TY - GEN
T1 - Degradation of reliability of high-k gate dielectrics caused by point defects and residual stress
AU - Miura, Hideo
AU - Suzuki, Ken
AU - Ikoma, Toru
AU - Samukawa, Seiji
AU - Yoshikawa, Hideki
AU - Ueda, Shigenori
AU - Yamashita, Yoshiyuki
AU - Kobayashi, Keisuke
PY - 2008
Y1 - 2008
N2 - In this study, the degradation mechanism of dielectric properties of hafnium dioxide thin films was investigated by using quantum chemical molecular dynamics. Effects of point defects such as oxygen vacancies and carbon interstitials and residual stress in the films on their local band gap were analyzed quantitatively. Drastic decrease of the local band gap from about 5.7 eV to about 1.0 eV was caused by the formation of a defect-induced site in the band gap. Though this defect-induced site was recovered by additional oxidation, the remaining interstitial oxygen deteriorated the quality of the interface with tungsten electrode by forming new oxide between them. The estimated changes of the band gap and the interface structure were confirmed by experiments using synchrotron-radiation photoemission spectroscopy.
AB - In this study, the degradation mechanism of dielectric properties of hafnium dioxide thin films was investigated by using quantum chemical molecular dynamics. Effects of point defects such as oxygen vacancies and carbon interstitials and residual stress in the films on their local band gap were analyzed quantitatively. Drastic decrease of the local band gap from about 5.7 eV to about 1.0 eV was caused by the formation of a defect-induced site in the band gap. Though this defect-induced site was recovered by additional oxidation, the remaining interstitial oxygen deteriorated the quality of the interface with tungsten electrode by forming new oxide between them. The estimated changes of the band gap and the interface structure were confirmed by experiments using synchrotron-radiation photoemission spectroscopy.
KW - Band gap
KW - Hafnium oxide
KW - High-k gate dielectrics
KW - Point defects
KW - Quantum chemical molecular dynamics
KW - Residual stress
KW - Synchrotron-radiation photoemission spectroscopy
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U2 - 10.1109/RELPHY.2008.4559002
DO - 10.1109/RELPHY.2008.4559002
M3 - Conference contribution
AN - SCOPUS:51549102625
SN - 9781424420506
T3 - IEEE International Reliability Physics Symposium Proceedings
SP - 713
EP - 714
BT - 46th Annual 2008 IEEE International Reliability Physics Symposium Proceedings, IRPS
T2 - 46th Annual 2008 IEEE International Reliability Physics Symposium, IRPS
Y2 - 27 April 2008 through 1 May 2008
ER -