ReRAM crossbar array: Reduction of access time by reducing the parasitic capacitance of the selector device

The transient response of a crossbar array is investigated with HSPICE circuit simulation. A crossbar array contains many parasitic elements. This brief focuses on the parasitic capacitances of the selector devices and resistors. The read access time is determined for various array sizes and parasitic capacitances. The results show that the read access time increases with the array size and parasitic capacitance, particularly the selector capacitance. The effect of selector capacitance is analyzed with a time-dependent, unit-cell voltage model and simulation. The simulation results reveal that the selector capacitance has a greater effect than the resistor capacitance on the read access time because of the large time constant. The effect of the selector capacitance on the read access time remains significant for larger values of the other parasitic capacitances.