Design of non-volatile capacitive memory using axial type-II heterostructure nanowires of NiO/β-Ga₂O₃

The study presents a non-volatile memory (NVM) device created from an axial NiO-nanowire (NW)/β-Ga₂O₃-NW heterostructure (HS) using GLAD within the RF/DC sputtering chamber. The device performance of the axial NiO-NW/β-Ga₂O₃-NW HS was compared to the NiO-thin film (TF)/β-Ga₂O₃-TF HS device. Moreover, the axial NiO-NW/β-Ga₂O₃-NW HS sample superior crystallinity as compared to its 2-D HS counterpart confirming a high degree of structural alignment in case of axial HS NW. The axial NiO-NW/β-Ga₂O₃-NW HS device showed a high accumulation capacitance of 25 pF and a conductance of 28 × 10⁻⁶ S measured at 1 MHz frequency. Furthermore, the axial NiO-NW/β-Ga₂O₃-NW HS memory device displayed good characteristics including a low interface state density ( \({D}_{it}\) $D_{\mathit{it}}$ ) of 1.13 × 10¹¹ eV⁻¹ cm⁻² and a significant memory window of 2.84 V at ± 8 V sweeping voltage as compared to the TF HS ( \({D}_{it}\) $D_{\mathit{it}}$ of 1.42 × 10¹¹ eV⁻¹ cm⁻² and memory window of 0.56 V at ± 8 V). Additionally, the axial NiO-NW/β-Ga₂O₃-NW HS memory device exhibited good endurance over 1000 programming/erasing cycles as well as reliable retention properties (memory window stays constant up to 3 × 10⁴ s). Therefore, axial NiO-NW/β-Ga₂O₃-NW HS memory device, benefiting from the high-quality type-II junction emerges as a promising choice for future NVM applications.