1. Degradation mechanism of HfAlOX/SiO2 stacked gate dielectrics studied by transient and steady-state leakage current analysis.
- Author
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Okada, Kenji, Mizubayashi, Wataru, Yasuda, Naoki, Ota, Hiroyuki, Tominaga, Koji, Iwamoto, Kunihiko, Horikawa, Tsuyoshi, Yamamoto, Katsuhiko, Hisamatsu, Hirokazu, Satake, Hideki, Nabatame, Toshihide, and Toriumi, Akira
- Subjects
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DIELECTRICS , *EXCITON theory , *SEMICONDUCTORS , *CAPACITORS , *LOW voltage systems , *ELECTRIC currents - Abstract
Degradation mechanism of stacked high-k gate dielectrics has been studied with metal-oxide-semiconductor capacitors having HfAlOX/SiO2 films of various thickness combinations. A large leakage current with a peaked shape, named as the low-voltage peak current (LVPC), has been observed in the low-voltage region even in the initial current–voltage characteristics. It has been shown that a main part of LVPC is the transient current component controlled by the process of hole injection to traps in the vicinity of the HfAlOX/SiO2 interface through the interfacial SiO2 layer. By the electrical stress, both the transient and the steady-state current components monotonically increase with time having different rates. Steady-state component has significantly larger rate than the transient component, and the same rate with the stress-induced leakage current (SILC) observed in the high-voltage region, indicating that the steady-state component of LVPC should be regarded as the SILC in the higher-voltage region extending down to the lower gate voltage region where the LVPC is observed. [ABSTRACT FROM AUTHOR]
- Published
- 2005
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