Nano-ring-type magnetic tunnel junctions (NR-MTJs) with the layer structure of Ta(5)/Ir22Mn78(10)/Co75Fe25(2)/Ru(0.75)/Co60Fe20B20(3)/Al(0.6)-oxide/Co60Fe20B20(2.5)/Ta(3)/Ru(5) (thickness unit: nm)were nano-fabricated on the Si(100)/SiO2 substrate using magnetron sputtering deposition combined with the optical lithography, electron beam lithography (EBL) and Ar ion-beam etching techniques. The smaller NR-MTJs with the inner- and outer-diameter of around 50 and 100 nm and also their corresponding NR-MTJ arrays were nano-patterned. The tunnelling magnetoresistance (TMR & R) versus driving current (I) loops for a spin-polarized current switching were measured, and the TMR ratio of around 35% at room temperature were observed. The critical values of switching current for the free Co60Fe20B20 layer relative to the reference Co60Fe20B20 layer between parallel and anti-parallel magnetization states were between 0.50 and 0.75 mA in such NR-MTJs. It is suggested that the applicable MRAM fabrication with the density and capacity higher than 256 Mbit/inch2 even 6 Gbite/inch2 are possible using both 1 NR-MTJ+1 transistor structure and current switching mechanism based on based on our fabricated 4×4 MRAM demo devices.
参考文献
| [1] | J C Slonczewski .[J].J Magn Magn Máter,1996,159:L1-L7. |
| [2] | S Zhang;P M Levy;A Fert .[J].Physical Review Letters,2002,88:236601. |
| [3] | X F Han;T Miyazaki .[J].Journal of Materials Science and Technology,2000,16:549. |
| [4] | Y Liu;Z Zhang;P P Freitas;J L Martins .[J].Applied Physics Letters,2003,82:2871. |
| [5] | X.F. Han;S.F. Zhao;Andrew C.C. Yu .Current-induced butterfly shaped domains and magnetization switching in magnetic tunnel junctions[J].Science and technology of advanced materials,2005(7):784-788. |
| [6] | Z Diao;D Apalkov;M Pakala;Y Ding,A Panchula and Y Huai .[J].Applied Physics Letters,2005,87:232502. |
| [7] | Y Wang;Z Y Lu;X G Zhang;X F Han .[J].Physical Review Letters,2006,97:87210. |
| [8] | F F Li;X F Han;L X Jiang;J Zhao,L Wang and R Sharif .[J].Journal of Materials Science and Technology,2005,21:289. |
| [9] | Z M Zeng;J F Feng;Y Wang;X F Han,W S Zhan,X G Zhang and Z Zhang .[J].Physical Review Letters,2006,97:106605. |
| [10] | F Q Zhu;G W Chern;O Tchernyshyov;X C Zhu,J G Zhu and C L Chien .[J].Physical Review Letters,2006,96:27205. |
| [11] | H X Wei;Q H Qin;M Ma;R Sharif and X F Han.[J].Journal of Applied Physics,2007 |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%