Abstract
The low-frequency resistance noise in sputtered-deposited magnetic tunnel junctions with MgO barriers has been measured as a function of annealing time at different annealing temperatures. The noise has a 1/f spectrum and it is quantified by a Hooge-like parameter α given in units of μ m 2. Unannealed devices have the highest noise levels and their α parameters exhibit a pronounced dependence on the voltage bias across the junction. A significant increase in tunneling magnetoresistance (TMR) is observed for short annealing times (on the order of minutes) at high temperatures and it is correlated with a large reduction in noise and in its bias dependence. The maximum TMR and minimum noise levels are reached at a later time that depends on temperature, being shorter at higher annealing temperatures. Devices annealed at 380 and at 430 °C exhibit the same minimum noise levels, α≈2× 10-10 μ m2. The origin of the resistance noise, its annealing time evolution, and its bias dependence are discussed and they are attributed to vacancy defects in the MgO barriers.
| Original language | English (US) |
|---|---|
| Article number | 064502 |
| Journal | Journal of Applied Physics |
| Volume | 107 |
| Issue number | 6 |
| DOIs | |
| State | Published - 2010 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Physics and Astronomy(all)
Cite this
Evolution of barrier-resistance noise in CoFeB/MgO/CoFeB tunnel junctions during annealing. / Stearrett, Ryan; Wang, Weigang; Shah, L. R.; Gokce, Aisha; Xiao, J. Q.; Nowak, E. R.
In: Journal of Applied Physics, Vol. 107, No. 6, 064502, 2010.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Evolution of barrier-resistance noise in CoFeB/MgO/CoFeB tunnel junctions during annealing
AU - Stearrett, Ryan
AU - Wang, Weigang
AU - Shah, L. R.
AU - Gokce, Aisha
AU - Xiao, J. Q.
AU - Nowak, E. R.
PY - 2010
Y1 - 2010
N2 - The low-frequency resistance noise in sputtered-deposited magnetic tunnel junctions with MgO barriers has been measured as a function of annealing time at different annealing temperatures. The noise has a 1/f spectrum and it is quantified by a Hooge-like parameter α given in units of μ m 2. Unannealed devices have the highest noise levels and their α parameters exhibit a pronounced dependence on the voltage bias across the junction. A significant increase in tunneling magnetoresistance (TMR) is observed for short annealing times (on the order of minutes) at high temperatures and it is correlated with a large reduction in noise and in its bias dependence. The maximum TMR and minimum noise levels are reached at a later time that depends on temperature, being shorter at higher annealing temperatures. Devices annealed at 380 and at 430 °C exhibit the same minimum noise levels, α≈2× 10-10 μ m2. The origin of the resistance noise, its annealing time evolution, and its bias dependence are discussed and they are attributed to vacancy defects in the MgO barriers.
AB - The low-frequency resistance noise in sputtered-deposited magnetic tunnel junctions with MgO barriers has been measured as a function of annealing time at different annealing temperatures. The noise has a 1/f spectrum and it is quantified by a Hooge-like parameter α given in units of μ m 2. Unannealed devices have the highest noise levels and their α parameters exhibit a pronounced dependence on the voltage bias across the junction. A significant increase in tunneling magnetoresistance (TMR) is observed for short annealing times (on the order of minutes) at high temperatures and it is correlated with a large reduction in noise and in its bias dependence. The maximum TMR and minimum noise levels are reached at a later time that depends on temperature, being shorter at higher annealing temperatures. Devices annealed at 380 and at 430 °C exhibit the same minimum noise levels, α≈2× 10-10 μ m2. The origin of the resistance noise, its annealing time evolution, and its bias dependence are discussed and they are attributed to vacancy defects in the MgO barriers.
UR - http://www.scopus.com/inward/record.url?scp=77950552920&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77950552920&partnerID=8YFLogxK
U2 - 10.1063/1.3327440
DO - 10.1063/1.3327440
M3 - Article
AN - SCOPUS:77950552920
VL - 107
JO - Journal of Applied Physics
JF - Journal of Applied Physics
SN - 0021-8979
IS - 6
M1 - 064502
ER -