Numerical simulation of write-operation in a magnetic random access memory cell array with a magnetostatic interaction

The margin for selective write-operation in a current coincident scheme has been numerically evaluated by considering a magnetostatic interaction in a magnetic random access memory cell array. For a conventional method, the margin over 20% cannot be achieved as the cell size is smaller than 0.2×0.4 μ m2. This is mainly attributed to the degradation of field localization created by a conductor current. The minimum cell size ensuring the practical margin can be decreased to 0.16×0.24 μ m2 by using an opposing current flowing through neighboring conductors. The margin is found to be remarkably decreased as a current pulse width becomes less than 0.4 ns because of a gyromagnetic effect.