TY - JOUR
T1 - Radical nitridation of Al films for the barrier formation in ferromagnetic tunnel junctions
AU - Tsunoda, Masakiyo
AU - Shoyama, Toshihiro
AU - Yoshimura, Satoru
AU - Takahashi, Migaku
N1 - Funding Information:
This study was supported by the IT-program of Research Revolution 2002 (RR2002) “Development of Universal Low-Power Spin Memory” from the Ministry of Education, Culture, Sports, Science and Technology of Japan.
PY - 2005/2
Y1 - 2005/2
N2 - Nitridation process of Al films using microwave-excited plasma was investigated to realize highly qualified Al-N barrier for magnetic tunnel junctions (MTJs), in comparison with reactive deposition process of Al-N films. The MTJs fabricated by the plasma nitridation method with Kr+N 2 or Ar+N 2 mixed gas showed larger values of tunnel magnetoresistance (TMR) ratio and resistance-area product (R×A) than those of the MTJs fabricated with He+N 2 plasma. The MTJs with reactive-deposited Al-N showed relatively small values of TMR ratio and R×A. From the optical emission spectroscopy of the respective plasma, we concluded that N 2 ion in the plasma is a responsible factor for lowering the barrier height of Al-N and that radical nitridation process is suitable to form the barriers without inducing defects.
AB - Nitridation process of Al films using microwave-excited plasma was investigated to realize highly qualified Al-N barrier for magnetic tunnel junctions (MTJs), in comparison with reactive deposition process of Al-N films. The MTJs fabricated by the plasma nitridation method with Kr+N 2 or Ar+N 2 mixed gas showed larger values of tunnel magnetoresistance (TMR) ratio and resistance-area product (R×A) than those of the MTJs fabricated with He+N 2 plasma. The MTJs with reactive-deposited Al-N showed relatively small values of TMR ratio and R×A. From the optical emission spectroscopy of the respective plasma, we concluded that N 2 ion in the plasma is a responsible factor for lowering the barrier height of Al-N and that radical nitridation process is suitable to form the barriers without inducing defects.
KW - Al-N
KW - Barrier formation
KW - Magnetic tunnel junction
KW - Nitridation
KW - Tunnel magnetoresistance
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U2 - 10.1016/j.jmmm.2004.10.098
DO - 10.1016/j.jmmm.2004.10.098
M3 - Article
AN - SCOPUS:11444258119
SN - 0304-8853
VL - 286
SP - 162
EP - 166
JO - Journal of Magnetism and Magnetic Materials
JF - Journal of Magnetism and Magnetic Materials
IS - SPEC. ISS.
ER -