Abnormal Volatile Memory Characteristic in Normal Nonvolatile ZnSnO Resistive Switching Memory

Resistive random access memory is known as a type of nonvolatile memory. An abnormal volatile memory characteristic of a normal ZnSnO resistive memory is first demonstrated in this paper. Although the I-V curves exhibit a normal and stable resistive switching memory behavior, the resistance state is found to be only determined by the initial applied voltage along with the voltage sweep direction. It is set/reset processes free. Namely, it is volatile. The resistance states are found to be dominated by trap-assisted tunneling, trap-controlled space-charge-limited conduction, and hopping transport. Different resistance states are related to different carrier transport mechanisms. Each resistance state can independently and repeatably appear for over 1000 voltage sweeps. The ratio of the high-resistance state to the low-resistance state is similar to 3 x 10(2).