发明名称 |
Magnetic tunnel junction for MRAM applications |
摘要 |
A MTJ in an MRAM array is disclosed with a composite free layer having a lower crystalline layer contacting a tunnel barrier and an upper amorphous NiFeX layer for improved bit switching performance. The crystalline layer is Fe, Ni, or FEB with a thickness of at least 6 Angstroms which affords a high magnetoresistive ratio. The X element in the NiFeX layer is Mg, Hf, Zr, Nb, or Ta with a content of 5 to 30 atomic % NiFeX thickness is preferably between 20 to 40 Angstroms to substantially reduce bit line switching current and number of shorted bits. In an alternative embodiments, the crystalline layer may be a Fe/NiFe bilayer. Optionally, the amorphous layer may have a NiFeM1/NiFeM2 configuration where M1 and M2 are Mg, Hf, Zr, Nb, or Ta, and M1 is unequal to M2. Annealing at 300° C. to 360° C. provides a high magnetoresistive ratio of about 150%. |
申请公布号 |
US8786036(B2) |
申请公布日期 |
2014.07.22 |
申请号 |
US201112930877 |
申请日期 |
2011.01.19 |
申请人 |
Headway Technologies, Inc. |
发明人 |
Cao Wei;Horng Cheng T.;Kula Witold;Torng Chyu Jiuh |
分类号 |
H01L43/10;H01L27/22 |
主分类号 |
H01L43/10 |
代理机构 |
Saile Ackerman LLC |
代理人 |
Saile Ackerman LLC ;Ackerman Stephen B. |
主权项 |
1. A MTJ element in a magnetic device, comprising:
at least a pinned layer/tunnel barrier layer/free layer configuration wherein the tunnel barrier layer has a first interface with the pinned layer, and the free layer is a composite comprised of a crystalline magnetic layer that is Fe, Ni, or FeB which interfaces with the tunnel barrier layer, and an amorphous NiFeX layer where X is one of Hf, Zr, Nb, Ta, or Mg, said amorphous NiFeX layer contacts a side of the crystalline magnetic layer that is opposite the interface with the tunnel barrier layer. |
地址 |
Milpitas CA US |