Spin Transfer Torque Magnetoresistive Random Access Memory
99
144. R. Meservey, P. Tedrow, Spin-polarized electron tunneling. Phys. Rep. 238, 173–243 (1994)
145. P. Tedrow, R. Meservey, Spin polarization of electrons tunneling from films of Fe Co, Ni, and
Gd. Phys. Rev. B 7, 318 (1973)
146. O. Se Young, C.-G. Lee, A.J. Shapiro, W.F. Egelhoff Jr., M.D. Vaudin, J.L. Ruglovsky, et al.,
“X-ray diffraction study of the optimization of MgO growth conditions for magnetic tunnel
junctions. J. Appl. Phys. 103, 07A920 (2008)
147. S. Yuasa, Y. Suzuki, T. Katayama, K. Ando, Characterization of growth and crystallization
processes in CoFeB/ MgO/ CoFeB magnetic tunnel junction structure by reflective highenergy electron diffraction. Appl. Phys. Lett. 87, 242503 (2005)
148. J. Hayakawa, S. Ikeda, F. Matsukura, H. Takahashi, H. Ohno, Dependence of giant tunnel
magnetoresistance of sputtered CoFeB/MgO/CoFeB magnetic tunnel junctions on MgO
barrier thickness and annealing temperature. Jpn. J. Appl. Phys. 44, L587 (2005)
149. T. Devolder, P.-H. Ducrot, J.-P. Adam, I. Barisic, N. Vernier, J.-V. Kim et al., Damping of
CoxFe80−xB20 ultrathin films with perpendicular magnetic anisotropy. Appl. Phys. Lett.
102, 022407 (2013)
150. M.P.R. Sabino, S. Ter Lim, M. Tran, Influence of Ta insertions on the magnetic properties of
MgO/CoFeB/MgO films probed by ferromagnetic resonance. Appl. Phys. Express 7, 093002
(2014)
151. G. Jan, Y.-J. Wang, T. Moriyama, Y.-J. Lee, M. Lin, T. Zhong et al., High spin torque efficiency
of magnetic tunnel junctions with MgO/CoFeB/MgO free layer. Appl. Phys. Express 5, 093008
(2012)
152. C. Bilzer, T. Devolder, J.-V. Kim, G. Counil, C. Chappert, S. Cardoso et al., Study of the
dynamic magnetic properties of soft CoFeB films. J. Appl. Phys. 100, 053903 (2006)
153. X. Liu, W. Zhang, M.J. Carter, G. Xiao, Ferromagnetic resonance and damping properties of
CoFeB thin films as free layers in MgO-based magnetic tunnel junctions. J. Appl. Phys. 110,
033910 (2011)
154. E.C.I. Enobio, H. Sato, S. Fukami, F. Matsukura, H. Ohno, CoFeB thickness dependence of
damping constants for single and double CoFeB-MgO interface structures. IEEE Magn. Lett.
6, 1–3 (2015)
155. C. Park, J.-G. Zhu, M.T. Moneck, Y. Peng, D.E. Laughlin, Annealing effects on structural and
transport properties of rf-sputtered CoFeB/MgO/CoFeB magnetic tunnel junctions. J. Appl.
Phys. 99, 08A901 (2006)
156. J. Swerts, S. Mertens, T. Lin, S. Couet, Y. Tomczak, K. Sankaran et al., BEOL compatible
high tunnel magneto resistance perpendicular magnetic tunnel junctions using a sacrificial
Mg layer as CoFeB free layer cap. Appl. Phys. Lett. 106, 262407 (2015)
157. X. Kozina, S. Ouardi, B. Balke, G. Stryganyuk, G.H. Fecher, C. Felser et al., A nondestructive
analysis of the B diffusion in Ta–CoFeB–MgO–CoFeB–Ta magnetic tunnel junctions by hard
x-ray photoemission. Appl. Phys. Lett. 96, 072105 (2010)
158. N. Miyakawa, D. Worledge, K. Kita, Impact of Ta diffusion on the perpendicular magnetic
anisotropy of Ta/CoFeB/MgO. IEEE Magn. Lett. 4, 1000104–1000104 (2013)
159. T. Miyajima, T. Ibusuki, S. Umehara, M. Sato, S. Eguchi, M. Tsukada et al., Transmission electron microscopy study on the crystallization and boron distribution of CoFeB/MgO/CoFeB
magnetic tunnel junctions with various capping layers. Appl. Phys. Lett. 94, 122501 (2009)
160. J.-H. Kim, J.-B. Lee, G.-G. An, S.-M. Yang, W.-S. Chung, H.-S. Park et al., Ultrathin W space
layer-enabled thermal stability enhancement in a perpendicular MgO/CoFeB/W/CoFeB/MgO
recording frame. Sci. Rep. 5, 16903 (2015)
161. S. Couet, J. Swerts, S. Mertens, T. Lin, Y. Tomczak, E. Liu et al., Oxygen scavenging by ta
spacers in double-MgO free layers for perpendicular spin-transfer torque magnetic randomaccess memory. IEEE Magn. Lett. 7, 3103004 (2016)
162. A. Le Goff, R. Soucaille, T. Tahmasebi, J. Swerts, A. Furnemont, T. Devolder, Optimization
of top-pinned perpendicular anisotropy tunnel junctions through Ta insertion. Jpn. J. Appl.
Phys. 54, 090302 (2015)
163. M.P.R. Sabino, T.L. Sze, M. Tran, Influence of Ta insertions on the magnetic properties of
MgO/CoFeB/MgO films probed by ferromagnetic resonance. Appl. Phys. Express 7, 093002
(2014)
99
144. R. Meservey, P. Tedrow, Spin-polarized electron tunneling. Phys. Rep. 238, 173–243 (1994)
145. P. Tedrow, R. Meservey, Spin polarization of electrons tunneling from films of Fe Co, Ni, and
Gd. Phys. Rev. B 7, 318 (1973)
146. O. Se Young, C.-G. Lee, A.J. Shapiro, W.F. Egelhoff Jr., M.D. Vaudin, J.L. Ruglovsky, et al.,
“X-ray diffraction study of the optimization of MgO growth conditions for magnetic tunnel
junctions. J. Appl. Phys. 103, 07A920 (2008)
147. S. Yuasa, Y. Suzuki, T. Katayama, K. Ando, Characterization of growth and crystallization
processes in CoFeB/ MgO/ CoFeB magnetic tunnel junction structure by reflective highenergy electron diffraction. Appl. Phys. Lett. 87, 242503 (2005)
148. J. Hayakawa, S. Ikeda, F. Matsukura, H. Takahashi, H. Ohno, Dependence of giant tunnel
magnetoresistance of sputtered CoFeB/MgO/CoFeB magnetic tunnel junctions on MgO
barrier thickness and annealing temperature. Jpn. J. Appl. Phys. 44, L587 (2005)
149. T. Devolder, P.-H. Ducrot, J.-P. Adam, I. Barisic, N. Vernier, J.-V. Kim et al., Damping of
CoxFe80−xB20 ultrathin films with perpendicular magnetic anisotropy. Appl. Phys. Lett.
102, 022407 (2013)
150. M.P.R. Sabino, S. Ter Lim, M. Tran, Influence of Ta insertions on the magnetic properties of
MgO/CoFeB/MgO films probed by ferromagnetic resonance. Appl. Phys. Express 7, 093002
(2014)
151. G. Jan, Y.-J. Wang, T. Moriyama, Y.-J. Lee, M. Lin, T. Zhong et al., High spin torque efficiency
of magnetic tunnel junctions with MgO/CoFeB/MgO free layer. Appl. Phys. Express 5, 093008
(2012)
152. C. Bilzer, T. Devolder, J.-V. Kim, G. Counil, C. Chappert, S. Cardoso et al., Study of the
dynamic magnetic properties of soft CoFeB films. J. Appl. Phys. 100, 053903 (2006)
153. X. Liu, W. Zhang, M.J. Carter, G. Xiao, Ferromagnetic resonance and damping properties of
CoFeB thin films as free layers in MgO-based magnetic tunnel junctions. J. Appl. Phys. 110,
033910 (2011)
154. E.C.I. Enobio, H. Sato, S. Fukami, F. Matsukura, H. Ohno, CoFeB thickness dependence of
damping constants for single and double CoFeB-MgO interface structures. IEEE Magn. Lett.
6, 1–3 (2015)
155. C. Park, J.-G. Zhu, M.T. Moneck, Y. Peng, D.E. Laughlin, Annealing effects on structural and
transport properties of rf-sputtered CoFeB/MgO/CoFeB magnetic tunnel junctions. J. Appl.
Phys. 99, 08A901 (2006)
156. J. Swerts, S. Mertens, T. Lin, S. Couet, Y. Tomczak, K. Sankaran et al., BEOL compatible
high tunnel magneto resistance perpendicular magnetic tunnel junctions using a sacrificial
Mg layer as CoFeB free layer cap. Appl. Phys. Lett. 106, 262407 (2015)
157. X. Kozina, S. Ouardi, B. Balke, G. Stryganyuk, G.H. Fecher, C. Felser et al., A nondestructive
analysis of the B diffusion in Ta–CoFeB–MgO–CoFeB–Ta magnetic tunnel junctions by hard
x-ray photoemission. Appl. Phys. Lett. 96, 072105 (2010)
158. N. Miyakawa, D. Worledge, K. Kita, Impact of Ta diffusion on the perpendicular magnetic
anisotropy of Ta/CoFeB/MgO. IEEE Magn. Lett. 4, 1000104–1000104 (2013)
159. T. Miyajima, T. Ibusuki, S. Umehara, M. Sato, S. Eguchi, M. Tsukada et al., Transmission electron microscopy study on the crystallization and boron distribution of CoFeB/MgO/CoFeB
magnetic tunnel junctions with various capping layers. Appl. Phys. Lett. 94, 122501 (2009)
160. J.-H. Kim, J.-B. Lee, G.-G. An, S.-M. Yang, W.-S. Chung, H.-S. Park et al., Ultrathin W space
layer-enabled thermal stability enhancement in a perpendicular MgO/CoFeB/W/CoFeB/MgO
recording frame. Sci. Rep. 5, 16903 (2015)
161. S. Couet, J. Swerts, S. Mertens, T. Lin, Y. Tomczak, E. Liu et al., Oxygen scavenging by ta
spacers in double-MgO free layers for perpendicular spin-transfer torque magnetic randomaccess memory. IEEE Magn. Lett. 7, 3103004 (2016)
162. A. Le Goff, R. Soucaille, T. Tahmasebi, J. Swerts, A. Furnemont, T. Devolder, Optimization
of top-pinned perpendicular anisotropy tunnel junctions through Ta insertion. Jpn. J. Appl.
Phys. 54, 090302 (2015)
163. M.P.R. Sabino, T.L. Sze, M. Tran, Influence of Ta insertions on the magnetic properties of
MgO/CoFeB/MgO films probed by ferromagnetic resonance. Appl. Phys. Express 7, 093002
(2014)