https://doi.org/10.1051/epjap:2007129
The conduction band alignment of HfO2 caused by oxygen vacancies and its effects on the gate leakage current in MOS structures
1
School of Electronics & Information Engineering, Soochow University, 178 Gan-jiang East Road, Suzhou 215021, P.R. China
2
Institute of Microelectronics Peking University, Beijing 100871,
P.R. China
Corresponding author: mail_lingfeng@yahoo.com.cn
Received:
2
May
2007
Accepted:
9
July
2007
Published online:
31
August
2007
Based on the first-principles simulations, the oxygen vacancies in the ultrathin HfO2 layer as the gate dielectric in a metal-oxide-semiconductor structure is found to result in the conduction band offset alignment around the vacancy. Thus an increase in the gate leakage current tunneling current comes when the oxygen vacancies appear in the HfO2 layer wherever the oxygen vacancies locate. The relative increase in the tunneling current caused by the oxygen vacancies slightly change with the increasing oxide thickness for a low oxide electric field.
PACS: 73.40.Gk – Tunneling / 73.40.Qv – Metal-insulator-semiconductor structures / 74.50.+r – Tunneling phenomena; point contacts, weak links, Josephson effects
© EDP Sciences, 2007
