Metal-insulator-semiconductor bipolar transistor as a 4F2 vertical RRAM selection device

The metal-insulator-semiconductor bipolar transistor detects the injection of minority carriers through a resistive switching element into a semiconductor electrode. We propose that this device may serve as a selection device for bipolar resistive switching elements in large memory crossbar arrays. The selection is accomplished by inspection of the highly non-linear minority carrier current. The experimental device provides non-linearity of about ~80 mV/decade, but 60 mV/decade is feasible. The device may potentially be confined into the minimal 4F² footprint. The selection properties of the device are discussed, and compared to those of alternative selection devices suitable for bipolar switching elements.