Interface defect-assisted single electron charging (and discharging)
dynamics in Ge nanocrystals memories
APPLIED PHYSICS LETTERS, (2010)DOI: 10.1063/1.3455899
Zusammenfassung
The charging and discharging dynamics of Ge nanocrystal memories is
measured and compared with a realistic quantum mechanical model that is
able to reproduce qualitatively the overall device behavior.
Quantitatively, the charging (discharging) dynamics is faster (slower)
than predicted by calculations. To explain the discrepancies, we propose
the quantum confined nanocrystal states are responsible for collecting
the incoming electrons, but some of them are captured by defects in the
nanocrystal surface. The potential created by the filled defects modify
the spatial distribution of the nanocrystal wave functions, enhancing
their penetration in the tunneling oxide and increasing the incoming
transition rates. In the discharging process, the electrons confined in
the nanocrystal states escape initially, while the ones in the defects
have to be thermally excited to the nanocrystals states in order to
tunnel out, slowing down the escape of the last few electrons. (c) 2010
American Institute of Physics. doi: 10.1063/1.3455899