Resistive switching phenomena of tungsten nitride thin films with excellent CMOS compatibility

We report the resistive switching (RS) characteristics of tungsten nitride (WNx) thin films with excellent complementary metal-oxide-semiconductor (CMOS) compatibility. A Ti/WNx/Pt memory cell clearly shows bipolar RS behaviors at a low voltage of approximately ±2.2 V. The dominant conduction mechanisms at low and high resistance states were verified by Ohmic behavior and trap-controlled space-charge-limited conduction, respectively. A conducting filament model by a redox reaction explains the RS behavior in WNx films. We also demonstrate the memory characteristics during pulse operation, including a high endurance over >105 cycles and a long retention time of >105 s.