Evolution of barrier-resistance noise in CoFeB/MgO/CoFeB tunnel junctions during annealing

Ryan Stearrett, Weigang Wang, L. R. Shah, Aisha Gokce, J. Q. Xiao, E. R. Nowak

Research output: Contribution to journalArticle

27 Citations (Scopus)

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 languageEnglish (US)
Article number064502
JournalJournal of Applied Physics
Volume107
Issue number6
DOIs
StatePublished - 2010
Externally publishedYes

Fingerprint

tunnel junctions
annealing
temperature
low frequencies
defects
electric potential

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 journalArticle

Stearrett, Ryan ; Wang, Weigang ; Shah, L. R. ; Gokce, Aisha ; Xiao, J. Q. ; Nowak, E. R. / Evolution of barrier-resistance noise in CoFeB/MgO/CoFeB tunnel junctions during annealing. In: Journal of Applied Physics. 2010 ; Vol. 107, No. 6.
@article{e3d985133cbc4fc79f94280bc82e34c5,
title = "Evolution of barrier-resistance noise in CoFeB/MgO/CoFeB tunnel junctions during annealing",
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.",
author = "Ryan Stearrett and Weigang Wang and Shah, {L. R.} and Aisha Gokce and Xiao, {J. Q.} and Nowak, {E. R.}",
year = "2010",
doi = "10.1063/1.3327440",
language = "English (US)",
volume = "107",
journal = "Journal of Applied Physics",
issn = "0021-8979",
publisher = "American Institute of Physics Publising LLC",
number = "6",

}

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 -