Demonstration of a Free-layer Developed With Atomistic Simulations Enabling BEOL Compatible VCMA-MRAM with a Coefficient ≥100fJ/Vm
R. Carpenter, W. Kim, Kiroubanand Sankaran, Niqi Ao, Mohamed Ben Chroud, Ankit Kumar, A. Trovato, Geoffrey Pourtois, Sébastien Couet, Gouri Sankar Kar
Abstract
For the first time in voltage control of magnetic anisotropy magnetic random-access memory (VCMA-MRAM), a large coefficient of ≥ 100 fJ/Vm has been demonstrated in fully integrated, BEOL compatible, magnetic tunnel junctions (MTJ). This was achieved while maintaining a high TMR (180%) and thermal stability factor ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\Delta > 40$</tex> ). VCMA-induced switching is also explored, showing the benefits for low power and ultrafast memory applications. This was enabled thanks to the development of a VCMA-MRAM specific free-layer (FL) which incorporates the insertion of transition metals at the CoFeB|MgO interface. The design of this FL was driven by atomistic simulations using an imec developed, non-perfect epitaxial stack model.