Quantized Conductance in Ta_2O_5 Based Resistive Random Access Memory Devices

摘要

We report quantised conductance in Au/Ta_2O_5/Pt structures grown by pulsed laser deposition. Quantum conduction phenomenon was observed during reset switching event of resistive switching in tantalum oxide (Ta_2O_5) thin films. Nonvolatile and repeatable electric field controlled unipolar resistive switching was clearly seen in Au/Ta_2O_5/Pt structures with good endurance. The quantum conduction phenomenon has been attributed to formation of nanometer scale conducting filaments which constraints the motion of electron in transverse direction resulting in quantisation of device conductance in half integer multiple of fundamental unit of conductance G_0 (2e~2/h). These quantised conductance results in well separated resistance states, suitable for realising futuristic multi-bit resistance switching memory.