MAGNETIC TUNNEL JUNCTION, MAGNETIC RANDOM ACCESS MEMORY, METHOD FOR FORMING VORTEX MAGNETIZATION STATE, AND METHOD FOR SWITCHING VORTEX MAGNETIZATION STATE

摘要

PPROBLEM TO BE SOLVED: To provide an MRAM capable of applying to the purposes of high density and high speed, in which a free layer and a reference layer have a vortex magnetization state. PSOLUTION: A ferromagnetic free layer 27 having the vortex magnetization state with a free rotating direction contains a dopant to reduce an exchange coupling constant. A ferromagnetic pinned layer 25 (reference layer) having the vortex magnetization state with a fixed rotating direction contains the dopant to reduce the exchange coupling constant. Differently from conventional methods using form anisotropy in order to switch the magnetization state, since the magnetization state is switched by using the properties of the film characteristic to a magnetic film such as the exchange coupling constant and Mst (saturation magnetic flux density thickness), large coercive force can be obtained. PCOPYRIGHT: (C)2006,JPO&NCIPI