Magnetic random access memory with perpendicular interfacial anisotropy

摘要

The present invention is directed to an MRAM element comprising a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween. The magnetic free layer structure has a variable magnetization direction substantially perpendicular to the layer plane thereof. The magnetic reference layer structure includes a first magnetic reference layer formed adjacent to the insulating tunnel junction layer and a second magnetic reference layer separated from the first magnetic reference layer by a first non-magnetic perpendicular enhancement layer. The first and second magnetic reference layers have a first fixed magnetization direction substantially perpendicular to the layer plane thereof. The second magnetic reference layer has a multilayer structure comprising a first magnetic reference sublayer formed adjacent to the first non-magnetic perpendicular enhancement layer and a second magnetic reference sublayer separated from the first magnetic reference sublayer by an intermediate metallic layer.

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 has a variable magnetization direction substantially perpendicular to a layer plane thereof, 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 first non-magnetic perpendicular enhancement layer, said first and second magnetic reference layers having a first fixed magnetization direction substantially perpendicular to layer planes thereof, said second magnetic reference layer having a multilayer structure comprising a first magnetic reference sublayer formed adjacent to said first non-magnetic perpendicular enhancement layer and a second magnetic reference sublayer separated from said first magnetic reference sublayer by an intermediate metallic layer, said first and second magnetic reference sublayers having said first fixed magnetization direction.