Observation of Si 2p Core‐Level Shift in Si/High‐κ Dielectric Interfaces Containing a Negative Charge

: Lehtiö Juha-Pekka, Rad Zahra Jahanshah, Granroth Sari, Yasir Muhammad, Punkkinen Marko, Punkkinen Risto, Hedman Hannu-Pekka, Rueff Jean-Pascal, Rauha Ismo TS, Savin Hele, Laukkanen Pekka, Kokko Kalevi

Publisher: WILEY

: 2021

: Advanced Electronic Materials

: ADVANCED ELECTRONIC MATERIALS

: ADV ELECTRON MATER

: ARTN 2100034

: 7

: 4

: 6

: 2199-160X

DOI: https://doi.org/10.1002/aelm.202100034

: https://onlinelibrary.wiley.com/doi/full/10.1002/aelm.202100034

: https://research.utu.fi/converis/portal/detail/Publication/53647827

Negative static charge and induced internal electric field have often
been observed in the interfaces between silicon and high‐κ dielectrics,
for example Al₂O₃ and HfO₂. 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 SiO₂ 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 SiO₂.

aelm.202100034.pdf