Oxygen vacancy formation and uniformity of conductive filaments in Si-doped Ta2O5 RRAM

Abstract

The physical mechanism of the effect of Si dopant on the formation of oxygen vacancy (VO) and the uniformity of conductive filaments (CFs) are explored in Ta2O5-based resistive random access memory (Ta2O5-RRAM). On the basis of first-principle calculations, we investigated the effect of Si dopant on the electronic structure of Ta2O5, including the formation energy of VO, Bader charge, density of states (DOS), and interaction of Si dopant with VO. Results of formation energy and Bader charge reveal that Si dopant is favorable to the formation of VO. Results of DOS reveal that Si dopant can improve the conductivity of Ta2O5. The interaction of Si dopant with VO can enhance the uniformity of CFs. Si dopant is favorable in reducing the formation energy of VO and improving the switching uniformity of Ta2O5-RRAM devices.