TY - JOUR
T1 - Effect of diffused b during annealing on the electronic structure of the MgO barrier in CoFeB/MgO/CoFeB magnetic tunnel junctions
AU - Han, Yoonsung
AU - Han, Jinhee
AU - Choi, Hyoung Joon
AU - Shin, Hyun Joon
AU - Hong, Jongill
PY - 2012/3
Y1 - 2012/3
N2 - We investigate the chemical state and electronic structure of boron in the MgO layer in CoFeB/MgO/CoFeB magnetic tunnel junctions by synchrotron radiation X-ray photoelectron spectroscopy and first-principles calculations. In the top CoFeB, we observe three boron 1s peaks corresponding to oxidic, intermediate, and metallic boron. As the annealed films were etched, the B 2O 3 starts to appear together with the Mg 2p peak, indicating that boron atoms diffuse into the MgO barrier. Our calculations show that B impurities in the MgO barrier do not create any midgap states but reduce the MgO barrier height with the increase of boron concentration.
AB - We investigate the chemical state and electronic structure of boron in the MgO layer in CoFeB/MgO/CoFeB magnetic tunnel junctions by synchrotron radiation X-ray photoelectron spectroscopy and first-principles calculations. In the top CoFeB, we observe three boron 1s peaks corresponding to oxidic, intermediate, and metallic boron. As the annealed films were etched, the B 2O 3 starts to appear together with the Mg 2p peak, indicating that boron atoms diffuse into the MgO barrier. Our calculations show that B impurities in the MgO barrier do not create any midgap states but reduce the MgO barrier height with the increase of boron concentration.
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U2 - 10.1143/APEX.5.033001
DO - 10.1143/APEX.5.033001
M3 - Article
AN - SCOPUS:84863397217
SN - 1882-0778
VL - 5
JO - Applied Physics Express
JF - Applied Physics Express
IS - 3
M1 - 033001
ER -