Oxygen-vacancy-induced threshold voltage shifts in Hf-related high-k gate stacks
| Autor: | Tsunetoshi Arikado, Kenji Shiraishi, Kazuyoshi Torii, Yasushi Akasaka, Kiyomi Nakajima, Keisaku Yamada, Toyohiro Chikyow, Hiroshi Kitajima, Mitsuru Konno, Yasuo Nara |
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| Rok vydání: | 2006 |
| Předmět: |
Condensed matter physics
Band gap Chemistry Fermi level Metals and Alloys Ionic bonding Surfaces and Interfaces Oxygen vacancy Surfaces Coatings and Films Electronic Optical and Magnetic Materials Threshold voltage symbols.namesake Electron transfer Materials Chemistry symbols Field-effect transistor High-κ dielectric |
| Zdroj: | Thin Solid Films. 508:305-310 |
| ISSN: | 0040-6090 |
| Popis: | We have investigated theoretically the cause of the substantial threshold voltage (Vth) shifts observed in Hf-related high-k gate stacks with p+poly-Si gates, by focusing on the ionic nature of HfO2. The oxygen vacancy (Vo) level in ionic HfO2 is located in a relatively higher part of the band gap. This high position of the Vo level results in a significant elevation of the Fermi level for p+poly-Si gates, if the p+poly-Si gate is in contact with the high-k HfO2. Vo formation in the HfO2 induces a subsequent electron transfer across the interface, causing a substantial Vth shifts in p+poly-Si gate MISFETs. Moreover, our theory also systematically reproduces other recent experimental results. |
| Databáze: | OpenAIRE |
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