One Bipolar Selector-One Resistor for Flexible Crossbar Memory Applications

A bipolar, highly nonlinear n-p-n selector is coupled in series with resistive switching memory device to suppress the sneak path current. The memory characteristics are measured for the crossbar array fabricated on a flexible polyethylene terephthalate substrate. Dominant conduction mechanism is the Zener tunneling to obtain the high nonlinearity in the selector device. This phenomenon validates the I-V characteristics which are temperature dependent, which leads to decrease in the turn-on voltage of the device as the temperature increases. The proposed one bipolar selector-one resistor device demonstrates better memory characteristics with the high nonlinearity (similar to 10(3)), observable memory window of about one order, excellent ac endurance (10(7)) cycles, fast switching speed (60 ns), and stable retention (10(4) s) at 100 degrees C. The results show the substantial potential of the proposedone selector-one-resistor structure in suppressing the leakage current, making it attractive for future high-density flexible crossbar memory array.