Uniform bipolar resistive switching properties with self-compliance effect of Pt/TiO2/p-Si devices

Abstract

We report uniform bipolar resistive switching characteristic with self-compliance effect of Pt/TiO2/p-Si devices in which TiO2 thin films were prepared directly on p-Si substrates by chemical solution deposition method. The resistive switching parameters of the Pt/TiO2/p-Si cell obtained, such as distribution of threshold voltages, retention time, as well as resistance variation of high resistance state (HRS) and low resistance state (LRS), were investigated, and the conduction mechanisms of HRS and LRS were analyzed. The conductive mechanism at LRS and low voltage region of HRS was dominated by Ohmic law. At the high voltage region of HRS, the conductive mechanism followed the space charge limited current theory. The resistive switching phenomenon can be explained by electron trapping and de-trapping process, in which the defects (most probably oxygen vacancies) act as electron traps. Our study suggests that using p-type silicon as bottom electrode can provide a simple method for fabricating a resistive random access memory with self-compliance function. In addition, the Pt/TiO2/p-Si configuration is compatible with complementary metal oxide semiconductor process.