Magnetic random access memory having perpendicular enhancement layer

摘要

The present invention is directed to a spin transfer torque (STT) MRAM device having a perpendicular magnetic tunnel junction (MTJ) memory element. The memory element includes a perpendicular MTJ structure in between a non-magnetic seed layer and a non-magnetic cap layer. The MTJ structure comprises a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween, an anti-ferromagnetic coupling layer formed adjacent to the magnetic reference layer structure, and a magnetic fixed layer formed adjacent to the anti-ferromagnetic coupling layer. At least one of the magnetic free and reference layer structures includes a non-magnetic perpendicular enhancement layer, which improves the perpendicular anisotropy of magnetic layers adjacent thereto.

主权项

1. A magnetic random access memory device comprising a plurality of memory elements, each of said memory elements including a magnetic tunnel junction (MTJ) structure in between a non-magnetic seed layer and a non-magnetic cap layer, said MTJ structure comprising a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween, wherein said magnetic free layer structure includes a first magnetic free layer formed adjacent to said insulating tunnel junction layer and a second magnetic free layer separated from said first magnetic free layer by a first non-magnetic perpendicular enhancement layer (PEL), said magnetic reference layer structure includes a first magnetic reference layer formed adjacent to said insulating tunnel junction layer and a second magnetic reference layer separated from said first magnetic reference layer by a second non-magnetic perpendicular enhancement layer, said first and said second magnetic free layers have respectively a first and a second variable magnetization directions substantially perpendicular to layer planes thereof, said first and second magnetic reference layers have a first fixed magnetization direction substantially perpendicular to layer planes thereof.