Addressing crosstalk in crossbar memory arrays with a resistive switching ZnO homojunction diode

Abstract

A resistive switching ZnO n-n homojunction diode fabricated with a stack of two dissimilar ZnO thin films shows promising characteristics necessary to address the crosstalk problem in a crossbar memory array. The device has a characteristic I-V-hysteresis loop in forward bias, in conjunction with its n-n junction characteristics. In the ac frequency range of 10 Hz-15 kHz, the area inside the hysteresis loop initially increased, reaching a maximum at 1 kHz, and then decreased with increasing frequency. The maximum in the area of the hysteresis loop corresponds to the accumulation of space charge at the interface. The resistivity of the device was found to vary from 5 to 100 kω in the bias range of 0-10 V and in the range of 106 ω when reverse biased; the ratio of high resistive state to low resistive state has its maximum (∼2.4) at 1 kHz ac signal at 3 V.