US Patent 9871191 Magnetic random access memory with ultrathin reference layer

The present invention is directed to an MRAM device comprising a plurality of MTJ memory elements. Each of the memory elements includes a magnetic free layer and a first magnetic reference layer with an insulating tunnel junction layer interposed therebetween; a second magnetic reference layer formed adjacent to the first magnetic reference layer opposite the insulating tunnel junction layer; an anti-ferromagnetic coupling layer formed adjacent to the second magnetic reference layer opposite the first magnetic reference layer; and a magnetic fixed layer formed adjacent to the anti-ferromagnetic coupling layer. The magnetic free layer has a variable magnetization direction substantially perpendicular to the layer plane thereof. The first and second magnetic reference layers have a first fixed magnetization direction substantially perpendicular to the layer planes thereof. The magnetic fixed layer has a second fixed magnetization direction that is substantially perpendicular to the layer plane thereof and is substantially opposite to the first fixed magnetization direction.