Origin of leakage paths driven by electric fields in Al-doped TiO2 films

Abstract

The growth of leakage current paths in Al-doped TiO2 (ATO) films is observed by in situ TEM under negative bias stress. Through systematic HAADF-STEM, STEM-EDS, and STEM-EELS studies, it is confirmed that the electric field-induced growth of the Ru-doped TiO2 phase is the main reason for the ATO film's negative leakage.

Keywords: Al-doped TiO2; Ru-doped TiO2; bandgap reduction; high-k; leakage current.