMA) usually need to match the mature complementary metal-oxide-semiconductor (CMOS) integrated techniques, which require high temperature annealing during the back-endof-line process. Here, we report the realization of PMA in the W buffered CoFeB/MgO stack by inserting a thin Zr dusting layer between CoFeB and MgO layers. An ultra-high thermal stability of PMA in the W/CoFeB/Zr/MgO stack is observed, which is robust upon annealing at 600 degrees C. The establishment of PMA in W/CoFeB/Zr/MgO is due to the formation of an interface layer between CoFeB and MgO doped with oxidized Zr. After annealing at 540 degrees C, the magnetic interfacial anisotropy density reaches 3.08 erg/cm(2), which is much higher than those in previous reports. The results suggest that the W/CoFeB/Zr/MgO stack with extra high annealing stability is a potential candidate to achieving the practical application of spin-logic device that is compatible with the mature CMOS integrated techniques. Published under an exclusive license by AIP Publishing.

Automated summary

In this study, the realization of PMA in a W buffered CoFeB/MgO stack is achieved by inserting a thin Zr dusting layer between the CoFeB and MgO layers. An ultra-high thermal stability of PMA in the W/CoFeB/Zr/MgO stack is observed, making it a potential candidate for practical applications of spin-logic devices compatible with mature CMOS integrated techniques.