Resistive Random Access Memory (RRAM): an Overview of Materials, Switching Mechanism, Performance, Multilevel Cell (mlc) Storage, Modeling, and Applications

Table 5 Comparison of RRAM models

	ASU/Stanford [130]–[132]	Physical electro-thermal model [135]	Huang’s physical model [142]	Filament dissolution model [143]–[145]	Bocquet bipolar model [148]
Device type	Bipolar	Bipolar	Bipolar	Unipolar	Bipolar
State variable	Filament gap (g)	Ion concentration	Filament gap (g)	Ion concentration	Radius of CF
			and width of CF
Control mechanism	Voltage	Voltage	Voltage	Voltage	Voltage
Simulation compatible	SPICE/Verilog	COMSOL	SPICE	COMSOL	SPICE