High TMR dual-MTJ STT-MRAM design with perpendicular magnetic anisotropy (Conference Presentation)

STT-MRAM cell design with dual magnetic tunnel junctions (D-MTJ) is a novel design that show a factor of ~2 in switching performance compared to conventional MRAM design. However, the disadvantage is D-MTJ tends to show lower TMR. In this presentation, we demonstrate it's possible to achieve high TMR D-MTJ cell design without compromising its performance gain. We accomplished this by thinning down the secondary MgO barrier. We observe that when thinning down the secondary barrier, the device level TMR reaches a level close to conventional MRAM design of the same free layer while still preserving its high switching performance