Improved Capacitive Memory in Glancing Angle Electron-Beam Synthesized Isotropic Bilayer n-TiO2/In2O3 Nanowires Array

We report on the memory performance study of vertically stacked TiO
₂
/In
₂
O
₃
metal oxides heterostructure (MOH) nanowire (NW). Two typical structures p-Si/TiO
₂
TF/TiO
₂
NW/Ag and p-Si/TiO
₂
TF/TiO
₂
NW/In
₂
O
₃
NW/Ag device were deposited using electron-beam evaporator incorporating glancing angle deposition technique. Frequency dependent studies ranging from 1 MHz to 6 MHz on capacitance-voltage characteristic was conducted to investigate charge trapping nature of both devices. TiO
₂
/In
₂
O
₃
MOH NW displayed wide memory window of 8.8 V and low interface trap density (D
_it
) ∼2.55 × 10
¹¹
eV
⁻¹
cm
⁻²
. Flat band voltage shift (ΔV
_FB
) was obtained from CV hysteresis and the electron as well as hole trapping density were found for the devices. In addition, the endurance of ON/OFF switching cycles for the TiO
₂
/In
₂
O
₃
MOH NW device was up to 1000 cycles. A resistance ON/OFF ratio of ∼20 was displayed with a stable retention time of 6500 s showing improved performance and reliability compared to TiO
₂
NW with resistance ON/OFF ratio of ∼3 and unstable retention time. Our work delivers an opportunity for developing the next generation stable and high-performance nonvolatile memory devices.