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Observation of Si 2p Core‐Level Shift in Si/High‐κ Dielectric Interfaces Containing a Negative Charge
Author(s) -
Lehtiö JuhaPekka,
Rad Zahra Jahanshah,
Granroth Sari,
Yasir Muhammad,
Punkkinen Marko,
Punkkinen Risto,
Hedman HannuPekka,
Rueff JeanPascal,
Rauha Ismo T.S.,
Savin Hele,
Laukkanen Pekka,
Kokko Kalevi
Publication year - 2021
Publication title -
advanced electronic materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.25
H-Index - 56
ISSN - 2199-160X
DOI - 10.1002/aelm.202100034
Subject(s) - materials science , dielectric , electric field , passivation , charge (physics) , silicon , condensed matter physics , acceptor , core (optical fiber) , charge density , chemical physics , optoelectronics , nanotechnology , layer (electronics) , chemistry , composite material , physics , quantum mechanics
Negative static charge and induced internal electric field have often been observed in the interfaces between silicon and high‐κ dielectrics, for example Al 2 O 3 and HfO 2 . The electric field provides either beneficial (e.g., field‐effect passivation) or harmful (e.g., voltage instability) effect depending on the application. Different intrinsic and extrinsic defects in the dielectric film and interface have been suggested to cause the static charge but this issue is still unresolved. Here spectroscopic evidence is presented for a structural change in the interfaces where static charge is present. The observed correlation between the Si core‐level shift and static negative charge reveals the role of Si bonding environment modification in the SiO 2 phase. The result is in good agreement with recent theoretical models, which relate the static charge formation to interfacial atomic transformations together with the resulting acceptor doping of SiO 2 .