MAGNETIC RANDOM ACCESS MEMORY HAVING PERPENDICULAR ENHANCEMENT LAYER AND INTERFACIAL ANISOTROPIC FREE 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 magnetic tunnel junction (MTJ) memory elements, each of said memory elements comprising:
a magnetic free layer structure including a first and a second magnetic free layers with a tantalum perpendicular enhancement layer interposed therebetween, said first magnetic free layer comprising cobalt, iron, and boron, said first and said second magnetic free layers having respectively a first and a second variable magnetization directions substantially perpendicular to layer planes thereof; a non-magnetic metal layer made of platinum or palladium in contact with said second magnetic free layer opposite said tantalum perpendicular enhancement layer; and an insulating tunnel junction layer formed adjacent to said first magnetic free layer opposite said tantalum perpendicular enhancement layer.