RESET-first Resistance Switching Mechanism of HfO2 films with Ti electrode

RESET-first resistive switching mechanism in HfO
_2-x
with Ti electrode was studied. RESET resistive switching was observed in annealed Ti/HfO
₂
film. The redox phenomenon from Ti/HfO
₂
to TiO
_x
/HfO
_2-x
was investigated with high angle annular dark field-scanning transmission electron microscopy, EDX, and x-ray photoelectron spectroscopy. Analysis shows that redox reaction from Ti/HfO
₂
to TiOx/HfO
_2-x
was responsible for an increase of initial current with increasing the post-annealing temperature and the migration of oxygen ions at interface region under external electrical bias was contributed to bipolar resistive switching behavior.