Abstract:
Non-volatile memory technology plays a important role in the market of electronics products.
Until now, Flash memory dominates the market of non-volatile memories, which is based on
traditional floating gate concept. With rapid scaling of microelectronic technology, it has
encountered serious technical challenges. To overcome these challenges Resistive Random
Access Memory (ReRAM) is a promising candidate for next generation of non-volatile memory.
In the present study c-axis oriented Pulsed Laser Deposited Ag/MgxZn1-xO/Cu//Si structure was
investigated for its Resistive switching behaviour. The presence of (002) and (103) MgxZn1-xO
peaks without any impurity phases in X-ray diffraction confirms the presence of sharp and abrupt
interface formation between MgxZn1-xO and the electrode layers. The cross sectional FE-SEM
studies were further carried out to examine the quality of the interface. The room temperature I-V
characteristic of the thin films was conducted using Keithley 4200-SCS (Semiconductor
characterization system) to analyze the resistive switching mechanism. I-V characterization of
the thin films revealed the bipolar nature of resistive switching and presence of two resistance
states i.e. High Resistance (HR) and Low Resistance (LR) which can be switched at relatively
low voltage ~ 3V magnitude. The durability of Non-Volatile Memory nature of the
heterostructure was also examined by Keithely 4200 using the ± 4V voltages applied in closed
loops. The Resistive Switching behaviour present in the MgxZn1-xO thin film was explained by
formation and rupture of the nano-scale conduction filament due to Oxygen vacancies. The
leakage analysis revealed the dominance of Ohmic conduction in LRS region and Poole Frenkel
emission in HRS region. Improvement in resistive switching behaviour is observed by
substitution of Mg in ZnO thin film. Such a Silicon integrated low voltage tuned MgxZn1-xO thin
film having non volatile two resistance states could prove useful in future power efficient
memory devices.
