X-ray absorption spectroscopy studies on magnetic tunnel junctions with AlO and AlN tunnel barriers

B. S. Mun, J. C. Moon, S. W. Hong, K. S. Kang, K. Kim, T. W. Kim, H. L. Ju

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

X-ray photoelectron spectroscopy (XPS) and x-ray absorption spectroscopy (XAS) measurements of the optimized magnetic tunnel junctions (MTJs) with AlO and AlN barriers have been performed to study the chemical structures of the barrier and the underlying layer. These MTJs with AlO and AlN barriers exhibited increased tunneling magnetoresistance (TMR) after annealing at 200 °C from 27% to 45% and from 25% to 33%, respectively. Surprisingly, the XPS and XAS measurements confirmed that both the as-grown and the annealed MTJs had metallic Co and Fe at the interface between the barrier and the underlying CoFe layer. After annealing, under-stoichiometric AlOx and AlNx phases in MTJs with AlO and AlN barriers partially transformed into stoichiometric Al2 O3 and AlN phases, respectively. Thus the increase in TMR after annealing for MTJs with clean interface between the barrier and the underlying layer is believed due to the anion redistribution inside the barrier layer, not from back diffusion from pinned magnetic layer to barrier layer.

Original languageEnglish
Article number08E506
JournalJournal of Applied Physics
Volume99
Issue number8
DOIs
Publication statusPublished - 2006 May 25

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tunnel junctions
tunnels
absorption spectroscopy
x rays
barrier layers
x ray absorption
x ray spectroscopy
annealing
photoelectron spectroscopy
anions

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Mun, B. S. ; Moon, J. C. ; Hong, S. W. ; Kang, K. S. ; Kim, K. ; Kim, T. W. ; Ju, H. L. / X-ray absorption spectroscopy studies on magnetic tunnel junctions with AlO and AlN tunnel barriers. In: Journal of Applied Physics. 2006 ; Vol. 99, No. 8.
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X-ray absorption spectroscopy studies on magnetic tunnel junctions with AlO and AlN tunnel barriers. / Mun, B. S.; Moon, J. C.; Hong, S. W.; Kang, K. S.; Kim, K.; Kim, T. W.; Ju, H. L.

In: Journal of Applied Physics, Vol. 99, No. 8, 08E506, 25.05.2006.

Research output: Contribution to journalArticle

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