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Nano Research

Article Title

Dynamic observation of oxygen vacancies in hafnia layer by in situ transmission electron microscopy

Keywords

charge-trapping flash, in situ TEM, electric field, oxygen vacancy

Abstract

The charge-trapping process, with HfO2 film as the charge-capturing layer, has been investigated by using in situ electron energy-loss spectroscopy and in situ energy-filter image under positive external bias. The results show that oxygen vacancies are non-uniformly distributed throughout the HfO2 trapping layer during the programming process. The distribution of the oxygen vacancies is not the same as that of the reported locations of the trapped electrons, implying that the trapping process is more complex. These bias-induced oxygen defects may affect the device performance characteristics such as the device lifetime. This phenomenon should be considered in the models of trapping processes.

Graphical Abstract

Publisher

Tsinghua University Press

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