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Thursday, 28 September 2017 at 3:15 pm

McCullough, First Floor Auditorium, Room #115

Host:  Yuri Suzuki 

Daniel Worledge

IBM Almaden Research Center


Spin-Transfer-Torque MRAM

 Spin-Transfer-Torque MRAM was invented at IBM by John Slonczewski in the early 1990s.  By using a spin-polarized current, instead of a magnetic field, to write a magnetic free layer in a magnetic tunnel junction, the required write current naturally decreases with area, providing attractive technology scaling.  The discovery of high magnetoresistance in MgO tunnel barriers at IBM by Stuart Parkin, and later independently by Shinji Yuasa, enabled sufficient read signal to efficiently read magnetic tunnel junctions.  The discovery of perpendicular magnetic anisotropy in thin CoFeB/MgO layers at IBM and independently by Tohoku University enabled a dramatic reduction in the switching current, and opened the way to practical perpendicular magnetic tunnel junctions for dense Spin-Transfer-Torque MRAM.

This talk will review these basic building blocks and then discuss our recent results on methods to lower the switching current of Spin-Transfer-Torque MRAM by using optimized magnetic materials and double magnetic tunnel junctions.