Nondestructive investigation of interface states in high‐k oxide films on Ge substrate using X‐ray absorption spectroscopy |
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| Authors: | Deok‐Yong Cho Hyung‐Suk Jung Il‐Hyuk Yu Won Goo Park Suyeon Cho Useong Kim Se‐Jung Oh Byeong‐Gyu Park Fan‐Hsiu Chang Hong‐Ji Lin Cheol Seong Hwang |
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| Affiliation: | 1. IWE2 & JARA‐FIT, RWTH Aachen University, 52056 Aachen, Germany;2. WCU Hybrid Material Program, Department of Materials Science and Engineering and Inter‐University Semiconductor Research Center, Seoul National University, Seoul 151‐744, Korea;3. Department of Physics and Astronomy, Seoul National University, Seoul 151‐747, Korea;4. Pohang Light Source, Pohang University of Science and Technology, Pohang 790‐784, Korea;5. National Synchrotron Radiation Research Center, 30076 Hsinchu, Taiwan |
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| Abstract: | The unoccupied electronic structures of 5 nm thick high permittivity (k) oxides (HfO2, ZrO2, and Al2O3) and SiO2 films on Ge substrates were examined using O K‐edge X‐ray absorption spectroscopy. Comparative studies with those on Si substrates showed contrasts in the conduction bands, which should be due to the formation of interface states. In the Al2O3 and SiO2 films, GeO2 layers are formed at the interface and they suppress in part the formation of detrimental germanate phases. In contrast, in the HfO2 and ZrO2 films, no signature of the Ge‐oxide phase is observed but some germanate phases are expected to prevail, suggesting a degradation of the gate oxide characteristics. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) |
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| Keywords: | high‐k dielectrics oxides germanium X‐ray absorption spectroscopy |
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