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公开(公告)号：GB2520429A
公开(公告)日：2015-05-20
申请号：GB201419724
申请日：2014-11-05
Applicant: IBM , CROCUS TECHNOLOGY SA
Inventor： ANNUNZIATA ANTHONY JOSEPH , TROUILLOUD PHILIP LOUIS , WORLEDGE DANIEL CHRISTOPHER , BANDIERA SEBASTIEN , LOMBARD LUCIEN , PREJBEANU LUCIAN
Abstract: A thermally assisted magnetoresistive random access memory device (TAS-MRAM) with reduced power for reading and writing; the memory device comprising a tunnel barrier 14 sandwiched between a ferromagnetic sense layer 16 and a ferromagnetic storage layer 12. An antiferromagnetic pinning layer 30 is disposed adjacent to the ferromagnetic storage layer 12. The pinning layer 30 pins a magnetic moment of the storage layer until heating is applied. Either or both of the storage and sense ferromagnetic layers includes a non-magnetic material to reduce the magnetization of the respective layers. The reduction in the storage layer magnetization and sense layer magnetization reduces the magnetostatic interaction between the storage layer and sense layer, resulting in less read/write power. The ferromagnetic materials in the sense and storage layers may include at least one of Co, Fe, Ni, and any alloy including Co, Fe, Ni, whilst the non-magnetic material includes at least one of Ta, Ti, Hf, Cr, Nb, Mo, Zr and any alloy containing Ta, Ti, Hf, Cr, Nb, Mo, Zr. The antiferromagnetic pinning layer may have a diameter less than 250nm based on the reduction in magnetization of at least one of the storage or sense layer. The ferromagnetic storage layer may be formed by sputtering ,chemical vapour (vapor) deposition CVD or physical vapour deposition PVD , and may involve co-sputtering the ferromagnetic and non magnetic material, or forming multi-layers of ferromagnetic and non magnetic material. The ferromagnetic sense layer may also be formed by co-sputtering of ferromagnetic and non magnetic material or forming multilayers of the two materials. An alternative embodiment (figures 7A/B) comprises a tunnel barrier layer 14 sandwiched between a ferromagnetic storage layer 16 and a synthetic antiferromagnetic storage layer 12, which includes a first ferromagnetic storage layer 11 adjacent to the tunnel barrier layer and a non magnetic coupling layer 15 sandwiched between the first ferromagnetic storage layer 11 and a second ferromagnetic storage layer 13. The alternative structure further allows for a relative increase in the thickness of the first ferromagnetic layer 11.
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公开(公告)号：GB2528806A
公开(公告)日：2016-02-03
申请号：GB201517577
申请日：2014-11-05
Applicant: IBM
Inventor： ANNUNZIATA ANTHONY JOSEPH , TROUILLOUD PHILIP LOUIS , WORLEDGE DANIEL CHRISTOPHER , BANDIERA SEBASTIEN , LOMBARD LUCIEN , PREJBEANU LUCIAN
Abstract: A thermally assisted magnetoresistive random access memory device (TAS-MRAM or Thermal MRAM). The device operates as a magnetic tunnel junction (MTJ) which comprises a tunnel barrier junction 14 sandwiched between a sense ferromagnetic layer 16 and a synthetic antiferromagnetic layer (SAF) 12 which acts as a storage layer. SAF layer comprises two proximate ferromagnetic layers 11, 13 separated by a non magnetic coupling layer 15 (ruthenium Ru). Adjacent to the SAF layer is a pinning layer 30 which fixes the magnetic orientation of the antiferromagnetic layers in normal operation but when electrically heated during the write cycle, unpins the magnetic orientations of the SAF ferromagnetic layers allowing programming of the TAS-MRAM MTJ device, by an adjacent magnetic filed 80. The ferromagnetic material may comprise Co, Fe, Ni or any alloys of these elements. At least one of the ferromagnetic layers in the ferromagnetic sense layer or in the constituents of the synthetic antiferromagnetic layer may comprise a non magnetic material acting as dopants, for example Ta, Ti, Hf, Cr, Nb, Mo or Zr or alloys of these elements. The doped ferromagnetic layers may be formed from sputtering, co-sputtering and may also form layers or a laminate (figures 8A-C). The ensuing reduction in the magnetostatic interaction dispersions between the relative ferromagnetic sense and storage layers leads to a reduction in reading or writing power consumption. It also allows a relatively larger thickness for each or any of the ferromagnetic layers, which may within the range 10Ã -60Ã .
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公开(公告)号：GB2520429B
公开(公告)日：2016-04-20
申请号：GB201419724
申请日：2014-11-05
Applicant: IBM , CROCUS TECHNOLOGY SA
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