Patent ID: 7099186
Filing Date: 2006-08-29
Classification: G11C,H01L

Abstract:
1. A method of producing a double-decker magnetoresistive random access memory cell comprising: providing a stacked structure having a first magnetic tunnel junction including first and second magnetic regions made of magnetic material being stacked in a parallel, overlying relationship separated by a first tunneling barrier layer made of non-magnetic material; said first magnetic region of said first magnetic tunnel junction comprising a first pinned layer having a first fixed magnetization adjacent said first tunneling barrier layer, said second magnetic region of said first magnetic tunnel junction exhibiting a first free magnetization adjacent said first tunneling barrier layer which is free to be switched between the same and opposite directions with respect to the first fixed magnetization of said first magnetic region of said first magnetic tunnel junction; said stacked structure further having a second magnetic tunnel junction including third and fourth magnetic regions made of magnetic material being stacked in a parallel, overlying relationship separated by a second tunneling barrier layer made of non-magnetic material; said third magnetic region of said second magnetic tunnel junction comprising a second pinned layer having a second fixed magnetization adjacent said second tunneling barrier layer, said fourth magnetic region of said second magnetic tunnel junction exhibiting a second free magnetization adjacent said second tunneling barrier layer which is free to be switched between the same and opposite directions with respect to the second fixed magnetization of said third magnetic region of said second magnetic tunnel junction; said free magnetizations of said first and second magnetic tunnel junctions being magnetically coupled to magnetic fields generated by first and second currents made to flow through first and second current lines, respectively; and pinning said first fixed magnetization with a first pinning layer made of a first antiferromagnetic material and pinning said second fixed magnetization with a second pinning layer made of a second antiferromagnetic material; antiferromagnetically coupling said first and second pinned layers, the pinned layers having a small intrinsic anisotropy such that a further step is enabled.