High-/spl kappa/ HfO2/TiO2/HfO2 multilayer quantum well flash memory devices

High-kappa HfO
₂
/TiO
₂
/HfO
₂
multilayer quantum well (MQW) charge storage devices with a large memory window of DeltaV
_t
ap8.1 V, an excellent endurance and a good retention (~9% charge loss at 20degC) are reported. Both program and erase speeds of DeltaV
_t
>3 V@100 mus are achieved for memory transistors under channel hot carrier injections. Furthermore, quantum well memory capacitors with high-kappa Al
₂
O
₃
as a blocking oxide and high work function metal gate show low leakage current density of ~2.4times10
^-7
A/cm
²
@V
_g
=-5 V at 125degC and high program/erase speed of DeltaV
_FB
>2 V@10 mus with a low operation voltage of V
_g
<5 V.