MAGNETIC TUNNEL JUNCTION STRUCTURE WITH PERPENDICULAR MAGNETIC ANISOTROPY

摘要

A magnetic tunnel junction (MTJ) structure with perpendicular magnetic anisotropy is provided. The MTJ structure with the perpendicular magnetic anisotropy comprises: a first seed layer which is formed of a multi-thin film wherein a first nonmagnetic material and a diffusion prevention material are repeatedly layered by turns; a second seed layer which is located on the first seed layer and includes a second nonmagnetic material; a first ferromagnetic layer which is located on the second seed layer and has perpendicular magnetic anisotropy; a tunneling barrier layer located on the first ferromagnetic layer; and a second ferromagnetic layer which is located on the tunneling barrier layer and has perpendicular magnetic anisotropy. The diffusion prevention material is combined to the first and second nonmagnetic materials to prevent the first and second nonmagnetic materials from being thermally diffused to the first ferromagnetic layer at a temperature of 350°C to 400°C. Thus, the crystalline structure of the first ferromagnetic layer can be maintained in a high temperature of 350°C to 400°C by using a tungsten series material as a seed layer material. The MTJ structure with improved thermal stability can be provided to prevent problems associated with reduced perpendicular magnetic anisotropy.