Electrical characteristics and conduction mechanisms of amorphous subnanometric Al 2 O 3 –TiO 2 laminate dielectrics deposited by atomic layer deposition

Electric conduction mechanisms of amorphous Al2O3/TiO2(ATO)-laminates deposited by atomiclayer deposition with sub-nanometer individual layer thicknesses were studied in a large temperaturerange. Two characteristic field regions are identified. In the low field region (E0.31 MV/cm), theleakage curre...

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Bibliographic Details
Published in:Applied physics letters 2016-11, Vol.109 (20)
Main Authors: Kahouli, Abdelkader, Lebedev, Oleg, Dao, Vu Hung, Elbahri, Marwa Ben, Prellier, Wilfrid, Luders, Ulrike
Format: Article
Language:English
Subjects:
Chemical Sciences
Material chemistry
Physics
Online Access:Get full text
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Summary:Electric conduction mechanisms of amorphous Al2O3/TiO2(ATO)-laminates deposited by atomiclayer deposition with sub-nanometer individual layer thicknesses were studied in a large temperaturerange. Two characteristic field regions are identified. In the low field region (E0.31 MV/cm), theleakage current is dominated by the trap-assisted tunneling through oxygen vacancies occurring in theTiO2, while in the high electric field region (E>0.31 MV/cm) the Poole Frenkel (PF) hopping is theappropriate conduction process with energy levels depending on the temperature and the electric field.It is shown that the PF potential levels decrease with the applied ATO field due to the overlapping ofthe Coulomb potential. Amorphous ATO-laminates show the presence of two intrinsic potentialenergy levels/i, which are 0.18 eV for low temperature region and 0.4 eV at high temperature region.Oxygen vacancies are the main origin of traps, which is consistent with the principal mechanisms forleakage in ATO-laminates.
ISSN:0003-6951
1077-3118
DOI:10.1063/1.4967534