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Molecular-dynamics study of interfacial diffusion between high-permittivity gate dielectrics and germanium substrates

Published online by Cambridge University Press:  03 March 2011

T. Iwasaki
T. Iwasaki*
Affiliation:
Mechanical Engineering Research Laboratory, Hitachi, Ltd., Hitachinaka, Ibaraki 312-0034, Japan
*
a)Address all correspondence to this author. e-mail: tomio.iwasaki.rj@hitachi.com
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Abstract

The stability of interfaces with germanium, which has recently been discussed as a replacement for silicon in ultra-large-scale integrated circuits (ULSIs), was studied. Interfacial oxygen diffusion from high-permittivity gate dielectrics (ZrO2 and HfO2) into germanium substrates must be suppressed to prevent the formation of interfacial layers between the gate dielectrics and the germanium substrates. Oxygen diffusion was simulated through a molecular-dynamics technique that takes into account many-body interactions and charge transfer between different elements. The simulation results show that the addition of yttrium is effective in suppressing interfacial oxygen diffusion at the ZrO2/germanium interfaces. On the other hand, the addition of yttrium is not effective in suppressing interfacial oxygen diffusion at the HfO2/germanium interfaces. The results also show that the diffusion at the ZrO2/Ge(111) and HfO2/Ge(111) interfaces is much more suppressed than the diffusion at the ZrO2/Ge(001) and HfO2/Ge(001) interfaces.

Keywords

DiffusionMicroelectronicsSemiconductor
Type
Articles
Information
Journal of Materials Research , Volume 20 , Issue 5 , May 2005 , pp. 1300 - 1307
Copyright
Copyright © Materials Research Society 2005

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