High magnetoresistance in Co–Fe–B-based double barrier magnetic tunnel junction

Controlled fabrication of nano-scale double barrier magnetic tunnel junctions using focused ion beam milling method

“…3. The same results were also observed by other researchers [10,14], which is likely due to subtle differences in the upper and lower metal/oxide interfaces corresponding at each AlOx barrier. It can be clearly seen that the voltage value for which the TMR decreases to half of its maximum value measured at low bias V 1/2 is about 1.06 V, which is almost two times that of the single barrier MTJs.…”

“…After annealing at 275 1C for an hour, the TMR ratio increased to 51%. This value agrees well with those fabricated by a traditional process [14]. The increase of the TMR ratio after annealing may be attributed to an improvement of the smoothness of the interface between the ferromagnetic/ insulator (FM/I) layers and barrier homogenization as the result of the reduction in the defect density in the Al-oxide barrier.…”

Fabrication of spintronic devices: etching endpoint detection by resistance measurement for magnetic tunnel junctions

“…We have repeated the same simulation with 20 nm Cu as the bottom conductive layer instead of Au. Cu is another commonly used bottom electrode in MTJs and it has a resistivity of 1.7x10 -8 ohm m which is even lower than Au [15]. Similar resistance and conductance vs etch depth graphs are obtained in Figures 4c and 4d.…”

Magnetoresistance and switching properties of magnetic tunnel junctions using amorphous CoSiB free layer

“…Such high value of V 1/2 is desirable for high performance MRAM [6]. An asymmetry of the bias voltage dependence is due to differences in two interfaces between the AlO x barrier layer and two ferromagnetic (top and bottom) electrodes [2,7].…”