Low-Power and Nanosecond Switching in Robust Hafnium Oxide Resistive Memory With a Thin Ti Cap

The memory performance of hafnium oxide (HfO
_x
)-based resistive memory containing a thin reactive Ti buffer layer can be greatly improved. Due to the excellent ability of Ti to absorb oxygen atoms from the HfO
_x
film after post-metal annealing, a large amount of oxygen vacancies are left in the HfO
_x
layer of the TiN/Ti/HfO
_x
/TiN stacked layer. These oxygen vacancies are crucial to make a memory device with a stable bipolar resistive switching behavior. Aside from the benefits of low operation power and large on/off ratio (>100), this memory also exhibits reliable switching endurance (>10
⁶
cycles), robust resistance states (200°C), high device yield (~100%), and fast switching speed (<10 ns).