Kink-free design of submicrometer MRAM cell

Abstract

Full, miromagetic simulations have been performed to investigate the origin of a kink in a magnetoresistive curve and to design a kink-fme magnetoresistive random access memory (MRAM) cell. The kink in an at-field curve can originate from the, 2pi-wall or the vortex formation, which is strongly dependent on the magnetic properties. and the, geometry of a free layer. The kink originating from the 2pi-wall formation was found to disappear in a remanent magnetization curve; therefore, it should not affect the selectivity of a MRAM array. It turned out that the vortex formation-was the major origin of the kink when the free layer has the high saturation magnetization and the thick layer thickness. This vortex state is a local minimum in state even after removing the external field. Finally, we found kink-free criteria for various saturation magnetizations, thicknesses, and aspect ratios of a free layer.