Patent ID: 9608038
Date: 2017-03-28
CPC Classifications: B82Y,G11C,H01F,H01L

Claim:
1. A spin transfer torque magnetic random access memory (STT-MRAM) 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; and a magnetic fixed layer separated from said magnetic reference layer structure by an anti-ferromagnetic coupling layer, wherein 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 an intermediate magnetic reference layer, said first, second, and intermediate magnetic reference layers having a first invariable magnetization direction substantially perpendicular to layer planes thereof, said magnetic fixed layer has a second invariable magnetization direction that is substantially perpendicular to a layer plane thereof and is opposite to said first invariable magnetization direction, said magnetic free layer structure includes one or more magnetic free layers.