A method of generating random bits by using electronic bipolar memristor*

Abstract

The intrinsic stochasticity of resistance switching process is one of the holdblocks for using memristor as a fundamental element in the next-generation nonvolatile memory. However, such a weakness can be used as an asset for generating the random bits, which is valuable in a hardware security system. In this work, a forming-free electronic bipolar Pt/Ti/Ta2O5/Pt memristor is successfully fabricated to investigate the merits of generating random bits in such a device. The resistance switching mechanism of the fabricated device is ascribed to the electric field conducted electrons trapping/de-trapping in the deep-energy-level traps produced by the “oxygen grabbing” process. The stochasticity of the electrons trapping/de-trapping governs the random distribution of the set/reset switching voltages of the device, making a single memristor act as a random bit in which the resistance of the device represents information and the applied voltage pulse serves as the triggering signal. The physical implementation of such a random process provides a method of generating the random bits based on memristors in hardware security applications.